1、MIL-I-25623B15 February 1990SUPERSEDINGMIL-I-25623A5 MAY 1961MILIARY SPECIFICATION1I INDICATOR,ELECTRICAL TACHOMETERThis specificationis approved for use by allDepartment and Agencies of the Department ofDefense.1. SCOPE1.1 Scope. This specificationcovers one type of hermetically sealed, remoteindic
2、ating percent speed tachometer indicator.I 2. APPLICABLE DOCUMENTS2.1 Government documents.2.1.1 Specifications and standards. The following specificationsand standard forma part of this document to the extent specified herein. Unless otherwise specified,the issues of these documents are those liste
3、d in the issue of the Department ofDefense Index of Specificationsand Standards (DODISS)and supplement thereto, citedin the solicitation (see 6.2).SPECIFICATIONSFederalPPP-B-601 Boxes, Wood, Cleated PlywoodBeneficial comments (recommendations,additions, deletions) and any pertinentdata which may be
4、of use in improving this document should be addressed to:Oklahoma City Air Logistics Center/MMEOR,Tinker AFB OK 73145-5990by usingthe self-addressedStandardizationDocument ImprovementProposal (DD Form 1426)appearing at the end of this document or by letter.AMSC N/A FSC 6620DISTRIBUTION STATEMENT X.
5、Distribution authorized to U.S. Government agencies andprivate individuals or enterpriseseligible to obtain export-controlledtechnicaldata in accordance with regulations implementing 10 U.S.C. 140c, 13 April 1988.“ControllingDoD Office is OC-ALC/MMEOR,Tinker AFB OK 73145-5990.WAKNING. This document
6、contains technical data whose export is restricted by theArms Export Control Act (Title 22, U.S.C., Sec. 2751 et seq.) or Executive Order12470. Violations of these export laws are subject to severe criminal penalties.tiESTRUCTIONNonc13. For classified documents follow the procedure in DoD 5200.22-M,
7、Industrial Security Manual, Section 11-19 or DoD 5200.1-R, InformationSecurityProgram Regulation, Chapter IX. For unclassified limited documents, destroy by anymethod that will prevent disclosure of contents or reconstructionof the document.Provided by IHSNot for ResaleNo reproduction or networking
8、permitted without license from IHS-,-,-PPP-B-636MilitaryMIL-P-116MIL-S-7742MIL-G-9398MIL-G-26611MTL-I-25623BBox, Shipi.ng.FiherhoardPreservation,Method OfScrew Threads, Standard.Optimum Selected Series,General Specification WorGenerator, Tachometer, Two-Dole,High Temperature,AircraftGenerator, Tacho
9、meter, (XH_J-7/AMi.ni.atureSTANDARDSFederalFED-STD- 595 ColorsMilitaryDOD-STD-1OOMTL-STD-129MIL-STD-130MIL-STD-81OCMIL-STD-838MIL-STD-89MTL-sTr)-970MIL-STD-2073/lAMS33558MS33585MS33639MS33678Engineering l)rawingPracticesMarking For Shirment And StorageIdentification Marking Of U.S.Mi.lj.taryProDerty
10、Environmental Test MethorlsLubrication Of Military ?utpmentDissimilar MetalsStandards (1) Roog temperature - 0.525 volt (V) at 150 cycles per minute (CPM).(2) -54” C temperature - 0.60V at 150 CPM.Sqale error - Scale error operation at room temperature,-54 C, -35 C,5-C, and +71C temperatures in acco
11、rdancewith tables I and II.Friction error - Friction error not to exceed 1.5 percent at the 5-percentgraduation, 0.7 percent at the 20-percentgraduation, and 0.5 percent atthe 40-, 70-, 85-, and 100-percentgraduations.Position error - Position error not to exceed 0.3 percent when positioned45 degree
12、s each way from the normal operating positionwith the indicatoroperating at 100-percentindication.Pointer alignment - On subdial indicatorswhen the main pointer indicates90 and 96 percent, the subdial pointer shall indicate O and 6 percent,respectively,within 0.20 percent.Sealing - Case leakage not
13、to exceed 0.01 micro cubic foot per hour whenthe filling medium is nitrogen and helium and 0.1 micro cubic foot per hourwhen the filling medium is 100-percenthelium.Dielectric strength -Withstand test voltage of 400V root mean square (RMS)for a period of 5 seconds between connector pins and any meta
14、l part of caseor connector shell.Magnetic effect. Subject the indicator, operating at 90 percent RPM andnonoperating, rotated in increments of 45 degrees from normal, andpositioned 5.50 inches from the center of a free-magnet compass having afield intensity of 0.17 to 0.19 oersted, without deflectin
15、g the compassmore than 3 degrees.Vibration. Subjected to circular vibration in a plane inclined 45degrees to the horizontal under the following conditions:4Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-I-25623BTABLE 1. Calibrationscale errors.G
16、enerator Correct Scale errordrive shaft indicated tolerance Scale error tolerancespeed speed ROOIQtemperature -35 c -54 c +71 c -5 cRPM +Percent RPMPercent RPM . +Percent RPM1/ o 0 0.!5 0.6 0.6 0.5 0.6/ 210 5 0.5 0.6 0.6 0.5 0.61/ 420 10 0.5 0.6 0.6 0.5 0.6630 15 0.5 - - - -1/ 840 20 0.5 0.6 0.7 0.5
17、 0.61,260 30 0.6 - - - -1/1,680 40 0.8 1.1 1.2 1.0 1.12,100 50 0.8 - - - -/2,520 60 0.8 1.2 1.4 1.0 1.12,940 70 0.8 - - - -1/3,150 75 005 1.0 1.3 0.8 0.8/3,360 80 005 1.0 1.4 0.8 0.81/3,570 85 0.5 1*O 1.4 0.8 0.91/3,780 90 0.5 1.1 1.5 0.8 0.9/3,990 95 005 101 1.5 0.8 0.91/4,200 100 0.5 1.1 1*5 0.8 0
18、.91/4,410 105 0.5 1.2 1.6 0.8 1.04,620 110 065 - - - -1/ See 4.6.115Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-I-25623BTABLE 11. Calibration scale errors.Scale errorCorrect Tolerance Scale error toleranceSpeed indication Room temperature -35
19、” c -54 c +71 c -5CRPM Percent RPM +Percent RPM +Percent RPM .1/ o 0 0.5 006 0.6 0.5 0.61/ 200 4.76 0.5 0.6 0.6 0.5 0.61/ 400 9.52 O*5 0.6 0.6 0.5 0.6600 14.29 0.5 - - - -/ 800 19.05 0.5 0.6 0.7 0.5 0.61,200 28.57 0.6 - - - -1/1,600 38.10 0.8 1.1 1.2 1.0 1.12,000 47.62 0.8 - - - -1/2,400 57.14 0.8 1
20、.2 1.4 1.0 1.12,800 66.67 0.8 - - - -1/3,200 76.19 0.5 1.0 1.3 0.8 0.81/3,400 80.95 0.5 1.0 1.4 0.8 0.81/3,600 85.71 0.5 1.0 1.4 0.8 0.91/3,800 90.48 0.5 1.1 1.5 0.8 0.91/4,000 95.24 0.5 1.1 1.5 0.8 0.91/4,200 100.00 0.5 1.1 1.5 0.8 0.9/4,400 104.76 0.5 1.2 1.5 0.8 0.94,600 109.52 0.5 - - - -1/ See
21、4.6.11Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-(j)(k.)(1)(m)(n)(o)(P)(q)(r)MIL-I-25623B(1) Error. Shall not exceed 0.7 Dercent RPM when operating at a Dointbetween 60 and 90 percent RPM and at an ampltude of 0.00Q to 0.011inch while the freque
22、ncy is varied from 5 to 50 Hertz (HZ).(2) Failure. No evidence of failure when operated at 50 percent RPMand vibrated for 3 hours at an amplitude of 0.018 to 0.020 inchwhile the frequency is cycled between 5 and 50 Hz and return onceeach hour during this test.Indicator current. The current drawn bv
23、each of the 3-phase windingsshall not exceed 0.3 ampere when connected to 21V 4,200 CPM supply.Temperature. Subjected to temperature ranging from -62 C to +R5 Cwithout failure.Overspeed and reverse operation. Subiected to a generator-shaft speedof 5,000 RPM for 5 minutes and then operated in the rev
24、erse direction ata generator-shaft speed of 2,500 RPM for 1 minute without exceeding ascale error of 0.5 percent.Endurance. Subjected to 1,000 hours oneration at 90 +5 Dercentindication without damace. Thermal shock. Suhiected to 4 cvcles of exposure to water bathsmaintained at a temperature of 85 +
25、2 C and 5 +2” C without evidenceof leakage when sub.iectedto the sealing test. Precipitation. Subiected for a period of 2 hours at an ambienttemperature of 85 +2 c, and then immediately ?mmersed “in a liquidbath maintained at 0= to 5“ C without evidence of moisture deposit onthe inner face of the co
26、ver glass.Fogging. Suhiected to 70+20 C controlled temperature for a minimum of1 hour, and then the inriictorglass face immediately rubbed with an icecube while at this temperature without evidence of”moisture or oil foggtn.Salt fog. Subiected to salt fog for a period of 50 hours in accordancewith 4
27、.6.25 without evidence of external corrosion or deteriorationaffecting subsequent operation.Internal examination. Subiected to examination internally for corrosion,deterioration, or damage resulting from all tests ,sDecifiedherein.3.6 Interchangeability. All.parts having the same manufacturers part
28、number shallbe directly and completely interchangeable with each other with resDect toinstallation and performance. Changes in manufacturers part numbers shall hegoverned by the drawing number requirements of Specification DOD-STD-1OO.3.7 Case. The case shall be in accordance with figure 1 and shall
29、 movide ahemietically sealed enclosure for the internal mechanism of the indi=tor Thedesign of the case shall be such that the internal mechanism-may be removed from thecase, replaced, and the case resealed. This shall he accomplished without the useof special tools and fixtures unless thev are apvr
30、oved hv the contracting actfvftv.The hermetic sealing shall be so accomplished that the actj.onof anv atmosphere towhich the indicator may be subiected. The distance between the outer surface of the. 7Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-M
31、IL-I-25623B.-DIALBREhK EOGE 7.OI.ORAD APFROXtlExamination of productRoom temperature startingScale error at room temperatureFriction error .Position errorPointer alignmentSealingPrecipitation(4.6.1)(4.6.2) (4.6.3)(4.6.4)(4.6.5)(4.6.6)(4.6.7)(4.6.8)4.4.2 Sampling plans and tests. -.4.4.2.1 Sampling p
32、lan A. One indicator selected at random from each”100 or lessproduced on the contract or order shall be subjected to the following tests:(a)(b)(c)(d)(e)(f)(g)(h)(i)(j)Individual testsLow temperature startingScale error at -54 CScale error at -35 CScale error at -5 CScale error at high temperatureDie
33、lectric strengthMagnetic effectVibration errorFogging(4.4.1)(4.6.10)(4.6.11)(4.6.12)(4.6.13)(4.6.14)(4.6.15)(4.6.16)(4.6.17)(4.6.9)4.4.2.2 Sampling plan B. Unless otherwise specified, 3 indicators selected atrandom from the first 15 items of the contract or order shall be subjected to thefollowing t
34、ests:(a)(b)(c)(d)(e)(f)(g)(h)(i)Indicator currentLow-temperatureexposureHigh-temperatureexposureVibration failureOverspeed and reverse operationIndicator enduranceThermal shockSalt fogInternal examination(4.6.18)(4.6.19)(4.6.20)(4.6.21)(4.6.22)(4.6.23)(4.6.24)(4.6.25)(4.6.26)4.4.2.3 Rejection and re
35、test. When one item selected from a production run failsto conform to this specification,no items still on hand or later produced shall be13Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-I-25623Baccepted until the extent and cause of failure are
36、 determined. After correctionshave been made, all necessary tests shall be repeated.4.4.2.3.1 Individual tests may-continue. For operational and production reasons,individual tests may be continued pending the investigationof a sampling testfailure. But final acceptance of items on hand or later pro
37、duced shall not be madeuntil it is determined that items conform to the new specification.4.4.3 Defects in items already accepted. The investigationof a test failure couldindicate that defects may exist in items already accepted. If so, the contractorshall fully advise the contracting activity of al
38、l defects likely to be found andmethods of correcting them.4.5 Inspection conditions. Unless otherwise specified, all inspections shall beperformed in accordance with the test conditions specified in 4.5.1 in thisspecification.4.5.1 Standard atmospheric conditions. Whenever the pressure and temperat
39、ureexisting at the time of the test are not specified definitely, it is understood thatthe test is to be made at atmospheric pressure (approximately29.92 inches Hg) andat room temperature (approximately25” C). When tests are made with atmosphericpressure or room temperature differingmaterially from
40、the above values, properallowance shall be made for the difference from the specified conditions.4.5.2 Tapping. Except where otherwise specified, the indicator shall be gentlytapped or vibrated before a test reading is taken.4.5.3 Vibration. Unless otherwise specified, the indicator shall be subject
41、ed tocircular vibration in a plane inclined 45 degrees to the horizontal plane. Thevibration shall be within a frequency range of 5 to 50 Hz and at amplitudeswithin0.009 to 0.020 inch.4.5.4 Attitude. Unless otherwise specified, the indicator shall be tested in itsnormal operating position (dial surf
42、ace shall be held in vertical plane).4.5.5 Test voltage. Unless otherwise specified, voltages noted herein arealternating current root-mean-squarevalues. The voltmeter used to measure voltagesshall be of a type which is free from frequency errors.4.6 Test Methods.4.6.1 Examination of product. Each i
43、ndicator shall be inspected to determinecompliancewith the requirements specifiedherein with respect to materials,workmanship, proper operation, and performance=4.6.2 Room-temperaturestarting. The indicator shall be connected to avariable-frequencypower supply. The supply voltage shall be 0.0035 tim
44、es thefrequency in CPM. The frequency of the supply shall be increased from zero CPM upto but not exceeding 150 CPM. The indicatormay be gently tapped or vibrated and areadingmade from the indicator. The reading shall be not less than 2.5 percentRPM.4.6.3 Scale error at room temperature. The indicat
45、or shall be connected as shownon figure 2 to a generator conforming to SpecificationMIL-G-9398 or MIL-G-26611 andtested at points of the scale indicated in either table I or table 11. The testshall be made either by driving the generator at a speed to produce the specified14Provided by IHSNot for Re
46、saleNo reproduction or networking permitted without license from IHS-,-,-MIL-I-25623Bindicator readings and reading the speed of the generator or hy driving thegenerator at the specified speeds and reading the indicator. The test shall.he madewith speeds increasing, then with speeds decreasing. Wjth
47、 speeds increasing, thespeed shall be brought UP to hut shall.not exceed the speed specified to give thedesired reading, and with speeds decreasing, the speed shall be brought down to hutshall not fall below the sQeed specified to give the desred reading.4.6.3.1 Scale error tolerance. The errors at
48、the test points shall not exceed thetolerances specified in the aplicable table. When the speed is held constant atany point of the scale, the pointer shall not oscillate over a range greater than0.5 percent from O to 15 percent and 0.3 percent from 15 to 100 nercent as indicated“onthe indicator.4-.
49、6.3.2 Test setup. In accomplishing the tests specified for the scale error test.two single indicators shall be connected to and operated from one tachometergenerator.4.6.4 Friction error.4.6.4.1 Friction error tolerances. The indicator shall.he set at 5-, 20-, 40-,70-, 85-, and 100- percent graduations,
