1、Designation:D709113Standard Practice forNondestructive Measurement of Dry Film Thickness ofNonmagnetic Coatings Applied to Ferrous Metals andNonmagnetic,Nonconductive Coatings Applied to Non-Ferrous Metals1This standard is issued under the fixed designation D7091;the number immediately following the
2、 designation indicates the year oforiginal adoption or,in the case 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.This standard has been approved for use by
3、agencies of the U.S.Department of Defense.1.Scope*1.1 This practice describes the use of magnetic and eddycurrent gages for dry film thickness measurement.This prac-tice is intended to supplement the manufacturers instructionsfor the manual operation of the gages and is not intended toreplace them.I
4、t includes definitions of key terms,referencedocuments,the significance and use of the practice,theadvantages and limitations of coating thickness gages,and adescription of test specimens.It describes the methods andrecommended frequency for verifying the accuracy of gagesand for adjusting the equip
5、ment and lists the reporting recom-mendations.1.2 These procedures are not applicable to coatings that willbe readily deformed under the load of the measuring gages/probes,as the gage probe must be placed directly on thecoating surface to obtain a reading.Provisions for measuringon soft or tacky coa
6、tings are described in 5.7.1.3 Coating thickness can be measured using a variety ofgages.These gages are categorized as“magnetic pull-off”and“electronic.”They use a sensing probe or magnet to measurethe gap(distance)between the base metal and the probe.Thismeasured distance is displayed as coating t
7、hickness by thegages.1.4 Coating thickness can vary widely across a surface.Asa result,obtaining single-point measurements may not accu-rately represent the actual coating system thickness.SSPC-PA2prescribes a frequency of coating thickness measurement basedon the size of the area coated.A frequency
8、 of measurement forcoated steel beams(girders)and coated test panels is alsoprovided in the appendices to SSPC-PA 2.The governingspecification is responsible for providing the user with theminimum and the maximum coating thickness for each layer,and for the total coating system.1.5 The values stated
9、 in inch-pound units are to be regardedas standard.No other units of measurement are included in thisstandard.1.6 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 a
10、nd health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D609 Practice for Preparation of Cold-Rolled Steel Panelsfor Testing Paint,Varnish,Conversion Coatings,andRelated Coating ProductsD823 Practices for Producing Films o
11、f Uniform Thicknessof Paint,Varnish,and Related Products on Test PanelsD1730 PracticesforPreparationof AluminumandAluminum-Alloy Surfaces for Painting2.2 SSPC Standard:3SSPC-PA 2 Procedure for Determining Conformance to DryCoating Thickness Requirements2.3 ISO Standard:4ISO 19840 Paints and varnishe
12、scorrosion protection ofsteelstructuresbyprotectivepaintsystemsMeasurement of,and acceptance criteria for,the thicknessof dry films on rough surfaces1This practice is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings,Materials,and Applications and is the direct responsibility
13、 ofSubcommittee D01.23 on Physical Properties of Applied Paint Films.Current edition approved Nov.1,2013.Published December 2013.Originallyapproved in 2005.Last previous edition approved in 2012 as D7091 12.DOI:10.1520/D7091-13.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcon
14、tact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from Society for Protective Coatings(SSPC),40 24th St.,6th Floor,Pittsburgh,PA 15222-4656,http:/www.sspc.org.4Available from Am
15、erican National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.Terminology3.1 Defin
16、itions of Terms Specific to This Standard:3.1.1 accuracy,nthe measure of the magnitude of errorbetween the result of a measurement and the true thickness ofthe item being measured.3.1.1.1 DiscussionAn accuracy statement predicts theability of a coating thickness gage to measure the true thicknessof a coating to be measured.Accuracy statements provide theperformance capability across the full functional measurementrange of the gage.Accuracy statements frequently include afixed portion that remain
