Downloaded from https://www.everyspec.com MIL-STD-810D 19 July 1983 , I-3.2 ~. After choosing the test procedure, choose the valuea of the test variables and decide whether or not the test item la to operate during the test. The specific test conditions .to,beused in these testa shouldrbe baaed.on field data (General.. Requirements, 4.3). If field data are not available, the teat conditions should preferably be selected from the applicable requirements.documents. If this information ia not available, the following may be used as guidance. ..! ,., a. ~.
Unless otherwise specified, these testa “shouldbe conducted at the operating or storage temperature obtained from the temperature response of the teat item from method 501.2. ,. ,. b. &!&j.yg humidif&..-High levels of relative humidity ay cauae :. -. caking of dust particles. Consequently, the test chamber RH should not:exceed 30%. ,,, . .. . 0. Air velocj&y ,, (1) lumuuux The air velocities used ‘inthe blowing dust (small particle) test procedure include a minimum air velooity to maintain teat conditions (1.5 m/s or 300 ft/min) and a higher air velocity typical of desert winds (8.9 m/s or 1750 ft/min) that shall be used for ! S O S t tests.
Other air velocities may be used, but test chamber limitation must be copaidered. Excessively high air velocities may leesen the caking or C10&3ing caused by. lower air velocities. : (2) &U!@&W@ An air velocity in the range of 18 to 29 la (3540 to 57OO ftlmin) is sug~ested for most blowing aand applications.~/ Winds of 18 m/a that would blow.the large particles are common, and guata up to 29 m/a are not uncommon. Other.air velocities may be used if the induced flow velocity around the equipment in its field application is known. ,,. d. ~. c , , (1) The small-particle (blowing dust) procedure may be conducted with either of the followingidustcompositions,by weight.
(a) Red china clay is oommon throughout muoh o f the world and containa: CaC03, MgC03, CaO, MgO, Na20, TI02,.etc. 5% . Ferric oxide (Fe203) ,, .10 *5% Aluminum oxide (A1203) 2O*1O% Silicon dioxide (Si02) remaining percentage U From MIL-STD-21O. METHOD “51O.2 19 July 1983 510.2-3