ATI Aerosol Photometer &
Aerosol Generator Basics
NAFA Meeting
April 18, 2012
Scottsdale, AZ
ATI Aerosol Photometer Basics
website: www.ATItest.com
email: info@ATItest.com
phone: 410-363-9696
Dave Crosby
Tony Hawkins
Don Largent
dcrosby@atitest.com
ahawkins@atitest.com
dlargent@atitest.com
Topics
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Basic HEPA Filtration System
Aerosol Generator Basics
Photometer Basics
HEPA Filter Testing
Summary
Standards and help resources
Objectives of Session
• Explain basic HEPA filtration components
• Describe “in-situ” test techniques
• Detail aerosol generator design and
operation
• Describe components and functions of the
photometer
• Differentiate between efficiency and leak
testing of HEPA filters
Basic HEPA Filtration System
HEPA System Examples
Aerosol Generators
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Types of Aerosols
Aerosol Size
Laskin Nozzle Type
Thermal Inert Gas Type
Generator Capacities & Concentration
Two Types of Aerosol
• Monodisperse or Near- Monodisperse
• Polydisperse
Near-Monodisperse Aerosol
Polydisperse Aerosol
Aerosol Size 0.3 Micrometer
Monodisperse Aerosol
Penetrometer (i.e. Filter Tester)
Polydisperse Laskin Nozzle
Aerosol Generators
Polydisperse Laskin Nozzle
DOP Output of Laskin Nozzle
• NRL Report 5929, Echols & Young, pg. 16,
Appendix A, Model III-A (4 jets)
• 20 psig @ 75 lpm @ 5.1 mg/l
• 75 lpm X 5.1 mg/l = 382.5 mg/min DOP
• Output mixed with 135 cfm of air produces
a concentration of 100ug/l
Calculate Aerosol Challenge
Concentration (µg/l)
Laskin Nozzle
Number Nozzles X 13,500
Total Flow (cfm)
Polydisperse Thermal (vapor condensation)
Aerosol Generator (inert gas)
Thermal Generator Operation
Generator Capacities
Description
TDA-4Blite
TDA-4B
6D
5C
Aerosol Output Range
50-4,050 cfm
50-8,100 cfm
50-2,000 cfm
1,500-65,000 cfm
Aerosol Concentration 100µg/l @
405 cfm*
810 cfm*
200 cfm*
6,500 cfm
Aerosol Concentration 10µg/l @
4,050 cfm*
8,100 cfm*
2,000 cfm*
65,000 cfm
Generator Type
1 to 3 Laskin
Nozzles
1 to 6 Laskin
Nozzles
2 or 6 Laskin
Nozzle Jets
Thermal (Vapor
Condensation)
Compressed Gas
3 to 9 cfm @ 20
psi
3 to 18 cfm @ 20
psi
(Not Required)
Inert Gas
Polydispersed
(cold)
Polydispersed
(cold)
Polydispersed
(cold)
Polydispersed
(hot)
LxHxW
LxHxW
LxHxW
LxHxW
10in x 8in x 9in
11in x 10in x 11in
14.5in x 9in x 10in
14in x 10in x 10in
12 lbs
16 lbs
34 lbs
23 lbs
(Not Required)
(Not Required)
110 or 220VAC
110 or 220VAC
Aerosol Type
Size
Inches (in)
Weight-Pounds (lbs)
Electrical
*When operated at 20 psi
Generator Applications
• Monodisperse Penetrometer used at the factory and DOE Filter Test
Facility (ATI Filter Test Laboratory):
EFFICIENCY Testing
• Polydisperse Aerosol Generators and
Photometers:
In-Place Filter Leak Testing
Photometers
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Forward Light Scattering
Photometer Flow Diagram
Photometer Components Digital Type
Internal Reference (INT REF)
Light Scattering
Forward Light Scattering
Forward Light Scattering Chamber
Photometers View Particles En Masse
Particle Counter Operation
(One Particle at a time)
Photometer Flow Diagram
Analog Photometer
TDA-2G Digital Photometer
2H Digital Photometer
2i Digital Photometer
Digital Photometer Components
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Selector Valve
% Penetration Display & Bar Graph
Program/Control Key (ENTER)
Scroll UP () & Scroll Down () keys
Function keys (0) (100) (REF) (ALARM)
Upstream & Downstream Connections
Power switch (Ctrl-Alt-DEL)
Fuses & various signal connectors
2i Digital Photometer Features
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Selector Valve – Electronically controlled
Full digital display % Penetration & Flow
Controlled via Probe and Base
Easily navigable menu structure
Power switch and button
Digital Photometer Operation
• Use INT REF to establish 100 ug/l
sensitivity level
• Measure & record upstream challenge
concentration
• Set for 100% with upstream challenge
concentration (100% baseline)
• Set for .000% (0% baseline)
• Test downstream for aerosol leakage
Purpose of INT REF Feature
• To measure upstream challenge
concentration levels directly in ug/l
• To set a photometer to the correct
sensitivity level when an upstream aerosol
challenge sample is unavailable and the
concentration has to be calculated
INT REF on Digital Photometer
Using Calculated Concentration
• Simply scroll to the calculated
concentration
In-Situ Filter Leak Testing
• Performed with Polydisperse Aerosol
• Tests the entire filtration system for
defects
• Checks the following system components
Frames
Gaskets
Filters
SUMMARY
• Efficiency testing done at factory with
Monodisperse aerosol
• Efficiency testing measures penetration
through HEPA filter only
• In-place testing done with Polydisperse
aerosol
• In-place tests complete filtration system
for defects (leaks)
Standards
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IEST RP-001 Filters
IEST RP-002 Laminar Flow Devices
IEST RP-006 Cleanrooms
IEST RP-034 Scanning HEPA Filters
ISO 14644
ASME AG-1 Code
ASME N-511
NSF 49
Where to Get More Information
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Nuclear Air Cleaning Handbook
NEBB Cleanroom Guide
IEST Standards
Various Manufacturers Literature and
websites
• International Air Cleaning Conference
Proceedings