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|  MIL-C-21679(NOrd)
shall be tested to determine compliance with 4.6.3.5. During
the timing test, pre-heat a hot temperature chamber to 120 F.
Remove the mechanism from the cold temperature chamber and
immediately place it in the pre-heated chamber. Now raise
0
the temperature of the chamber from 120 F to 160 F and hold
at this temperature for a period of 24 hours. Then decrease
the temperature to 90 F and hold at this temperature for a
period of 12 hours. With the mechanism still in the chamber
at 90 F, the mechanism shall be tested to determine com-
pliance with 4.6.3.5. When the timing test has been completed,
remove the mechanism from the chamber and permit it to re-
turn to room temperature. Failure of the switches to operate
within the time limits set forth in 3.2.5.5 shall be cause
for rejection of the mechanism.
4.7.2 Vibration. ready-non-operating.- Mount the mech-
anism rigidly to the vibration table. The vertical dis-
placement component of the vibration shall be simple harmonic
motion. The samples shall be mounted on the vibration table
so that equal quantities of devices experience vibration per-
pendicular to the plane of mounting and vibration parallel
to the plane of mounting. The units shall be vibrated
through a range of frequencies from 700 to 3000 cycles per
minute in 100 cycles per minute increments. The duration of
the vibration of each increment shall be one hour. The ampli-
tude of the vibration shall be in accordance with the follow-
ing schedule.
AMPLITUDE
FREQUENCY
(inches)
(cycles per minute)
700
to
1500
0.030
0.002
1600
to
2000
0.020
0.002
2100
to
2500
0.013
0.001
2600
to
3000
0.009
0.001
4.7.3 Shock. ready-non-operating. - The mechanism shall
be subjected to a continuous two-phase shock applied in any
direction with respect to the mechanism. The first (impact)
phase shall consist of a minimum change in velocity of 5 1/2
feet per second taking lace in not more than 0.4 millisecond.
During the second (drag) phase, the mechanism shall be
accelerated for a minimum time of 15 milliseconds in such a
manner that during this time the minimum average acceleration
is 90 gravity units. The peak acceleration shall be between
125 and 175 gravity units.
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