1、 INCH-POUND MIL-PRF-38715B w/AMENDMENT 14 January 2007 SUPERSEDING MIL-PRF-38715B 15 October 1996 PERFORMANCE SPECIFICATION INDICATOR, COMBUSTIBLE GAS AND OXYGEN This specification is approved for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Scope. This specificatio
2、n covers two types of indicators for measuring combustible gas and oxygen. 1.2 Classification. Indicators covered by this specification should be of the following types as specified (see 6.2). Type I Indicator, combustible gas and oxygen, without calibrator Type II Indicator, combustible gas and oxy
3、gen, with calibrator Comments, suggestions, or questions on this document should be addressed to: ASC/ENOI, 2530 Loop Road West, Wright-Patterson AFB 45433-7101 or emailed to Engineering.Standardswpafb.af.mil. Since contact information can change, you may want to verify the currency of this address
4、information using the ASSIST Online database at http:/assist.daps.dla.mil. AMSC N/A FSC 6665 DISTRIBUTION STATEMENT A. Approved for public release, distribution is unlimited. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-38715B w/AMENDMENT
5、1 2. APPLICABLE DOCUMENTS 2.1 General. The documents listed in this section are specified in sections 3, 4, or 5 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 h
6、as been made to ensure the completeness of this list, document users are cautioned that they must meet all specified requirements of documents cited in sections 3, 4 or 5 of this specification, whether or not they are listed. 2.2 Government documents. 2.2.1 Specifications, standards, and handbooks.
7、The following specifications, 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. COMMERCIAL ITEM DESCRIPTIONS A-A-59281 Cleaning Compound, Solvent Mixtures DE
8、PARTMENT OF DEFENSE SPECIFICATIONS MIL-DTL-5624 Turbine Fuel, Aviation, Grades JP-4 and JP-5 MIL-DTL-83133 Turbine Fuels, Aviation, Kerosene Types, NATO F-34 (JP-8), NATO F-35, and JP-8+100 MIL-P-87107 Propellant, High Density Synthetic Hydrocarbon Type, Grade JP-10 DEPARTMENT OF DEFENSE STANDARDS M
9、IL-STD-810 Environmental Engineering Considerations and Laboratory Tests (Copies of these documents are available online at http:/assist.daps.dla.mil/quicksearch/ or from the Standardization Document Order Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA 19111-5094.) 2.3 Non-Government public
10、ations. 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. NATIONAL FIRE PROTECTION ASSOCIATION NFPA 70 National Electrical Code 2 Provided by IHSNot for Resal
11、eNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-38715B w/AMENDMENT 1 (Copies of this document are available online at http:/www.nfpa.org or from the National Fire Protection Association, 1 Batterymarch Park, Quincy, MA, 02169-7471.) 2.4 Order of precedence. In the event
12、 of a conflict between the text of this document and the references cited herein, 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 3.1 First article. When specified
13、 (see 6.2), a sample shall be subjected to first article inspection in accordance with 4.2. 3.2 Materials. The contractor shall select the materials, but the materials shall be capable of meeting all of the operational and environmental requirements specified herein. Recycled, recovered, or environm
14、entally 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 costs. 3.2.1 Metals. Metals shall be of the corrosion-resistant type and/or be suitab
15、ly treated to resist corrosion during normal service life. Materials contained within hermetically sealed enclosures are considered to be suitably protected from corrosion. Requirements specified fungicidal and corrosion protective treatment, anodizing of aluminum alloy parts, and nickel plating of
16、steel parts are not applicable for parts within hermetically sealed instruments. Stainless steel parts, steel parts that have been nickel plated, and aluminum alloy parts that have been anodized, shall be further protected against corrosion if necessary. 3.2.2 Fungus-proof materials. Materials which
17、 are not nutrients for fungi shall be used to the greatest extent practicable. In cases where materials that are nutrients for fungi must be used, such materials shall be treated with a fungicidal agent. 3.2.3 Protective treatment. When materials are used in the construction of the indicator that ar
18、e subject to deterioration when exposed to climatic and environmental conditions likely 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 usage of any prote
19、ctive coating that will crack, chip, or scale with age or extremes of climatic and environmental conditions shall be avoided. 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-38715B w/AMENDMENT 1 3.2.4 Explosive resistance. The indicator sha
20、ll be constructed intrinsically safe for Class I, Division 1, Group A, B, C and D locations (as defined by National Fire Protection Association Code 70 Article 500). 3.3 Physical characteristics. 3.3.1 Weight. The total weight of the indicator, both types, including batteries shall not exceed 20 pou
21、nds. 3.3.2 Dimensions. The indicator shall not be larger than 2 feet in any dimension. 3.3.3 Controls. The indicator shall be provided with a control(s) for obtaining the initial zero setting of the indicator and shall have a control(s) for changing the sensitivity (ranges) of the indicator. When se
22、t, controls shall not be accidentally disturbed. Controls must be usable with cold weather gear gloves. 3.3.4 Display. The indicator shall show the chosen range of Lower Explosive Limit (LEL) on a display that is readable in full sunlight from a distance of no less than 70 inches. The display shall
23、show measured LEL percentages for the chosen gas and range on a scale. 3.3.5 Scale ranges. The scales shall be either digital or analog. The range of the combustible gas scale shall be 0 to 50 percent (%) LEL and 0 to 5% LEL. It shall consist of 50 scale divisions with figures at the 0, 10, 20, 30,
24、40, and 50% graduations. The 0 to 5% LEL scale shall use the same divisions as the 0 to 50% LEL scale with 1% corresponding to the 10% figure on the 0-50% scale, 2% corresponding to 20%, etc. The range of the oxygen scale shall be 025%. It shall consist of 25 equal scale divisions with figures at 0,
25、 5, 10, 15, 20 and 25% graduations. The scale division requirement applies only when analog scales are used. A switch shall be provided to change the scale of the dual range combustible gas scale from 050% LEL to the 05% LEL scale, or the indicator shall automatically switch scales. For digital indi
26、cators, the display shall be rounded to the nearest 0.1% with 0.05% rounding up. 3.3.6 Construction. The indicator shall be capable of meeting all of the performance requirements after exposure to normal handling, to include dropping from no more than 3 feet. 4 Provided by IHSNot for ResaleNo reprod
27、uction or networking permitted without license from IHS-,-,-MIL-PRF-38715B w/AMENDMENT 1 3.4 Performance characteristics. 3.4.1 Gas detection. The indicator shall detect explosive vapor or gases associated with fuel oils or gasoline (including leaded gasoline), alcohol vapors, and hydrogen in mixtur
28、es with air. For each of the following gases and/or vapors, the indicator shall automatically (within 5 seconds) provide the true percent LEL after the user sets the gas selector switch to the appropriate gas. a. Jet, rocket and reciprocating engine fuels: (1) JP-4 (MIL-DTL-5624) (2) JP-5 (MIL-DTL-5
29、624) (3) JP-8 (MIL-DTL-83133) (4) PF-1 (5) JP-10 (MIL-P-87107) (6) 4-Part Cleaner (A-A-59281) (7) Aviation gasoline 100-130 octane b. Ethyl alcohol c. Hydrogen d. Benzene e. Methane f. Hexane g. Pentane h. Heptane 3.4.2 Stability. The indicator shall display a stable reading of the selected gas with
30、 a variation of no more or less than 10% of full scale. 3.4.3 Ranges of detection. The combustible gas scale shall have a range of 05% and 050% Lower Explosive Limit (LEL) for the selected gas in any ambient temperature from 18 to 52 degrees Centigrade (C). The oxygen scale shall have a range of 025
31、% and shall be temperature compensated to measure oxygen in the range of 18 to 52 C. 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-38715B w/AMENDMENT 1 3.4.4 Accuracy. On the combustible scales, the indicated concentration expressed in pe
32、rcent of the LEL of any gas or vapor, shall not be less than the true concentration or exceed the true concentration by more than 10% of full scale for both the 05% LEL and 050% LEL scales. On the oxygen scale, the difference between indicated concentration and the true concentration shall not be gr
33、eater than plus or minus 1.5% oxygen when tested in the range compensated for temperature. 3.4.5 Alarm. The indicator shall include audible and visual alarm signals. The set point for the alarm signals shall be adjustable over the full scale ranges of the instrument. 3.4.6 Calibration. The indicator
34、 calibration reference shall be a standard gas (recommended by the manufacturer and approved by the Government). Calibration shall be achieved by adjusting an external or internal potentiometer(s) appropriately for the calibrating gas or gases. 3.4.7 Power supply. The indicator shall run on recharge
35、able batteries. The batteries shall remain fully operational for no less than 8 continuous hours. The batteries shall be commercially available from a minimum of two sources (may include the item manufacturer). The batteries shall be user replaceable. 3.5 Environmental conditions. 3.5.1 Temperature.
36、 The indicator shall be capable of satisfying all of the performance requirements after exposure to an operating temperature range of 18 to 52 C. 3.5.2 Temperature shock. The indicator shall be capable of satisfying all of the performance requirements after exposure to a temperature shock of 18 to 2
37、1 C. 3.5.3 Rain. The indicator shall be capable of satisfying all of the performance requirements during and after exposure to rain. 3.5.4 Humidity. The indicator shall be capable of satisfying all of the performance requirements after exposure to high humidity conditions. 3.5.5 Salt. The indicator
38、shall be capable of satisfying all of the performance requirements after exposure to a salt air environment. 6 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-38715B w/AMENDMENT 1 3.5.6 Vibration. The indicator shall be capable of satisfying
39、all of the performance requirements after exposure to vibration during transportation and mobilization. 4. VERIFICATION 4.1 Classification of inspections. The inspection requirements specified herein are classified as follows: a. First article inspection (see 4.2). b. Conformance inspection (see 4.3
40、). 4.2 First article inspection. First article inspection shall be performed on one complete indicator assembly when a first article sample is required (see 3.1). This inspection shall include the examination of 4.4 and the tests of 4.5.1 4.5.16 done in the order stated. When determined necessary by
41、 the Government, a separate indicator shall be used for the fungus test of 4.5.11. 4.3 Conformance inspection. Conformance inspection shall include the examination of 4.4 and the tests of 4.5.1 4.5.5. 4.4 Examination. Each indicator shall be examined for compliance with the requirements. Any redesig
42、n or modification of the contractors standard product to comply with specified requirements, or any necessary redesign or modification following failure to meet the specified requirements shall receive particular attention for adequacy and suitability. 4.4.1 Weight. The indicator shall be examined f
43、or compliance with the weight restriction of 20 pounds in accordance with 3.3.1. 4.4.2 Dimensions. The indicator shall be examined for compliance with the dimensional restriction of 2 feet in accordance with 3.3.2. 4.4.3 Controls. The indicator shall be visually examined for compliance with 3.3.3. 4
44、.4.4 Display. The indicator shall be visually examined for compliance with 3.3.4. 7 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-38715B w/AMENDMENT 1 4.4.5 Scale ranges. The indicator shall be visually examined for compliance with 3.3.5. 4
45、.5 Methods of inspection. 4.5.1 Response. The indicator shall respond to a 50% LEL methane-air mixture within 5 seconds at standard temperature. 4.5.2 Scale accuracy. The indicator shall be tested with 25% and 50% LEL mixtures (gases of 3.4.1) in air as well as with 15% oxygen in nitrogen mixture. T
46、he indicated concentration shall not be less than the true concentration or exceed the true by more than 10% of full scale. The oxygen detector shall be tested for compliance with 3.4.4. Finally, at the discretion of the Government inspector, the contractor may be required to demonstrate the satisfa
47、ctory operation of any indication. 4.5.3 Alarm. The alarm shall be set at a chosen percent LEL below that used in 4.5.2 and then tested for compliance with requirement 3.4.5 during a test for scale accuracy in 4.5.2. 4.5.4 Calibration. The indicator shall be calibrated with a standard gas and tested
48、 for scale accuracy (see 4.5.2). 4.5.5 Stability. On each range, the indicator shall be operated on fresh air for 15 minutes, and “zeroed“ by means of the proper controls. On each range, the indicator shall then be operated on a methane-air mixture of known concentration and identity for 3 consecuti
49、ve periods of 5 minutes each, while being quickly and accurately “zeroed“ again on fresh air before each period of 5 minutes. The variation in reading shall not be lower than the true concentration nor exceed the true concentration by more than 10 percent of full scale. 4.5.6 High temperature. The indicator shall be mounted in its normal operating position in a cham
