MIL-PRF-22E
e. Measurements prior to rotation: Total resistance (see 4.7.3 to 4.7.3.1.2, as applicable) shall be measured.
f. Measurement during rotation: Resistors shall be monitored for evidence for intermittent contact between the
contact arm and the resistance element.
g. Measurement and examination after rotation: Total resistance (see 4.7.3 to 4.7.3.1.2, as applicable) shall be
measured and examined for evidence of mechanical damage.
4.7.12 Terminal strength (when applicable). Total resistance (see 4.7.3 to 4.7.3.1.2, as applicable) shall be
measured. A 20 pound tensile load, in a direction normal to the mounting plane of the resistor, shall be applied in
turn to each terminal for one minute. Total resistance (see 4.7.3 to 4.7.3.1.2, as applicable) shall be measured.
Resistors shall be examined for evidence of mechanical damage (see 3.15).
4.7.13 Shock (specified pulse). Resistors shall be tested in accordance with method 213 of MIL-STD-202
(see 3.16). The following details and exceptions shall apply:
a. Mounting method and accessories: Resistors shall be mounted by their normal mounting means on an
appropriate fixture. The mounting fixture shall be constructed in such a manner as to insure that the points
of theresistor mounting supports will remain in a static condition with reference to the shock table. Test
leads used during this test shall be no larger thatn AWG 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 equipment in such a manner that the stress applied is
in the direction which would be considered most detrimental. Locking bushing type resistors shall have the
locking nut tightened with a torque wrench not greater than 8 inch-pounds.
b. Measurements before shock: Total resistance (see 4.7.3 to 4.7.3.1.2, as applicable) shall be measured
between the contact arm terminal and one end terminal, with the contact arm positioned at the approximate
midpoint of the resistance element.
c. Acceleration: 50 gravity units (g s).
d. Number and direction of blows: Resistors shall be subjected to a total of 30 blows, as follows:
(1) Ten blows applied with the resistors in a horizontal plane and with the shafts extended upward.
(2) Ten blows after the fixture has been rotated 180 degrees so that the shafts extend downward.
(3) Ten blows after the fixture is rotated 90 degrees so that the resistors are in a vertical plane with the
removable contact arm in a horizontal position.
e. Measurement during shock: Each resistor shall be monitored to determine electrical discontinuity. A
measurement of transient resistance change between the contact arm terminal and left terminal shall also
be made.
f. Measurement and examination after shock: Total resistance (see 4.7.3 to 4.7.3.1.2, as applicable) shall be
measured and examined for evidence of mechanical damage.
4.7.14 Acceleration (when applicable) (see 3.17).
4.7.14.1 Mounting of resistors. As specified in 4.7.13a.
4.7.14.2 Procedure. Total resistance (see 4.7.3 to 4.7.3.1.2, as applicable) shall be measured between the contact
arm terminal and one end terminal. The resistors shall be subjected to a constant acceleration of 50 g s for a period
of five seconds in each of the positions specified in 4.7.13d.
15
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business