1.1 Purpose
Use the temperature shock test to determine if materiel can withstand sudden changes in the temperature of the surrounding atmosphere without experiencing physical damage or deterioration in performance. For the purpose of this document, "sudden changes" is defined as "an air temperature change greater than 10°C (18°F) within one minute".
1.2 Application
1.2.1 Normal Environment
Use this Method when the requirements documents specify the materiel is likely to be deployed where it may experience sudden changes of air temperature. This Method is intended to evaluate the effects of sudden temperature changes of the outer surfaces of materiel, items mounted on the outer surfaces, or internal items situated near the external surfaces. This Method, essentially, focuses on test item surface-levels. Typically, this addresses:
- a. The transfer of materiel between climate-controlled environment areas and extreme external ambient conditions or vice versa, e.g., between an air conditioned enclosure and desert high temperatures, or from a heated enclosure in the cold regions to outside cold temperatures.
- b. Ascent from a high temperature ground environment to high altitude via a high performance vehicle (hot to cold only).
- c. Air delivery/air drop at high altitude/low temperature from aircraft enclosures when only the external material (packaging or materiel surface) is to be tested.
1.2.2 Safety and Screening
Except as noted in paragraph 1.3, use this Method to reveal safety problems and potential flaws in materiel normally exposed to less extreme rates of temperature change (as long as the test conditions do not exceed the design limitations of the materiel).
1.3 Limitations
This method does not specifically address the following, but it may, in some cases, be applied through tailoring:
- a. Materiel that will not experience sudden extreme temperature changes to internal components because of its mass, configuration, packaging, installed location, etc.
- b. Replacement of the assessment of performance characteristics after lengthy exposure to extreme temperatures, such as with Methods 501.7 and 502.7.
- c. Temperature shock experienced by materiel transferred between air and liquid or two liquids, the thermal shock caused by rapid transient warmup by engine compressor bleed air, or aerodynamic loading.
- d. The actual transfer time in a service environment will not produce a significant thermal shock.
- e. Materiel that has been exposed to heat from a fire and subsequently cooled with water.
- f. Thermal shock testing that may be considered for safety or hazard assessment of munitions.
MIL-STD-810H
METHOD 503.7