Downloaded from https://www.everyspec.com MIL-STD-81OC 10 March 1975 METHOD 502:1 LOW TEMPERATURE 1. PURPOSE. The low temperature test is conducted to determine the effects of low temperature on equipment during storage without protective packaging and service use. 1.1 General effects. Differential contraction of metal parts, loss of resiliency of packing and gaskets, and congealing of lubricants are a few of the clifficulties associated with low temperature. 2. APPARATUS. Temperature chamber. 3. PROCEDURES 3.1 Procedure I Step 1 - Prepare the test item in accordance with General Requirements, 3.2.
Step 2 - Lower the internal chamber temperature to the storage temperature -57° C (-70”F) or as specified in the equipment specificationand maintain for a period of 24 hours after stabilizationor for the period specified in the equipment specification. ) Step 3 - Inspect the test item in accordance with General Requirements, 3.2. Step 4 - Adjust the internal chamber temperature to the lowest temperature under which the test item is designed to operate as specified in the equipment specification and maintain until temperature stabi- , lization of the test item is reached.
Step 5 - Operate the test item until the item is stabilized or for the time specified in the equipment specification and obtain results in accordance with General Requirements, 3.2. Step 6 - Return the test item, nonoperating, to standard ambient conditions and stabilize. 502.1-1 METHOD 501.1 10 March 1975