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《外文翻譯---降低測量噪聲的五個技巧》由會員上傳分享，免費在線閱讀，更多相關(guān)內(nèi)容在學術(shù)論文-天天文庫。
1、附錄A外文資料翻譯FiveTipstoReduceMeasurementNoiseEnsuringmeasurementaccuracyoftenmeansgoingbeyondreadingrawspecificationsinadatasheet.Understandinganapplicationinthecontextofitselectricalenvironmentisalsoimportantforsecuringsuccess,particularlyinanoisyorindustria
2、lsetting.Groundloops,highcommon-modevoltages,andelectromagneticradiationareallprevalentexamplesofnoisethatcanadverselyaffectasignal.Therearemanytechniquesforreducingnoiseinameasurementsystem,whichincludepropershielding,cabling,andtermination.Beyondtheseco
3、mmonbestpractices,however,thereismoreyoucandotoensurebetternoiseimmunity.Thefollowingfivetechniquesserveasguidelinesforachievingmoreaccuratemeasurementresults.A.RejectDCCommon-ModeVoltageMakinghighlyaccuratemeasurementsoftenstartswithdifferentialreadings.
4、Anidealdifferentialmeasurementdevicereadsonlythepotentialdifferencebetweenthepositiveandnegativeterminalsofitsinstrumentationamplifier(s).Practicaldevices,however,arelimitedintheirabilitytorejectcommon-modevoltages.Common-modevoltageisthevoltagecommontobo
5、ththepositiveandnegativeterminalsofaninstrumentationamplifier.InFigure1,5ViscommontoboththeAI+andAI-terminals,andtheidealdevicereadstheresulting5Vdifferencebetweenthetwoterminals.Figure1Anidealinstrumentationamplifiercompletelyrejectscommon-modevoltages.T
6、hemaximumworkingvoltageofadataacquisition(DAQ)devicereferstothesignal14voltageplusthecommon-modevoltageandspecifiesthelargestpotentialthatmayexistbetweenaninputandearthground.ThemaximumworkingvoltageformostDAQdevicesisthesameastheinputrangeoftheinstrument
7、ationamplifier.Forexample,low-costMSeriesDAQdevicessuchastheNI6220deviceshaveamaximumworkingvoltageof11V;noinputsignalcanexceed11Vwithoutcausingdamagetotheamplifier.IsolationcandramaticallyincreasethemaximumworkingvoltageofaDAQdevice.Inthecontextofameasur
8、ementsystem,“isolation”meansphysicallyandelectricallyseparatingtwopartsofacircuit.Anisolatorpassesdatafromonepartofthecircuittoanotherwithoutconductingelectricity.Becausecurrentcannotflowacrossthisisolationbarrier,y
