Designation:E2228−10StandardGuideforMicroscopicalExaminationofTextileFibers1ThisstandardisissuedunderthefixeddesignationE2228;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thissectiondescribesguidelinesformicroscopicalexaminationsemployedinforensicfibercharacterization,iden-tification,andcomparison.Severaltypesoflightmicroscopesareused,including,stereobinocular,polarizedlight,compari-son,fluorescence,andinterference.Incertaininstances,thescanningelectronmicroscopemayyieldadditionalinforma-tion.Selectwhichtest(s)ortechniquestousebaseduponthenatureandextentofthefiberevidence.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.2.ReferencedDocuments2.1ASTMStandards:2D123TerminologyRelatingtoTextilesD276TestMethodsforIdentificationofFibersinTextiles2.2AATCCStandards:3AATCCTestMethod20:QualitativeTestMethod20–2007FiberAnalysis:Qualitative3.Terminology3.1Definitions—Fordefinitionsoftermsusedinthisguide,refertoTerminologyD123.3.2DefinitionsofTermsSpecifictoThisStandard:3.2.1anisotropic—acharacteristicofanobject,whichhasopticalpropertiesthatdifferaccordingtothedirectioninwhichlighttravelsthroughtheobjectwhenviewedinpolarizedlight.3.2.2barrierfilter—afilterusedinfluorescencemicroscopythatsuppressesunnecessaryexcitationlightthathasnotbeenabsorbedbythefiberandselectivelytransmitsonlylightofgreaterwavelengthsthanthecut-offwavelength.3.2.3Beckeline—thebrighthaloneartheboundaryofafiberthatmoveswithrespecttothatboundaryasthefiberismovedthroughbestfocuswhenthefiberismountedinamediumthatdiffersfromitsrefractiveindex.3.2.4Beckelinemethod—amethodfordeterminingtherefractiveindexofafiberrelativetoitsmountantbynotingthedirectioninwhichtheBeckelinemoveswhenthefocusischanged.3.2.4.1Discussion—TheBeckelinewillalw...
