MIL-PRF-39002C
4.6.22.2 Rotation. Total resistance shall be measured as specified in 4.6.2.1. A dc potential equivalent to that
required to dissipate rated wattage across the entire resistive element of resistors having the same nominal total
resistance as those under test shall be applied as shown on figure 4. Resistors shafts shall then be continuously
cycled through not less than 98 percent of the total mechanical rotation, at a rate of 10 cycles ±2 cycles per minute
for not less than 4,000 cycles per day for a total of 25,000 cycles (100,000 cycles for units of 2 inches or over).
Locking bushing types shall be rotated for a total of 500 cycles. The contact arm shall oscillate over the end of the
element to which connection is made and proper contact of the contact-arm with the winding shall be maintained.
The total resistance of resistors shall be ascertained at the end of every 5,000 cycles for all resistors except the
locking bushing types and 500 cycles for the locking bushing type. Following the test, the independent linearity
tolerance shall be determined as specified in 4.6.8.
4.6.22.3 Conformance inspection. At the option of the supplier, the sample units may be rotated at a rate of 8
cycles to 30 cycles per minute.
4.6.23 Terminal strength (see 3.28). Resistors shall be tested in accordance with method 211 of MIL-STD-202.
The following details and exceptions shall apply:
a.
Test condition letter: A. Applied force: Two pounds applied gradually to each terminal one at a time, in a
direction parallel to the major axis of the terminal.
b.
Examination after test: Resistors shall be tested for electrical continuity and examined for evidence of
mechanical damage.
5. PACKAGING
5.1 Packaging. For acquisition purposes, the packaging requirements shall be as specified in the contract or order
(see 6.2). When packaging of materiel is to be performed by DoD or in-house contractor personnel, these personnel
need to contact the responsible packaging activity to ascertain packaging requirements. Packaging requirements are
maintained by the Inventory Control Point's packaging activity within the Military Service or Defense Agency, or within
the military services system commands. Packaging data retrieval is available from the managing Military Department's
or Defense Agency's automated packaging files, CD-ROM products, or by contacting the responsible packaging
activity.
6. NOTES
(This section contains information of a general or explanatory nature that may be helpful, but is not mandatory.)
6.1 Intended use. The resistors covered by this specification are military unique due to the fact that these devices
must be able to operate satisfactorily in military systems under the following demanding conditions: 20 G's of high
frequency vibration, 100 G's of shock (specified pulse), thermal shock (with no more than 1 percent deviation in initial
resistance), low temperature coefficient of resistance, and salt corrosion. In addition, these military requirements are
verified under a qualification system. Commercial components are not designed to withstand these military
environmental conditions.
6.2 Acquisition requirements. Acquisition documents must specify the following:
a.
Title, number, and date of this date of this specification, the applicable associated specification, and the
complete PIN.
b.
Unless otherwise specified (see 2.1), the versions of the individual documents referenced will be those in
effect on the date of release of the solicitation.
c.
Packaging requirements (see 5.1).
6.2.1 PIN. This specification requires a PIN that describes by a coded dash number (see 1.2.1 and 3.1).
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