ASTM_D_523_-_14.pdf

Designation:D52314Standard Test Method forSpecular Gloss1This standard is issued under the fixed designation D523;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.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 This test method covers the measurement of the speculargloss of nonmetallic specimens for glossmeter geometries of60,20,and 85(1-7).21.2 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.3 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:3D823 Practices for Producing Films of Uniform Thicknessof Paint,Varnish,and Related Products on Test PanelsD3964 Practice for Selection of Coating Specimens forAppearance MeasurementsD3980 Practice for Interlaboratory Testing of Paint andRelated Materials(Withdrawn 1998)4D4039 Test Method for Reflection Haze of High-GlossSurfacesE97 Method of Test for Directional Reflectance Factor,45-Deg 0-Deg,of Opaque Specimens by Broad-BandFilter Reflectometry(Withdrawn 1991)4E430 Test Methods for Measurement of Gloss of High-GlossSurfaces by Abridged Goniophotometry3.Terminology3.1 Definitions:3.1.1 relative luminous reflectance factor,nthe ratio of theluminous flux reflected from a specimen to the luminous fluxreflected from a standard surface under the same geometricconditions.For the purpose of measuring specular gloss,thestandard surface is polished glass.3.1.2 specular gloss,nthe relative luminous reflectancefactor of a specimen in the mirror direction.4.Summary of Test Method4.1 Measurements are made with 60,20,or 85 geometry(8,9).The geometry of angles and apertures is chosen so thatthese procedures may be used as follows:4.1.1 The 60 geometry is used for intercomparing mostspecimens and for determining when the 20 geometry may bemore applicable.4.1.2 The 20 geometry is advantageous for comparingspecimens having 60 gloss values higher than 70.4.1.3 The 85 geometry is used for comparing specimensfor sheen or near-grazing shininess.It is most frequentlyapplied when specimens have 60 gloss values lower than 10.5.Significance and Use5.1 Gloss is associated with the capacity of a surface toreflect more light in directions close to the specular than inothers.Measurements by this test method correlate with visualobservations of surface shininess made at roughly the corre-sponding angles.5.1.1 Measured gloss ratings by this test method are ob-tained by comparing the specular reflectance from the speci-men to that from a black glass standard.Since specularreflectance depends also on the surface refractive index of thespecimen,the measured gloss ratings change as the surfacerefractive index changes.In obtaining the visual gloss ratings,however,it is customary to compare the specular reflectancesof two specimens having similar surface refractive indices.5.2 Other visual aspects of surface appearance,such asdistinctness of reflected images,reflection haze,and texture,are frequently involved in the assessment of gloss(1),(6),(7).Test Method E430 includes techniques for the measurement of1This test method is under the jurisdiction of ASTM Committee E12 on Colorand Appearance and is the direct responsibility of Subcommittee E12.03 onGeometry.Current edition approved Jan.1,2014.Published January 2014.Originallyapproved in 1939.Last previous edition approved in 2008 as D523 08.DOI:10.1520/D0523-14.2The boldface numbers in parentheses refer to the list of references at the end ofthis test method.3For 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.4The 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 both distinctness-of-image gloss and reflection haze.TestMethod D4039 provides an alternative procedure for measur-ing reflection haze.5.3 Little information about the relation of numerical-to-perceptual intervals of specular gloss has been published.However,in many applications the gloss scales of this testmethod have provided instrumental scaling of coated speci-mens that have agreed well with visual scaling(10).5.4 When specimens differing widely in perceived gloss