Downloaded from https://www.everyspec.com MIL-STD-81OD 19 July 1983 II-3 ~. The following procedure provides the basis for collecting the necessary information concerning the test item in a severe temperature-shock environment: Step 1. ‘With the test item in the chamber, adjust the chamber air temperature to the low-temperature extreme specified in the teet plan. Maintain this temperature for 1 hour or until the’test item has’been stabilized, whichever is longer. , ,. Step 2. Transfer the test item to the high-temperature environment (as speoified in the test plan) in no more than 5 minutes.
Chamber control shall be such that after insertion of the test item, the chamber temperature shall be .-: within the specified test tolerance after a period of not more than of the exposure time. Cycle t,hechamber through the appropriate diurnal cycle until I the test item reaponae temperature (from the test plan) haa been reached. Maintain this temperature until the teat item has stabilized. (See General Requirements, 4.4.3.) ~ ,. Step 3. Tranafer the test item to the low-temperature environment as above, and stabilize it at that temperature. I NOTE:
If the test procedure is interrupted becauee of work schedules, etc., the test item can be left at the test temperature or returned to standard ambient conditions for the time required. Before centinuirigthe teat, the test item must be restabilized at the temperature of the last successfully completed period before the interruption (see II-1.3). . . Step 4. Repeat steps 2 and 3. Step 5. Repeat step 4. Step 6. Return the test item to controlled ambient conditions (General Requirements, 4 .4b) and stabilize. Step 7. Operate and inspect the test item and obtain results-in accordance with General Requirements, 4.5.6. Compare these data with the pretest”data. 11-4 ~ a.
Previous test methods to which the test item has been subjected’. b. Results of each Performance check and visual comparison with the fail~re criteria. examination, and !’., .. (1) Pretest. (2) During test. ,* (3) Post-test. METHOD 503.2 19 July 1983 I 503.2-12