1、Designation:D152415Standard Test Method forVisual Examination of Used Electrical Insulating Liquids inthe Field1This standard is issued under the fixed designation D1524;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of las
2、t 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 test method for visual examination is applicable toelectricalinsulatingliquidsthathavebeenusedintransformers,oil circuit
3、breakers,or other electrical apparatusas insulating or cooling media,or both.1.2 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 establish appro-priate safety and health practices and determine
4、 the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D1500 Test Method for ASTM Color of Petroleum Products(ASTM Color Scale)D2129 Test Method for Color of Clear ElectricalInsulatingLiquids(Platinum-Cobalt Scale)3.Summary of Test Method3.1 The conditio
5、n of the test specimen is estimated byobservation of cloudiness,foreign particles,or suspendedmatter in the sample by reflected light.4.Significance and Use4.1 By use of this test method and Test Methods D1500 orD2129 the color and condition of a test specimen of electricalinsulating liquid may be e
6、stimated during a field inspection,thus assisting in the decision as to whether or not the sampleshould be sent to a central laboratory for full evaluation.Cloudiness,particles of insulation,products of metal corrosion,or other undesirable suspended materials,as well as anyunusual change in color ma
7、y be detected.5.Apparatus5.1 Sample ContainerThe sample vessel from a colorcomparitor,or a container in which light can be projected fromthe bottom into the sample.5.2 LightA light source such as a pen light with a No.222bulb.5.3 ClothPhotographers focusing cloth.6.Procedure6.1 Tyndall Beam Examinat
8、ionProject a narrow focusedlight beam from the pen light upward through the samplecontainer,using the photographic focusing cloth to excludeextraneous light.Carefully examine the test specimen bymeans of this light.A test specimen of good insulating liquidwill appear clean and bright.Haziness or clo
9、udiness usuallydenotes moisture in suspension or sludge.If the dielectricstrength is satisfactory,the cloudiness may be caused byoxidation products,in which case the neutralization numberwill probably be high and the interfacial tension low.Particlesof metals,insulation,carbon,and other matter will
10、show upvery markedly by reflected light.Report the electrical insulat-ing liquid as failing the test if the appearance of any conditionother than clear and bright is observed.7.Report7.1 Report the following information:7.1.1 Type of insulating liquid,7.1.2 Pass or fail,and the description of any de
11、viation fromperfectly clear and bright,7.1.3 Evidence of sediment or free water,7.1.4 Approximate temperature of the liquid at the time thetest specimen was taken,and7.1.5 Approximate temperature of the liquid at time ofobservation,if other than at room temperature.8.Precision and Bias8.1 It is not
12、practical to specify the precision and bias of thistest method because this is a rapid field examination to screentest specimens for further testing.1This test method is under the jurisdiction of ASTM Committee D27 onElectrical Insulating Liquids and Gases and is the direct responsibility of Subcom-
13、mittee D27.07 on Physical Tests.Current edition approved Oct.1,2015.Published October 2015.Originallyapproved in 1968.Last previous edition approved in 2010 as D1524 94(2010).DOI:10.1520/D1524-15.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at se
14、rviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 8.2 An interlaboratory investigation was conducted in 1968to
15、 support this test method.The results of this investigationwere first reported in January 1969.39.Keywords9.1Tyndell beam effect;visual examinationASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard.Users of
16、 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 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 Headquarte
