Downloaded from https://www.everyspec.com MIL-STD-81OD 19 July 1983 (~) ~ . The test conditions should reflect the extreme anticipated storage conditions. b. item temo~. The information in I-3.2a is intended to describe the air temperatures to which equipment will be exposed during various types of operations. Determination of the actual equipment.temperatures will be based on time of expected exposure and type of exposure. Actual onboard aircraft equipment temperatures can be calculated during a thermodynamic analyais as in method 520, estimated based upon expected flight durations, or assumed to be In equilibrium with the surrounding’air conditions.
Actual response temperatures achieved when equipment is exposed to the climatic conditions of the various ground climatic categories could be obtained from the .. test results of high- and low-temperature exposure (methods 501.2, 502.2, and 505.2) for either the operational or storage configuration. The latter assumption must take into account the induced effects.of “solartiadiatio~during storage and transit in various climates. . c. ~. An item is likely to experience the highest heating during storage in the sun in the Hot Dry and Basic Hot cli- mates. Therefore, transitions from hot to cold will be conducted with the test item stabilized at ita high-storage temperature.
Transitions from cold to hot will be conducted with the high-temperature facility air temperature at the maximum storage ‘temperatureof the appropriate cycle. Immediate y following this transfer, the high-temperature facility will be cycled through the appropriate diurnal cycle (table 503.2-I) from the beginning of the hour at which the maximum air temperature is experienced‘until the test item response temperature is reached. Other teats, such as electronic “screening,may require even more extreme temperature. o d. ~. The objective of this test is to determine the effect of rapid temperature changes .onthe test item.
Therefore, the test item must be exposed to the temperature extremes for a duration equal to either the actual operation (i.e., actual flight time) ‘or to that requi,redto achieve temperature stabilization. e. ~. The configuration of the test item strongly affects teat results. Therefore, the anticipated configuration of the item during storage, shipment, or use should b,eused during the test.. As a minimum, the,,followingconfigurations should be considered: (1) In a shipping/storage container or transit case. (2) Protected or unprotected. (3) Deployed (realistically or with restraint?). (4) Modified with kits for epecial applications. .G (5) Packaged for airdrop. . ... .... ...
METHOD 503.2 19 July 1983 503.2-8