SUPPLEMENTAL OXYGEN
MANUAL FOR MODELS
100, 200, 300 ANALYZERS
California Analytical
Instruments, Inc.
1312 West Grove Avenue, Orange, CA 92865 - 714 974-5560 - Fax 714 921-2531
Website: www.gasanalyzers.com
Section 1
Model 100/200/300 Supplement
Preface
This instruction manual is supplemental to the Model 100/200/300 Operations and Maintenance
Manual for infrared analyzers. It is sent whenever oxygen is one of the measured parameters of
the analyzer.
The oxygen measurement information is divided into two parts:
ƒ
Part 1 – Oxygen by chemical fuel cell sensor techniques.
ƒ
Part 2 – Oxygen by paramagnetic oxygen sensor techniques.
Please refer to the appropriate part of this supplemental manual according to the
method of oxygen determination for your particular analyzer.
Thank you.
Supplemental Manual Oxygen- V7.1.doc
1-2
Section 1
Model 100/200/300 Supplement
Table of Contents
Part 1 – Oxygen by Chemical Fuel Sensor Techniques ...................................................................5
1. FUEL CELL DETECTOR OPTION ............................................................................................6
1.1. Description Fuel Cell Detector Option ................................................................................6
1.2. Product Specifications (Galvanic Fuel Cell Detector).........................................................6
1.3. Principle of operation..........................................................................................................7
1.4. Oxygen Fuel Cells ..............................................................................................................7
2. Preparations for Operation ........................................................................................................8
2.1. Power On............................................................................................................................8
2.2. Zero Adjustment .................................................................................................................8
2.3. Span Adjustment ................................................................................................................8
2.4. Start-Up & Routine Maintenance........................................................................................8
2.5. Zero and Span Calibration Frequency................................................................................8
3. ADJUSTMENTS CHECKS AND REPAIRS...............................................................................9
3.1. Electrical Zero Adjustments................................................................................................9
3.2. Electrical Span Adjustments...............................................................................................9
3.3. The Oxygen Sensor..........................................................................................................10
3.3.1. Coarse-Span-Adjustment ..........................................................................................10
3.3.2. Sensor Checks ..........................................................................................................10
3.3.3. Sensor Replacement.................................................................................................10
4. Chemical Fuel Cell Sample Flow (Supplemental) ...................................................................11
5. Electrical Drawings ..................................................................................................................12
Part 2 – Oxygen by Paramagnetic Oxygen Sensor Techniques.....................................................16
6. PARAMAGNETIC OXYGEN OPTION.....................................................................................17
6.1. Description........................................................................................................................17
6.2. Product Specifications Paramagnetic Oxygen Detector...................................................17
6.3. Principle of operation........................................................................................................18
7. Preparations for Operation ......................................................................................................20
7.1. Power On..........................................................................................................................20
7.2. Zero Adjustment ...............................................................................................................20
7.3. Span Adjustment ..............................................................................................................20
7.4. Zero and Span Calibration Frequency..............................................................................20
8. Start-Up & Routine Operation..................................................................................................21
8.1. Sampling System..............................................................................................................21
8.2. Cross sensitivity of gases .................................................................................................22
8.2.1. Example 1 .................................................................................................................22
8.2.2. Example 2 .................................................................................................................22
9. Mechanical Zero Adjustment (Not required with some sensor models) ..................................24
Supplemental Manual Oxygen- V7.1.doc
1-3
Section 1
Model 100/200/300 Supplement
Table of Figures
Figure 2-1 AC Power Switch, Connector, and Fuse .........................................................................8
Figure 4-1 Chemical fuel cell sample flow ......................................................................................11
Figure 5-1 100F O2 analyzer wiring diagram ..................................................................................13
Figure 5-2 100F O2 electrical schematic .........................................................................................14
Figure 5-3 100F O2 PCB component locator ..................................................................................15
Figure 6-1 Magnetic Susceptibility of gases ...................................................................................18
Figure 6-2 The Measuring cell in theory .........................................................................................18
Figure 6-3 Principle of operation.....................................................................................................19
Figure 7-1 AC Power Switch, Connector, and Fuse .......................................................................20
Figure 8-1 Paramagnetic Oxygen Sample flow ..............................................................................21
Figure 9-1 Oxygen sensor adjustment............................................................................................24
Tables
Table 8-1 Cross Sensitivity of gases...............................................................................................23
Supplemental Manual Oxygen- V7.1.doc
1-4
Section 1
Model 100/200/300 Supplement
Part 1 – Oxygen by Chemical Fuel Sensor Techniques
Supplemental Manual Oxygen- V7.1.doc
1-5
Section 1
1.
Model 100/200/300 Supplement
FUEL CELL DETECTOR OPTION
1.1.
Description Fuel Cell Detector Option
The fuel cell option utilizes a low cost replaceable fuel cell to determine the percent level of
oxygen contained in the sample gas. A fuel cell analyzer features linear output with low noise
and excellent repeatability from 0 to 100% O2.
It is available in two versions, one for oxygen levels up to 25 % and the second for oxygen up
to 100%.
Warning: This is a general-purpose analyzer, not suitable for hazardous areas. Highpressure oxygen is very dangerous. Virtually any material will burn in it, possibly
explosively. It is essential that persons using this analyzer are aware of the dangers of
oxygen, and take all appropriate precautions.
1.2.
Product Specifications (Galvanic Fuel Cell Detector)
SAMPLE CONTACT MATERIAL: Stainless
steel, Teflon* and Tygon**
DISPLAY: 3 ½" digit panel meter
RANGES: Standard fixed ranges, either A
or B
OUTPUTS: 0 to 10 VDC and 4 to 20 mA (0
to 20 mA)
A) Range 1: 0 to 5%; Range 2: 0 to 10%;
Range 3: 0 to 25%
AMBIENT TEMPERATURE: 5 to 45° C
B) Range 1: 0 to 25%; Range 2: 0 to 40%;
Range 3: 0 to 100%
SAMPLE TEMPERATURE: 0 to 50° C
SAMPLE CONDITION: Particles < 1µ, noncorrosive dry gas
RESPONSE TIME: 90% full scale in 5
seconds
FITTINGS: ¼" tube
NOISE: Less than 1% full scale
SAMPLE FLOW RATE: 0.5 –2.0 L/Min
LINEARITY: Better than 1% full scale
Power Requirements: 115/230 (± 10%)
VAC, 50/60 Hz, 70 watts/channel
REPEATABILITY: Better than 1% full scale
Relative Humidity: Less than 90% R.H.***
ZERO SPAN DRIFT: Less than 1% full
scale in 24 hours
ZERO & SPAN ADJUSTMENT: Ten turn
potentiometer
Specifications subject to change without notice
*Teflon is a registered trademark of DuPont.
**Tygon is a registered trademark of the Norton Performance Plastics Corporation
***Non-condensing
Supplemental Manual Oxygen- V7.1.doc
1-6
Section 1
1.3.
Model 100/200/300 Supplement
Principle of operation
The fuel cell option is designed to measure percent levels of oxygen. The analyzer uses a
galvanic fuel cell, which is an electrochemical transducer. The fuel cell contains a cathode,
anode, and an electrolyte. A permeable membrane holds the electrolyte in the cell. The
sample flows over the membrane and oxygen diffuses in to the fuel cell where it reacts with the
electrolyte. This reaction produces an electrical current. This current is directly proportional to
the concentration of oxygen in the gaseous mixture surrounding the cell. The current output is
linear with an absolute zero. The fuel cell produces no current in the absence of oxygen.
1.4.
Oxygen Fuel Cells
The standard oxygen sensor (type PSR-39-11) has a shelf life of approximately three
years. It is designed to measure oxygen in ambient air. The other gases contained in
ambient air are low enough concentrations so as not to be a factor of concern. When used
for ambient air measurement the manufacturer estimates the life of the sensor to be
approximately three years.
If the standard PSR type sensor is used to measure pure oxygen, oxygen in flue gas or
oxygen in stack emissions the life of the standard PSR type sensor will be shorter.
One of the most common emission gases is CO2 and is usually found in concentrations of
between 4-20 percent by volume. High levels Of CO2 change the pH of the gel and thus
shorten the life of the standard PSR type sensor. The life expectancy dramatically shortens
from three years to approximately four weeks at CO2 concentrations of 20% volume.
For the reason stated above, sensor type XLT-39-11 was developed. The XLT type sensor
has an electrolytic gel that is strongly buffered and highly caustic. A caustic gel is required
to combat the effects of high CO2 concentrations. The average life of this type of sensor is
approximately eight to ten months at CO2 levels of 20% by volume; however, the caustic
nature of the electrolytic gel creates vapors that clog the cell membrane within a very short
time if the cell is not put into immediate use. The shelf life of this type of sensor is
approximately two weeks if not stored at a cold, constant temperature. A shelf life of 30
days or so can be achieved if the sensor is kept refrigerated.
As previously stated the XLT-39-11 sensor was developed for use in sample gases
containing high levels Of CO2 (approximately 20% volume. or greater). It provides a longer
life at high CO2 levels, but the linearity of response has been sacrificed. Typical linearity
with this type of sensor is within ± 1% Volume O2.
Because of the non-linearity issue, a third type of sensor was developed. Type
XLT-39-11-1 provides a signal that is linear to within ± 0.25% volume O2. This sensor has
an average life of eight to ten months at medium CO2 levels of 10% by volume. Levels of
CO2 at 20% by volume will shorten the life of this sensor to approximately 3-4 months. The
shelf life of this sensor is similar to the XLT-39-11.
Supplemental Manual Oxygen- V7.1.doc
1-7
Section 2
2.
Model 100/200/300 Supplement
Preparations for Operation
Warning: This is a general-purpose analyzer, not suitable for hazardous areas. Highpressure oxygen is very dangerous. Virtually any material will burn in it, possibly
explosively. It is essential that any persons using this analyzer are aware of the dangers
of oxygen, and take all appropriate precautions.
2.1.
Power On
Turn ON the power switch located on the rear panel. The digital panel meter should illuminate.
Allow the instrument to warm up for approximately 10 minutes. It is preferable, but not
essential, that zero gas flow through the instrument during warm-up.
I
0
Figure 2-1 AC Power Switch, Connector, and Fuse
2.2.
Zero Adjustment
Zero Adjustment: After the 10 minute warm-up period, flow nitrogen or other zero gas through
the instrument at a rate of about 1 liter/min. After the reading stabilizes, adjust the zero control
on the front panel until the digital meter (or analog output) is exactly at zero. Nitrogen is the
preferred zero Gas.
2.3.
Span Adjustment
Span Adjustment: Flow span gas through the instrument at about 1 liter/min. After the reading
stabilizes, adjust the span control on the front panel until the digital meter or analog output is
reading the value corresponding to the span gas concentrations.
Note: Span gas concentration should not be less than 80% of the range to be spanned.
Note: On the 0-25% range of the analyzer ambient air may be used as span gas. While
ambient air is flowing to the analyzer, adjust the span potentiometer to 20.9% O2.
2.4.
Start-Up & Routine Maintenance
Prepare and check the sample system. Adjust the flow of sample gas to about 1 liter/min.
Select an operating range that is suitable for the oxygen concentration of the sample. The
instrument should show a meter indication. The analyzer is designed for extended operation
and may be left switched ON continuously.
2.5.
Zero and Span Calibration Frequency
The zero and span levels should be checked and/or calibrated daily or as often as mandated.
Supplemental Manual Oxygen- V7.1.doc
2-8
Section 3
3.
Model 100/200/300 Supplement
ADJUSTMENTS CHECKS AND REPAIRS
Note: A millivolt generator is required for this procedure.
3.1.
Electrical Zero Adjustments
a) Disconnect the plug (P3) from J3 on the printed circuit board (PCB). (P3 is on the end of
the cable assembly coming from the oxygen sensor.)
b) Connect a millivolt generator between pin no. 1 (-) and pin no. 2 (+) at J3 on the PCB.
c) Adjust simulator for 000.00 mv ± 0.01 mv input as measured at TP-8 (+) and common (-).
d) Adjust Front panel zero potentiometer for 000.00 mv ± 0.01 mv as measured between
TP-9 and common
e) Set front-panel range switch to Range 1.
f)
Adjust R8 for 000.00 mv ± 0.01 mv as measured at TP-4.
g) Adjust R12 for 0.000 VDC ± 0.001 VDC as measured between the 0-10 VDC (+) output
terminal and common.
h) Adjust R20 for 4 mA ± 0.01 mA across the 4-20 mA output terminals.
i)
Verify O2 display reads 000.0 for all ranges.
j)
Repeat steps a) through j) until no further adjustment is required.
3.2.
Electrical Span Adjustments
Note: Electrical zero adjustments must be made before electrical span adjustments.
a)
Adjust the millivolt generator and the front-panel span-potentiometer (as necessary) for
exactly 50.00 mv as measured between TP-9 and common.
b)
Set front-panel range switch to range 1.
c)
Set O2 display selector switch (SW2) to percent (%) O2 mode. Display should read 5.0.
d)
Adjust R4 for 1.000 VDC ± 0.001 VDC as measured at TP-4.
e)
Set range switch to Range 2 and adjust R3 for 0.500 VDC ± 0.001 VDC at TP-4.
f)
Set range switch to Range 3 and adjust R32 for 0.200 VDC ± 0.001 VDC at TP-4.
g)
Set range selector to range 1 and verify 1.000 VDC ± 0.00 VDC at TP-4.
h)
Adjust R33 for 10.00 VDC ± 0.01 VDC as measured across the 0-10 VDC output
terminals.
i)
Adjust R24 for 20 mA ± 0.01 mA as measured between the 4-20 mA output terminals. at
TP-4
j)
Repeat steps a) through j) until no further adjustment is required.
Note: the voltages given in steps e) and f) assume the analyzer is configured for the
standard ranges of 0-5, 10, and 25% O2. Consult the factory for the correct voltages
required for other non-standard range configurations.
Supplemental Manual Oxygen- V7.1.doc
3-9
Section 3
3.3.
Model 100/200/300 Supplement
The Oxygen Sensor
The output of the oxygen sensor is a DC output of approximately –10 millivolts at 20.9 % O2.
As the sensor is used, it gradually becomes consumed and its voltage output slowly
diminishes towards 0 millivolts. Periodic zero and span calibration should be preformed to
insure accurate oxygen measurement over the sensor’s life span. Whenever the front panel
span potentiometer runs out of adjustment capability it will be necessary to perform a coarsespan-adjustment.
3.3.1. Coarse-Span-Adjustment
a) Lift the cover from the analyzer by first removing the retaining screws that secure the cover
to the chassis.
b) Adjust the front panel potentiometer to its mid-setting. The span dial should indicate 5.0.
c) Flow N2 into the analyzer at a flow rate of 1 L/MIN (± 0.5). After the reading stabilizes,
adjust the front panel zero potentiometer for an indication of 0.0% O2.
d) Flow an oxygen span gas into the analyzer at a flow rate of 1.0 L/MIN (± 0.5).
e) Locate R27 on the printed circuit board and adjust it as required to obtain a digital display
that is equivalent to the value of the span gas being used.
3.3.2. Sensor Checks
a) Connect a DC voltmeter to TP-8 (+) and TP-2 common.
b) Introduce a span gas of 21%
c) The measured voltage at TP-8 should be between –3 mv and –13 mv.
d) Whenever the measured voltage is less than –3 mv (or whenever the signal stability
becomes an issue) the sensor should be replaced.
Note: A new sensor has a specification of –10 mv (± 3 mv) when measuring 21% O2 at
sea level. A correction factor (cf) must be applied to this specification whenever the
measuring site is at higher elevations.
Corrected output = −10mv × cf Where : cf =
site barometric pressure (" hg )
30" hg
Where " hg = inches of mercury
3.3.3. Sensor Replacement
a) Refer to section 2.1 of this manual for selection of the proper type of replacement sensor
b) After replacing sensor it will be necessary to perform a coarse-span-adjustment (refer to
paragraph 5.3.1).
Supplemental Manual Oxygen- V7.1.doc
3-10
Section 4
4.
Model 100/200/300 Supplement
Chemical Fuel Cell Sample Flow (Supplemental)
P1
O2 SENSOR
OUT
Fl1
MF1
40
SAMPLE
INLET
NV1
NDIR SAMPLE CELL(s)
IN
MODEL 100F
WITH OPTIONAL FLOWMETER & SAMPLE PUMP
O2 SENSOR
OUT
Fl1
MF1
40
SAMPLE
INLET
NV1
NDIR SAMPLE CELL(s)
IN
MODEL 100F
WITH OPTIONAL FLOWMETER & SAMPLE PUMP
4. IN-LINE FILTER (MF1) CUSTOMER SUPPLIED.
3. INLET & OUTLET CONNECTIONS ARE 1/4” OD TUBE.
2. SAMPLE FLOW RATE: 0.5 L/min to 2.0 L/min.
1. SAMPLE PRESSURE: 1-5 PSIG (NOT REQUIRED WITH OPTIONAL SAMPLE PUMP).
NOTES: UNLESS OTHERWISE SPECIFIED.
Figure 4-1 Chemical fuel cell sample flow
Supplemental Manual Oxygen- V7.1.doc
4-11
Section 5
5.
Model 100/200/300 Supplement
Electrical Drawings
ƒ
Figure 5-1 100F O2 analyzer wiring diagram
ƒ
Figure 5-2 100F O2 electrical schematic
ƒ
Figure 5-3 100F O2 PCB component locator
Supplemental Manual Oxygen- V7.1.doc
5-12
Supplemental Manual Oxygen- V7.1.doc
6
ZERO
7
5
GY
BL
CCW
S
+
C
NO NO
C
NC NC
RD
GR
BK
BK
PUMP SWITCH (OPTIONAL)
S5
CW
R37 100k Ω
YL
OR
S
SPAN
BR
RD
RD
GR
GR
BL
WH
VI
CCW
R38 20k Ω
CW
8
RANGE SWITCH
S4
R1
R2
1
12
R3
RMT 11
2
10
3
C
RMT
A
9
4
PANEL METER
J10 P10
HI 1
LO 2
GND 3
COM 4
HOLD3 5
DECIMAL 102 6
POINT 101 7
10 8
POWER 0V 9
+5V 10
METER
P9 J9
1
2 PUMP LED
P8 J8
1
2 PUMP SWITCH
1
2
3
4 ZERO/SPAN
5
6
P4 J4
1 2 3
J7 P7
1
PUMP 2
J1 P1
1
115 VAC 2
3
J6 P6
1
OUTPUTS 2
3
4
SENSOR
P3
1 2 J3
OXYGEN ANALYZER PCB
110010
P5
1 3 5 7 9 J5
2 4 6 8 10
1
2
3
4 RANGE
5
6
7
8
P2 J2
YL
BR
GY
10 CNDCT
RIBBON CABLE
SENSOR
BK
RD
FRONT PANEL
BK
BK
GR
PUMP (OPTIONAL)
G
C
B
A
GR
GR
D
GR
E
F
WH
BK
H
J
REAR PANEL
S3
GR
BR
RD
GY
YL
OR
RD
BR
BK
J10
1
2
3
4
5
6
7
8
9
10
11
12
OUTPUT CONNECTOR
CHASSIS GND
F1
1A
POWER ENTRY MODULE
R2
R3
GND
+15V RMT
GND
+
0–10 VDC
–
+
4–20 mA
–
N
G
H
Section 5
Model 100/200/300 Supplement
Figure 5-1 100F O2 analyzer wiring diagram
5-13
Supplemental Manual Oxygen- V7.1.doc
1
2
J3
1
2
3
4
5
6
7
8
J2
RANGE
1
2
J9
1
2
J8
1
2
J7
115VAC
1
2
3
F
TP8
DRO
DRR
DR1
RTN
IG ND
+15V
RO
R1
F
F
R25
10K
R35
1.5K
F
R1
1 MEG
HOT
NEUTRAL
G RO UND
+15V
C28
.01
200V
120Ω
5
2
F
+15V
F
R26
10K
C19
.1
SHOWN IN 115VAC
POSITION
SW1
4
6
3
1
2
3
+15V
7
–
U11
+
4
–15V
1
6
OP07
8
C20
.1
6
4
3
1
F
D3
1N4002
D2
1N4002
12
10
9
7
T1
14A–10–36
F
C21
.1
+15V
F
F
2
3
1
2
3
1
C22
.1
K2
K1
2 –
4
4
C23
.01
CW
R32
10K
R31
30K
3
4
R4
20K
R2
162K
500K
R27
TP9
D1
+ 1
D5
5.6V
CW
CT
CCW
1
2
3
4
5
6
J4
F
2
+15V
7
–
U6
+
4
2
1
6
F
TP1
G
N
D
V0
V0
C9
.1
F
1
2
3
4
5
6
7
J5
R8
10K
1
9
10
OUT
F
9
O
U
T
A
2
O
U
T
A
1
8
F
1
4
C
O
M
O O
F F
A A
D D
J J
6
–15V
1
3
–
V
C
C
+
V
C
C
2
R13
402
F
C17
.1
TP3
TP1
CW
+15V
C6
.1
C5
.1
7
R20
2K
R21
8.2K
R22
6.81K
D4
LM336–5.0
1
2
3
3
M
E
T
E
R
R23
3K
U10
INA101
+15V
LM120T–15
U2
V1
2
G
N
D
U1
LM340AT–15
V1
CW
OP07
8
C4
.1
C3
.1
–15V
C18
.1
SW2
3
2
C25
.1
R3
20K
ZERO/SPAN
F
+5V
3
%02
F
R5
91K
R6
10K
CW
C2
100 UF
50V
1
R30
6.8K
+
C1
330 UF
50V
02FS
+15V
F
R7
10K
CW
F
+
1
8
J1
R9
2K
C11
.1
+ IN
GSEN2
GSET2
GSET1
GSEN1
– IN
5
4
3
C16
.1
R10
2K
F
12
11
F
F
3
2
R18
1K
1%
F
R14
499
R33
100K
F
18K
R11
CW
YELLOW
LED2
GREEN
10
+15V
TP5
R24
2K
CW
TP4
1.5K
R29
1.5K
R28
LED1
4
1
6
1
6
R19
10K
1%
F
C11
.1
C10
.1
V0
F
C24
.1
2
3
1
A
D
J
F
C8
.1
VI
1
2
3
4
J5
–15V
+15V
+5V
3
F
+15V
OUTPUTS
C14
.1
R15
100
U9
LM317T
VO
R17
33
TP6
C12
.1
CW
F
F
R12
10K
+15V
TP2
2
G
N
D
U3
LM7805CT
V1
OP07
8
C13
.1
OP07
8
+15V
7
–
U7
+
R34
124
+15V
7
–
U8
+
4
–15V
3
2
C26
.1
–15V
C7
.1
1
Section 5
Model 100/200/300 Supplement
Figure 5-2 100F O2 electrical schematic
5-14
Supplemental Manual Oxygen- V7.1.doc
C27
6
4
3
1
3
115
1
VAC
T1
1
5W1
J7
2
1
VAC
230
VAC
115
12
10
9
7
R1
2
D1
2
+
I
U2
C8
R28
J8
LED1
TP2
+
C2
C4
C6
U3
C7
TP1
TP3
J9
1
C5
R29
R21
R19
U9
R35
U10
D4
C24
R22
C1
C3
U1
C17
R34
LED2
C15
C14
1
C16
R20
C11
R11
J6
OUTPUTS
C26
J1
J5
R9
R24
D5
R10
C18
R23
R13
R3
C25
R12
C13
U8
C12
R14
R16
C10
METER
R18
U7
4
R33
TP5
TP4
TP7
K1
C22
C19
TP9
TP8
C23
1
U11
K2
R32
RANGE
J2
OXYGEN FUEL CELL
410175
R4
D2
C9
R30
TP6
R7
R5 R2
R8
U6
R6
R25
2
FS
SW2
8
SENSOR
J3
2
1
6
1
J4
ZERO/SPAN
2
R27
D3
R31
C20
C21
R26
Section 5
Model 100/200/300 Supplement
Figure 5-3 100F O2 PCB component locator
5-15
C28
Section 6
Model 100/200/300 Supplement
Part 2 – Oxygen by Paramagnetic Oxygen Sensor Techniques
Supplemental Manual Oxygen- V7.1.doc
6-16
Section 6
6.
Model 100/200/300 Supplement
PARAMAGNETIC OXYGEN OPTION
6.1.
Description
The Paramagnetic Oxygen detector is a thermostated device designed primarily for but not
necessarily limited to stationary use. It is a ‘19” rack mount analyzer that is also suitable for
bench top use. The operation of the analyzer is based upon the principle of the magnetodynamic oxygen cell, which is the most accurate and reliable cell for determining the oxygen
content of a gas mixture from 0-100 volume percent oxygen.
Warning: This is a general-purpose analyzer, not suitable for hazardous areas. Highpressure oxygen is very dangerous. Virtually any material will burn in it, possibly
explosively. It is essential that any persons using this analyzer are aware of the dangers
of oxygen, and take all appropriate precautions.
6.2.
Product Specifications Paramagnetic Oxygen Detector
SAMPLE CONTACT MATERIAL: Platinum.
glass, stainless steel and Viton, Teflon*
and Tygon**
DISPLAY: 3 ½" digit panel meter
RANGES: Standard fixed ranges, either A
or B or C
OUTPUTS: 0 to 10 VDC and 4 to 20 mA (0
to 20 mA)
A) Range 1: 0 to 1%; Range 2: 0 to 15%;
Range 3: 0 to 25%
AMBIENT TEMPERATURE: 5 to 45° C
B) Range 1: 0 to 5%; Range 2: 0 to 10%;
Range 3: 0 to 25%
C) Range 1: 0 to 25%; Range 2: 0 to 40%;
Range 3: 0 to 100%
SAMPLE TEMPERATURE: 0 to 50° C
SAMPLE CONDITION: Particles < 1µ, noncorrosive dry gas
FITTINGS: ¼" tube
RESPONSE TIME: 90% full scale in 2
seconds
NOISE: Less than 1% full scale
SAMPLE FLOW RATE: 0.5 –2.0 L/MIN
LINEARITY: Better than 1% full scale
Power Requirements: 115/230 (± 10%)
VAC, 50/60 Hz, 70 watts/channel
REPEATABILITY: Better than 1% full scale
Relative Humidity: Less than 90% R.H.***
ZERO SPAN DRIFT: Less than 1% full
scale in 24 hours
ZERO & SPAN ADJUSTMENT: Ten turn
potentiometer
Specifications subject to change without notice
*Teflon is a registered trademark of DuPont.
**Tygon is a registered trademark of the Norton Performance Plastics Corporation
***Non-condensing
Supplemental Manual Oxygen- V7.1.doc
6-17
Section 6
6.3.
Model 100/200/300 Supplement
Principle of operation
The paramagnetic susceptibility of oxygen is significantly greater than that of other common
gases, and consequently, the molecules of oxygen are attracted much more strongly by a
magnetic field than the molecules of the other gases. Most of the other gases are slightly
diamagnetic which means that their molecules are then repelled by a magnetic field.
Figure 6-1 Magnetic Susceptibility of gases
The principle of the magneto-dynamic cell is based upon Faraday's method of determining the
magnetic susceptibility of a gas. The cell consists of two nitrogen-filled quarts spheres
arranged in the form of a dumbbell. A single turn of platinum wire is placed around the
dumbbell that is suspended in a symmetrical non-uniform magnetic field.
Figure 6-2 The Measuring cell in theory
Supplemental Manual Oxygen- V7.1.doc
6-18
Section 6
Model 100/200/300 Supplement
When the surrounding gas contains oxygen, the dumbbell spheres are pushed out of the
magnetic field by the change in the field that is caused by the relatively strong paramagnetic
oxygen. The torque acting on the dumbbell will be proportional to the paramagnetism of the
surrounding gas and, therefore, it can be used as a measure of the oxygen concentration.
The distortion of the dumbbell is sensed by a light beam and projected on a mirror attached to
the dumbbell whereof it is reflected to a pair of photocells. When both photocells are
illuminated equally, the output will be zero. The output from the photocells is connected to an
amplifier, which in turn is fed to the feedback coil of the measuring cell. If the oxygen content
of the gas sample changes, the corresponding current output of the amplifier, which is
proportional to the oxygen content, produces a magnetic field in the feedback coil opposing the
forces and thereby causing the dumbbell to rotate.
Figure 6-3 Principle of operation
Since the feedback current from the amplifier is proportional to the oxygen content of the gas
sample, the output signals that are produced by the amplifier will be accurate and linear. The
paramagnetic susceptibility of oxygen varies inversely as the square of the absolute
temperature. To provide compensation for changes in analyzer temperature, a temperature
sensitive element in contact with the measuring cell assembly, is included in the feedback
current circuit.
Supplemental Manual Oxygen- V7.1.doc
6-19
Section 7
7.
Model 100/200/300 Supplement
Preparations for Operation
Warning: This is a general-purpose analyzer, not suitable for hazardous areas. Highpressure oxygen is very dangerous. Virtually any material will burn in it, possibly
explosively. It is essential that any persons using this analyzer are aware of the dangers
of oxygen, and take all appropriate precautions.
7.1.
Power On
Turn ON the power switch on the rear panel. The digital panel meters should illuminate. Allow
the instrument to warm up for approximately one hour. It is preferable, but not essential, that
zero gas flow through the instrument during warm-up.
I
0
Figure 7-1 AC Power Switch, Connector, and Fuse
Note: DO NOT introduce the sample gas UNTIL the analyzer has warmed-up. This will
help prevent condensation from forming in the sample cell.
7.2.
Zero Adjustment
After the one-hour warm-up period, flow zero gas (see Section - Gases) through the
instrument at a rate of about 1 liter/min. Adjust the zero control on the front panel until the
digital meter (or analog output) is exactly at zero. To achieve final stability, the analyzer may
require some additional warm-up period/up to four hours (depending on variables in the
analyzer's environment).
7.3.
Span Adjustment
Flow span gas through the instrument at about 1 liter/min. Adjust the span control on the front
panel until the digital meter or analog output is reading the value corresponding to the span
gas concentrations.
Note: Span gas concentration should not be less than 80% of the range to be spanned.
Note: On the 0-25% range of the analyzer ambient air may be used as span gas. While
ambient air is flowing to the analyzer, adjust the span potentiometer to 20.9% O2.
7.4.
Zero and Span Calibration Frequency
The zero and span levels should be checked and/or calibrated daily or as often as mandated.
Supplemental Manual Oxygen- V7.1.doc
7-20
Section 8
8.
Model 100/200/300 Supplement
Start-Up & Routine Operation
Prepare and check the sample system. Adjust the flow of sample gas to about 1 L/min. The
instrument should show a meter indication. The paramagnetic oxygen analyzer is designed for
extended operation and may be left switched ON continuously.
8.1.
Sampling System
Note: High-pressure oxygen is very dangerous. Virtually any material will burn in it,
possibly explosively. It is essential that any person using this analyzer is aware of the
dangers of oxygen, and take all appropriate precautions.
The analyzer's sampling system consists of:
1. An internally mounted in line particulate filter
2. A sample pump and flow meter (optional)
3. A sample capillary that controls the sample flow rate to the sensor at 0.2 LPM (or 0.5
depending upon model of O2 sensor.
4. A precision controlled relief valve.
The relief valve maintains a constant inlet pressure to the sample capillary and reduces
response time by providing a bypass loop to the exhaust for excess sample.
The analyzer is designed to measure a clean dry sample gas that has been conditioned to
remove moisture to prevent condensation in the analyzer. Some applications may require
additional sample conditioning, dependent upon the specifications of the sample gas to be
measured.
P1
C1
O2 SENSOR
OUT
Fl1
MF1
5µ
MF2
40µ
SAMPLE
INLET
NDIR SAMPLE CELL(s)
NV1
RV1
IN
MODEL 100P
WITH OPTIONAL FLOWMETER & SAMPLE PUMP
C1
O2 SENSOR
Fl1
MF1
5µ
MF2
40µ
SAMPLE
INLET
OUT
NDIR SAMPLE CELL(s)
NV1
IN
RV1
MODEL 100P
WITH OPTIONAL FLOWMETER
4.IN-LINE FILTER (MF2) CUSTOMER SUPPLIED.
3.INLET & OUTLET CONNECTIONS ARE 1/4” OD TUBE.
2.SAMPLE FLOW RATE: 0.5 L/min to 2.0 L/min.
1.SAMPLE PRESSURE: 3-5 PSIG (NOT REQUIRED WITH OPTIONAL SAMPLE PUMP).
NOTES: UNLESS OTHERWISE SPECIFIED.
Figure 8-1 Paramagnetic Oxygen Sample flow
Supplemental Manual Oxygen- V7.1.doc
8-21
Section 8
8.2.
Model 100/200/300 Supplement
Cross sensitivity of gases
The paramagnetic measuring principle is based on the very high magnetic susceptibility of
oxygen. In comparison to oxygen, other gases have such a minor susceptibility that most of
them are insignificant. Exceptions to this are the nitrogen oxides. However, as this gas is in
most cases present in a very low concentration, the error is still negligible.
8.2.1. Example 1
The residual oxygen percentage is measured in a closed carbon dioxide (CO2)
atmosphere. The "zero calibration" is done by means of nitrogen (N2).
According to the list of cross-sensitivities, the error for 100 % CO2 at 200°C is -0.27%. In
order to obtain a higher accuracy, this means for the zero calibration that the reading
should be adjusted at +0.27% with N2, in order to compensate the error of CO2.
Since the values of cross-sensitivities are based on 100 Volume percentage of that
particular gas, the error at 50% by volume CO2 and 50% by volume N2 is - 0.135%.
8.2.2.
Example 2
Given the following gas composition at a temperature of 20° C:
5% volume Oxygen (O2)
40% volume Carbon Dioxide(CO2)
1% volume Ethane(C21-14)
54% volume Nitrogen (N2)
+100.00 x 10-2 x 5 =
+5.0000
-2
-0.27 x 10 x 40 =
-0.1080
-0.43 x 10-2 x l =
-0.0043
-2
0.0000
0.00 X 10 x 54 =
Gives a reading (%by volume) of:
+4.8877
As this example shows, the total error (5.000 minus 4.8877) is - 0.1123.
Supplemental Manual Oxygen- V7.1.doc
8-22
Section 8
Model 100/200/300 Supplement
Table 8-1 Cross Sensitivity of gases
All values based on nitrogen 0% / oxygen 100%
Gas
Argon
Acetylene
Acetone
Acetaidehyde
Ammonia
Benzene
Bromine
Butadiene
Isobutylene
n-Butane
Chlorine
Hydrogen Chloride
Nitrous Oxide
Diacetylene
Ethane
Ethylene Oxide
Ethylene
Ethylene Glycol
Ethylbenzene
Hydrogen Fluoride
Furan
Helium
n-Hexane
Krypton
Carbon Monoxide
Carbon Dioxide
Methane
Methanol
Methylene Chloride
Neon
n-Octane
Phenol
Propane
Propylene
Propene
Propylene Oxide
Propylene Chloride
Silane
Styrene
Nitogen
Nitrogen Monoxide
Nitrogen Dioxide
Oxygen
Sulfur Dioxide
Sulfur Fluoride
Hydrogen Sulfide
Toluene
Trichloroethylene
Vinyl Chloride
Vinyl.Fluoride
Water
Hydrogen
Xenon
Formula
Ar
C2H2
C3H60
C2H4O
N3
C6H4
Br2
C4H6
(CH3)2CH=CH2
C4H10
CL2
HCL
N2O
(CHCl)2
C2H4
C2H4O2
C2H4
CH2OHCH2OH
C8H10
HF
C4H40
He
C6H14
Kr
CO
CO2
CH4
CH4O
CH2Cl2
Ne
C8H18
C6H6O
C3H8
C3H6
CH3CH=CH12
C3H6O
C3H7Cl
SiH4
C7H6=CH2
N2
NO
NO2
O2
SO2
SF6
H2 S
C7H8
C2HCl3
C2H3CI
CH3F
H2O
H2
Xe
Supplemental Manual Oxygen- V7.1.doc
20oC
-0.23
-0.26
-0.63
-0.31
-0.17
-1.24
-1.78
-0.85
-0.94
-1.10
-0.83
-0.31
-0.20
-1.09-0.43
-0.54
-0.20
-0.78
-1.89
+0.12
-0.90
+0.29
-1.78
-0.49
-0.06
-0.27
-0.16
-0.27
-1.00
+0.16
-2.45
-1.40
-0.77
-0.57
-0.58
-0.90
-1.42
-0.24
-1.63
-0.00
+42.70
+5.00
+100.00
-0.18
-0.98
-0.41
-1.57
-1.56
-0.68
-0.49
-0.03
+0.23
-0.95
50oC
-0.25
-0.28
-0.69
-0.34
-0.19
-1.34
-1.97
-0.93
-1.06
-1.22
-0.91
-0.34
-0.22
-1.20
-0.47
-0.60
-0.22
-0.88
-2.08
+0.14
-0.99
+0.32
-1.97
-0.54
-0.07
-0.29
-0.17
-0.31
-1.10
+0.17
-2.70
-1.54
-0.85
-0.62
-0.64
-1.00
-1.44
-0.27
-1.80
-0.00
+43.00
+16.00
+100.00
-0.20
-1.05
-0.43
-1.73
-1.72
-0.74
-0.54
-0.03
+0.26
-1.02
8-23
Section 9
9.
Model 100/200/300 Supplement
Mechanical Zero Adjustment (Not required with some sensor models)
This adjustment depends upon sensor model and may be periodically required over the
life span of the analyzer, or whenever the front panel zero adjustment has reached its
limit.
Note: Always check for gas leaks prior to making this adjustment, especially when the
zero potentiometer is at its counter-clockwise limit.
a) Place the front panel zero adjustment to its mid-setting (5.0 on the dial.)
b) Introduce N2 into the analyzer at a flow rate of 0.5-2.0 L/MIN.
c) Remove the screws securing the top to the chassis and lift off the cover of the analyzer
d) Locate and remove the rubber ‘boot’ that covers the O2 sensor.
e) Loosen the locking screw that secures the adjusting screw for positing the photo-sensor on
the detector assembly. Only loosen the locking screw enough to permit the necessary
adjustment (see Figure 8-1.)
f) Turn the adjusting screw as required to give an indication of approximately 0.00 on the
digital display.
g) Carefully tighten the locking screw and replace the rubber ‘boot’ removed in step d).
h) Observe the digital display and turn the front panel zero adjustment to achieve reading of
0.00 in the display.
i) The zero adjustment should be between 4.0 and 6.0 on its dial. If not, repeat steps d)
though h) until no further adjustment is required.
Photo Detectors
Circuit Board
Photo Detector
Mounting Block
Locking Screw
Loosen
Adjust
Adjusting Screw
Figure 9-1 Oxygen sensor adjustment
Supplemental Manual Oxygen- V7.1.doc
9-24