Designation:D4449−15StandardTestMethodforVisualEvaluationofGlossDifferencesBetweenSurfacesofSimilarAppearance1ThisstandardisissuedunderthefixeddesignationD4449;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversthevisualevaluationofglossdifferencesofcoatingsurfaces,usingspecialtypesoflampsforillumination.Itidentifiessixaspectsortypesofglossthatonemaylookforwhenusingthelamptoassessglossdifferencesbetweensurfaces.Itdescribestheconditionsforusingthelampstobestidentifysmalldifferencesineachofthesixtypesofgloss.Fourlevelsofvisualglossdifferencesaredistin-guished.1.2Whilethistechniqueisusefulforbothweatheredandunweatheredspecimens,ithasnotbeenappliedtometallics.1.3Thevaluesstatedininch-poundunitsaretoberegardedasstandard.ThevaluesgiveninparenthesesaremathematicalconversionstoSIunitsthatareprovidedforinformationonlyandarenotconsideredstandard.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityofwhoeverusesthisstandardtoconsultandestablishappropriatesafetyandhealthpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D3964PracticeforSelectionofCoatingSpecimensforAppearanceMeasurementsE284TerminologyofAppearance3.Terminology3.1Definitions—Fordefinitionsoftermsusedinthismethod,seeTerminologyE284.3.2DefinitionsofTermsSpecifictoThisStandard:3.2.1directionalityofsurface,n—perceivedchangeofglossyappearanceofasurfacewithrotationofthesurfaceinitsownplane(seeFig.1).3.2.2gloss,distinctness-of-image,n—perceivedsharpnessofimagesreflectedbyanobjectsurface(seeFig.2).3.2.3gloss,ofasurface,n—perceiveddirectionallyselec-tivereflectingpropertiesresponsibleforthedegreetowhichreflectedhighlightsorimagesofobjectsmaybeseenassuperimposedonthesu...
