Labconco Purifie Horizontal Clean Benches 3970424 - Manual (Page 33)

Chapter 6: Maintaining Your Vertical Clean Bench
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HEPA Filter Leak Test
Purpose
After installing the new HEPA filter, the HEPA filter should be leak checked.
This test is performed to determine the integrity of the HEPA filter, the filter
housing, and the filter seal. Leak testing must be done by a qualified technician
with calibrated equipment. Remove the upper perforated diffuser located inside
the enclosure by using a Phillips screwdriver to unfasten the screws. (See Figure
6-1). The filter passes the leak test at .01% or better. Reference Leak Testing and
Photometer scanning from the Institute of Environmental Services (IES-RP-
CC001.3)
Apparatus
1. An aerosol photometer ATI model 2D, 2E, 2G or equivalent. Air
Techniques Hamilton Associates Inc., 11403 Cron Ridge Dr., Owings Mills,
MD 21117
2. One aerosol generator of the Laskin nozzle(s) type. An aerosol of mineral
oil or suitable liquid shall be created by flowing air through it. The compressed
air supplied to the generator should be adjusted to a pressure of 10± 1 psig.
during operation. Air Techniques Inc. Model TDA-4A or equal. One nozzle at
10 psig is (67.5 cfm x 100ug/l)/(Vol. of air), For the 2' at 55 fpm or 230 cfm,
one nozzle @10 psig is 6750/230 cfm = 30 ug/l. For the 3' at 55 fpm or 340
cfm, one nozzle @ 10 psig is 20 ug/l. For the 4' at 55 fpm or 460 cfm, one
nozzle at 10 psig is 15 ug/l.
3. Mineral oil (Catalog #1491400).
4. Sampling Nozzle, Rectangular 1/2" x 3-1/4", Air Techniques, Inc.
Procedure
For the ATI 2G Photometer
1. Turn on the photometer and allow it to operate for a minimum of 5 minutes.
Leave the valve in the “CLEAR” setting.
2. Press the “ENTER” keypad. Press the “REF” keypad.
3. The display will display “P1” for approximately 1 second, and then display a
numerical value.
4. Using the “^” or “ν” keypads, respectively, increase or decrease the numerical
value until it equals 30 (2'), 20 (3'). 15 (4') for the Purifier Vertical Clean
Bench enclosure at 55 fpm downflow 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.
HEPA