ASTM D4449-2008 类似外表的表面之间不同光泽的目视评定标准试验方法

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【英文标准名称】:StandardTestMethodforVisualEvaluationofGlossDifferencesBetweenSurfacesofSimilarAppearance
【原文标准名称】:类似外表的表面之间不同光泽的目视评定标准试验方法
【标准号】:ASTMD4449-2008
【标准状态】:现行
【国别】:美国
【发布日期】:2008
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:E12.11
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:distinctnessofimage;gloss;haze;visualgloss;Reflectanceandreflectivity--paints/relatedcoatings/materials;Surfaceanalysis--paints/relatedcoatings/materials;Visualexamination--paints/relatedcoatings/materials;Absorption;Angleofincidence;
【摘要】:Glossisassociatedwiththecapacityofasurfacetoreflectmorelightinsomedirectionsthaninothers.Thedirectionsassociatedwithmirror(orspecular)reflectionnormallyhavethehighestreflectances.Glossisbestseenandanalyzedwhenthesurfacesstudiedareilluminatedbyalightsourcethatprovidesstrongcontrastingpatternsoflightanddark.Suchalightsourceisdescribedinthistestmethod.Thesimplestconceptofglossisthatitcorrespondstothemirror-likereflectancesofsurfaces.However,thedistributionsandintensitiesofthissurface-reflectedlightare(forrealmaterials)highlyvariableandaffectedbyavarietyoffactors:surfacesmoothnessandcontour,refractiveindex,absorptance,angleofincidence,and(toagenerallysmallextent)wavelength.Fromthegreatvarietyofsurface-reflectionpatternsmetinmaterialsofcommerce,ithasbeenpossibletoidentifysevensurface-reflectioncriteriaorx201C;typesofglossx201D;regularlyusedbyskilledtechnologistsforintercomparingandratingtheirproductsforgloss.Sixofthesevencriteria,orx201C;typesofgloss,x201D;areidentifiedinthesectionondefinitions.Theseventh,lusterorcontrastgloss,isseldomofconcerntothecoatingsindustry.1.1Thistestmethodcoversthevisualevaluationofglossdifferencesofcoatingsurfaces,usingspecialtypesoflampsforillumination.Itidentifiessixaspectsortypesofglossthatonemaylookforwhenusingthelamptoassessglossdifferencesbetweensurfaces.Itdescribestheconditionsforusingthelampstobestidentifysmalldifferencesineachofthesixtypesofgloss.Fourlevelsofvisualglossdifferencesaredistinguished.1.2Whilethistechniqueisusefulforbothweatheredandunweatheredspecimens,ithasnotbeenappliedtometallics.1.3Thevaluesstatedininch-poundunitsaretoberegardedasstandard.ThevaluesgiveninparenthesesaremathematicalconversionstoSIunitsthatareprovidedforinformationonlyandarenotconsideredstandard.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityofwhoeverusesthisstandardtoconsultandestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:G51
【国际标准分类号】:87_040
【页数】:6P.;A4
【正文语种】:英语