ASTM D7438-2008 手持式水分仪应用和现场校准的标准实施规程

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【英文标准名称】:StandardPracticeforFieldCalibrationandApplicationofHand-HeldMoistureMeters
【原文标准名称】:手持式水分仪应用和现场校准的标准实施规程
【标准号】:ASTMD7438-2008
【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】:D07.01
【标准类型】:(Practice)
【标准水平】:()
【中文主题词】:
【英文主题词】:
【摘要】:Hand-heldmetersprovidearapidmeansofsamplingmoisturecontentofwood-basedmaterialsduringandafterprocessingtomaintainqualityassuranceandcompliancewithstandards.However,thesemeasurementsareinferential;thatis,electricalparametersaremeasuredandcomparedagainstacalibrationtoobtainanindirectmeasureofmoisturecontent.Theelectricalmeasurementsareinfluencedbyactualmoisturecontent,anumberofotherwoodvariables,environmentalconditions,geometryofthemeasuringprobecircuitry,anddesignofthemeter.Themaximumaccuracycanonlybeobtainedbyanawarenessoftheeffectofeachparameteronthemeteroutputandcorrectionofreadingsasspecifiedbythesetestmethods.AppendixX1isacommentarythatprovidesexplanationofthemandatorysectionsanddiscussionofhistoricalpractices.AppendixX2addressestheinfluenceofprocessandwoodvariables.Thispracticeprovidesforcalibrationandapplicationofwoodproductsthatcontaincommercialcharacteristicsandthatreflectthemanufacturingenvironment.Mostusesofhand-heldmoisturemetersemploycorrelative(predictive)relationshipsbetweenthemeterreadingandwoodareasorvolumesthatexceedthatofthedirectmetermeasurement(forexample,largerspecimens,piecesoflumber,lots).Thefieldcalibrationsectionofthispracticeanticipatesthepotentialneedforthistypeofsampling.ThesecorrelativeusesareexaminedinAppendixX3.1.1Thispracticeappliestothemeasurementofmoisturecontentofsolidwood,includingsolidwoodproductscontainingadditives,thatis,chemicalsoradhesives,byhand-heldmoisturemetersunderconditionsofend-use.1.1.1Thispracticeincludescalibration,use,andinterpretationofmetersforconditionsthatrelatetowoodproductcharacteristics,suchasnonuniformgrainandgrowthringorientation,andtoend-useprocessconditions,suchasmoisturegradients.1.1.2Metersemployingdifferingtechnologiesmaynotprovideequivalentreadingsunderthesameconditions.Whenthispracticehasbeenapplied,itisassumedthatthereferencedmeterisacceptableunlessotherwisespecified.MetersshallhavebeencalibratedbyTestMethodsD4444.1.2Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:N51
【国际标准分类号】:79_120_99
【页数】:10P.;A4
【正文语种】:英语