The purpose of this test is to determine the integrity of each filter shipment by spot testing random statistical samples prior to filter installation.

INSTRUMENTATION AND EQUIPMENT

  • An aerosol photometer, aerosol generator and scanning probe.

or

  • A particle counter, microsphere generator and scanning probe.

 

  • A test bench with a fan capable of delivering the specified airflow volume of the installed filters. The fan shall be capable of supplying the air in a uniform manner upstream of the face of filters. The bench filter seal must prevent excessive aerosol from escaping into the environment

TEST PROCEDURE

  • Test every filter, or if owner approved, develop a statistical sample based on the following:
  1. Test all filters which show signs of damage
  2. Test every fifth filter and upon failure, test additional untested filters.
  • Provide flow test bench, aerosol photometer and oil generator (either Laskin nozzle or thermal) or
  • optical laser particle counter, and microsphere generator and a particle controlled environment.
  • Introduce aerosol oil challenge or microsphere challenge upstream of the filter. A minimum challenge shall be 10μg/l of oil or at least 210,000,000 particles per cubic meter (6,000,000 particles per cubic foot).
  • Measure the upstream challenge of each filter.
  • Scan the entire downstream filter face area in overlapping strokes, moving at the calculated scan rate spaced a distance of 25 mm (1 inch) from the filter face.
  • Repairs, leaks and retesting of filters shall be performed in accordance with the requirements.

FIND MORE AT…

Reference links

http://www.isu.edu.tw/upload/81201/45/news/postfile_23270.ppt

https://www.cleanroomtechnology.com/technical/article_page/Integrity_testing_of_HEPA_filters/51404