測控專業(yè)英語Unit 4

Unit4

測控技術(shù)與儀器專業(yè)英語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)測量儀器與一個(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，儀器校準(zhǔn)表明了其測量誤差的確定限度。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、無線頻率干擾、接地和線電壓調(diào)節(jié)。2.52.8Unit4CalibrationThecalibrationprocedureandinstrumentperformancechecksaregenerallyspecifiedbytheinstrumentmanufacturerinthemanualsthatareprovidedwiththeinstrument．校準(zhǔn)過程和儀器性能檢查通常由儀器廠商在隨儀器提供的手冊中指定或設(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

測控技術(shù)與儀器專業(yè)英語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)測量儀器能夠測量在其測量范圍內(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)被測量在測量范圍內(nèi)連續(xù)變化時(shí)，某些測量儀器以離散的階躍形式改變其輸出，而非連續(xù)方式。這類測量儀器的分辨率即是輸出的一次階躍。2.21MeasurementThedeadbandofameasuringinstrumentisthesmallestchangeinthemeasuredvariablethatwillresultinameasurablechangeintheoutput.測量儀器的死區(qū)是對應(yīng)于輸出可測變化的被測量最小變化值。Obviously,ameasuringinstrumentcannotmeasurechangesinthemeasuredvariablethataresmallerthanitsdeadband．Thresholdisanothernamefordeadband．很明顯，測量儀器無法測量被測量小于其死區(qū)的變化。閾值是死區(qū)的另一個(gè)名稱。3.13.21MeasurementThesensitivityofameasuringinstrumentistheratioofthechangeinoutputdividedbythechangeintheinputthatcausedthechangeinoutput.

測量儀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．

測量儀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