Leak detection method of clean bench

According to the clean bench industry standard JG/T292-2010, the clean bench is mainly through the method of scanning leak detection, which specifically refers to the detection of aerosol leakage due to the leakage holes on the filter material of high efficiency (or super high efficiency) air filter and its frame, the poor sealing of the contact part of the filter and the installation frame, the incorrect installation of the filter and other reasons.

The detection method is based on the ratio of downstream particle concentration to upstream particle concentration (percent) to assess whether it is a leak, when using atmospheric dust can be assessed by the number of downstream particles, the concentration should be ≤ 3 particles / L, with the DOP method leak detection penetration rate of ≤ 0.01%. The bench used for biological clean use should also test the concentration of settling bacteria, the concentration of ≤ 0.5cfu/(dish.0.5h).
 

Detection using atmospheric dust or polydisperse aerosol as a source of pollution, when the above indicators can not be met, it is appropriate to occur polydisperse aerosol (such as PSL, DEHS, DOP, etc.), with a laser particle counter or high efficiency air filter downstream side from the filter surface 20-30mm, along the entire surface, frame and frame joints and other places to scan, scanning rate of 20-30mm / s.