1、MILITARY SPECIFICATION Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use In improving this document should be addressed to: Oklahoma City Air Logistics Center /MMEOR, Tinker AFB OK 73145-5990 by using the self-addressed Standardization Document Im
2、provement Proposal (DD Form 1426) 1. SCOPE INDICATOR, PRESSURE EGU-g/A MIL-I-38121C (USAF) 30 November 1989 SUPERSEDING MIL-I-38121B(USAF) 31 December 1970 1.1 engine pressure ratio indicators, designated EGU-9/A. Scope. This specification covers the requirements for single remote ndicati.ng 1.2 Cla
3、ssification. 6.2): Indicators shall be of the following types, as specified (see EGU-9 /A- 1 EGU-9/A-2 EGU-9/A-3 Nonintegrally Lighted Integrally Lighted Red Integrallv Lighted White 2. APPLICABLE DOCUMENTS 2.1 Government documents. 2.1.1 Specifications and standards. The following specifications an
4、d standards form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are those listed in the issue of the Department of Defense Index of Specifications and Standards (DODISS) and suuplement thereto, cited in the solicitation (see 6.2). DI
5、STRIBUTION STATEMENT X. - Distribution authorized to U. S. Government agencies and private individuals of enterprises eligible to ohtain export-controlled technical data in accordance with regulations implementing 10 U.S.C. 14Oc, 13 April 198. Controlling DoD Office .is OC-ALC/MMEOR, Tinker AFB, OK
6、73145-5990. WARNING - This document contains technical data, the export of which is restricted by the Arms Export Control Act (Title 22, U.S.C., Sec. 2751 et seq) or the Export Administration Act of 1979, as amended (Title 50, U.S.C., Aup. 2401 et seq). Violations of ,these export laws are subject t
7、o severe criminal Denalties, DESTRUCTION NOTICE - Destroy by any method that will prevent disclosure of contents or reconstruction of the document. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. t MIL-I-38121C (USAF) d 2.1.2 Other Government docum
8、ents, drawings, and publications. The following other Government documents, drawings, and publications form a part of this document to the extent specified herein. Unless otli-rwise cr,-ci the issue are those cited in the solicitation. AF Drawing 8988994 Luminescent Material, Fluorescent. (Applicato
9、n for copies should be addressed to the OC-ALC/MMIRF, Tinker AFB, OK 73 145-5990. ) SPECIFICATIONS Fe dera 1 PPP-B-60 1 PPP-B-636 Military MIL-P-116 MIL-1-7057 MIL-A-862 5 MIL-L-25467 MIL-L-27160 STANDARDS FED-STD-595 Military MIL-STD-129 MIL-STD-130 MIL-STD-4 70 MIL-STD-704 MIL-STD-781 MIL-STD-785
10、MIL-STD-810C MIL-STD-889 MIL-STD-970 MS 33 5 58 MS33585 MS 3 3 6 78 Boxes, Wood, Cleated Plywood Box, Shipping, Fiberboard Preservation, Methods Of Indicator, Synchro, Aircraft, General Specification, For Anodic Coatings, For Aluminum And Aluminum Alloys Lighting, Integral, Red, Aircraft Instrument,
11、 General Specification For Lighting, Instrument, Integral, White, General Specification For Colors Marking For Shipment And Storage Identification Marking Of U. S. Military Property Maintainability Program Requirements (For Systems And Equipments) Aircraft Electric Power Characteristics Reliability
12、Testing For Engineering Development, Qualification, rees shall be linear within + 10“ 15 of arc. - 3.5.2 Integral lighting. The indicator shall he designed for inteeral liehtine: in accordance with MZL-L-25467 or MIL-L-27160, as applicable. 3.5.3 Reliability. EngineerinR for Reliability shall occur
13、simultaneouslv with engineering to achieve electrical and mechanical characteristics. The eauipment lower test mean-time-between-failure (MTBF), shall not he less than 4000 hours. Failure refers to any condition of the equipment whereby full operational service, as required herein, is not possible.
14、3.5.4 Maintainability. The indicator shall be maintainable within the general parameters of MIL-STD-470. 3.6 Performance. The performance of the indicator shall he within the tolerances specified in tables I and II when connected to a master transmitter energized at 26 - + 0.05V and 400 + 1 cycle si
15、ngle-phase power. schematic 1 shall: cause CW indicator pointer rotation. System wiring as illustrated in TABLE II, Performance Tolerances. m Test I Pressure Ratio Tolerance (+I Frequency and Voltage Variation Position Error Friction: Room Temperature Low Temperature High Temperature Pointer Oscilla
16、tion Pointer Variation Vibration: Counter and Pointer Index Cycling 0.005 O. O05 0.005 0.010 0.010 0.010 0.010 0.010 3.6.1 The indicator shall be capable of meeting the test requirements specified herein when subjected to the following conditions: 4 Provided by IHSNot for ResaleNo reproduction or ne
17、tworking permitted without license from IHS-,-,-MIL-I-38121C (USAF) . - -_ U O k w shall remain approximately in phase with the rotor voltage E(R R 1. within 0.010 inch of the electrical zero reference mark. At eiectrical zero, the tip of the pointer shall be 21 4.6.3 Scale error and friction. Durin
18、g the scale error test, the indicator can be connected to a master transmitter especially designed for this type of testing. master transmitter shall not have an error of more that 0.05 circular degrees and shall be furnished with a correction table so that the correct transmitter position can be de
19、termined within 0.05 circular degrees. readings required to provide the respective test indicator readings listed in table I shall be set while the indicator is being gently tapped or vibrated. indicator shall be considered out of tolerance when the difference between the indicator reading and maste
20、r synchro transmitter reading exceeds the tolerance shown in table I. The indicator friction error shall be measured by setting the indicator on the respective test points shown in table I while it is gently tapped or vibrated. At each test point and without tapping or vibrating the indicator, the m
21、aster synchro transmitter shall be advanced to an angular position which is just sufficient to cause the indicator pointer to move. scanned and observed for points of excessive friction at intermediate points. . Friction error shall be considered as the difference between the master synchro transmit
22、ter setting required to produce the indicator setting while under vibration or tapping and the master syncho transmitter setting required to move the pointer without vibration or tapping. 4.6.4 Vibration. accordance with method 514.2, equipment category b.1, procedure I (part 1 only), curve B of MIL
23、-STD-810C. No malfunction of the indicator shall result from this test. Pointer oscillation and variation shall be within the tolerances specified in table II. The The corrected master transmitter The The indicator dial shall also be The indicator shall be subjected to a vibration test in 4.6.4.1 Sc
24、ale error after vibration. Following the vibration test, the indicator shall be checked for scale error and friction. The room temperature tolerances specified in table I and II shall apply. 4.6.5 Low temperature. subjected to -55“ + 2“ C for a period of 4 hours. while still at thespecified temperat
25、ure, the indicator shall be subjected to the test specified in 4.6.3. The scale errors shown by the indicators shall not exceed the tolerances specified in tables I and II. The indicator shall be returned to room temperature for a minimum period of 4 hours and again subjected to the scale error at r
26、oom temperature test. The scale error shall not exceed the tolerance specified in table I. 4.6.6 High temperature. The indicator shall be placed in a test chamber and subjected to a temperature of 71“ + 2“ C for a period of 4 hours. this period and while still at this temperature, the indicator shal
27、l be subjected to the test specified in 4.6.3. The scale errors shall not exceed the tolerances specified in tables I and II. The indicator shall be returned to room temperature for a minimum period of 4 hours and again subjected to the scale error at room temperature test. I. The indicator shall be
28、 placed in a test chamber and At the end of this period and / At the end of The scale error shall not exceed the tolerance specified in table 4.6.7 Magnetic effect. The indicator, operating on rated voltaRe, shall be rotated in a vertical plane about a short bar magnetic compass with the nearest par
29、t of the indicator 5 5 0.50 inch from the magnetically east or west of the center of the compass. Starting directly under the compass, the indicator shall be held in 13 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. MIL-I-38121C (USAF) 1 O positio
30、n O, 45O, 90, 135O, 180, 225“, 270, and 315“ from the initial position. At each of these positions, the indicator shall be rotated about its own horizontal axis until it is in its normal viewing position. intensity shall be 0.17 to 0.19 oersted. the specified positions shall not exceed 3“. The horiz
31、ontal magnetic fieicl The deflect:.):. of the compass at any of 4.6.8 specified in 4.6.3 and the input power varied to provide any combination of the Voltage and frequency variation. The indicator shall be subjected to the test following voltages and frequencies. The indicator scale errors at the va
32、ried voltages and frequencies shall not exceed the tolerances specified in table II. a. 22 to 30V bo 380 to 42OHz 4.6.9 Fogging. The indicator shall be energized and in a controlled ambient of 70 - + 2C for minimum of 1 hour. temperature, an ice cube made of distilled water and of nominal original s
33、ize, 1 by 1 inch, with its flat surface 1 by 1 inch, shall be rubbed over a major area of the indicator glass face from 1 to 2 minutes. If the ice cube melts to an unusable size before this test is completed. The glass shall be wiped dry (compressed air shall not be used) and the indicator inspected
34、 for evidence of internal water or oil fog. rejection . At the end of this period and while at the specified A second ice cube shall be used. Evidence of fogging shall be cause for 4.6.10 Sealing. means of a mass-spectrometer type helium leak detector. mixture is utilized as the filling medium, the
35、detected leak rate shall not exceed 0.1 micron cubic foot per hour at a pressure differential of 1 atmosphere. 100 percent helium is utilized as the filling medium, the leak rate shall not exceed 1.0 micron cubic foot per hour. The hermetically sealed indicator shall be tested for leaks by Where a n
36、itrogen-helium Where 4.6.11 chamber and subjected to a temperature of -65O+ 2C for a period of 48 hours. at this temperature, no operational test shallbe performed. be raised to -54“+2OC and maintained for 24 hours. indicator shall be subjected to the error test at the test points specified in table
37、 I. returned to room temperature foF a minimum period of 4 hours and subjected to the test specified in 4.6.3. Extreme low temperature exposure. The indicator shall be placed in a test While The temperature shall While still at -54“ + 2“ C, the The indicator shall be A scale error tolerance of + 0.0
38、05 EPR shall apply. 4.6.12 Extreme high temperature exposure. The indicator shall be placed in a chamber.and subjected to a temperature of 85 + 2“ C for a period of 24 hours. Normal instrumentation power shall be applied Continuously the last 2 hours of this period. While still at the specified temp
39、erature, the indicator shall be operated throughout its range and shall exhibit no sticking or erratic characteristics. The temperature shall then be lowered to 71“ + 2OC for a 4 hour period and the indicator subjected to the high temperature test; the tolerances specified in tables I and II shall a
40、pply. The indicator shall be returned to room temperature for a minimum period of 2 hours, then subjected to the scale error at room temperature test. The scale errors shall not exceed the tolerances specified in table I. . 4.6.13 Counter and index pointer cycling. The set knob shall be turned conti
41、nuously in order to move the takeoff index and counter from 1.1 to 2.3 + 0.1 and return to 1.1 + 0.1 pressure ratio units. This procedure shall he considered one cycle of operation. The total cycling period shall be a minimum of 2,500 cycles 14 Provided by IHSNot for ResaleNo reproduction or network
42、ing permitted without license from IHS-,-,-MIL-I-38121C (USAF) and shall be conducted at a cycling rate of 2 + 0.2 Hz. the torque required to turn the control knob shall be measured and recorded. The allowable torque required to turn the control knob throughout the range of 1.0 to 2.5 pressure ratio
43、 units shall not exceed 6 + 3 ounce-inches. 4.6.13.1 operation inspection shall be conducted to assure that binding, deformation, and malfunction are not evident. throughout the range of 1.0 to 2.5 pressure ratio units shall not exceed the measurements recorded at the start of the cycling test by mo
44、re than 2 ounce-inches. Prior to the cycling test, - Upon completion of the 2,500-cycle testing, physical and functional The torque required to turn the control knob 4-6-14 Salt fog. The indicator shall be subjected to a salt fog test in accordance with method 509.1, procedure I of MIL-STD-810C for
45、a 50-hour period. error at room temperature test shall be conducted immediately before and after this test. temperature. Subsequent indicator operation shall not be affected by this test, and excessive corrosion of metal parts, including electrical receptacles, shall be cause for rejection. The scal
46、e The scale error tolerances shall not exceed those specified for room 4-6-15 Reliability. The indicator shall be subjected to a reliability demonstration at the following conditions of temperature, vibration, and input voltage. the test: The cycling of these conditions shall be applied to the equip
47、ment during a. Temperature: -55“ C to +85 C (-67 F to +185“ F) b. low temperature followed by time to stabilize at the high temperature, plus two hours. Stabilize the equipment temperature at the lower test level temperature Turn the equipment on and allow it to experience the combined effect of cha
48、mber heating and equipment operation until the point of maximum thermal inertia stabilizes at the higher temperature, that is, when the rate of thermal change is less than 2“ C/hr. Maintain the equipment at the upper test level temperature for a period of two hours. Turn the equipment off and allow
49、it to experience chamber cooling until the point of maximum thermal inertia stabilizes at the lower test level temperature. This cycle shall continue for the duration of the test. Temperature cycling: Temperature cycling shall be time to stabilize at C. Vibration: The equipment shall be subjected to a swept sinusoidal vibration conforming to curve AR of Fig. 514 2-2 of MIL-STD-alOC, Method 514.2. The equipment shall be swept from 5 - 2000 Hz within 15 minutes. shall be applied 15 minu
