1、Designation: B979 12Standard Specification forNon-Specular (NS) Surface Finish on Overhead AluminumElectrical Conductors1This standard is issued under the fixed designation B979; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers non-specular surface finisheson overhead aluminum electrical conductors. Overhead al
3、umi-num electrical conductors, when installed, typically have ashiny surface appearance. This “reflective” or “specular”surface can make a transmission line more noticeable inappearance against the background landscape. A factory treat-ment process of the outer surface of the aluminum wires canrende
4、r the surface finish into a dull, non-reflective, matte greyfinish. This non-reflective or “de-glared” surface finish allowsthe conductor to become less visible when observed from adistance and enables the transmission line to blend in with theskyline or landscape background.21.2 This specification
5、is intended, by means of diffusereflectance measurement, to establish a uniformity of conduc-tor finish which is acceptable to the user. Such a specificationwill furnish a basis for consistent manufacturing processcontrol.1.3 The values stated in inch-pound units are to be regardedas standard. The v
6、alues given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to e
7、stablish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 The following documents, in effect on the date ofmaterial purchase, form part of this specification to the extentreferenced herein:2.2 ASTM Standards:3
8、B354 Terminology Relating to Uninsulated Metallic Electri-cal Conductors3. Terminology3.1 For definitions of terms relating to conductors, refer todefinitions found in Terminology B354.3.2 Definitions:3.2.1 speculara shiny, reflective appearance.3.2.2 non-speculara matte, non-shiny appearance.3.2.3
9、de-glaredanother term for non-specular.3.2.4 diffuse reflectionreflection in which light energy isscattered in many directions by diffusion at or below thesurface.4. Ordering Information4.1 Orders for material under this specification shall includethe following information:4.1.1 Aluminum overhead el
10、ectrical conductor to have anon-specular, Type “NS” surface finish.4.1.2 Unless otherwise specified the default non-speculargray finish requirement shall have an average maximum diffusereflectivity of not more than 32 %.5. Equipment5.1 To measure diffuse reflectance, a portable reflectancemeter4shal
11、l be employed with search units “Y” or “T”,equipped with a green tristimulus filter.5.2 For calibration, use a matte gray reference standardhaving a diffuse reflection value between 23 and 29 %.1This test method is under the jurisdiction of ASTM Committee B01 onElectrical Conductors and is the direc
12、t responsibility of Subcommittee B01.02 onMethods of Test and Sampling Procedure.Current edition approved Oct. 15, 2012. Published January 2013. DOI: 10.1520/B0979-12.2The historical origin of this standard is based upon AA/ANSI Standard C7.69originally developed by theAluminumAssociation, Inc. and
13、adopted for recognitionas an American National Standard in 1975.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM websi
14、te.4The sole source of supply of the apparatus (Photovolt Reflectance Meter, ModelNo. 577 or 577A) known to the committee at this time is Photovolt Instruments,Inc. If you are aware of alternative suppliers, please provide this information toASTM International Headquarters. Your comments will receiv
15、e careful consider-ation at a meeting of the responsible technical committee,1which you may attend.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States16. Test Procedure6.1 Four test measurements shall be made on every1 000 000 ft (305 000
16、 m) or fraction thereof produced perorder, per conductor size, with no more than one measurementper reel. Test measurements may be made either on theconductor during processing or on samples approximately 15in. (380 mm) long removed from the reel. Care must be takento minimize surface marks and loos
17、e stranding due to samplehandling. Samples should be free of any foreign materials suchas oil, grease, dirt, and metal particles.6.2 A1316 in. (0.8125 in./20.64 mm) diameter apertureshould be used for measuring 397 500 cmil (200 mm2) areaconductors and larger. For smaller conductor, a14 in. (0.25in.
18、/6.35 mm), or38 in. (0.375 in./9.52 mm) aperture should beused.6.3 Prior to each diffuse reflectance measurement, the mea-suring instrument shall be calibrated against a matte grayreference standard having a diffuse reflection value between 23and 29 %. The instrument is to be checked against therefe
19、rence standard before and after each series of readings toensure reliability and reproducibility of results (see Explana-tory Note 1). Caution should be exercised that the search unitis not pointed towards brightly lighted areas during measure-ments.6.4 To allow for slight variations in conductor su
20、rface colorand contour, a minimum of three areas of the sample shall beevaluated. The maximum reflectance for each area is deter-mined by placing the conductors surface centered over theaperture of the measuring device and moving the samplelongitudinally back and forth to obtain the maximum reading.
21、The average of the three maximum readings so obtainedconstitutes the acceptance criterion for diffuse reflectivity ofthe sample.7. Requirements7.1 All four test measurements of the conductor outersurface shall have a matte, non-specular gray finish with anaverage maximum diffuse reflectivity of not
22、more than 32 %when determined by applying the equipment and test procedureoutlined by this specification.8. Retest8.1 If two or more of the four test measurements fail,samples from each reel shall be tested. The test on the sampletaken from each reel will now determine whether the reelpasses or fail
23、s to meet this specification.8.2 If only one of the test measurements fails, then anadditional four random measurements should be made. If oneor more of the additional four measurements fails the test, thensamples from each reel will now determine whether each reelpasses or fails to meet this specif
24、ication. If the additional fourmeasurements all pass, the test the conductor represented bythe original four measurements meets this specification.9. Keywords9.1 deglared; non-specular; overhead electrical conductorsEXPLANATORY NOTESNOTE 1The search unit is to be calibrated in the same orientationdi
25、rection that the search unit is used when measuring the reflectivity of theconductor samples. For example, if the search unit is to be used with lightpointing down on top of the sample, then the calibration procedure is to beconducted with the search unit pointing down onto the reflectancestandard.
26、The photocells inside the detection unit are thermally sensitiveand it is best to keep the unit in the same orientation from calibration tomeasurement.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Use
27、rs of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every
28、 five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technic
29、al committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken
30、, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).B979 122
