1、. . . -. . -. . . . - . . . - .- - NIL-A-6752A 66 W 7799706 0325705 T /- . M I t -A - 6 7 52 A (U SG) . 24DECEMBER 1953 . Superseding . MIL-A-67 52 . . . . . June 1950 9 December 1949 MILA-P2S( USAF) , . .-. . . . . . -. . r.: MILITARY SPECIFICATION . AMMETERS, VOLTMETERS, AM) LOADMXTEEtS; DIRECT CU
2、RRENT This specification has been approved by the Department of the Air Force and by the Navy Bureau of Aeronautics. 1. SCOPE . _-_ . . 1.1 This specification covers the general requirexents of d-c voltmeters, and . . of SO-millivolt d-c ammeters arxi loadmeters used in military aircraft. . . -. . .
3、 . . . . . . . 2. APPLICABLE DOCUMENTS . -. * 2.1 The following specifications, standards, drawings, and publications, of the issue in effect on date of invitation for bids, form a part of this specification: SPECIFICATIONS . . . . . . . Military I . I MIL-D-928 -_ .-. . MIL-P-6064 . MTJPS-L? . JAN-
4、S-44 . . . . . ._ . I Y. _.-. -.-.- -._ , . . , ,_ . . . . . . . . . . . . .I. . ., * .- i. 1 . - _._ . - , . . . ., . _., . ”. 1 . , . I:_:.,. .ii;iF.; .( ; . . Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-A-b752A bb = 7797706 01125708 5 . .
5、,. . . . I . . . . . . . . . I MIL-A-6752A( ASG) 3.5 Screw threads.- Screw threaas with major diameters of 0.060 inchor more shall conform to SpecifScation HIL-S-7742. .- The range of .operation for the meters shall befkm -b q direction, the pointer tip shall remain within 2 percent of total scale l
6、ength of lhe zero point. a good mechanical balance, The balapce shall be easily and readily adjustame. 3.9 Temperature influence.-. Irhe temperature influence of e meters when tested as specified herein shall not exceed the following. (a) Loadmeters 1.0 (b) Ammeters 1.0 (c) Voltmeters 0.50 3.10 Accu
7、racy., 3.10.1 Room temperature.- Unless otherwise specified on the applicable drawing, the meters shn indicate within 22 percent of full-scale deflection at room temperature of 25 25C (77“ +9F). . 3.10.2 Low temperature.- The change in reading when the meter is submitted to test at -55C 1-67F) shall
8、 not exceed 8 percent for loadmeters and ammeters and 4 percent for voltmeters. High temperature test as specified in Section 4 shall not exceed 8 perc.ent for load- meters and ammeters and 4 percent for voltmeters. or current sufficient to give full-scale momentary deflection is suddenly-applied. t
9、hey will not cause a deflection of the compass of more than 6 degrees when tested as specified in Section 4. 3.10.3 High temperature.- The change in reading when the meter is subjected te 3.11 Response time.- Response time shall not exceed 2.5 seconds when a voltage 3.12 Magnetic shielding.- The ame
10、ters shall be magnetically shielded so that 3.i3 insulation resistance.- 3.13.1 An alternating current, commercial frequency, voltage as specified below, applied for a period of 1 minute shall cause no breakdown of insulation: bj “,ete“,s llo to 120 v rms 1,ooov rms (c) Voltmeters 1,v rms The insula
11、tion resistance between all live parts and the metal panel 3.13.2 upon which the instrument is mounted shall be not less than 20 megohms at a potential of 500 volts dc. 4 ._ I . . , . , . . . I , . . -_.- - . -_ . . . . . . . . . . . . . - . . *_-.- “. . . . -. . . . . . . . . . _. . . . . . . . . .
12、 . . , . . . . . , _.-_ -_ -_,- _-.* -_.I._I-_-_ . . ._._ -. . _._.- I - . - . *, . . . _._ . . . . _ . . , . . . .- .-. . - . . . . . . . . . . , - . c.- . I . I . . . . .i . - . . . . . . -. . . - - -_-.-.- . A . ,_ _. .-_ _ . ,_.-_. _-. . - . . -._I. . . , . . i . . . . . . . II_ - . - . -._ *._
13、. .- _. _ -. . . _.- . - . “. . . .- -. . . .-. . .-. . . - . . . .- .- . ,.-i- .-,-. _.“_ . . . . . . . . . . . . : . 1: 1 . i 4 r-:.z.x.z:.: c- ,._-. .- .- . . . . L- . -.- ,.-_.-.-.I . . _ “ . . -II . -. . -.- “ - - . . . ._.-. -, .- - ._ “ . _- . . .I . . . , c_ _ . . C=:T.: . I: . . -,i f.:. I
14、. . _ - . . . t . . ._ . .- -. . .- _- - . ;:.y 2: :*: . - . . -. . i _._ . . . r i_ . -. -.-.-.-. _-_I._ -.-. _-_.- :.-.; . b I-%-.-.; . . - _-. . I_ . , . , . .- . . . . . .:i ._ . Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-A-6752A 66 = 77
15、77706 OL2571L 5 AN 32 d3V30 AN 320b VI 50 OVF,RLAP OF POINTERS TO-BE 50 -1.15 PERCENT OF MINOR GRADUATIONS MARKINGS ALL NUMERALS LETTERING (EXCEPT DC 1 DC MAJOR GRADS INTERMEIIIATE GRADS (EXCEPT 5 AND 15 OF MINOR GRADS, 21 THRU SECTOR LINE AN3203v30) 29 OF AN3203V30. INTERMEDIATE GRADS 5 AND 15 OF A
16、N3203V30 MINOR GRADS AN PART NO. HEIGHT OR LENGTH, RICH tO.010 O. 109 0.156 O. O94 0,188 0,156 0.125 - O. 156 o. 125 o. 062 WIDTH OF LINE OR GRADUATION INCH 50.005 - - -i- O. 030 o. 025 FNI SH FLUORESCENT- LUMINESCENT MATERIAL -I o. O15 0,015 o. 025 WHITE OR 0.015 NATURAL MJ3TL DURABLE DULL BLACK FI
17、GURF: 2. Volheter dials an.dmarklng : 7 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-8 OVERLAP OF POINTEXt TO BE !% PERCENT OF MINOR GRADUATIONS. HEIGHT OR INCH k001010 MARKING LENITH ALL NUMERALS 0.094 LOAD O. O94 MAJOR GRADS O*W4 INTERMEDIATE GR
18、ADS 0.062 MINOR GRADS O O31 LETTERI% 0.062 RY!F!PT T,nAn! WIDTH OF LRIE OR GRADUATION INCH ?Oo.005 0,015 0.015 O. 015 0*015 0.015 FIGURE 3 Loadmeter dial and marking TJJJORESCENT- LUMINESCENT MATERIAL I MJRABZiE DULL WHITE I DURABLE DULL BLACK Provided by IHSNot for ResaleNo reproduction or networki
19、ng permitted without license from IHS-,-,-MIL-A-6752A( ASG) 3.22 Identification of product.- The physical item shall be marked for identifi- The nameplate shall contain the cation in accordance with Standard MIL-STD-130. information presented below: Name (as applicable) AN ,or MS Part No. Specificat
20、ion MILyA-6752A Stock No. Manufactureris Part No. Manufacturers Serial No. Contract or Order Uo. Manufacturer 1 s Name or trade-mark us 3.22.1 Use of AN 0r-m designations,- AN or MIL designations shall not be applied to a product, except for Qualification test samples, nor referred to in corre- spon
21、dence, until-notice of approval has been received from the activity responsible for qualification, or from the Aeronautical. Standards Group. 3.23 Workmanship. - 3.23.1 General.- The meter, including all parts and accessories, shall be con- structed and finished in a thoroughly workmanlike manper* g
22、iven to neatness and thoroughness of soldering, wiring, markin of parts and assemblies, welding and brazing, painting, riveting, machine-screw assemblies, and freedom of parts from burrs and sharp dges. particular attention shall be 8 3.23.2 Dimensions.- Dimensions and tolerances not specified shall
23、 be as close as is consistent with the best shop practices. the interchangeability, operation, or performance of the meter, they shall be held or ljmited accordingly. Where dimensions and tolerances may affect 3.23.3 Screw assemblies.- Assembly screws and bolts shall be .tight. The word W.ghtff mean
24、s that the screw or bolt cannot be appreciably tightened further, without damage or injury to the screw or bolt or threads. 3.23.b Riveting.- Riveting operations shall be carefully performed to insure that the rivets are tight and satisfactorily headed. 3.23.5 Cleaning.- The meter shall be thoroughl
25、y cleaned of loose, spattered, or . excess solder, metal chips, and other foreign material, after final assembly. Burrs and sharp edges, as well as resin flash that may crumble, shall be removed. k. QUALITY ASSURANCE FFLOVISIOhE 4.1 Classification of tests.- The inspection and testing of meters shal
26、l be classified as follows: (a) Qualification testsi Qualification tests those tests performed on samples submitted for approval as qualified products. (b) Acceptance tests: Acceptance tests are those tests performed on individual lots which have been submitted for acceptance. 4.2 Qualification test
27、s.- 4.2.1 Sampling instructions.- The Qualification test samples shall consist of 9 eight meters of a single range upon which qualification is desired. If these meters of Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-a single range satisfactoky pas
28、s the Qualification tests specified herein, meters of the same construction but other ranges may be recammended for type approval and inclusion in the approved ltst without further test, detail parts chail be furnished with Qualification test samples, warded to the activity designated in the letter
29、of authorization from that activity (see paragraph 6.4), plainly identified by securely attached durable tags marked with the following inflormation: One assembly drawing or drawings showing Samples shall be for- Samples for Qualification Tests (Name of meter) JW or MS Part No, Manufactureris Part N
30、o. Name of manufacturer Submitted by (name) (date) for Qualification test in accordance with requirements of Specification MIL-A-6752A reference authorizing letter). 4.2.2 Testso- Qualification test samples, as specified below, shall be subjected to all the tests of this specification described unde
31、r “Test methods,“ conducted in the order listed below. Qualification tests may be supplemented with tests under actual service conditions: At the option of the activity responsible for qualification, the Test group 1 (All samples) (a) Examination of product (b) Zero adjustment (c) Balancing (d) Accu
32、racy - room temperature (f) Response time (g) Magnetic shielding (h) Temperature influence (i) Accuracy - high teverature (j) (k) Insulation resistance 1- Test group 2 (Two samples) (e) Damping Accuracy - low temperature exposure (a) Overload (b) Mounting lugs (c) Mounting nuts (1) Iomentary (2) Sus
33、tained Test groq 3 (Two samples) () Humidity conditioning (b) Humidity cycling Test group 4 (Two samples) (a) Shock (b) Vibration Test group 5 (Two samples) Supplementary tests, if necessary 4.3 Acceptance tests,- The Acceptance tests shall consist of Individual tests, Sampling tests, and Special te
34、sts. 10 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-A-6752A bb W 77777Ob 0125715 2 M MIL-A-67sZA( AS) 4.3.1 be subjected to the following tests, as described under “Test methods“ of this specification: Individual tests.- Each meter submitted
35、for acceptance under cantract shall (a) Examination of product (b) Zero adjustmerrt (c) Balancing (d) Accuracy - room temperature 4.3.2 Sampling tests.- Five meters which have been manufactured under essentially the same condtions shall be selected at random from each lot of SOO or fraction thereof
36、on the order and subjected to the following tests as described under “Test methodsIt: (a) Response time (b) Magnetic shielding (c) Vibration (d) Insulation resistance 4.3.3 Special tests.- Three of the meters of each part number representing the manufacturers contract or order, and samples selected
37、as often thereafter as the pro- curing activity deems advisable, shall be subjected to any or all of the tests listed below as described under “Test methodsIt: (a) Humidity resistance (b) Low temperature exposure (c) Mounting nuts (d) Mounting lugs 4.3.4 Rejection and retest.- 4.3.4.1 When tests are
38、 specified on a number of items that are selected as repre- sentative of a certain lot, and one or more of this number fails to meet the specified test(s), is determined. For operational reasons, Individual tests may be continued pending in- vestigation of a Sampling test failure, but the final acce
39、ptance of the product is contingent upon the Inspectors decision regarding the over-all conformance of the product to specification requirements. If investigation indicates that the defects may exist on items previously accepted, full particulars concerning the defect( s) found, including recommenda
40、tions for correction, shall be furnished to the procuring activity. acceptance of all items shall be withheld until the extent and cause of failure 4.3.4.2 Items which have been rejected may be reworked or replaced to correct the defects, and resubmitted for acceptance. cerning previous rejection an
41、d the action taken to correct the defects found in the . original shall be furnished the Inspector. Units rejected after retest shall not be resubmitted without the specific approval of the procuring activity. Before resuEmitting, full particulars con- ise specified, the meters shall be tested at ro
42、om temperature hall be tapped lightly in taking iction after vibration. r acceptance under contract ion with respect to I /-7 .- . - I .:;,Y.- ._ c. . Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-mlA-6752A( ASO ) . 4.5.2 Dmn 5n Voltage or current
43、sufficient to produoe mq taken and recoxuled, . Alter the pointer has come to rest, the steay d be taken and recorded. Thedamping factor shall be considered the rra deflection in angular degrees ta the difference between the mex3mwn marnent and the steady deflection in anguar degineea, 4.5.3 InsuLat
44、ion resistance.- The voltage 89 specified inpar$qh. 3lS Mounting lugsr- The ins.trument case shall be mounted face downward on the movable head of a suitable testing machbe with the diameter of the case in a horizontal plane in order that the mounting lugs receive no added support. pin shall be inse
45、rted through the hole in the mounting nut ad attached to the pull strap in the stationary head of the machine, each lug for a period of l minute. A suitable The specified load shall be applied to sr PRJPARATION FOR DELIVERY 5.3. 5.2 Application,- The requirements of Section 5 apply only to direct pu
46、rchases by or direct shipments to the Governmento MIL-P-6064, group VI, in a type II, class I container. Packaging,- The meter shall be packaged in accordance with Specification 5.3 Packing,- The interior packages shall be packed for domestic or overseas shipment, as specified, in accordance with ap
47、plicable requirements of Specification Mn-P-6Q64. I4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-5.4 Marking of shipments.- Interior packages and exterior shipping containers shall be marked in accordance with Standard MIL-STD-129. follows: Range
48、 Amperes -(As applicable) Round Square Flange Mounting, Flange 2-3/8 x 2-3/8 x 3/8 Inch Thick, AN Part No. AN3201- , (as applicable), Specification MIL-A-6752A. The nomenclature shall be as heter, Direct Current, Panel Mounted, Marked Amperes (Range of Inscription) or Voltmeter, Direct Current, Panel Mounted, Marked Volt (Range of Inscription) Range Volts - , (as applicable) Round Square Flange Mounting, Flange 2-3/8 x 2-3/8 x 3/8 Inch Thick, AN Part No. AN3203- ,
