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
2、 database at https:/assist.dla.mil/. AMSC N/A FSC 5977 INCH-POUND MIL-DTL-8971F 16 September, 2013 SUPERSEDING MIL-DTL-8971E 22 August 2011 DETAIL SPECIFICATION ELECTRODES, GRAPHITE, SPECTROMETRIC GRADE Reactivated after 22 August 2011 and may be used for new and existing designs and acquisitions. T
3、his specification is approved for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Scope. This specification covers high-purity graphite disk and rod electrodes used in rotary disk electrode optical emission spectrometers for wear particle analysis through detection of
4、metallic elements in oils and other fluids. 1.2 Classification. The electrodes are of the following types as specified below (see 6.2), and will be identified by the following part or identifying numbers (PINs) (see 1.3 and 6.7): Electrode Type PIN Disk - Type I M8971-1 Rod - Type II M8971-2 Provide
5、d by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-8971F 2 1.3 Part or identifying number (PIN). The PIN to be used for electrodes acquired to this specification is created as follows: M 8971 - X Type: 1 - Type I - Disk electrode 2 - Type II - Rod elec
6、trode Specification number Denotes military specification 2. APPLICABLE DOCUMENTS 2.1 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 additi
7、onal information or as examples. While every effort has been made to ensure the completeness 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 Non-government
8、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. AMERICAN SOCIETY FOR QUALITY (ASQ) ASQ Z1.4 - Sampling Procedures and Tables for Inspection by
9、 Attributes (Copies of this document are available online at http:/www.asq.org/ or from American Society for Quality, 600 North Plankinton Avenue, Milwaukee, WI 53203.) ASTM INTERNATIONAL ASTM C559 - Standard Test Method for Bulk Density by Physical Measurements of Manufactured Carbon and Graphite A
10、rticles ASTM C651 - Standard Test Method for Flexural Strength of Manufactured Carbon and Graphite Articles Using Four-Point Loading at Room Temperature ASTM C1161 - Standard Test Method for Flexural Strength of Advanced Ceramics at Ambient Temperature Provided by IHSNot for ResaleNo reproduction or
11、 networking permitted without license from IHS-,-,-MIL-DTL-8971F 3 (Copies of these documents are available online at http:/www.astm.org/ or from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959.) INTERNATIONAL ORGANIZATION FOR STANDARDIZATION (ISO) ISO 1001
12、2 - Measurement management systems - Requirements for measurement processes and measuring equipment (Copies of this document are available online at http:/www.ansi.org/ or from American National Standards Institute, 25 West 43rd Street, 4th Floor, New York, NY 10036.) NATIONAL CONFERENCE OF STANDARD
13、S LABS (NCSL) NCSL Z540.3 - Requirements for the Calibration of Measuring and Test Equipment (Copies of this document are available online at http:/www.ncsli.org/ or from National Conference of Standards Labs, 1800 30th Street, Suite 305B, Boulder, CO 80301-1026.) 2.3 Order of precedence. Unless oth
14、erwise noted herein or in the contract, in the event 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 obtaine
15、d. 3. REQUIREMENTS 3.1 Qualification. Electrodes furnished under this specification shall be products that are authorized by the qualifying activity for listing on the applicable qualified products list (QPL) before contract award (see 4.4 and 6.3). 3.2 Material. Electrodes shall be made from high-p
16、urity spectrometric grade graphite and shall be as free as possible of the elements classified herein as impurities (see 3.8). 3.3 Electrode geometry and dimensions. The geometry and dimensions of the disk and rod electrodes described herein shall conform to figures 1 and 2 respectively. 3.3.1 Disk
17、electrodes. Disk electrodes shall be right circular cylinders having an outside diameter of 0.492 inch and a height (thickness) of 0.200 inch. They shall have a 0.125-inch diameter hole through the center that is concentric with the outer cylindrical surface. For tolerances and eccentricity between
18、the center hole and the outer cylindrical surface, see figure 1. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-8971F 4 NOTES: 1. All dimensions are in inches. 2. The A datum is a reference axis located at the longitudinal centerline. FIGURE
19、 1. Dimensions of disk electrode. 3.3.2 Rod electrodes. Rod electrodes shall be true cylindrical forms, having a circular cross-section with a diameter of 0.242 inch. They shall be between 5.90 and 6.25 inches long. For tolerances and maximum bow allowable, see figure 2. Rod electrodes shall be capa
20、ble of passing freely through a 0.244-inch diameter hole. NOTE: 1. All dimensions are in inches. FIGURE 2. Dimensions of rod electrode. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-8971F 5 3.4 Mass. The mass of the electrodes shall be dete
21、rmined in accordance with 4.6.2.1. The mass of a disk electrode shall be not less than 0.918 grams (g). The mass of a rod electrode shall be not less than 7.18 g. 3.5 Density. The density of the electrode stock shall be determined in accordance with 4.6.2.2. The density shall be not less than 1.60 g
22、rams per cubic centimeter (g/cm3). 3.6 Resistivity. The resistivity of the electrode material shall be determined in accordance with 4.6.2.3. The resistivity shall be 220 to 450 micro-ohm-inches (-inches). 3.7 Flexural strength. The flexural strength of the electrode material shall be determined in
23、accordance with 4.6.2.4. The flexural strength shall be 2,200 to 7,300 pounds per square inch (psi). 3.8 Electrode impurities. The following elements are classified as impurities for electrodes covered by this specification: iron (Fe), silver (Ag), molybdenum (Mo), aluminum (Al), chromium (Cr), nick
24、el (Ni), silicon (Si), copper (Cu), magnesium (Mg), sodium (Na), lead (Pb), tin (Sn), titanium (Ti), boron (B) and zinc (Zn). The amount of impurities in electrodes shall be determined in accordance with 4.6.2.5. The amount of each impurity element in electrodes shall be not more than one part per m
25、illion (ppm). The combined amount of all impurity elements in electrodes shall be not more than six ppm. 3.9 Electrode accuracy and repeatability. The accuracy and repeatability characteristics of electrodes shall be determined in accordance with 4.6.2.6. Electrode accuracy characteristics shall con
26、form to the criteria of table I. Electrode repeatability characteristics shall conform to the criteria of table II. For identification and test purposes, new electrodes being tested for qualification or conformance determination shall be identified as candidate electrodes, and reference electrodes s
27、hall refer to electrodes that have previously been tested and approved for government use, and are being used to facilitate the testing of candidate electrodes. 3.10 Workmanship. The electrodes shall be uniform in quality and free from all defects (such as pits, chips, flat spots, cracks, fractures,
28、 and spalling), which may affect their serviceability and appearance (see 4.6.1). 3.11 Cleanliness. Disk electrodes, rod electrodes, non-electrode test specimens (see 4.3.1) and containers supplied to the Government shall be free of non-carbon dust, dirt, machining debris or scrap, fingerprints, moi
29、sture, or other foreign matter that can be detected by visual examination and/or touch (see 4.6.1). Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-8971F 6 TABLE I. Electrode accuracy criteria. This procedure shall be used to determine if ele
30、ctrodes pass accuracy requirements. First, use the following formula to calculate the Accuracy Index (AI) for each element at each applicable concentration level for both the candidate and the reference electrodes (see 3.9 and 4.6.2.6): AI = X Y , Absolute value of ( X Y), where X is the mean of the
31、 test results of N analyses (normally 10) in ppm and Y is the elemental concentration in the oil calibration standard solution in ppm. Second, compare the AI value for the candidate electrodes to the corresponding value tabulated below. Third, if needed, statistically compare the AI values of the ca
32、ndidate and reference electrodes using a t-test (see 4.6.2.6b). If the candidate electrodes AI value is equal to or less than the tabulated value, or if the statistical comparison between the AI values indicates the candidate electrodes are equal to or better than the reference electrodes, then the
33、candidate electrodes pass the accuracy requirement for an element at a specific concentration. To pass the accuracy requirements for this specification, the candidate electrodes must pass the accuracy requirements for all elements at all applicable concentrations. Y Fe Ag & Mo Al, Cr, Ni, & Si Cu &
34、Mg Na Pb Sn Ti B Zn 5 1.50 1.50 1.20 1.61 2.59 1.98 1.98 1.30 1.30 1.99 30 5.23 5.23 3.33 5.91 11.60 4.47 4.47 3.93 3.93 8.15 100 16.00 16.00 9.65 18.20 37.10 12.20 12.20 11.70 11.70 25.60 300 46.70 46.70 27.80 53.50 110.00 34.30 34.30 33.90 33.90 75.60 500 77.50 N/A146.00 88.80 183.00 56.60 56.60 5
35、6.10 56.10 126.00 900 139.00 N/A N/A 159.00 328.00 101.00 N/A N/A 101.00 226.00 1 N/A = Not Applicable Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-8971F 7 TABLE II. Electrode repeatability criteria. This procedure shall be used to determi
36、ne if electrodes pass repeatability requirements. First, use the following formula to calculate the Repeatability Index (RI) for each element at each applicable concentration level for both the candidate and the reference electrodes (see 3.9 and 4.6.2.6): RI = ( ) ( )( )( )1NNN22 iiXXwhere N is the
37、number of analyses (normally 10), X i 2is the sum of the squares of the test results in ppm of the N analyses, and (X i)2is the square of the sum of the same test results. Second, compare the RI value for the candidate electrodes to the corresponding tabulated value. Third, if needed, statistically
38、compare the RI values of the candidate and reference electrodes using an F-test (see 4.6.2.6b). If the candidate electrodes RI value is equal to or less than the tabulated value, or if the statistical comparison between the RI values indicates the candidate electrodes are equal to or better than the
39、 reference electrodes, the candidate electrodes pass the repeatability requirements for an element at a specific concentration. To pass repeatability requirements for this specification, the candidate electrodes must pass the repeatability requirements for all elements at all applicable concentratio
40、ns. Y Fe Ag & Mo Al, Cr, Ni, & Si Cu & Mg Na Pb Sn Ti B Zn 5 0.56 0.64 0.56 0.56 0.64 0.95 1.04 0.58 0.58 0.78 30 1.58 2.45 1.58 1.58 2.45 2.01 2.06 1.87 1.87 3.63 100 5.03 8.02 5.03 5.03 8.02 6.07 6.08 6.02 6.02 12.00 300 24.00 24.00 15.00 27.00 48.00 18.00 18.00 18.00 18.00 36.00 500 40.00 N/A1 25
41、.00 45.00 80.00 30.00 30.00 30.00 30.00 60.00 900 72.00 N/A N/A 81.00 144.00 54.00 N/A N/A 54.00 108.00 1N/A = Not Applicable Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-8971F 8 4. VERIFICATION 4.1 Classification of inspections. The inspe
42、ction requirements specified herein are classified as follows: a. Qualification inspection (see 4.4). b. Conformance inspection (see 4.5). c. Retention of qualification inspection (see 4.7.1). 4.2 Inspection conditions. Gages and instruments used in qualification and conformance inspections shall be
43、 properly calibrated in accordance with NCSL Z540.3 or ISO 10012. Qualification inspections shall be performed in a draft-free room at a temperature of 68 to 86 F (20 to 30 C), a relative humidity of 30 to 80 percent, and a barometric pressure of 81.3 to 105 kilopascals (kPa) (24 to 31 inches of mer
44、cury). 4.3 Test specimens. The manufacturer shall provide the necessary specimens to perform all qualification and conformance testing. All specimens shall have been through the final purification process with their associated lot prior to testing, and conform to the following: a. Disk electrode spe
45、cimens shall be in accordance with 3.3.1 and figure 1. b. Rod electrode specimens shall be in accordance with 3.3.2 and figure 2. c. Non-electrode test specimens shall be in accordance with 4.3.1. 4.3.1. Non-electrode test specimens. A non-electrode test specimen may be used in testing of specified
46、requirements (see table III). When a non-electrode test specimen is used, the specimens shall be machined from the same batch of electrode raw stock used to manufacture the lot of electrodes being inspected. In addition, the non-electrode test specimens shall be processed through the final purificat
47、ion in the furnace with the electrodes being inspected. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-8971F 9 TABLE III. Qualification inspections. Inspections Requirement paragraph Verification paragraph Quantity of disk electrodes Quantit
48、y of rod electrodes Group A: Material1Workmanship Cleanliness 3.2 3.10 3.11 4.6.1 4.6.1 4.6.1 - 20 20 - 20 20 Group B: Dimensions Mass Density2 Resistivity2 3.3 3.4 3.5 3.6 4.6.1 4.6.2.1 4.6.2.2 4.6.2.3 20 20 20 - 20 20 20 - Group C: Flexural strength2Impurities Accuracy and repeatability 3.7 3.8 3.
49、9 4.6.2.4 4.6.2.5 4.6.2.6 - 40 500 - 40 50 1The Group A material inspection consists of an examination of the purity certification for the raw stock material used to manufacture the electrodes (see 3.2). 2Designates inspections that may have a non-electrode test specimen requirement (see 4.3.1). When choosing to use a non-electrode t
