Downloaded from https://www.everyspec.com MIL-:TD-810D 19 ,July 1983 ~ SOLAR’RADIATION (SUNSHINE) IaKQ SECTION I I-1 PURPOSE . : . . . . . . . . . . . . . . . . . . . ...505.2-1 I-2 ENVIRONMENTALEFFECTS . . . . . . . . . . . . . . . . . 505.2-1 I-3 GUIDELINES FOR DETERMINING TEST PROCEDURES AND TEST CONDITIONS . . . . . . . . . . . 505.2-2 I-4 SPECIAL CONSIDERATIONS . . . . . . . . . . . : . . - . 505.2-8 I-5 \ REFERENCES . :........ . . . . . . . . . . . . 505.2-8 ,.i SECTION 11 II-1 APPARATUS . . . . . . . . . . . . . . . . . . . . . . .505.2-10 II-2 PREPARATION FOR TEST . . . . . . . . . . . . . . . . . 505.2-13 II-3 PROCEDURES . . . . . . . . . . . . . . . . . . . . .
.505.2-14 II-4 INFORMATION TO BE RECORDED . . . . . . . . . . . . . . 505.2-1’7 SECTION I I-1 ~. This test ii conducted to determine the effects of solar radiation on equipment that may be exposed to sunshine during operation or unsheltered storage on the earth’s surface or in the lower atmosphere. I-2 ~ I-2.1 ~ effect&. The heating effects of solar radiation differ from those of high air temperature alone in that the amount of heat absorbed or reflected depends on the roughness and color of the surface on which the radiation is incident.
In addition to the differential expansion between dissimilar materials, ohanges in the intensity of solar radiation may oause components to expand.or contract at different rates, which can lead to severe stresses and loss of structural integrity. In addition to those speciFied in method 501.2, some other examples of heating effects include: a. Jamming or loosening of moving parts. b. Weakening of solder joints and glued parts. ,.. c. Change in strength and elasticity. d. Loss of calibration or malfunction of linkage devices. e. .2, Loss of seal integrity. f. Changee in electrical or electronic components. g. Premature actuation of electrical contacts. METHOD,505.2 19 July.1983. 505.2-1 -