MIL-PRF-39015 Resistors, Variable, Wirewound, \(Lead Screw Actuated\), Nonestablished Reliability, And Established Reliability, General Specification ForThis specification covers the general requirements for nonestablished reliability \(non-ER\) and established reliability \(ER\), lead screw actuated; wirewound variable resistors with a contact bearing uniformly over the surface of the entire resistive element, wound linearly, when positioned by a multiturn lead screw actuator. These resistors are capable of full load operation \(when the maximum resistance is engaged\), at a maximum temperature of 85OC and are capable for continuous operation, when properly derated, at maximum temperature of 150OC \(see 3.6\), with a resistance tolerance of ??5 percent. The ER resistors have life failure rate \(FR\) levels ranging from 1.0 percent to 0.001 percent per 1,000 hours \(see 1.2.1.4\). These FR levels are established at a 60 percent confidence level on the basis of life tests.

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MIL-PRF-39015E

APPENDIX A

PROCEDURE FOR QUALIFICATION INSPECTION

A.1. SCOPE

A.1.1 Scope. This appendix details the procedures for submission of samples for qualification

inspection of resistors covered by this specification. The procedure for extending qualification of the

required sample to other resistors covered by this specification is also outlined herein. This appendix is a

mandatory part of the specification. The information contained herein is intended for compliance only.

A.2. APPLICABLE DOCUMENTS

A.2.1 General. The documents listed in this section are specified in sections 3, 4, and 5 of this

specification. This section does not include documents cited in other sections of this specification or

recommended for additional information or as examples. While every effort has been made to ensure the

completeness of this list, document users are cautioned that they must meet all specified requirements

documents cited in sections 3, 4, and 5 of this specification, whether or not they are listed.

A.2.2 Government documents.

A.2.2.1 Specifications, standards, and handbooks. The following specifications, standards, and

handbooks form a part of this document to the extent specified herein. Unless otherwise specified, the

issues of these documents are those cited in the solicitation or contract.

DEPARTMENT OF DEFENSE STANDARDS

- Leads for Electronic Component Parts.

(Copies of these documents are available online at https://assist.daps.dla.mil/quicksearch/ or

https://assist.daps.dla.mil or from the Standard Document Order Desk, 700 Robbins Avenue, Building 4D,

Philadelphia PA 19111-5094.)

A.2.3 Order of precedence. In the event of a conflict between the text of this document, and the

references cited herein (except for associated specifications, specification sheets, or MS sheets); the text

of this document takes precedence. Nothing in this document, however, supersedes applicable laws and

regulations unless a specific exemption has been obtained.

A.3. SUBMISSION

A.3.1 Product levels. Qualification of the C (non-ER) level is predicted upon meeting the ER

qualification requirements for FR level M (see A.4.1) and the completion of the qualification lot through the

10,000 hour life test. The procedure for submitting samples to become qualified to the initial FR level M

is specified in A.3.2.

A.3.2 Sample. The sample size and test routine for each style is as indicated in table A-I. All samples

are enclosed and have a minimum wire diameter not less than specified (3.1). After qualification has

been granted, there will be no changes in material, design, or construction, without prior notification to the

qualifying activity.