Designation:E1944−98(Reapproved2013)StandardPracticeforDescribingandMeasuringPerformanceofLaboratoryFourierTransformNear-Infrared(FT-NIR)Spectrometers:LevelZeroandLevelOneTests1ThisstandardisissuedunderthefixeddesignationE1944;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1ThispracticecoverstwolevelsofteststomeasuretheperformanceoflaboratoryFouriertransformnearinfrared(FT-NIR)spectrometers.Thispracticeappliestotheshort-wavenearinfraredregion,approximately800nm(12500cm-1)to1100nm(9090.91cm-1);andthelong-wavelengthnearinfraredregion,approximately1100nm(9090.91cm-1)to2500nm(4000cm-1).Thispracticeisintendedmainlyfortransmittancemeasurementsofgasesandliquids,althoughitisbroadlyapplicableforreflectancemeasurements.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2E131TerminologyRelatingtoMolecularSpectroscopyE168PracticesforGeneralTechniquesofInfraredQuanti-tativeAnalysisE932PracticeforDescribingandMeasuringPerformanceofDispersiveInfraredSpectrometersE1252PracticeforGeneralTechniquesforObtainingInfra-redSpectraforQualitativeAnalysisE1421PracticeforDescribingandMeasuringPerformanceofFourierTransformMid-Infrared(FT-MIR)Spectrom-eters:LevelZeroandLevelOneTests3.Terminology3.1Fordefinitionsoftermsusedinthispractice,refertoTerminologyE131.Allidentificationsofspectralregionsandabsorbancebandpositionsaregiveninnanometers(nm),andwavenumbers(cm-1);andspectralenergy,transmittance,reflectance,andabsorbancearesignifiedbythelettersE,T,R...
