First of all, we need to check HEPA filter leakage. After finishing installation, do the leakage inspection for HEPA filter based on Clean Room Construction and Acceptance Criteria.
Next step is to test average air velocity on the nozzle mouth. It used method on GB 8070. Average airflow velocity inside air shower is arithmetic mean. Noise measurement should be done 1000 mm away from the center of horizontal side of air shower door. Also it’s measured 1500 mm above from ground.
Illumination test is done every 500 mm inside air shower. The measurement point should be set at least 150 mm away from inside door. We set illumination meter 800 mm high above ground to test various measurement points.
Install pressure gauge outside of air shower cabinet to test differential pressure. Place a tube inside air shower, 1 m high above the ground, 20 cm away from inner cabinet. Close the door and run the fan. Get differential pressure values after around 15 seconds.