ATI Aerosol Photometer & Aerosol Generator Basics

NAFA MeetingApril 18, 2012Scottsdale, AZ

ATI Aerosol Photometer Basics

website: website: www.ATItest.comwww.ATItest.comemail: email: info@ATItest.cominfo@ATItest.com

phone: 410-363-9696phone: 410-363-9696

Dave Crosby dcrosby@atitest.comTony Hawkins ahawkins@atitest.comDon Largent dlargent@atitest.com

Topics

• 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

• Types of Aerosols• Aerosol Size• Laskin Nozzle Type• Thermal Inert Gas Type• Generator Capacities & Concentration

Two Types of Aerosol 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 13,500Total Flow (cfm)

Polydisperse Thermal (vapor condensation) Aerosol Generator (inert gas)

Thermal Generator Operation

Generator CapacitiesDescription 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

Aerosol Type Polydispersed (cold)

Polydispersed (cold)

Polydispersed (cold)

Polydispersed (hot)

Size L x H x W L x H x W L x H x W L x H x W

Inches (in) 10in x 8in x 9in 11in x 10in x 11in 14.5in x 9in x 10in 14in x 10in x 10in

Weight-Pounds (lbs) 12 lbs 16 lbs 34 lbs 23 lbs

Electrical (Not Required) (Not Required) 110 or 220VAC 110 or 220VAC

*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• 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

• 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

• 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 componentsFramesGasketsFilters

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• 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

• Nuclear Air Cleaning Handbook• NEBB Cleanroom Guide• IEST Standards• Various Manufacturers Literature and

websites• International Air Cleaning Conference

Proceedings