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

APPENDIX A

A.4.1.1 Additional samples for extension of tolerances qualification. Where qualification to a lower

resistance tolerance is desired (such as .02 percent, .01 percent), ten additional sample units each of the

highest value and lowest or 10 ohms, whichever is higher, in the lowest resistance tolerances for which

qualification is sought, shall be submitted and subjected to the inspection of group I, IA of table IX.

A.4.2 Extent of qualification by product level. The extension of qualification between failure rate

levels shall be as specified in table A-III.

TABLE A-III. Extent of qualification by product level.

Product level

Will qualify product level

R, P, M

P, M

C (non-ER)

A.4.3 Extent of qualification by terminal. The extension of qualification between terminal types

shall be as specified in table A-IV.

TABLE A-IV. Extent of qualification by terminal.

Terminal symbol

Will qualify symbol

U (with 60 additional U

submitted, see A.3.2)

L (with 70 additional L

submitted, see A.3.2)

A.5 SOLDER DIP (RETINNING) LEADS

A.5.1 Solder dip (retinning) leads. The manufacturer (or their authorized category B or category

C distributor) may solder dip/retin the leads of product supplied to this specification provided the

solder dip process (see A.5.2 of this appendix) or an equivalent process has been approved by the

qualifying activity.