Filter
Top Products
45
Chapter 6: Maintaining Your Filtered Enclosure
4. Using the “^” or “ν” keypads, respectively, increase or
decrease the numerical value until it equals 52 (2'), 34 (3'). 26
(4') for the enclosure at 90 fpm inflow velocity.
5. Press the “ENTER” Keypad. The photometer will scan for 15
seconds, and then the “0” keypad will flash. Press the “Enter”
keypad. The unit will scan for 5 seconds, the display will read
“0000,” and the unit will sound a confirming tone.
6. Set the valve to “DOWNSTREAM.” Place the palm of your
hand over the sampling port of the pistol. There should be a
strong vacuum at this port. If the vacuum is weak, contact Air
Techniques Hamilton Associates.
7. Turn the enclosure on and let it operate for a minimum of 5
minutes.
8. If necessary, adjust the speed control of the enclosure to
maintain the following airflows at 90 fpm; 2' (130cfm), 3' (200
cfm, 4' (265 cfm.)
9. Position the aerosol generator discharge in the intake of the
baffle inside the enclosure.
10. Start the aerosol generator (Pressure to be +/- 1 PSIG). Ensure
that one Laskin nozzle is in the “open” position.
11. Allow the generator to operate for a minimum of 15 seconds.
For all integral motorized impeller models, scan the
downstream exhaust side of the HEPA filter by passing the
sampling nozzle of the gun in slightly overlapping strokes over
the entire surface the filter, with the sampling port not more
than 1 inch from the surface of the filter media. Scan the entire
periphery of the filter and the gasket between the filter frame
and the enclosure frame. Scanning shall be done at a traverse
rate of not more than 2 inches per second.
NOTE: For the Purifier Enclosures ducted to the outside,
place the sampling nozzle in the center of the
remote blower exhaust.
Acceptance
Aerosol penetration shall not exceed 0.01 percent measured by the
photometer.