Downloaded from https://www.everyspec.com MIL-STD-81OD 19 ,July 1983 Step 6. Microphone Placement. Establish three reference planes perpendicular to the longitudinal axis of the store at positions one-sixth, one-half, and five sixths of the length of the store. In each of these, reference planes, position three microphones around the store, 120,0apart. Each microphone shall be within 45 cm (18 inohes) of the store aurfa’ce,“but’ further from the store than one-half the distance between the .atoreand,the neareat baffle. no SDectrum Control. The response of the‘microphones in each reference plane shall be averaged to give an average noise spectrum for each reference’piane.
The average noise spectrum for each reference plane shall be 9haped to be within -3 dB and +6 dB tinlessotherwise atated. . Step 7. Go to appropriate test procedure. II-3. ~ .. . . 11-3.1 test Step 1. Mount teat item in test chamber and position inatrumentation as given in II-2. ,, Step 2. Expose test item to the required acoustic levels and spectra for the specified amount of time as in I-3.2.3., The test item shall not be energized during Step 2. Step 3. Check test item for loose parts, chafed wires, and any other obvious damage. Correct or repair before proceeding to Step 4. Step 4.. Energize test item. Check test item functione for proper operations. Correct or repair any damage. Step 5.
Expose test item to the required acoustic noise for the specified amount of time with the test item being functioned as if it were in actual operation or flight. Step 6. Check test item for loose parts, chafed wires, and any other obvious damage. Step 7. Repair or correct as necessary before flight teeting. Step 8. Document test as in II-4. 11-3.2 Procedure II Qua ~. ~. n test . Step 1.. Mount test item as given in II-2. Step 2. Position instrumentation as specified in’II-2. : Step 3. Function the test item as if it was in operational or flight usage while being exposed to acoustic lev61s in Step 4. Step 4. Expose test item to functional test levels as in I-3..2.
MSTHOD 515.3 19 ,July1983 515.3-14