Downloaded from https://www.everyspec.com MIL-STD-1311D PARTICLES INDICATOR 1. Purpose. This test is conducted to detect shorts caused by loose conducting particles within the tube envelope. 2. Apparatus. a. Short testing equipment with sensitivity as specified in method 1201. b. Accelerometer: Gulton model A-305, or equivalent. c. A device suitable for mounting and rotating the tube in the required positions. 3. Procedure. Subject each sample to one test cycle. a. Preheat at rated Ef and test with the heater energized. b. Throughout the following movements, tap 12 times (25 G, average blow, 300 µ s minimum time duration).
(1) With the tube vertical, rotate the major axis through a vertical plane to an inverted position and return. (2) Rotate the tube about its major axis for a minimum of 180 degrees and return (if not simultaneous with motion (1) above, the major axis shall be horizontal.) 4. Acceptance criteria. Any indication of a short during the test cycle shall be classified a major 2 defect. METHOD 1206 METHOD 1206 1206-1 19 April 1968