测控专业英语Unit 4

Unit4

测控技术与仪器专业英语CalibrationChapter1IntroductiontoMeasurementcriterion标准、准则establishedstandard现有标准multiplestandard多重标准feasible可行的specifiedlimit制定的限度calibrate校准performancecheck

性能检查progressivedrift

逐渐地漂移tolerancelimit

随机误差WordsandExpressionsQ1Whatiscalibration,andwhydopeopleperformitatspecifiedintervals?Q2Whatarethestandards,andwhatrequirementmusttheysatisfy?Q3Whatshouldtheseparatecalibrationgroupsdoaccordingtotheirtasksandofficeauthorities?Questionsbeforereading办公权限校准Q4Whatarecalibrationproceduresandinstrumentperformancecheck,andhowaretheyimplemented?Questionsbeforereading校准程序Unit4Calibration

Calibrationreferstothecomparisonofameasurementinstrumenttoastandardorotherinstrumentofknownaccuracyinordertobringtheinstrumentintosubstantialagreementwithanestablishedstandard.

校准是指为了使仪器与已有标准完全一致（匹配）而将一个测量仪器与一个标准的或其他已知准确度的仪器相比较的过程。1.1Unit4CalibrationTheestablishedstandardisnormallyofatleastfourtimesgreateraccuracythantheinstrumentbeingcalibratedortheaverageofmultiplestandardsifthefour-timescriterionisnotfeasible．已有标准通常至少四倍于待校准仪器的准确度，或者当四倍标准不可行时，则采用多重标准平均方式。Tosaythataninstrumentiscalibratedmeansthatitindicatesmeasurementswithinspecifiedlimitsoferrorforthatinstrument．也就是说，仪器校准表明了其测量误差的确定限度。1.31.5Unit4CalibrationTheaccuracyofaninstrumentisdependentonthreemajorcontributingfactors:①Thetimesinceitwaslastcalibrated;②Thedifferencebetweenthecalibrationtemperatureandtheoperatingtemperature;③Theuncertaintyofthestandardusedforcalibration．仪器的准确度取决于三个主要因素：①距离上次校准的时间；②校准和使用时的温差；③用于标定的标准的不确定度。1.9Unit4CalibrationInmostorganizations，calibrationistheresponsibilityofaseparategroup.Thatgroupisresponsibleformaintainingworkingstandards,keepingrecordsofinstrumentsforperiodiccalibrationandcertification,andbeingknowledgeableofthelatestcalibrationprocedures．在大多数组织中，校准由一个独立（或单独的）小组负责。这个小组负责维护现行标准，对仪器的周期性校准和检定进行记录，并清楚了解最近一次校准的过程。2.1Unit4CalibrationThestandardslaboratoryshouldhaveenvironmentalcontrolstoassureconsistencybecauseenvironmentalfactorscanaffecttheaccuracyofcertainstandardsandtheperformanceofinstruments.由于环境因素能影戏那个某些标准的准确度和仪器的性能，所以，标准实验室应具备环境控制（装置）保证（校准和使用的）一致性。Environmentalfactorsthatarecontrolledusuallyincludetemperature,humidity,vibration,dust,radio-frequencyinterference,grounding,andlinevoltageregulation．需要控制的环境因素通常包括温度、湿度、振动、粉尘、无线频率干扰、接地和线电压调节。2.52.8Unit4CalibrationThecalibrationprocedureandinstrumentperformancechecksaregenerallyspecifiedbytheinstrumentmanufacturerinthemanualsthatareprovidedwiththeinstrument．校准过程和仪器性能检查通常由仪器厂商在随仪器提供的手册中指定或设置。Frequentunnecessaryadjustmentsmayalsointerferewiththerecordsforaninstrumentandaccelerateprogressivedriftinvalues.频繁不必要调整可能会影响仪器的记录，并加速数值的逐渐地漂移。3.13.6Unit4CalibrationAnexceptiontothisprocedurecanbemadeiftheparameterisverynearthetolerancelimitandthereisreasontobelieveitmaybeoutoftolerancebeforethenextcalibration.如果参数非常接近公差限，并且有理由相信其可能在下次校准前超差，则要例外。

Thedecisiontoadjustinstrumentsthatareclosetothespecifiedlimitsdependsonthetypeofinstrumentandontheoperatingpracticeandphilosophyofthelaboratorydoingtherecalibration.对于仪器是否因接近设定极限而需调整的决策，取决于仪器的类型和校准实验室的实际操作情况和实验室体系架构。3.73.9Unit5

测控技术与仪器专业英语OperatingCharacteristicChapter1IntroductiontoMeasurement徐小玲range范围span跨度resolution分辨率deadband死区threshold阈值sensitivity灵敏度overload

过载recoverytime

回复时间saturationeffect

饱和效应WordsandExpressionsQ1Whatarethemeaningsofrange,span,andwhatarethedifferencesbetweenthem?Q2Howareresolution,dead-bandandsensitivityrelatedtoanincreaseofmeasurement?Q3Whatarethereliability,over-rangeanddrift?Q4Whatdoesenvironmentofanexperimentinclude?QuestionsbeforereadingMaincontent

Measurement1Operation2EnvironmentalEffects31MeasurementAmeasuringinstrumentcanmeasureanyvalueofavariablewithinitsrangeofmeasurement.Therangeisdefinedbythelowerrangelimitandtheupperrangelimit．一个测量仪器能够测量在其测量范围内的任意变量值。范围是由范围的下限和范围的上限共同定义的。Thespanisthedifferencebetweentheupperrangelimitandthelowerrangelimit．Span=upperrangelimit-lowerrangelimit跨度是上下限之间的差：跨度=范围上限-范围下限1.11.41MeasurementWhenthemeasuredvariableiscontinuouslyvariedovertherange,somemeasuringinstrumentschangetheiroutputindiscretestepsratherthaninacontinuousmanner.Theresolutionofthistypeofmeasuringinstrumentisasinglestepoftheoutput.

当被测量在测量范围内连续变化时，某些测量仪器以离散的阶跃形式改变其输出，而非连续方式。这类测量仪器的分辨率即是输出的一次阶跃。2.21MeasurementThedeadbandofameasuringinstrumentisthesmallestchangeinthemeasuredvariablethatwillresultinameasurablechangeintheoutput.测量仪器的死区是对应于输出可测变化的被测量最小变化值。Obviously,ameasuringinstrumentcannotmeasurechangesinthemeasuredvariablethataresmallerthanitsdeadband．Thresholdisanothernamefordeadband．很明显，测量仪器无法测量被测量小于其死区的变化。阈值是死区的另一个名称。3.13.21MeasurementThesensitivityofameasuringinstrumentistheratioofthechangeinoutputdividedbythechangeintheinputthatcausedthechangeinoutput.

测量仪器的灵敏度即是输出变化量与输入变化量的比值。4.1Maincontent

Measurement1Operation2EnvironmentalEffects32Operation

Thereliabilityofameasuringinstrument

istheprobabilitythatitwilldoitsjobforaspecifiedperiodoftimeunderaspecifiedsetofconditions．

测量仪器的可靠性是它在一些列特定条件下在一段特定时间内完成其工作的可能性。

Overrangeisanyexcessinthevalueofthemeas