Downloaded from https://www.everyspec.com MIL-STD-81OC Step 4 - With the test item de-energized, adjust the chamber test conditions to those specified in step 4 of table 504.1-11. After the test item temperature has stabilized, the chamber door shall be opened and frost permitted to form on the test item (see note (e)) The door shall remain open long enough for the frost to melt, but not long enough for the moisture to evaporate. The chamber door shal1 be closed and the test item operated at the highest specified input voltage (see note (d)) to ascertain satis- factory operation immediately following the specified warmup time.
The test item shall be energized and de- energized at least three times. Step 5 - Adjust the chamber test conditions to standard ambient conditions. After the test item temperature has stabi- lized; an operational and performance check of the test item”shill be made and the results compared with the data obtained in General Requirements, 3.2.1, and evaluated using the failure criteria of General Requirements, 3.2.4. Step 6 - With the test item de-energized, adjust the chamber test conditions to those specified in step 6 of table 504.l-II. The test item temperature shall be stabilized and then maintained for at least the length of time specified in step 6 of table 504.1-11.
At the conclusion of this time period, where practicable, the test item shall be visually inspected for any deteriorate ion. Step 7 - With the test item de-energized, adjust the chamber test conditions to those specified in step 7 of table 504.l-II. After the test item temperature has stabilized and while maintaining,thechamber temperature, operate the test item continuously at the highest specified input voltage (see note (d)) for the length of time specified in step 7 of table 504.1-11. Thermal sensor readings of the test item temperature shall be recorded every 30 minutes.
At the end of the time period specified in step 7 of table 504.l-II, and while maintaining the test conditions, t~e test item shall be checked for satisfactory operation and the results recorded. METHOD 504.1 504.1-4