The collection efficiency of nine types of filter papers for air sampling was determined for monodispersed polystyrene latex aerosols by using a forward light scattering photometer. The aerosols were 0.091, 0.198, 0.365, 0.500 and 1.099μm in diameter, which flowed through a test filter paper at a face velocity from 4.2 to 200cm/sec.
Toyo No. 660, No. 60 and No. LP filter papers exhibited minimum efficiencies at the face velocity range between 10 and 80cm/sec, and in the particle size range between 0.1 to 0.5μm. The collection efficiencies of Toyo No. 5A and Whatman No. 41 filter papers were over 95% for all the particle sizes at a face velocity higher than 100cm/sec. Toyo HE-40, HV-70, Toyo GB-100 and Gelman. E filter papers showed the collection efficiencies as high as more than 99%. The theoretical filter efficiency based on single fiber filtering mechanisms and the effect of neighboring fiber interference on the collection efficiency are also discussed.
