MIL-DTL-62337C(AT)
other imperfections posing physical danger to the operators, and that the assembly and
components and securely installed and fastened.
4.8.5 Operating environments requirements verification.
4.8.5.1 Vibration. To determine conformance to 3.7.1, the assembly shall be mounted on
vibrating equipment with the filter element inserted and scavenge exhaust attached (see figure 2).
The assembly shall vibrate for a period of 80 min. at an amplitude of 0.9 gravity units and a
frequency rate from 5 to 500 to 5 Hz in each of the three mutually perpendicular axes as shown
in figure 1. The forced dwells as specified in figure 1 shall be performed in place of the
resonance search and dwells. Connections and instrumentation shall be attached to permit
testing as follows:
a. Test level shall be as specified in figure 3 when conducted at ambient temperatures.
The time schedule shall be a total of 80 min. per axis including the forced dwells as
specified figure 1.
b. The test item shall be vibrated along each axis in accordance with the condition
above. The frequency of applied vibration shall be swept over the specified range
logarithmically in accordance with figure 4. The specified sweep time is that of an
ascending plus a descending sweep and is twice the ascending sweep time shown in
figure 4 for the specified range. Linear sweep rates shall be substituted for the
logarithmic sweep rate. When linear sweep rates are used, the total frequency range
shall be divided into logarithmic frequency bands having similar time intervals such
that each time interval is the time of ascending plus a descending sweep for the
corresponding band. The sum of these time intervals shall equal the sweep time
specified for the applicable frequency range. The linear sweep rate for each band is
then determined by dividing each bandwidth in Hz by one half the sweep time in
minutes for each band. The logarithmic frequency bands may be readily determined
from figure 4. The frequency bands and linear sweep rates shown in table V shall be
used for the 2 (or 5) to 500 Hz and 5 to 2000 Hz frequency ranges. For test frequency
ranges of 100 Hz or less, no correction of the linear sweep rate is required.
c. After vibration, the assembly shall be examined for structural damage and shall be
subjected to an air leakage test as specified in 4.8.2.5 and the dust efficiency test as
specified in 4.8.2.3. The filter element shall be cleaned as specified in 4.8.2.4 prior to
performing the dust efficiency test.
4.8.5.2 Salt fog. The assembly shall be subjected and inspected to the salt fog
requirements of MIL-STD-810 method 509.3 to verify conformance to 3.7.2. After salt fog
exposure, the assembly shall be subjected to the efficiency test of 4.8.2.3.
NOTE:
A test coupon or witness sample which represents the assembly may be
subjected to the salt fog testing and visually inspected in lieu of a full
assembly test with prior approval from the procuring activity.
14
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business