Downloaded from https://www.everyspec.com MIL-STD-81OD 19 July 1983 c. yIZ: Top of test item facing toward oenti.rof Centrifuge. d. QQMU: Reverse item 180 degrees from up position. e. ~teral left: Left side of test item facingtoward center of centrifuge. f. Latera1 r- : Right side of test item facing toward center of centrifuge. After the test item is properly oriented and mounted on the centrifuge, measurements and calculations must be made to assure that the end of the teat i item nearest to the center of the centrifuge will be subjected tc nc leas than 90 percent of the ‘glevel established for the test.
If the g level is found to be less than 90 percent of the established g level, the teat item must be mounted further out on the.centrifuge arm and the rotational speed adjusted according y or a larger centrifuge used so that the end of the “test item . nearest to the center of the centrifuge is Subjected to at least 90 perce”ntof the established g level. However, the opposite end of the test item (the.end farthest from the center of the centrifuge) should not be subjected to over 110 percent of the established g level. For large test items, exceptions shculd be made for load gradients based on the existing availability of large centrifuges in commercial or government test facilities.
II-2.2.2 BOcket-nawed sled mOuntti. For rocket-powered sled mounting, the test item and associated test fixture or apparatua shall be mcunted on the sled platform in accordance with the controlled acceleration direction of the sled. (The tegt fixture or apparatus should have been designed to isolate sled vibrations from the test item.) Since the sled and test item experience the o cameg levels, only the orientation of the test item cn the sled is critical. The orientation of the test item cn the sled shall be according to the acceleration directions shown in figure 513.3-1 and the controlled acceleration directicn of the soledfor the,six test directions. II-2.3 Functional cretz.
After the test item ia mounted on the test apparatus, a complete functional test shall be made on the test item to assure that the test item complies to the specification requirements. Record functional performance, observed data, and other pertinent.information. Failure of the item to comply to specifications is cauae for rejecticn for teat. Fcr Procedure I (Structural Test), the functional pretest may be performed prior to mounting the test item on the test apparatus.
However, fcr Procedure II (Operational Test), the functional pretest should be performed after the ,, test item is mcunted on the test apparat’uato assure that the test item is prcperly installed fcr operaticn during the Procedure 11 teets. METHOD 5’13.3 19 July 1983 513.3-12