MIL-DTL-48556B
4.4 Environmental.
4.4.1 Storage temperature. With fresh batteries installed and quadrant purged with
dry nitrogen per 3.6, the quadrant shall be placed in the test chamber and the temperature of
the chamber reduced gradually to -60 ± 5°F and shall remain at this temperature for a
minimum of 4 hours. At the completion of this 4 hour period, the quadrant shall be
removed from the environmental chamber and inspected for signs of physical failure or
damage. The quadrant shall be placed back in the environmental chamber and the
temperature shall then be gradually raised to +160 ± 5°F and the quadrant shall remain at
this temperature for a minimum of 4 hours. At the completion of this 4 hour period, the
quadrant shall be removed from the environmental chamber and inspected for signs of
physical failure or damage. The quadrant shall be placed back in the environmental
chamber and the temperature of the test chamber shall be gradually reduced to room
ambient temperature (+60°F to +90°F) at which time the quadrant shall be removed from
the test chamber. The quadrant shall then meet the requirements of 3.5 through 3.14
inclusive. See 6.6, Thermal shock.
4.4.2 Operating temperature. With fresh batteries installed and quadrant purged
with dry nitrogen per 3.6, the quadrant shall be placed in the environmental chamber and
the temperature of the chamber reduced gradually to -50 ± 5°F. The quadrant shall remain
at this temperature for a minimum of 4 hours. At the completion of this 4 hour period, and
while at -50 ± 5°F, the quadrant shall meet requirements of 3.8 through 3.14 inclusive.
Upon completion of this portion of the test, the quadrant shall then be placed back in the
environmental chamber and the temperature shall be raised gradually to +145 ± 5°F. The
quadrant shall remain at this temperature for a period of 4 hours. At the completion of this
4 hour period, and while at +145 ± 5°F the quadrant shall again meet requirements of 3.8
through 3.14 inclusive. Upon completion of this test, the quadrant shall be returned to the
environmental chamber and the temperature shall be gradually reduced to room ambient
temperature (+60°F to +90°F) at which time the quadrant shall be removed from the test
chamber and shall meet the requirements as specified in 3.5 through 3.14 inclusive. See
6.6, Thermal shock.
4.4.3 Shock. The quadrant shall be mounted utilizing the keyway and four
mounting bolts torqued to 25-30 foot-pounds; fixture 11747195 may be used to adapt the
quadrant to the shock test equipment. The quadrant shall be subjected to the shock
requirements in accordance with 3.4.3. Upon completion of this test, the quadrant shall be
removed from the shock test equipment and shall meet the requirements as specified in 3.5
through 3.14 inclusive.
4.4.4 Vibration "A". The quadrant shall be mounted utilizing the keyway and four
mounting bolts torqued to 25-30 foot-pounds; fixture 11747195 may be used to adapt the
quadrant to the vibration test equipment. The quadrant shall be subjected to the vibration
requirements in accordance with 3.4.4. Upon completion of this test, the quadrant shall be
removed from the vibration test equipment and shall meet the requirements as specified in
3.5 through 3.14 inclusive.
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