Downloaded from https://www.everyspec.com MIL-STD-1311D METHOD 1047 (OPERATING) 1. Purpose. The purpose of this test is to determine the performance of electron tubes at high or at low temperature. 2. Equipment. The test chamber shall be capable of maintaining the specified ambient temperature. Facilities shall be available to measure performance of the tubes. 3. Procedure. 3.1 High-temperature operation. The tube shall be introduced into the test chamber and the chamber temperature then adjusted to 100 ° C. The tube shall be maintained in this environment for sufficient time to reach equilibrium, but for not less than 5 minutes before the application of voltages.
After reaching equilibrium and following the specified warm-up, the tube's performance shall be measured under the conditions specified. 3.2 Low-temperature operation. The tube shall be introduced into the test chamber and the chamber temperature then adjusted to -55 ° C. The tube shall be maintained in this environment for sufficient time to reach equilibrium, but for not less than 5 minutes before the application of voltages. After reaching equilibrium and following the specified warm-up, the tube's performance shall be measured under the conditions specified. HIGH- AND LOW-TEMPERATURE PERFORMANCE METHOD 1047 1047-1 19 April 1968