MIL-PRF-22684F
4.6.12 Life (see 3.17). Resistors shall be tested in accordance with method 108 of MIL-STD-202. The following
details and exceptions shall apply:
a. Method of mounting: Resistors shall be mounted and soldered to lightweight terminals. The effective length
of each lead shall be 1 inch. Resistors shall be arranged so that the temperature of any one resistor shall not
appreciably influence the temperature of any other resistor. There shall be no circulation of air over the
resistors other than that caused by the heat of the resistors.
b. Test temperature: +70°C +15°C, -5°C.
c. Initial measurements: Measurements may be made inside or outside the chamber.
(1) Inside chamber: When measurements are to be made inside the chamber, the dc resistance shall be
measured at a temperature of 70°C ±5°C after temperature stabilization and within 8 hours of exposure
of the resistors to this temperature. This initial measurement shall be used as the reference temperature
for all subsequent measurements under the same conditions.
(2) Outside chamber: When measurements are to be made outside the chamber, the measurement shall be
made after units have been stabilized at room temperature for at least 8 hours. This initial measurement
shall be used as the reference temperature for all subsequent measurements under the same conditions.
d. Operating conditions: Rated continuous working voltage (see 3.1) shall be applied intermittently, 1 hour 30
minutes "on" and 30 minutes "off", for 1,000 hours. Adequate precautions shall be taken to maintain constant
voltage on resistors.
e. Test condition letter: D.
f. Measurements during test: Measurements may be made inside or outside the chamber. DC resistance shall
be measured at the end of the 30 minute "off " periods, after 250 hours, +72 hours, -24 hours; 500 hours, +72
hours, -24 hours; and 1,000 hours, +72 hours, -24 hours have elapsed. Measurements shall be made as
near as possible to the specified time but may be adjusted so that measurements need not be made during
other than normal weekdays.
(1) Measurements outside of chamber: When measurements are made outside the chamber, resistors shall
be outside of the chamber for a minimum of 45 minutes and stabilized before measurement.
g. Examination after test: Resistors shall be examined for evidence of mechanical damage.
4.6.13 Shock (specified pulse) (see 3.18). Resistors shall be tested in accordance with method 213 of
MIL-STD-202. The following details and exceptions shall apply:
a. Special mounting means: Resistors shall be mounted on approximate jig fixtures with their bodies restrained
from movement and their leads supported at a distance of .25 inch from the resistor body. These fixtures
shall be constructed in a manner to insure that the points of the resistor-mounting supports will have the same
motion as the shock table. Test leads used during this test shall be no larger than AWG size 22 stranded
wire, so that the influence of the test lead on the resistor will be held to a minimum. The test-lead length shall
be no longer than necessary. In all cases, the resistors shall be mounted in relation to the test equipment in
such a manner that the stress applied is in the direction which would be considered most detrimental.
b. Measurements before shock: DC resistance shall be measured as specified in 4.6.2.
c. Test condition: I.
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