ASTM_C_584_-_81_2016.pdf

Designation:C58481(Reapproved 2016)Standard Test Method forSpecular Gloss of Glazed Ceramic Whitewares and RelatedProducts1This standard is issued under the fixed designation C584;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 covers the determination of 60 specu-lar gloss of glazed ceramic whitewares and related products.1.2 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:2D523 Test Method for Specular Gloss3.Terminology3.1 Definitions:3.1.1 specular glossthe ratio of reflected to incident light,times 1000,for specified apertures of illumination and recep-tion when the axis of reception coincides with the mirror imageof the axis of illumination.34.Significance and Use4.1 This test method provides a means of establishingspecular gloss limits for bright,semi-mat,and mat glazedsurfaces.It is realized that specular gloss measurements do notalways correlate well with visual rankings of glossiness be-cause specular gloss is only one of several related appearanceattributes that produce the sensation of gloss.However,theprescribed test method is of sufficient accuracy for the intendedpurpose.NOTE1If a greater degree of distinction between bright glazedsurfaces is desired,the 20 geometry instrument will provide it.45.Apparatus5.1 Instrumental ComponentsThe apparatus shall consistof an incandescent light source and lens furnishing an incidentbeam of rays of required aperture,means for locating thesurface of the specimen,and a receptor located to receive therequired pyramid of rays reflected from the specimen.Thereceptor shall be a photosensitive device having maximumresponse near the middle of the visible region of the specimen.5.2 Geometric ConditionsThe axis of the incident beamshall be 60 from the perpendicular to the specimen surface.The axis of the receptor beam shall be coincident with themirror image of the axis of the incident beam.A flat piece ofpolished black glass in the specimen position shall form animage of the source in the center of the receptor window.Thelength of the illuminated area of the specimen shall be equal tonot more than one third the distance from the center of this areato the receptor field stop.The axis of the incident beam and theaxis of the receptor shall be within 0.1 of the nominal valueindicated by the geometry.The dimensions and tolerances ofthe source and receptor shall be as indicated in Table 1(seealso Test Method D523).The angular dimensions of thereceptor field stop are measured from the receptor lens in acollimated-beam type instrument,and from the test surface ina converging-beam type instrument.See Fig.1 for a general-ized illustration of the dimensions.The tolerances are chosenso that errors of no more than one gloss unit at any point on thescale will result from errors in the source and receptorapertures.45.3 VignettingThere shall be no vignetting of rays that liewithin the field angles specified in 5.2.5.4 Spectral ConditionsResults should not differ signifi-cantly from those obtained with a source-filter photocellcombination that is spectrally corrected to yield CIE luminousefficiency with CIE Source C.Since specular reflection is,in1This test method is under the jurisdiction ofASTM Committee C21 on CeramicWhitewares and Related Products and is the direct responsibility of SubcommitteeC21.03 on Methods for Whitewares and Environmental Concerns.Current edition approved July 1,2016.Published July 2016.Originally approvedin 1965.Last previous edition approved in 2011 as C584 81(2011).DOI:10.1520/C058481R16.2For 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.DOI:10.1520/C0584-81R06.3See Illing,A.M.,“Comparison of Instrument Measurement and VisualEstimation of Specular Gloss of Glazed Ceramic Tile,”Materials Research&Standards,Vol 2,No.2,Feb.1962,p.117.4For more complete data see Hammond III,H.K.,and Nimeroff,I.,“Measure-ment of Sixty-Degree Specular Gloss,”Journal of Research,Nat.Bureau Standards,Vol 44,June 1950(RP 2105):also Hunter,R.S.,“Gloss Evaluation of Materials,”ASTM Bulletin,No.186,December 1962.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 general,spectrally nonselective,spectral corrections need beapplied only to highly chromatic,low-gloss specimens uponagreement of users of this method