ASTM_A_754_-_A_754M_-_11_2016.pdf

Designation:A754/A754M11(Reapproved 2016)Standard Test Method forCoating Weight(Mass)of Metallic Coatings on Steel byX-Ray Fluorescence1This standard is issued under the fixed designation A754/A754M;the number immediately following the designation indicates the yearof original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the use of X-ray fluorescence(XRF)for determining the coating weight(mass)of metalliccoatings on steel sheet.The test method is intended to be usedfor“on-line”measurements of coating on continuous produc-tion lines.1.2 This test method is applicable to the coatings covered bythe following ASTM specifications:A599/A599M,A623,A623M,A653/A653M,A792/A792M,A875/A875M,A879/A879M,A918,A924/A924M,A1046/A1046M,and A1063/A1063M.It may be applicable to other coatings,providing thatthe elemental nature of the coating and substrate are compat-ible with the technical aspects of XRF such as the absorptioncoefficient of the system,primary radiation,fluorescentradiation,type of detection.1.3 This test method includes the procedure for developinga single standard determination of coating weight(mass).1.4 This test method includes procedures for both X-raytube and isotope coating weight(mass)measuring instruments.1.5 The values stated in either inch-pound units or SI unitsare to be regarded separately as standard.Within the text,theSI units are shown in brackets.The values stated in eachsystem are not exact equivalents;therefore,each system shallbe used independently of the other.Combining values from thetwo systems may result in nonconformance with the specifi-cation.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 and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2A599/A599M Specification for Tin Mill Products,Electro-lytic Tin-Coated,Cold-Rolled SheetA623 Specification for Tin Mill Products,General Require-mentsA623M Specification for Tin Mill Products,General Re-quirements MetricA653/A653M Specification for Steel Sheet,Zinc-Coated(Galvanized)or Zinc-Iron Alloy-Coated(Galvannealed)by the Hot-Dip ProcessA792/A792M SpecificationforSteelSheet,55%Aluminum-Zinc Alloy-Coated by the Hot-Dip ProcessA875/A875M Specification for Steel Sheet,Zinc-5%Alu-minum Alloy-Coated by the Hot-Dip ProcessA879/A879M Specification for Steel Sheet,Zinc Coated bythe Electrolytic Process for Applications Requiring Des-ignation of the Coating Mass on Each SurfaceA902 Terminology Relating to Metallic Coated Steel Prod-uctsA918 Specification for Steel Sheet,Zinc-Nickel AlloyCoated by the Electrolytic Process for Applications Re-quiring Designation of the Coating Mass on Each SurfaceA924/A924M Specification for General Requirements forSteel Sheet,Metallic-Coated by the Hot-Dip ProcessA1046/A1046M Specification for Steel Sheet,Zinc-Aluminum-MagnesiumAlloy-Coated by the Hot-Dip Pro-cessA1063/A1063M Specification for Steel Sheet,Twin-RollCast,Zinc-Coated(Galvanized)by the Hot-Dip Process3.Terminology3.1 DefinitionsFor general definitions of terms relating tometallic-coated steel products,see Terminology A902.1This test method is under the jurisdiction of ASTM Committee A05 onMetallic-Coated Iron and Steel Products and is the direct responsibility ofSubcommittee A05.07 on Methods of Testing.Current edition approved May 1,2016.Published June 2016.Originallyapproved in 1979.Last previous edition approved in 2011 as A754/A754M 11.DOI:10.1520/A0754_A0754M-11R16.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.2 Definitions of Terms Specific to This Standard:3.2.1averaging time,nthe period over which an elec-tronic measuring instrument acquires samples or“counts”priorto each update of coating weight(mass)output;refer to X1.2for a more detailed explanation.3.2.2 response time,nthe time required for a coatingweight(mass)gauge to detect 90%of a 10%step change incoating weight(mass).3.2.3 sample,nthe area of moving sheet that must bemeasured under standardized conditions to develop a singledetermination of coating weight(mass).3.2.4 standards,nthe physical standards,either externalor internal,that are used to calibrate the measuring instrument.3.2.5 substrate,nthe steel sheet upon which the metalliccoating is applied.3.2.6 time constant,nan electronic filtering term,uniqueto the design of each type of measuring instrument,that definesthe