Tins Intel national Standard specifics tests to evaluate the effects of temperature variations on components or equip-ment used in an craft. The tests have limited application and should only be specified in the relevant equipment specifi-cation when the thermal effects due to a change of tem-perature are significant to the operation of the equipment. The tests will enable equipment manufacturers to demonstrate that then equipment — when exposed to changes of temperatuie — will continue to function, and/or
suivive.
Two categories of test are described :
1) Temperature variations generally applicable to equipment likely to be subjected to gradual changes in atmospheric temperature, and
2) Thermal shock - generally applicable to equipment likely to be subjected to rapid or instantaneous changes in atmosphenic temperature.
The tests are not suitable for equipment installed in locations wheie the heat transfer rate is greatly increased by high velocity ot tutbulent an movement (for example external to the aircraft or in intake or supercharger ducting), where the temperatuie change affects only certain paits or surfaces of the equipment (for example radomes, windscreens, etc.), nor are they applicable to equipment which is subject to thermal shock by contact with a hot fluid (for example hydraulic components). For such equip-ment the lelevant equipment specification shall detail the appiopriate test to be conducted.