HEPA
Filter Integrity Test procedure
D.O.P.
TEST
Keep
the instrument in the area.
Ensure
that the instrument used for DOP testing is calibrated and calibration is
valid.
Provide
Nitrogen / Compressed air to the DOP smoke generator.
Keep
the smoke generator in the supply air plenum.
Smoke
will travel through supply air and come out through HEPA Filter.
Check
the 100% concentration before filter.
Move
the sensing probe at not more than 10 feet per minute at a maximum of 1 inch
under the HEPA Filter complete area.
If
leakage is there, needle on dial will show the deflection, Tighten the filter
properly and again repeat above procedure.
If
the penetration of smoke is less than acceptable limit the filter passes DOP
test.
If
probe shows penetration more than the acceptable limit within area of filter,
then filter is leaking. So replace filter and repeat the above procedure.
Collect
the test certificates from the outside agency and check as per requirement.
Take
five reading with vane type Anemometer in a plane parallel to and 6 inch downstream
of the HEPA filter in feet per minute. (four corners and one centre).
Note
down the reading and calculate the average velocity.
If
the velocity is less than the acceptable limit, check and reset the damper.
Even after correction if the velocity is below the acceptable limit, the filter
is choked and replace the same.
Carry
out the above test on the new filter.
Carry
out the above qualification once in a year.
