1、_ at the filling pressure. shall be 88 to 92 percent nitrogen and the remainder helium. the filling medium in the case shall be 12 to 14.7 psi. snail not be used except with prior approval of the procuring activity. The filling medium The absolute pressure of Other concentrations of helium 1 Letteri
2、ng PSL 3.4.2 .Pointer.- The pointer shall be in accordance with MS33585, except that it shall be such length that the tip will extend into the scale a distance equal to one- third to two-thirds the length of the shortest graduation. 3.4.2.1 Pointer finish.- The shaded portion of the pointer. shall b
3、e finished in white material, color No. 37875 of Federal Standard No. 595. Height or length Width of line (inch - +i/64) or graduation 1/8 .O25 d 2.4.3 Dial.- The dial shall conform to figure 1. A minimum diameter of 1-3/4 . inches shall be maintained across the outside ends of the graduations. . gr
4、aduation shall be located on the horizontal centerline at the left side of the dial. The 90-psi - -* -_ - 3.4.3.1 Dial markings The markings specified in table1sha.U be finished in color No. 37875 of Federal Stmdard No. 595. table I. The dimensions shall be as specified in TABLE I. Dial markings I -
5、3- Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-I-7087A 66 W 7777706 0326025 4 mL-I-7087A ELECTRIC ZERO REFERENCE MAR , 37038 of Federal Standard No. 595. Loca- 3.4.3.2 DiaL visibil-.- Portions of the minor grad;iations on the dial shall be vi
6、sible when viewed fmrn any position within the frustum of a cone the side of which intersects the outer edge of the cover glass and which makes an angle of 30 degrees with fhe perpendicular through the cen5er of the dial. 3.4.3.3 Dial to cover glass distance.- The distance between the indicator dial
7、 and the inside of the cover glass shall be the minimum practicable and shall not ex- ceed 0.125 inch. 3.4.4 Filler tube.- A tube or other facility for evacuating and filling the case shall be provided at the rear of the case and shall be recessed beneath the level of the back plate surface: If a tu
8、be is used, it shall be of suchlength as to permit three re- fillings of the case. Cover glass.- The cover glass shall be clear, flat, and free from flaws thct would interfere with the normal reading of the instrument. cover glass shall be the minimum practicable and entirely suitable for the purpos
9、e. 3.4.5 The thickness of the 3.4.6 Fasteners.- The dial shall be securely fastened to the frame of the mech- anism in such a manner that it will not loosen or turn when the indicator is vibrated. If screws are used for attaching the dial, they shall be so located that they will not interfere with d
10、ial markings or prevent the maykings from being Jnrated in the proper position. 3.4.7 Electrical zero reference mark.- The dial shall be provided with an elec- . trical zero reference mark on the scale portion equidistant in angular degrees between the first and last dial graduations. 3.4.8 Electric
11、al connector.- The indicator shall be provided with an electrical connector confoniing to MS33678, or equa1,and it shall be hermetically sealed. The con- nector shall have the polarizing key at the tcp, . 3.4.9 Electrical wiring.- The indicator external wiring shall be in accordance with figure 2, 3
12、.4.10 Indicator synchro.- The indicator synchro shall consist of a salient two-pole wound rotor used as the primary and shall be designed for 26v, 4OOf Hz, as required, single-phase power, with wye-connected stators 8s the secondaries, The stators shall be so wound that the amplitudes of the tnduced
13、 voltages measured between any two stator leads will vary approximately sinusoidally with the angular positions of the rotor. nearly frictionless as possible. Pivots, bearings, and gears shall not bind nor shake and shall be as 3.4.10.1 The synchro receiver used shall have electrical characteristics
14、 compat- ible with those Sefined ir- MIL-S-20708. 3.4 70.2 Secondary volt age. - any two secondsv Leads shll be 11.8 23 percent. The maximum open-circuit volt age measured between . - -5- U -=-=- Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-I-
15、7087A TRANSMITTER i IN D I CATO R RECE P T A C MS33678R- l4S-2P AS APPLICABLE O MS33678-14s- 2P OR 400 HZ _. FIGURE 2. Wiring diagram -6- Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-I-7087A 66 7777706 0326028 T O 50 . 100 150 200 MIL-I-7087A
16、- 1.5 1.5 1.5 1.5 1- 5 3.4.11 Voltage an2 frequency variations .- The indicator shall withstand voltage and frequency vai-iation frorc 22V to 30V and 380 Hz to 420 Hz, without exceeding the scale error ant frictior. tolerances (see 3.5.1 and 3.5.2). 3.4.12 Electromagnetic interference.- The indicato
17、r shall meet the radiated arid conducted electromagnetic interference requirements of MIL-STD-461 for class ID s?uipment. 3.4.13 Reliability program.- progrm. in accorSance wish MIL-STD-785. The contractor shall establish a reliability 3.4.13.1 Reliabilit .- The indicator shall have a minimum accept
18、able mean- tLrne-between-fadF) of 2,000 hours based upon a discrimination ratio.of - 1.5 - and. .a confidence factor of 90 percent. 3.4.14 Longevity.- The indicator shall have an operating life span of 3,000 hours. 3.5 Performance.- The indicator shall operate satisfactorily after subjection i to th
19、e following conditions: Temperatures - temperatures raging from -6!j0to+7i0 C Vibration - vibration of 2gs from 5 to 500 HZ TemperatLre-altitude - pressure altitude of 10G,000 feet at -55O C Thermal chock - eight cycles of alternate immerions in tap water at 85 22“ C and 5 22“ C Salt fog - exposure
20、to salt sea atmosphere for 48 hours without evidence of corrosion or deterioration 3.5.1 Tolerances.- The indicator shall operate within the tolerances specified in tables-II and III. 3.5.2 Friction error,- Friction error shall not exceed the tolerances specified in table III. 3.5.3 Position error.-
21、 Position error shall not exceed the tolerances speci- fied in table III. 3.5,.4 Dielectric strength.- The indicator shall withstand 20UV rms at a commercial freqcency for a period of 5 seconds. 3.5.5 llL. O A -. -0- Provided by IHSNot for ResaleNo reproduction or networking permitted without licens
22、e from IHS-,-,- MIL-I-70B7A 66 = 777q70b 0226030 B . - MIL-1-7 087A 3.12 _I_- 4 hours at 50“ C, i prs- curing activity. Wrap with PPP-C-843 prior to Place the packsged The above reqirener.ts 5.2 PacklnE, - Each indicator procured in accordance with this specification shd.1 r be packed level “B“ for
23、stock in compliance with MIL-S?D-734, mlecs otherwise vpsi- fled ir the contyact or order by the procuring activity. 0 u .- rap* - . .- Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- -. - ._ MIL-I-70B7A bb 7799906 032603b 9 5.3 Marking of shipments
24、.- Interior packages and exterior shipping containers The nomenclature shall shell be marked for shipment in accordance with MIL-STD-129. be as follows: IXDICATOR, PRESSURE, OIL, SYNCHRO, 2-INCH SIZE, 0-200 PSI, MS2801O-3 5.31 ReinsEectlon cate mrkings.- Reinspection date markings shall be in accord
25、ance with the instrcctions of the procuring activiCYy (see 6.2). 6, NOTES 6.1 Intended use.- The indicator:. covered by this specification -is intended for use in conjunction with the MS28005-3 oil pressure transmitter in indicating remote- ly the oll pressure in aircraft systems. 6.2 Ordering hata.
26、 - Procurement documents should specify the folbowing : (a) (b) (c) (a) Title, .number, and date of this specification. Information, if any, to be submitted with quelification samples (see 4.4.1). When sampling gsRn B tests will not be conducted (see 4.5.2.2). Levels of packaging and packing require
27、d, hni reinspection date markings (see section 5). 6.3 Qua5f.ication.- With respect to products requiring qualification, awards d2.l be me.$-? only for producka which are at the time set for opening of bids, qualified for inclugir? in the a?plicr&le Quditied Products List whether or not such product
28、s have actually beer. so listed b? that date, The attention of the suppliers is called to this requirement, and masufacturers are urged to arranged to have the products.that .L they propose to offer to the Federal Government tested for qualification in order that they may be eligible to be awarded c
29、ontracts or orders for the products covered by this specification, tical Systems Division, Wright-Patterson Air Force Base, Ohio 45433, and information pertainingzto qualification of products may be obtained from that activity, The activity responsible for the Qualified Products List is the Aeronau-
30、 f 6.4 Marginal indicia,- Asterisks are not used in this revision to identify changes with respect to previous issue due to the extensiveness of the changes. Cuitoians : Nsvy - As Air Force - 11 Army - EL Reviewer activities: Navy - AS Air Fcrce - 71 &my - EL Preparing activity : Air Force - 11 Pro3 ect No , 6620-0185 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
