Downloaded from https://www.everyspec.com MIL-STD-81OD I 1 .t, (a) Mercury vapor lamps (internal :eflecto~ tYPe onlY).“” 19’Juljf1983 (b) Combination of incandescent spot lampa and.tubular-type o ~ mercury vapor lamps with external reflectors. - (c) Combination of incandescent,spot,lamps and mercury vapor I lampa with internal reflectors. ,. (d) Metal halide. (e) Mercury xenon arclamps with suitable reflectors. MultivaDor (clear or coated bulb) with suitable reflectors. (g) Tungste.nfilament lampa.. -4 -’.. This list is not technology. intended to exclude new lamps made available by advanced 11-1,.2 QoLcszh . .. a. ~.
Chamber air temperature shall be maintained in accordance with General Requirements, 4.4.la, and measured (with adequate shielding from radiated heat) at a point or points in a horizontal plane O 50 mm below’the prescribed irradiation plane, at half the ‘distancebetween test item and the wall of the chamber or ‘at Im from.the test item, whichever is smaller. This ia to insure reasonable control of the envelope of air surrounding the test item. to the b. Dust and other surf’acecontaminantion may aignifi.cantlychange the absorption characteristics of irradiated surfaces. Unless otherwise required, apecimena should be clean when’they are tested.
However, if effecta of surface contamination are to be asseased, the relevant apecification should ,include the necessary information on preparation of sur- facea. c. nEl!l NLEMiwE Pyranometer or pyrheliometer” Total irradiation (“directaid scattered). I v Spectroradiometer or filtered fig of reading. ~ pyranometer ... I to .@~ W/m2 (*14 Btu/ft2/h)~ NOTE: ‘Valuea ma; be aashmed to represent plus or minus two.sthnd?rd -.. deviations; thus, the stated tolerances should not be e~ded in more than 1 measurement out of 20.
Solar radiation intensity shall be meaaured with a pyranometer or pyrheliometer’..Spectraljdistribution Of irradiance as a function of wavelength shall be meaeured with a spectraL radiometer or filtered pyranometer. . . . 0 METHOD 505.2~~ 19 July.1983 505.2-12 I