Downloaded from https://www.everyspec.com MIL-STD-810D 19 July 1983 METHOD 502.2 LOW TEMPERATURE Easf SECTION I I-1 PURPOSE . . . . . . . . ...” . . . . . . . . . . . I-2 ENVIRONMENTAL EFFECTS . . . . . . . . . . . . . . . I-3 GUIDELINES FOR DETERMINING TEST 502.2-1 502.2-1 PROCEDURES AND TEST CONDITIONS . . . . . . . . . . I-4 SPECIAL CONSIDERATIONS . . I-5 REFERENCES 502.2:2 502.2-’/ 502.2-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SECTION II II-1 APPARATUS . II-2 PREPARATION II-3 PROCEDURES II-4 INFORMATION . . . . . . . . FOR TEST . . . . . . . . . . . TO BE RECORDED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
502.2-9 502.2-10 502.2-10 502.2-13 SECTION I I-1 ~. Low-temperature chamber tests are performed to determine if materiel Can be stored. manipulated. and oDerated under t)ertinentlow- temperature conditions’witho~t experiencing physical da~ge or deterioration in performance. 1-2 ~. Low temperatures have adverse effects On almost all basic materials. As a result, exposure of test items to low temperature may either temporarily or permanently impair the operation of the test item by changing the physical properties of the material(s) composing it. Therefore, low-temperature tests must.be considered“wheneverthe test item will be expOsed to temperatures below standard ambient.
Examples of some problems that could occur as the result of expoaure to cold are: a. Hardening and embrittlement of materials. ... b. Binding of parts from differential contraction of dissimilar materiala . and the different rates of expaneion of different parts in response to temperature transients. c. Loaa of lubrication and lubricant flow due to increased viscosity. d. Changes in electronic components (resistora, capacitors, etc.). METHOD 502.2 502.2-1 19 July 1983