ASTM_D_7127_-_13.pdf

Designation:D712713Standard Test Method forMeasurement of Surface Roughness of Abrasive BlastCleaned Metal Surfaces Using a Portable Stylus Instrument1This standard is issued under the fixed designation D7127;the number immediately following the 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.1.Scope1.1 This test method describes a shop or field procedure fordetermination of roughness characteristics of surfaces preparedfor painting by abrasive blasting.The procedure uses a portableskidded or non-skidded stylus profile tracing instrument.Themeasured characteristics are:Rt and Rpc.Additional measuresof profile height(Rmax and/or Rz)may also be obtained asagreed upon by purchaser and seller.(The digitally-determinedprofile parameters Rt,Rmax,Ry and Rzlmax are extremelysimilar in definition.)1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.3 In general,this method should be limited to the mea-surement of surface roughness where Rt is in the range 10 to150 m(0.4 to 6 mil)and where the Peak Count,Rpc is lessthan 180 peaks/cm(450 peaks/in.).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 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:2D4417 Test Methods for Field Measurement of SurfaceProfile of Blast Cleaned SteelE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method2.2 ASME Standard:ASME B46.1-2002 Surface Texture,Surface RoughnessWaviness and Lay32.3 ISO Standards:ISO4287:1997 GeometricalProductSpecifications(GPS)SurfaceTexture:ProfileMethodTerms,Definitions,and Surface Parameters43.Terminology3.1 DefinitionsThe following definitions are provided asan aid to users of this document.Formal definitions of thesurface roughness and instrument parameters below are con-tained in the referenced standards(Fig.1).3.1.1 deadband,nthat distance above and below the meanline that a continuous trace line must cross in both directions(up and down)to count as a single peak.3.1.1.1 DiscussionUse of a deadband diminishes the ef-fect of small,spurious peaks due to noise.3.1.2 evaluation length,na sequence of five consecutivesampling lengths.3.1.3 Rpc,nthe number of peak/valley pairs,per unit oflength,extending outside a“deadband”centered on the meanline.3.1.4 Rt,nthe vertical distance between the highest peakand lowest valley within any given evaluation length.3.1.5 Rmax,nthe greatest vertical distance between high-est peak and lowest valley for any of the five sampling lengthsthat comprise an evaluation length.3.1.6 Rz,nthe vertical distance between the highest peakand lowest valley in a sampling length averaged over the fivesampling lengths comprising the evaluation length.3.1.7 sampling length,nthe nominal distance parallel tothe surface being assessed within which a single value of asurface parameter is determined.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.46 on Industrial Protective Coatings.Current edition approved Feb.1,2013.Published May 2013.Originallyapproved in 2005.Last previous edition approved in 2005 as D7127 05.DOI:10.1520/D7127-13.2For 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.3Available from American Society of Mechanical Engineers(ASME),ASMEInternational Headquarters,Three Park Ave.,New York,NY 10016-5990,http:/www.asme.org.4Available from International Organization for Standardization(ISO),1,ch.dela Voie-Creuse,CP 56,CH-1211 Geneva 20,Switzerland,http:/www.iso.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.1.8 surface preparation,nthe cleaning and profiling of ametallic surface using an abrasive blast media or mechanicalmeans to prepare that surface for coating.3.1.9 surface profile,nfor purposes of the standard,thepositive and negative vertical deviations(peaks and valleys)are measured from a mean line approximately the center of theprofile being evaluated.3.1.10 surface roughness,nthe combined characteristicsof surface profile(height)and peak count(linear density)for asurface.3.1.11 traversing length,nseven sampling lengths com-prising the evaluation length and the pre-travel and post-travelsegments.4.Summary of