1、Designation:D516221Standard Practice forDiscontinuity(Holiday)Testing of Nonconductive ProtectiveCoating on Metallic Substrates1This standard is issued under the fixed designation D5162;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision
2、,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 practice covers procedures for determining discon-tinuities using two types of test equipment:1.1.1 Test
3、Method ALow Voltage Wet Sponge,and1.1.2 Test Method BHigh Voltage Spark Testers.1.2 This practice addresses metallic substrates.For concretesurfaces,refer to Practice D4787.1.3 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.4
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 establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 Thi
5、s international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(T
6、BT)Committee.2.Referenced Documents2.1 ASTM Standards:2D4787 Practice for Continuity Verification of Liquid orSheet Linings Applied to Concrete SubstratesD7091 Practice for Nondestructive Measurement of DryFilm Thickness of Nonmagnetic Coatings Applied toFerrous Metals and Nonmagnetic,Nonconductive
7、Coat-ings Applied to Non-Ferrous Metals3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 discontinuity,as used in this standard,na flaw,void,crack,thin spot,foreign inclusion,or contamination in thecoating film that significantly lowers the dielectric strength ofthe coating film;
8、a discontinuity may also be identified as aholiday or pinhole.3.1.2 holiday,as used in this standard,na term thatidentifies a discontinuity.3.1.3 holiday detector,as used in this standard,na devicethat locates discontinuities in a nonconductive coating filmapplied to an electrically conductive surfa
9、ce.3.1.4 pinhole,as used in this standard,na film defectcharacterized by small pore like flaws in the coating which,when extended entirely through the film,will appear as adiscontinuity;a pinhole in the finish coat may not appear as adiscontinuity.4.Significance and Use4.1 A coating/lining is applie
10、d to a metallic substrate toprevent corrosion or reduce product contamination,or both.The degree of coating continuity required is dictated by serviceconditions.Discontinuities in a coating/lining are frequentlyvery minute and may not be readily visible.This practiceprovides a procedure for electric
11、al detection of discontinuitiesin nonconductive coating systems.4.2 Electrical testing to determine the presence and numberof discontinuities in a coating/lining is performed on a non-conductive coating/lining applied to an electrically conductivesurface.The allowable number of discontinuities shoul
12、d bedetermined prior to conducting this test since the acceptablequantity of discontinuities will vary depending on filmthickness,design,and service conditions.4.3 The low voltage wet sponge test equipment is generallyused for detecting discontinuities in coatings/linings having atotal thickness of
13、0.5 mm(20 mil)or less.High voltage sparktest equipment is generally used for detecting discontinuities incoatings/linings having a total thickness of greater than 0.5 mm(20 mil).4.3.1 Coatings/linings less than 0.5 mm(20 mil)in thick-ness may be susceptible to damage if tested with high voltage1This
14、 practice is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.46 on Industrial Protective Coatings.Current edition approved Nov.1,2021.Published November 2021.Originallyapproved in 1991.Last previ
15、ous edition approved in 2015 as D5162 15.DOI:10.1520/D5162-21.2For 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 website.Copy
16、right ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally 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.1?spark testing equipment.However,coatings/linings greaterthan 0.25 mm(10 mil)and
