Downloaded from https://www.everyspec.com MIL-STD-1311D GLASS ENVELOPE STRAIN 1. Purpose. To check for strains which may cause breakage under severe temperature extremes. 2. Test equipment. Two water containers are required. One shall contain boiling water (97 ° C minimum) and the other shall contain water at melting ice temperature (5 ° C maximum). The volume of water shall be large enough to be appreciably unaffected in temperature by the test. 3. Procedure. The glass bulb, but not the base, of the tube shall be immersed in the hot container for a minimum period of 15 seconds and thereafter immediately immersed in the cold container for a minimum period of 5 seconds.
For all glass type tubes, the entire tube shall be immersed. 4. Acceptance criteria. a. The glass envelope shall not crack or break. b. Electrical rejects may be used for this test. METHOD 1126 METHOD 1126 1126-1 19 April 1968