MIL-DTL-38449D
4.4.3. The unit shall then be temperature cycled for a 24-cycle period, each cycle consisting of
the following:
a. The unit shall be placed in the chamber which has previously been stabilized at 130°C;
the unit shall remain in the chamber at 130°C for 15 minutes (unit non-operating).
b. The unit shall be removed from the chamber and allowed to remain at room
temperature for 15 minutes.
c. The functional test as specified in 4.4.3 shall be performed after 8, 16, and 24
temperature cycles.
4.4.7.2 Low temperature altitude. This test shall be conducted in accordance with MIL STD-
810, Method 502.1, procedure I, except that the chamber pressure shall be reduced to that
equivalent to 50,000 feet altitude during the last 21 hours of the test. The unit shall be
functionally test as specified in 4.4.3. An altitude at 100,000 feet shall be demonstrated or
adequately proven under non-operating conditions, the remaining 12 hours of the above 24 hour
test may be substituted by a 100,000 foot-altitude equivalent pressure and conducting the
functional test (4.4.3) upon returning pressure to sea level.
4.4.7.3 Fungus. The unit shall be tested in accordance with MIL-STD-810, Method 508.1. This
test may be omitted if the parts and materials of the unit contain no nutrients for fungus growth.
4.4.7.4 Salt fog. The unit shall be tested in accordance with MIL-STD-810, Method 509.1.
4.4.7.5 Humidity. The unit shall be tested in accordance with MIL-STD-810, Method 507.1,
procedure I.
4.4.7.6 Shock. The unit should be tested in accordance with MIL-STD-810, Method 516.2,
procedure I using a terminal-peak-sawtooth pulse configuration with a peak value of 20g for a
duration of 11 milliseconds. During the shock test, normally closed contacts shall be monitored
for momentary opening; an opening time of 0.5 milliseconds or greater shall constitute failure of
the unit.
4.4.7.7 Leakage (immersion). The unit shall be subjected to the leakage test in accordance with
MIL-STD-810, Method 512.1, procedure I.
4.4.7.8 Vibration. The vibration test shall be performed in accordance with MIL-STD-810,
Method 514.2, procedure I, curve D except that the 10g acceleration shall be extended to 1,000
Hz.
a. Each resonant and cycling period shall be divided into four equal parts; the first part
being conducted at -54°C, the second part at room temperature, the third part at 71°C, and the
fourth at -54°C (non-operating).
25
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business