1、Designation: B979 12 (Reapproved 2018)Standard 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
2、 of revision, the 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 condu
3、ctors. Overhead alumi-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 alumi
4、num wires canrender 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 T
5、his specification 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 regarded
6、as standard. The values 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
7、this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the D
8、ecision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 The following documents, in effect on the date ofmaterial purchase, form part of this specific
9、ation to the extentreferenced herein:2.2 ASTM Standards:3B354 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 appearan
10、ce.3.2.2 non-speculara matte, non-shiny appearance.3.2.3 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 in
11、cludethe following information:4.1.1 Aluminum overhead electrical 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 meas
12、ure diffuse reflectance, a portable reflectancemeter4shall be employed with search units “Y” or “T,”equipped with a green tristimulus filter.1This test method is under the jurisdiction of ASTM Committee B01 onElectrical Conductors and is the direct responsibility of Subcommittee B01.02 onMethods of
13、Test and Sampling Procedure.Current edition approved March 1, 2018. Published March 2018. Originallyapproved in 2012. Last previous edition approved in 2012 as B979 12. DOI:10.1520/B0979-12R18.2The historical origin of this standard is based upon AA/ANSI Standard C7.69originally developed by theAlum
14、inumAssociation, Inc. and 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 Sum
15、mary page onthe ASTM website.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.
16、 Your comments will receive 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 StatesThis international standard was developed in accordance with i
17、nternationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.15.2 For calibration, use a matte gray refere
18、nce standardhaving a diffuse reflection value between 23 and 29 %.6. Test Procedure6.1 Four test measurements shall be made on every1 000 000 ft (305 000 m) or fraction thereof produced perorder, per conductor size, with no more than one measurementper reel. Test measurements may be made either on t
19、heconductor during processing or on samples approximately 15in. (380 mm) long removed from the reel. Care must be takento minimize surface marks and loose stranding due to samplehandling. Samples should be free of any foreign materials suchas oil, grease, dirt, and metal particles.6.2 A1316 in. (0.8
20、125 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./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 b
21、e calibrated against a matte grayreference standard having a diffuse reflection value between 23and 29 %. The instrument is to be checked against thereference standard before and after each series of readings toensure reliability and reproducibility of results (see Explana-tory Note 1). Caution shou
22、ld be exercised that the search unitis not pointed towards brightly lighted areas during measure-ments.6.4 To allow for slight variations in conductor surface colorand contour, a minimum of three areas of the sample shall beevaluated. The maximum reflectance for each area is deter-mined by placing t
23、he conductors surface centered over theaperture of the measuring device and moving the samplelongitudinally back and forth to obtain the maximum reading.The average of the three maximum readings so obtainedconstitutes the acceptance criterion for diffuse reflectivity ofthe sample.7. Requirements7.1
24、All four test measurements of the conductor outersurface shall have a matte, non-specular gray finish with anaverage maximum diffuse reflectivity of not 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 te
25、st measurements fail,samples from each reel shall be tested. The test on the sampletaken from each reel will now determine whether the reelpasses or fails to meet this specification.8.2 If only one of the test measurements fails, then anadditional four random measurements should be made. If oneor mo
26、re of the additional four measurements fails the test, thensamples from each reel will now determine whether each reelpasses or fails to meet this specification. If the additional fourmeasurements all pass, the test the conductor represented bythe original four measurements meets this specification.
27、9. Keywords9.1 deglared; non-specular; overhead electrical conductorsEXPLANATORY NOTESNOTE 1The search unit is to be calibrated in the same orientationdirection that the search unit is used when measuring the reflectivity of theconductor samples. For example, if the search unit is to be used with li
28、ghtpointing down on top of the sample, then the calibration procedure is to beconducted with the search unit pointing down onto the reflectancestandard. The photocells inside the detection unit are thermally sensitiveand it is best to keep the unit in the same orientation from calibration tomeasurem
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30、 are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional sta
31、ndardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical 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 Com
32、mittee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddr
33、ess 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 Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 12 (2018)2
