1、Ll. -p7- %7- - MIL-G-7818 . 26 NOVEMBER ISSJ . MILITARY SPECIFICATION GAU, FUEI, QUANTITY, CAPACITOR TYPE, COMPENSATED, GENWAL SPECIFICATION FOR This specification was approved by the Departments of the Arq, the Navy, a General Specification for Inspectim d Plating; cadmium (Electrodeposited) Connec
2、tors; Eectricd. Drawings and Data Lists; Preparatia of (m Engines, Accessories ad Other Auxiliary miPrnent Decaconmias; Aircraft aiel; Aircraft Rirbine and Jet Engine, Interference Liinits and Tests; Aircraft Electrical Lubrication of Aircraft, Oeneral Spcification for Nut, Seif-Locking, Instrument
3、Hmnting Packaging and Packing of Aircraft Material in-Steel Packaging of Lightweight Aircraft Accessdes Plates, Information and Identification Screw Threads, Stambmd,Aemnautic Tubes, Electron, Cables, Coaxial and lkin-CondUctor, for Radio Cable (Hook-up Wire), Electric, Insulated Radio Grade Jp-3 ar
4、d Eectronic Equipueirt Shipping Containera Frequency and Instrument 1835 - /rit6 Licensed by Information Handling ServicesProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- 9Ob 1882858 852 w- MIL-C-7 818 (November 1951) t Air Force-Navy Aeronautical AN
5、-QQ-A-696 Anodic-Films; Corrosion-Protective (For) AN-E-19 AN-L-1 Luminescent Material; Fluorescent AN-M-13 nautical Equipment, Accessories, Parts, Materials and Supplies AN-P-13 AN-P-32 Plating; Zinc Aluminum Alloys Electronic Equipment; General Specification for Marking, Labeling and Tagging, Airc
6、raft, Aero- Preservation and Packaging; Parts and Equipment (eneral. Specification for) 2.1.2 Other Publications.- Air Force-Navy Aeronautical Bulletin No. lb3 Specifications and Standards; Use of 2.1.3 Drawings.- Military Standards (Sheet) M53396 Case - Standard Dimensions for 3-1/4 Inch Size Instr
7、ument Ah Force-Navy Aeronautical Standard Erawws ANhl.30 AND10398 Metals - Definition of Dissimilar - AND10401- AND10401i AmlOL12 Fitting - Synthetic Tank Single-Plane Plush and Case - Standard Dimensions for 2-3/4 Dial Instrument Pointers - Standard Design of Aircraft Instrument Case - 2-Inch Siae
8、instrument, Standard Dimensions for (Copies of specifications, standards, and drawings required by contractors in con- Recessed (without sump) nection with specific procurement functions,. should be obtained f9m the procuring agency or as directed by the contracting officer.) 3. RWUIREMENTS 3.1 Mate
9、rials.- 3.1.1 Protective Treatment.- When materials are used in the construcMon of the gage that are subject to deterioration when exposed to climatic and enviromental condi- tions likely to occur during service usage, they shall be protected against such deteriora- tion in a manner that will in no
10、way prevent compliance with the perfonance requirements of this specification. The use of any protective coating that nill crack, chip, or scale with age or extremes of climatic and environmental conditions shaU be avoided. Materials shall conform to applicable specifications as specified herein. Wh
11、en materials are used which are not specifically designated, they shall be entirely suitable for the purpose. The use of lightweight materials and weight-saving designs is a major consideration, and their use shall be investigated and exploited to the greatest possible extent. 3.1.3 Metals.- Metals
12、shall be of the corrosion-resisting type or suitably treated to resist com? in fuels, salt spray, or atmospheric conditions to which the gage will be subjected when in storage or during normal service use. 3.1.2 3.1.4 Dissimilar Metals.- Unless suitably protected against electrolytic corrosion, Diss
13、imiJar metals dissimilar metals shall not be used in intimate contact with each other. are defined by Drawing ANDi0398. 2 k 1836 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-7999906 1882859 799 I r. 1837 I MIL-G-7818 ._ - (November 1951) 3.1.5 Non
14、magnrtic Material.- Nonmagnetic material shall be used for al1 parts, except where Egnetic materials are essential. 3.1.6 Fungus-Proof Materials.- Materials which are not nutrients for fungi shall be used to the greatest extent practicable. Where materials that are nutrients for fungi must be used,
15、such materials shall be treated uith a fungicidal agent, as approved by the procuring agency. 3.1.7 Selection of Materials.- Specifications and standards for all nsterials, parts, and Government certification and approval of processes and equipment, which are not specifi- cally designated herein and
16、 which are necessary for the execution of this specification, shall be selected in accordance with ANA Bulletin No. Ily spaced. The end point of the calibration shall be the number of pounds obtained by multiplying the usable tank volume in gallons by a density of 7.216 poiinds per gallon. The scale
17、 end shall be tne last divisiori cciore the end point (for example, if tne weight of fUel at the end point is 4,480 lb and the ninor graduations represept 200 lb, the scale end will be the ninor graduation representing 4,400 lb). (d) 9 Provided by IHSNot for ResaleNo reproduction or networking permi
18、tted without license from IHS-,-,-MIL-G-7 818 (November 199) I 3.5.5.5.b Did Markings,- All markings shall be durable to withstand usage encoun- tered in service. The dials shall be marked as shown on figures 1, 2, and 3. The gradua- tion markings shall be linear within tO“20 of arc for indicators c
19、onforming to figures l and 3, and within +Oo3Ot for indicators conforming to fibwe 2. major graduation shall be identified by a single numeral. - Wherever practicable, each 3.505.59L.i Marking dimensions for the indicator dial shown on figure 3 shall be In accordance with the following table: - Heig
20、ht or Width of Line Inch f0.010 Inch ?0.005 Eaish Markings Length or Graduation Majierial or MAIN DIAL Numerals o. 180 O o 031 Total Fuel Quan. O a 140 0.025 Fuel Quan. (as applicable) 0.156 OD O31 Major Grad 0.250 0.031 Minor Grad o .i88 0.015 LBC-X- 0,100 0.015 Fluorescent Luminescent SUB-DIAL Num
21、erals 0.100 0.015 Circle Dia O o 906 0.015 Graduations 0.094 0.010 Fluorescent XlOO or 1000, as applicable 0.062 o. 019 Luniinescent Background of Dial - - Durable Dull Black 3.5.505eb.2 Fluorescent Luminescent Material.- Fluorescent luminescent material shall konform to Specification AN-L-1. 3.505.
22、6 Pointers.- Unless otherwise specified herein, pointers for the indicators shall conform t-Oh-8. oscillation under vibration. Pointers shall be light and sufficiently rigid to prevent They shall be firmly attached to the associated mechanism. Pointer Length.- The pointer length shall be such that t
23、he pointer tip 3.5.5.6.1 will extend into the scale a distance equal to 1/3 to 2/3 of the length of the shortest graduation. 3.6 Electrical Cable.- Hook-up wire and external unshielded connector cable shall be in accorce with Specification JAN-C-76. Specification JAN-C-17. action of the fuel shall b
24、e entirely suitable for the purpose intended. where the temperature may exceed 90C in compartments of the aircraft structure through which the electrical interconnecting cables will be routed, the cables shall be specially designed for high temperature use and shall be subject to approval of the pro
25、curing agency. Internal wiring shall be neat and accomplished in a manner that individual wires may be easily traced. practicable. Coaxial cable shall be in accordance with In applications Electrical cable used within the fuel tank and subject to the Wires shall be tied to the terminals prior to sol
26、dering where 3.6.1 Cable Length.- Accuracyand sensitivity of the gage shall not be adversely affected by increasing or decreasing the tank unit interconnecting cables within the limits of from 5 to 100 feet. 10 1844 I. 5 i .: Provided by IHSNot for ResaleNo reproduction or networking permitted witho
27、ut license from IHS-,-,-9999906 1882867 865 LjL. 2 9 -.I/ MIL-G-7 818 (November 199) 3.7 Electrical Connectors.- The electrical connectors used, with the exception of those required for the tank unit circuits, shal1,be in accordance with Specification MIL-C-5015, unless otherwise approved by the pro
28、curing agency. and other types of connectors or methods of connection used on the tank unit assembly shall be suitable for the purpose intended and shall be subject to approval by the pro- curing agency. unit assemby shall be polarized at each point of connection. Coaxial cable connectors . The conn
29、ectors provided for interconnecting externally the complete tank 3,8 Input Electrical Power.- The gage shall be designed to operate from a Up, 400-cycle, single-phase a-c poner supply. specific installations may be operated from a 28V d-c power source subject to approval of the procuring agency. Tra
30、nsfer relays which may be required for 3.9 Damping.- Sufficient damping shall be provided in the gage assembly to elimi- nate excessive oscillation and provide steady indication of the pointer. Gages employing sensitive type indicators shall be designed to provide practically “dead-beat“ operation.
31、3.10 Calibration Adjustment.- Means shall be provided for adjusting the electrical circuit for range and calibration of the indicator. shall be such that a change in the full adjustment does not appreciably affect the posi- tion of the indicator pointer at the zero point. intermediate device and not
32、 in the tank units or indicator. The adjustments shall be of sufficient range to compensate for all manufacturing tolerances in the gage and the fuel tanks, and shall provide a sensitivity such that adjustments can be easily accomplished under service operations. The design shall be such that the co
33、mplete gage including the compensator can be accurately and easily checked when the gage is installed in the air- plane, by means of suitable test equipment. Adjustments of the indicator pointer The adjustments shall be located in the 3.11 Gage Failure Indication.- The gage shall be provided with a
34、readily acces- sible test button to indicate failure of the gage operation. depressed, shall cause the gage indication to decrease until the lower stop is reached. , When the button is released the gage indication shall return to normal. shall be designed to be mounted as a separate item and shal be
35、 subject to approval by the procuring agency. The test button, when The test button 3.12 Screw Threads.- Unless otherwise specified, the threads of all machine screws, 0.060 inch or larger in diameter, shall conform to Specification KCL-s-77)2. 3.13 Lubrication.- Lubrication shall be accomplished in
36、 accordance with Specifi- cation MIL-L-6880. unless otherwise approved by the procuring agency. Lubricants shall conform to applicable Government specifications, 3.ih Finishes and Protective Coatings.- 3.14.1 Finishes and protective coatings which will crack, chip, or scale during normal service lif
37、e or due to extremes of atmospheric conditions, shall not be used. 3.14.2 Aluminum-Alloy Parts.- Aluminum-alloy parts, where practicable, shall be covered with an anodic film conforming to Specification AN-QQ-A-696. 3.14.3 Steel Parts,- Steel parts shall be cadmium- or zinc-plated where practicable,
38、 in accordance with Specification QQ-P-416, type II or III, as applicable, and of a class that is adequate to achieve the degree of protection required, or Specification AN-P-32. 3.15 Identification of Product,- 3.15.1 Nameplate.- Nameplates conforring to Specification MIL-P-6906 shall be steusely a
39、ttached to each separately mounted unit of the gage and shall be legibly and permanently marked with the following information. provided on the nameplate shall be in accordance with Specification AN-M-13. The information marked in the spaces 11 . 1845 Provided by IHSNot for ResaleNo reproduction or
40、networking permitted without license from IHS-,-,-MIL-G-7818 (November 1951) 999Ob 1882868 7T1 = 3 INDICATOR (or Tank Unit, Power Unit, Amplifier, etc., GAGE, FUEL QUANTITY, CAPACITOR TYPE llsV, bOO-Cycle, Single-Thase, A-C, aecification MIL-G7818 Manufacturers Part No. Manufacturers Serial No. Stoc
41、k No. (USAF or Navy, as applicable) Contract or Order Yo. Manufacturer s Name or Trade-Mark U S Property as applicable) for Amp (Applies only to - Power Input Unit) 3.15.2 Use of AN or MIL Designations.- to a product, except for Qualification test samples, nor referred to in correspondence or sales
42、matter until notification has been received from the Aeronautical Standards Group that the product has been approved for aeronautical use, by both the Air Force and the bau of Aeronautics AN or MIL designations shall not be applied 3 .i6 Installation.- 3.16,l Installation Instructions.- For Navy pro
43、curement only, the contractor shall furnish with each instrument one printed copy of instructions, with illustrations and diagrams if necessary, covering the installation of the instrument. Prior to printing, two copies shall be furnished to the qualifying agency for approval. instructions shall be
44、arranged to require only one sheet of paper, either 8-1/2 by 11 inches or i7 by 11 inches. Whenever possible, the 3.16.2 Mounting Screws.- The contractor sha.1 furnish sufficient mounting screws for installing indcators conforming to figure 1. No. 6-32, NC-2 round head brass machine screws having a
45、durable dull black finish. shall be sufficient for mounting on a panel 3/16 inch thick. The indicator mounting screws shall be Lengths 3.16,3 Removable Spring Nuts.- For indicators conforming to figure 1, the contractor shall furnish a sufficient number of removable No. 6-32, NC-2 spring nuts to fit
46、 the morinting lugs of the indicator, of a type conforming to Specification MIL-N-3336. 3.16.4 of the basic circuit, point to point between all the basic components of the gage, insofar as practicable, shall be permanently affixed to the inside of the intermediate device or affixed to the mounting u
47、nit. The wiring of the tank unit assembly shall be shown in such a manner as to make the diagram applicable regardless of the number of tank units used. internal wiring diagram of each of the individual units of the fuel gage shall be permanently affixed on or within the unit where practicable. appl
48、ication, they shall conform to Specification EL-D-5548. Wiring Diagram.- A wiring diagram showing the external electrical connections An If decalcomanias are used for this 3.16.5 Envelope.- When applicable, an envelope furnished by the contractor shall be packaged with each indicator. mounting screw
49、s, and/or removable spring nuts as required. with the applicable portions of the following information: The envelope shall contain the installation instructions, Each envelope shall be marked It IMPORTANT INSTALLATION INSTRUCTIONS“ THIS ENVELOPE CONTAINS MOUNTING SCREWS, SPRING NTS AND 3.17 Workmanship.- j017.i General.- The gage, including all parts and accessories shall be constructed and finished in a thoroughly worhanlike manner. Particular atten
