Downloaded from https://www.everyspec.com MIL-STD-8,1OD 19 July 1983 11:2:3.2 ,. w.ronment urofile charts. For each of the’controlled environments, prepare a chart plotting stimuluslevel versus time that best represent the . composite rnisaion. Each chart shou’ldbe based on a standard atmosphere and’the time period for the composite mission. These plots define the basic environment profiles that constitute a single test cycle and,provide the patterna for controlling the environmental test apparatus”. Me,thods,for “generating‘composite mission environmeritalprofiles are discussed in I-2.3~ ., II-2.3.3 Climatic offset table.
Prepare a table or chart indicating the temperature offsets applying to consecutive test cycles in a climatic set of about 6 to -15“’cycles(refer to figure 523.0-5).‘ The offsets are chosen SO that one climatic set will represent the predicted mixture of climates expected in operational missions. This prooess is discussed in I-3.4.1. ~~ 11-2.3.4 c~!. b r Provide directions for adjusting each of the coritrolledenvironments throughout each complete climatic set of teat cycles. Levela are obtained from the composite mission environment profile with the temperature “patternfor each cycle of the climatic set offset according to plan.
These directions”should not be finalized until test’setup is completed (see II-2.4, next). 1172.4‘ lest set~ 11-2”’:4’.1 .(M. eral. Using instrumented (but not necessarily operable) stores, aasemble test items and environmental’apparatus, with accompanying instrumentation’and controls, into the planned configuration. After s“enaor’ calibrations, test each environment separately to check ability to reach test levels and rate-of-change,requirementa. With individual environments checked , out, run combined environments through a test cycle. Correct problems as necessary. The general accuracy and tolerance requirements of section 4’of this standard shall be,followed where applicable.
II-2.4.2 Ubration c&.Q@&. Adjustment of the vibration ao’urceat6 provide the,best simulation of in-flight vibration response is an essential part of teat setup. Vibration response simulation can involve the following types of error: spatial (relative distribution of levels among various locations and in different directions in or’on the store)”,spectral (frequency ap&trum shape at any location and direction in or on the store), and intensity,.(peakand rms values).
~An iterative process of adjusting vibration atimulua’variables (intensity, ‘spectralenvelope, limited directivity/store“positioning) and observing responses”is conducted to minimize these errors~ The goal is ,t,o find the ,stimulusadjustments for each test level which will’optimize the correlation of ,test setup with corresponding“captive-flighttotai”vibratiori responses. Optimum”’values are noted and made part of the Combined Environments Control Directions (II-2.3.4). 11-2.5 Oeratlonal We&2.&. Replace instrumented stores with one or more operable “practicer!stores.
Provide input power as required and use perform- ance monitoring system at room environment and then, if required, during one’ Or more mission test cycles of combined environments. Debug,as necessary. . ,.~ z> .. . . ,,..... . . 19 Jllly’1983 523.0-17 METHOD 523.0 ,::y ,