Edition 3 April 2012 Mars/Mars Pro Service Manual
Page 47/59
Acceptance:
Air velocity in inlet = 0,40 ±10% m/s, = 345 m
3
/h.
The fan speed settings are to be recorded.
Alarms:
The alarm for inflow velocity is set to 0,4 m/sec = 310 m
3
/h, and the matching alarm level setting is recorded.
Alternatively:
Inflow speed measurement with a calibrated thermo-anemometer
Procedure: Take Window opening to 5 cm. Measure the air flow speed in 4 points. The flow speed should be
4 x 0.4 m/s = 1.6 m/s to be accepted
10.3 Airflow patterns, visualization
The purpose of the test is to verify that no smoke escapes from the working space to the room, and that smoke will be drawn
into the working space from the room.
Equipment:
Smoke stick, i.e. Dräger, Air Current Tube
Procedure:
Move the smoke stick in an steady movement along the front opening outside the cabinet. The smoke
must be drawn into the cabinet without visible turbulence.
Test the laminarity of the downflow and along the side-and back wall. No smoke must come out in the
room and only small turbulence must be observed.
10.4 Test of filters
Equipment:
Aerosol generator capable of producing test aerosol for HEPA filter leak testing.
Aerosol photometer with an upper measuring threshold of 10 µg/l to 100 µg/l and a range covering not
less than 5 log rates.
Test aerosol: PAO-4 from ATI, or
Emmery 3004 from Henkel Company, or an equivalent material.
Procedure:
Main-and exhaust filter:
Turn on the MSC and introduce the aerosol directly under the table top at the center of the cabinet.
Adjust the Photometer to 100% up-stream concentration
Scan the downstream side of the filter over the entire surface. Scan all filter joints and sealant for leaks.
Acceptance:
Maximum local penetration: 0.01% of upstream concentration.
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