CORRELATION OF ALTERNATIVE AEROSOLS AND TEST METHODS FOR HEPA FILTER LEAK TESTING

摘要

Alternatives to the traditional method of HEPA filter leak testing using DOP (di-(2-octyl)-phthalate) as test aerosol and an aerosol photometer for penetration measurement were investigated. DEHS (di-(2-ethylhexyl)-sebacate) and PAO (4 cSt Poly-alpha-olefin) proved to be less toxic alternatives to DOP. Correlation studies were performed using the controlled leak test method of D. R. Moore et al. Both alternative aerosols offer a satisfactory correlation with DOP. The same test method was used for correlating the Discrete Particle Counter (DPC) method with the Aerosol Photometer (AP) method. The correlation of both alternative methods is good, the DPC method providing constantly higher penetration rates than the AP method. In summary, the DPC method requires a lower aerosol concentration, besides affording better resolution and broader application.