MIL-PRF-24236D
4.6.16 Vibration (see 3.21). Switches shall be tested in accordance with the applicable test methods of
MIL-STD-202, as follows:
(a) Method and test condition:
(1) For switches of classes 1 and 2 - Method 201.
(2) For switches of class 3 - Method 204 (vibration, high frequency), test condition - A.
(3) For switches of classes 4 and 6 - Method 204, test condition - D.
(4) For switches of class 5 - Method 204, 10 to 3,000 Hz, 50g.
(b) Tests and measurements prior to vibration - Not applicable.
(c) Mounting - The switches shall be rigidly mounted by their normal mounting means on a rigid metal
panel. The mounting fixture shall be free from resonances over the test frequency range.
(d) Electrical load conditions - The switches shall be functioning with voltage and current specified
specified, the test voltage shall be 28 volts dc.
(e) Tests and measurements during vibration:
(1) Resonance search - With the switch exposed to a temperature 5°F minimum above the operate point,
sweep slowly through frequency range and monitor for contact closure of more than 10 microseconds
by use of an oscilloscope or recording oscillograph, which has a frequency response of at least 5,000
Hz, or method 310 of MIL-STD-202. Repeat with unit exposed to temperature 5°F minimum below the
operate point.
(2) Vibration endurance - With vibration frequency set to the critical resonant point or cycling frequency, if
there is no resonance, and amplitude specified for the corresponding frequency, cycle switch
temperature through the operating point at a rate not exceeding 5 degrees F per minute, with
extremes not exceeding +10 degrees F around the operate point. Contact transfers within 3 degrees
F of the operate point will be disregarded and the cycling rate shall be a minimum of 5 cycles per hour.
4.6.17 Shock (see 3.22). Switches shall be tested in accordance with 4.6.17.1 or 4.6.17.2 as applicable (see 3.1
and 6.2.2).
4.6.17.1 Method I (shock, specified pulse) (applicable to classes 1, 3, 4, 5, and 6). Switches shall be tested in
accordance with method 213 of MIL-STD-202. The following details and exceptions shall apply:
(a)
Mounting method and accessories - Switches shall be mounted on a rigid metal panel by their normal
mounting means.
(b)
Test condition - H for classes 1 and 3; I for classes 4 and 6; D for class 5.
(c)
Electrical-load and thermal conditions - Half of the units shall be tested with the contacts closed while the
other half shall be tested with the contacts open. The electrical load shall consist of the monitor circuit only.
Measurements during shock - Switch-contact stability shall be continuously monitored by means of method
(d)
310 of MIL-STD-202.
(e)
Examination after test - Switches shall be examined for change in operation, and evidence of broken,
deformed, displaced, and loose parts.
4.6.17.2 Method II (high-impact shock) (applicable to class 2 only). Switches shall be tested in accordance with
method 207 of MIL-STD-202. The following details and exceptions shall apply:
Mounting fixtures - As specified in 4.6.17.1a.
(a)
Electrical-load conditions - As specified in 4.6.17.1c.
(b)
(c)
Measurements during shock - Switch-contact stability shall be monitored for each blow by means of method
310 of MIL-STD-202. In the event of indication of contact opening greater than 5 milliseconds, the test shall
be modified by applying successive identical blows in the same plane to monitor contacts, switch by switch,
to determine if a switch is defective.
(d)
Measurements after shock - Not applicable.
(e)
Examinations after test - Switches shall be examined for change in operation, and evidence of broken,
deformed, displaced, and loose parts.
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