Filter testing apparatus and method

摘要

A filter testing apparatus and method are provided wherein a challenge aerosol or the like is introduced upstream of the filter, and the downstream face of the filter is scanned with an air sampling probe to detect for the presence of leaking aerosol. The apparatus comprises a generally rectangular frame, and an air sampling probe which is mounted to the frame so as to be movable in a predetermined pattern wherein the entire face of an adjacent filter is scanned. The assembly may be removably mounted in a filter housing immediately downstream of the filter, or mounted on a framework downstream of a bank of several filters. In the latter instance, the assembly is sequentially indexed to a position alignment with each filter, and an upstream aerosol dispersion assembly is also provided which is correspondingly indexed across the filter bank. The rate of leaking challenge aerosol is continuously plotted on a moving sheet of paper to thereby permit the magnitude of a leak and its location on the face of the filter to be readily determined.