Designation:E1655−17StandardPracticesforInfraredMultivariateQuantitativeAnalysis1ThisstandardisissuedunderthefixeddesignationE1655;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thesepracticescoveraguideforthemultivariatecalibrationofinfraredspectrometersusedindeterminingthephysicalorchemicalcharacteristicsofmaterials.Theseprac-ticesareapplicabletoanalysesconductedinthenearinfrared(NIR)spectralregion(roughly780to2500nm)throughthemidinfrared(MIR)spectralregion(roughly4000to400cm−1).NOTE1—Whilethepracticesdescribedhereindealspecificallywithmid-andnear-infraredanalysis,muchofthemathematicalandproceduraldetailcontainedhereinisalsoapplicableformultivariatequantitativeanalysisdoneusingotherformsofspectroscopy.Theuseriscautionedthattypicalandbestpracticesformultivariatequantitativeanalysisusingotherformsofspectroscopymaydifferfrompracticesdescribedhereinformid-andnear-infraredspectroscopies.1.2Proceduresforcollectingandtreatingdatafordevelop-ingIRcalibrationsareoutlined.Definitions,terms,andcali-brationtechniquesaredescribed.Criteriaforvalidatingtheperformanceofthecalibrationmodelaredescribed.1.3TheimplementationofthesepracticesrequirethattheIRspectrometerhasbeeninstalledincompliancewiththemanufacturer’sspecifications.Inaddition,itassumesthat,atthetimesofcalibrationandofvalidation,theanalyzerisoperatingattheconditionsspecifiedbythemanufacturer.1.4Thesepracticescovertechniquesthatareroutinelyappliedinthenearandmidinfraredspectralregionsforquantitativeanalysis.Thepracticesoutlinedcoverthegeneralcasesforcoarsesolids,finegroundsolids,andliquids.Alltechniquescoveredrequiretheuseofacomputerfordatacollectionandanalysis.1.5Thesepracticesprovideaquestionnaireagainstwhichmultivariatecalibrationscanbeexaminedtodetermineiftheyconformtotherequirementsdefinedherei...
