2023年全國碩士研究生考試考研英語一試題真題(含答案詳解+作文范文)_第1頁
已閱讀1頁,還剩4頁未讀, 繼續(xù)免費(fèi)閱讀

下載本文檔

版權(quán)說明:本文檔由用戶提供并上傳,收益歸屬內(nèi)容提供方,若內(nèi)容存在侵權(quán),請進(jìn)行舉報或認(rèn)領(lǐng)

文檔簡介

1、Designation:E1004?09StardTestMethodfDeterminingElectricalConductivityUsingtheElectromagic(EddyCurrent)Method1ThisstardisissuedunderthefixeddesignationE1004thenumberimmediatelyfollowingthedesignationindicatestheyearofigin

2、aladoptioninthecaseofrevisiontheyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperepsilon()indicatesaneditialchangesincethelastrevisionreapproval.ThisstardhasbeenapprovedfusebyagenciesoftheDep

3、artmentofDefense.1.Scope1.1Thistestmethodcoversaprocedurefdeterminingtheelectricalconductivityofnonmagicmetalsusingtheelectromagic(eddycurrent)method.Theprocedurehasbeenwrittenprimarilyfusewithcommerciallyavailabledirect

4、readingelectricalconductivityinstruments.Generalpurposeeddycurrentinstrumentsmayalsobeusedfelectricalconductivitymeasurementsbutwillnotbeaddressedinthistestmethod.1.2Thistestmethodisapplicabletometalsthathaveeitheraflats

5、lightlycurvedsurfaceincludesmetalswithwithoutathinnonconductivecoating.1.3Eddycurrentdeterminationsofelectricalconductivitymaybeusedinthestingofmetalswithrespecttovariablessuchastypeofalloyagingcolddefmationheattreatment

6、effectsassociatedwithnonunifmheatingoverheatingeffectsofcrosion.Theusefulnessoftheexaminationsofthesepropertiesisdependentontheamountofelectricalconductivitychangecausedbyachangeinthespecificvariable.1.4Electricalconduct

7、ivitywhenevaluatedwitheddycurrentinstrumentsisusuallyexpressedasapercentageoftheconductivityoftheInternationalAnnealedCopperStard(IACS).TheconductivityoftheAnnealedCopperStardisdefinedtobe0.58108Sm(100%IACS)at20C.1.5Thev

8、aluesstatedinSIunitsareregardedasstard.1.6Thisstarddoesnotpurpttoaddressallofthesafetyconcernsifanyassociatedwithitsuse.Itistheresponsibilityoftheuserofthisstardtoestablishappropriatesafetyhealthpracticesdeterminetheappl

9、icabilityofregulatylimitationspritouse.2.ReferencedDocuments2.1ASTMStards:2B193TestMethodfResistivityofElectricalConductMaterialsE105PracticefProbabilitySamplingofMaterialsE122PracticefCalculatingSampleSizetoEstimateWith

10、SpecifiedPrecisiontheAveragefaacteristicofaLotProcessE543SpecificationfAgenciesPerfmingNondestructiveTestingE1316TerminologyfNondestructiveExaminations2.2ASNTDocuments:RecommendedPracticeSNTTC1AfPersonnelQualificationCer

11、tificationInNondestructiveTesting3ANSIASNTCP189StardfQualificationCertificationofNDTPersonnel32.3AIADocument:NAS–410CertificationQualificationofNondestructiveTestingPersonnel43.Terminology3.1Definitions—Definitionsofterm

12、srelatingtoeddycurrentexaminationaregiveninTerminologyE1316.3.2DefinitionsofTermsSpecifictoThisStard:3.2.1temperaturecoeff?cient—thefractionalpercentagechangeinelectricalconductivityperdegreeCelsiuschangeintemperature.4.

13、SignificanceUse4.1Absoluteprobecoilmethodswhenusedinconjunctionwithreferencestardsofknownvalueprovideameansfdeterminingtheelectricalconductivityofnonmagicmaterials.1ThistestmethodisunderthejurisdictionofASTMCommitteeE07o

14、nNondestructiveTestingisthedirectresponsibilityofSubcommitteeE07.07onElectromagicMethod.CurrenteditionapprovedMay152009.PublishedJune2009.iginallyapprovedin1991.Lastpreviouseditionapprovedin2002asE100402.DOI:10.1520E1004

15、09.2FreferencedASTMstardsvisittheASTMwebsitewww.astm.gcontactASTMCustomerServiceat.FAnnualBookofASTMStardsvolumeinfmationrefertothestard’sDocumentSummarypageontheASTMwebsite.3AvailablefromAmericanSocietyfNondestructiveTe

16、sting(ASNT)P.O.Box285181711ArlingateLn.ColumbusOH432280518:www.asnt.g.4AvailablefromAerospaceIndustriesAssociationofAmericaInc.(AIA)1000WilsonBlvd.Suite1700ArlingtonVA222093928:www.aiaaerospace.g.ASummaryofChangessection

17、appearsattheendofthisstardCopyright?ASTMInternational100BarrHarbDrivePOBoxC700WestConshohockenPA194282959.UnitedStates1d5K=~1r!fr~cm!K.50r51(2)d51=psf~m!5o54p31027r51(3)where:s=electricalconductivityofthesampleinSmr=elec

18、tricalresistivityinVmf=examinationfrequencyinHz.Thesefmulasarefnonmagicmaterialswhentherelativepermeabilityrel=1.Ifthethicknessofthesamplethereferencestardsisatleast2.6dtheeffectofthicknessisnegligible.Smallerdepthsofper

19、ation(higherfrequencies)maybedesirablefmeasuringsurfaceeffects.Theeddycurrentdensitydecreasewithdepthisalsoaffectedbythecoildiameter.Thechangeduetocoildiametervariationisnotconsideredintheaboveequation.Consulttheinstrume

20、ntmanufacturerifperationdepthappearstobeasourceoferrinthemeasurement.8.Apparatus8.1ElectronicApparatus—Theelectronicapparatusshallbecapableofenergizingtheprobecoilwithalternatingcurrentsofsuitablefrequenciespowerlevelssh

21、allbecapableofsensingchangesinthemeasuredimpedanceofthecoil.Equipmentmayincludeanysuitablesignalprocessingdevice(phasediscriminatfiltercircuitssofth).Theoutputmaybedisplayedineitheranalogdigitalreadouts.Readoutisnmallyin

22、percentIACSalthoughitmaybescaledfreadingsinotherunits.Additionalapparatussuchascomputersplottersprinterscombinationthereofmaybeusedintherecdingofdata.8.2Probe—Probecoildesignscombineempiricalmathematicaldesignmethodstoch

23、ooseappropriatecombinationsofacteristics.Manyinstrumentsuseoneprobecoil.Ininstrumentswithseveralcoilsthedifferencebetweencoilsisthecoilgeometry.Fmostconductivityinstrumentsthecableconnectingthecoiltotheinstrumentisaninte

24、gralpartofthemeasuringcircuitthecablelengthshouldnotbemodifiedwithoutconsultingtheinstrumentmanufacturermanual.8.2.1Theprobecoilshouldbedesignedtominimizetheeffectofheattransferfromhtocoil.8.3Mechanicalhlingapparatusffee

25、dingthesamplesmovingtheprobecoilbothmaybeusedtoautomateaspecificmeasurement.9.StardizationCalibration9.1Stardization—Turntheinstrumentonallowitsufficienttimetostabilizeinaccdancewiththemanufacturer’sinstructions.Adjustba

26、lancestardizetheconductivitymeteragainsttheinstrument’soperationalstardscompensatetheconductivitymeterfsurfaceroughnessliftoffinaccdancewiththemanufacturer’sinstructions.Ifaliftoffadjustmentisnotavailabledeterminetheacce

27、ptablerangeofliftoffthatwillmeettheaccuracyrequirements.Verifythestardizationoftheconductivitymeteratperiodicintervals(seeSection10).9.1.1Theinstrumentprobereferencestardsshallbestardizedwhilemaintainingthetemperaturewit

28、hin5Foftheambienttemperature.Itisdesirabletoperfmthestardizationatroomtemperature(typically70615F).9.1.2Instrumentswithtwostardizationadjustmentsshallbeadjustedsothattheknownvalueofconductivityisobtainedfbothreferencesta

29、rds.Thereferencestardsusedshouldhaveconductivitiesthatbrackettheconductivityvalueofthesample.9.1.3Someinstrumentshaveonlyonestardizationadjustment.Inthesecasestheinstrumentshouldbestardizedtoareferencestardatoneendofther

30、angetobeexamined.Areferencestardattheotherendoftherangeshouldbeexaminedtoverifythattheerriswithinacceptablelimitsovertheentirerange.9.2ReferenceStards—Electricalconductivityreferencestardsareusuallyclassifiedasprimarysec

31、ondaryoperationalstards.9.2.1PrimaryConductivityStards—Thesearereferencestardsthathavebeenverifiedintermsofthefundamentalunits.Theprimarystardsarekeptinalabatyenvironmentareusedonlytostardizesecondarystards.9.2.2Secondar

32、yConductivityStards—Thesereferencestardshaveavalueassignedthroughcomparisonwithprimarystards.TheprimarystardsusedfassignmentofvaluestothesesecondarystardsshallhavebeenstandardizedusingTestMethodB193.Thesecondarystardsare

33、keptinalabatyenvironmentareusedonlytocalibrateoperationalinstrumentstards.9.2.3OperationalConductivityStards—Thesereferencestardsarestardizedbycomparisonwithsecondarystards.Thesereferencestardsareusedtostardizetheinstrum

34、entduringuse.9.3Referencestardsshouldbeexaminedwitharelativelysmallcoiltodeterminetheunifmityofelectricalconductivityoverthesurfaceofthestard.Boththefrontthebacksurfaceshouldbeexaminedfanyconductivitydifferencesthatmayex

35、ist.Ifpossiblescanthesurfacesatseveraldifferentinputsignalfrequencies.9.4Eachtimethereferencestardsareusedplacetheprobecoilatthesamepositionrelativetothecenterofthestardwithin61?2ofthecoildiameternottoexceed66.35mm(60.25

36、in.)fexample:64mmfan8mmdiametercoil62mmfa4mmdiametercoil.9.5Electricalconductivityreferencestardsarepreciseelectricalstardsshouldbetreatedassuch.Scratchingofthesurfaceofthestardmayintroducemeasurementerr.Avoidpingotherro

37、ughhlingofthestard.Keepthesurfaceofthestardascleanaspossible.Cleanwithanonreactiveliquidasoftclothtissue.Stereferencestardsinaplacewherethetemperatureisrelativelyconstant.Avoidthermalshockingofthereferencestardsplacingth

溫馨提示

  • 1. 本站所有資源如無特殊說明,都需要本地電腦安裝OFFICE2007和PDF閱讀器。圖紙軟件為CAD,CAXA,PROE,UG,SolidWorks等.壓縮文件請下載最新的WinRAR軟件解壓。
  • 2. 本站的文檔不包含任何第三方提供的附件圖紙等,如果需要附件,請聯(lián)系上傳者。文件的所有權(quán)益歸上傳用戶所有。
  • 3. 本站RAR壓縮包中若帶圖紙,網(wǎng)頁內(nèi)容里面會有圖紙預(yù)覽,若沒有圖紙預(yù)覽就沒有圖紙。
  • 4. 未經(jīng)權(quán)益所有人同意不得將文件中的內(nèi)容挪作商業(yè)或盈利用途。
  • 5. 眾賞文庫僅提供信息存儲空間,僅對用戶上傳內(nèi)容的表現(xiàn)方式做保護(hù)處理,對用戶上傳分享的文檔內(nèi)容本身不做任何修改或編輯,并不能對任何下載內(nèi)容負(fù)責(zé)。
  • 6. 下載文件中如有侵權(quán)或不適當(dāng)內(nèi)容,請與我們聯(lián)系,我們立即糾正。
  • 7. 本站不保證下載資源的準(zhǔn)確性、安全性和完整性, 同時也不承擔(dān)用戶因使用這些下載資源對自己和他人造成任何形式的傷害或損失。

評論

0/150

提交評論