Downloaded from https://www.everyspec.com MIL-STD-81OC 4.2 Precedure 3.I; heat flux simui-ation. The test object shall be located within the test chamber (Apparatus2.1) having a cryogenic heat sink (Apparatus 2.3). A heat flux simulation source (Apparatus2.2.2) shal1 be provided surrounding the test object and thermally isolated from,it. The test object shall be supported by low heat conduction means. The test shal1 be performed as described in 4.1.1. 4.3 Procedure II1, heat-flux simulation with thermal canister. The test object shal1 be located within the test chamber (Apparatus2.1) having a cryogenic heat sink (Apparatus2.3) with a thermal canister.
The test object shall be mounted within the canister by low heat conduction means. The test shal1 be performed as described in 4.1.1. 4.4 Procedure IV, heat flux simulation variable temperature shroud. The test object shall be located within the test chamber (Apparatus2.1) having a variable temperature shroud. The test object shall be mounted within the shroud by low heat”conduction means. The test shall be performed as de- scribed in 4.1.1. 4.5 Procedure V, heat flux with conductive source and cryogenic shroud. The test object shall be located within the test chamber [Auuaratus2.1) having a cr~ogenic heat sink (Apparatus 2.3). -..
The test object shal1 have a conductive source attached to it and shal1 be supported by low beat conduction means. 4.6 Procedure VI, vacuum-simulation. The test object shall be located within the test chamber (Apparatus2.1). Its volume should be preferably much smaller than chamber volume. All test fixtures should be vacuum compatible. 4.7 Procedure VI1, heat flux simulation with vehicie h6.aters. The test object shal1 be located within the test chamber (Apparatus 2.1) having a cryogenic heat sink (Apparatus 2.3). The test object shall have vehicle heaters (heaterblankets or fluid system) attacked to its surface. 5. DEFINITIONS.
Terms frequentlyused in solar simulation in conjunction with thermal vacuum testing are as follows: a. Absorptance. Absorptance is the ratio of the absorbed radiant flux to the incident radiant flux. Total absorptance refers to absorptance measured over al1 wavelengths. Spectral absorptance refers to absorptance measured at a specified wavelength. 517.2-10 MSTHOD 517.2 I