The total volume of fluid in the test system shall remain
constant. Collect a sample of the contaminant injection fluid
at the point of injection.
Record particle counts on the auto-
Start test recording timer.
matic counter every 2 minutes. The counting time periods of
the two sensors shall be synchronized.
across the test filter shall also be recorded at the same time
At 80 percent of specified terminal differential pressure open
valve A. Extract a fluid sample of not less than 500 mL on the
upstream side of the test filter assembly.
differential, then when
If test is to be terminated at 30
pressure differential across test element reaches 30
ferential, stop timer, stop fluid sampling flow and stop injection
Continue recording differential
flow from the contaminant system.
pressure across the test filter element.
If collapse test is to be run as part of 4.7.5 then continue test
Particle counts are not necessary
for this test phase.
Collect another sample of the contaminant injection fluid at
the point of injection upon completion of test.
Analyze gravimetrically per SAE ARP 785 the two samples extracted
from the contaminant injection system (see 188.8.131.52 (d) and (i)).
Calculate the average of these two gravimetric levels. The
gravimetric level for each sample shall be within 10 percent
of this average for the test to be valid.
Analyze gravimetrically the fluid sample extracted from the
upstream side of the test filter assembly and report in
accordance with SAE ARP 785 (see 184.108.40.206 (f)).
Filter efficiencies shall be reported for 3 and 5 micrometers
particle sizes as filtration ratios
defined in 220.127.116.11.
4.7.5 Collapse test.
The collapse test procedure shall be as follows.
Run filtration ratio test for element no. 3 according to
18.104.22.168 (a) through (f).
differential turn off counters, continue to inject
contaminant, and increase flow to 70 gal/min.
Maintain increased flow rate until 180
pressure is reached.
Stop contaminant injection. Reduce flow to 10 gal/min
in test circuit clean-up filter.
Continue testing with 10 gal/rein flow, conforming to 22.214.171.124 (c)
through (g). Present filtration ratios (see 4.7.4) on particle
counts obtained in 126.96.36.199 (c) through (g).
Plot pressure drop versus cumulative weight contaminant added
and include in test report.