Downloaded from https://www.everyspec.com MIL-STD-810D 19 ~uly 1983 mo’nthly, year round. The frequenty,decreases as the distance from the equator increases. The midlatitudes can experience these conditions several days a month for 2 to”3 months a year. (3) Cyclic high huEL&.& . . Cyclic-high-humidity conditions are found in the open in tropical areas where solar radiation is.a factor. In these areas, exposed items are subject to alternate wetting and drying, but the frequency and duration of occurrence are essentially the same as in the constant-high-humidity areas. In addition to these three categories of natural high-humidity,conditions, there are two cycles for,induced conditions:
(4) hot -.. ed This condition exists when equipment in the category receives heat from solar radiation with little or.no cooling hot-humid air. equipment radiation (5) Induced var~. This condition exists when in the variable-high-humiditycategory receives heat from solar with little or no cooling air. ~. The number of temperature-humidity cycles (total test time) is critical in achieving the purpose of the test. It is preferable to use the number of cycles given in the requirements documents for the materiel. If this information is not available, use the following guidance (ace table 507,2-11): b. 0 NOTE:
“Anydegradation that could contribute to failure of the test item during more extensive exposure peri”odsor during exposure to other deployment environments, such ae’shock and vibration, shall be documented. Further”, testing shall be extended for a sufficient period of time to evaluate the long-term effect of its realistic deployment duration (deterioration rate becomes asymptotic). (1) Dt’OCeduW I Nat@ (a) ~. Hazardous test items are those in which any unknown physical deterioration sustained during testing could ultimately result in damage to materiel or injury or death to personnel when the test item is used.
Hazardous test items will generally require longer test durations than nonhazardous teet items to establish confidence in the test results. Twice the normal test duration is recommended (see table 507.2-II, cycles 1 through”3). Each test can be terminated prematurely after the quick-look level hag been reached if the materiel has failed the visual or func,tional checkout. . (b) ~ teat i terns. N“onhazardotistest items should be exposed from 10 to 60 cycles of conditioning, depending upon the geographical area to which the materiel will be expoaed (see table 507.2-II, cycles 1 through 3).
Each test can be terminated prematurely after the quick-lock level has been reached if it is determined that the test item has alrsady failsd the test and furthsr testing is futile. I &THOD ,507.2 1? July 1983 507.2-8