Downloaded from https://www.everyspec.com MIL-STD-81OC 3.1.1 Test item orientation (centrifuge). Wlen a centrifuge is used to attain.the required acceleration levels, the test item shall be oriented as follbws: Fore: Front or forward end of test item centrifuge. shall face toward center of Aft: Reverse item 180 degrees from the fore position. up: Top of specimen shall face toward center of centrifuge. o Down: Reverse item 180 degrees from the up position. Lateral: Each side (right, left) in turn shal1 face toward center.of centrifuge. 3.2 Test level determination. The G level to be applied to the test item is contingent on two factors:
The direction of forward acceleration level A of the vehicle, and the orientation of the test item within the vehicle. Where: A = The highest possible known or unknown forward accelerationof a vehicle in which equipment is to be mounted. A shall never be less than one g, whe~e g is acceleration due to gravity. Instructionsfor selection 513.2-I, and for procedure of test levels for procedure I from table 11 from table 513.2-11 are as follows: Forward Orientation accel.
of of test item vehicle in vehicle Test level Known Known Substitute known accelerationA in forward acceleration column of appropriatevehicle category, and use given multiplying factors attain test level for indicated directions. to Known Unknown Substitute known accelerationA in forward acceleration column of aum-opriate category, and use largest given mui~ipiying facto= to attain test level for all directions. Unknown Known Select most probable level from those given in forward acceleration column of appropriate category, and use given multiplying factors tO test level for required direction. MSTHOD 513’.2 513.2-2 [