1、Designation:C34687(Reapproved 2014)Standard Test Method for45-deg Specular Gloss of Ceramic Materials1This standard is issued under the fixed designation C346;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.
2、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 the specu-lar gloss of porcelain enameled specimens,but may be appli-cable to other specimen
3、s having similar reflection characteris-tics.This test method may be used to compare the gloss ofporcelain enameled specimens or to provide an index of acid orabrasion resistance by measurement of gloss loss.NOTE1Specular gloss is one of several related appearance attributesthat produce the sensatio
4、n of glossiness.For this reason,specular glossmeasurements may not always correlate well with visual rankings ofglossiness.NOTE2Improved correlations with visual judgments can sometimesbe achieved by the use of instruments with different geometries than thosespecified herein.Refer to Test Method D52
5、3 for 20,60,and 85-deggeometries.Values generally cannot be predicated for one geometry frommeasurements made with another.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-pr
6、iate 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 GlossE97 Method of Test for Directional Reflectance Factor,45-Deg 0-Deg,of Opaque Specimens by Broad-BandFilter Reflectomet
7、ry(Withdrawn 1991)33.Terminology3.1 Definitions:3.1.1 specular glossratio of reflected to incident light,times 1000,for specified apertures of illumination and recep-tion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.NOTE3In this operational definition,the qua
8、ntity defined as speculargloss is composed of surface-reflected and body-reflected components.For some low-gloss measurements,an approximate evaluation of thesurface-reflected component of specular gloss may be required(seeSection 9).3.1.2 45-deg specular glossfraction of visible light inci-dent upo
9、n the specimens at 45 to the normal that is reflectedin the direction of mirror reflection.NOTE4Under ideal conditions,the incident beam should consist ofparallel light,and only light reflected in the true direction of mirrorreflection should be accepted for measurement.3.1.3 source apertureangular
10、size(solid angle)of the lightsource(lamp filament,if an incandescent source is used)measured from the center of the incident beam lens.3.1.4 receptor apertureangular size(solid angle)of thereceptor window,measured from the center of the receptorlens.4.Significance and Use4.1 This test method may be
11、used to compare the gloss ofporcelain enamel,ceramic,and other finishes or to provide acomparison of their resistance to attack from acid,alkali,orother environmental factors by measurement of gloss loss.5.Apparatus5.1 Instrumental ComponentsThe apparatus shall consistof an incandescent light source
12、 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
13、 region of the spectrum.5.2 Geometric ConditionsThe axis of the incident beamshall be 45 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
14、 shall form animage of the source in the center of the receptor window.Theangular dimensions of the source and receptor shall be asspecified below:1This test method is under the jurisdiction ofASTM Committee B08 on Metallicand Inorganic Coatings and is the direct responsibility of Subcommittee B08.1
15、2 onMaterials for Porcelain Enamel and Ceramic-Metal Systems.19th St.,Suite 200,Arlington,VA 22209.Current edition approved May 1,2014.Published May 2014.Originallyapproved in 1954.Last previous edition approved in 2009 as C346 87(2009).DOI:10.1520/C0346-87R14.2For referenced ASTM standards,visit th
16、e 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.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 AperturesIn Plane ofMeasurement,AdegPerpendicular to Planeof Measurement,AdegSource1.4 0.43.0 1.0Receiver8.0 0.
