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|  MIL-C-21679(NOrd)
start. This force shall be applied to the stop lever in a.
direction perpendicular to the bottom plate of the clock
and along the center line of the clock.
4.6.3.4.2 Stop lever movement. - The plunger assembly
shall unlock the verge assembly when the stop lever is de-
pressed so that the distance between the bottom plate of the
mechanism and the outer side of the stop lever, measured at
the center of the mechanism, is not less than 0.090 inch.
When the stop lever is released to a position not more than
0.200 inch from the bottom plate, measured in the same manner,
the verge assembly shall be locked and the mechanism shall
have stopped.
4.6.3.5 Timing test. - The clock cable shall be con-
nected for test so that the individual leads coming from each
pair of clock switch contacts are connected to separate move-
ments of a graphic recorder, test item 4.4.1.1 (b). This
will permit the recording of the operating time of each switch.
The switches shall operate within the time limits specified
in 3.2.5.5. During this test, each sample mechanism shall be
allowed to run for 45 minutes in each of the following posi-
tions:
(a) With the mechanism mounting studs vertically up.
(b) With the mechanism mounting studs vertically down.
(c) With the verge directly above the escape wheel.
(d) With the verge directly below the escape wheel.
4.7 Environmental tests. - Mechanisms subjected to the
environmental conditons given below shall be tested there-
after to determine compliance with all other requirements of
this specification.
4.7.1 Temperature. - From each sample of mechanisms
submitted for test, at least one mechanism shall be tested,
in the following manner, to determine compliance with the re-
quirements of 3.3.1. During this test the rate of temper-
ature change shall be not less than 36 F per hour. First,
place the mechanism in a cold temperature chamber and de-
crease the temperature to -80 F and hold at this temperature
for a period of 3 days. Then raise the temperature to +28 F
and hold at this temperature for a period of 12 hours. With
the mechanism still in the chamber at +28 F, the mechanism
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