1、f MIL-I-7723 66 7777706 OLL15b67 O MIL-1-87923 1 June 1979 MILITARY SPECIFICATION INDICATOR, TORQUEMETER, AEU-l3/A This specification is approved for use by all Departments and Agencies of the Department of Defense. 1, SCOPE 1.1 Scope. This specification covers one type of engine 2. APPLICABLE DOCUM
2、ENTS 2.1 Issues of documents. The following documents, of the issue in effect on date of invitation for bids or request for proposal, form a part of this specification to the extent speci- fied herein. torquemeter indicator for turboprop engines. SPECIFICATIONS FEDERAL DD-G -4 5 1 QQ-S -7 6 3 P PP-B
3、-60 1 PPP-B-636 MILITARY MIL-P-116 MIL-C-675 MIL-E-5400 MIL-C-5541 - Glass, Plate, Sheet, Figured (Float, Flat, - Steel Bars, Shapes, and Forgings-Corrosion - Box, Wood, Cleated Plywood - Box, Shipping, Fiberboard Glazing, Corrugated, Mirrors and Other Uses) Resisting - Preservation-Packaging, Metho
4、ds of - Coating of Glass Optical Elements (Anti- - Electronic Equipment, Airborne, General - Chemical Films and Chemical Film Materials Reflection) Specification for for Aluminum and Aluminum Alloys Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of us
5、e in improving this document should be addressed to: Hq AFLC CASO/LODS, Federal Center, Battle Creek, MI 49016, by using the self-addressed Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document or by letter. FSC 6620 Provided by IHSNot for ResaleNo reprod
6、uction or networking permitted without license from IHS-,-,-MIL-1-87723 66 7777906 0145670 7 MIL-1-87923 MIL-S-7742 MIL-A-8625 MIL-B-27497 STANDARDS MILITARY MIL-STD-1 O0 MIL-STD-105 MIL-STD-129 MIL-STD-130 MIL-STD-143 MIL-STD-454 MIL-STD-4 6 1 MIL-STD-4 62 M IL-STD-704 MIL-STD-781 MIL-STD-785 MIL-S
7、TD-7 94 MIL-STD-81 O MIL-STD-889 MIL-STD-1186 MS21209 MS33558 MS33639B MS33678 - Screw Threads, Standard, Optimum Selected Series, General Specification for - Anodic Coatings, for Aluminum and Aluminum Alloys - Bearings, Jewel, Sapphire or Ruby, Synthetic - Engineering Drawing Practices - Sampling P
8、rocedures and Tables for Inspec- tion by Attributes - Marking for Shipment and Storage - Identification Marking of US Military Property - Standards and Specifications, Order of Precedence for the Selection of - Standard General Requirements for Electronic Equipment - Electromagnetic Inter fer ence C
9、haracter- istics Requirements for Equipment - Electromagnetic Interference Character- istics, Measurement of - Electric Power, Aircraft, Characteristics and Utilization of - Reliability Tests, Exponential Distribution - Reliability Program for Systems and Equip- ment Development and Production - Par
10、ts and Equipment, Procedures for Packaging and Packing of - Environmental Test Methods - Dissimilar Metals - Cushioning, Anchoring, Bracing, Blocking, and Waterproofing, with Appropriate Test Methods - Insert, Screw Thread, Coarse and Fine, Screw Locking, Helical Coil, Crest - Numerals and Letters,
11、Aircraft Instrument Dial, Standard Form of - Case, Instrument, Clamp Mounted, Aircraft - Connector, Receptacle, Electric, Integral Mounting 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I .MIL-I-7723 66 7777706 OL45671 7 MIL-1-87923 HANDBOOKS MIL
12、ITARY MIL-HDBK-275 - Guide for Selection of Lubricants, .Fluids and Compounds for use in Flight Vehicles and Components PUBLICATIONS STANDARDIZATION DOCUMENT S D-6 - Provisions Governing Qualification (Copies of specifications, standards, drawings, and publica- tions required by contractors in conne
13、ction with specific pro- curement functions should be obtained from the procuring activity or as directed by the contracting officer,) 3. REQUIREMENTS 3.1 Qualification. Indicators furnished under this specifi- cation shall be products which are qualified for listing on the applicable qualified prod
14、ucts list at the time set for opening of bids (see 4.4 and 6.6). Qualification must be accomplished within the provisions and requirements of SD-6. That document requires that tests shall be monitored by a Government repre- , sentative designated by the preparing activity or its authorized agent. Th
15、e test procedure shall be in accordance with this . specification. All tests required by the specification shall be successfully accomplished and documented. Certification of test results is required by the witnessing Government representative. 3.2 Selection of standards and specifications. Standard
16、s and specifications for necessary commodities and services not speci- fied herein shall be selected in accordance with MIL-STD-143, 3.3 Materials. Materials used in the manufacture of indica- tors shall be suitable for the purpose and shall conform to applicable Government specifications. Materials
17、 conforming to contractors specifications may be used provided such specifi- cations are approved by the Government and contain provisions for adequate tests. The use of the contractors specification will not constitute waiver of Government inspection, 3.3.1 Fungs-proof materials. Materials that are
18、 nutrients for fungi shall not be used where it is practical to avoid them, Where used and not hermetically sealed, they shall be treated with a fungicidal agent acceptable to the procuring activity, 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
19、MIL-1-87923 66 m 9999906 0145672 O m MIL-1-87923 However, if they are used in a hermeticallysealed enclosure, fungicidal treatment will not be necessary. 3.3.2 Metals. Metals shall be corrosion-resistant or suitably treated to resist corrosion due to fuels, salt spray, or atmospheric conditions like
20、ly to be met in storage or normal service. 3.3.3 Dissimilar metals. Unless suitably protected against electrolytic corrosion, dissimilar metals shall not be used in initmate contact with each other , Dissimilar metals are defined in MIL-STD-889. 3.3.4 Nonmagnetic materials. Nonmagnetic materials sha
21、ll be used for all parts of the indicators except where magnetic mate- riais are essential. 3.3.5 Corrosive fumes. Materials used in the construction of the indicators shall not produce corrosive or deleterious fumes under the test conditions specified herein. 3.3.6 Protective treatment. When materi
22、als are used in the construction of the indicators that are subject to deterioration when exposed to climatic and environmental conditions likely to occur during service usage, they shall be protected against such deterioration in a manner that will in no way prevent compliance with the requirements
23、 of this specification. The use of any protective coating that will crack, chip, or scale with age or extremes of climatic and environmental conditions shall be avo id ed . 3.4 Design and construction. 3.4.1 General. The indicator assembly shall be designed to measure the displacement between the pu
24、lse signals generated by an electromagnetic torquemeter pickup assembly, and to convert this displacement to provide indication of engine torque. 3.4.2 Construction. The indicator shall be so constructed that no parts will work loose in service. It shall be.built to withstand the strains, jars, vibr
25、ations, and other conditions incident to shipment, storage, installation, and service, Pivots, bearings, and gears shall not bind nor shake and shall be as nearly frictionless as possible. 3.4.3 Case, The case shall conform to figure 1 and shall provide a hermetically sealed enclosure for the intern
26、al mechanism of the indicator. The design of the case shall be such that the internal mechanism may be removed from the case, replaced, and the case resealed. This shall be accomplished 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-1-87923 bb
27、 W 77777Ob OLLt5b73 2 W . MIL-I -87 92 3 without the use of special tools and fixtures unless they are approved by the procuring activity. The hermetic- sealing shall . be so accomplished that the seal will not be dependent upon material which will be affected by the action of any atmosphere to whic
28、h the indicator may be subjected. 3.4.3.1 Filling medium. The filling medium shall be of at The filling medium least,98 percent purity, free of dust particles, and shall con- - (dewpoint -65OC) at the filling pressure. shall be either a mixture of 88 to 92 percent nitrogen and the remainder helium o
29、r 100 percent helium. The absolute pressure of the filling medium in the case shall be 12 to 14.7 psi. I tain not more than 0.006 milligram of water vapor per liter 3.4.3.2 Sealing. When a pressure of approximately zero psia is applied to the exterior of the indicator case, the leak rate shall not e
30、xceed 0.lO.micron cubic foot per hour when 10 percent helium is used in the filling medium and shall not exceed 1.0 micron cubic foot per hour when 100 percent helium is vsed as the filling medium. 3.4.4 Coverglass. The coverglass shall conform to DD-(3-451 (Type I, Class I, Quality 91) and be clear
31、, flat, and free from flaws that would interfere with the normal reading of the in- strument. The thickness of the coverglass shall be of the minimum practicable and entirely suitable for the purpose . NOTE: Glass in accordance with the above specification, type, and quality which has had an anti-re
32、flection coating applied in accordance with MIL-C-675 is acceptable. 3.4.4.1 Case to coverglass distance. The distance between the outer surface of the coverglass and the front edge of the case shall be the minimum practicable and sh,all not exceed 1/32 inch. 3.4.4.2 Dial to coverglass distance. The
33、 .distance between the indicator dial and the inside of the coverglass shall be th minimum practicable and shall not exceed 0.188 inch. 3.4.5 Visibility of dial. The pointer, nmerals, at least 1/3 of the shortest graduations in the range from -4,000 to be visible from any point within the frustum of
34、 a cone whose side makes an angle of 30 with a perpendicular to the dial and 27,000 in -1b and all other specified markings on the dial shall * whose small diameter is the aperture ef the case. 3.4.6 Dial marking. The dial shall be harked as shown in figure 2. Unless otherwise specified, all visible
35、 portions of the dial shall be lusterless black color no. 37038 of FED-STD-595 and all markings on the dial shall be lusterless 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- -_ MIL-1-87923 66 9999906 OLLI5674 4 M IL-1-87 92 3 I I r 6 Provided by
36、 IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- -. MIL-1-67723 66 9999906 0345675 6 MIL-1-87923 .4.8.l and 25 Major graduations Minor graduations Lett er ing ltX 10QO“ Sub-Dial Numerals: O, 2, 4 Major graduations “X 100“ I. U Height or length Main Dial Inch +0
37、.,015 Numerals: -2, O, +5, 10, 15, 20, O. 156 0.187 O. 125 t 0.125 O. 125 . 6, 8 O . O63 0.094 0.646 Width of line or graduation Inch +0.005 O . 025 -0 030 O . 025 0.025 O. 025 0.025 O. 025 - FIGURE 2. Dial and Pointers. , 7 Provided by IHSNot for ResaleNo reproduction or networking permitted withou
38、t license from IHS-,-,- MIL-1-87923 66 W 7777706 0345676 MIL-1-87 92 3 white color no. 37875 of FED-STD-595. All markings shall be durable to withstand usage encountered in service. The form of numerals and letters shall be in accordance with MS 33558. Numerals shall distinctly indicate the graduati
39、on to which each applies. If practicable, each numeral shall be placed so that the center of area of numeral(s) is on the radial line joining the appropriate graduation and the center of the dial. Any con- fusion resulting in doubt as to the graduation to which the numeral applies shall be cause for
40、 rejection. When several numerals are, used in one group, the space between the numerals shall be not less than 1/64 inch. 3.4.7 Dial fasteners. The dial shall be securely fastened to the frame of the mechanism in such a manfier that it will not loosen or turn when the indicator is vibrated. If scre
41、ws are used for attaching the dial, they shall be so located that they will not interfere with dial markings or prevent the markings from being located in the proper position. 3.4.8 Pointer. The pointers of the indicator shall be as light weight as pi-acticable, sufficiently rigid to prevent os- cil
42、lation under vibration and snall te firmly attached to the mechanism but also shall be readiiy adjustable. The pointers shall be finished lusterless white, color no. 37875 of FED-STD-595. 3.4.8.1 Pointer length. The tip of the large poir.ter shall overlap the longest scale graduations by one-third.
43、3.4.0 External adjustments. The following djustmants and/or switches shall be accessible on the rear O the case: (1) Cal “A1 adjustment single turn potentiometer, range -2900 in. lbs. to -4400 in. lbs., not to exceed a total adjustment range to 2050 in. lbs. (2) Cal B“ adjustment; single turn potent
44、iometer adjustment range of 36500 in. lbs. (3) Three position calibra- tion switch (Cal A, B, and RI. * range 24700 in. ibs. to 26800 in. lbs., not to exceed a total 3.4.9.1 Switch location. The adjustments and switch shall be permanently attached to the back of the indicator, shall be operab1.e usi
45、ng only a screwdriver, and shall be constructed and mounted on the indicator so as to preclude inadvertent movement of the adjustments or switch position during handling and normal use. 3.4.9.2 Indicator and transmitter matching. The two adjust- .merits and switch shall be sufficient for fitting the
46、 indicator to the characteristics of a particular transmitter. It must be possible to match the indicator to the torque transmitter of the engine having the characteriskicc detailed in para 3.4.10.1. . 8 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-
47、,-t MIL-I-879Z3 bb m 9999906 0345677 T m MIL-1-87923 3.4.10 Input signal. For flight usage, the input signal shall be obtained from a compatible engine mounted torquemeter pickup assembly, with interconnection between the pickup assem- bly and the indicator assembly accomplished in accordance with f
48、igure 3. The d.c. resistance of either signal source, i.e., either torquemeter pickup coil, is 2.5 I 0.5 ohms. At 9.2 KHz, its impedance is approximately 4.1 ohms. The characteristics of this signal are as shown in figure 4 and in table I. The indi- cator shall accept from the torquemeter transmitte
49、r a 2-phase signal whose peak-to-peak voltage is constant at 13,820 RPM. The voltage difference between the two phases shall not exceed 10 percent of the larger value and the phase difference shall vary linearly with torque. The relationship that exists in the transmitter between electrical degrees of phase displacement and torque is fixed for any particular transmitter but may vary f
