Aerosol Particle Generator a PSL Sphere Particle Generator provides a particle challenge to ULPA filters and HEPA filters. Polystyrene Latex spheres are used as a particle challenge to create an upstream particle challenge to measure filter particle efficiency across the downstream side of the ULPA and HEPA filters. Pin hole leaks can also be detected on the downstream using the proper scanning equipment across the filter surface. HEPA filters provide 4/9 and 5/9 filter efficiency, while ULPA filters offer 6/9 and 7/9 filter efficiency. The Model 2045 Particle Generator easily meets the upstream particle challenge, producing 7.2×10 E10 at 0.10μm particles per minute. Polystyrene Latex spheres at 0.3μm are used to challenge HEPA filters and detect pin hole leaks, while Polystyrene Latex spheres at 0.15μm or 0.12μm are used to challenge ULPA filters and detect pin hole leaks.
The upstream particle count of the filter challenge generally mixed with a filtered, air source. A 6/9 ULPA filter has the capability to trap 99.9999% of all particles flowing through the filter, which is 1/1,000,000. So a very high particle count is needed in the range of 1E10 particles per minute at 0.1 micron to 0.2 micron. HEPA filters require less particle challenge to sustain the upstream particle challenge. A PSL Sphere Particle Generator uses Polystyrene Latex spheres, mixed with the appropriate amount of airflow, generally from 700cfm to 2000cfm. A uniform airflow is needed to be supplied to the upstream side of the filter.