1、AMSC N/A FSC 6645 DETAIL SPECIFICATION METER, TIME TOTALIZING This specification is approved for use by all Departments and Agencies of the Department of Defense. Reactivated after 19 October 2012 and may be used for new and existing designs and acquisitions. 1. SCOPE 1.1 Scope. This specification c
2、overs the general requirements for hermetically sealed, time totalizing meters. 1.2 Classification. The meters covered by this specification are of the types specified in the applicable specification sheets. 2. APPLICABLE DOCUMENTS 2.1 General. The documents listed in this section are specified in s
3、ections 3 or 4 of this specification. This section does not include documents cited in the other sections of this specification or recommended for additional information or as examples. While every effort has been made to ensure the completeness of this list, document users are cautioned that they m
4、ust meet all specified requirements of documents cited in sections 3 or 4 of this specification, whether or not they are listed. 2.2 Government documents. 2.2.1 Specifications, standards and handbooks. The following specifications, standards and handbooks form a part of this document to the extent s
5、pecified herein. Unless otherwise specified, the issues of these documents are those cited in the solicitation or contract.MIL-DTL-7793G 19 October 2012 SUPERSEDING MIL-M-7793F 15 September 1983 Comments, suggestions, or questions on this document should be addressed to the Naval Air Systems Command
6、, (Commander, Naval Air Warfare Center Aircraft Division, Code 4L8000B120-3, Highway 547, Lakehurst, NJ 08733-5100) or emailed to michael.sikoranavy.mil. Since contact information can change, you may want to verify the currency of this address information using the ASSIST Online database at https:/a
7、ssist.dla.mil. INCH-POUNDProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-7793G 2 DEPARTMENT OF DEFENSE SPECIFICATIONS MIL-DTL-5541 - Chemical Conversion Coatings on Aluminum and Aluminum Alloys MIL-A-8625 - Anodic Coatings for Aluminum and Al
8、uminum Alloys (See ASSIST database for list of specification sheets.) DEPARTMENT OF DEFENSE STANDARDS MIL-STD-130 - Identification Marking of U.S. Military Property MIL-STD-202 - Electronic and Electrical Component Parts MIL-STD-461 - Requirements for the Control of Electromagnetic Interference Char
9、acteristics of Subsystems and Equipment MIL-STD-889 - Dissimilar Metals MIL-STD-1285 - Marking of Electrical and Electronic Parts (Copies of these documents are available online at https:/assist.dla.mil/quicksearch/ or from the Standardization Document Order Desk, 700 Robbins Avenue, Building 4D, Ph
10、iladelphia, PA 19111-5094.) 2.3 Non-Government publications. The following documents form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are those cited in the solicitation or contract. ASTM INTERNATIONAL ASTM-B545 - Standard Specifi
11、cation for Electrodeposited Coatings of Tin ASTM-B633 - Standard Specification for Electrodeposited Coatings of Zinc on Iron and Steel (Copies of these documents are available from www.astm.org or ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959.) SAE INTERN
12、ATIONAL SAE AMS-QQ-N-290 - Nickel Plating (Electrodeposited) SAE AMS2404 - Plating, Electroless Nickel (Copies of these documents are available from www.sae.org or SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001.) Provided by IHSNot for ResaleNo reproduction or networking permit
13、ted without license from IHS-,-,-MIL-DTL-7793G 3 2.4 Order of precedence. Unless otherwise noted herein or in the contract, in the event of a conflict between the text of this document and the references cited herein (except for related specification sheets), the text of this document takes preceden
14、ce. Nothing in this document, however, supersedes applicable laws and regulations unless a specified exemption has been obtained. 3. REQUIREMENTS 3.1 Specification sheets. The individual item requirements shall be as specified herein and in accordance with the applicable specification sheet. In the
15、event of any conflict between the requirements of this specification and the specification sheet, the latter shall govern. 3.2 Qualification. Meters furnished under this specification shall be products that are authorized by the qualifying activity for listing on the applicable qualified products li
16、st before contract award (see 4.2 and 6.3). 3.3 Materials and components. The materials and components shall conform to applicable specifications and standards required herein or in detail specifications. If no specific materials or components are specified, the contractor shall select materials and
17、 components capable of meeting all of the operational and environmental requirements specified herein. 3.3.1 Non-magnetic materials. Non-magnetic materials shall be used for all parts except where magnetic materials are essential. 3.3.2 Metals. Metals used on the exterior of the meter shall be of th
18、e corrosion resistant type or suitably treated to resist corrosion due to fuels, salt spray or atmospheric conditions likely to be met in normal service or storage. 3.3.3 Dissimilar metals. Dissimilar metals as defined in MIL-STD-889 shall not be used in intimate contact with each other, unless suit
19、ably protected against electrolytic corrosion by means of protective coatings. 3.3.4 Aluminum alloy parts. Aluminum alloy parts shall be covered with an anodic film conforming to MIL-A-8625, except for internal components contained in a hermetically sealed enclosure or when any of the following cond
20、itions prevail: a. Small holes and case inserts. b. Aluminum alloys that do not anodize satisfactorily shall be coated with a chemical film in accordance with MIL-DTL-5541. c. To provide a paint base, chemical treatments in accordance with MIL-DTL-5541 may be used in lieu of anodizing. 3.3.5 Iron an
21、d steel parts. Iron and steel parts shall be nickel plated (per SAE AMS-QQ-N-290 or SAE AMS2404) or tin (per ASTM-B545) or zinc (per ASTM-B633) plated. Plating is Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-7793G 4 not required on parts m
22、ade from corrosion resisting steel or contained in a hermetically sealed enclosure. 3.4 Vacuum impregnation. Coils need not be impregnated when specified performance can be met without impregnation. 3.5 Protective treatment. Finishes and protective coatings which will crack, chip or scale during nor
23、mal service life, or are affected by extremes of atmospheric or environmental conditions shall not be used. 3.6 Fungus-proof materials. Materials that are nutrients for fungi shall not be used. 3.7 Design and construction. The meter shall be in accordance with the applicable specification sheet and
24、the requirements specified herein. In the event of any conflict between the requirements of this specification and the applicable specification sheet, the latter shall govern. It shall be built to withstand the strains, jars, vibrations and other conditions incident to shipping, storage, installatio
25、n and service. 3.7.1 Counting mechanism. The indicator counting mechanism shall have a digital readout as specified in the applicable specification sheets and shall be incapable of being reset. 3.7.2 Meter faceplate. The meter faceplate shall have a dull black finish. The hours numerals shall be whi
26、te on a dull black background. Meters with a 1/10thhour readout shall have the tenths place numeral colored red on a white background. The words “HOURS” or “HOURS AND TENTHS”, as applicable, shall appear on the faceplate, as may the manufacturers name or trademark. The meter shall have an operationa
27、l indicator visible through the faceplate that demonstrates the meter is operating when power is applied. 3.7.3 Enclosure. The case shall be in accordance with the applicable specification sheet and shall provide a hermetically sealed enclosure for the internal mechanism of the instrument. The herme
28、tic sealing shall be so accomplished that the seal will not be dependent upon materials which will be affected by the action of any atmosphere to which the meter may be subjected. 3.7.3.1 Finish. The case shall be finished in a durable, dull or semi-gloss black color. 3.7.4 Filling medium. The filli
29、ng medium shall be at least 98 percent purity and free of dust particles. The filling medium may not contain more than 0.006 milligram of water vapor per liter (dew point -65 C or -85 F maximum) at the filling pressure. The filling medium shall consist of 100 percent helium (preferred), a mixture of
30、 88 to 92 percent nitrogen and the remainder of helium or a mixture of inert noble gasses (such as argon and helium). The absolute pressure of the filling medium in the case shall be a minimum of one atmosphere. 3.7.5 Coils. The coils shall be properly insulated from the case and other grounded part
31、s. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-7793G 5 3.7.5.1 Coil temperature. The coil temperature rise shall be left to the discretion of the manufacturer, but shall be considered additive to the maximum operating temperature specifie
32、d herein. 3.7.6 Terminals. All terminals used for soldered connections shall be of the “hook-type” and shall be hot-tin dipped or tin plated in accordance with ASTM-B545. The terminals shall meet the solderability requirements of MIL-STD-202, Method 208, Test Method C. Each terminal shall accommodat
33、e one wire sized 22 AWG or smaller. 3.7.7 Operating position. The indicator shall be designed to operate in any position. 3.7.8 Interchangeability. All parts having the same manufacturers part number shall be directly and completely interchangeable with each other with respect to installation and pe
34、rformance. 3.7.9 Identification of product. Meters and assemblies and parts thereof shall be marked for identification in accordance with MIL-STD-130. 3.7.9.1 Nameplate. The following nameplate data shall appear on the outer surface of the enclosure: Manufacturers name or trademark Manufacturers mod
35、el number Nominal voltage and frequency (if applicable) Nominal power (watts) Military part number Coded date (Week and Year) in accordance with MIL-STD-1285 3.7.9.2 Use of AN or MIL designations. AN or MIL designations shall not be applied to a product, except for qualification test samples, nor re
36、ferenced to in correspondence, until notice of approval has been received from the activity responsible for qualification. 3.7.10 Mounting flange. Meter flanges shall be in accordance with the applicable specification sheet. Fixed flanges shall be tin-plated on the specified mount surface to provide
37、 a case ground for the meter. Tin-plate shall be 0.0002 inch minimum thickness and shall be in accordance with ASTM-B545. 3.8 Performance. The meter shall perform as specified in this section when tested in accordance with 4.4. 3.8.1 Examination of product. The meter shall conform to the dimensions,
38、 workmanship, marking and configuration requirements of this specification (see 4.4.1). 3.8.2 Operation. As evidenced by the operational indicator, the meter shall start and operate normally within 40 seconds after applying the specified voltage (see 4.4.2). (Note: This Provided by IHSNot for Resale
39、No reproduction or networking permitted without license from IHS-,-,-MIL-DTL-7793G 6 test verifies normal meter operation under short-term conditions. It is not a practical medium to measure the meters compliance with accuracy requirements.) 3.8.3 Power consumption. The average power consumption at
40、rated voltage shall be as specified on the applicable specification sheets (see 4.4.3). 3.8.4 Power supply tolerance. The meter shall be capable of withstanding the voltage and frequencies specified in 4.4.3 or the individual specification sheet. The meter shall meet the operational requirements of
41、3.8.2 after the test (see 4.4.4). 3.8.5 Insulation resistance. The insulation resistance between terminals and case shall exceed 100 megohms. The meter shall not be damaged by the test potential (see 4.4.5). 3.8.6 Dielectric strength. There shall be no damage, arcing, or current leakage in excess of
42、 1.0 milliampere (see 4.4.6). 3.8.7 Altitude. The meter shall operate normally at specified voltages and barometric pressure, with no evidence of damage after the test (see 4.4.7). 3.8.8 Thermal shock. The meter shall operate through a range of -65 C to +125 C unless otherwise specified in the appli
43、cable specification sheet. The meter shall not show any signs of electrical or mechanical damage after the test (see 4.4.8). 3.8.9 Moisture resistance. The meter shall meet the requirements of 3.8.2 after the test. There shall be no signs of moisture in the face of the meter nor signs of corrosion (
44、see 4.4.9). 3.8.10 Salt spray. The meter with mounting flange or removable faceplate attached shall meet the requirements of 3.8.2 after being subjected to the test of 4.4.10. There shall be no signs of moisture inside the face of the meter after the test. 3.8.11 Vibration. The meter shall meet the
45、requirements of 3.8.2 and shall show no evidence of mechanical damage and operate correctly during and after subjected to the vibration test as specified in 4.4.11. 3.8.12 Shock. The meter shall meet the requirements of 3.8.2 and shall show no evidence of mechanical damage and operate correctly afte
46、r subjected to the shock tests (see 4.4.12). 3.8.13 Hermetic seal. The meter shall operate satisfactorily after being subjected to the gross leak or fine leak test. The meter face shall show no evidence of the presence of moisture intrusion. Any leakage, as evidenced by bubbles, is considered a fail
47、ure of the MIL-STD-202, Method 104, Test condition A, gross leak test (see 4.4.13.1). The leak rate shall be not greater than .01 micron ft 3/hr for the fine leak test (see 4.4.13.2). 3.8.14 Life accuracy. Unless otherwise specified, when tested in accordance with 4.4.14, the meters shall have the f
48、ollowing minimum accuracy: Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-7793G 7 a. 28 VDC meters 1.0% b. 60 Hz AC meters 0.1%c. 400 Hz AC meters 0.1% 3.8.15 Electromagnetic compatibility. The meter shall conform to the electromagnetic comp
49、atibility requirements CE102 and RE102 of MIL-STD-461 (see 4.4.15). 3.8.16 Terminal stress. Each terminal shall withstand a 4.5 pound (20.0 Newton) axial force without loosening or being damaged (see 4.4.16). 3.8.17 Low temperature storage. The meter shall meet the operational requirements of 3.7.2 during the last -50 C step of the test (see 4.4.17). 3.9 Workmanship. The meter, including all parts and acc
