MIL-PRF-39005 Resistors, Fixed, Wirewound \(Accurate\), Nonestablished Reliability, Established Reliability, General Specification ForThis specification covers the general requirements for nonestablished reliability \(non-ER\), established reliability \(ER\), accurate, wire-wound, fixed resistors that have a maximum resistance tolerance of 1 percent and a high degree of stability with respect to time under specified environmental conditions. The resistors are capable for continuous full-load \(or voltage\) operation at any ambient temperature up to 125??C, and when derated, up to 145??C \(see 6.5\). They are not capable for application where the alternating current \(ac\) characteristics are of critical importance. ER resistors have life failure rates \(FR\) ranging from 1.0 percent to 0.001 percent per 1,000 hours \(see 1.2.1.5\). These FR are established at 60-percent confidence level on the basis of the life tests. The FR, identified by the appropriate symbol, is referred to operation at full rated voltage and temperature.

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MIL-PRF-39005G

3.29 Workmanship. Resistors shall be processed in such a manner as to be uniform in quality and free

from any defects that will affect life, serviceability, or appearance.

4. VERIFICATION

4.1 Classification of inspection. The inspection requirements specified herein are classified as follows:

a. Qualification inspection (see 4.4).

b. Verification of qualification (see 4.5).

c. Conformance inspection (see 4.6).

d. Periodic group C inspection (see 4.7).

4.2 Reliability and quality.

4.2.1 QPL system. The manufacturer shall establish and maintain a QPL system as described in 3.3.

Evidence of such compliance is a prerequisite for qualification and retention of qualification.

4.2.2 SPC. A SPC program shall be maintained in accordance with EIA-557. Evidence of such

compliance shall be verified by the qualifying activity of this specification as prerequisite for qualification

and continued qualification.

4.3 Inspection conditions and precautions.

4.3.1 Inspection conditions. Unless otherwise specified herein, all inspections shall be performed in

accordance with the test conditions specified in the "GENERAL REQUIREMENTS" of MIL-STD-202.

4.3.2 Precautions. Adequate precautions shall be taken during inspection to prevent condensation of

moisture on resistors except during the moisture resistance temperature cycling tests. Precautions shall

also be taken to prevent damage by heat when soldering resistor leads to terminals.

4.4 Qualification inspection. Qualification inspection shall be performed at a laboratory acceptable to

the Government.

4.4.1 Sample. The number of sample units comprising a sample of resistors to be submitted for

qualification inspection shall be as specified in the appendix A to this specification. The sample shall be

taken at random from a production run and shall be produced with equipment and procedures normally

used in production. Each resistor style shall be qualified separately.

4.4.2 Test routine. Sample units shall be subjected to the qualification inspection specified in table IX,

in the order shown. All 324 sample units shall be subjected to the inspection of group I and group IA.

The 324 sample units shall then be divided as specified in table IX for group II through group VI inclusive

and group VIII, and subjected to the inspection for their particular group. An additional 10 to 20 sample

units, as applicable, and 19 additional sample units shall be subjected to the inspection of group IB and

group VII, respectively.

4.4.3 Defectives. Defectives in excess of those allowed in table IX shall be cause for refusal to grant

qualification.