Downloaded from https://www.everyspec.com MIL-STD-81OD‘ 19’July 1983 ,.,,., .,, , .001 .- . . PSD gzlnz . ,, 1 50 Frequenty (Hz) ,. . . old Derformance random mratlon sDectrum f= S2Jl!dio ment installed ‘ins~on-comba~. FIGURE 514.3-34. 1-3.2.12 10 - ~n~tearitv ~. v The following information is provided for developing a test program.for items’which will not encounter any of the other vibration environments listed in tsble 514.3-1 and for items mounted on vibration isolation devices (I-4.10). The test program may include a secured-cargo teat from paragraph I-3.2.1, since all material.is subject to transportation from the point of manufacture to point of use.
Additional testing’will be needed if the stresses experienced in the secured cargo test will not assure adequate performance during application. The additional vibration tests are for helicopter and aircraftlexternal atore equipment applications. These vibration levels are f DUIId in figures 514.3-35 and 514.3-36 and have no relationship whatsoever to the application environment. However, historical experience has ahown that equipment which can withstand these.test conditions can function satisfactorily in the field.
These expoaurea “aresometimes called Tfjunkleveltttests and provide some assurance thatthe “equipmentcan witbetand operationa and handling during removal and repair, but certain risks must also be asaumed“without further comprehensive testing. For helicopter applications, this test should only be applied to electronic boxes which have first natural frequencies, as installed in the helicopter, greater than 100 Hz, ‘andwhich weigh less than 75 pounda.’ The weight penalty associated with this unrealistic test begins to become significant for electronic boxes that weigh more than 75 pounds. a. Test level.
The teat levels shown in figures 514.3-35 and 514.3-36 are baaed upon a variety of platforms. o b. lk& duraW. 514.3-VII. The tiUI@Df The su~ested test durations are provided in table exposure can be varied to meet the test requirements. 19 July 1983 514.3-55 METHOD 514.3