外文翻译---数据采集：简介

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1、附录A英文文献原文DataAcquisition:AnIntroductionBruxtonCorporationThisisaninformalintroductiondigitaldataacquisitionhardware.ItisprimarilydirectedtowardsassistingintheselectionofappropriatehardwareforrecordingwiththeAcquireprogram.OverviewInprinciple,dataacquisitionhardwareisquitesimple.AnA/

2、Dconverterdeliversasequenceofvaluesrepresentingananalogsignaltoanacquisitionprogram.Inpractice,selectingandproperlyusingdataacquisitionhardwareismorecomplex.Thisdocumentprovidesaninformalintroductiontothetopic..Manyoftheexamplesaretakenfrompatch-clamprecording.Thistechniquerequiresa

3、ccurateacquisitionoflow-levelsignals(picoamperes)withbandwidthintheaudiorange(upto10kHz).BackgroundAdataacquisitionsystemconvertsasignalderivedfromasensorintoasequenceofdigitalvalues.Thesensorisconnectedtoanamplifier,whichconvertsthesignalintoapotential.Theamplifierisinturnconnected

4、toadigitizer,whichcontainsanA/Dconverter.Thedigitizerproducesasequenceofvaluesrepresentingthesignal.SignalSourceThesourceofmostsignalstobedigitizedisasensor,connectedtoanamplifierwithappropriatesignalconditioning.Theamplifierdeliversanelectricalsignal.Thissignalisthendigitizedusinga

5、nA/Dconverter.Forpatch-clamprecording,thesensorsaresolutionfilledpipettes.Thepipetteisconnectedtoapatch-clampamplifierthatconvertsthevoltageatthepipetteorthecurrentthroughthepipettetoahigh-levelsignal.Byconvention,thefull-scaleoutputrangeofapatch-clampamplifieris±10V,matchingtherang

6、eofcommoninstrumentationqualitydigitizers.DigitizerAdigitizerconvertsoneormorechannelsofanalogsignaltoasequenceofcorrespondingdigitalvalues.TheheartofadigitizerisanA/Dconverter,adevicethatsamplesananalogsignalandconvertsthesampletoadigitalvalue.Forexample,forrecordingfromasingleionc

7、hannel,thedigitizermightdeterminetheoutputofthepatchclampamplifieronceevery50msandprovidetheresultingvaluetothecomputer.SamplingTheoremThepurposeofdataacquisitionistoanalyzeananalogsignalindigitalform.Forthistobepossible,thesequenceofvaluesproducedbyadigitizermustrepresenttheorigina

8、lanalogsignal.Thesa