Autosorb-6iSA
Gas Sorption System
Operating Manual
Model: AS6-i-1
ASWin Version: 2.03
Original Instructions (English)
I08IB001EN-D
© 2009–2020
Quantachrome Instruments
A brand of Anton Paar
1900 Corporate Drive
Boynton Beach FL 33426
USA
Autosorb-6iSA/ASWin Operating Manual
Disclaimer
This document may contain errors and omissions. If you discover any such errors or if you would like to
see more information in this document, please contact us at our address below. Anton Paar assumes no
liability for any errors or omissions in this document.
Changes, copyright, trademarks etc.
This document and its contents may be changed or amended by Anton Paar at any time without prior
notice.
All rights reserved (including translation). This document, or any part of it, may not be reproduced,
changed, copied, or distributed by means of electronic systems in any form (print, photocopy, microfilm
or any other process) without prior written permission of Anton Paar GmbH.
Trademarks, registered trademarks, trade names, etc. may be used in this document without being marked
as such. They are the property of their respective owner.
Further information
Published and printed by Anton Paar QuantaTec, Inc.
Copyright © 2020 Anton Paar GmbH, Graz, Austria
Address of the instrument producer:
Anton Paar QuantaTec, Inc.
1900 Corporate Drive
Boynton Beach, Florida 33426 - USA
E-Mail: info@anton-paar.com
Web: www.anton-paar.com
Date: April, 2020
Document number: I08IB001EN-D
2 of 158
Autosorb-6iSA/ASWin Operating Manual
TABLE OF CONTENTS
TABLE OF CONTENTS
TABLE OF CONTENTS ............................................................................................. 3
A. INTRODUCTION ................................................................................................... 8
1
Summary of Instrument Features ........................................................................................ 8
2
Summary of ASWin Software Features............................................................................... 9
3
Technical Specifications ...................................................................................................... 10
B. SAFETY ................................................................................................................... 11
1
Symbols Used In This Manual ........................................................................................... 11
2
Safety Instructions for the Autosorb-6iSA .................................................................... 11
C. INSTALLATION .................................................................................................... 13
1
Initial Installation.................................................................................................................. 13
2
1.1
Unpacking ...................................................................................................................................... 13
1.2
Location .......................................................................................................................................... 13
1.3
Operating Voltage......................................................................................................................... 13
1.4
UPS Installation............................................................................................................................. 14
1.5
Vacuum Pump ............................................................................................................................... 14
1.5.1
Voltages ..................................................................................................................................... 14
1.5.2
Hose Connection ..................................................................................................................... 15
1.5.3
Adding Oil to Oil Pump......................................................................................................... 15
1.6
Gas Connections ........................................................................................................................... 16
1.7
Instrument Overview ................................................................................................................... 17
1.7.1
Autosorb-6iSA Front Panel Controls................................................................................... 17
1.7.2
Analysis Stations ...................................................................................................................... 20
1.7.2.1
Sample Cells and Glass Filler Rods ............................................................................. 20
1.7.2.2
Cell Bulkhead Fittings.................................................................................................... 20
1.7.2.3
Dewar Flask..................................................................................................................... 21
1.7.2.4
Dewar Shield ................................................................................................................... 21
1.7.3
Right Side Panel ....................................................................................................................... 22
1.7.3.1
Calibration Chamber ...................................................................................................... 22
1.7.3.2
Vacuum Gauge ............................................................................................................... 22
1.7.4
Rear Panel ................................................................................................................................. 22
1.7.4.1
Mains Power Switches ................................................................................................... 22
1.7.4.2
Power Select and UPS Socket ...................................................................................... 22
1.7.4.3
USB Port .......................................................................................................................... 22
1.7.4.4
Gas lines........................................................................................................................... 22
1.7.4.5
Vacuum Pump Power Supply ....................................................................................... 23
2.1
2.2
2.3
ASWin Software Installation .............................................................................................. 23
Connecting the PC to the Autosorb-6iSA ............................................................................. 23
Software Installation ..................................................................................................................... 23
Instrument Power Up .................................................................................................................. 26
D. SOFTWARE CONFIGURATION ........................................................................ 27
1
Initial Launching of ASWin Software ............................................................................... 27
1.1
Non-CFR version ......................................................................................................................... 27
1.1.1
User Login ................................................................................................................................ 27
1.1.2
Changing User.......................................................................................................................... 28
1.2
CFR Version .................................................................................................................................. 28
1.2.1
Initial Security Configuration................................................................................................. 28
3 of 158
Autosorb-6iSA/ASWin Operating Manual
2
3
4
1.2.2
1.2.3
1.2.4
TABLE OF CONTENTS
Creating Superuser Account .................................................................................................. 30
Login .......................................................................................................................................... 30
Re-Login.................................................................................................................................... 32
ASWin Menu System ........................................................................................................... 32
2.1
Main Menu — No Security ......................................................................................................... 33
2.2
Main Menu — Security Access Levels ...................................................................................... 34
2.2.3
Main Menu Options – Superuser Level ............................................................................... 35
2.2.4
Main Menu Options – Manager Level ................................................................................. 35
2.2.5
Main Menu Options – Operator Level ................................................................................ 35
2.3
Assigning Access Levels to New Users ..................................................................................... 36
2.4
Reviewing/Editing User Properties ........................................................................................... 37
2.5
Disabling/Enabling Users ........................................................................................................... 38
2.6
Changing (your own) Password .................................................................................................. 39
4.1
4.2
4.3
4.4
Communication Setup ......................................................................................................... 39
Configure Options ............................................................................................................... 40
Manage Materials: Edit Adsorbate Parameters ........................................................................ 40
Manage Materials: Edit Adsorbent Parameters ........................................................................ 43
Edit Data Reduction Parameters (DRP) ................................................................................... 43
Set Data Folders ............................................................................................................................ 44
E. SAMPLE PREPARATION .................................................................................... 46
1
Sample Cell Selection ........................................................................................................... 46
2
Methods of Sample Preparation......................................................................................... 46
3
Choice of Degas Temperature and Degassing Time ...................................................... 47
4
Elutriation and Its Prevention (Vacuum Degassing) ...................................................... 48
5
Choice of Backfill Gas (Vacuum Degassing) ................................................................... 48
6
Flow Degassing..................................................................................................................... 49
7
Cooling the Sample Cell ...................................................................................................... 49
F. INSTRUMENT OPERATION ............................................................................. 50
1
Manifold Calibration (infrequent) ...................................................................................... 50
2
Void Volume Determination (automatic every analysis) ................................................ 51
3
Sample Analysis Setup ......................................................................................................... 52
3.1
Sample Parameters (Admin)........................................................................................................ 53
3.2
Analysis Parameters ...................................................................................................................... 55
3.2.1
Adsorbate .................................................................................................................................. 56
3.2.2
Adsorbate Parameters ............................................................................................................. 57
3.2.3
Evacuation ................................................................................................................................ 57
3.2.4
Initial Fill ................................................................................................................................... 57
3.2.5
MaxiDose enabled ................................................................................................................... 57
3.2.6
Leak Test................................................................................................................................... 57
3.2.7
P0 Options................................................................................................................................ 57
3.3
Start Analysis Error Messages..................................................................................................... 58
3.4
Selecting Points ............................................................................................................................. 59
3.4.1
Adding a Single Point ............................................................................................................. 61
3.4.2
Adding Range of Points ......................................................................................................... 61
3.4.3
Standard Point Sets ................................................................................................................. 61
3.4.3.1
BET points ...................................................................................................................... 61
3.4.3.2
Adsorption/Desorption Points ................................................................................... 61
3.4.3.3
Micropore Point Selection (Autosorb 6 Kr users only) ........................................... 62
3.4.4
Modifying the List of Points .................................................................................................. 63
3.4.5
Equilibration Criteria .............................................................................................................. 63
4 of 158
Autosorb-6iSA/ASWin Operating Manual
4
5
TABLE OF CONTENTS
3.5
Data Reduction and Analysis Reporting Page.......................................................................... 64
3.5.1
Auto-report ............................................................................................................................... 64
3.5.2
Archive Result .......................................................................................................................... 65
3.5.3
Set Data Reduction.................................................................................................................. 65
3.6
Viewing Summary of Analysis Parameters ............................................................................... 66
5.1
5.2
5.3
5.4
5.5
Saving/Retrieving Analysis Parameters ............................................................................ 67
Start and Monitor Analysis ................................................................................................. 67
Instrument Message Log/Monitor Instrument ....................................................................... 68
Instrument Status Dashboard ..................................................................................................... 70
Uploading Data Points ................................................................................................................. 70
Abort Analysis ............................................................................................................................... 71
Manual Mode ................................................................................................................................. 72
G. DATA ANALYSIS USING ASWIN ....................................................................... 74
1
Accessing Data Files ............................................................................................................ 74
2
File Types .............................................................................................................................. 74
3
4
5
6
7
8
9
2.1
2.2
3.1
3.2
4.1
4.2
“Open” 74
“Import” ......................................................................................................................................... 75
Using the Database for Searching .qps Data Files .......................................................... 76
Locating Analysis Results ............................................................................................................ 76
Rebuilding Physisorption Database ........................................................................................... 77
Floating Menu....................................................................................................................... 78
Floating Menus on Plots .............................................................................................................. 78
Floating Menus on Tables ........................................................................................................... 79
Editing Analysis Data Information.................................................................................... 79
Setting Data Reduction Tags .............................................................................................. 80
Setting Data Reduction Parameters ................................................................................... 82
7.1
Parameters for NLDFT and GCMC Methods ........................................................................ 84
7.2
Review of the Data Analysis Methods....................................................................................... 86
7.2.1
HK: Horvath Kawazoe Method SF: Saito Foley Method ................................................ 86
7.2.2
DA: Dubinin Astakhov Method ........................................................................................... 86
7.2.3
BJH: Barrett, Joyner & Halenda Method DH: Dollimore Heal Method ....................... 86
7.2.4
DR: Dubinin Radushkevich Method.................................................................................... 88
7.2.5
BET: Brunauer, Emmett, & Teller Method ........................................................................ 88
7.2.6
Langmuir Surface Area ........................................................................................................... 91
7.2.7
t-plot: Statistical Thickness Methods.................................................................................... 91
7.2.8
alpha-s Method ........................................................................................................................ 92
7.2.9
MP Method............................................................................................................................... 92
7.2.10 FHH: Frenkel-Halsey-Hill Method NK: Neimark Kiselev Method ............................... 93
7.2.11 Total Pore Volume .................................................................................................................. 93
7.2.12 Average Pore Size .................................................................................................................... 93
Kr-87 K Pore Size Analysis Method ................................................................................. 93
Calculation of Isosteric Heats of Adsorption .................................................................. 94
H. DATA PRESENTATION USING ASWIN .......................................................... 96
1
Interactive Modification of Tag Selection ....................................................................... 97
2
Configuring Graph Properties............................................................................................ 98
3
Configuring Table Properties ........................................................................................... 100
4
Creating Overlay Plots....................................................................................................... 101
5
Generating Custom Reports ............................................................................................. 104
6
Modifying Custom Reports .............................................................................................. 106
5 of 158
Autosorb-6iSA/ASWin Operating Manual
TABLE OF CONTENTS
Saving Tables as Text......................................................................................................... 107
Changing Header Information ......................................................................................... 108
7
8
I. THEORY AND DISCUSSION.............................................................................. 109
1
Surface Area ........................................................................................................................ 109
2
3
4
5
6
7
8
1.1
1.2
1.3
Multipoint BET Method ............................................................................................................ 109
Single Point BET Method ......................................................................................................... 110
Multipoint/Single Point Comparison ...................................................................................... 111
Pore Size by Gas Adsorption ........................................................................................... 113
Adsorption-Desorption Isotherms .................................................................................. 113
3.1
Isotherm Types ........................................................................................................................... 113
3.2
Hysteresis Types.......................................................................................................................... 114
3.3
Total Pore Volume and Average Pore Radius ....................................................................... 116
3.4
Pore Size Distributions (Mesopore) ......................................................................................... 116
3.4.1
BJH Method ........................................................................................................................... 117
3.4.2
DH Method ............................................................................................................................ 119
3.5
Surface Area of Microporous Samples by Langmuir Method ............................................. 119
4.1
4.2
4.3
4.4
4.5
4.6
4.7
7.1
7.2
Micropore Analysis ............................................................................................................ 120
V-t Method................................................................................................................................... 120
Alpha-s (αs) Method ................................................................................................................... 123
MP Method .................................................................................................................................. 123
Dubinin-Radushkevich (DR) Method ..................................................................................... 124
Dubinin-Astakhov (DA) Method ............................................................................................. 126
Horvath-Kawazoe (HK) Method ............................................................................................. 127
Saito-Foley (SF) Method ............................................................................................................ 129
Density Functional Theory and Monte Carlo Simulation Methods ........................... 130
Thermal Transpiration....................................................................................................... 133
Fractal Dimension Methods ............................................................................................. 134
Frenkel-Halsey-Hill (FHH) Method ........................................................................................ 134
Neimark-Kiselev (NK) Method................................................................................................ 135
Differential Heat of Adsorption ...................................................................................... 136
J. APPENDICES ........................................................................................................ 137
1
System Error Messages...................................................................................................... 137
2
P/Po Tolerance .................................................................................................................. 138
3
Autosorb Dosing Routine and Equilibration Time ...................................................... 139
4
Analysis Gas Selection ....................................................................................................... 140
5
Krypton Operations (legacy Autosorb-6B only) ........................................................... 142
6
Sample Cells ........................................................................................................................ 143
7
6.1
6.2
6.3
6.4
7.1
7.2
7.3
Standard Physisorption Cells .................................................................................................... 143
Two-piece Sample Cells ............................................................................................................. 144
Valved Sample Cells ................................................................................................................... 145
Saturation Pressure Cell ............................................................................................................. 145
Maintenance Addendum ................................................................................................... 147
Maintenance performed by an authorized Anton Paar Service Engineer ......................... 147
Upkeep and Cleaning ................................................................................................................. 147
In Case a Repair is Required ..................................................................................................... 148
K. VACUUM PUMP MAINTENANCE ................................................................... 148
2
1.1
Checking / Adjusting Flow Rates Input Pressure ................................................................. 148
Repair ................................................................................................................................... 151
6 of 158
Autosorb-6iSA/ASWin Operating Manual
3
4
5
4.1
4.2
4.3
5.1
5.2
TABLE OF CONTENTS
Troubleshooting Guide ..................................................................................................... 152
Storage and Transport ....................................................................................................... 154
Overnight ..................................................................................................................................... 154
Short-term shut down ................................................................................................................ 154
Long-term shut down................................................................................................................. 154
ASWin Software Installation Instructions for Windows® Vista Users ....................... 155
General Notes ............................................................................................................................. 155
Remarks ........................................................................................................................................ 155
REFERENCES .......................................................................................................... 156
7 of 158
Autosorb-6iSA/ASWin Operating Manual
A. INTRODUCTION
A. INTRODUCTION
The Autosorb-6iSA measures the quantity of gas adsorbed onto or desorbed from a solid surface
at some equilibrium vapor pressure by the static volumetric (manometric) method. Data are
obtained by admitting or removing a known quantity of adsorbate gas into or out of a sample cell
containing the solid adsorbent maintained at a constant temperature, usually below the critical
temperature of the adsorbate. As adsorption or desorption occurs the pressure in the sample cell
changes until equilibrium is established. The quantity of gas adsorbed or desorbed at the
equilibrium pressure is the difference between the amount of gas admitted (dosed) or removed
and the amount required to fill the sample cell and the space around the adsorbent (void volume
or free space). This manual describes the installation of the unit, its discrete components and
associated PC software program (ASWin), and proper use so that you can obtain reliable surface
area and pore size distribution results.
1
Summary of Instrument Features
•
The Autosorb-6iSA can measure adsorbed or desorbed volumes of nitrogen at relative
pressures (P/Po) in the range 0.001 to slightly less than 1.0.
•
Each of the six analysis stations is comprised of a sample cell port, a dedicated Po port,
coolant level sensor, its own 2L dewar flask and dewar shield.
•
Each dewar consists of a high-quality glass liner inside a protective metal can fitted with a
comfortable handle.
•
Each sample port can accommodate a variety of sample cells with stem diameters of 6mm,
9mm or 12mm.
•
Coolant level sensors assure a constant level of cooant around the sample cell while
minimizing cold free space volume (cold zone).
•
Sample can be loaded and started while other samples are still running.
•
The unit is equipped with a dedicated calibration port for manifold volume calibration as
required by your laboratory procedures.
•
The unit can be installed on a bench top, or on an accessory rolling cart (purchased
separately).
•
Instrument status is clearly displayed via indicator LED’s, multi-function digital
pressure/temperature display and digital vacuum gauge.
•
The unit has a USB port for communication to a Windows-based PC running ASWin
software.
8 of 158
Autosorb-6iSA/ASWin Operating Manual
2
A. INTRODUCTION
Summary of ASWin Software Features
•
Menu-driven, easy-to-use software allows user to collect, display, analyze, and archive data.
•
User-defined analysis setup files enable flexible, reproducible and simplified operation of the
Autosorb.
•
Plots of data are automatically generated on-screen during an analysis.
•
During a run, each data point can be acquired and saved to the data file so that in the event of
an error condition, such as a power loss, data that has been acquired will not be lost.
•
Data files can be automatically archived across a local network at the end of an analysis.
•
Results and calculations include surface area, pore size distribution, fractals, heats of
adsorption.
•
Graphical plots can be overlaid and have customizable axis scaling, colors and data point
markers.
•
Any PC running ASWin software can be used to review data files and generate detailed
reports.
•
This software can read data files generated by other Quantachrome gas sorption analyzers:
Autosorb-iQ, Autosorb-1, Autosorb-6B, Quadrasorb, NOVAe.
•
Customizable formats simplify and automate report generation.
•
The CFR version of ASWIn software has 21CFR-Part 11 features:
a) Tamper-evident data files
b) Required system login with unique user name and password combination
c) Password expiration and lockout after failed password attempts
d) Fully detailed audit trail
e) 3 access levels programmable by system administrator
f) Programmable session time-out (auto logoff)
g) Unique report identification
•
Not copy-protected. You may install the software on any number of PC’s within your facility
for data reduction and report generation – not just the PC connected to the Autosorb-6iSA.
The software is however copyrighted and may not be distributed to a third party (see Terms
and Conditions of Sale, above).
9 of 158
Autosorb-6iSA/ASWin Operating Manual
3
A. INTRODUCTION
Technical Specifications
Autosorb-6iSA Instrument
PHYSICAL
Height: ................................................... 137.6 cm (54.0 in.)
Width ..................................................... 67.3 cm (26.5 in.)
Depth: .................................................... 88.9 cm (35.0in.). Allow 10-15cm (4-6in.) additional
clearance at rear
Weight ................................................... 169kg (372 lbs.)
ELECTRICAL
Voltage: ................................................. 95 – 240 VAC (see serial number plate on rear of unit)
Frequency: ............................................. 50/60 Hz
Power (max): ......................................... 870VA (including pump, 370VA)
Connection: ............................................ Grounded, single-phase outlet
ENVIRONMENTAL
Temperature: .......................................... 10 °C-38 °C
Max. Relative Humidity: ........................ 90 % (non-condensing)
Atmosphere: .......................................... non-hazardous; no flammable gases or dust
Noise emission: ..................................... <68 dBA
Ingress protection: ................................. IP40D (IEC 60529)
10 of 158
Autosorb-6iSA/ASWin Operating Manual
B. SAFETY
B. SAFETY
1
Symbols Used In This Manual
HOT! This sign denotes a possible hazard to the operator due to high temperatures.
!
CAUTION! This sign denotes a hazard that could result in damage to the
instrument.
!
WARNING! This sign denotes a hazard that could result in injury to the operator.

NOTE! This sign denotes an important detail.

TOOLS REQUIRED: This signifies that tools are required for the described
action.
These symbols refer to the 21 CFR-Part 11 compliant version, where S =
Superuser, M = manager and O = operator. A cross through the symbol
denotes that that security level does not have the capability described in
that section.
2
Safety Instructions for the Autosorb-6iSA
•
This instrument has been designed for laboratory use only.
•
The Autosorb-6iSA requires a trained operator to use the instrument.
•
This instrument shall not be used for any application other than that for which it was
designed.
•
When filling Dewar flask with liquid nitrogen (LN2) care must be taken to prevent it from
getting between the glass insert and the outer cover, as this could cause the glass to implode.
•
Because the Dewar flask could shatter unexpectedly, a protective face shield, goggles or full
wrap-around safety glasses, and gloves should be worn when filling the flasks.
•
When using a gas other than N2 not at its boiling point, do not use the Calculate P0 option for
the analysis.
•
Operate this instrument only at the voltage specified on the serial number plate on the rear of
11 of 158
Autosorb-6iSA/ASWin Operating Manual
B. SAFETY
the instrument.
•
Inform yourself regarding hazards associated with the sample under test.
•
Inform yourself regarding hazards associated with the gas(es) used.
•
This instrument must be disconnected from the mains for any cleaning, maintenance or
service.
•
Do not make any unauthorized modifications to this instrument.
•
Position the instrument in such a way that the on/off switch can be accessed easily.
•
When attaching a plug to the power cord, be sure to follow the color code shown below:
Brown = live, blue = neutral, green/yellow = earth ground
12 of 158
Autosorb-6iSA/ASWin Operating Manual
D. SOFTWARE CONFIGURATION
C. INSTALLATION
1
1.1
Initial Installation
Unpacking
Carefully remove the instrument and all parts from the shipping container. Inspect them for
shipping damage or missing parts. Immediately notify the carrier if any damage is discovered.
Retain the original packing material for at least the warranty period in case of return to the
factory for service or repair. Compare the entire contents against the packing list. Inspect the
parts for shipping damage and immediately notify the carrier if any damage is discovered.
1.2
Location
The instrument should be installed on a level bench capable of supporting at least 180 kg
(400lbs) and that is at a comfortable working height for the operator and away from any sources
of radiated heat and condensation.
!
WARNING! Use appropriate lifting equipment to ensure safe handling due to the
size and weight of the instrument.
Position the instrument so that you can easily access the on/off switch in case it is necessary to
power off the Autosorb-6iSA.
1.3
Operating Voltage
The Autosorb-6iSA is designed for operation at certain voltages within the range 95-240V,
50/60Hz. Your unit was set to operation at the voltage specified at the time of purchase and is
indicated on the serial number plate affixed to the rear of the unit, according to Table C.1.
Table C.1. Autosorb-6iSA Operating Voltages
Mains
Frequency
Your Mains Voltage
Nominal Mains Voltage
Indicated on
6 iSA serial number plate
50/60
95-105
100
50/60
107-127
115
50/60
208-228
215
50/60
230-240
230
13 of 158
Autosorb-6iSA/ASWin Operating Manual
D. SOFTWARE CONFIGURATION
!
CAUTION! Do not power the unit up at this time.
!
CAUTION! The Autosorb-6iSA is factory set to the nominal input voltage
indicated on the serial number plate. The mains cord must only be connected to
the indicated voltage range shown in Table C.1.
Installation of a UPS (Uninterruptible Power Supply) is recommended.
1.4
UPS Installation
!
CAUTION! The UPS Output voltage must be 115VAC, regardless of the
instrument’s input (mains) voltage.
Refer to the UPS manual for operating instructions for the UPS itself.
The following steps describe how to install a UPS on the Autosorb-6iSA instrument:
1 Switch ALL circuit breakers OFF.
2 Move rocker switch (located on the back of the Autosorb-6iSA) down FROM MAINS to
the VIA UPS position.
3 Plug in the UPS’ output to the UPS IN socket below the rocker switch.
4 Turn on the UPS and then turn both Autosorb-6iSA breakers back on.
1.5
1.5.1
Vacuum Pump
Voltages
The pump supplied with the Autosorb-6iSA operates at 50/60 Hz. Check the label on the pump
motor for its voltage requirement before plugging it into the outlet socket at the rear of the
Autosorb-6iSA. The pump must match your mains value according to the table below:
Table C.2, Vacuum Pump Operating Voltages
Mains
Frequency
Your Mains
Voltage
Matching Voltage
on Pump Motor
50
95-120
95-120
60
105-120
105-120
50
200-240
200-240
60
208-240
208-240
14 of 158
Autosorb-6iSA/ASWin Operating Manual
1.5.2
D. SOFTWARE CONFIGURATION
Hose Connection
The Autosorb-6iSA has a vacuum hose already attached, terminating in a KF/NW-16 flange for
connection to the vacuum pump (see below) at its inlet (C, Fig C.2).
Figure C-1, Vacuum hose connections (exploded view).
1.5.3
Adding Oil to Oil Pump

TOOLS REQUIRED: 8mm hex wrench (not supplied).
The vacuum pump must be filled with oil to the correct level before it is switched on. Use an
8mm hex wrench to remove the oil filler plug (A, Fig C.2). Add oil to a level between the two
raised lines on the sight glass (B). Replace the oil filler plug. Make sure the ballast valve (D) is
closed (both “0” markings line-up).
A
C
Figure C-2, Oil Pump
D
B

NOTE! If you encounter any problems with the pump contact supportsp@anton-paar.com or local Quantachrome representative.
For vacuum pump maintenance see Appendix 7.2 in Section J.
15 of 158
Autosorb-6iSA/ASWin Operating Manual
1.6
D. SOFTWARE CONFIGURATION
Gas Connections

TOOLS REQUIRED: 7/16” wrench (not supplied).
The Autosorb-6iSA instrument has two gas input fittings, ADSORBATE and HELIUM, on the rear
panel. Helium must be connected for all measurements as the cell void volume is measured using
this gas at the start of each analysis.
Use high purity (99.995% or higher) helium and adsorbate gases. Attach a dual stage regulator
with stainless steel or Inconel diaphragm to the gas tanks. Connect the 1/8” copper gas input
lines (supplied) to the regulator and to the gas-input connections at the rear of the unit using the
nut & ferrule set supplied. It may be necessary to obtain an adapter in order to connect the tubing
to the regulator if it was not obtained from Quantachrome. A suitable regulator assembly
(P/N 193530) complete with shut-off valve, CGA580 cylinder fitting and 1/8” outlet fitting is
available from Quantachrome.
Set the pressure regulators to between 8 – 10 psig (55 – 69 kPa) on both adsorbate and helium
supplies.

NOTE! Do not use plastic gas lines anywhere between the gas cylinders and the
Autosorb-6iSA. These usually cause air to contaminate the gases which
then produces erroneous results. If the supplied gas lines are not long
enough, use only clean, metal gas lines similar to the ones provided.
!
CAUTION! Do not power up the Autosorb-6iSA for the first time until you have
installed the software and connected the instrument to the PC.
16 of 158
Autosorb-6iSA/ASWin Operating Manual
1.7
D. SOFTWARE CONFIGURATION
Instrument Overview
1.7.1
Autosorb-6iSA Front Panel Controls
MULTI-FUNCTION METER : displays manifold (MAN.) temperature (ºC), manifold pressure
(Torr), or sample station pressures (Torr).
•
There may be zero offsets on the meter when displaying pressure readings; these offsets
do not affect the operation of the Autosorb-6iSA.
•
The displayed values are not used by the instrument in any calculations (high-precision
values are used internally during the analyses).
See Figure C-4, Front panel of Autosorb-6iSA.
PUSHBUTTONS : select which reading displays on the meter.
See Figure C-4, Front panel of Autosorb-6iSA.
VALVE STATUS : indicated by two-color LED’s on the front panel which gives a complete
plumbing schematic of the Autosorb-6iSA.
•
A green light shows that a valve is open;
•
An amber light indicates a closed valve.
See Figure C-4, Front panel of Autosorb-6iSA.
DEWAR FLASK STATUS : indicated by 6 columns (one for each station) of three LED’s.
•
The top LED confirms the coolant level status for the sample station — a lit blue LED
indicates that the level sensor (HCLS/RTD) is in contact with coolant.
•
The middle LED indicates the intended direction of travel of the dewar platform — a lit
amber LED indicates that the platform has been instructed to move down, and conversely
an unlit amber LED means that the platform has been instructed to move up.
•
The bottom LED indicates whether the platform is static or in motion: a lit green LED
means that the platform is stopped in its intended up or down position, and an unlit green
LED indicates that the platform should be in motion.
See: Table C.3, Meaning of Dewar Status LEDs, Figure C-3, Dewar Flask Status LED Panel, and
Figure C-4, Front panel of Autosorb-6iSA.
17 of 158
Autosorb-6iSA/ASWin Operating Manual
D. SOFTWARE CONFIGURATION
Coolant Level Status:
A blue LED indicates
the level sensor is in
contact with coolant.
Direction of Dewar
Movement:
An amber LED
indicates that the dewar
is travelling down.
Dewar Status:
A green LED
indicates that the
dewar is not moving.
Figure C-3, Dewar Flask Status LED Panel
Table C.3, Meaning of Dewar Status LEDs.
Top
LED
Middle
LED
Bottom
LED
Meaning
○
○
○
Dewar is travelling up
●
○
●
Dewar is stopped and sensor is in
contact with coolant
○
●
○
Dewar is travelling down
○
●
●
Dewar is stopped in the fully down
position
18 of 158
Autosorb-6iSA/ASWin Operating Manual
D. SOFTWARE CONFIGURATION
MULTI-FUNCTION METER
PUSH BUTTONS
VALVE STATUS
DEWAR FLASK
STATUS
Figure C-4, Front panel of Autosorb-6iSA
19 of 158
Autosorb-6iSA/ASWin Operating Manual
D. SOFTWARE CONFIGURATION
Sample cell
bulkhead
BNC connector
P0 cell bulkhead
Sample cell
Coolant level
sensor
Dewar
shield
P0 cell
Dewar flask
for coolant
Figure C-5, Analysis station of Autosorb-6iSA
1.7.2
Analysis Stations
O-ring compression bulkhead fittings (see Section C.1.7.2.2) hold the sample cell during an
analysis. The coolant level sensor assembly connects immediately behind the sample cell fitting.
The sample cell and level sensor assembly hang in parallel. The P0 cell is connected to a
bulkhead fitting on the wall behind the cell. The coolant Dewar flask sits on a platform beneath
the cells and level sensor.
1.7.2.1
Sample Cells and Glass Filler Rods
Sample cells are available with outside stem diameters of 6, 9, and 12 mm (internal diameters of
4, 7, and 10 mm respectively). Each cell should be used with the appropriate glass filler rod.
1.7.2.2
Cell Bulkhead Fittings
The fittings for holding the sample cells use adapter sleeves and O-rings and are designed to
accept 6, 9, and 12 mm size cells (these dimensions refer to te outside diameter of the stem
portion of the cell). The correct size O-ring and adapter must be used with each corresponding
cell: see Figure C-6, Sample cell assembly and Ultra-Torr style fitting. Be sure to use only one
O-ring when installing a cell into the fitting; two O-rings (of any size) are likely to cause a leak
leading to erroneous results.
20 of 158
Autosorb-6iSA/ASWin Operating Manual
D. SOFTWARE CONFIGURATION
Figure C-6, Sample cell assembly and Ultra-Torr style fitting.
1.7.2.3
Dewar Flask
All Autosorb-6iSA instruments are supplied with custom Autosorb Dewar flasks (P/N 195451)
which are placed on their holders at the base of the lift-drives. The flasks hold the coolant,
usually liquid nitrogen, used for the analysis. The flasks should be filled prior to each analysis,
and when filled to the top they should hold LN2 for up to 60 hours. Orient the flask with the
handle toward you so the small rubber bumper lines up with the slot in the flask platform.
NOTE! Prior to the first use of the Dewar flask, the Dewar manufacturer
recommends the following:

•
•
Remove all the packing material from inside of the Dewar.
Wash the Dewar with hot, soapy water, rinse with distilled or de-ionized
water and either air dry or use a lint free towel.
Dewars must be completely dry before adding cryogenic (liquefied) gases.
1.7.2.4
Dewar Shield
Blue plastic covers are provided that reduce drafts around the sample cells thereby prolonging
coolant life and lessening frost buildup. They also afford protection against inadvertent cell
21 of 158
Autosorb-6iSA/ASWin Operating Manual
D. SOFTWARE CONFIGURATION
breakage. Slide the covers onto their retaining clips after you have installed both sample cells
and pre-filled dewars.
!
WARNING: Even though the Dewar shields afford some protection against broken
glass, always use eye protection when working around the Autosorb-6iSA. The
Autosorb-6iSA will still function automatically without the Dewar flasks in place.
!
CAUTION: When using the shields you must ensure the Dewar flasks are properly
oriented using the alignment slot at the rear of the holder. Otherwise, the Dewar
handle will impact the shield when it is raised by the lift-drive.
1.7.3
Right Side Panel
1.7.3.1
Calibration Chamber
The calibration chamber is used for manifold volume calibration (see Section F.1).
1.7.3.2
Vacuum Gauge
The vacuum gauge displays low pressure values. The gauge has two factory-set set points. The
lower set point is set approximately at 10mTorr and the upper set point is set at about 200mTorr.
The displayed values are not used by the instrument in any calculations.
1.7.4
Rear Panel
1.7.4.1
Mains Power Switches
The mains power switches are located at the rear of the Autosorb-6iSA. The switch on the right
controls only the electronics. The switch on the left powers the remainder of the instrument
including power to the vacuum pump socket. Move the switch lever(s) up ( | ) to turn on and
down () to turn off.
1.7.4.2
Power Select and UPS Socket
The electronics of the Autosorb-6iSA can be powered directly from the mains or via an
uninterruptable power supply (UPS). See C. 1.4 above.
1.7.4.3
USB Port
This USB port is used to connect the Autosorb-6iSA to a PC running ASWin software. It should
not be connected to any other computer or device.
1.7.4.4
Gas lines
There are two gas ports on the rear panel of the Autosorb-6iSA. There is one gas port for helium
and one gas port for the adsorbate gas.
22 of 158
Autosorb-6iSA/ASWin Operating Manual
1.7.4.5
D. SOFTWARE CONFIGURATION
Vacuum Pump Power Supply
The vacuum pump is powered through the Autosorb-6iSA and should be plugged into the outlet
on the rear panel labeled for the vacuum pump.
2
2.1
ASWin Software Installation
Connecting the PC to the Autosorb-6iSA
The minimum PC requirements are Windows XP or newer, a mouse, a keyboard, at least 12 MB
of available hard disk space, the USB Driver CD and a free USB serial port.
The proper cable and connectors are necessary to connect the PC to the Autosorb-6iSA. The
instrument is supplied with a 2m USB A/B cable. Follow the steps in the order as listed:
1 Ensure that the PC is working properly.
2 Install the USB Driver.
3 Connect the USB cable between the serial port at the rear of the Autosorb-6iSA and the PC.
4 Install the ASWin software on the PC, see Section C.2.2 below.

NOTE! Only after the software is installed should you power-on the
Autosorb-6iSA, see Section C.2.3, below.
2.2 Software Installation
ASWinTM software can be installed on any Windows-based PC (XP or newer). Ideally, make a
backup copy of the Installation CD before proceeding with the installation. Store the installation
CD and its backup copy in safe locations (preferably not the same place).
Install the ASWin software on the PC already running Windows ®following the steps below:
1
Insert the ASWin installation CD in your CD-ROM drive:
a) if auto-run is enabled, the startup menu will launch automatically
b) if not, open the CD-ROM drive in Explorer, and manually run the Setup (*.exe)
program.
ASWin launches the AS-MultiStation Setup Wizard which will prompt you through the
installation process.
23 of 158
Autosorb-6iSA/ASWin Operating Manual
D. SOFTWARE CONFIGURATION
Figure C-7, AS-Multistation Setup Wizard
The CFR version displays a “21 CFR-Part 11” banner across the bottom of the Version box.
a) Follow the prompts to specify: Installation type (Full, Upgrade, or Security Reset).
i. Full Installation: installs program files, sample data, and configuration
files. Also resets security and all configurations (materials, reports, etc.)
ii. Upgrade/Repair: installs program files only. Leaves all configurations
intact.
iii. Security Reset (affects only a previous installation of the CFR version):
resets passwords, security options, and user lists.
b) Install the Database feature. This feature allows you to search for analysis data files by
sample name etc. See the NOTE below for more important information regarding this
feature.
c) Additional Tasks. You can choose to have the Wizard create a desktop icon and/or a
Quick launch icon
2
An installation summary will be displayed (example below, Figure C-8). If you want to make
any changes, simply click the <Back button.
24 of 158
Autosorb-6iSA/ASWin Operating Manual
D. SOFTWARE CONFIGURATION
Figure C-8, Installation Summary
If you performed a Security Reset for a previously installed CFR version, the installation
summary will show only the CFR Security Reset.

3
NOTE! Do not install the CFR11 version over the regular version of the program,
and vice versa, without first uninstalling the other version.
Click Next> to start the actual installation. After installation is complete you have the option
to launch the program upon exiting the SetupWizard.

NOTE! In order to use the Database feature of the software, a version of the
Borland® DataBase Engine™ MUST be installed on the computer. If there is no
prior installation of this component (or you are not sure), choose the appropriate
option in the installation dialog, and it will automatically perform the installation.
Otherwise, (if prior installation eIists) it is optional to selIct it for upgrade
installation. Please contact Borland International for possible negative effects of the
upgrade on your existing products (www.borland.com).

NOTE! Vista / Win 7 users: For more details on ASWin installation, see J12.
25 of 158
Autosorb-6iSA/ASWin Operating Manual
D. SOFTWARE CONFIGURATION
2.3 Instrument Power Up
Ensure the communication cable is connected between the Autosorb-6iSA and the PC and that
ASWin software is running. Switch-on the MAINS power breaker at the rear of the instrument.
Then switch on the (adjacent) ELECTRONICS breaker. The software will display various
messages in the Autosorb Multistation Communicator. Depending on the status of your
instrument at boot-up, the messages may not exactly match the example shown below.
This is used in earlier
Autosorb 6B Kr/MP
models only. Expert
users can adjust the time
for helium removal
(done with Dewar down
after cold zone
Enter Y to perform leak
test of the manifold or N
to skip, then click Send.
Figure C-9, Instrument startup messages and leak test question.
Manifold Leak Test: Enter Y in the Reply box and click Send to perform the leak test or N to
skip it. If selected, the leak test will take 5 minutes or less. If no response is given, the leak test
will be bypassed and the startup completed.

NOTE! If the Autosorb-6iSA cannot reach the lower vacuum set point, the leak test
cannot be performed. If the <ENTER> key is pressed before the lower set point is
reached the screen will display the message: CANNOT REACH VACUUM.

NOTE! If, when starting the Autosorb-6iSA after a shut-down, the LED valve
status lights are not lit, the system is indicating a cell over-pressure situation and
will not initialize. Carefully remove each sample cell (or stainless steel slug) from
the sample stations one-by-one and allow the excess pressure to dissipate.
26 of 158
Autosorb-6iSA/ASWin Operating Manual
D. SOFTWARE CONFIGURATION
D. SOFTWARE CONFIGURATION
Before using the Autosorb-6iSA for the first time, you should familiarize yourself with the
software. It is based on the common Windows application interface and you should have no
difficulty navigating around it. Any special keys or actions will be clearly highlighted in the text
below. ASWin displays a menu bar across the top of the main window that allows access to data
files, instrument operation, and other settings. Each menu choice is described below.

1
1.1
NOTE! If you need more information or assistance using a particular software
feature, simply access the detailed help file from the main menu, or the “?” help
button in most of the dialog boxes, or simply press F1 on your keyboard.
Initial Launching of ASWin Software
Non-CFR version
When the non-CFR ASWin software version is installed and launched the User Selection
window pops-up prompting the user to enter User ID. This ID will appear in the report header in
the “Operator” fields.
1.1.1
User Login
To login, enter User ID of your choice and click OK. If you wish to automatically login as the
same user each time the program starts, check the Autologin with this ID box:
Figure D-1, Enter user ID.
27 of 158
Autosorb-6iSA/ASWin Operating Manual
1.1.2
D. SOFTWARE CONFIGURATION
Changing User
Click here to
change the User
Figure D-2, Changing user when ASWin is running.
The new login window will appear (see Figure D-1). Enter a user ID. You may also choose to
Autologin, as described in Section D.1.1.1.
1.2
1.2.1
CFR Version
Initial Security Configuration
When the CFR version of ASWin software is launched for the first time after installation, the
user will be prompted to Configure Security features:
Select desired security
level; if None is
checked, NO Security
limits will be set.
Select desired options
by checking/unchecking the boxes.
Scroll up or down to
change.
Figure D-3, Selecting desired security level.
28 of 158
Autosorb-6iSA/ASWin Operating Manual
D. SOFTWARE CONFIGURATION

NOTE! Before clicking on <OK> button, which will irreversibly finalize the
security set-up, you should verify that selected options are the ones
desirable for the software operation. Once the security options are accepted,
they cannot be changed. In order to reset the security settings, the software
needs to be re-installed (see Section C.2.2) and all user accounts re-created
(see Section D.2.3).

NOTE! Security settings are only applicable for the CFR version of the ASWin
software.
Select Full Security Level to enable all of the security features of ASWin including required
login, full audit trail for any changes to data files, the ability to print audits, and software timeout
due to user inactivity.

NOTE! You must select Full Security Level for the software to operate within the
guidelines of 21 CFR-Part 11.
Selecting Custom Security Level will allow you to choose which security features you wish to
incorporate. Check the boxes next to the security action you wish to have enabled.
Selecting None for Security Level will disable all security features.
The following security features can be selected at installation time:
Login required
requires user identification before using the system
Audit changes
tracks changes made to the data
Print Audit
prints change history with each document
Auto re-login
prevents unattended workstations to be used by unauthorized users
Password aging
enforces password changes in pre-defined periods
Password retention
remembers a pre-configured number of previous passwords and
prevents re-use
The following security features are always active:
Report integrity check allows verification of report printout integrity
System security log
maintains a list of all relevant security events
Minimum ID length
forces user ID and password minimum length (six by default)

NOTE! Once a given Security Level is selected, it cannot be changed for a given
installation. If you wish to change the Security Level, you must run the
installation wizard from the CD again and select Reset Security. All user
accounts and security settings will need to be setup again.
29 of 158
Autosorb-6iSA/ASWin Operating Manual
1.2.2
D. SOFTWARE CONFIGURATION
Creating Superuser Account
After the security level for the software is configured, you must create a Superuser account (the
User Properties window will pop-up). Only a Superuser has full control of the system,
including defining and managing user accounts. After the security level has been configured,
the User Properties screen will appear. Enter desired User ID and a Password (both are casesensitive and must have the minimum length specified on the Configure Security window). Retype the Password in the Confirm Password box.
Enter info for the
Superuser Account: ID
and Password (case
sensitive), Name, etc.
Click OK to
create the
Superuser
Account.
Figure D-4, Creating a Superuser account.
Finally, enter the full name of the user in the space provided (in the example above, Frances
Superuser was used as a full name). An entry in the Comment box is optional. If all of the
required fields in the User Properties box have been filled-in correctly, the OK button will
become active. Click on OK button when you are finished.
1.2.3
Login
Immediately after the Superuser Account is created, the login window will appear.
To login, enter correct User ID and Password combination and click on Login button:
Figure D-5, Logging into the ASWin system.

NOTE! User ID and Password are case sensitive, make sure Caps Lock is off.
User will have 4 chances to login.
If the user ID and/or Password entered are incorrect, the following error message will display:
30 of 158
Autosorb-6iSA/ASWin Operating Manual
D. SOFTWARE CONFIGURATION
Figure D-6, Invalid login message.

NOTE! You have four chances to enter a correct User ID/Password combination.
The software will automatically disable given User Account after the
System Login fails fourth time in succession. Only the Superuser can reenable disabled user account. See D 2.5
If the attempt to login fails four consecutive times due to incorrect ID/Password combination, the
program records the failed login attempt in the system log and against the User account:
Figure D-7, User account disabled flag.

NOTE! Only the System Supervisor (Superuser) can re-enable disabled accounts.
Therefore, if the only existing Superuser account is disabled, the ASWin
CFR software will have to be re-installed and User accounts recreated.
After a successful login, the Superuser account can:
1. Proceed with instrument settings/operation.
2. Create and manage additional accounts with customized levels of privileges (Superuser
– administrator user with the highest control level; Manager – user with moderate
control level; Operator –limited user, allowed only to upload and run preconfigured
analyses). For details on how to create/manage User Accounts, see Section D.2.3.
31 of 158
Autosorb-6iSA/ASWin Operating Manual
1.2.4
D. SOFTWARE CONFIGURATION
Re-Login
After a specified (during initial configuration) time of account inactivity (by default, after 15
minutes) the current user will be automatically logged-out and the system login screen will popup with User’s ID grayed out. To re-login, enter the password then click Login, or click Exit to
close the program.
Figure D-8, Re-logging in after automatic logout.

NOTE! User ID and Password are case sensitive, make sure Caps Lock is off.
User will have 4 chances to login.

NOTE! If the Security Level: None was selected when installing ASWin CFR
software version, all security features will be disabled and user login will
proceed as described in Section D.1.1.
2
ASWin Menu System
The ASWin program uses a standard Windows style interface consisting of menus, buttons, and
various dialog windows. The main menu bar contains six drop-down menus providing access to
operations and procedures of the program:
Main Menu bar
Name of Currently
Logged-in User
Toolbar
Figure D-9, Status bar information.
32 of 158
Autosorb-6iSA/ASWin Operating Manual
D. SOFTWARE CONFIGURATION

NOTE! When any data file is open the Floating Menu is also accessible; see
Section G.4 Floating Menu.

NOTE! CFR Version: Depending on the Security Configuration and User Level
the available (active) Main Menu options will slightly vary.
2.1
Main Menu — No Security
In the case of non-CFR software version or CFR version when None security level was selected
during initial launch, the Configure tab in Main Menu will not include any security options
(user access levels, passwords, etc.). All users will have all privileges to access all menu options.
Figure D-10, Main menu options with no security installed.
33 of 158
Autosorb-6iSA/ASWin Operating Manual
D. SOFTWARE CONFIGURATION
2.2 Main Menu — Security Access Levels
ASWin CFR version has three Access Levels: Superuser, Manager, and Operator:
Superuser — users in this level have full control of the system, including
defining and managing user accounts.
Manager — users in this level are allowed to change most of the
configuration options, but cannot change user assignments.
Operator — users of this level are allowed to operate the software; however,
they are prohibited from changing most of the configuration
options.
Throughout this manual, the following symbols will be used to denote which level user has
access to the features of the ASWin software:
Superuser
level
Manager
level
Operator
level
Figure D-11, Symbols indicating which level user has access to described feature.
Symbols with an X marked through S/M/O denote that the feature is not accessible for users at
that security level.
Each user account is assigned a level of access at time of creation. The Access Level can be
changed only by Superuser level administrators through the User Manager window.
34 of 158
Autosorb-6iSA/ASWin Operating Manual
2.2.3
D. SOFTWARE CONFIGURATION
Main Menu Options – Superuser Level
As the most privileged level, Superuser has expanded Security Options in
Main Menu>>Configure tab:
Figure D-12, Main menu and submenus at Superuser level.
Users in this level have full control of the system, including access to Manual Mode, defining
and managing user accounts, etc.
2.2.4
Main Menu Options – Manager Level
Users with Manager access level have fewer priveleges than those with Superuser access level.
Managers are allowed to change most of the configuration options, but cannot change user
assignments; therefore, their available Security Options in Main Menu/Configure tab are limited
to changing their own password.
2.2.5
Main Menu Options – Operator Level
Users with Operator access level have the fewest privileges; they are allowed to operate the
software, but are forbidden to change most of the configuration options (disabled options in File,
Configure and Operation tabs are grayed-out):
35 of 158
Autosorb-6iSA/ASWin Operating Manual
D. SOFTWARE CONFIGURATION
2.3 Assigning Access Levels to New Users
After login as the Superuser first click Security on the Configure menu and then User Manager
Figure D-13, Accessing the User manager.
The Properties and
Delete buttons are
active (un-grayed)
only when a User ID
is highlighted.
Figure D-14, User manager window.
To add (create) a new user, click on New or press <N>) to open the User properties window:
Enter required information
into fields provided (User
ID, Password, Confirm
Password, Full Name).
Select desired
Access Level from
the drop-down list.
Click OK to
add this user.
Figure D-15, Adding a new user through User properties.
36 of 158
Autosorb-6iSA/ASWin Operating Manual
D. SOFTWARE CONFIGURATION
The newly added user will appear on the users list:
Figure D-16, Viewing the users list.
2.4 Reviewing/Editing User Properties
Superuser can review/change the properties of other users (of lower privileges) such as: access
level, password, description, comments. To edit, highlight the name and click on Properties:
Figure D-17, Editing users through
User manager.
Figure D-18, Editing user properties.
37 of 158
Autosorb-6iSA/ASWin Operating Manual
D. SOFTWARE CONFIGURATION
2.5 Disabling/Enabling Users
At any time, Superuser can disable/enable lower-level users (Manager, Operator) by
checking/un-checking the Account Disabled box, respectively:
If this box is checked,
user will be disabled
Figure D-19, Disabling users as a Super User.
Disabled user will not be able to log in until the Superuser re-enables the account (by unchecking Account disabled box in User properties window).
Similarly, when the account is disabled due to login failure (multiple invalid ID/Password
combination), user will not be able to log in until the Superuser re-enables the account (by unchecking Account disabled box in User properties window):
Message with lockout details will
display
Un-check this box
to re-enable user
account
Figure D-20, Re-enabling a user.

NOTE! If there is only one account with Superuser level and it becomes disabled,
the ASwin CFR version software has to be uninstalled and re-installed; all
security features/user accounts will have to be reconfigured/recreated.
38 of 158
Autosorb-6iSA/ASWin Operating Manual
D. SOFTWARE CONFIGURATION
2.6 Changing (your own) Password
Click Security on the Configure menu and then click Change Password. This
will open the system login window:
►
Figure D-21, ASiQwin system login.
Enter your USER ID and current password, click Login and in the next window enter a new
password, confirm, and click OK.
Figure D-22, Setting a new password.
The new password must be different from the last n passwords, where n is the number of
passwords remembered by the program.
3
Communication Setup
The Operation bar on the Main Menu contains operation options for the instrument connected to
the serial port of the PC. To change communication settings for ASWin, click Instrument
Settings:
Click here to open
Instrument Settings
window and configure the
serial port, instrument’s
model/type, and gas ports
Figure D-23, Configuring instrument settings.
39 of 158
Autosorb-6iSA/ASWin Operating Manual
D. SOFTWARE CONFIGURATION
This will open the Instrument Settings window:
Select instrument model
(Autosorb-3 is a legacy model)
Make sure the correct
RS232 communication
serial port is selected
Select “Anygas”.
Krypton/Micropore is
legacy Autosorb-6B type.
Check to reset
Autosorb when
OK is clicked
Check if instrument is
capable of initial fill
(legacy Autosorb-6BKr/MP only)
Figure D-24, Setting up instrument settings.
Here, you can select the serial port to be used, and the appropriate instrument model. It is crucial
that these options are set correctly, otherwise communication problems may arise.
Select the communication port using the drop-down list to specify the port to which the
instrument is connected. If the port is changed, the instrument will automatically restart the
communication protocol when exiting the dialog by clicking the OK button. If no change was
made to the port setting, check the Force reset on OK checkbox to restart it anyway.
Specify the Instrument Model by checking the Autosorb-6 button for the Autosorb-6iSA (and
legacy Autosorb-6B), check Autosorb-3 for legacy Autosorb-3B model. Check “Anygas” as the
instrument Type (Krypton/Micropore must not be checked unless your instrument is a legacy
Autosorb-6B-Kr/MP or Autosorb-3B-Kr/MP).
Click OK to save the configuration (and restart communication as described above), or Cancel
to discard any changes you made.
4
Configure Options
4.1 Manage Materials: Edit Adsorbate Parameters

NOTE! Users at the Operator level can view these parameters but cannot change
them.
40 of 158
Autosorb-6iSA/ASWin Operating Manual
D. SOFTWARE CONFIGURATION
To view or modify the adsorbate model parameters, click Manage Materials on the Configure
menu then Adsorbates:
Figure D-25, Editing the adsorbate parameters.
Click the Name button (►) and select the adsorbate from the dropdown list. The current values
for these adsorbate model parameters will be displayed. Parameters for several often-used
adsorbates are predefined in the ASWin software and these parameters cannot be changed; their
entry fields are grayed out.
To modify the model parameters for the predefined adsorbate, click Copy and give a new name
to the adsorbate model.
Figure D-26, Entering a new adsorbate name.
Click OK and the new window with active parameter fields will appear.
41 of 158
Autosorb-6iSA/ASWin Operating Manual
D. SOFTWARE CONFIGURATION
Figure D-27, Setting parameters for a new adsorbate.
Click on the Advanced tab to view more parameters. Modify the parameter values as you wish
and click Save to store the new model parameters assigned to the new adsorbate name in the
appropriate model database.
To create a new model, click New and follow the steps described above. The Adsorbate
Parameters window will have all fields filled with zeros which you will need to replace with
appropriate values.
To delete an existing model, select it from the list, and then click Delete. Note that predefined
models cannot be deleted; the Delete button is disabled for these models.
The delete operation is not reversible — once a model is deleted, it cannot be restored.
Click Close to leave the window and return to the main program. If you have not saved changes
at this time, you will be prompted to do so.

NOTE! The Name of the adsorbate represents the model adsorbate defined by the
set of model Adsorbate Parameters. One adsorbate may have several
Names representing different sets of Adsorbate Parameters. For example,
if an adsorbate is used at several temperatures some of its parameters will be
different for different temperatures.
42 of 158
Autosorb-6iSA/ASWin Operating Manual
D. SOFTWARE CONFIGURATION
4.2 Manage Materials: Edit Adsorbent Parameters

NOTE! Users at the Operator level can view these parameters but cannot change
them.
To view or modify the adsorbent model parameters, click Manage Materials on the Configure
menu then on Adsorbents:
Figure D-28, Editing adsorbent parameters.
There are two predefined adsorbent models in the ASWin software: Carbon and Oxygen/Zeolite.
To modify or add new models, follow the steps analogous to those described above for editing
adsorbate parameters.
4.3 Edit Data Reduction Parameters (DRP)

NOTE! Users at the Operator level can view these parameters but cannot change
them.
Click Edit Data Reduction Parameters on the Configure menu to view and modify the
parameters. For details on setting DRP see Section G.7. This DRP option allows the user to
manage, create, or modify pre-defined DRP sets. By default, the DRP set has no bearing on the
operation of the software. The exception is: once a default.DRP file is created, it is automatically
loaded when a new file is created (e.g. importing data from non-native formats). To change the
DRP set of an existing data file, access this dialog from the context menu of any graphical or
tabular view of the data file.
After you edit a DRP set, you can save it as a new file for later use in the progr’m's Config
folder.
43 of 158
Autosorb-6iSA/ASWin Operating Manual
D. SOFTWARE CONFIGURATION
4.4 Set Data Folders
The software allows predefined default folder settings for each data file type it
recognizes. Use this configuration window to specify the default location of the selected file
type:
Click Select Path to
browse or create a
new folder for the
selected file type.
Figure D-29, Selecting locations of data folders.
Whenever a file of these types is being opened or saved, the file selector dialog starts in the
specified folder. The list entries on the top of the window display the current path setting for
each folder recognized by the software.
To change the default location, click on Select Path, or double click on an item in the list, and
using the standard Windows type folder locator dialog, navigate to the desired folder, and then
click on the Select button.
Each entry in the list is prefixed with one of the following icons:
The folder selection
for this entry is
correct and usable.
Figure D-30, Legend for folder selection.
The currently logged user
has insufficient rights.
Each user operating he
software must have full
access (i.e. to read, write
and modify) to all of these
folders. You may need
assistance from your
system administrator
The selected folder for this entry does not
exist. Select the entry, and Select Path to
select or create a different one.
44 of 158
Autosorb-6iSA/ASWin Operating Manual
D. SOFTWARE CONFIGURATION
Clicking Cancel closes this window without saving the changes and OK will save them. The OK
button is grayed out when there is any problem in the list.

NOTE! If this window is invoked automatically upon starting the software it
indicates that the software found problems with some of the folder
definitions. In this case, closing the window with the Cancel button will exit
the software as well..
If there are problems, and the current user is below management level, a message window pops
up describing the problem, and requesting that a higher level user be logged in to correct the
indicated problems.
45 of 158
Autosorb-6iSA/ASWin Operating Manual
E. SAMPLE PREPARATION
E. SAMPLE PREPARATION
Before analysis every sample should be properly degassed by flow or vacuum to remove surface
adsorbed gases and vapors, primarily water molecules. Sample preparation for physisorption
measurements involves the optimization of several key variables including:
• Sample cell selection
• Vacuum or flow
• Degas temperature selection
• Degas time
• Unloading sample cell / use of backfill gas
• Minimization of elutriation
1
Sample Cell Selection
Two factors to consider when selecting a sample cell are stem diameter and sample amount /
sample bulb size.
Stem diameter: Choose the narrowest diameter cell that will comfortably admit the sample. For
example, a fine powder should be analyzed in a 6 mm outer diameter (o.d.) (4 mm i.d stem cell).
Use the 12 mm o.d. stem cells for large pieces that cannot be reduced in size. Larger particles
such as granules, and small pellets might require a 9 mm o.d. (7 mm i.d.) diameter stem. Of
course, cohesive powders may be analyzed in 9 or 12 mm stem cells to facilitate addition,
removal, and cleaning.
Sample amount / Bulb size: Always use the smallest bulb that will accommodate the optimal
amount of surface area (unless elutriation is an issue: see section 4 below). Larger total surface
areas can certainly be analyzed, but they may lengthen the analysis. For surface area
determinations only, sample amounts from at least 1 m2 to 5 m2 can be analyzed using nitrogen,
but careful consideration should be given to proper degassing and equilibrium criteria. Full
adsorption and desorption isotherms should have at least 10 – 20 m2 in the cell.
Wider stems and larger bulbs can be beneficial in reducing elutriation, see Section D4.
2
Methods of Sample Preparation
Samples can be degassed under vacuum or a flow of dry inert purge gas (usually nitrogen).
Vacuum is often preferred since evolved water molecules can more easily diffuse out of small
pores in the absence of an inert purge gas. However flow degassing can quickly remove larger
amounts of water if the samples have not been pre-dried.
Quantachrome provides a range of suitable Degassers for proper sample preparation. The use of
the XeriPrep Degasser (vacuum method) is recommended, but the MasterPrep, FloVac and Flow
Degassers can all be employed. Some differences can arise between degassing under vacuum
(XeriPrep Degasser, Autosorb Degasser, MasterPrep, FloVac) and degassing under a flow of
inert gas (MasterPrep, FloVac, Flow Degassers)
46 of 158
Autosorb-6iSA/ASWin Operating Manual
3
E. SAMPLE PREPARATION
Choice of Degas Temperature and Degassing Time
Samples should be degassed at the highest temperature (up to 350°C) that will not cause a
structural change to the sample. This will accelerate the degassing process. For instance, most
carbon samples can be degassed at 300°C, as can calcium carbonate. Many hydroxides must be
degassed at a lower temperature. Degassing organics and metal organic frameworks (MOF) must
be performed with care since most have quite low softening or glass transition points, or may
undergo structural transitions at higher temperatures. For example, magnesium stearate, a
common pharmaceutical excipient, should be degassed at 40°C according to the USP. Loosely
bound physisorbed water will be lost at relatively low temperatures under the influence of
vacuum, but strongly bound surface water might require high temperatures. Many zeolites, for
example, will retain significant quantities of water in their micropores up to 400 °C.Use standard
methods such as those published by ASTM, DIN, ISO, etc. to guide your selection of an
appropriate degassing temperature.
If you have access to thermal analysis equipment, especially gravimetric, conduct an analysis on
a separate aliquot of material prior to degassing an aliquot for analysis on the Autosorb-6iSA. A
suitable degassing temperature would lies in a plateau, or weight-stable region, of the
thermogram. Ideally, the thermal analysis should be conducted the same atmosphere conditions
as for degassing, i.e. vacuum or flow. In general, too low a degassing temperature will cause
lengthy preparation, and may result in lower than expected surface areas and pore volumes.
Too high a temperature can cause irreversible damage to the sample, which can result in a
decrease in surface area due to sintering, or an increase in surface area due to a thermally
induced decomposition.
Time for complete degassing, that is complete removal of unwanted vapors and gases adsorbed
on the sample surface, can only be properly determined by conducting a series of tests to
determine those conditions of temperature and time which yield reproducible data. As a general
guideline however, three hours (at temperature) should be considered a reasonable minimum.
IUPAC often recommends no less than sixteen hours, which can be conveniently achieved
overnight. Samples that require low temperatures generally require the longest outgas times.
However, the USP recommended degassing period for magnesium stearate is just two hours at
40°C.
A sample degassed under vacuum can be considered ready for analysis when the sample passes a
degas pressure-rise test of no more than 50 mTorr/min at elevated temperature. A sample that
cannot pass the same criterion at room temperature may not be able to be initialized by the
Autosorb when installed in the analysis station. Remember, the Autosorb must be able to pull,
and hold, a high vacuum in the sample cell in the presence of sample. A contaminated degas
station may give artificially high degassing rates during test. You can establish the background
47 of 158
Autosorb-6iSA/ASWin Operating Manual
E. SAMPLE PREPARATION
pressure rise of a degas station by “loading” and “testing” a dowel pin or clean and empty
sample cell. A clean system should be able to pass a 20 mTorr/min test.
4
Elutriation and Its Prevention (Vacuum Degassing)
Elutriation, or loss of powder out of the sample cell, is caused by too rapid a gas flow out of the
cell. It is most problematical for low-density samples, fumed silica for example.
Wider stems and larger bulbs can be beneficial in reducing elutriation. Wider stems reduce the
velocity of the gas leaving the cell when evacuation begins and thus it is less likely to entrain
powder particles and transport them upwards and out of the cell. The presence of a filler rod
significantly increases gas velocity because of the narrowing of the internal dimensions and can
exacerbate elutriation. In problematical cases, the filler rod may be dispensed with during
analysis, but some loss of resolution and/or sensitivity may result.
The most dramatic elutriation problems are encountered during degassing of damp, “light”
powders. As the sample heats from ambient, the pressure over the sample decreases due to the
action of the vacuum. At some point, the water “flashes” into steam. This rapid expansion of gas
volume drives powder out of the bulb and up the stem of the cell. This condition can be reduced
or eliminated by (i) pre-drying the samples in a conventional drying oven and degassing under
just vacuum or (ii) raising the temperature of the heating mantle in 20 degree steps. It is
recommended that the temperature be “paused” at 60 °C for 30 – 60 minutes under vacuum to
allow for a milder removal of moisture before increasing the temperature to 80 °C, then 100 °C
and finally maximum degas temperature, or (iii) using the Cell-Seal (see note below).
A further flow restriction is obtained with a tight fitting 20 micron filter. The filters are available
in Non Elutriating Cell Kits, P/N 193696 (6 mm large bulb), 196460 (6 mm straight long),
193697 (9 mm large bulb), and 193705 (9 mm straight long).
The Cell-Seal (see NOTE below) also blocks the elutriation of fine powders.
In the most difficult cases, and the aforementioned methods have not eliminated the problem it
might be necessary to insert a small glass wool plug into the cell stem. This can be held in place
between two halves of a cut-in-two glass filler rod. This is the only time that a filler rod should
be used in the degasser.
5
Choice of Backfill Gas (Vacuum Degassing)
Preferably, the adsorbate (nitrogen) should be used as backfill gas to prevent or minimize
buoyancy errors. A sample cell will weigh less when filled with helium than when filled with air
or nitrogen. The error introduced is approximately 1 mg per mL of cell volume. This can be
significant when using extremely small sample weights (< 50mg).
48 of 158
Autosorb-6iSA/ASWin Operating Manual

6
E. SAMPLE PREPARATION
NOTE! The Cell-Seal prevents the exposure of air and moisture-sensitive materials
during the transfer of the sample cells between degas and analysis ports by
automatically closing off cells. A built-in 20 micron metal frit filter blocks
the elutriation of fine powders into the instrument port, and a self-sealing,
spring-loaded valve with actuator opens the valve when the sample cell is
inserted into the station. The Cell-Seal is available in two sizes: 9mm
(P/N 222935) and 12mm (P/N 222959) is sold individually, not as part of a
complete kit including sample cells. Refer to Cell-Seal Usage for more
information.
Flow Degassing
Nitrogen gas is preferred as it will not introduce any buoyancy errors as would helium. The flow
rate should not be so high as to cause a major disturbance to the bed of sample. Too high a flow
rate will elutriate powders out of the cell. The flow tube should be 2-5mm from the surface of the
sample. Always avoid having the flow tube touch the sample.
7
Cooling the Sample Cell
Samples should be completely cooled to room temperature before weighing and analysis. You
can choose to cool the samples on the degasser (under vacuum or backfilled with gas, or under
continued flow of dry purge gas). If you not are ready to weigh analyze a sample immediately it
has cooled, you can cap the sample cell with a plastic plug P/N 193680) that fits 6mm, 9mm and
12mm diameter cell stems – except 9mm cells employing the non-elutriation filter. The Cell-Seal
(see NOTE above) will also temporarily seal the sample cell until installed on the analyzer.
!
CAUTION! Do not use cracked or chipped sample cells.
49 of 158
Autosorb-6iSA/ASWin Operating Manual
F. INSTRUMENT OPERATION
F. INSTRUMENT OPERATION
1
Manifold Calibration (infrequent)
All the results obtained on the Autosorb-6iSA are based on the volume of the dosing manifold
which is factory calibrated. You should perform this calibration only if changes to the system
(such as valve or transducer replacement) have been made, or periodically as mandated by your
quality assurance group.

NOTE! There is no need to perform a manifold calibration on a regular basis and
certainly not before every analysis.
The manifold cannot be calibrated while a sample is running or degassing.
The Autosorb-6iSA uses a calibrated sphere in the calibration chamber on the right side of the
instrument for calibration. To calibrate with a calibration sphere, first, ensure the sphere is not in
the calibration chamber. Fully seat the cover with its white fiduciary marks aligned and close
tightly.
To calibrate the manifold, go to the Operation menu and click on Calibrate Instrument. Select
Calibration Command by typing the corresponding number in the Reply box and clicking Send
button (See Figure F-1).
If the manifold calibration is already known, and you simply need to re-enter the values for
example after replacing the CPU board, option 2 or 3 may be selected and the appropriate values
entered. Enter 4 to abort without changing anything. To calibrate the manifold, enter 1 in the
Reply box and click Send.
A series of messages are displayed in the window and when a stable pressure is achieved, you
will be prompted to place the calibration sphere in the chamber (see Figure F-2). Open the
chamber, insert the calibration sphere, line up the white fiduciary marks, and tighten the cap.
When ready, hit the <Enter> key on the keyboard (do not type RETURN in the Reply box).
Another series of messages will be displayed. Follow the instructions on the screen and when the
calibration is complete, you will have the choice to save the new calibration, use the previous
calibration, or enter a specific value.
50 of 158
Autosorb-6iSA/ASWin Operating Manual
F. INSTRUMENT OPERATION
Figure F-1, Menu for manifold calibrations.
Figure F-2, Insert sphere and hit Enter key to continue.
2
Void Volume Determination (automatic every analysis)
The Autosorb-6iSA uses helium to measure the void volume of each sample cell at the beginning
of an analysis. The void volume is determined by expanding a known quantity of helium (based
on the volume and temperature of the dosing manifold and the pressure of helium gas) into the
sample cell at ambient temperature and calculating the total volume from the pressure change.
The cell is then cooled and the “cold zone” volume calculated from the pressure drop. Helium is
51 of 158
Autosorb-6iSA/ASWin Operating Manual
F. INSTRUMENT OPERATION
used for this procedure as it is not adsorbed by the sample at liquid nitrogen temperature, unlike
the adsorbate. The “warm zone” volume is the difference between total and cold zone volumes.
3
Sample Analysis Setup
To perform analysis of a sample with a given adsorptive, attach the Po cell and the appropriate
coolant level sensor (HCLS/RTD) to one of the analysis stations (see Section C.1.7). Attach the
sample cell with the outgassed sample (for details on sample preparation, see Section E) to an
unused station, and place a dewar flask (see Section F. ) containing the appropriate coolant on
the Dewar platform (making sure to align the rubber bumper on the Dewar with the slot on the
platform).
Analysing samples requires the proper setting of several parameters that describe methods and
conditions for the measurements (Po determination, data point selection, and equilibrium
conditions) in addition to sample information.
To enter both sample and measurement parameters for the analysis, click Start Analysis on the
Operation menu to open this window:
Click on each tab to review and edit
sample-specific information,
measurement parameters, data points
to be acquired, and calculation &
reporting options
Click on the station tabs to
open the setup screens for
each individual sample
Prior to starting, check each box
of those stations to be run
Figure F-3, Start Analysis window.
52 of 158
Autosorb-6iSA/ASWin Operating Manual
The
Start
Analysis
window
F. INSTRUMENT OPERATION
uses
tabbed
segments
(see
Figure F-3). The tabs near the bottom of the window select the parameter input forms for each of
the six analysis stations.The four tabs at the top of the page access all available parameters for
review/edit for the station selected by the bottom tab. The parameters accessed by the top tabs
are grouped by functionality, Admin, Analysis, Points, Data Reduction, as described below.
3.1
Sample Parameters (Admin)
Click on the Admin tab to enter the sample’s information: name and description, weight (in
grams), outgas temperature and time, and to set/verify the analysis file name.
Operator ID:
The operator ID is displayed here for verification, since it will be stored
with the acquisition data. It can only be changed via the
File>>Logoff/login menu option (see Section F. ).
File Name:
Enter the name of the data file to be created here. Use any valid filename
characters. Do not enter path or extension information here; they will be
automatically generated. Click the Verify button to see what the resulting
filename would be given to this file for the above-entered name. The full
filename including path and extension will be displayed. A filename is
mandatory.
In order to automate and unify the file naming, the software allows the use of special macro
characters to be included in the filename template. This helps to maintain file naming
conventions throughout a lab, and (when used correctly) prevents file name conflicts.
53 of 158
Autosorb-6iSA/ASWin Operating Manual
F. INSTRUMENT OPERATION
To automatically generate unique filenames for each run you can use special characters $ and #.
The Filename macro will replace these characters by digits according to the following scheme:
Date: $
Up to 8 “$” characters can be embedded into the filename template.
Upon analysis start, the system will format the current date into
YYYYMMDD format, and will replace each “$” (from right to left) with
the appropriate character from the date string.
Example: on August 19, 2008, the filename template: $$$$_$$_$$ will
expand to 2008_08_19. On the same day the template: $$_$$$$ will
expand to 08_0819.
Serial Number: #
Up to 4 “#” characters can be embedded into the filename template. Upon
analysis start, the system will generate an integer serial number with the
number of digits matching the number of “#-s” in the macro. This index
starts at 0 and is incremented until an unused filename is found. Then the
“#-s” are replaced (from right to left) with the corresponding digit of the
index.
Example: on consecutive runs, the filename template: data_##_## will
expand to data_00_00, data_00_01, data_00_02..., and so on. The upper
limit is determined by the number of #-s.
Station Number: <STN> The macro <STN> will be replaced with the station number on which
the data are acquired. E.g. the template ASMS_ST<STN>_## will expand
to ASMS_ST1_01.qps on station 1 and AS6_ST5_01.qps on station 5.

NOTE! When creating parameter sets in the CFR version, the above macro
characters should be used to automatically generate unique filenames, since
a user at Operator level is not allowed to modify the filename.
Figure F-4, Expansion of sample file template.

NOTE! Due to limitations of the data stream between the instrument and the
software, the expanded filename cannot exceed 80 characters.
54 of 158
Autosorb-6iSA/ASWin Operating Manual
F. INSTRUMENT OPERATION
Comment:
If desired, enter any comments specific to the analysis in this field (not
mandatory to initiate an analysis).
Sample:
ID (not mandatory): Enter the unique sample identification in this field
Description (not mandatory): Describe your sample in more detail here
Weight (a non-zero value is mandatory): Enter the mass of the sample, in grams.
Outgas Time (not mandatory): Enter the degassing time, in hours.
Outgas Temp (not mandatory): Enter the degassing temperature, in °C.
Any
positive,
non-zero
value
Any
positive
value (zero
is OK)
Accepts up to 50 alphanumeric
characters
Accepts up to 50
alphanumeric
characters
Check
those
stations
you want
to start
Any value
greater
than
-273.16
3.2 Analysis Parameters
Click the Analysis tab to select and set measurement parameters for the analysis on the specified
station:
55 of 158
Autosorb-6iSA/ASWin Operating Manual
F. INSTRUMENT OPERATION
Each station has its
own Admin, Analysis,
Points and Data
Reduction settings
Figure F-5, Analysis (parameters) tab.
3.2.1
Adsorbate
Click the Adsorbate button () to select the adsorbate gas from the drop-down list.
Figure F-6, Select adsorbate.

NOTE! Only one adsorbate can be connected to the Autosorb-6iSA at one time, so
ensure that all stations have the same adsorbate name selected.
If you don’t see the adsorbate you want to use, you can add your own by using the Edit
Adsorbates function in the Configuration menu, see D. 4.1.
!
CAUTION! Some adsorbates (other than those in the default list above) may be
incompatible with the instrument. Only non-corrosive gases compatible
with materials of construction (glass, copper, stainless-steel, Buna and
EPDM) may be used with Autosorb-6iSA.
56 of 158
Autosorb-6iSA/ASWin Operating Manual
3.2.2
F. INSTRUMENT OPERATION
Adsorbate Parameters
Predefined Adsorbates have their default adsorbate parameters automatically inserted in the
necessary fields (e.g. non-ideality). However, you can change these parameters depending on the
type of adsorbate and temperature used. Changes to these parameters should only be done by
expert users. If in doubt, please contact support-sp@anton-paar.com.
3.2.3
Evacuation
If the sample is a fine powder (that might elutriate if the system is evacuated rapidly) select Fine
to evacuate slowly. Select Coarse to evacuate quickly, for example when running pellets or
heavy granular samples.
3.2.4
Initial Fill
This option can be used to reduce the time taken to fill micropores by “pre-loading” a volume of
adsorptive to initially overcome the extended time it takes to add enough adsorptive to reach the
desired first target relative pressure. Check this box to enable this option. The Fill Volume
entered must be in range 0.01–100cc. The equilibration time (see 3.4.7) for the first datum point
should be extended to 5 or more to compensate for the large amount of gas dosed
3.2.5
MaxiDose enabled
When this option is enabled, an intelligent dosing algorithm is implemented. If the pressure falls
below the allowed pressure tolerance, the algorithm will automatically increase the volume of the
dose. In this manner, successively larger doses of gas are admitted into the sample cell, resulting
in fewer doses and more rapid analysis times. In order to avoid overshooting, target pressures are
decreased as the sample approaches equilibrium.

NOTE! It is recommended to keep the MaxiDose box checked on.
3.2.6
Leak Test
Specify the duration of the leak/pressure-rise test (from 0 to 30 minutes). Normal value is 1.
3.2.7
P0 Options
The saturated vapor pressure of the adsorbate (P0) is required for data acquisition and reduction.
The P0 menu presents the following options for P0 values. Only one option can be selected at any
time:
P0 Station:
To use this option, which measures P0 in a dedicated cell, place an empty,
clean, dry P0 cell in its station. During sample initialization, the system
liquefies adsorbate in the P0 cell and reads the vapor pressure as needed
during the analysis. You should enter an approximate P0 value in the box
to the right of the menu; it is used by the instrument in the initialization
procedure. P0 Station is the recommended mode of operation when
57 of 158
Autosorb-6iSA/ASWin Operating Manual
F. INSTRUMENT OPERATION
operating near the boiling point of the adsorptive, e.g. when using nitrogen
at liquid nitrogen temperature.
Interval: The measured P0 Station value is updated at a user selected
interval (up to 999 minutes). Since the manifold and its transducer are
required for the update, frequent updates can delay the acquisition of data
points. An interval of no less than 120 minutes is recommended.
Open to ambient:
In this mode the system measures ambient pressure and uses this value to
calculate P0 by adding 5 mm Hg for nitrogen or by using the ClausiusClapeyron Equation for krypton type gases (see 7). When this option is
chosen a cell or plug must be placed in the P0 station. The system will first
perform a transducer scaling, then indicate when the cell or plug is to be
removed. This P0 type is not updated during the analysis.
User Entered:
User Entered P0 is recommended when measuring P0 is not practical (e.g.
when operating far from the boiling point of the adsorptive). Enter the
value of P0 in the box to the right of the menu. It can also be used to save
some time when measuring just B.E.T. surface areas. For an adsorptive at
its own boiling point (e.g. N2 @ 77.4K) ambient pressure plus 10 Torr is a
good approximation for P0. For example, if the ambient pressure is 757
Torr, then enter a value of 767 Torr. This P0 type is not updated during the
analysis.
Calculated:
The Calculated value method of determining P0 is similar to Open to
Ambient except that the User-entered value is used instead of measuring
ambient pressure. You must enter a value for ambient pressure (in Torr) in
the box to the right of the menu. This P0 type is not updated during the
analysis.
3.3 Start Analysis Error Messages
Any incomplete or conflicting parameters entered during the setting up of analysis criteria for
active stations (i.e. those on which you intend to start an analysis) will result in one or more error
messages displayed immediately below the Start Analysis window (see Figure F.7). Double-click
on an error message to jump to the appropriate field. Once valid information has been entered the
error message will be cleared automatically. Note: only essential parameters are tracked. Nonessential parameters, such as MaxiDose (on or off), sample ID and description, are not tracked. It
is the responsibility of the user to ensure all such information is correct.
58 of 158
Autosorb-6iSA/ASWin Operating Manual
F. INSTRUMENT OPERATION
Figure F-7, Error messages.
3.4 Selecting Points
Click the Points tab at the top of the station page to select (P/P0) points, calculation tags, and
equilibration criteria for the specific station analysis.
The Points page contains the list of the currently entered P/P0 values (if any) that define the
analysis, their equilibrium criteria, and the tags assigned to them. The points (to be measured) are
sorted by their tags A (Adsorption), D (Desorption) and the relative pressures in order of
increasing adsorption relative pressures followed by desorption points’ decreasing relative
pressures (newly added points are automatically inserted at their proper positions).

NOTE! Before selecting data points, set the equilibrium criteria: Tolerance and
Equilibration (for details on what they mean, see Appendix 5). Each group
of points (P/P0 values) subsequently added will use the values displayed in
the Tol: and Equ: windows. A tolerance of 2 and an equilibration (time) of 3
(minutes) are usually appropriate.
A/D Tags are used by the software to denote whether a point is an adsorption point, desorption
point, or both adsorption and desorption (such as the top of the isotherm, P/P0 ~ 1). Thus, before
any Point can be added must have at least an “A” tag (Adsorption) or a “D” tag (Desorption). If
neither of these tags is present, the Add point button will be grayed out.
59 of 158
Autosorb-6iSA/ASWin Operating Manual
F. INSTRUMENT OPERATION
Enter the P/P0 of an
individual point and click
the Add point button.
All data points
must have at
least an A or a
D tag assigned.
Prior to selecting data
point(s), enter
equilibration criteria.
Click here to load from
pre-set auto-selection
of data points.
Enter the limits
of P/P0 range in
these fields.
Enter the total
number of points in
the Cnt field and
click Add button.
P/Po data points
selected using this dropdown list do not replace
each other but are
additive (duplicated
points are automatically
removed)
Figure F-8, Selecting points for acquisition.

NOTE! MicroPore points should not normally be selected on the Autosorb-6iSA (It
does not have the necessary turbo pump and low pressure transducer). This
software feature is included for users of earlier Autosorb 6B Kr units with
which this software version will also function.
Data point tags are also used to specify specific points used in selected data reduction
calculations available in ASWin. These tags may be also added/removed after an analysis; see
Section G.6 Setting Data Reduction Tags.
60 of 158
Autosorb-6iSA/ASWin Operating Manual
3.4.1
F. INSTRUMENT OPERATION
Adding a Single Point
To add points one at a time or to add a single point to an existing list, enter the relative pressure
in the Add point field, select the A/D option (Ads, Des, Ads+Des), select any other tags desired,
set the Tol and Equ parameters, and click the Add button. Only one point (the highest pressure
point) can have the Ads+Des option selected; all other points need to be defined as adsorption
(Ads) or desorption (Des).
As points are selected, they will be added to the Point List table which displays up to nine points
at a time. All of the points can be viewed by scrolling through the list of points using the up and
down arrows on the scroll bar on the right side of the table.
3.4.2
Adding Range of Points
To add multiple, evenly spaced points, enter the first and the last relative pressure value in the
appropriate fields in the Spread points section, the number of points (including the first and the
last point) in the Cnt (count) field, select the tags, and click on the Add button. The minimum
spacing between points is 0.0025 P/P0.
3.4.3
Standard Point Sets
Make sure to select desired equilibration parameters before selecting Std Point Sets. (See
Section F.3.4.5). Clicking on the Std Point Sets button displays a menu, from which common
combinations of points may be chosen.
3.4.3.1
BET points
You can select predefined point(s) for measuring data used in a single point BET and/or
Multipoint BET (3–11 points) surface area analysis. Make sure to select desired equilibration
parameters before using this option. Appropriate BET points will be automatically added to the
point list and tagged (S and/or M, in addition to A). See Figure F-9.
When selected, the Single point BET option will load a data point at a relative pressure of 0.3
and flag it for a single point surface area measurement. The multipoint options will select the
requested number of points, spaced evenly between 0.05 and 0.3 P/P0. These points will have the
M tag set.
Figure F-9, Predefined points for BET analysis.
3.4.3.2
Adsorption/Desorption Points
You can choose to add predefined adsorption and desorption data points (10-40 points, for each
branch). Make sure to select desired equilibration parameters before using this option. Points will
be added up to P/P0 of 0.995, starting at 0.025 or 0.05 or 0.1 in case of 40, 20, or 10 adsorption
points, respectively.
61 of 158
Autosorb-6iSA/ASWin Operating Manual
F. INSTRUMENT OPERATION
Figure F-10, Predefined adsorption/desorption points.
3.4.3.3

Micropore Point Selection (Autosorb 6 Kr users only)
NOTE! MicroPore points should not normally be selected on the Autosorb-6iSA (It
does not have the necessary turbo pump and low pressure transducer). This
software feature is included for users of earlier Autosorb 6B Kr units with
which this software version will also function.
Click on MicroPore Points button to open the Add Micropore Points dialog which allows you
to automatically add a set of low P/P0 points for micropore analysis:
Figure F-11, Adding micropore points.
Select the decade from which to start adding points and select the spacing option. Points will be
added according to the requested spacing starting in the specified decade. Standard Spacing
adds 10 points per decade, Augmented Standard adds additional points in between, and
Equally Spaced will add points such that they are equally spaced in a semi-log display. Points
added with this dialog may be deleted or modified. See Section F.3.4.4.

NOTE! For micropore measurements it is recommended to use Tolerance = 0 and
Equilibration time = 4 minutes or more.
62 of 158
Autosorb-6iSA/ASWin Operating Manual
3.4.4
F. INSTRUMENT OPERATION
Modifying the List of Points
To delete point(s) from the list, highlight selected points (or click All button) and then click the
Del button below the list.
Selecting point(s): click on a single point, or use the Windows multiple item selection method
(from your keyboard, press and hold SHIFT; use arrow buttons to go up or down). Selected
points will be highlighted. The All and None buttons will select or deselect all data points,
respectively. The Del button will completely delete all highlighted data point(s). None and Del
buttons are grayed-out unless at least one data point is selected.
To set a flag for given data point(s), highlight the point(s), check the on or off box flag, to add or
remove tag respectively, and click on Apply to selected button. The tag is on for a given data
point when the corresponding letter is displayed in the same row (on the list of points). Multiple
tags can be assigned to each point:
A
D
M
S
T
V
L
P
R
appears if the point is specified as an adsorption point.
appears if the point is specified as a desorption point.
appears if the point is specified for use in the multipoint BET calculation.
appears if the point is specified for use in the single point BET calculation.
appears if the point is specified for use in the statistical film thickness calculation.
appears if the point is specified for use in the total pore volume calculation.
appears if the point is specified for use in the Langmuir calculations.
appears if the point is specified for use in the pore size distribution calculations.
appears if the point is specified for inclusion in the Dubinin-Radushkevich and Fractal
analysis.

NOTE! Each sample analysis is limited to a maximum of 180 points (combined
total of all adsorption and desorption points). Check that this value has not
been exceeded before clicking START.
3.4.5
Equilibration Criteria
The following criteria are used during the measurement to establish if a given experimental point
may be accepted as a valid point on adsorption or desorption isotherm:
Tolerance:
Select a P/P0 tolerance from 0 to 9. A tolerance value of 0 ensures the
tightest match between the relative pressures selected and the relative
pressures achieved (typically 0.001 atm.) while a tolerance of 9 results in a
faster analysis with a looser relative pressure tolerance (typically 0.01
atm.) A tolerance of 2 is recommended for most sample types. For details,
see J. 2.
Equilibration:
Select an equilibration time between 1 minute and 99 minutes. A value of
3 is recommended for most sample types.
63 of 158
Autosorb-6iSA/ASWin Operating Manual
F. INSTRUMENT OPERATION
3.5 Data Reduction and Analysis Reporting Page
From the Start Analysis window, click on the Data Reduction tab to set-up options for: postanalysis data reduction, auto-reporting and archiving.
3.5.1
Auto-report
You can choose to have a report created automatically upon completion of the analysis. Select
the name of the report from the dropdown list (Fig F.12) to have it open up on screen when the
analysis is completed. If <none> is selected, no report will be opened upon completion of the
analysis.
Selecting the Export Result drop down menu
will allow you to select either “No export”
which will indicate that you do not want to
export your file, or the file type that you would
like to export your file as.
Check print box if you would
like to have the report printed
automatically.
Selecting the Open report
drop down menu allows you to
select what file type you would
like the report to open as.
Selecting the Save as text drop
down menu allows you to
select what file type you would
like the report to save as.
Click here, to open
Data
Reduction
Parameters window.
Selecting the Archive Result drop down
menu will allow you to choose if you would
like to archive your data (“No Archival”) or
where you would like to archive your data
(“result archive folder” or “custom folder”).
Figure F-12, Data Reduction Ta– - Selecting autoreport template.
The report names are determined by the user through the Report Manager feature (see Section
H.5). Check the Print box to have the report printed to the Default System printer.
64 of 158
Autosorb-6iSA/ASWin Operating Manual
3.5.2
Archive Result
3.5.3
Set Data Reduction
F. INSTRUMENT OPERATION
To save a copy of the data file, automatically upon completion of the analysis, locally or across
your network, use the Archive Result option on the Data Reduction Tab’s Result postprocessing section (see section D. 4.4 for more information regarding default folder locations).
If you choose Custom Folder you will be asked to enter its location. To export the file to .drf use
the Export Result option within the Result post-processing section and select .drf from the drop
down menu.
Additionally, the Data Reduction parameters assigned to the file can be set up by clicking the Set
Data Reduction Parameters button. This will bring up the Data Reduction Parameters dialog,
where the desired values can be selected:
Switch between available TABS, to set appropriate
Data Reduction Parameters (for example:
General, or DFT/Monte-Carlo).
Figure F-13, Setting the data reduction parameters.

NOTE! For details on Data Reduction Parameters set-up, see Section D.4.3.
65 of 158
Autosorb-6iSA/ASWin Operating Manual
F. INSTRUMENT OPERATION
3.6 Viewing Summary of Analysis Parameters
Click on the Summary tab near the bottom of the Start Analysis window to display a summary of
the six stations for quick verification prior to starting the acquisition.
Figure F-14, Displaying a summary of analysis parameters.
66 of 158
Autosorb-6iSA/ASWin Operating Manual
4
F. INSTRUMENT OPERATION
Saving/Retrieving Analysis Parameters

NOTE! Users at the Operator level can only Load Preset parameter sets. They
cannot Save Preset, Load/Save Station, or Load/Save Points.
To save or retrieve (previously saved) analysis parameter settings click the Load/Save button at
the bottom of the Start Analysis window. This activates the following drop-down menu:
Figure F-15, Saving and restoring parameters.
Click one of the menu items to perform one of the following operations:
Load or Save Preset will retrieve or store settings for all six analysis stations from or to a
named user file, respectively.
Load or Save Station will retrieve or store the settings for the current station from or to a named
file, respectively. If the Summary tab is selected an error will be
displayed.
Load or Save Points will retrieve or store the point selection for the current station from or to a
named file, respectively. If the Summary tab is selected an error will be
displayed.
A standard file selection dialog is displayed. Enter or select the desired filename and click Open
or Save to complete the operation.
5
Start and Monitor Analysis
After all of the required fields on the Start Analysis window have been entered correctly (and
any error box has disappeared, see F 3.3), the Start button will be enabled.
Make sure you have selected () only those stations that you intend to analyze (“Active
Stations”). Also check that you have done the following:
•
Installed sample cells (with properly outgassed samples and filler rods) on the active
stations,
•
placed a dewar filled with the correct coolant on each of the active stations,
•
relevant coolant level sensors are securely attached,
•
Po cells attached if required (Po station option),
67 of 158
Autosorb-6iSA/ASWin Operating Manual
F. INSTRUMENT OPERATION
•
adsorbate and helium gases attached and set to 8-10 psig (and that any isolation valves
are open), and
•
installed the blue Dewar shields.

NOTE! Each sample analysis is limited to a maximum of 180 points (combined
total of all adsorption and desorption points). Check that this value has
not been exceeded before clicking START by using the Summary tab
(Fig F.14).
Click the Start button to begin the analyses. If you click on OK (edited settings will be
maintained when this window is re-opened) or on Cancel (edited changes will be lost), the Start
Analysis window will close without starting the run.
After an analysis has been started, it is useful to be able to monitor the run progress —
particularly, since full isotherms may take an extended period of time to complete. ASWin offers
the following features to accommodate this need:
• Instrument Message Log window
• Instrument Status window
• Automatic uploading of acquired data points
5.1
Instrument Message Log/Monitor Instrument
As soon as the measurement (or cell calibration) is initiated, the Autosorb Multistation
Communicator window will appear. The Messages tab of this window shows the messages
being saved to the log file. This is useful to track the progress of an analysis. The
Status/Upload/Abort tab shows the current status on all of the stations.
The software keeps a running log of all messages. The location of the log files can be selected by
using the Set Data Folders function from the Configure menu, for details, see Section D.4.4.
To view the Messages window regardless of the instrument status, click Show Instrument
Message on the Operation menu (or click Ctrl + B).
68 of 158
Autosorb-6iSA/ASWin Operating Manual
F. INSTRUMENT OPERATION
Uncheck this box if
you would like to
scroll manually.
Click here to start a
new log file
Click here if you would
like to add a time stamp.
Figure F-16, Instrument Message Log
This dialog box allows you to monitor in real time the details of instrument operation. Its
primary function is diagnostics; however, it can be used to record each operation performed by
the Autosorb -6 iSA during an analysis.
In addition, the ASWin 2.0 software will always save log information into a file whose name is
automatically generated (based upon the start time). The file will only be created when the first
log message is saved. The user can manually invoke recording of a new (separate) log file, by
clicking on the Start New button in the Log window.
The LogFile information will be valuable if it is necessary to call with a question about the
operation of the instrument.
Click the TimeStamp button, to mark a particular instrument status at a particular time. Enter
your comment and click OK:
Figure F-17, Instrument Time Stamp
69 of 158
Autosorb-6iSA/ASWin Operating Manual
F. INSTRUMENT OPERATION
5.2 Instrument Status Dashboard
To obtain brief information about current status of the analyses, click Instrument Status on the
Operation menu, type <Ctrl><B>, or press F8 on the PC’s keyboard. The status of all the
analysis stations, the progress of the analysis, and the current P0 (in Torr) are displayed.
Total points requested
If the Autosorb-6iSA is
busy you might see this
message.*
Points acquired so far
Click Refresh to make
sure you are looking at
the most recent status
Figure F-18, Displaying the status of all six stations.
*The instrument may fail to respond because it is busy (certain steps within an analysis are time
critical, and communication monitoring is disabled during those steps) or a communication error.
Close the window and try again later.
5.3 Uploading Data Points
Data points are automatically displayed on the PC as they are acquired during the analysis. If the
program has been closed at the time the last data points were acquired, you may upload the data
from the instrument by clicking Upload data on the Operation menu (or press F9 from the
computer keyboard. This will bring up the Status… display (Fig F.18). Select one or more
stations and click Upload Selected. This will initiate a query to the instrument and the computer
will read the data currently stored in the Autosorb-6iSA into the file(s) designated to save that
data. A graph of the isotherm will be displayed (Fig. F.19). Any desired data reduction can be
performed so long the data necessary for the calculation has already been acquired.
70 of 158
Autosorb-6iSA/ASWin Operating Manual
F. INSTRUMENT OPERATION
Figure F-19, Uploaded isotherm graphs after selecting “Upload Selected”.

NOTE! The data file(s) created when the analysis started must remain in the
directory where they were created. If they are moved or deleted, or if the default
path for storing data files changes, the data upload will fail. If you ultimately
need the data in a different location you must wait until the analysis is
completed; you can choose to have a copy created automatically in the location
of your choosing using the “Archive” function: see F. 3.4.2.
5.4 Abort Analysis
To abort the analysis, click Abort Analysis on the Operation menu. This brings up the
Status/Upload/Abort window. Select the station(s) to about and click on Abort Selected. To
abort all stations, click on Abort All Active. This selection must be confirmed, thus preventing
accidental aborts. Select Yes to confirm (analysis will be aborted) or No to cancel.
A message box will inform you about instrument aborting the run, and when the run is actually
aborted, the message is also displayed.
71 of 158
Autosorb-6iSA/ASWin Operating Manual
F. INSTRUMENT OPERATION
5.5 Manual Mode
Selecting Manual Mode from the Operations menu gives complete manual control of the
system’s valves and Dewar elevators while displaying the system temperature and pressures.
!
CAUTION! Improper valve manipulation can damage instrument components,
and could cause hazardous situations. Entering manual mode while an
analysis is in progress is not recommended, since this mode stops automatic
processing and can allow a system over pressurization. It should never be
used for routine operation of the instrument or by people not thoroughly
familiar with the instrument.
 NOTE! Access to Manual Mode during analysis can corrupt data.
Select
Evacuation:
Fine or Coarse.
Click each box to
open/close the
valve (uncheck/
check the box,
respectively)
Click here
to close all
the valves.
Click here to move the Dewar up
(green arrow) or down (red arrow).
See Caution message below.
Figure F-20, Manual mode display on the Autosorb-6iSA.
72 of 158
Autosorb-6iSA/ASWin Operating Manual
!
F. INSTRUMENT OPERATION
CAUTION! Moving a dewar - containing liquid coolant - down could cause
over-pressurization of the system due to rapid desorption of adsorbate from
the sample and/or evaporation of liquid or solid adsorbate within the P0 cell
This over-pressurization has the potential to eject cell(s) from the station(s).
Manual Mode controls:
Legend:
Open valve,
Closed valve
Pressure transducer
•
Valves are represented by check boxes as above. Click on the symbol to change its
state. Due to a slight delay in the reaction of the instrument to the program request,
the color change of the box may be delayed compared to your clicking on the box.
•
Pressure transducers’ current measured pressure values are displayed and updated
as fast as the communication between the instrument and the PC allows. Note that
station transducer values are displayed below each station Dewar.
•
Dewar positions are, for simplicity, shown at the top, at the bottom, or somewhere
in between. To set the direction of the Dewar travel click on either triangle arrow
button below the station. These buttons remain depressed showing the last
requested direction.
•
Vac SetPoint displays the reported state of the vacuum system, above or below
•
Click Close all valves to close of all valves at once.
•
Click Close to exit manual mode and return to normal operation. All valves and the
Dewar flask will be restored to their original status.
setpoint.
On legacy Autosorb 6B models equipped with a turbo pump (krypton/micropore), it is possible
to overload the pump and stall it, in which case a small light towards the bottom of the long front
panel will be illuminated. It can be reset by pressing the black reset button adjacent to the light.
The turbo pump button will work only if the krypton or micropore option is installed.
73 of 158
Autosorb-6iSA/ASWin Operating Manual
G. DATA ANALYSIS USING ASWin
G. DATA ANALYSIS USING ASWin
In addition to providing PC control over the measurements, ASWin is also a comprehensive
program for enhanced data analysis and calculations that provides features such as graphical
plots, alternative theoretical models, as well as reporting, external data archiving and editing
capabilities.
1
Accessing Data Files
For results calculation, enhanced data analysis and reporting, first open or import the desired
file. See Table G.1 (below) for factory-default directory locations for the different file types
supported and Section D.4.4 for details how to change them. A file elsewhere on your PC or
network can be found using the familiar Windows navigation tool:
Figure G-1, Navigating to a File Folder
Alternatively, to access a recently used file(s) click Reopen on the File menu or click the Recent
List Icon
on the Main menu bar.
2
File Types
2.1 “Open”
Three types of file can be opened directly using the File,Open function or clicking on the open
folder icon
. These file types are shown in Figure G-2 and described in Table G.1.
74 of 158
Autosorb-6iSA/ASWin Operating Manual
G. DATA ANALYSIS USING ASWin
Figure G-2, Selecting the type of file to open.
2.2 “Import”
A further four file types can be imported and manipulated in the same way as a standard QPS
file. These file types are shown in Figure G-3 and described in Table G.1.
Figure G-3, Selecting the type of file to import.
Below is a table describing the file types that can be used in the ASWin software:
Table G.1, File Types
Type of File
Assigned
Extension
Access
Comment
Default Directory
Quantachrome
Physisorption Data
Documents
.qps
Open
Physisorption files generated by this and other newer
Quantachrome software
(including Quadrasorb and NOVAe)
Physisorb
Autosorb RAW Data
Documents
.raw
Import
Autosorb (Autosorb-1, Autosorb-6B and Autosorb
3B) physisorption files (volume, P/P0)
PhysData
Instrument Data (NOVA,
HS) Documents
.dat
Import
Nova and Hydrosorb files obtained from
instrument’s User (floppy) Disk
Instrument Data
Physisorption DRF Data
Documents
.drf
Import
Older Autosorb physisorption Data Raw Files
(volume, pressure, Po, time) and optional exported
file format in this software
PhysData
NovaWin 1.x Data
Documents
.qnv
Import
Old NovaWin files
(all versions 1.x)
Instrument Data
Auxiliary Data
Auxiliary Data
Physisorption Overlay
Documents
.ovp
Open
Overlays of plots. This file does not contain the actual
data but is a pointer to the files included. Therefore it is not
portable to a different PC (unless the individual source
files are also ported over into the exact same path!)
Heats of Adsorption
Documents
.hoa
Open
Heats of Adsorption files
75 of 158
Autosorb-6iSA/ASWin Operating Manual
G. DATA ANALYSIS USING ASWin
Imported files can only be saved (after any form of allowed editing) in
 NOTE!
*QPS format.
3
Using the Database for Searching .qps Data Files
3.1 Locating Analysis Results
In order to quickly locate specific analysis results, go to Edit menu and click on Search
Database. You can specify a number of criteria to select from analysis results stored in the
database. This feature searches only within .qps file types (see Table G.1, File Types, above).
Figure G-3, Locating files using the database manager.
Enter values in the Sample ID, Sample Desc, Operator and Comment fields to list only those
results whose corresponding fields match the pattern entered. Each field can contain an asterisk
(*) character at the beginning and/or at the end of the field value. The asterisk will match any
number of any characters in the data fi’e's field value.
Example: The field value of alpha* will match any of the alpha, alphabeta, alpha999 values,
but will not match alph, XXalpha, XXalphabeta. The field value of *alpha* will match any of the
XXalpha, alphabeta, XXalpha999 values, but will not match alph, lpha. If no asterisk is included,
the field must match exactly. In the example shown in Fig. G.2 (above) the search terms SARM
76 of 158
Autosorb-6iSA/ASWin Operating Manual
G. DATA ANALYSIS USING ASWin
or 2005, without asterisks, would not find the files shown – but SARM 2005 (an exact match)
would. Fields left empty are excluded from the selection criteria.
In addition, a date range can be specified. Check the box Use date range and specify a starting
and ending date utilizing the two calendar controls. Note that the dates are inclusive, for
example, specifying 1/1/2012 as a start date will include analyses performed on 1/1/2012 and
later; the search will omit files that are outside of the date range.
Once all criteria are specified, click the Search button to start the search. If the result contains
more than 100 files, a prompt will offer the choice to stop and revise the criteria or to continue.
Once the search is completed, matching records are listed in the lower half of the window,
displaying all relevant information of the entry (not just those used for the search). Use the
scrollbar to see all matching results, and double-click on an entry to open the corresponding data
file. If a data file was created using older version software, a “backwards-incompatibility” alert is
displayed.
Click on the Close button to exit the Database/Data Manager.
3.2 Rebuilding Physisorption Database
To allow inclusion of data files already existing on the us’r's computer, the software provides the
Database rebuild function. To access this feature, select the Build tab from the Database
manager window:
Figure G-4, Rebuilding the database.
Here, a list of locations can be entered. The software will remember these selections, and will
reload them whenever the function is invoked.
Use the Add button to specify a folder to be included, the Remove button to remove the selected
line from the list.
77 of 158
Autosorb-6iSA/ASWin Operating Manual

G. DATA ANALYSIS USING ASWin
NOTE! Each folder entry will also include all subfolders under it.
Once the folder list is complete, click on the Rebuild button to start the process. If the Empty
before building box is checked, the current contents of the database will be discarded.
The build process can take several minutes, depending on the number of analysis files contained
in the selected folders. The status bar at the bottom of the window will display the file currently
being processed.

NOTE! Only .qps data files are included in the rebuild function.
Once the process is complete, the Close button can be used to leave the feature, or selecting the
Search tab will return the user to the Database Search function.
4
Floating Menu
The Floating Menu is the main navigating tool used to obtain tables, plots and reports including
raw data and results calculated using various data reduction methods. To activate the Floating
Menu, right-click on an open graph or a table associated with a given measurement data file. The
Floating Menu will give you an access to the results related to this file. If you right-click on a
document associated to another data file, you will gain access to the results from that file. The
floating menus vary slightly depending on whether you right-click on a plot or a table.
4.1
Floating Menus on Plots
78 of 158
Autosorb-6iSA/ASWin Operating Manual
G. DATA ANALYSIS USING ASWin
4.2 Floating Menus on Tables
5
Editing Analysis Data Information
To edit the header information of the data file, open the file, right-click on the graph and select
Analysis Data. This opens the Analysis Data window:
Figure G-5, Editing analysis data.
The Analysis Data window contains the information that is displayed in the header of each page
of the report. If a parameter that is used for calculating reduced data is changed, such as the
sample weight, the data will be recalculated when OK is selected. Clicking Cancel will
disregard any changes to this window.
79 of 158
Autosorb-6iSA/ASWin Operating Manual

G. DATA ANALYSIS USING ASWin
NOTE! Any changes to the Analysis Data window will be lost when the file is
closed unless the file is saved using Save or Save As from the File menu.
Alternatively, you may click the Save Icon
on the Main Tool Bar.
If you attempt to close the file without saving, you will be prompted to make a decision:
Figure G-6, Prompt to save data.
When running the CFR version of ASWin, only the Superuser security level will have the
option to change the information in this window. Any changes to the Analysis Data window will
prompt the Superuser to state the reason for the change for documentation in the audit trail.
Figure G-7, Documenting changes for documentation in the audit trail.
6
Setting Data Reduction Tags
To select or modify data tags for a given data file, right-click on an open plot or a table
associated with this file. This activates the Floating Menu (see Section G.4). Click Edit data
tags on this menu to open the following window:
80 of 158
Autosorb-6iSA/ASWin Operating Manual
G. DATA ANALYSIS USING ASWin
Figure G-8, Editing data reduction tags for physisorption data.
The tags A (or D or AD, not shown) in the first column next to the volume values indicate that a
given point belongs to the adsorption (A), desorption (D) or both (AD) branches of the isotherm.
These tags are applied automatically and cannot be changed.
The tags shown in the Tags column indicate which data reduction method will be applied to the
points marked by a given tag. The following is the list of tags and their corresponding data
reduction methods:
•
M — Multi-point BET (Surface Area)
•
S — Single-point BET (Surface Area)
•
T — Statistical Thickness (including STSA method)
•
V — (Total) Pore Volume
•
L — Langmuir (Surface Area)
•
P — Pore Size Distribution (BJH and Dollimore Heal only)
•
R — Dubinin - Radushkevich (DR Micropore method) and Fractal
To make changes to the list of points follow the steps:
1
Select points by using the Windows standard selection method (click to select one
point, Ctrl-click to toggle an item's selection state, Shift click to select range from
last clicked item), or use the Select All or Select None buttons.
2
Then check a box in the same row as the tag you want to apply. The box should
be checked in the ON column to add tags or OFF column to remove tags.
81 of 158
Autosorb-6iSA/ASWin Operating Manual
G. DATA ANALYSIS USING ASWin
3
To apply changes, click Apply to Selected.
4
Use the Clear button to deselect all tag checkboxes. Note: this does not clear the
tags from the data points
5
Click Delete to remove the selected points permanently. (CFR version: This
button is available only at the Superuser level.)
6
Click OK to return to the main program. All related calculations will be reevaluated, and the new results will appear in the open tables or graphs
7
Click Cancel to discard the changes and return you to the main program.

7
NOTE! for ASWin-CFR: All changes are tracked in the audit trail.
Setting Data Reduction Parameters
To set/modify certain parameters for tagged calculations and other methods click Data
Reduction Parameters on the Floating Menuto open the dialog in The parameters are grouped
on the same pages according to their applications. Use the tabs on the top of the window to
navigate through different pages.
82 of 158
Autosorb-6iSA/ASWin Operating Manual
G. DATA ANALYSIS USING ASWin
Figure G-9, Editing data reduction parameters.
Click Save (
) or Load (
) to store/retrieve full set of parameters. The .drp files are
stored in the program's ASWinCfg folder as “DRP sets.”
Click Cancel to close the window without saving changes.
Before referring to specific calculation methods click the Adsorbate and Adsorbent tabs to
check if the correct adsorbate and adsorbent are selected for the analysis. Table G.2 provides a
general guide for the Tag selection based on the analysis type and gas sorption calculation
methods. A detailed discussion of the methods listed below can be found in Section I.
Table G.2, Typical Pressure Ranges for Gas Sorption Calculation Methods
P/P0 Range
Calculation Model
-7
10 – 1
NLDFT, QSDFT, GCMC
0.0001 – 0.1
DR, DA
83 of 158
Autosorb-6iSA/ASWin Operating Manual
G. DATA ANALYSIS USING ASWin
< 0.15
HK, SF
0.05 – 0.3
(Classical BET range)
BET
> 0.15
t-plot, alpha-s, FHH, DFT
> 0.35
BJH, DH, Fractal –FHH, NK
7.1 Parameters for NLDFT and GCMC Methods
No tags are required for The Non-Linear Density Functional Theory (NLDFT) and Grand
Canonical Monte Carlo (GCMC) methods.
To access the parameters for these methods, click the DFT/Monte Carlo tab on the Data
Reduction Parameters window and then click the DFT or Monte Carlo tab.
Enable calculation
by checking-ON
this box
Figure G-10, Setting DFT or Monte Carlo parameters.
In order to use the DFT / Monte Carlo Method to calculate pore size distribution curves and
histograms, you must first enable the method by checking the calculation enabled box. Next,
select the appropriate DFT/Monte Carlo Kernel from the Calculation model drop-down list.
Adjust the minimum and maximum relative pressure range in the Range (relative pressure)
box. It is recommended to use the entire relative pressure range of the DFT model (10-7 to 1)
regardless of the range over which the measurement was performed.
84 of 158
Autosorb-6iSA/ASWin Operating Manual

G. DATA ANALYSIS USING ASWin
NOTE! Please refer to Table I.2, List of available kernels for DFT and GCMC
methods. in Section I. for a comprehensive description of Quantachrome’s listing of
DFT and GCMC methods.
Click the Interpolation Settings button on the DFT or Monte Carlo page to open the
Interpolation Parameters window where you can set the appropriate diameter ranges and
intervals for the interpolation:
Figure G-11, Setting interpolations ranges for DFT or Monte Carlo methods.
Check the Use Interpolation box for interpolation to be applied in the calculation.

NOTE! Interpolation must be off (use Interpolation unchecked) for pore
size/volume and histogram calculation.
Click the Save button (
) when finished. Assign a name to the settings to save the file name
with the extension “.qip.” Recall a file at a later date by pressing the Load button (

).
NOTE! For most applications, it is not recommended to use the interpolation
function (uncheck use Interpolation box).
85 of 158
Autosorb-6iSA/ASWin Operating Manual
G. DATA ANALYSIS USING ASWin
7.2 Review of the Data Analysis Methods
7.2.1
HK: Horvath Kawazoe Method
SF: Saito Foley Method
Tags: None
Click the HK, SF tab on the Data Reduction Parameters window to access parameters for
these methods:
Figure G-12, Setting the parameters for HK and SF methods.
Click the On button to engage the calculation for the method(s) that you wish to use. The
Tabulated data interval is the number of data points that will be displayed on the data tables.
For example, if you wish to tabulate every other data point, a value of 2 should be entered for the
Tabulated data interval.
7.2.2
DA: Dubinin Astakhov Method
Tags: None
7.2.3
BJH: Barrett, Joyner & Halenda Method
DH: Dollimore Heal Method
Tags: P
Click the BJH/DH, DA tab on the Data Reduction Parameters window to access parameters
for these methods:
86 of 158
Autosorb-6iSA/ASWin Operating Manual
G. DATA ANALYSIS USING ASWin
Figure G-13, Editing parameters for BJH, DH, and DA methods.
The BJH and DH methods can be used to calculate pore size distribution curves and tables for
the adsorption and/or desorption branches of the isotherm. Tag the appropriate adsorption and/or
desorption data points with the P tag. This calculation uses the statistical thickness of the
adsorbed layer of the adsorbate on the surface of the sample so you must choose a t-method
calculation method (de Boer, Carbon Black, Halsey, or Generalized Halsey) to use in the BJH
and/or DH calculations.
The Moving point average determines number of points averaged in a sliding window average.
Set this value to 1 in order to include all of the P-tagged data points in the calculation without
averaging.
Check Ignore P tags below 0.35 P/P0 to ignore these points in the calculation (recommended).
To set interpolation ranges for the BJH / DH method calculations, click the BJH Interpolation
Settings button to access the Interpolation Parameters window (below).
87 of 158
Autosorb-6iSA/ASWin Operating Manual
G. DATA ANALYSIS USING ASWin
Figure G-14, Setting interpolation parameters for BJH/DH methods.
Fill in the desired ranges in the fields provided. Check the box for adsorption and/or desorption
branch of the isotherm. Finally, save your selected interpolation ranges by clicking the Save
button. Click OK or Cancel to close the Interpolation Parameters window.
Click the On button in the DA Method box to enable the calculation. Adjust the other values
related to the DA Method.
7.2.4
DR: Dubinin Radushkevich Method
Tags: R
Employing the DR method only requires that you set R Tags for the desired P/P0 points in the
measurement. The value of the DR exponent (n) can be adjusted on Adsorbent page of the Data
Reduction Parameters window.
7.2.5
BET: Brunauer, Emmett, & Teller Method
Tags: M (Multi-point), S (Single-point)
If you want to calculate the Multi-point BET surface area for the sample, set the appropriate data
points with the M tag. Use the S tag (usually around P/P0 = 0.3) if you would like to calculate the
value for the Single-point BET.
The BET surface area calculation requires a linear plot of 1/[W(P0/P)–1] vs. P/P0 which for most
solids, using nitrogen as the adsorbate, is restricted to a limited region of the adsorption isotherm.
For nonporous materials this is usually in the P/P0 range of 0.05 to 0.30, however, this linear
region is shifted to lower relative pressures for microporous materials. A typical BET plot is
shown in Figure G-15. The standard multipoint BET procedure requires a minimum of three
points (preferably five) in the appropriate relative pressure range. If the Y-intercept is negative
and/or the points clearly do not fall on a straight line, the point range should be adjusted as
described below.
88 of 158
Autosorb-6iSA/ASWin Operating Manual
G. DATA ANALYSIS USING ASWin
Figure G-15 , Typical BET Plot
The BET equation is certainly applicable to nonporous solids and materials consisting of pores of
wide pore diameter. But, in a strict sense, it is not applicable to microporous adsorbents.
Notwithstanding the problems arising from the chemical and geometrical heterogeneity of the
surface, the type of porosity (i.e. macro-, meso-, or micropores) therefore plays an important role
in the applicability of the BET equation.
The problem is that it is difficult to separate the processes of mono-multilayer adsorption from
micropore filling — usually completed at relative pressures (P/P0) below 0.1. Another problem is
associated with the size and shape of adsorptive molecule, i.e. the effective yardstick used to
assess the surface area.
In case of very narrow cylindrical micropores (ultra-micropores < 0.7nm), the area calculated by
the BET analysis to be covered by the adsorptive is significantly smaller than the total geometric
area. Take ZSM-5 (an aluminosilicate zeolite used as an isomerization catalyst in the
petrochemical industry) for example; because of the extreme curvature of the ca. 0.5 nm pore
channels and the relatively large size of the probe molecule, the BET analysis underestimates the
true surface area (it assumes the molecules to be adsorbed on a flat surface, on one side!).
Conversely, in broader super-micropores (> 0.7 nm), a number of molecules, those filling in the
center of the pores, do not touch the surface, and this leads to an overestimation of the surface
area. Therefore, the surface area obtained by applying the BET method on adsorption isotherms
from microporous solids does not reflect the true internal surface area, but should be considered
as an "equivalent BET area.”
The application of the BET method is also problematic for estimating the surface area of
mesoporous molecular sieves of pore widths less than ca. 4 nm, because pore condensation is
observed at pressures very close to the pressure range where monolayer-multilayer formation
occurs on the pore walls. This may again lead to a significant overestimation of the monolayer
capacity (hence surface area) when using the BET method. In any case, the range of linearity for
the BET plot over which the surface area is calculated must be reported with the surface area.
The question remains of how to find the linear range of the BET plot for microporous materials
in a way that reduces any subjectivity in the assessment of the monolayer capacity. This was
addressed by Rouquerol et al [52] who suggested a formal procedure based on the criteria that (1)
the quantity of C must be positive (i.e. any negative intercept on the ordinate of the BET plot is
89 of 158
Autosorb-6iSA/ASWin Operating Manual
G. DATA ANALYSIS USING ASWin
an indication that one is working outside the valid range of the BET equation) and (2) the
application of the BET equation is limited to the pressure range where the term n(P0 – P) or
alternatively n(1– P/P0) continuously increases with P/P0 (n is the adsorbed amount). This
procedure has been incorporated in ISO standard ISO/FDIS 9277:2010.
Figure G-16 shows the plot of n(Po – P) vs. P/Po for the argon adsorption isotherm at 87.3 K on
a faujasite zeolite. It is clearly visible that based on the second criterion above, only data points
below a relative pressure of 0.053 can be used for application of the BET calculation. The
resulting BET plot is shown in Figure G-17, i.e. the BET equation is applied for relative
pressures below about 0.053 down to 0.01, and a linear plot with positive C constant is obtained.
Range of points
to use for BET
calculations
Figure G-16, Plot of the term n(Po - P) vs. P/Po
Fit of data in the
traditional range of
BET equation has a
negative intercept
Fit of data using the low
pressure points as
described in the text has
a positive intercept
Figure G-17, BET plot for argon on a faujasite zeolite at 87K.
This method of tagging points in the linear range (that is to the left of the dotted line shown in
Fig G.15) is available in ASWin. To tag data points using this method click on Micropore BET
Assistant in the Edit data points dialog; a graph similar to that shown in will open up . All
adsorption data points will be shown, and the top 7 points (fewer if 7 are not available) in the
linear BET range will be automatically highlighted. To accept these as shown, click OK. An
alternative range can be selected by dragging the sliders to highlight more or fewer points, or a
different range altogether. The range can also be selected by entering minimum and maximum
P/Po values under the User Actions drop down menu. In that menu you can also set the indicated
range to those points already tagged in the standard manner in the Edit data points dialog.
90 of 158
Autosorb-6iSA/ASWin Operating Manual
G. DATA ANALYSIS USING ASWin
Select different
points using the
slide controls
The drop-down User Actions
menu allows you to enter the
range numerically and revert to
the automatic selection.
Figure G-18, Micropore BET Assistant automatically the top 7 points in the linear BET
range (as shown by the lighter shaded areas and the range sliders)
7.2.6
Langmuir Surface Area
Tags: L
If you want to calculate the Langmuir surface area for the sample, set the desired data points with
the L tag. Langmuir surface area tags are usually used in a range similar to the BET range but
not necessarily identical. The resulting Langmuir plot should be linear with a positive intercept.
7.2.7
Tags: T
t-plot: Statistical Thickness Methods
Linear t-plots correspond to the strictly multilayer region of the isotherm, i.e. after micropore
filling and monolayer coverage and before capillary condensation in mesopores. A useful
starting range is P/Po = 0.2 to 0.5 which can then be adjusted up or down as appropriate.
91 of 158
Autosorb-6iSA/ASWin Operating Manual
7.2.8
G. DATA ANALYSIS USING ASWin
alpha-s Method
Tags: T
For the alpha-s method calculation, you must first assign T tags to the appropriate data points.
Select a Standard Isotherm File from the pull-down list. Table G.3 lists the Standard Isotherm
Files available in the software. Finally, select the desired P/P0 value for the calculation.
7.2.9
MP Method
Tags: None
Click the t, MP, alpha-s group tab on the Data Reduction Parameters window to access
parameters for these methods:
Figure G-19, Setting parameters for t, MP, and alpha-s methods
For the t-plot method calculations, T tags must be set for the desired data points. Select and
check one option from de Boer, Carbon Black, Halsey, or Generalized Halsey for t-method
used. Note that the Carbon Black t-method calculation corresponds to ASTM D5816.
The MP method does not require data tags. Enter the value for the Thickness interval in its
field.
Table G.3 , Standard Isotherm Files for alpha-s Method.
alpha–s Standard Isotherm File
_asilar
_asil1
_acarb
Material / Experimental Conditions
Nonporous hydroxylated silica (argon at 77K)
Nonporous hydroxylated silica (nitrogen at 77K)
Nonporous carbon (nitrogen at 77K)
92 of 158
Autosorb-6iSA/ASWin Operating Manual
_aalum1
G. DATA ANALYSIS USING ASWin
Nonporous alumina (nitrogen at 77K)
7.2.10
FHH: Frenkel-Halsey-Hill Method
NK: Neimark Kiselev Method
Tags: R
These two methods constitute the Fractal Dimension calculations for the ASWin software. Both
of these methods can be used for the adsorption and/or desorption branches of the isotherm.
Assign R tags to the desired data points.
7.2.11
Total Pore Volume
Tags: V
The Total Pore Volume calculation can be found in the Tabular Data portion of the software.
Assign the V tag to the desired data point (usually the last adsorption data point in the isotherm).
7.2.12
Average Pore Size
Tags: V, M
The Average Pore Size calculation can be found in the Tabular Data portion of the software. For
the Average Pore Size calculation requires the calculation of the Multi-point BET surface area
(M tags) in addition to the V tag.
8
Kr-87 K Pore Size Analysis Method
This is a novel method for the pore size analysis of thin porous (siliceous, oxidic) films by
krypton adsorption at 87 K according to the method suggested by Thommes et al[51](for more
information about this method, contact application-sp@anton-paar.com). In the core
application range of this method, i.e. the pore diameter range between ca. 2.5 nm and 8 nm, the
obtained pore size data are traceable to NLDFT pore size data (please see the mentioned
references for more info on this). The wider application range of this Kr-87 K/thin film extends
from ca. 0.7 nm to up to 8 nm).
In order to apply this data reduction method on Kr/87 K adsorption isotherm data (as measured,
i.e. the experimental saturation pressure corresponds to the sublimation pressure of krypton at 87
K), the following steps need to be applied:
1
Open the data file in the ASWin software, version 2.0 or newer.
2
Selec“ "Krypton”7" as an adsorbate (see Section G.7).
3
Appl“ "P ta”s" to the adsorption data points (please note that the method is not applicable to
desorption data) you want to include in the pore size distribution (see Section G.6). Please
make sure not to include data from potential bulk sublimation transition (indicated by a steep
step in the isotherm close or at the saturation pressure).
4
Select Kr87 Pore Size Method (graph or table) and then display the pore size distribution,
preferably as dv(log r).
93 of 158
Autosorb-6iSA/ASWin Operating Manual
5
G. DATA ANALYSIS USING ASWin
A Total Pore volume can be obtained by adding “ "V tag” to the adsorption data in the
plateau-region of the isotherm (or the data points at the highest rel. pressure), and then by
choosin“ "total pore volu”e" from the tabular data menu.
9
Calculation of Isosteric Heats of
Adsorption
For the calculation the isosteric heat of adsorption on a sample you have to have previously
measured at least two isotherms at different temperatures on the same sample.
Figure G-20, Starting Heats of Adsorption Calculation
To perform the calculation click New on the File menu and then click Heats of Adsorption to
open the Heats of Adsorption window:
Figure G-21, Selecting files for heats of adsorption calculation.
94 of 158
Autosorb-6iSA/ASWin Operating Manual
G. DATA ANALYSIS USING ASWin
Click Add to open and add an isotherm file to the set of isotherms which you want to use for the
calculation of heats of adsorption. It is recommended to add the lowest temperature isotherm
first.
When you have opened at least two isotherms, you can click OK to perform the calculations.
This will display the results. An example of calculated heats of adsorption for hydrophobic
carbon sample is shown below. You can save the results under a new name.
Figure G-22, Sample heats of adsorption plot.
95 of 158
Autosorb-6iSA/ASWin Operating Manual
I. THEORY AND DISCUSSION
H. DATA PRESENTATION USING ASWin
After opening the file, setting the appropriate Tags for the data points, and setting the necessary
Data Reduction Parameters, the ASWin software can be used to construct graphical plots and
tables for the data. Tables and plots generated for a given data file can be accessed from the
Floating Menu (see Section G.4). To view the list of available graphs or tables, click Graphs or
Tables on the Floating Menu to open the respective submenu, then click the particular item
which you wish to access.
Figure H-1, Data File Floating Menu
If a plot or a table is selected and the Data Reduction Parameters and/or the appropriate Tags for
the calculation are not set properly, ASWin will display an error message.
Figure H-2, Example error message when required tags are not defined.
96 of 158
Autosorb-6iSA/ASWin Operating Manual
1
I. THEORY AND DISCUSSION
Interactive Modification of Tag Selection
When you view a plot or a table with the results of calculations obtained by a given method, you
may wish to change the number of data points used for that calculation.
To modify data tags for a given data file, right-click on an open plot or a table associated with
this file and activate the Floating Menu (see Section G.4). Click Edit data tags to open the Edit
Data Points window (see Section G.6); add or remove appropriate tags in this window.
Click OK when you are finished. This will automatically update all the open plots and tables
related to the modified data.
To help you make appropriate modifications in the tag selection the software enables you to
show (or hide) data points for a given plot.
For example, the plot shown below is a t-plot for a microporous sample. As a general guideline,
the linear region for the t-method calculation is typically between 0.2 and 0.5 P/P0. However, it
may extend to higher or lower relative pressures.
All adsorption points
(marker: open circles)
Tagged data points for
the calculation
(marker: filled circles)
Use the legend buttons to hide
(shaded)/show data sets
Only the checked
data set sets will
appear in the plot.
Best fit line
Figure H-3, Viewing graphically which points used in calculations.
97 of 158
Autosorb-6iSA/ASWin Operating Manual
2
I. THEORY AND DISCUSSION
Configuring Graph Properties
You can modify features of the graphs using the Configure Graph Properties
window:
Figure H-4, Customizing the look of the graph.
You can access this window in two ways:
• Click Display Properties on the Configure menu, and then click Graph Properties on the
submenu.
• Click Graph Properties on the Floating Menu.
Graphing properties can be set for every plot that is generated by the software. Each plot may
have different settings such as x- and y-axis values, data point marker style, graph colors, and
line thickness. To set these values for the individual plots, locate the method in the Graph
Properties Tree (Figure H-5, Configuring graph properties.).
98 of 158
Autosorb-6iSA/ASWin Operating Manual
I. THEORY AND DISCUSSION
As an example, the V-t plot
can contain the following data
sets (curves):
A: selected Adsorption points
D: selected Desorption points
all A: all Adsorption points
all B: all Desorption points
BF: best fit line for data set
Click the + sign
to expand the
list of plots for
the method.
Click the – sign
to hide the list.
Figure H-5, Configuring graph properties.
Select a graph or graph curve from the list on the left. Graphs are grouped, usually by the method
by which they are generated. Click on the + sign to expand nodes, or on the – sign to collapse an
open one. The selected (active) item (i.e. the one for which you are setting the properties) is
highlighted.
When a graph is selected, graph line properties cannot be changed (grayed out). When a graph
line is selected, the graph properties of the graph to which the line belongs can still be adjusted.
For quick copying of properties, use the copy/paste buttons. Their effect depends on whether
they are applied to graphs or lines. Click Copy to mark the currently selected item as the source,
select the target, and click Paste to copy the properties of the source to the target. Source and
target must be the same type of node — only graph-to-graph or line-to-line copies are allowed. If
there is no proper source selection made, the paste button is grayed.
For lines, the color and marker selections are copied.
For graphs, all graph specific properties as well as a list of line properties is copied. If the target
has more lines than the source, the lines that have no matching counterparts will be reset to
default values (black line with no marker). If the source has more lines, the excess line property
data are ignored.
Click Save to store the current settings to permanent storage — otherwise the changes made will
be lost when the program is closed.
Click OK to return to the main window of the program, and apply all changes made.
Click Cancel to discard all changes made in this window.
99 of 158
Autosorb-6iSA/ASWin Operating Manual
3
I. THEORY AND DISCUSSION
Configuring Table Properties
To change the appearance of tables displayed on the screen or printed, select
Configure>>Display Properties>> Table Properties from the main menu. This will open the
Tabular View Properties window shown in Figure H-6. The font may be selected from the pulldown list in the Use font field, or click on Select Font to open a dialog to set the font and font
properties. The size of the screen display and margins may also be set.
Figure H-6, Changing the appearance of tables.
Figure H-7, Selecting font for tables.
100 of 158
Autosorb-6iSA/ASWin Operating Manual
4
I. THEORY AND DISCUSSION
Creating Overlay Plots
The ASWin software allows you to overlay graphs of data and results from different files. An
overlay can be made for any plot type available in the software; right-click on the already open
plot to bring up the Floating Menu. Click Overlay to create the root overlay plot
<unnamed.OVP> - a copy of the original plot but one to which you can add graphs generated
from different data file(s). Right-clicking on this root plot dispalys a new Floating Menu.
Figure H-8, Floating menu for overlay plots.
Click Manage on this menu to access the Overlay Manager window:
Highlight a filename
then click the Descr.
button to enter a longer
description than
allowed by the label.
Figure H-9, Overlay manager for adding and removing plots.
Click Add and select the appropriate file from the list in the Open window, then click Open.
Finally, enter the display label for the added data in the Enter Value field (see Figure H-10),
click OK, and view the overlay plot.
Figure H-10, Enter a label to identify the curves associated with this data file.
101 of 158
Autosorb-6iSA/ASWin Operating Manual
I. THEORY AND DISCUSSION
Figure H-11. Sample overlay plot.
If you wish to change the graph properties, right-click on the graph, and then click Graph
Properties on the Floating Menu. This will open the Configure Graph Properties window.
Locate Overlays on the tree and follow the procedure described in the previous section.
Overlay graphs
Select the Line that
you wish to
configure the graph
properties. A total of
16 lines (overlays)
are permitted.
Figure H-12, Configuring the graph properties for specific lines.
102 of 158
Autosorb-6iSA/ASWin Operating Manual
I. THEORY AND DISCUSSION
To change the label or description of a file, select the file from the list in the Overlay Manager
window and click Label or Descr. To remove a file from the graph select it on the list and click
Remove.
To save the overlay graph click Save As in the File menu. The graph will be saved under a new
name in the Auxiliary Data folder.
You can also start the overlay procedure directly, that is without a plot already open on screen;
click New on the File menu and then Physisorption Overlay:
Figure H-13, Creating a physisorption overlay.
Open the first file from the standard Open window as the root; it will open up and display as the
isotherm graph. Proceed to add the next isotherm as already described above. Once an overlay
plot has been created, you can change the type of plot, for example to multi-point BET, or BJH
adsorption, without having to start over adding data files one-by-one. Simply select another plot
type via the right click (floating menu) graphs menu. (the original overlay remains open). Any
missing calculation tags or incompatible settings will cuase pop-up warning messages indicating
the problem.
You can access and modify the Data Reduction Parameters for the overlay plot by highlighting a
file and clicking the DRP button on the Overlay Manager window.
You can also synchronize Data Reduction Parameters for all overlay plots by clicking Synch
on the Overlay Manager window.

NOTE! When you Save an Overlay file you are creating a *.ovp file that contains
only a list of the source files used in the overlay plot. The *.ovp file does not
contain the data itself, or a copy of the files, and so cannot easily be usefully
exported to and opened on a different PC. Similarly if any one of the source
files is renamed, the opening the Overlay *.ovp file will fail.
103 of 158
Autosorb-6iSA/ASWin Operating Manual
5
I. THEORY AND DISCUSSION
Generating Custom Reports
To generate custom reports, click Manage Reports on the Configure menu. This activates the
Report Manager window shown in Figure H-14.
The files listed in this window were saved during the software installation. The list includes
seven sample report files (titled “demo.XXX”), which you may use or edit. To modify an
existing report file, highlight the file name and click Edit. You may also create your own report
file by clicking New on this window. To remove unwanted report file, highlight its name and
click Delete.
These demo report files
are automatically
installed with the
software. You may use
or edit these files for
custom reports
Figure H-14, Defining and modifying reports.

NOTE! Deleting a report file is an irreversible action. Once a report file has been
deleted, it cannot be retrieved.
Click New on the Report Manager window to generate a custom report. A window will appear
prompting you to enter a filename for the report that you wish to create.
Figure H-15, giving a new report a unique name.
Enter the filename click OK. The following Report Editor window will appear:
104 of 158
Autosorb-6iSA/ASWin Operating Manual
I. THEORY AND DISCUSSION
Click the “+” sign to
display the individual
graphs, tables, metadata,
and/or formatting options.
Highlight an
element and
click Add
Figure H-16, Editing/creating a report.
Choose the desired combination of graphs, tables, metadata (data reduction parameters and
calculation method summaries), and formatting options from the right-hand window. Highlight
your selection and click Add. Your selections will appear in the left-hand space. To change the
printing order for the report, highlight the selection and click the “↑” or “↓” buttons. Click Del to
remove the selection from the report. Click OK when you are finished:
Select the size of the printed
selection here. Available choices
are full, 1/2, and 1/3 page. Note
that these sizes refer to the
printout size of the whole page
minus the header
Use arrows to move
selection up or down
Figure H-17, Editing a report.
The custom report can be assigned to a data file before the measurement by requesting the report
to be automatically printed at the end of the analysis (for details, see Section F.3.5).
To assign the custom report to the open data file, activate the Floating Menu (see Section G.4),
click Reports on this menu and click the appropriate report on the submenu. When a report is
assigned to the data file, all graphs, tables, and metadata (data reduction parameters and
105 of 158
Autosorb-6iSA/ASWin Operating Manual
I. THEORY AND DISCUSSION
calculation method summaries) will be produced by the software. The title of the window will
appear as “reprt:report file name: data file name”.

NOTE! Make sure that you have correctly assigned the necessary data reduction
tags for the models that will be contained in the report. If this is not done
prior to selecting the report, an error message will appear prompting you to
add the required data reduction tags.
Click this button to
scroll through the
individual graphs
and tables in the
report.
Figure H-18, Viewing the various graphs and tables in a report
6
Modifying Custom Reports
To create or modify custom reports, use this window:
Figure H-19, Report Design
106 of 158
Autosorb-6iSA/ASWin Operating Manual
I. THEORY AND DISCUSSION
On the left side, the current contents of the report are displayed with (optional) parameters.
Select one or more items using the Windows enhanced selection method. Selected items can be
moved up or down using the arrow buttons below the list box. If a noncontiguous selection is
moved, it will be made continuous upon the move.
Click on the Del button to remove the selected items from the report.
The icon on the left of the entry indicates the type of the item (see groups below).
The Graph shows a size selection item and the options are:
• Full page
• 1/2 page
• 1/3 page
These sizes refer to the printout size of the whole page minus the header.
On the right hand side the available report items are listed in a hierarchical view. Click on the +
sign to expand the node next to it.
The logical groups of items are as follows:
Graphs
available graph items further grouped by the calculation methods
Tables
tabular data lists (grouped by calculation method)
Meta data
additional text data. Including calculation result summaries, data reduction
parameters and analysis parameters
Formatting
items used to format the report, currently the only formatting supported is
a page break that forces a new page in the report printout.
Click on the Add button to append the selected item to the end of the report.
Use the OK button to accept the changes, Cancel to discard them, and return to the Report
Manager.
7
Saving Tables as Text
Any table can be saved as text. Right click on the table and then click on Save as Text at the
bottom of the floating menu. This will open a Name File window with “Exports” as default
folder.
Figure H-20, Saving a table as a text file
107 of 158
Autosorb-6iSA/ASWin Operating Manual
8
I. THEORY AND DISCUSSION
Changing Header Information
The following is an example of a report header on a typical printout:
If you wish to insert a company
logo in the header, it will
appear here. The logo will
appear only on the printout (not
on-screen).
This part of the Header
may be changed.
To change the information at the top of the Header that is displayed on each printed page of the
report, click Display Properties on the Configure menu, and then click Report Header Properties
on the submenu. This will activate the following window:
Click here to enter a
graphics file for the
company logo.
Click here to
remove the logo.
Enter custom
header text here.
Figure H-21, Modifying header text and adding a company logo.
Enter the header in the Header Text field (3 lines max). Click OK when finished.
When the new text is added, “Quantachrome ASWin © 1994-2013, Quantachrome
Instruments v2.0X” will remain at the bottom of the Header. To restore the default text for this
portion of the Header, open the Report Header Properties window and delete the text. Click
OK and the default text will appear.
To add a custom logo to the header, click the browse button (…) and use the file open dialog to
locate and open a graphics file with the logo. Click OK when finished.
Figure H-22, Example of a modified header.
108 of 158
Autosorb-6iSA/ASWin Operating Manual
I. THEORY AND DISCUSSION
I. THEORY AND DISCUSSION
This section contains an overview of the theories on which the Autosorb-6iSA is based. It is
intended to give the reader a basic understanding of adsorption chemistry and how it is used to
characterize powders and porous materials. It is not intended to be a comprehensive treatise on
the subject. For a more in-depth treatment of the subject, the reader is referred to
“Characterization of Porous Solids and Powders: Surface Area, Pore Size, and Density” [41. .
1
Surface Area
The Brunauer-Emmett-Teller (BET) method [1] is the most widely used procedure for the
determination of the surface area of solid materials and involves the use of the BET equation
(I.1):
1
1
C -1  P 
=
+
 
W ( ( P0 / P ) - 1 ) W m C W m C  P0 
(I.1)
where, W is the weight of gas adsorbed at a relative pressure, P/P0, and Wm is the weight of
adsorbate constituting a monolayer of surface coverage. The term C, the BET C constant, is
related to the energy of adsorption in the first adsorbed layer and consequently its value is an
indication of the magnitude of the adsorbent/adsorbate interactions.
1.1 Multipoint BET Method
The BET equation (I.1) requires a linear plot of 1/[W(P0/P)–1] vs. P/P0 which for most solids,
using nitrogen as the adsorbate, is restricted to a limited region of the adsorption isotherm,
usually in the P/P0 range of 0.05 to 0.30. This linear region is shifted to lower relative pressures
for microporous materials. A typical BET plot is shown in Figure I-1:
Figure I-1 , Typical BET Plot
The standard multipoint BET procedure requires a minimum of three points in the appropriate
relative pressure range. See Section G.7.2.5 for proper point selection. The weight of a
109 of 158
Autosorb-6iSA/ASWin Operating Manual
I. THEORY AND DISCUSSION
monolayer of adsorbate Wm can then be obtained from the slope s and intercept i of the BET
plot. From equation (I.1):
s=
C -1
W mC
(I.2)
1
(I.3)
and
i=
W mC
Thus, the weight of a monolayer Wm can be obtained by combining equations (I.2) and (I.3):
Wm =
1
s+i
(I.4)
The second step in the application of the BET method is the calculation of the surface area. This
requires knowledge of the molecular cross-sectional area Acs of the adsorbate molecule. The total
surface area St of the sample can be expressed as:
St =
W m N Acs
M
(I.5)
where N is Avogadro’s number (6.0221415 × 1023 molecules/mol) and M is the molar mass
(molecular weight) of the adsorbate. Nitrogen is the most widely used gas for surface area
determinations since it exhibits intermediate values for the C constant (50–250) on most solid
surfaces, precluding either localized adsorption or behavior as a two dimensional gas. Since it
has been established [2. 3. ] that the C constant influences the value of the cross-sectional area
of an adsorbate, the acceptable range of C constants for nitrogen makes it possible to calculate its
cross-sectional area from its bulk liquid properties. For the hexagonal close-packed nitrogen
monolayer at ~77 K, the cross-sectional area Acs for nitrogen is 16.2 Å2.
The specific surface area S of the solid can be calculated from the total surface area St and the
sample weight w, according to equation (I.6):
(I.6)
S = St / w
1.2 Single Point BET Method
For routine measurements of surface areas, a simplified procedure may be applied, using only a
single point on the adsorption isotherm in the linear region of the BET plot. For nitrogen, the Cvalue is usually sufficiently large to warrant the assumption that the intercept in the BET
equation is zero. Thus, the BET equation (I.1) reduces to:
(I.7)
W m = W (1 - P / P0 )
By measuring the amount of nitrogen adsorbed at one relative pressure (preferably near P/P0 =
0.3) the monolayer capacity Wm can be estimated using equation (I.7) and the ideal gas equation.
That is:
Wm =
PV M
( 1 - P / P0 )
RT
(I.8)
110 of 158
Autosorb-6iSA/ASWin Operating Manual
I. THEORY AND DISCUSSION
The total surface area then can be obtained from equation (I.5). That is:
St =
P V N Acs (1 - P / P0 )
RT
(I.9)
1.3 Multipoint/Single Point Comparison
The relative error introduced by the single point versus the multipoint method for determining
surface area is a function of the BET C constant and the relative pressure used. The magnitude of
the error in the single point method can be determined from a comparison of the monolayer
weight obtained from the BET equation (I.1) and the single point equation (I.7). Solving
equation (I.1) for Wm gives:
C -1 P  
  1
 P0
-1   +


Wm = W 
C  P0  
 C
 P
Rewriting the single point equation (I.7), gives:
W ′ = W [ ( P0 / P ) - 1 ] P / P0
(I.10)
(I.11)
The relative error inherent in the single point method, then, is:
1 - P / P0
W m - W m′
=
1 + [ P / P0 ( C - 1 ) ]
Wm
(I.12)
Equation (I.12) indicates that for a given C value, the relative error decreases with increasing
relative pressure. Therefore, a relative pressure as high as possible, yet still in the linear region of
the BET plot, should be chosen for single point surface area determinations. For all except
microporous samples a P/P0 of about 0.3 is preferable. For single point determinations on
microporous samples a relative pressure as high as possible on the linear BET plot should be
chosen.
(I.13)
C = ( s / i )+ 1
Table I.1 gives the relative error for various C values calculated from equation (I.13) using P/P0
of 0.3. Table I.1, Single Point BET Error.
Single Point/ Multipoint Comparison
C Constant
Relative Error%
1
70
10
19
50
4
100
2
1000
0.2
∞
0
111 of 158
Autosorb-6iSA/ASWin Operating Manual
I. THEORY AND DISCUSSION
Prior to using the single point method for the determination of surface area, the C constant can be
evaluated from a multipoint BET plot. That is, where s and I are the slope and y-intercept,
respectively, of the BET plot. Subsequently, the single point method can be used on materials
having the same composition. For greater accuracy, if the C constant is known, the single point
result may be corrected using equation (I.12).
112 of 158
Autosorb-6iSA/ASWin Operating Manual
2
I. THEORY AND DISCUSSION
Pore Size by Gas Adsorption
It is expedient to characterize pores according to their sizes:
a) The term “micropores” describes pores with diameters not exceeding 2nm (20 Å).
b) Pores of between 2 – 50nm (20–500 Å) are called “mesopores.”
c) Pores with openings exceeding 500 Å in diameter are called “macropores.”
Pore volume and pore size of porous solids can be conveniently characterized by gas adsorption
measurements. The evaluation of pore size distribution on the Autoosrb-6iSA is most
conveniently accomplished using nitrogen adsorbate at 77 K (liquid nitrogen temperature). Pore
size distributions are calculated from complete isotherms, that is adsorption and desorption data
across as wide a range of P/Po as is practicable.
3
Adsorption-Desorption Isotherms
Based upon an extensive literature survey, performed by Brunauer, Demming, Demming,
and Teller (BDDT)[4. ], the IUPAC published in 1985 a classification of six sorption
isotherms[42. ]. The appropriate IUPAC classification is shown in
Figure I-2. Each of these six isotherms and the conditions leading to its occurrence are now
discussed according to Sing et al[42. ].
3.1 Isotherm Types
Type I: This fully reversible type is concave to the P/P0 axis and the adsorbed amount
approaches a limiting value as P/P0→1. Type I isotherms are obtained when adsorption is
limited to, at most, only a few molecular layers. In the case of physisorption, isotherms obtained
on microporous materials are often of type I. Micropore filling and therefore high uptakes are
observed at relatively low pressures, because of the narrow pore width and the high adsorption
potential. The limiting uptake is being governed by the accessible micropore volume rather than
by the internal surface area. This behavior is also encountered in chemisorption, where the
asymptotic approach to a limiting quantity indicates that all of the reactive surface sites are
occupied.
Type II: These reversible sigmoidal isotherms are typically obtained in case of non-porous or
macroporous adsorbents, where unrestricted monolayer-multilayer adsorption can occur. The
inflection point or knee of the isotherm is called point B. This point indicates the stage at which
monolayer coverage is complete and multilayer adsorption begins to occur.
Type III: This uncommonly encountered isotherm is convex to the P/P0 axis over its entire
range and therefore does not exhibit a point B. This indicates that the attractive adsorbateadsorbent interactions are relatively weak and that the adsorbate-adsorbate interactions play an
important role. One example of this relatively rar113vaporator is nitrogen adsorption on
polyethylene or the adsorption of water vapor on the clean basal plane of graphite.
Type IV: A sigmoidal isotherms with open hysteresis is typical of a mesoporous material. The
most characteristic feature is the hysteresis loop which is associated with the occurrence of pore
condensation. Any limiting uptake over a range of high P/P0 which results in a plateau of the
113 of 158
Autosorb-6iSA/ASWin Operating Manual
I. THEORY AND DISCUSSION
isotherm, indicates complete pore filling. The initial part of the type IV can be attributed to
monolayer-multilayer adsorption just as in case of the type II isotherm.
Figure I-2, IUPAC classification of sorption isotherms[42].
Type V: These isotherms show pore condensation and hysteresis similar to type IV, however
the initial part of this isotherm is the same as the adsorption behavior seen in type III, indicating
relatively weak attractive interactions between the adsorbent and the adsorbate. Yet this does not
prevent pores filling and emptying via condensation an114vaporationon processes – hence the
hysteresis.
Type VI: A special case representing disnticnt stepwise multilayer adsorption on a uniform, nonporous surface[43. ], particularly by spherically symmetrical, non-polar adsorptives (for
example krypton on graphite). The sharpness of the steps depends on the homogeneity of the
adsorbent surface, the adsorptive, and the temperature.
3.2 Hysteresis Types
It is widely accepted that there is a correlation between the shape of the hysteresis loop and the
texture (e.g., pore size distribution, pore geometry, connectivity) of a mesoporous adsorbent. An
empirical classification of hysteresis loops was given by IUPAC[43. ], which is based on an
earlier classification by de Boer[5. ].
114 of 158
Autosorb-6iSA/ASWin Operating Manual
I. THEORY AND DISCUSSION
Amount Adsorbed
The IUPAC classification is shown in Error! Reference source not found..
H1
H2
H3
H4
Relative pressure
Figure I-3, IUPAC classifications of hysteresis loops.
According to the IUPAC classification, type H1 is often associated with porous materials
consisting of well-defined cylindrical-like pore channels or agglomerates of compacts of
approximately uniform spheres. It was found that materials that give rise to H2 hysteresis are
often disordered and the distribution of pore size and shape is not well defined. Isotherms
revealing type H3 hysteresis do not exhibit any limiting adsorption at high P/P0, which is
observed with non-rigid aggregates of plate-like particles giving rise to slit-shaped pores. The
desorption branch for type H3 hysteresis contains also a steep region associated with a (forced)
closure of the hysteresis loop, due to the so-called tensile strength effect. This phenomenon
occurs for nitrogen at 77 K in the relative pressure range from 0.4 – 0.45. Similarly, type H4
loops are also often associated with narrow slit pores, but now including pores in the micropore
region.
The dashed curves in the hysteresis loops shown in Error! Reference source not found. reflect
low-pressure hysteresis, which may be observable down to very low relative pressure. Lowpressure hysteresis may be associated with the change in volume of the adsorbent, i.e. the
swelling of non-rigid pores or with the irreversible uptake of molecules in pores of about the
same width as that of the adsorptive molecule. In addition, chemisorption will also lead to such
“open” hysteresis loops. An interpretation of sorption isotherms showing low-pressure hysteresis
is difficult and an accurate pore size analysis is not possible. But the hysteresis loops usually
associated with pore condensation also imposes a difficulty on the pore size analysis: should the
115 of 158
Autosorb-6iSA/ASWin Operating Manual
I. THEORY AND DISCUSSION
adsorption or desorption branch be taken for calculation of the pore size distribution curve. This
depends very much on the reason(s) which caused the hysteresis [41. ].
3.3 Total Pore Volume and Average Pore Radius
The total pore volume is derived from the amount of vapor adsorbed at a relative pressure close
to unity, by assuming that the pores are then filled with liquid adsorbate. For a discussion of the
relationship between pore size and relative pressure, see Section I.3.4. If the solid contains no
macropores, the isotherm will remain nearly horizontal over a range of P/P0 approaching unity
and the pore volume is well defined. However, in the presence of macropores the isotherm rises
rapidly near P/P0 = 1 and in the limit of large macropores may exhibit an essentially vertical rise.
In this case, the limiting adsorption can be identified reliably with the total pore volume
assuming careful temperature control of the sample. The volume of nitrogen adsorbed (Vads) can
be converted to the volume of liquid nitrogen (Vliq) contained in the pores using equation (I.14).
That is,
V liq =
P a V ads V m
RT
(I.14)
in which Pa and T are ambient pressure and temperature, respectively, and Vm is the molar
volume of the liquid adsorbate (34.7 cm3/mol for nitrogen).
Since pores which would not be filled below a relative pressure of 1 have a negligible
contribution to the total pore volume and the surface area of the sample, the average pore size
can be estimated from the pore volume. For example, assuming cylindrical pore geometry (type
H1 hysteresis), the average pore radius rp can be expressed as:
r p =
2 V liq
S
(I.15)
where Vliq is obtained from equation (I.14) and S is the BET surface area. For other pore
geometries a knowledge of the shape of the hysteresis in the adsorption/desorption isotherm is
required.
3.4 Pore Size Distributions (Mesopore)
The distribution of pore volume with respect to pore size is called a pore size distribution. It is
generally accepted that the desorption isotherm is more appropriate than the adsorption isotherm
for evaluating the pore size distribution of an adsorbent. The desorption branch of the isotherm,
for the same volume of gas, exhibits a lower relative pressure, resulting in a lower free energy
state. Thus, the desorption isotherm is closer to true thermodynamic stability. In certain cases, for
example, samples exhibiting type H2 hysteresis, the adsorption isotherm is recommended for
pore size distribution determinations. The ASwin software offers the capability of using either
branch of the isotherm for the calculation. Since nitrogen has been used extensively in gas
adsorption studies, it has been well characterized and serves as the most common adsorbate for
pore size distribution measurements. Therefore, the following discussion will apply to the use of
nitrogen as the adsorbate.
Mesopore size calculations are made assuming cylindrical pore geometry using the Kelvin
equation (I.16) in the form
116 of 158
Autosorb-6iSA/ASWin Operating Manual
rK =
I. THEORY AND DISCUSSION
-2γ Vm
R T ln ( P / P0 )
(I.16)
where:
γ = the surface tension of nitrogen at its boiling point (8.85 ergs/cm2 at 77 K).
Vm = the molar volume of liquid nitrogen (34.7 cm3/mol).
R = gas constant (8.314x107 ergs/deg/mol).
T = boiling point of nitrogen (77 K).
P/P0 = relative pressure of nitrogen.
rK = the Kelvin radius of the pore.
Using the appropriate constants for nitrogen, equation (I.16) reduces to
t (Å) =
4.15
log(P0 / P )
(I.17)
The Kelvin radius rK is the radius of the pore in which condensation occurs at a relative pressure
of P/P0. Since, prior to condensation, some adsorption has taken place on the walls of the pore, rK
does not represent the actual pore radius. Conversely, during desorption an adsorbed layer
remains on the walls when evaporation occurs. The actual pore radius rp is given by:
(I.18)
r p = rk + t
where t is the thickness of the adsorbed layer. This statistical t can be considered as 3.54
(Vads/Vm) in which 3.54 Å is the thickness of one nitrogen molecular layer and Vads/Vm is the
ratio of the volume of nitrogen adsorbed at a given relative pressure to the volume adsorbed at
the completion of a monolayer for a nonporous solid of the same composition as the porous
sample. A more convenient method for estimating t was proposed by de Boer[6. ] in the form of
equation (I.19) and is accessible for pore size distribution calculations in the ASWin software.


13.99
t (Å) = 

 log(P0 / P ) + 0.034 
1/ 2
(I.19)
Other expressions for t calculations, available through the ASWin software, are presented in the
Section I.4.
ASWin computes the pore size distribution using the methods proposed by Barrett, Joyner, and
Halenda[7. ] (BJH) and by Dollimore and Heal[8. ] (DH) as described in the following sections.
3.4.1
BJH Method
Assuming that the initial relative pressure (P/P0)1 is close to unity, all pores are filled with liquid.
The largest pore of radius rp1 has a physically adsorbed layer of nitrogen molecules of thickness
t1. Inside this thickness is an inner capillary with radius rK from which evaporation takes place as
P/P0 is lowered. The relationship between the pore volume Vp1 and the inner capillary (Kelvin)
volume VK is given by:
V p1 = V K1 r p1 / r K1
2
2
(I.20)
117 of 158
Autosorb-6iSA/ASWin Operating Manual
I. THEORY AND DISCUSSION
When the relative pressure is lowered from (P/P0)1 to (P/P0)2 a volume V1 will desorb from the
surface. This liquid volume V1 represents not only emptying of the largest pore of its condensate
but also a reduction in the thickness of its physically adsorbed layer by an amount Δt1. Across
this relative pressure decrement the average change in thickness is Δt1/2. The pore volume of the
largest pore may now be expressed as:


r p1

V p1 = V 1 
 r K1 + ∆ t 1 / 2 
2
(I.21)
When the relative pressure is again lowered to (P/P0)3 the volume of liquid desorbed includes not
only the condensate from the next larger size pores but also the volume from a second thinning
of the physically adsorbed layer left behind in the pores of the largest size. The volume Vp2
desorbed from pores of the smaller size is given by:


r p2

V p2 = 
 r K2 + ∆ t 2 / 2 
2
( V 2 - V ∆t )
(I.22)
2
An expression for VΔt2 is:
V ∆t 2 = ∆ t 2 Ac1
(I.23)
where Ac1 is the area exposed by the previously emptied pores from which the physically
adsorbed gas is desorbed. Equation (I.23) can be generalized to represent any step of a stepwise
desorption by writing it in the form:
n -1
V ∆t n = ∆ t n ∑ Ac j
(I.24)
j=1
The summation in equation (I.24) is the sum of the average area in unfilled pores down to, but
not including, the pore that was emptied in the desorption. Substituting the general value for VΔt2
into equation (I.22) results in an exact expression for calculating pore volumes at various relative
pressures.
2
n -1


 
r pn
  ∆ V n - ∆ t n ∑ Ac j 
V pn = 
j=1
 r Kn + ∆ t n / 2  

(I.25)
Since the area (Ac) for any one size empty pore is not a constant but varies with each decrement
of P/P0, this term must be evaluated.
The area of each pore Ap is a constant and can be calculated from the pore volume, assuming
cylindrical pore geometry. That is:
Ap =
2 Vp
rp
(I.26)
Then the pore areas can be cumulatively summed so that for any step in the desorption process
Ap is known. The BJH method offers a means of computing ∑Acj from Ap for each relative
pressure decrement as follows…
118 of 158
Autosorb-6iSA/ASWin Operating Manual
I. THEORY AND DISCUSSION
It is assumed that all pores emptied of their condensate during a relative pressure decrement have
an average radius _r p calculated from the Kelvin equation (I.16) radii at the upper and lower
values of P/P0 in the desorption step. The average capillary (core) radius is expressed as:
(I.27)
=
- tr
rc
rp
where t − is the thickness of the adsorbed layer at the average radius in the interval in the current
r
pressure decrement and is calculated from equation (I.19).
The term “c” in equation (I.24) then is given by:
c = rc =
rp
r p - tr
(I.28)
rp
Equation (I.25) now can be used in conjunction with equation (I.28) as an exact expression for
the computation of pore size distributions.
3.4.2
DH Method
A computationally simpler approach to evaluating mesopore size distributions was developed by
Dollimore and Heal[8. ]. The DH approach differs from the BJH method in that the term V ∆t n in
equation (I.24) is calculated from:
(I.29)
V = ∆ t Σ A - 2π t ∆ t Σ L
p
n
∆t n
n
n
p
where, the summations ΣAp and ΣLp represent the areas and lengths, respectively, of all the pores
emptied of condensate in previous desorption steps. Assuming cylindrical pore geometry, the
cumulative pore areas and lengths can be estimated for each desorption step by summing the
expressions:
Ap =
2 Vp
rp
cf Eq. (I.26)
and
Lp =
Ap
2π rp
(I.30)
respectively.
3.5 Surface Area of Microporous Samples by Langmuir Method
In the absence of meso and/or macropores, a sample containing micropores will exhibit a Type I
or Langmuir isotherm (see Section I.3). The Langmuir equation (I.31) is a limiting case of the
BET equation (I.1) for the adsorption of a single molecular layer of adsorbate:
W
Wm
=
C ( P / P0 )
1 + C ( P / P0 )
(I.31)
W and Wm are the weight of adsorbate at some P/P0 and the weight in a monolayer, respectively.
C is a constant associated with the energy of adsorption. Equation (I.31), rewritten in the form of
a straight line:
119 of 158
Autosorb-6iSA/ASWin Operating Manual
I. THEORY AND DISCUSSION
P / P0
1
P / P0
=
+
W
CW m
Wm
(I.32)
allows the determination of the slope (1/Wm) from a plot of (P/P0)/W versus P/P0.
The weight of a monolayer Wm may then be used to calculate the total surface area of the sample
from equation (I.5). This method is not applicable to composite materials containing micropores
and meso- and/or macropores.
4
Micropore Analysis
Several different approaches to micropore analysis are available using ASWin. While no single
treatment is applicable to all situations, enough flexibility is provided for the user to select the
analysis most suitable for a given situation or material.
4.1 V-t Method
The ASWin software uses the t-method of Halsey[9. ], the generally preferred one of de
Boer[10. ](also known as Harkins-Jura) or the Carbon black (STSA) method[11. ]for the
determination of micropore volume in the presence of mesopores. This technique involves the
measurement of nitrogen adsorbed by the sample at various low-pressure values. The procedure
is the same as that employed in the BET surface area measurement, but it extends the pressure
range to higher pressures to permit calculation of the matrix or external surface area, that is, the
non-microporous part of the material. A t-plot is a plot of the volume of gas adsorbed versus t,
the statistical thickness of an adsorbed film.
In the ASWin software, the t values are calculated as a function of the relative pressure using
either the de Boer equation:


13.99
t (Å) = 

 log ( P0 / P ) + 0.034 
1/2
cf. (I.19)
the Carbon Black equation:
t CB ( Å ) = 0.88 ( P / P0 ) + 6.45 ( P / P0 ) + 2.98
2
(I.33)
or the Halsey equation which, for nitrogen adsorption at 77 K can be expressed as:


5
t ( Å ) = 3.54 

 2.303 log (P0 / P )
1/3
(I.34)
or in a generalized form (found useful for other adsorbates and/or temperatures) as:


1
t(Å) = a 

 ln (P 0 / P ) 
1/b
(I.35)
Where the pre-exponential term, a , and the exponential term, b , are 6.0533 and 3.0 for nitrogen
adsorption at 77 K, respectively.
120 of 158
Autosorb-6iSA/ASWin Operating Manual
I. THEORY AND DISCUSSION
Typical t-plots are shown in Figure I-4, Figure I-5, and Figure I-6 below, representing various
possible pore sizes. First t-plot of a sample having no micropores, as evidenced by the ability to
extrapolate the line to the origin, since the slope represents the total surface area St of all the
pores, that is:
St =
STP
(15.47)
Vads
t(Å)
(I.36)
VADS
STP
STP
where V ads
is the volume of gas adsorbed, corrected to standard conditions of temperature and
pressure, and the constant 15.47 represents the conversion of the gas volume to liquid volume.
0
1
2
3
4
5
6
7
t(Å)
Figure I-4, t-Plot of a mesoporous material
121 of 158
I. THEORY AND DISCUSSION
VADS
STP
Autosorb-6iSA/ASWin Operating Manual
0
1
2
3
4
5
6
7
t(Å)
Figure I-5, t-Plot of a microporous sample
STP
VADS
C
B
A
0
1
2
3
4
5
6
7
t(Å)
Figure I-6, t-Plot of a microporous material
Using the slope, s, of the t-plot (as shown) above, equation (I.36) reduces to:
S t ( m /g ) = s x 15.47
2
(I.37)
In the absence of micropores, there is good agreement between the t-area, St, and the surface area
determined by the BET method.
When micropores are present, the t-plot will exhibit a positive intercept. T-Plots for two types of
microporous materials are shown in Figure I-5 and Figure I-6. Figure I-5 is a t-plot of a sample
122 of 158
Autosorb-6iSA/ASWin Operating Manual
I. THEORY AND DISCUSSION
with pore openings smaller than 7–8 Å in diameter. Quantitative pore volume data from t-plots
cannot be obtained below t=3.5 Å, corresponding to pores smaller than 7 Å wide, since this t
value represents the diameter of a nitrogen molecule. The intercept, I, in the t-plot, when
converted to a liquid volume, gives the micropore volume, VMP. That is:
(I.38)
= i x 0.001547 ( 3 )
V MP
cm
The two linear regions of the t-plot in Figure I-6 indicate the presence of micropores larger than
7 Å and the actual pore width (2t) can be estimated at the position where the two linear plots
intersect. The slope of the upper linear portion (B) of the t-plot in Figure I-6 gives the mesopore
surface area using equation (I.34), while the slope of the lower linear portion (A) represents the
total surface area of all pores. Point C indicates the presence of micropores of about 10Å width
(2t).
(I.39)
- S
S = S
MP
BET
t
The linear BET region for microporous materials generally occurs at relative pressures less than
0.1. The linear t-plot range will be found at higher relative pressures and is dependent on the size
distribution of micropores. The micropore surface area, SMP, then, is the difference between the
BET surface area and the external surface area from the t-plot.
4.2 Alpha-s (αs) Method
An empirical analogue to the t-method was proposed by Sing[12. ], who pointed out that
comparing a given isotherm to a standard curve does not require invoking the concept of a
statistical thickness, t (which in turn depends on the BET surface area of nonporous reference
materials, see equation (I.36)). Instead, similar trends and conclusions to those derivable from tplot figures can be reached by replacing the BET area as a normalization factor by the amount
adsorbed at some arbitrarily chosen relative pressure, usually P/P0 = 0.4. Therefore, the Alpha-s
method in principle allows a more direct comparison between actual and nonporous reference
isotherms. In practice, complications arise because the Alpha-s method is found to depend on the
exact nature of the material chosen as nonporous reference. Nonetheless, the Alpha-s method (by
analogy with the t-method) has found use for the determination of micropore volumes by
extrapolation of Alpha-s curves to αs = 0, and for the determination of nonporous surface area
contributions (from the slopes of linear portions of Alpha-s curves, since the ratio of actual to
reference BET surface areas is equal to the ratio of actual to reference slopes in these Alpha-s
plot regions), by qualitative comparison of actual isotherms with judiciously selected reference
isotherms.
4.3 MP Method
An extension of de Boer’s t-method for micropore analysis was proposed by Mikhail, Brunauer,
and Bodor 13. . This MP method uses the fact that t can be calculated independently of the solid
by:
t (Å) =
10 4 Vliq
S BET
(I.40)
123 of 158
Autosorb-6iSA/ASWin Operating Manual
I. THEORY AND DISCUSSION
A V vs. t plot is constructed from t vs. P/P0 data for a sample with a similar BET C value, as
shown in Figure I-7 below, using linear slopes constructed for t-value intervals from the origin to
4 Å, 4 to 4.5 Å. 4.5 to 5 Å, etc.
Using the equation above, micropore surface areas can be calculated from the slopes and each
successive interval calculation represents the area of all the micropores remaining unfilled. The
calculations are continued until no further decrease in slope is found in the V vs. t plot,
indicating that all the micropores have been filled. The surface area of pores in the range of
thickness from 4 to 4.5 Å, for example, is the difference between the values calculated from the
first and second slopes. The area of pores in the thickness range from 4.5 to 5 Å is the difference
between the values calculated from the second and third slopes, and so on.
Pore volumes can similarly be calculated, using the relation
V = 10-4 (S 1 - S 2 )  t1 +2 t 2  cm3 g -1
(I.41)
Where
S1 = surface area calculated from slope 1
S2 = surface area calculated from slope 2
t1 = thickness at beginning of interval used for slope 2
t2 = thickness at end of interval used for slope 2
Each succeeding group of pores is correspondingly treated, and a distribution of pore volume is
thus obtained. While the exact pore shape is usually unknown, cylindrical pores are generally
assumed. It has been shown that this pore volume relation is equally valid for cylindrical pores or
parallel plates.
Figure I-7, Typical V vs. t plot with internal slopes
4.4 Dubinin-Radushkevich (DR) Method
Based on the Polanyi potential theory of adsorption[14. ] Dubinin and Radushkevich[15. ]
postulated that the fraction of the adsorption volume V occupied by liquid adsorbate at various
adsorption potentials ε can be expressed as a Gaussian function:
124 of 158
Autosorb-6iSA/ASWin Operating Manual
I. THEORY AND DISCUSSION
  A 2 
 
V = V0 exp − 
  βE 0  
(I.42)
where A is the free energy of adsorption, which in the early Dubinin’s works was called
adsorption potential ε
(I.43)
A = ε = RT ln(P / P )
0
In equation (I.42) V0 represents micropore volume, E0 is the so-called characteristic energy of
adsorption and β is the affinity coefficient which can be approximated[16. ] by a ratio of the
liquid molar volumes v of a given adsorbate and benzene used as the reference liquid:
β=
v
(I.44)
vC 6H 6
Equation (I.42) can be written in the following linear form
2
 RT 
 log10 (P0 / P )2
log10 V = log10 (V0 ) − 2.303
 βE0 
(I.45)
which shows that micropore volume V0 and E0 parameter can be calculated from the linear fit of
the isotherm data plotted as log(V) vs. [log(P0/P)]2. Intercept of the fitted straight line gives
log(V0) while its slope m can be used to calculate E0
E0 =
2.303 RT
m β
(I.46)
The linear range for these plots is usually found at relative pressures of less than 10-2.
Based on empirical studies Dubinin and Stoeckli proposed[17. ] that E0 can be related to the
characteristic micropore width for a carbonaceous adsorbent by the following simple formula
(I.47)
Pore Width = 26 (kJ nm /mol)/E
0
The linear form of the DR equation was also used by Kaganer[18. ] to evaluate micropore
surface area from the plot intercept, log(V0), by applying equation (I.5).
Other modifications[19. ] of the DR method include:
a) Allowing the DR exponent, n, to differ from n=2 in order to provide a better data
fit for non-Gaussian pore size distribution– - see next section;
and
b) Introduction of a supercritical adsorption constant, K, into equation (I.45)



log W = log(W0 ) - m log  K P0 
P 


2
(I.48)
where
W = weight adsorbed at P
W0 = total weight adsorbed
125 of 158
Autosorb-6iSA/ASWin Operating Manual
I. THEORY AND DISCUSSION
m =slope of straight line
K =  PP0c   TTc 
2
Pc = critical pressure of adsorbate (Torr)
P0 = saturated vapor pressure of adsorbate (Torr)
T = adsorption temperature (K)
Tc = critical temperature of adsorbate (K)
Equation (I.48) has been proposed as a valid correlation for adsorption data at temperatures
exceeding the critical temperature of the adsorbate.
4.5 Dubinin-Astakhov (DA) Method
For a large number of microporous materials, the adsorption isotherm can be well characterized
by the Dubinin-Radushkevich equation. However, for those microporous materials with
heterogeneous distributions or strongly activated carbons, the Dubinin-Radushkevich equation
fails to linearize the adsorption data[20. ]. To describe adsorption on wider range of
microporous materials the Dubinin-Astakhov equation was proposed:
  - RT ln P / P0 n 
W = W 0 exp  - 
 
E
 
 
(I.49)
where:
W = weight adsorbed at P/P0 and T
W0 = total weight adsorbed
E = characteristic energy
n = non-integer value (typically between 1 and 3)
is a generalized form of the Dubinin-Radushkevich equation (n=2) and has been found to fit
adsorption data for heterogeneous micropores[21. ].
The Dubinin-Astakhov equation requires the parameters n and E to be calculated re-iteratively
by non-linear curve fitting to the adsorption isotherm in the low relative pressure, micropore
region. The values of n and E obtained are then used in equation (I.50)[22. ].
n
  K n - 3n 
d (w / w0 )
 K  - ( 3n +1 )
exp
= 3n 
 r
 -  r 
dr
E 
  E 

where
r = pore radius
K = interaction constant
(I.50)
= 2.96 kJ x nm3 x mol-1 (N2)
= 2.34 kJ x nm3 x mol-1 (Ar)
A plot of [d(w/w0)]/dr vs. r yields the DA Method pore size distribution (see Figure I-8).
126 of 158
Autosorb-6iSA/ASWin Operating Manual
I. THEORY AND DISCUSSION
Figure I-8, Plot of DA method pore size distribution.
4.6 Horvath-Kawazoe (HK) Method
The HK method[23. ] enables the calculation of pore size distribution of micropores from the
low relative pressure region of the adsorption isotherm. Many pore size distribution methods are
derived from the Kelvin equation, which describes the phenomenon of capillary condensation.
Some have questioned the reliability of the capillary condensation approach in the small confines
of micropores. The HK method is derived independent of the Kelvin equation.
The HK method expresses the adsorption potential function within slit-like micropores as a
function of the effective pore width:




4
10
4
10
 P
N A + N A AA 
σ
σ
σ
σ
 (I.51)
RT ln 
x
+
 = K S 4S
9
3
9
  d 3
σ ( -d )
d
 P0 
d 
d  

9  - 
3  
9   
3   - 
2
2
2 

  2
The parameters As, and AA can be calculated using the following equations:
AS =
6 mc2 α s α A
αs + α A
χs
χA
(I.52)
127 of 158
Autosorb-6iSA/ASWin Operating Manual
AA =
I. THEORY AND DISCUSSION
3 mc 2 α A χ A
2
(I.53)
where,
m = mass of an electron
c = speed of light
α s = polarizability of adsorbent
α A = polarizability of adsorptive
χ s = magnetic susceptibility of adsorbent
χ A = magnetic susceptibility of adsorptive
and
(  - ds) = effective pore width
d = ds + dA
ds = diameter of adsorbent molecule
dA = diameter of adsorbate molecule
 = distance between two layers of adsorbent
σ = 0.858d/2
K = Avogadro’s number
NS = number of atoms per unit area of adsorbent
NA = number of molecules per unit area of monolayer of adsorbate
AA = Kirkwood-Mueller constant of adsorptive
AS = Kirkwood-Mueller constant of adsorbent
By selecting effective pore widths in the micropore range, equation H45 can be used to calculate
the corresponding relative pressures. From the adsorption isotherm, the amount of adsorption at
each of these relative pressures is determined. Differentiation of weight (or volume) of gas
adsorbed relative to the total uptake, W/W0, with respect to the effective pore width yields a pore
size distribution in the micropore range (see Figure I-9, HK method pore size distribution.).
128 of 158
Autosorb-6iSA/ASWin Operating Manual
I. THEORY AND DISCUSSION
Figure I-9, HK method pore size distribution.
4.7 Saito-Foley (SF) Method
Even though the HK method is adequate for materials with a predominance of slit-like pores
(activated carbons, layered clays), certain solids (e.g., zeolites) are better represented assuming
cylindrical pore geometry. Hence, the SF method [24] was developed as an alternative to the slitlike pore-based HK method. As with the HK method, the SF method enables the calculation of
pore size distributions of microporous materials independently from the Kelvin Equation. The
computational approach is analogous to that of the HK method, except that cylindrical pore
geometry is assumed. Accordingly, equation (I.45) is replaced by
RT ln
P
P0
=
( N S AS + N A AA ) x ∞  1  G
3πK
x

Σ
4
( d /2 ) 4
k =0  k + 1 

 d 
G =  1- 

 D 

2k
10
4
  21 
 d  
 d 
 

 ak 
 
bk 
 D  
 D 
  32 
(I.54)
(I.55)
where
 − 1.5 − k 
ak = 

k


2
(I.56)
(I.57)
and
a0 = b0 = 1
129 of 158
Autosorb-6iSA/ASWin Operating Manual
I. THEORY AND DISCUSSION
(D-ds) = effective pore diameter
All of the other parameters have been defined in the previous section (HK method). The
numerical solution of the above equations is again analogous to that of the HK method, and
yields pore size distributions and cumulative pore volumes for cylindrical pores in the micropore
range.
5
Density Functional Theory and Monte Carlo
Simulation Methods
Classical macroscopic, theories like for instance the Dubinin-Radushkevich approach, the BJH
method, and semi-empirical treatments such as those of Horvath and Kawazoe (HK), and Saito
and Foley do not give a realistic description of the filling of micropores and even narrow
mesopores. This leads to an underestimation of pore sizes.
In order to achieve a more realistic description microscopic theories, which describe the sorption
and phase behavior of fluids in narrow pores on a molecular level, are necessary. Treatments
such as the Density Functional Theory (DFT) or methods of molecular simulation (Monte Carlo
simulation (MC) and Molecular Dynamics (MD)) provide a much more accurate approach for
pore size analysis. Hence, methods such as the DFT of inhomogeneous fluids [25, 26] and Monte
Carlo simulations [27, 28] bridge the gap between the molecular level and macroscopic
approaches.
The Non-Local Density Functional Theory (NLDFT) and the Grand Canonical Monte Carlo
simulation (GCMC) methods correctly describe the local fluid structure near curved solid walls;
adsorption isotherms in model pores are determined based on the intermolecular potentials of the
fluid-fluid and solid-fluid interactions. The relation between isotherms determined by these
microscopic approaches and the experimental isotherm on a porous solid can be interpreted in
terms of a Generalized Adsorption Isotherm (GAI) equation:
N (P / P0 ) =
WMAX
∫ N (P / P ,W ) f (W )dW
0
(I.58)
WMIN
where
N(P/P0) = experimental adsorption isotherm data
W = pore width
N(P/P0,W) = isotherm on a single pore of width W
f(W) = pore size distribution function
The GAI equation reflects the assumption that the total isotherm consists of a number of
individual “single pore” isotherms multiplied by their relative distribution, f(W), over a range of
pore sizes. The set of N(P/P0,W) isotherms (kernel) for a given system (adsorbate/adsorbent) can
be obtained, as indicated above, by either Density Functional Theory or by Monte Carlo
computer simulation. The pore size distribution is then derived by solving the GAI equation
numerically via a fast non-negative least square algorithm.
The DFT and the Monte Carlo simulation method have largely been applied to the
characterization of micro- and mesoporous carbons [28-30], silica’s and zeolites [28,31,32].
130 of 158
Autosorb-6iSA/ASWin Operating Manual
I. THEORY AND DISCUSSION
(Please contact support-sp@anton-paar.com for Powder Tech Notes 27, 31 and 36 for more
details).
The ASWin software includes a number of kernels consisting of individual (P/Po, W) isotherms
derived for the systems: nitrogen-carbon, argon-carbon, nitrogen-silica, and argon-silica by the
Non-Local Density Functional Theory and Grand Canonical Monte Carlo computer simulation.
Please refer to a summary in Table I.2 of the kernels implemented in the ASWin software, and
recommendations for the pore width ranges where these models work best.
Library of DFT and GCMC Methods in Quantachrome’s Data Reduction Software:
Table I.2, List of available kernels for DFT and GCMC methods.
NLDFT / GCMC ( Monte Carlo) Kernel File
NLDFT– N2 — carbon equilibrium transition
kernel at 77 K based on a slit-pore model
Applicable Pore
Width Range
0.35 nm – 40 nm
NLDFT– N2 — carbon equilibrium transition
kernel at 77K based on a cylindrical pore model
0.35 nm – 40 nm
NLDFT– N2 — carbon equilibrium transition
kernel at 77 K based on a slit-pore model for
pore widths < 2nm, and a cylindrical model for
pore widths > 2 nm
NLDFT– N2 — silica equilibrium transition
kernel at 77 K based on a cylindrical pore model
0.35 nm – 40 nm
NLDFT– N2 — silica adsorption branch kernel
at 77 K based on a cylindrical pore model for
pores of diameter < 5 nm, and spherical pores
model for pores of diameter > 5 nm
NLDFT– N2 — silica adsorption branch kernel
at 77 K based on a cylindrical pore model
0.35 nm – 100 nm
0.35 nm – 40 nm
0.35 nm – 100 nm
NLDFT– Ar — zeolite/silica equilibrium
transition kernel at 87 K based on a cylindrical
pore model
0.35 nm – 100 nm
NLDFT – Ar — zeolite/silica adsorption branch
kernel at 87 K based on a cylindrical pore model
0.35 nm – 100 nm
Examples
Activated carbons, activated carbon
fibers, novel micro/mesoporous carbons
of type CMK-1 etc.
Novel micro/mesoporous carbons (e.g.
CMK-3, carbon nanotubes, carbon
aerogels) etc.
Novel micro/mesoporous carbons (some
CMK’s), certain activated carbons
Siliceous materials, e.g. some types of
silica gels, porous glasses, MCM-41,
SBA-15, MCM-48 and other adsorbents
which show type H1 sorption hysteresis
Novel siliceous materials with
hierarchically ordered pore structure,
SBA-16 silica, some types of porous
glasses and some types of silica gels.
Siliceous materials such as controlled
pore glasses, MCM-41, SBA-15, MCM48, and others. Allows obtaining an
accurate pore size distribution even in
case of type H2 sorption hysteresis.
Zeolites with cylindrical pore channels
such as ZSM5, Mordenite, and
mesoporous siliceous materials e.g.,
MCM-41, SBA-15, MCM-48, some
porous glasses (e.g. CPG) and silica gels
which show type H1 sorption hysteresis.
Zeolites with cylindrical pore channels
such as ZSM5, Mordenite etc., and
mesoporous siliceous materials such as
MCM-41, SBA-15, MCM-48, porous
glasses and some silica gels etc). Allows
obtaining an accurate pore size
distribution even in case of H2 sorption
hysteresis.
131 of 158
Autosorb-6iSA/ASWin Operating Manual
I. THEORY AND DISCUSSION
NLDFT – Ar — zeolite/silica equilibrium
transition kernel based on a spherical pore
model (pore diameter < 2 nm) and cylindrical
pore model (pore diameter > 2 nm)
NLDFT – Ar — zeolite/silica adsorption branch
kernel at 87 K based on a spherical pore model
(pore diameter < 2 nm) and cylindrical pore
model (pore diameter > 2 nm)
NLDFT – Ar — carbon equilibrium transition
kernel at 87 K based on a cylindrical pore model
0.35 nm – 100 nm
Zeolites with cage-like structures such as
Faujasite, 13X etc.
0.35 nm – 40 nm
Zeolites with cage-like structures such as
Faujasite, 13X etc.
0.35 nm – 7 nm
NLDFT – Ar — carbon equilibrium transition
kernel at 77 K based on a slit-pore model
0.35 nm – 40 nm
NLDFT – Ar — carbon equilibrium transition
kernel at 87 K based on a slit-pore model
0.35 nm – 1.5 nm
NLDFT – CO2 — carbon equilibrium transition
kernel at 273 K based on a slit-pore model
GCMC – CO2 — carbon equilibrium transition
kernel at 273 K based on a slit-pore model
QSDFT – N2 — carbon equilibrium transition
kernel at 77.4 K based on a slit-pore model
0.35 nm – 1.5 nm
Novel micro/mesoporous carbons (e.g.
CMK-3), carbon nanotubes, carbon
aerogels, and others.
Activated carbons, activated carbon
fibers, novel micro/mesoporous carbons
of type CMK-1, and others.
Activated carbons, activated carbon
fibers, novel micro/mesoporous carbons
of type CMK-1, and others.
Ultramicroporous activated carbons,
activated carbon fibers.
Ultramicroporous activated carbons,
activated carbon fibers.
Disordered Micro/Mesoporous carbons
with heterogeneous surface chemistry
(e.g. activated carbons, activated carbon
fibers)
0.35 nm – 40 nm

NOTE! In the case of GCMC – CO2 carbon kernel, a three-center potential
function has been developed[30] with interactions between the sites of different
molecules modeled as a sum of Lennard-Jones and electrostatic contributions.
Hence, the GCMC model may serve as a benchmark for quantitative
estimates[30]. The CO2 – NLDFT kernel is based on a common, one-center,
Lennard-Jones model; this kernel is also important in case a comparison with
appropriate DFT-results in the literature is needed. For details about the
application of CO2 – NLDFT/GCMC kernels please contact applicationsp@anton-paar.com.

NOTE! Contrary to regular NLDFT, the QSDFT method (Quenched Solid
Density Functional Theory), takes into account the effects of surface roughness
and heterogeneity explicitly. Hence, Quantachrome’s library of DFT/GCMC
methods offers the possibility to perform pore size analysis of carbons with
different degrees of surface heterogeneity. This also allows one to assess the
reliability of the pore size analysis of unknown carbon samples. Methods based on
NLDFT are more accurate for ordered carbon materials whereas the QSDFT
method is advantageous for the textural analysis of geometrically and chemically
disordered carbons. For details about QSDFT, contact application-sp@antonpaar.com.
132 of 158
Autosorb-6iSA/ASWin Operating Manual
6
I. THEORY AND DISCUSSION
Thermal Transpiration
At the low pressures commonly employed for nitrogen and argon micropore characterization, the
phenomenon of thermal transpiration [33-35] can result in significant pressure measurement
errors if not compensated.
Thermal transpiration results in a pressure gradient between the sample at temperature, T1 and
pressure, P1 and the pressure transducer at temperature T2 and pressure P2 if the inner diameter of
the tubing between the two parts of the system is very small compared with the mean free path of
the gas. The relationship between pressure and temperature can be expressed as follows for very
low pressures:
P1 = P 2 x
T1 / T2
(I.59)
At higher pressures, the empirical model of Liang34, 35 can be employed to calculate thermal
transpiration corrections for measured pressures.
(I.60)
where
x = 0.133P2d
P1, P2 are in Pascal
d = diameter of connecting tube (m)
Φ is the pressure shift factor that varies for gases relative to the value 1.00 for helium and can be
calculated by
0.27 log φ = log D + 9.59
(I.61)
where D is the molecular diameter of the gas in meters.
133 of 158
Autosorb-6iSA/ASWin Operating Manual
7
I. THEORY AND DISCUSSION
Fractal Dimension Methods
Surface characterization methods based on fractal geometry[36-39] describe the topography of
real surfaces in terms of “ "roughness expone”t" known as fractal dimension, D. Ideal surfaces,
being relatively smooth, can be modeled using simple geometric concepts (e.g., 6L2 for cubes,
4πR2 for spheres, etc.). For such surfaces D=2, because the surface area is proportional to X2,
where X is some characteristic dimension of the adsorbent (e.g., X=L for squares, R for circles,
etc.). In contrast, real surfaces are generally rough because of atom packing arrangements and
defects, kinks and dislocations, and pores themselves, depending on the scale considered.
Many real surfaces present surface irregularities that appear to be similar at different scales.
These surfaces are referred to as fractal because their magnitude is proportional to XD, where D
is a fractional exponent that generally assumes values between D=2 (for smooth surfaces) and
D=3 (for surfaces so rough that they essentially occupy all available volume). The fractal
dimension D can thus be used to quantify the roughness of real surfaces in terms of a single
parameter.
Among the various approaches proposed in the literature to evaluate D, two in particular have
gained popularity because they make use of single gas sorption isotherms for their calculations.
These are the Frenkel-Halsey-Hill (FHH) method[37-39] and the Neimark-Kiselev (NK)
method[37-39].
7.1
Frenkel-Halsey-Hill (FHH) Method
By noting that in the multilayer adsorption region the influence of surface forces tends to be
smoothed out, several independent authors derived an isotherm expression of the general
form[38]
B
log P0 = s
P V
(I.62)
where B is a parameter related to adsorbate-adsorbent and adsorbate-adsorbate interactions, V is
the amount of adsorbed material, and the exponent s is a constant characteristic of a given
adsorbent. Equation (I.62) came to be known as the Frenkel-Halsey-Hill (or FHH) equation.
Pfeifer et al.[37,39] postulated that the FHH exponent s is related to the fractal dimension D of
the adsorbent through the expression
D = 3(1 + s )
(I.63)
In deriving equation (I.63) surface tension effects were neglected. That is, the assumption was
made that the surface tension of the adsorbate at a molecular scale does not differ appreciably
from its bulk liquid value. If surface tension effects are accounted for[39] , the relationship
between D and s is given by:
D = 3+ s
(I.64)
where, D is the surface fractal dimension, and s is a constant characteristic of a given adsorbent.
In either case, for fractal surfaces a plot of log V vs. log[log(P0/P)] should yield a straight line
with negative slope s within the multilayer region of the isotherm.
134 of 158
Autosorb-6iSA/ASWin Operating Manual
I. THEORY AND DISCUSSION
7.2 Neimark-Kiselev (NK) Method
Combining thermodynamic and fractal arguments, Neimark[38] reasoned that above the onset of
capillary condensation fractal surfaces should conform to the following equation:
S lg = K ( ac )
2- D
(I.65)
where, D is the surface fractal dimension, K is a constant, ac is the mean radius of curvature of
the adsorbate-vapor interface, given by the Kelvin equation,
ac = r k =
2 γ Vm
R T ln PP0
( )
(I.66)
and Slg is the adsorbate-vapor interface area, given by the Kiselev equation,
n
Slg =
RT max
γ
 po 
∫ ln p  ⋅ dn
(I.67)
n
with R being the universal gas constant, T the adsorption temperature, γ the adsorbate surface
tension, Vm the adsorbate molar volume, and n and nmax the amounts of gas adsorbed at a given
P/P0 and at saturation, respectively. In other words, the cumulative area Slg was taken to be
equivalent to the adsorbent area measurable with a yardstick of a size proportional to ac at any
given P/P0. Accordingly, a plot of log [Slg] vs. log [ac] should also yield a straight line within the
multilayer region of the isotherm, from which the fractal dimension D can be readily calculated.
135 of 158
Autosorb-6iSA/ASWin Operating Manual
8
I. THEORY AND DISCUSSION
Differential Heat of Adsorption
The differential heat of adsorption ∆Hads is defined as the heat released upon adding a small
increment of adsorbate to the surface of a solid. The value of ∆Hads depends on different factors,
like the strength of the bonds formed upon adsorption, and the degree to which a surface is
covered with adsorbate. Also because of that ∆Hads is often expressed in terms of its variation
with the surface excess/surface coverage.
The differential heat of adsorption can be obtained from a series of adsorption isotherms
measured at different temperatures according to the so-called isosteric method. However, at least
isotherms at two different temperatures T1 and T2 are necessary. Preferably, each isotherm
should be obtained by analyzing a fresh batch of the sample being tested. In analogy to the wellknown Clausius-Clapeyron Equation for a one component gas-liquid system, the following
equation can be applied to determine the differential heat of adsorption ∆Hads[40]:
∆Hads = - RT1T2/(T2-T1)ln(p2/p1)
(I.68)
where R is the universal gas constant, and p2 and p1 are the equilibrium pressures at
temperatures T1 and T2 for a given amount adsorbed na. Hence, a plot of the differential heat of
adsorption as a function of adsorbed amount is based on the overlapping volume range for the
two data files.
136 of 158
Autosorb-6iSA/ASWin Operating Manual
J. APPENDICES
J. APPENDICES
1
System Error Messages
PROBLEM WITH BATH: this error message indicates that the system is not receiving a valid
bath status from the indicated station. This could be caused by an electrical or mechanical
problem with the bath drive on the station, but it is more likely to be caused by a loose or
missing level sensor probe, a Dewar flask that has not been filled with liquid nitrogen or a
missing Dewar flask.
LEAK TEST FAILED: indicates that the station whose number is shown failed the leak test.
The most likely causes of this message are a poorly outgassed sample, a leak around the
cell connection or a leak in the vacuum grease fittings on a two-piece sample cell.
ABORTED LOW LN2: indicates that the station has been aborted because the liquid nitrogen
has dropped below the usable level. If the liquid nitrogen level in the Dewar flask appears
adequate, it may indicate a loose or damaged level sensor probe.
POWER LOSS HAS OCCURRED: indicates that a power outage or loss of vacuum pump
status has occurred, but the system is now back in full operation.
OVER-PRESSURIZATION HAS OCCURRED: indicates that the specified station has been
over-pressurized and all stations have been or are being aborted. If an over-pressurization occurs
during a power loss, the system will respond in the described manner when power is restored but
will be unable to determine the station which caused the over-pressurization.
137 of 158
Autosorb-6iSA/ASWin Operating Manual
2
J. APPENDICES
P/Po Tolerance
Table J.1, Tolerance settings for adsorption and desorption points.
Adsorption P/Po range
0 to 0.1
0.1 to 1
1 to 0.1
0.1 to 0
0
+.00003 -.00001
+.003 -.001
+.001 -.003
+.00001 -.00003
1
+.00006 -.00002
+.006 -.002
+.002 -.006
+.00002 -.00006
2
+.00009 -.00003
+.009 -.003
+.003 -.009
+.00003 -.00009
3
+.00012 -.00004
+.012 -.004
+.004 -.012
+.00004 -.00012
4
+.00015 -.00005
+.015 -.005
+.005 -.015
+.00005 -.00015
5
+.00018 -.00006
+.018 -.006
+.006 -.018
+.00006 -.00018
6
+.00021 -.00007
+.021 -.007
+.007 -.021
+.00007 -.00021
7
+.00024 -.00008
+.024 -.008
+.008 -.024
+.00008 -.00024
8
+.00027 -.00009
+.027 -.009
+.009 -.027
+.00009 -.00027
9
+.00030 -.00010
+.030 -.010
+.010 -.030
+.00010 -.00030
Tolerance
Value

Desorption P/Po range
Tolerance Band Width
(± P/Po)
Tolerance Band Width
(± P/Po)
NOTE! Instruments with the krypton and micropore options will use the low
pressure tolerance values when the cell pressure is below 0.1 atmospheres. The
range automatically switches to the high pressure tolerances when the cell pressure
goes over 0.1.
For micropore analyses (older AS6B Kr/MP model only), the recommended P/P0 tolerance is 0.
The minimum relative pressure and interval that can be specified is 0.00001.
The minimum cell pressure that will be accepted by the instrument is 2 x 10-6 atmospheres.
The minimum relative pressure and interval that can be specified is 0.00001.
The minimum cell pressure that will be accepted by the instrument is 2 x 10-6 atmospheres.
138 of 158
Autosorb-6iSA/ASWin Operating Manual
3
J. APPENDICES
Autosorb Dosing Routine and Equilibration Time
A dose on a sample is performed in the following manner: the pressure in the cell is measured,
the manifold pressure is increased to an amount such that when the cell valve is opened to the
manifold the resulting pressure in the cell will be equal to the desired relative pressure plus the
P/P0 tolerance, assuming that no adsorption occurs. For example, if the desired relative pressure
is 0.100 and a P/P0 tolerance of 0 was selected, the manifold will build to a pressure which, when
opened to the cell, will result in a cell pressure of 0.103 if no adsorption occurs. If the selected
P/P0 tolerance is 9 (see Appendix 2, above), then the system will attempt to achieve a cell
pressure of 0.130. The larger the P/P0 tolerance the larger the dose and consequently the shorter
the analysis time.
When the manifold has reached its target pressure, the cell valve will open for 8 seconds to allow
for gas to transfer and for adsorption from the combined cell and manifold volumes and then the
cell will be isolated for 15 seconds after which the pressure in the smaller volume of just the cell
and station components is measured on the cell transducer. If the cell pressure has dropped below
the target datum point relative pressure the cell is scheduled for another dose, otherwise the cell
is scheduled for an equilibration check in one minute.
During equilibration the pressure in the sample station is measured every six seconds. The
pressure reading is stored in memory and compared against the lower limit of the P/P0 tolerance
(for example with a desired relative pressure of 0.100 and a P/P0 tolerance of 9 the lower limit is
0.09). If the pressure is below the lower limit a dose is scheduled. Otherwise the pressure is
checked for a valid equilibrium condition. A sample is considered to have reached equilibrium
when the pressure changes less than 0.0008 atm. for the period selected by the operator of
between 1 and 99 minutes. For example, if an equilibration time of 2 was specified then each
time the pressure is checked during equilibration the pressure reading is compared to the reading
taken 2 minutes earlier. This will continue until the pressure in the cell drops below the lower
limit of the P/P0 tolerance or the difference between the two readings is less than 0.0008 atm.
The data point is then stored and dosing will begin for the next data point.
If the cell does not meet the equilibrium requirements described above, the target cell pressure
for subsequent doses is increased in order to bring the sample cell to equilibrium sooner.
However, the time it took to drop below the lower tolerance limit is also taken into consideration
so that an overdose does not occur and the sample cannot equilibrate above the upper tolerance
limit.

NOTE! In order to provide the capability of obtaining the lowest possible relative
pressures, a situation may occur in which the pressure requested is equal to
or less than the tolerance band. In this case, the pressure cannot fall out of
the band and the data point will be taken after the first dose, leading to small
volume adsorbed. This can occur only in the micropore region for requested
pressures of about 10-5 which will equilibrate in the cell at pressures in the
10-6 range.
An undesired data point can be edited out of the data reduction calculations (see Section G.6).
139 of 158
Autosorb-6iSA/ASWin Operating Manual
4
J. APPENDICES
Analysis Gas Selection
The Autosorb-6iSA is capable of measuring the adsorption of any non-corrosive gas. In order to
obtain meaningful data, several parameters must be known about the adsorbate.
Prior to reducing the void volume (Vv) to standard conditions, the measured volume is corrected
for nonideality. Using V ꞌv as the corrected void volume, the correction for nonideality is:
V ′v = V v ( 1 + αP )
(J.1)
Table J.2, Physical parameters for common adsorptive gases includes the alpha value for several
gases at various temperatures.

NOTE! When entering the alpha correction factor do not enter the exponent. The
computer will multiply the entered value by 10-5.
Table J.2, Physical parameters for common adsorptive gases also includes the cross-sectional
areas and molecular weights of several gases.
The coolant used should provide a saturated vapor pressure, P0, of 10 mm or greater. If it is
necessary to use an adsorbate and coolant with a lower P0 the user should enter the saturated
vapor pressure during initialization of the run.
!
CAUTION! When changing adsorbates be sure to evacuate the adsorbate lines in
the Autosorb (manual mode) and then purge them with the new gas.
140 of 158
Autosorb-6iSA/ASWin Operating Manual
J. APPENDICES
Table J.2, Physical parameters for common adsorptive gases (Adsorbates)
Molecular
Weight
(g/mol)
Gas
N2
28.0134
Ar
39.948
CO2
44.01
C4H10
58.12
Kr
83.80
Cross
Sectional
Area
2
(Å /molecule)
Approx*
Temp.
(K)
Approx
Temp.
(°C)
Approx Po
(Torr)
α Factor
x 10-5
(Torr-1)
77
-196
Atm + 10
6.58
87
-186
2130
3.78
77
-196
203
11.4
13.85
1.450
87
-186
Atm + 10
3.94
14.2
1.400
195
-78
Atm
2.75
248
-25
12600
1.55
273
0
26140
0.91
0.927
273
0
774
14.2
0.601
298
25
1770
4.21
77
-196
2.63
3.00
87
-186
13
3.00
16.2
Liquid
Density
(g/cc)
0.806
0.759
1.562
21
46.9
20.5
1.054
0.574
2.413
2.600
*For general guidance only; these values may or may not agree with the values in adsorbate
and/or data reduction parameters.
•
•
•
•
77 = liquid nitrogen
87 = liquid argon
195 = dry ice / acetone
273 = ice / water
141 of 158
Autosorb-6iSA/ASWin Operating Manual
5
J. APPENDICES
Krypton Operations (legacy Autosorb-6B only)
Earlier Autosorb-6B units could have been supplied with the krypton option. At the measurement
temperature of ~77K, krypton is below its triple point temperature and it sublimates. Its
saturation pressure over solid is about 1.6 torr. However, for the application of the BET method
the saturation pressure of supercooled liquid krypton is usually adopted. The saturation pressure
of the supercooled liquid krypton at ~77K is 2.63 torr which is about 300 times lower than P0 of
liquid N2. It follows that when Kr is used in the BET analysis, the absolute gas pressure in the
sample cell is much smaller than in the case when N2 is used. This makes the corrections for void
volume much smaller and measurement sensitivity much higher for the analysis with Kr
compared to the standard N2 analysis.
For low surface area samples, the sample cell with large bulb is recommended to accommodate
large amount of sample.
The saturated equilibrium vapor pressure, P0, for krypton is usually taken as 2.63 mm Hg at the
temperature of liquid nitrogen at standard pressure. This value corresponds to the vapor pressure
of the supercooled liquid state of krypton. You can obtain the equilibrium vapor pressure of
supercooled liquid krypton in any of the following ways during initialization:
It may be manually entered from the keyboard. Enter 2.63 mm Hg as User Entered P0.
You can instruct the Autosorb-6B to solidify krypton in the P0 cell and measure the equilibrium
vapor pressure of solid krypton if this value is deemed appropriate. Normally P0 corresponding
to supercooled liquid krypton is used.
You can remove the P0 cell from its station and allow the Autosorb-6B to measure ambient
pressure from which the equations below will be used to calculate the liquid P0.
You may keyboard enter ambient pressure in mm of Hg and the system will calculate the
equilibrium vapor pressure of supercooled liquid krypton from the equations given below.
The equation referred to above, the Clausius-Clapeyron Equation, is:
1
 P  ∆H v  1
ln a  =
− 

R  77.4 T 
 760 
(J.2)
Where, ∆ H v is the heat of vaporization of liquid nitrogen and P a represents the local
barometric pressure in mm of mercury.
This equation is used to calculate the bath temperature from ambient pressure assuming the heat
of vaporization of liquid nitrogen is 1330 cal mol-1 .
From the calculated bath temperature the saturated equilibrium vapor pressure of supercooled
liquid krypton is calculated from:
log P0 = - 899.979 ( 1/T ) - 12.55400(logT ) + 34.38392 + 0.0175105 T
(J.3)
142 of 158
Autosorb-6iSA/ASWin Operating Manual
6
J. APPENDICES
Sample Cells
Sample cell choice is important when performing physisorption measurements. Anton Paar
QuantaTec offers a variety of sample cells for the Autosorb-6iSA. The Autosorb-6iSA Glassware
Reference Table is presented at the end of this section.
6.1 Standard Physisorption Cells
Pellet Cell, Small : used for small quantities of pellet samples or powders of surface area
>10m2/g
Pellet Cell, Large : used for pellet or powder samples when larger quantities are required for an
analysis of surface area surface area <10m2/g, and for more rapid analysis of high surface
area/large pore volume samples.
The small and large pellet cells are supplied with stem diameters of 6, 9, and 12 mm and in
borosilicate (Pyrex™) or quartz (when high degassing temperatures >350°C are required, quartz
glassware is indicated by a “-1” suffix in the part number). The appropriate adaptor sleeve, insert
(filler rod), and O-ring must be used with each cell.
Bulkhead cell
adaptor accepts
6, 9, and 12mm
stem sizes.
Adaptor Sleeves
193362, 193363,
& 193364
Filler Rods
193623,
193870,
193873
Small pellet cells
193621, 193846,
193632 & 193863
Large bulb cells
193622, 193849,
193633, 193864,
193635, 193866
Figure J-1, Standard physisorption cells and adaptor sleeves.
143 of 158
Autosorb-6iSA/ASWin Operating Manual
J. APPENDICES
6.2 Two-piece Sample Cells
If the sample is difficult to load into a standard sample cell (because it sticks to the wall of the
stem for example) a two piece cell might be appropriate. Special vacuum grease must be used to
seal the joint between the two pieces as (i) it will see degassing temperature (max 200°C) and (ii)
cryogenic temperatures; Order P/N 214254.
Powder Cell : (P/N 193620) used for fine powders, which are placed in the bulb of the cell and
connected to a 1 mm cell stem (P/N 193618). The sample bulb is 10 x 28 mm.
T-Cell Body : (P/N 193617) used for larger quantities of powder or pellets of low surface area
materials. A 1 mm cell stem (P/N 193618) is used with the T-cell (10 x 50 mm).
1 mm ID cell stem P/N 193618
Figure J-2, Two-piece cell assembies.
T-Cell Body P/N 193617
Powder Cell
P/N 193620
Micro Powder Cell : (P/N 193626) used for fine powders to minimize the void volume; bulb
volume is about 0.8cc.
Figure J-3, Micro powder cell assembly.
Macro Cell : Macro Cell cap (P/N 193624) used for large solid pieces of sample. A 1 mm-cell
stem (P/N 193625) is used with cap. The cell dimensions are 18 x 40 mm. This cell requires a
wide mouth Dewar, P/N 193646.
Macro Cell Cap
P/N 193624
Macro Cell Stem
P/N 193625
Figure J-4, Macro cell assembly.
144 of 158
Autosorb-6iSA/ASWin Operating Manual
J. APPENDICES
6.3 Valved Sample Cells
Those samples that are highly sensitive to exposure to ambient air can be transfeered from the
degasser or glove box using valves cells. Regular vacuum grease (should be used to both
luibriucate the stopcock and to seal the two parts of the cell after the sample has been
introduced).
Large Stopcock Cell: (P/N 193630, 193859, and 193860) overall dimensions similar to standard
physisorption cell with a large (approximately 1”, 2.5cm) diameter bulb.
Small Stopcock Cell: (P/N 193631, 193861) overall dimensions similar to standard
physisorption cell with a large (approximately 1”, 2.5cm) diameter bulb.
Figure J-5, Valved cell assemblies: “Small” (left) and “Large” (right).
6.4 Saturation Pressure Cell
Po Cell: (P/N 193627) used to measure the saturated vapor pressure of adsorbate during an
analysis. It is easily distinguishable from a sample cell by its 90° bend!
Sample must never be placed in this cell.
145 of 158
Autosorb-6iSA/ASWin Operating Manual
J. APPENDICES
Table J.3, Autosorb-6iSA Glassware Reference Table
Part
Number
193628
193622
193849
193621
193846
193633
193864
193632
193862
193635
193866
193623
193870
193873
193871
193630
193859
193860
193631
193861
193648
193649
217946
193617
193618
193619
193620
193626
193627
Description
Physisorption Cells
Cold Trap Tube Front
6mm Large Cell
6mm Large Cell, Quartz
6mm Sm. Pellet Cell
6mm Sm. Pellet Cell, Quartz
9mm Large Cell, Dimpled
9mm Large Cell, Quartz
9mm Sm. bulbless
9mm Sm. bulbless, Quartz
12mm Large Cell, Dimpled
12mm Large Cell, Quartz
Filler Rod for 6mm Cell
Filler Rod for 9mm Cell
Filler rod, 12mm Cell
Filler Rod for 6mm Quartz Cell
Filler Rod for 9mm Quartz Cell
Filler rod, 12mm Quartz Cell
Specialty Cells
6mm Large Stopcock Cell
9mm Large Stopcock Cell
9mm Large Stopcock Cell, Quartz
6mm Small Stopcock Cell
9mm Small Stopcock Cell
9mm Small Stopcock Cell, Quartz
Macro Cell Cap
Macro Cell
Small Base Pellet Cell (2pc)
Small Base Pellet Cell Quartz
Large Base Bulb Cell (2pc)
Small Base Bulb Cell Quartz
6mm Quartz Bulbless 0.34cc Cell
T Cell Body, 4mm ID
6mm Stem 1mm capillary
6mm Stem 4mm ID
Powder Cell Body, 4mm ID
Micro Powder Cell Assembly
Saturation Pressure Cell
Autosorb Po Cell
Companion
Parts
N/A
193623
193623
193870
193871
193870
193871
193873
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
193649
193648
N/A
N/A
N/A
N/A
N/A
193618, 193619
N/A
193867
193618, 193619
N/A
N/A
146 of 158
Autosorb-6iSA/ASWin Operating Manual
7
J. APPENDICES
Maintenance Addendum
Recommended Maintenance Required for Warranty Validation
7.1 Maintenance performed by an authorized Anton Paar Service
Engineer
The Autosorb6iSA requires periodic maintenance which must be performed by an authorized
Anton Paar Service Engineer*. Failure to perform the minimum level of maintenance may result
in voiding the warranty†.
Maintenance Interval:
• Once every 12 months (Annually)
Required parts exchanged as part of the routine annual maintenance:
• Bulkhead Filters
• Bulkhead O-Rings
• Station O-Rings
• Vacuum Pump Oil
• Vacuum Gauge Tube
Parts to be exchanged at extended service intervals:
• All Valve repair kits to be replaced every 60 months
• Valve fitting O-rings to be replaced every 60 months
• Valves to be replaced every 60 months
7.2 Upkeep and Cleaning
In order to maintain the most accurate and highest level of performance, it is critical that routine
housekeeping be performed on your Autosorb 6iSA.
Table 3: User-recommended Upkeep
Housekeeping Activity
Frequency
Brush stray material from the top of instrument and on face of instrument
Weekly or as needed
Replace Foreline trap material
Every 6 months
Clean dewars
Every month
Replace Station O-rings
Every 3 months or as needed
Pump Oil replacement
Every 6 months or as needed
* Please contact your local Anton Paar representative to discuss maintenance options. You can find your
representative's contact data on the Anton Paar website under Contact.
† For detailed information, please see the general terms of delivery (GTD) on the Anton Paar website.
147 of 158
Autosorb-6iSA/ASWin Operating Manual
J. APPENDICES
7.3 In Case a Repair is Required
In case your instrument needs repair, contact your local Anton Paar representative, who will take
care of the necessary steps. If your instrument needs to be returned, request an RMA (Return
Material Authorization Number). It must not be sent without the RMA and the filled “Safety
Declaration for Instrument Repairs.” Please make sure it is decontaminated before return, and all
stations are plugged with a dowel pin.
K. Vacuum Pump Maintenance
Follow the maintenance instructions per the vacuum pump manufacturer. It is recommended that
the vacuum pump oil be changed every six months. The following table provides the part
numbers for any needed pump accessories.
Table J.4, Vacuum Pump Accessories
Vacuum Pump Item
Part Number
Flange Stub
196434
Centering Ring Assembly
196435
Aluminum Clamp
196436
Vacuum Tubing
199378
P3 Vacuum Pump Oil
193678
Alumina for Foreline Trap
193934
1.1 Checking / Adjusting Flow Rates Input Pressure
When the gas tanks or regulators are changed, the following procedure should be used to set the
flow rates. Note 1 Torr = 1 mmHg.
For all gases, the input pressure should be between 8-10 psig, except hydrogen (4-6 psig).
!
CAUTION. If you are unsure as to exactly how to proceed, STOP and contact
support-sp@anton-paar.com for advice.
1. To test input pressure, first adjust the regulator(s) well below 10 psig.
2. Enter Manual Mode from the OPERATIONS menu. Read the warning. Click Yes if you want
to continue. Refer to Fig J.8 (below).
3. Click Close all valves then open the coarse adsorbate valve. Observe the manifold pressure on
the front panel meter. If it rises above 1200 Torr, close the coarse adsorbate valve, then open and
close the fine vacuum valve until the pressure stays below 1000 Torr. Make sure both vacuum
valves are closed before proceeding.
148 of 158
Autosorb-6iSA/ASWin Operating Manual
J. APPENDICES
4. Increase the regulator setting, until the pressure on the front of the instrument is about 1225 to
1275 Torr. Note that 1277 Torr is 10 psig, 1225 is 9 psig, 1177 Torr is 8 psig, 1018 Torr is 5
psig. Observe the pressure on the regulator, note any offset between 10 psig and the reading.
Warning: Never adjust the pressure above 1300 Torr in this mode.
5. Repeat for helium using its dedicated valve on the manual mode screen.
Coarse adsorbate valve
Fine adsorbate valve
Fig J.8, Manual mode screen
If unusually long times are needed to achieve a desired relative pressure, it may be necessary to
adjust the flow rates. Follow the procedure below to determine if the flow rates are within the
proper range and adjust if necessary.
!
CAUTION. If you are unsure as to exactly how to proceed, STOP and contact
support-sp@anton-paar.com for advice.
1
Enter Manual Mode from the OPERATION menu.
2
Read the warning message. Click Yes if you want to continue.
3
The screen will then show the manual mode.
4
Click Close all valves, then open the coarse vacuum valv– - leave it open until the the
pressure shown in the Manifold is less than 1 Torr (mmHg), then close it.
5
Now open the gas valve for the flow that is to be adjusted (helium, fine adsorbate or coarse
adsorbate).
149 of 158
Autosorb-6iSA/ASWin Operating Manual
J. APPENDICES
6
Note the change in the manifold pressure displayed on the front panel digital meter each time
the reading is updated. Note, it updates faster than the screen in the software!
7
Close the coarse vacuum valve before the pressure exceeds 700 Torr (mmHg).
8
Each update on the front panel meter should show a change of manifold pressure readings of
30 to 40 Torr (mmHg) for helium, 1 Torr (mmHg) for fine nitrogen and 10 to 15 Torr
(mmHg) for coarse nitrogen.
9
If it is necessary to make an adjustment you will need to locate the needle valves which
control gas flow rates; they are located in the manifold compartment at the top of the
instrument which is accessed by removing the top panel (secured by a number of screws).
They can be found adjacent to the relevant blue-bodied valves (HE = helium, CN2 = coarse
adsorbate, FN2 = fine adsorbate).
10 Repeat the process of evacuating the manifold, closing the vacuum valve, opening the
required gas valve, noting the change in the manifold pressure, then opening the system valve
and adjusting the needle valve.
11 When the correct flow is set, close the gas valve and repeat for the next gas valve.
150 of 158
Autosorb-6iSA/ASWin Operating Manual
2
J. APPENDICES
Repair
CAUTION. Only personnel trained for this purpose shall service this instrument.
There are no user-serviceable parts except those explained in section 7
above.
!
If you need repair of your Quantachrome Autosorb-6iSA, or have a problem with an analysis that
does not seem to be simply application related, please contact our Service Department here in the
United States or your local authorized Quantachrome representative:
In North America contact:
Quantachrome Instruments
1900 Corporate Drive, Boynton Beach, FL 33426
Tel: 1-800-989-2476 (between 8:30 AM and 5:00 PM Eastern Time)
Fax: (561) 732 9888
Email: support-sp@anton-paar.com
Outside of North America contact your local, authorized Quantachrome representative.

NOTE! Do NOT return a unit for service or repair without prior authorization.
When you first contact Quantachrome or a representative, please provide or have the following
information readily available:
•
instrument model and number serial number (to be found on the plate affixed to the rear of
the unit: See Section 11 below for information regarding the serial number plate.
•
a detailed description of the problem,
•
the recent history of the unit (was the unit relocated for example)
•
ASWin software version (see Help>About box on main menu) and Windows operating
system.
151 of 158
Autosorb-6iSA/ASWin Operating Manual
3
J. APPENDICES
Troubleshooting Guide
Many problems with the quality of data (results) are associated with the use of plastic gas input
lines which should never be used. Also, many results-related problems are caused by impure gas
– check for leaks at all connection points between the gas cylinder and the back of the
instrument. Be sure to flush the gas input line properly after changing gas cylinders.
Symptom
Open isotherm (adsorption/
desorption loop does not
close), i.e. desorption branch
always lies above adsorption
branch even at low relative
pressure.
Table J.6, Troubleshooting Guide
Reason
Under-equilibrated
conditions.
Incomplete degassing.
Leaks.
Crossed isotherm.
Incomplete isotherm.
System contamination.
Ran out of LN2 because
the dewar was not filled
sufficiently at the start.
Too much sample.
Overly long
equilibration times in
combination with very
many points.
Dewar failing.
Power failure.
Valve lights not lit.
Power off.
Over-pressure in cell(s).
Unexpectedly high surface
area value.
Weighing error.
Unexpectedly low surface
area value.
Sample not /
insufficiently outgassed.
Action
If isotherm is unexpectedly open,
extend the desorption equilibration
time. Microporous materials often
need longer desorption
equilibration times.
Extend degassing time and/or
increase out gassing temperature.
Check integrity of O-ring on
sample cell. Make sure O-ring is
lightly greased. Make sure that the
bulkhead is free from other Orings.
Pump down unit overnight.
Repeat analysis with filled dewar.
Rerun with less sample.
Reduce equilibration time to 3,
reduce number of points e.g. <100.
Replace dewar.
Use UPS to maintain unit
operational during short power
interruptions.
Check mains power supply and
switch at rear of unit.
Carefully remove cell and/or dowel
pin from one or more stations.
Double check empty cell tare
weight & sample mass/not
backfilled with helium.
Re-outgas sample & rerun.
152 of 158
Autosorb-6iSA/ASWin Operating Manual
Instrument appears inactive
during analyses (fine and/or
coarse ADS valve open).
Instrument appears inactive
during analyses (fine and
coarse ADS valves closed).
J. APPENDICES
Weighing error.
Double check empty cell tare
weight & sample mass, make sure
post-degassed weight is used – not
pre-outgassed weight.
Insufficient gas
pressure.
Check gas supply (isolation valves,
regulator setting, replace cylinder).
Normal operation during Check instrument messages – F8 or
equilibration periods.
CTRL B – for background activity.
Powder up cell stem.
Elutriation.
“Bath Error” before any
points acquired.
Failure to sense coolant
level.
No coolant.
Use Fine Evacuation setting (Start
Analysis parameter).
Use wider stem cell and/or large
bulb cell and/or less sample
volume. Refer to Powder TechNote
#32 (please email supportsp@anton-paar.com).
Install or replace correct coolant
level sensor.
Fill Dewar.
If problems persist, contact your local Quantachrome representative or Quantachrome’s service
department by email service-sp@anton-paar.com or call 1-800-989-2476. Please provide the
following information: instrument serial number (on serial number plate at rear of unit),
firmware version (can be seen in boot-up screen after power-up), software version (“About”
box), log file(s) for period(s) when problem(s) occurred, a description of valve status at time of
problem, and affected data files.
153 of 158
Autosorb-6iSA/ASWin Operating Manual
4
J. APPENDICES
Storage and Transport
It is recommended that the Autosorb-6iSA be left ON at all times if it is to be used on a regular
basis. However, if the instrument will not be used for some time, the following procedures
should be used to idel it or shut it down.
!
CAUTION! Do not purposefully shut off power to the Autosorb-6iSA while an
analysis is in progress.
4.1 Overnight
When not in use for more than a few hours:
1
Remove and empty the dewar flasks.
2
Remove sample cells and plug each analysis port with a stainless steel dowel.
4.2 Short-term shut down
When not in use for a few days, proceed as above, then:
3
Remove Po cells and install stainless steel dowels in all Po stations.
4
Turn off both MAINS and ELECTRONICS breakers at at the rear of the instrument.
5
Make sure the vacuum pump is off; disconnect the machine from the mains power supply.
6
Close the gas supplies at the regulators.
4.3 Long-term shut down
Follow steps 10.Error! Reference source not found. and 10.Error! Reference source not
found. above and in addition:
7
Remove the coolant level sensors and store carefully.
8
Disconnect the gas input lines from the instrument.
9
Disconnect the vacuum hose from the vacuum pump; cap the hose and pump.
If the unit is not going to be used for a considerable amount of time it should still be protected
from possible damage and water splash. The original packaging material is suitable as protection
for long term storage. The machine should always be stored and transported the “right way up”,
i.e. the same orientation in which it is used.
154 of 158
Autosorb-6iSA/ASWin Operating Manual
5
J. APPENDICES
ASWin Software Installation Instructions for Windows®
Vista Users
This Appendix describes the steps and options available during installation/re-installation of the
ASWin software.
5.1 General Notes
The installer properly identifies whether this is a possible update or a first installation (by
maintaining values in the system registry). Also, the root data folder (by default set to
C:\QCdata) is maintained, and cannot be changed upon subsequent upgrade-like installations. If
the root of the data folder needs to be moved, the software need be un-installed using the host
operating system's facility, and a full first installation be performed.
The installation needs be performed by an Administrator level user (as common data is stored in
the registry). This data is NOT modified during operation of the software, so the application need
not run by Administrator privileges. However, the users running the installed software MUST
have the following rights to the Data Root folder, all sub-folders and files within:
• Read
• Create
• Modify
Delete right is NOT required.
The user must also have Read rights to the Registry's HKEY_LOCAL_MACHINE Hive
(specifically the Key, SubKeys and Values under \Software\Quantachrome Instruments).
Please consult your operating system's documentation or your system administrator on how to
manage access rights.
5.2 Remarks
CFR:
This feature is only available while installing the 21 CFR-Part 11
compliant version of the software.
BDE:
The Borland Database Engine is a shared library developed by Borland
International, and is distributed under the appropriate licensing terms.
The version included with our software products is version 5.1.0.4, the
latest as of this writing, and presumably the last one (as BI stopped
developing this component).
Users using other products relying on the BDE should ensure that this
version is compatible with those applications. The BDE will NOT be uninstalled without software, as the licensing terms require us to use
Borland's own installer, and that does NOT provide uninstall feature. Also,
once the BDE is upgraded, there is no “down-grade” option.
155 of 158
Autosorb-6iSA/ASWin Operating Manual
REFERENCES
REFERENCES
1.
S. Brunauer, P. Emmett and E. Teller, J. Amer. Chem. Soc., 60, (1938) 309 .
2.
A. V. Kiselev and Y. A. Eltekov , World Congress on Surface Activity, Vol. II, p. 228,
Butterworths, London, 1957.
3.
S. Lowell, J. Shields, G. Charalambous and J. Manzione, J. Colloid Interface Sci., 86
(1982) 191.
4.
S. Brunauer, L.S. Deming, W.S. Deming and E. Teller, J. Amer. Chem. Soc., 62
(1940) 1723.
5.
J.H. de Boer, “The Structure and Properties of Porous Materials,” p. 68, Butterworths,
London, (1958).
6.
J.H. de Boer, B.C. Lippens, B.G. Lippens, J.C.P. Broekhoff, A. van den Heuvel and
Th. V. Osinga, J. Colloid Interface Sci., 21 (1966) 405.
7.
E.P. Barrett, L.G. Joyner and P.P. Halenda, J. Amer. Chem. Soc., 73, 373 (1951).
8.
D.Dollimore and G.R. Heal, J. Appl. Chem. 14, (1964) 109.
9.
G.D. Halsey, J. Chem. Phys., 16 (1948) 931.
10. J.H. de Boer, B.G. Linsen, Th. van der Plas and G.J. Zondervan, J. Catalysis, 4 (1965)
649.
11. R.W. Magee, Evaluation of the External Surface Area of Carbon Black by Nitrogen
Adsorption, Presented at the meeting of the Rubber Division of the American Chem.
Soc., October, 1994.
12. K.S.W. Sing, Surface Area Determination, D.H. Everett and R.H. Ottewill, Eds.,
Butterworths, London (1970), p.25,
13. R.S. Mikhail, S. Brunauer and E.E. Bodor, J. Colloid Interface Sci., 26 (1968) 45.
14. M. Polanyi, Verh. Dtsch. Phys. Ges., 16, (1914) 1012.
15. M.M. Dubinin and L.V. Radushkevich, Dokl. Akad. Nauk. SSSR, 55, (1947) 331.
16. M.M. Dubinin, Chemistry and Physics of Carbon, Vol 2, pp. 51-118. P. L. Walker
(Ed.), Marcel Dekker, New York, 1966.
17. M.M. Dubinin and H.F. Stoeckli, J. Colloid Interface Sci., 75 (1980) 34.
18. M.G. Kaganer, Zh. Fiz. Khim., 32, (1959) 2209.
19. M.M. Dubinin, Chem. Rev. 60, (1960) 235.
20. H. Marsh and B. Rand, J. Colloid Interface Sci., 33, (1970) 101.
21. H.F. Stoeckli, Carbon, 28, No. 1(1990) 1-6.
22. M.J.G. Janssen and C.W.M. van Oorschot, The Characterization of Zeolites by Gas
Adsorption, in Zeolites: Facts, Figures, Future, 1989, P.A. Jacobs and R.A. van Santen
(Eds.) Elsevier.
23. G. Horvath and K Kawazoe, J. Chem. Eng. Japan, 16, No. 5 (1983) 470-475.
156 of 158
Autosorb-6iSA/ASWin Operating Manual
REFERENCES
24. A. Saito and H.C. Foley, AIChE Journal, 37 (1991) 429.
25. R. Evans, U.M.B. Marconi and P. Tarzona, J. Chem. Soc. Faraday Trans. II, 82 (1986)
1763.
26. P.I. Ravikovitch, G.L. Haller, A.V. Neimark, Advances in Colloid and Interface
Science, 76-77 (1998) 203.
27. K.E. Gubbins, In Physical Adsorption: Experiment, Theory and Application,
J.Fraissard (ED.), Kluwer: Dordrecht, 1997.
28. L.D. Gelb, K.E. Gubbins, R. Radhakrsihnan, and M. Sliwinska-Bartowiak, Rep. Prog.
Phys. 62 (1999) 1573.
29. N.A Seaton, J.P.R.B. Walton and N. Quirke, Carbon 27 (1989) 853.
30. A. Vishnyakov, P. Ravikovitch, and A.V. Neimark, Langmuir 16 (2000) 2311.
31. A.V. Neimark, P.I. Ravikovitch, M. Gruen, F. Schueth, and K.K. Unger, J. Colloid
Interface Sci, 207 (1998) 159.
32. P.I. Ravikovitch, D. Wie, W.T. Church, G.L. Haller, and A.V. Neimark, H. Phys.
Chem. B 101 (1997) 3671.
33. S. Dushman, Scientific Foundations of Vacuum Technique, p. 65, J. Wiley & Sons,
New York (1989).
34. S.C. Liang, J. Phys. Chem., 57 (1953) 910.
35. K.F. Poulter et al., Vacuum, 33, No. 6 (1983) 311-316.
36. D. Avnir (Ed.), The Fractal Approach to Heterogeneous Chemistry, J. Wiley & Sons,
New York, (1989).
37. P. Pfeifer, Y.J. Wu, M.W. Cole and J. Krim, Phys. Rev. Lett. 62 (1989) 1997.
38. A.V. Neimark, Ads. Sci. Tech., 7 (1991) 210.
39. P. Pfiefer, J. Kennter, and M.W. Cole, Fundamentals of Adsorption (Edited by A.B.
Mersmann and S.E. Sholl), Engineering Foundation, New York, p. 689 (1991).
40. Rouquerol, J. Rouquerol & K. Sing, Adsorption by Powders & Pourous Solids,
Academic Press: 1999.
41. S. Lowell, J.E. Shields, M.A. Thomas and M. Thommes, Characterization of Porous
Solids and Powders: Surface Area, Pore Size, and Density, Springer: 2004.
42. K.S.W. Sing, D.H. Everett, R.A.W. Haul, L. Moscou, R.A. Pierotti, J. Roquerol, and T.
Siemieniewska, Pure Appl. Chem. 57 (1985) 603.
43. T.L. Hill, J. Phys. Chem. 59 (1955) 1065.
44. I. Langmuir, J. Am. Chem. Soc., 38 (1916) 2221.
45. I. Langmuir, J. Am. Chem. Soc., 39 (1917) 1848.
46. I. Langmuir, J. Am. Chem. Soc., 40 (1918) 1361.
47. H. E. Kissinger, J. Res. Natl. Bur. Stand., 57 (1956) 217.
48. H. E. Kissinger, Anal. Chem., 29 (1957) 1702.
157 of 158
Autosorb-6iSA/ASWin Operating Manual
REFERENCES
49. P.A. Redhead, Vacuum, 12 (1962) 203.
50. A.W. Coats and J.P. Redfern, Nature, 201 (1964) 68.
51. M. Thommes, et al, “Aspects of a novel method for the pore size analysis of thin silica
films based on krypton adsorption at liquid argon temperature (87.3 K),” Studies in
Surface Science and Catalysis, 165 (2007) 551.
52. Rouquerol, J., Llewellyn, P. and Rouquerol, F. "Is the BET equation applicable to
microporous adsorbents?" In: Characterization of Porous Solids VII. P. Lewellyn, F.
Rodriguez-Reinoso, J. Rouquerol, N. Seaton (Eds): Studies in Surface Science and
Catalysis, 160 (2007) 49-56.
158 of 158