Supply Hepa Filter Leak Test - Labconco Logic Vue User Manual

Supply HEPA Filter Leak Test

This section provides the test method and instructions to challenge the supply HEPA
filter in the enclosure.
1. Open the Front Hatch.
2. Remove the Supply Diffuser by removing the Phillips Screws securing the
Diffuser.
3. Using a ladder, remove the Pre-Filter atop the enclosure (far right end). This will
require a 5/16" wrench to remove several Screws on the two Pre-Filter Brackets.
4. Place the aerosol generator next to the supply blower (or if insufficient clearance
between the top of the enclosure and the ceiling, a 2 inch (50 mm) or greater
diameter tube can be used to deliver the aerosol to the supply blower; and the
generator can remain on the ladder. The generator's output must be directed
into the blower intake.
5. Ensure that the generator is level, and the oil level is within 1/8 inch (3 mm) of
the level line.
6. Turn on the photometer and allow it to operate for a minimum of 5 minutes.
Leave the valve in the "CLEAR" setting for this 5 minute period.
7. Set the upstream concentration on the photometer based on the model under
test. See Table D-1, find the "Theoretical Aerosol Conc. (ug/L)" under the
section Supply HEPA Filter Leak Test
on the enclosure. Use the values provided in Table D-1.
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 23 psi.
10. At this point, aerosol is being dispensed from the generator. Do not let the
generator operate in this configuration for an extended period.
11. Set the photometer sampling valve to "DOWNSTREAM". Verify proper vacuum
at the sampling nozzle of the photometer.
12. Scan the downstream side of the supply HEPA filter 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 supply HEPA filter, including the gasket between
the filter frame and the enclosure structure.
Note: When scanning the front edge of the supply HEPA filter, photometer operation
may become erratic due to the aspiration of room air into the front of the work area.
This problem can be minimized or eliminated by placing the edge of a sheet of rigid
plastic or metal just outside the edge of the HEPA filter when scanning the front edge.
See Figure 4-26 for reference.
Data. Upstream Sampling is not available
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