The Article entitled Filters Under Test appearing on CleanroomTechnology.com October 6, 2006 is a simple to the point explanation of Hepa filter integrity testing using the aerosol photometer testing method. It’s easy to understand to the point and a quick read. It can be found by following the link below:
https://www.cleanroomtechnology.com/technical/article_page/Filters_under_test/51442