MIL-F-24 666 (SH)
184.108.40.206 Filtration ratio.
The filtration ratio
is defined as the
in the influent
ratio of the number of particles greater than a given size
in the effluent
fluid to the number of particles greater than the same size
From the automatic particle counting data, values of filtration ratio
The time averaged filtration
are calculated at each counting time interval.
for each of the given size ranges shall be averaged for the portion
across the test element,
of test run at rated flow up to 30
shall be plotted on log normal graph paper, with
plotted on the log-scale
on the normal-scale.
and the micrometer size range
The average filtration
ratios for any given particle size shall not be lower than the values specified
220.127.116.11 Test system. A typical test circuit is shown on figure 4.
Reservoirs shall be constructed with a smooth conical bottom that has an included
angle of not more than 90 degrees. The oil entering the reservoir shall be
diffused below the surfaces of oil in the reservoir. The lines shall be sized
such that turbulent flow exists throughout the system. Fluid aeration shall
be held to a minimum.
An anti-static additive, such as ASA3 shall be used to
dissipate static electric charges.
Not more than 50 p/m shall be used
18.104.22.168 Element test circuit. Conditions stated herein shall apply to
test circuit validation and to element testing.
(a) The clean-up filter assembly filter (1) shall clean the element
test circuit to the extent that particles greater than 3 micro-
meters in size do not exceed 500 particles per 100 milliliters
(mL) of test fluid.
(b) The total fluid volume of the element test circuit shall be
equal to or less than that volume which would flow in 1 minute
at rated flow plus or minus 2 percent.
per minute (L/min) multiplied by 1 minute equals 48 plus or
minus 1 liter). This volume may be attained by adjusting the
reservoir fluid level.
(c) The test stand shall be capable of supplying fluid to the test
element at element rated flow.
(d) Turbulent sampling means in accordance with ANSI B93.19 shall be
located upstream and downstream of the test element and shall be
Flow to the
connected directly to the automatic particle counter
automatic particle counter shall be high enough to minimize lag
time. The portion of the sampling flow not passing through the
counter shall be returned to the element test circuit via the by-
Sample flow shall not be interrupted during the test.
In no case shall the element test circuit volume vary by more
than 15 percent of the required volume during the test.
(e) pressure taps upstream and downstream of the housing shall be in
accordance with SAE ARP 24B.
22.214.171.124 Contaminant injection circuit. A typical circuit is shown on
figure 4. The cleanup filter assembly shall be capable of cleaning the contami-
nant inject ion circuit to the extent that particles greater than 10 micrometer
in size do not exceed 250 per mL, and are less than 2 percent of the gravimetric
values of injection circuit fluid specified in 126.96.36.199. The total fluid volume
of the injection system circuit shall be sufficient to contain the fluid volume