The purpose of the total aerosol penetration test method is to verify filter and installation integrity when downstream access to the filter and installation is not accessible.  This test is performed by introducing challenge aerosol upstream of filters installed in ducts remote to the cleanroom. The filtered air entering the room from the duct is then measured and compared to the upstream concentration to determine the overall penetration of the filter installation.

INSTRUMENTATION AND EQUIPMENT

  • An aerosol particle generator.

TEST PROCEDURES

  • Introduce a minimum of 10 μg/L of the aerosol challenge upstream of the filters in a manner that will produce a uniform challenge to the filter bank.
  • Using a photometer on its 100% scale, probe the duct and measure the aerosol concentration in the duct directly upstream of the filters.
  • Multiple points should be read across a plane closest to the filter in order to determine whether or not a uniform concentration is achieved.
  • A minimum of five evenly spaced readings should be taken and all individual readings should fall within ±5% of the average in order to continue.
  • If any individual reading deviates greater than ±5% of the average, then another location must be found for the introduction of aerosol such that it will meet the uniformity requirements.
  • Locate a place in the ductwork at least ten duct diameters from the filters under test.
  • Using a photometer set to a scale which will measure 0.030% concentration, probe the duct and measure the aerosol concentration penetration.
  • Multiple points should be read across a plane in order to determine whether or not a uniform concentration is achieved.
  • A minimum of five evenly spaced readings should be taken and all individual readings should fall within ±5% of the average in order to continue.
  • If any individual reading is deviates greater than ±5% of the average, then another location must be found for the downstream reading of aerosol penetration such that it will meet the uniformity requirements.

 

ACCEPTANCE:- The downstream measured aerosol concentration should not exceed 0.030% of the upstream concentration.

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Reference links

https://www.iso.org/obp/ui/#iso:std:iso:14644:-3:ed-1:v1:en

https://www.osti.gov/scitech/servlets/purl/325065