1、Comments, suggestions, or questions on this document should be addressed to DLA Aviation VEB, 8000 Jefferson Davis Highway, Richmond, VA 23297-5616 or e-mailed to STDZNMGTdla.mil. Since contact information can change, you may want to verify the currency of this address information using the ASSIST d
2、atabase at https:/assist.dla.mil. AMSC N/A FSC 6685 INCH-POUND MIL-DTL-7990D 15 August 2012 SUPERSEDING MIL-DTL-7990C 20 September 2007 DETAIL SPECIFICATION TRANSMITTER, TEMPERATURE, ELECTRICAL RESISTANCE, -70 TO +300C This specification is approved for use by all departments and agencies of the Dep
3、artment of Defense. 1. SCOPE 1.1 Scope. This specification covers electrical resistance temperature transmitters used in aircraft in conjunction with electrical resistance temperature indicators. 1.2 Classification. The electrical resistance temperature transmitters are of the sizes specified in tab
4、le I (see 6.2). TABLE I. Size - stem length and overall length. Size PIN Stem length (inches) Overall length (inches) 1 MS28034-1 1.875 3.500 2 MS28034-2 4.000 5.625 3 MS28034-3 0.325 2.125 4 MS28034-4 1.875 2.506 1.3 Part or identifying number (PIN). The PIN to be used for electrical resistance tem
5、perature bulbs acquired to this specification is created in accordance with MS28034.Reactivated after 20 September 2007 and may be used for new and existing designs and acquisitions. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-7990D 2 2.1
6、 General. The documents listed in this section are specified in sections 3 and 4 of this specification. This section does not include documents cited in other sections of this specification or recommended for additional information or as examples. While every effort has been made to ensure the compl
7、eteness of this list, document users are cautioned that they must meet all specified requirements of the documents cited in sections 3 and 4 of this specification, whether or not they are listed. 2.2 Government documents. 2.2.1 Specifications, standards, and handbooks. The following specifications,
8、standards, and handbooks 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 (see 6.2). DEPARTMENT OF DEFENSE SPECIFICATIONS MS28034 - Bulbs, Temperature, Electrical Resistance (-70 C t
9、o +300 C). DEPARTMENT OF DEFENSE STANDARDS MIL-STD-130 - Identification Marking of U.S. Military Property. MIL-STD-810 - Environmental Engineering Considerations and Laboratory Tests. MIL-STD-1916 - DoD Preferred Methods for Acceptance of Product. MIL-STD-31000 -Technical Data Packages. DEPARTMENT O
10、F DEFENSE HANDBOOKS MIL-HDBK-831 - Preparation of Test Reports. (Copies of these documents are available at https:/assist.dla.mil or from the Standardization Document Order Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA 19111-5094.) 2.2.2 Other government documents, drawings, and publicatio
11、ns. The following other government documents, drawings, and publications 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 (see 6.2). STANDARDIZATION DOCUMENTS SD-6 - Provisions Gover
12、ning Qualification. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-7990D 3 (Copies of these documents are available at https:/assist.dla.mil or from the Standardization Document Order Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA 1
13、9111-5094.) 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 (see 6.2). ASTM INTERNATIONAL ASTM B 117 - Standard Practice for
14、 Operating Salt Spray (Fog) Apparatus. (Copies of these documents are available at http:/www.astm.org/ or from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959.) 2.4 Order of precedence. Unless otherwise noted herein or in the contract, in the event of a con
15、flict between the text of this document and the references cited herein (except for related specification sheets), the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 3. REQUIREMENTS
16、3.1 Specification sheets. The individual item requirements shall be as specified herein and in accordance with MS28034. In the event of any conflict between the requirements of this specification and the specification sheet, the later shall govern. 3.2 Qualification. Transmitters furnished under thi
17、s specification shall be products that are authorized by the qualifying activity for listing on the applicable qualified products list before contract award (see 4.3 and 6.3). 3.3 Components. The transmitter shall consist of a resistance element, a transmitter housing, an electrical connector, and a
18、 gasket. 3.4 Materials. Metals shall be corrosion resistant unless protected to resist corrosion during normal service life. The use of dissimilar metals, especially brass, copper, or steel in intimate metal-to-metal contact with aluminum alloy, shall be avoided where practicable. 3.4.1 Recycled, re
19、covered, or environmentally preferable materials. Recycled, recovered, or environmentally preferable materials should be used to the maximum extent possible, provided that the material meets or exceeds the operational and maintenance requirements, and promotes economically advantageous life cycle co
20、sts. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-7990D 4 3.4.2 Protective treatment. When materials are used in the construction of the transmitter that are subject to deterioration when exposed to climatic and environmental conditions li
21、kely to occur during service usage, they shall be protected against such deterioration in a manner that will in no way prevent compliance with the performance requirements of this specification. The use of any protective coating that will crack, chip, or scale with age or extremes of climate and env
22、ironmental conditions shall be avoided. 3.5 Design and construction. 3.5.1 Temperature range. The transmitter shall be designed to function satisfactorily throughout the temperature range of -70 C to 300 C. 3.5.2 Construction. The transmitter shall conform to MS28034. The transmitter shall be constr
23、ucted to withstand the normal strains of jars, vibrations, and other conditions incident to shipping, storage, installation, and service without failure. The stem of the transmitter shall be brazed (or otherwise attached, subject to the approval of the procuring activity) to the transmitter head to
24、prevent any leakage into the transmitter winding or electrical receptacle. 3.5.3 Resistance element. The resistance element of the transmitter shall be hermetically sealed in a metal well or stem. 3.5.4 Temperature resistance characteristics. The temperature resistance characteristics of the transmi
25、tter shall conform to the values in table II. TABLE II. Temperature resistance values. C Ohms resistance C Ohms resistance -70 68.27 0.50 60 112.28 0.50 -60 71.19 0.50 70 116.27 0.50 -50 74.24 0.40 80 120.36 0.50 -40 77.39 0.40 90 124.55 0.50 -30 80.56 0.40 100 128.85 0.50 -20 83.77 0.40 110 133.26
26、0.50 -10 87.04 0.40 120 137.78 0.60 0 90.38 0.40 130 142.40 0.60 10 93.80 0.40 140 147.11 0.60 20 97.31 0.40 150 151.91 0.60 30 100.91 0.40 200 177.95 1.00 40 104.60 0.40 250 208.00 1.00 50 108.39 0.40 300 242.70 1.50 3.5.5 Electrical connection. The transmitter shall be provided with a suitable ele
27、ctrical receptacle as shown on MS28034. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-7990D 5 3.5.6 Gasket. Each transmitter shall be provided with a gasket as specified in MS28034. 3.6 Interchangeability. All parts having the same manufact
28、urers part number shall be directly and completely interchangeable with each other with respect to installation and performance. Changes in manufacturers part numbers shall be governed by the drawing number requirements of MIL-STD-31000. 3.7 Weight. The weight of the transmitter shall not exceed 0.2
29、5 pound. 3.8 Identification. Equipment, assemblies, and parts shall be marked for identification in accordance with MIL-STD-130. 3.9 Workmanship. 3.9.1 General. The transmitter, including all parts and accessories, shall be constructed and finished in a thoroughly workmanlike manner. Particular atte
30、ntion shall be given to neatness and thoroughness of soldering, wiring, marking of parts and assemblies, and freedom of parts from burrs and sharp edges. 3.9.2 Cleaning. The transmitter shall be thoroughly cleaned of loose, spattered, or excess solder, metal chips, and other foreign material after f
31、inal assembly. Burrs and sharp edges, as well as resin flash that may crumble, shall be removed. 4. VERIFICATION 4.1 Classification of inspections. The inspection requirements specified herein are classified as follows: a. Qualification inspection (see 4.3). b. Conformance inspection (see 4.4). 4.2
32、Test conditions. 4.2.1 Standard atmospheric conditions. Whenever the pressure and temperature existing at the time of the test are not specified, it is understood that the test is to be made at atmospheric pressure (approximately 29.92 inches Hg) and at room temperature (approximately 25 C). When te
33、sts are made with atmospheric pressure or room temperature differing materially from the above values, proper allowance shall be made for the difference from the specified condition. 4.2.2 Vibration. A vibration stand shall be used which will vibrate at any desired frequency between 300 cycles per m
34、inute (cpm) and 3,000 cpm and shall subject the transmitter to a linear vibration of the amplitude specified herein. 4.2.3 Resistance values. Where practicable, the resistance values given for tests results shall be the averages of direct and reversed readings to eliminate thermoelectric potential e
35、rrors. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-7990D 6 4.2.4 Test voltage. Unless otherwise specified herein, a voltage of 1.5 volts DC (VDC) 0.2 VDC shall be applied across the transmitter for making resistance measurements. 4.3 Qual
36、ification inspection. The sample for qualification inspection shall be subjected to the examination and tests specified in 4.5. 4.3.1 Inspection samples. The qualification inspection samples shall consist of three transmitters. Samples shall be identified with the manufacturers part number and any a
37、dditional information required by the contracting official. 4.3.2 Inspection report. When inspections are conducted at a location other than a laboratory of the procuring activity, three copies of the inspection report shall be submitted to that activity. MIL-HDBK-831 may be used as guidance when pr
38、eparing the inspection report. 4.4 Conformance inspection. The conformance inspection of the transmitters shall consist of individual tests and sampling plan A or B inspections, as specified (see 6.2). 4.4.1 Conformance inspection lot. An inspection lot shall consist of all transmitters manufactured
39、 under essentially the same conditions and offered for inspection at one time. 4.4.2 Individual tests. Each production transmitter shall be subjected to the following tests: a. Examination of product (see 4.5.1). b. Transmitter adjustment (see 4.5.2). 4.4.3 Sampling plan A inspection. Sampling and i
40、nspection shall be in accordance with MIL-STD-1916 for verification level I. Sampling plan A inspection shall consist of the following tests: a. Individual tests (see 4.4.2). b. Transmitter resistance (see 4.5.3). c. Vibration endurance (see 4.5.4). d. Response time (see 4.5.5). e. Thermal conductiv
41、ity (see 4.5.6). f. Thermoelectric potential (see 4.5.7). g. Self-heating (see 4.5.8). 4.4.4 Sampling plan B inspection. Unless otherwise specified (see 6.2), two transmitters shall be selected at random from the first 15 transmitters produced on the contract or acquisition order. Each transmitter s
42、elected for sampling plan B inspection shall be subjected to the following tests: a. Sampling plan A tests (see 4.4.3). b. Low temperature exposure (see 4.5.9). Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-7990D 7 c. High temperature expos
43、ure (see 4.5.10). d. Vibration - high temperature (see 4.5.11). e. Humidity (see 4.5.12). f. Insulation leakage (see 4.5.13). g. Salt spray (see 4.5.14). h. Strength for MS28034-1, MS28034-2, and MS28034-4 transmitters only (see 4.5.16). i. Pressure test for MS28034-3 transmitters only (see 4.5.16).
44、 4.5 Test methods. 4.5.1 Examination of product. Each transmitter shall be inspected to determine compliance with the requirements specified herein with respect to materials, workmanship, and marking. 4.5.2 Transmitter adjustment. The resistance of the transmitter shall be measured at room temperatu
45、re. The transmitter shall be placed in an agitated liquid bath, or other suitable nongradient apparatus, to the top of the attaching threads for conducting this test. The measured resistance of the transmitter shall conform to the value given in table II. 4.5.3 Transmitter resistance. The resistance
46、 of each transmitter shall be measured at temperatures of -50 C 5 C, 0 C 5 C, 100 C 5 C, 200 C 5 C, and 300 C 5 C in an agitated liquid bath. If desired by the inspector, resistance measurements at any other points in table II may also be made. The measured resistance shall be within the tolerance s
47、pecified in table II for the exact temperature of the master. To determine the true resistance equivalent to the temperature of the master, interpolation of the values given in table II may be required. The transmitter shall be immersed in the agitated liquid baths to the top of the attaching thread
48、s for all resistance measurements. 4.5.4 Vibration endurance. 4.5.4.1 MS28034-1, MS28034-2, and MS28034-4. For the MS28034-1, MS28034-2, and MS28034-4 configurations, the transmitter shall be mounted by the attaching threads on a suitably designed vibration stand. For one half of the test, the linea
49、r vibration shall be applied perpendicular to the longitudinal axis of the transmitter and for the other half of the test the linear vibration shall be applied parallel to the longitudinal axis of the transmitter. The vibration test shall be conducted for 4 hours with a total amplitude of vibration between 0.030 inch and 0.032 inch.
