1、Designation: D7127 17Standard 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
2、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 roug
3、hness 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
4、 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
5、 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 SSPC standard SSPC-PA 17 provides additional guid-ance for determining conformance with surface profile require-ments.1.5 This standard
6、 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.1.6 This interna
7、tional 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 (TBT) Com
8、mittee.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 Method
9、2.2 SSPC Standard:3SSPC-PA 17 Procedure for Determining Conformance toSteel Profile/Surface Roughness/Peak Count Require-ments2.3 ASME Standard:ASME B46.1-2002 Surface Texture, Surface RoughnessWaviness and Lay42.4 ISO Standards:ISO 4287: 1997 Geometrical Product Specifications(GPS)Surface Texture:
10、Profile MethodTerms,Definitions, and Surface Parameters53. 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 deadban
11、d, 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.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibilit
12、y ofSubcommittee D01.46 on Industrial Protective Coatings.Current edition approved Dec. 1, 2017. Published January 2018. Originallyapproved in 2005. Last previous edition approved in 2013 as D7127 13. DOI:10.1520/D7127-17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontac
13、t 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 The Society for Protective Coatings (SSPC), 800 TrumbullDrive, Pittsburgh, PA 15205-4365, http:/www.sspc.org.4Available fro
14、m American Society of Mechanical Engineers (ASME), ASMEInternational Headquarters, Three Park Ave., New York, NY 10016-5990, http:/www.asme.org.5Available from International Organization for Standardization (ISO), 1, ch. dela Voie-Creuse, CP 56, CH-1211 Geneva 20, Switzerland, http:/www.iso.org.Copy
15、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 Internati
16、onal Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.13.1.1.1 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
17、.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 low
18、est 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 paral
19、lel tothe surface being assessed within which a single value of asurface parameter is determined.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 th
20、e 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 trav
21、ersing length, nseven sampling lengths com-prising the evaluation length and the pre-travel and post-travelsegments.Top Illustration of stylus device terminology: sampling length,evaluation length, traverse length.Bottom Expanded view of a single sampling length to illustratesurface structure termin
22、ology:Rt: difference between highest peak and lowest valley over theevaluation length.Rmax: difference between highest peak and lowest valley over thesampling. lengthPc: number of peak/valley pairs, per unit length extending outsidea deadband centered on the mean line.FIG. 1 Illustration of Terminol
23、ogyD7127 1724. Summary of Test Method4.1 This test method describes the proper use of a portablestylus surface roughness measuring device to evaluate specificsurface parameters and evaluate their suitability for the appli-cation of the selected coating to the surface being prepared byabrasive blasti
24、ng, or other mechanical means, prior to applica-tion.4.2 The method describes considerations relevant to setupof stylus instruments for acquisition of required surface rough-ness parameters.5. Significance and Use5.1 This method may be useful in assuring conformance ofa prepared surface to profile r
25、equirements specified by themanufacturer of a protective coating.5.2 This method includes determination of the peak density(number of profile peaks in a specified distance). Someworkers in the field believe that optimizing peak height andpeak density can improve coating adhesion.5.3 This method allo
26、ws specifiers to objectively definesurface texture after abrasive blast cleaning rather than usingsubjective terms such as “angular pattern” or “dense anduniform pattern.”5.4 Because implicit and explicit definitions of “roughness”may differ substantially, numerical characterizations of profilecanno
27、t be compared directly across different methods.6. Apparatus6.1 The apparatus consists of a portable skidded or non-skidded electronic surface roughness measurement instrument(“tester”) capable of measuring Rt in compliance with ISO4287 and Rpc in compliance with ASME B46.1. The apparatusshould have
28、 a vertical range of at least 300 m (12 mil) andpermit a sampling length of 2.5 mm (0.1 in.) and an evaluationlength of 12.5 mm (0.5 in.). (Laboratory experience suggeststhis vertical range is a practical requirement to meet theprovisions of 6.2.) In 2009 there are believed to be at least threemanuf
29、actures of such devices.66.2 The apparatus should include a stylus with a tip radiusof 5 m (0.2 mil), and permit recording of Rt in the range 10to 150 mm (0.4 to 6 mil) and Rpc up to 180/cm (450/in.).6.3 Surface deviations are sensed by the stylus and con-verted to electrical signals within the devi
30、ce. Internal process-ing converts these signals into standard surface characteriza-tion parameters, which are then displayed or printed.7. Preparation of Apparatus7.1 Set the apparatus to display, and, if so equipped, recordthe chosen parameters in accordance with the manufacturersinstructions.7.2 T
31、he evaluation length should be set to 5 samplinglengths. The sampling length and evaluation length should beset to 2.5 mm (0.1 in.) and 12.5 mm (0.5 in.), respectively.7.3 The traversing length of the apparatus should be set (ormanufacturer preset) to include pre-travel and post-travelsegments, usua
32、lly equal to one sampling length at the begin-ning and one sampling length at the evaluation length. Theseportions of a traverse are, however, discarded by the instrumentin its calculation of surface parameters.7.4 The low frequency (“long wavelength” or “cutoff”) filtershould be set to “Gaussian” o
33、r “Gaussian 50 %.” In general, thedefault setting will be compliant.7.5 If the apparatus has a high frequency (“short wave-length” or “Ls”) filter should be set to “off.”7.6 The apparatus should be adjusted (if necessary) to adeadband width (C1 = C2) in the range 0.5 to 2.0 m (20 to80 in.). The choi
34、ce of deadband for profiles as large as thosediscussed in this standard will have little effect on the mea-surements. In general, the default setting will be compliant.7.7 The accuracy of the apparatus should be checkedregularly using a calibration block available from the equip-ment manufacturer us
35、ing their written procedure and at theirrecommended interval.8. Preparation of the Sample8.1 Select an area of the surface to be tested that is visiblyfree from obvious defects such as scratches, deep marks, orother construction or corrosion defects.8.2 Using a stiff nylon bristle brush, remove any
36、dust orabrasive particles from the surface in the selected sampleevaluation area. If not removed, such dust and micronicmetallic particles may cause damage to the stylus and errone-ous readings.9. Calibration and Standardization9.1 Precision reproductions of standard surface profiles suchas those us
37、ed by the manufacturer of the equipment, ordescribed in their operational literature, may be used ascalibration standards for the apparatus.10. Procedure10.1 Obtain an initial trace measurement (2 parameters),then four additional trace measurements taken in the compassdirections from the original me
38、asurement and about 3 cm (1in.) away for a total of 5 traces, avoiding obvious surfacedefects.10.2 If the stylus is prevented from making a complete tracedue to a physical interference, such as a deep scratch on thesurface, move the apparatus to a close adjacent area away fromthe obvious defect and
39、repeat the trace.10.3 Record the 10 parameters resulting from these fivetraces (2 parameters per trace).NOTE 1SSPC standard SSPC-PA 17 describes a procedure fordetermining the number of locations to characterize the surface and fordetermining compliance with specified profile range.11. Calculation a
40、nd Interpretation of Results11.1 Calculate the five measurement average for each of thetwo parameters (Rt and Rpc).6Research Report to be developed with a listing of manufacturers.D7127 17312. Report12.1 At a minimum, the report should contain the followingitems:12.1.1 The sampling length and evalua
41、tion length,12.1.2 Jobsite and location at which the measurement wasmade,12.1.3 The values of the five trace measurements for each ofthe parameters measured (Rt and Rpc at a minimum) and theiraverages, and12.1.4 Instrument used to obtain the measurements, includ-ing model number. Note whether a skid
42、ded or non-skiddedinstrument is used.13. Precision and Bias13.1 The precision of this test method is based on anintralaboratory study conducted in 2011. Eleven laboratoriesparticipated in this study, analyzing materials representing fivedifferent property types. Each “test result” reported represent
43、san individual determination and the participating labs reportedthree replicate test results for each material type. Practice E691was followed for the design and analysis of the data; the detailsare given in ASTM Research Report RR:D01-1169.7Values intables appearing in this section are taken from t
44、he foregoingreport.13.1.1 The Profile Reproducibility Standard Deviation (Pro-file SR), documented in Table 1 for each of five levels ofprofile, is key to assessing whether a given measurement isstatistically different from either an upper or lower profile limitestablished in advance by the interest
45、ed parties.13.1.2 The term “reproducibility standard deviation” is usedas specified in Practice E177.13.1.3 Similarly, the Peak Count Standard Deviation (PCSR), also documented in Table 1, is key to assessing whether agiven measurement is statistically different from either anupper or lower peak cou
46、nt limit established in advance by theinterested parties.13.1.4 Ameasured profile or peak count that is within eitherlimit of a pre-specified range by an amount equal to SRhas a68 % probability of satisfying specification. A profile within1.5 SRof a specified limit has an 86 % probability of satisfy
47、ingspecification and a profile within 2.0 SRof a specified limit hasa 95 % probability of satisfying the specification. Fig. 2 is aplot, using the data in Table 1, of peak count versus measuredprofile.13.2 BiasAt the time of this study, there was no generallyaccepted reference method suitable for de
48、termining eitherprofile or peak count bias for this test method, therefore noformal statement on bias is being made.13.2.1 Nevertheless, testing in support of Test MethodsD4417 relied on measurements of the same roughness testpanels used to determine precision in Test Method D7127, thepresent standa
49、rd. Comparison of data obtained using these twoprocedures gives a measure of relative method bias. Table 2presents these data.13.2.2 A plot (Fig. 3) of the Portable-Stylus-Instrument-determined parameter Rt against replica tape-determinedprofiles, shows good agreement within the error associatedwith each of the two methods.Aleast-square straight line fittedto profiles for the five surfaces measured using both methodshas a slope of 1.1. Over the tested range, the straight line fitsuggests that profiles measured with the two methods no wherediffer by m
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