Backstreaming/Induction Leak Test - Labconco Nexus 533 0 Series User Manual

8. If the aerosol generator requires pressurized air, connect the air line. Turn on the
appropriate number of Laskin nozzles for the model under test based on Table D-1.
Verify each nozzle is working properly.
9. Verify the generator's air pressure is 20 ± 1 psig.
10. At this point, aerosol is being dispensed from the generator. Do not let the generator
operate in this configuration for an extended period. Allow the generator to operate
for at least 15 seconds.
11. Set the photometer sampling valve to "DOWNSTREAM". Verify proper vacuum at
the sampling nozzle of the photometer.
12. Scan the HEPA filter(s) by passing the sampling nozzle in slightly overlapping
strokes over the entire surface of the filter. The sampling nozzle must be no more
than 1 inch from the surface of the filter media. Scan at a traverse rate of not more
than 2 inches per second.
13. Scan the entire periphery of the HEPA filter(s), including the gaskets between the
filter frame and the clean bench structure.
Acceptance Criteria
Aerosol penetration shall not exceed 0.01%.
14. Reinstall the diffuser, pre-filter(s) and retainer bracket(s).

Backstreaming/Induction Leak Test

To verify air from the surrounding environment is not entering the work area, follow
these instructions:
The following tools are required:
•
Non-thermal smoke source
•
Particle counter pickup (for Induction Leak Test)
1. All equipment and materials used in the work area on a regular basis must be
present for test.
2. Verify the clean bench's blower(s) are on and have reached a stable level.
3. Using an airflow visualization tool (smoke stick or smoke generator) of choice, scan
the smoke outlet along the edges of the work area opening 2 inches back from the
clean bench. Visible smoke should not enter the work area. If it does, see Step 4.
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