Keep in Mind Series No#3

Keep in Mind Series No#3 Medium Image

How to Test HEPA Filter Integrity?

How to Test HEPA Filter Integrity?

☑ Measure the aerosol concentration upstream of the filters

☑This aerosol concentration should be used as the upstream 100 % reference for the photometer. Downstream measurements are then displayed as percentage penetration of upstream concentration

☑The probe should then be traversed at a scan rate not exceeding 5 cm/s

☑Using overlapping strokes (1 cm recommended)

☑The probe should be held at a distance of 3 cm or less from the downstream filter face or the frame structure

☑Scanning should be performed over the entire downstream face of each filter, the perimeter of each filter, the seal between the filter frame and the grid structure, including its joints

☑ Measurements of the aerosol upstream of the filters should be repeated at reasonable time intervals between and after scanning for leaks, to confirm the stability of the challenge aerosol concentration (should not vary more than ±15 %)

Nov 4, 2020