Effect of aerosol concentration and particle size on particle counting leak test of HEPA filters

Aiming at the problem of different recommendations on aerosol concentration and particle size for HEPA filter scanning leak test in different standards and codes at home and abroad, by establishing the particle counting scanning leak test bed, tests the local penetration ratio of HEPA filter under the conditions of different upstream aerosol concentration and particle size. Analyses the impact of aerosol concentration and particle size on HEPA filter leak testing results. Experimental results show that when the upstream aerosol concentration of the HEPA filter is stability, the concentration and the particle size have little effect on filtering efficiency. Gives some corresponding recommendations for in-site scanning leak test of HEPA filters.