Downloaded from https://www.everyspec.com MIL-STD-81OD 19 Jllly1983 MRTHOD 500.2 LOW PRESSURE (ALTITUDE) ,. .’,. SECTION II II-1 UEAWXLS - 11-1.1 E@ famhki. . . The required apparatus consists of a chamber or,,cabinet and auxiliary instrumentation capable of maintaining monitoring the specific conditions of low pressure. and centinuously For procedure 111, the in the prescribed time facility shall be capable of providing decompression period. 11-1.2 Cm trek a. 10 mls Unless otherwise specified, the.altitude change rate shall not “exceed 2,000 ft/min). b. Continuous recordings of chamber pressure shall be taken if require’d.
Readout charts should be capable of being read with a resolution within 2 percent of full scale. c. 11-1.3 Ii@ interruotion. (See General Requirements, b.5 .Q.) TO achieve the desired effects, the test item must be subjected to the low-pressure (altitude) environment without interruption. a. uLl rruutio . Any occurrence that causes the teat section preseure to deviate more than 10 percent of the measured value (in meters or feet) toward ambient atmospheric conditions shall be followed by a repeat of the entire test. b.
Qva’test interruDti.om Any occurrence that results in a pressure decrease of more than 10 percent Df the measured value below that cited by the requirements document should be followed by a complete physical examination and operational check (where possible). Any evidence of deterlOratiDn should result in a retest. Reinitiation of the entire test with a new test item is allowed. If no deterioration is detected, the entire test shall be repeated. c. II-2.1 lreli inarv stew. m Before initiating any testing, determine from the test plan: a. Which test procedures are required. , b. The low-pressure operation and storage requirements. II-2.2 fretes t standa rd ambient checlw ut.
All items require a pretest checkout at standard ambient conditions to provide baseline data. Conduct the checkout as follows: \ ,MSTHOD 500.2. 1,{July 1983 \ 500.2-6 \,