Unit4

測(cè)控技術(shù)與儀器專(zhuān)業(yè)英語(yǔ)CalibrationChapter1IntroductiontoMeasurementcriterion標(biāo)準(zhǔn)、準(zhǔn)則establishedstandard現(xiàn)有標(biāo)準(zhǔn)multiplestandard多重標(biāo)準(zhǔn)feasible可行的specifiedlimit制定的限度calibrate校準(zhǔn)performancecheck

性能檢查progressivedrift

逐漸地漂移tolerancelimit

隨機(jī)誤差WordsandExpressionsQ1Whatiscalibration,andwhydopeopleperformitatspecifiedintervals?Q2Whatarethestandards,andwhatrequirementmusttheysatisfy?Q3Whatshouldtheseparatecalibrationgroupsdoaccordingtotheirtasksandofficeauthorities?Questionsbeforereading辦公權(quán)限校準(zhǔn)Q4Whatarecalibrationproceduresandinstrumentperformancecheck,andhowaretheyimplemented?Questionsbeforereading校準(zhǔn)程序Unit4Calibration

Calibrationreferstothecomparisonofameasurementinstrumenttoastandardorotherinstrumentofknownaccuracyinordertobringtheinstrumentintosubstantialagreementwithanestablishedstandard.

校準(zhǔn)是指為了使儀器與已有標(biāo)準(zhǔn)完全一致（匹配）而將一個(gè)測(cè)量?jī)x器與一個(gè)標(biāo)準(zhǔn)的或其他已知準(zhǔn)確度的儀器相比較的過(guò)程。1.1Unit4CalibrationTheestablishedstandardisnormallyofatleastfourtimesgreateraccuracythantheinstrumentbeingcalibratedortheaverageofmultiplestandardsifthefour-timescriterionisnotfeasible．已有標(biāo)準(zhǔn)通常至少四倍于待校準(zhǔn)儀器的準(zhǔn)確度，或者當(dāng)四倍標(biāo)準(zhǔn)不可行時(shí)，則采用多重標(biāo)準(zhǔn)平均方式。Tosaythataninstrumentiscalibratedmeansthatitindicatesmeasurementswithinspecifiedlimitsoferrorforthatinstrument．也就是說(shuō)，儀器校準(zhǔn)表明了其測(cè)量誤差的確定限度。1.31.5Unit4CalibrationTheaccuracyofaninstrumentisdependentonthreemajorcontributingfactors:①Thetimesinceitwaslastcalibrated;②Thedifferencebetweenthecalibrationtemperatureandtheoperatingtemperature;③Theuncertaintyofthestandardusedforcalibration．儀器的準(zhǔn)確度取決于三個(gè)主要因素：①距離上次校準(zhǔn)的時(shí)間；②校準(zhǔn)和使用時(shí)的溫差；③用于標(biāo)定的標(biāo)準(zhǔn)的不確定度。1.9Unit4CalibrationInmostorganizations，calibrationistheresponsibilityofaseparategroup.Thatgroupisresponsibleformaintainingworkingstandards,keepingrecordsofinstrumentsforperiodiccalibrationandcertification,andbeingknowledgeableofthelatestcalibrationprocedures．在大多數(shù)組織中，校準(zhǔn)由一個(gè)獨(dú)立（或單獨(dú)的）小組負(fù)責(zé)。這個(gè)小組負(fù)責(zé)維護(hù)現(xiàn)行標(biāo)準(zhǔn)，對(duì)儀器的周期性校準(zhǔn)和檢定進(jìn)行記錄，并清楚了解最近一次校準(zhǔn)的過(guò)程。2.1Unit4CalibrationThestandardslaboratoryshouldhaveenvironmentalcontrolstoassureconsistencybecauseenvironmentalfactorscanaffecttheaccuracyofcertainstandardsandtheperformanceofinstruments.由于環(huán)境因素能影戲那個(gè)某些標(biāo)準(zhǔn)的準(zhǔn)確度和儀器的性能，所以，標(biāo)準(zhǔn)實(shí)驗(yàn)室應(yīng)具備環(huán)境控制（裝置）保證（校準(zhǔn)和使用的）一致性。Environmentalfactorsthatarecontrolledusuallyincludetemperature,humidity,vibration,dust,radio-frequencyinterference,grounding,andlinevoltageregulation．需要控制的環(huán)境因素通常包括溫度、濕度、振動(dòng)、粉塵、無(wú)線(xiàn)頻率干擾、接地和線(xiàn)電壓調(diào)節(jié)。2.52.8Unit4CalibrationThecalibrationprocedureandinstrumentperformancechecksaregenerallyspecifiedbytheinstrumentmanufacturerinthemanualsthatareprovidedwiththeinstrument．校準(zhǔn)過(guò)程和儀器性能檢查通常由儀器廠商在隨儀器提供的手冊(cè)中指定或設(shè)置。Frequentunnecessaryadjustmentsmayalsointerferewiththerecordsforaninstrumentandaccelerateprogressivedriftinvalues.頻繁不必要調(diào)整可能會(huì)影響儀器的記錄，并加速數(shù)值的逐漸地漂移。3.13.6Unit4CalibrationAnexceptiontothisprocedurecanbemadeiftheparameterisverynearthetolerancelimitandthereisreasontobelieveitmaybeoutoftolerancebeforethenextcalibration.如果參數(shù)非常接近公差限，并且有理由相信其可能在下次校準(zhǔn)前超差，則要例外。

Thedecisiontoadjustinstrumentsthatareclosetothespecifiedlimitsdependsonthetypeofinstrumentandontheoperatingpracticeandphilosophyofthelaboratorydoingtherecalibration.對(duì)于儀器是否因接近設(shè)定極限而需調(diào)整的決策，取決于儀器的類(lèi)型和校準(zhǔn)實(shí)驗(yàn)室的實(shí)際操作情況和實(shí)驗(yàn)室體系架構(gòu)。3.73.9Unit5

測(cè)控技術(shù)與儀器專(zhuān)業(yè)英語(yǔ)OperatingCharacteristicChapter1IntroductiontoMeasurement徐小玲range范圍span跨度resolution分辨率deadband死區(qū)threshold閾值sensitivity靈敏度overload

過(guò)載recoverytime

回復(fù)時(shí)間saturationeffect

飽和效應(yīng)WordsandExpressionsQ1Whatarethemeaningsofrange,span,andwhatarethedifferencesbetweenthem?Q2Howareresolution,dead-bandandsensitivityrelatedtoanincreaseofmeasurement?Q3Whatarethereliability,over-rangeanddrift?Q4Whatdoesenvironmentofanexperimentinclude?QuestionsbeforereadingMaincontent

Measurement1Operation2EnvironmentalEffects31MeasurementAmeasuringinstrumentcanmeasureanyvalueofavariablewithinitsrangeofmeasurement.Therangeisdefinedbythelowerrangelimitandtheupperrangelimit．一個(gè)測(cè)量?jī)x器能夠測(cè)量在其測(cè)量范圍內(nèi)的任意變量值。范圍是由范圍的下限和范圍的上限共同定義的。Thespanisthedifferencebetweentheupperrangelimitandthelowerrangelimit．Span=upperrangelimit-lowerrangelimit跨度是上下限之間的差：跨度=范圍上限-范圍下限1.11.41MeasurementWhenthemeasuredvariableiscontinuouslyvariedovertherange,somemeasuringinstrumentschangetheiroutputindiscretestepsratherthaninacontinuousmanner.Theresolutionofthistypeofmeasuringinstrumentisasinglestepoftheoutput.

當(dāng)被測(cè)量在測(cè)量范圍內(nèi)連續(xù)變化時(shí)，某些測(cè)量?jī)x器以離散的階躍形式改變其輸出，而非連續(xù)方式。這類(lèi)測(cè)量?jī)x器的分辨率即是輸出的一次階躍。2.21MeasurementThedeadbandofameasuringinstrumentisthesmallestchangeinthemeasuredvariablethatwillresultinameasurablechangeintheoutput.測(cè)量?jī)x器的死區(qū)是對(duì)應(yīng)于輸出可測(cè)變化的被測(cè)量最小變化值。Obviously,ameasuringinstrumentcannotmeasurechangesinthemeasuredvariablethataresmallerthanitsdeadband．Thresholdisanothernamefordeadband．很明顯，測(cè)量?jī)x器無(wú)法測(cè)量被測(cè)量小于其死區(qū)的變化。閾值是死區(qū)的另一個(gè)名稱(chēng)。3.13.21MeasurementThesensitivityofameasuringinstrumentistheratioofthechangeinoutputdividedbythechangeintheinputthatcausedthechangeinoutput.

測(cè)量?jī)x器的靈敏度即是輸出變化量與輸入變化量的比值。4.1Maincontent

Measurement1Operation2EnvironmentalEffects32Operation

Thereliabilityofameasuringinstrument

istheprobabilitythatitwilldoitsjobforaspecifiedperiodoftimeunderaspecifiedsetofconditions．

測(cè)量?jī)x器的可靠性是它在一些列特定條件下在一段特定時(shí)間內(nèi)完成其工作的可能性。

Overrangeisanyexcessinthevalueofthemeas