MIL-STD-202H.pdf - 第126页

MI L - S TD - 202 - 20 6 CO NT E N T S PARAGRAPH PAG E FOREW ORD … ………………………………………………………. ii 1. SCOPE 1 1.1 Purpose …… ………………… …………………. …… .. …………. 1 2. APPLICABLE D O C U M EN T S 1 3. DEFINTIONS 1 4. GENERAL RE Q UI R …

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MIL-STD-202-206
FOREWORD
1. This standard is approved for use by all Departments and Agencies of the Department of Defense.
2. This entire standard has been revised. This revision has resulted in many changes to the format, but the most
significant one is the splitting the document into test methods. See MIL-STD-202 for the change summary.
3. Comments, suggestions, or questions on this document should be emailed to std202@dla.mil or addressed to:
Commander, Defense Logistics Agency, DLA Land and Maritime, ATTN: VAT, P.O. Box 3990, Columbus, OH
43218–3990. Since contact information can change, you may want to verify the currency of this address
information using the ASSIST Online database at https://assist.dla.mil.
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MIL-STD-202-206
CONTENTS
PARAGRAPH PAGE
FOREWORD…………………………………………………………. ii
1. SCOPE 1
1.1 Purpose………………………………………….……..…………. 1
2. APPLICABLE DOCUMENTS 1
3. DEFINTIONS 1
4. GENERAL REQUIREMENTS 1
4.1 Mounting………………………………………….…...…………. 1
4.2. Test potential and load………………………..……..…………. 1
4.3 Cycle………………………………………………………………. 1
4.4 Cycle rate…………………………………………………………. 1
4.5 Number of cycles...………………………………………………. 1
4.6 Temperature and atmospheric pressure………………………. 2
5. DETAILED REQUIREMENTS 2
5.1 Measurements………………………………………………….... 2
5.2. Summary……………………………………………………….… 2
6. NOTES 3
6.1 Supersession data………………………………………………. 3
FIGURE PAGE
1. Suggested mounting fixture for rotational-life test…………………….… 2
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北测（上海）电子科技有限公司
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MIL-STD-202-206
METHOD 206
LIFE (ROTATIONAL)
1. SCOPE
1.1 Purpose. This test is performed for the purpose of determining the effects of subjecting electronic and
electrical parts, which are actuated by rotational motion, to a number of operations approximating the life of the part.
Total resistance, contact resistance, and dielectric strength are samples of measurements which may be made prior
to, during, or after test, and which would show the effects of rotational actuation. Measurements prior to and after
test are generally made for comparison purposes and would indicate the amount of change that results from this test.
Parts with sealed shafts and bushings might have the effectiveness of the seal disturbed by rotation; a sealing test
performed after this test would disclose this inadequacy. A switch-life test may be performed in conjunction with this
test method.
2. APPLICABLE DOCUMENTS
This section not applicable to this standard.
3. DEFINTIONS
This section not applicable to this standard.
4. GENERAL REQUIREMENTS
4.1 Mounting. Specimens shall be mounted in their normal operating position by the intended means. Normal
care shall be taken in the mounting procedure to prevent the binding of shafts during rotation. Figure 1 shows a
suggested means of preventing this condition, when applicable. Mechanisms such as slip clutches may be used to
prevent damage from the application of excessive torque to the specimens. When this test is conducted at an
elevated temperature (see 4.6), the spacing between a group of like specimens shall be as specified.
4.2 Test potential and load. The test potential and load applied to the specimens during rotation shall be as
specified.
4.3 Cycle. A cycle shall consist of a rotation of the shaft from one stop position to the other stop position (passing
through detent positions, if any), and return to the original position. For specimens not having stops, a cycle shall
consist of a rotation of the shaft 360° and return, unless otherwise specified. Specimens with adjustable stops shall
have the stops so placed as to permit maximum rotation. Specimens that are rotated by means other than a shaft
shall meet the requirements of this paragraph by rotation 360° and return, unless otherwise specified, or from stop to
stop.
4.4 Cycle rate. The cycle rate shall be expressed in cycles per minute (cpm), and shall be as specified.
4.5 Number of cycles. Specimens shall be subjected to one of the following test conditions, as specified:
Test condition Number of cycles Test condition Number of cycles
A -------------------- 500 H -------------------- 100,000
B -------------------- 2,000 J -------------------- 200,000
C -------------------- 5,000 K -------------------- 300,000
D -------------------- 10,000 L -------------------- 500,000
E -------------------- 15,000 M ------------------- 1,000,000
F -------------------- 25,000 N -------------------- 2,000,000
G ------------------- 50,000
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