1、MIL-B-l7089A(Aer) 18 ri 1 -SurseldesPL-B-i7089(Aer) of U. March 1952 This specification has been approved by the Bureau of Aeronautics, hpartment of the NavJr 1. SCOPE AND CLASSIFICATICPJ 1.1 -.-This specification covers aneroid barometers which are for use by Navy Weather activities to measure atmo
2、spheric air pressure by movements of.an evacuated metal diaphragm or diaphragms for pressures in the range of 910 to 1060 millibars. 1.2 -.-This specification covers one tp of Barometer, designated m-448( )/UM. 2. APPLICABLE COGUWCNTS 2.1 The- following specifications, publications and standards of
3、the issue in effect on date of invita- tion for bids form a part of-this specification. SPTCIFICATIONS : Federa4 QQ-B-621 - Brass, Commercial Yell.ow, High-Copper-Yellow and Naval: castings QQ-B-691 - Bronze, castings Militarx MIL-R-900 - Rubber, Synthetic, Medium-soft, Nolded Sheet, and Strip (for
4、Airport Hatch and Watertight and Airtight Door Gaskets) MIL-E-2036 - Enclosures (For Non-rotatinf? Electrical Equipment) (Naval Shipboard Use) -MIL-P-6064 - Packaging of Light-weight Aircraft Accessories MILS-6872 - Soldering Process, General Spcifications for MIL-E-15090 - Enamel, Equipment, Liqht-
5、. 4.2.4 rom.-When reference is made to an error permitted in a test, this error shall be defined as the difference between the indications of Barometer “48 and the correctecl .indication f-t_he . -. . , standakdhrometer when data is taken from both instruments simultaneously; When taking the reading
6、 of Barometer ML-4.448.the. instrument may .be, tapped-lightly. Pressures at tesT-points shall.65 e80 . 1047 - lobo Q.00 961: - 1030 1030 - 106.7 4.2.6.1 Chane in Error between Test Foints.-The. errors asdetermined above shall not change in magnitude by more than 2 percent of the pressure ehanqe bet
7、ween any two consecutive test points. . 4.2.7 Movemsnt.-The movement of the indicatin5 hand shall be noted in all tests specified in Paraqaph 4.2. When the pressure is ckianged uniformly the indicating hand shall move uniformly. Irregular motion of the indicating hand shall ba cause for rejection of
8、 the instrivnent. 4.2 .% Position istrument is in a vertical position. ?he instrument shall then be rotated successively into positions 45O forward and backward from vertical ancl 45O right and left of vertical and indicatLons read in each position. Vertical readings shall be considered as those -ta
9、ken when the instrument is normally mounted against a vertical plane with the 1015 mill.ibar qraduation up The difference in indication from vertical readings shall not exceed 0.3 millibrs. L.2.9 Temmrature Cvcle Tnst,-The barometer shall be subjected- to a .temperature cycle test. The instrument sh
10、all. be maintained -atata temperattire of 160F *5O for a period of at least one (1) hour. It shall then be transferred in not more than five (5) minutes time to a- chamber in which the tempera- ture is -509, The instrument shall he maintained at this temperature- for riot less than one how. This cyc
11、le shall be repeated et least four (4) “Gimes. At the completion of these cycles, the instrp ment, shall be carefully examined. There shall be no evidence of damage to the instrument 4.2.10 Pressure Cvcle Test.-The barometer shall be subjected to a pressure of 500millibars. Lt shall be held at this
12、pressure for a period of one (1) hour and then the pressure increased to 1150 millibars for a .period of me. (1) hour. This test shall be repeated until a total of four (4) cycles have been mads. After test of this paragraph .the zero shift shall not exceed 0.5 millibars. 4J.11 Frictioq.-The baromet
13、er shall be held in hand and read, .without jarring or rotating, the instrument shall be slowly and carefully lowered thres (3) feet. There shall h-.a perceptible movement of the indicating hand. The barometer shall then be raised three (3) feet- There shall be a percep- tible movement of the indica
14、ting hand 4.2.12 Hvsteresis.-Vhen tested in accordance with the procedure of Paragraph 4.2.6, the differences in errors for corresponding test points for ascending and descending pressure shall not exceed 0.4 millibars. 4.2.13 Recalibration.-The .test specified in Paraqraph 4.2.6 shall be repea6ed.
15、The data obtained shall not differ from the original calibration test by more than 0.-5 millibars. 4.2.111 Temrxrrature Compensation. 4.24l.4.P FreDroduction SaIi?DbS.-UCCeSSiVe tests shall be conductedat a constant pressure within each of the followinng pressure. ranges: (a) 915mbs f, 5mb3 (b) 1COO
16、mbs i 25mbs (c) lO55mbs +- 5mbs Y, 8 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- . I ML-B-l7089A(Aer) At each pressure point,. ths.tenperature 3hall be changed from an ambient room temperature of 7OoF $59 to each of the following temperatures: .
17、 . (a) -200F *2oF (c) t1200F two directions of vibration shall lie in the plane of the barometer. 4.2.16.2 Rate of Change of Vibration Freauencies-The frequancy of applied vibration shall be varied uniformly at a rate of approximately 1 cycle per second per minute. 4.2.16.3 Amplitude of Applied Vibr
18、ation.-The double amplitude (total excursion) of the vibration table shall be in accordance with table VII. Taole VI1 Amplitude-frequency conditions Frequency of Double Amplitude vibration c .p.s. Horizontal Vertical Inch Inch 4 to 10 O ,125 O J25 10 to 33 .O60 .O60 11.2.16.4 Nintv-minute Test-The e
19、quipment shall be vibrated for at least 30 minutes in each of three directions specified in 4.2.16.1 (total of at least 90 minutes). The range of the applied frequencies shall be from 4 through 33 cycles per second. 4.2.17 Gun Blast Proof .-The barometer shall be constructed to withstand degree (1)
20、gun blast pfi.aof of Specif icationEaL-E-2036. 4.2.18 Performance Recheck.-Upon completion of the tests of Para,graphs 4.2.15, 4.2.16 and 4.2.17; the performance tests of Paragraphs 4.2.8, 4.2.11, 4.2.12 and 4.2.13 shall be repeated. 5. PRZPARATION FOR DELIVERY 5.1 Packadne and Packine;.-The equibme
21、nt shall be packapd and packed in accordance with Specifica- tion MIL-p-6064 Group II., The contract shall specify whether packing shall be- domestic or for overseas with Specification JBNt-106. shipment. Wtwn overseas shipment is specified the equipment shall be packed in boxes in accordance Provid
22、ed by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-B-17089A (her) 5.2 Markinq.-All shipmnts shhll be marked in accordance with MIL4T.E-129. 6. NOFES .“Not applicable. NOTICE: When Government drewings, specifications, or other data are used for any purpose
23、 other than in connection with a definitely rFated Government procurement operation, -the . . United-States Goverment thereby incurs na responsibility nor any obligation whatsoever; and the fact that the CIovernment mag have formulated, furnished, or any way supplied . otherwise as in any manner lic
24、ensing the holder or any other person or corporation, or conveying any rights or r&ission to manufechre, use, or sell any patented hirention that may in any way be related thereto. . the said drawings, spzifications, 01 other data is notto be regarded by implication or ! Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
