Solar Radiation (Sunshine)

This test determines the effects of direct solar radiation on components and material. The heating effects of solar radiation differ from those of high air temperature in that the amount of heat absorbed depends on the roughness and color of the surface on which the radiation is incident and the angle of incidence to the sun. Variations in the intensity of solar radiation over the surface of the component, may cause components to expand or contract at different rates, which can lead to severe stresses and loss of structural integrity. In addition, degradation due to photo-chemical changes can occur such as fading of color, deterioration of natural and synthetic elastomers and polymers. The test items that are subjected to solar radiation testing are those that are exposed to solar radiation during its life cycle, in the open, in warm climates.

Solar radiation testing is specified in the following:

MIL-STD-810, MIL-STD-2036, MIL-S-3928, MIL-E-5272, MIL-T-7743, MIL-F-13926, MIL-E-16400, MIL-F-18870, MIL-D-22706