Downloaded from https://www.everyspec.com MI,L-STD-810D .1983 METHOD 521.0 ICING/FREEZING RAIN ...” ,, SECTION 11 II-1 AUAEUUS ,,. : . 11-1.1 ~. s The required apparatus consists of a ctiamberor Cabinet with ~ auxiliar~”equ,ipmentwhich has the ability to establish and maintain the test condiiion’a“specified. The chamber must be equipped .S’Othat test conditions within ‘thechamber can be stabilized within a reasonable time,;after the teat ~. item is loaded. Water delivery equipment (nozzles and dr%iria)shall be arranged to preclude the collection of puddles in the chamber. The chamber y.
shalI be equipped with instrtimentatiion, capable of maintainirigand continuously monitoring the test conditions. (See.General Requir.ements,4.4.2.) b. The thickness of the ice and the temperature “duringequipment operation are the important parameter. The precise methods for depositing the ice on the equipment are not important. (See I-3.2d.) II-1.2 ,Beforeeach test, critical parameters shall be’verified~ A spray pattern wide enough to guarantee uniform impingement for all test wind velocities shall be assured. Suggested techniques for spray calibration (if specified or considered essential) can be found in reference I-5j.
Unle9s otherwise”apecified in the equipment specifications (or other documents), if any action other than test item operation (such as apening the chamber door)’ results in a significant change in the test item or chamber air temperature (more than 20C (3.60F), the test item will be restabilized at the required temperature before continuation. If the operational check is not completed within 15 minutes, reestablish the test item temperature,conditions before continuing. I XI-1.3 X.vt interruD aqn. t. (~e General Requirements, 4.5.4.) a. test int~.
Interruption of a freezing rain test is unlikely to generate any adverse effects and normally the test shall .be continued from the point of interruption once the test conditions have been reestablished. ,1 b. Qver est t interruDtioti. AiIyinterruption that results in more extreme exposure of the test item than required by the requirements document or equipment specification should be followed by a complete OPeratiOnal and ,.. physical check. If no problems are encountered, the test item ehall be restored to its pretest condition and the test reinitiated. ,6., II-2.’ ~ 11-2.1 preliminary stem. :,. Before initiating any testing: ., . . ... METHOD 521.0 19 July 1983. 521.0-6