1、DevelopmentofSensorNewTechnologySensorisonekindcomponentwhichcantransformthephysicalquantity,chemistryquantityandthebiomassintoelectricalsignal.Theoutputsignalhasthedifferentformslikethevoltage,theelectriccurrent,thefrequency,thepulseandsoon,whichcansatisfythesignaltransmission,processing,recording,
2、anddemonstrationandcontroldemands.Soitistheautomaticdetectionsystemandintheautomaticcontrolindustry.IfautomaticTechnologyisusedwider,thensensorismoreimportant.Severalkeywordsofthesensor：1 SensorElementsAlthoughthereareexception,mostsensorconsistofasensingelementandaconversionorcontrolelement.Forexam
3、ple,diaphragms,bellows,straintubesandrings,bourdontubes,andcantileversaresensingelementswhichrespondtochangesinpressureorforceandconvertthesephysicalquantitiesintoadisplacement.Thisdisplacementmaythenbeusedtochangeanelectricalparametersuchasvoltage,resistance,capacitance,orinductance.Suchcombination
4、ofmechanicalandelectricalelementsformelectromechanicaltransducingdevicesorsensor.Similarcombinationcanbemadeforotherenergyinputsuchasthermal.Photo,magneticandchemical,givingthermoelectric,photoelectric,electromaanetic,andelectrochemicalsensorrespectively.2 SensorSensitivityTherelationshipbetweenthem
5、easuredandthesensoroutputsignalisusuallyobtainedbycalibrationtestsandisreferredtoasthesensorsensitivityKl=output-signalincrement/measuredincrement.Inpractice,thesensorsensitivityisusuallyknown,and,bymeasuringtheoutputsignal,theinputquantityisdeterminedfrominput=output-signalincrement/Kl.3 Characteri
6、sticsofanIdealSensorThehighsensorshouldexhibitthefollowingcharacteristics.（八）highfidelity-thesensoroutputwaveformshapebeafaithfulreproductionofthemeasured;thereshouldbeminimumdistortion.(b)Thereshouldbeminimuminterferencewiththequantitybeingmeasured;thepresenceofthesensorshouldnotalterthemeasuredina
7、nyway.(c)Size.Thesensormustbecapableofbeingplacedexactlywhereitisneeded.(d)Thereshouldbealinearrelationshipbetweenthemeasuredandthesensorsignal.(e)Thesensorshouldhaveminimumsensitivitytoexternaleffects,pressuresensor,forexample,areoftensubjectedtoexternaleffectssuchvibrationandtemperature.(f)Thenatu
8、ralfrequencyofthesensorshouldbewellseparatedfromthefrequencyandharmonicsofthemeasurand.Sensorscanbedividedintothefollowingcategories：1 ElectricalSensorElectricalsensorexhibitmanyoftheidealcharacteristics.Inadditiontheyofferhighsensitivityaswellaspromotingthepossibleofremoteindicationormesdurement.El
9、ectricalsensorcanbedividedintotwodistinctgroups:（八）variable-control-parametertypes,whichinclude:(i)resistance(ii)capacitance(iii)inductance(iv)mutual-inductancetypesThesesensorallrelyonexternalexcitationvoltagefortheiroperation.(b)self-generatingtypes,whichinclude(i)electromagnetic(ii)thermoelectric
10、iii)photoemissive(iv)piezo-electrictypesTheseallthemselvesproduceanoutputvoltageinresponsetothemeasurandinputandtheireffectsarereversible.Forexample,apiezo-electricsensornormallyproducesanoutputvoltageinresponsetothedeformationofacrystallinematerial;however,ifanalternatingvoltageisappliedacrossthem
11、aterial,thesensorexhibitsthereversibleeffectbydeformingorvibratingatthefrequencyofthealternatingvoltage.2 ResistanceSensorResistancesensormaybedividedintotwogroups,asfollows:(i)Thosewhichexperiencealargeresistancechange,measuredbyusingpotential-dividermethods.Potentiometersareinthisgroup.(ii)Thosewh
12、ichexperienceasmallresistancechange,measuredbybridge-circuitmethods.Examplesofthisgroupincludestraingaugesandresistancethermometers.3 CapacitiveSensorThecapacitancecanthusmadetovarybychangingeithertherelativepermittivity,theeffectivearea,orthedistanceseparatingtheplates.Thecharacteristiccurvesindica
13、tethatvariationsofareaandrelativepermittivitygivealinearrelationshiponlyoverasmallrangeofspacings.Thusthesensitivityishighforsmallvaluesofd.Unlikethepotentionmeter,thevariable-distancecapacitivesensorhasaninfiniteresolutionmakingitmostsuitableformeasuringsmallincrementsofdisplacementorquantitieswhic
14、hmaybechangedtoproduceadisplacement.4 InductiveSensorTheinductancecanthusbemadetovarybychangingthereluctanceoftheinductivecircuit.Measuringtechniquesusedwithcapacitiveandinductivesensor:（八）A.C.excitedbridgesusingdifferentialcapacitorsinductors.(b)A.C.potentiometercircuitsfordynamicmeasurements.(c)D.
15、C.circuitstogiveavoltageproportionaltovelocityforacapacitor.(d)Frequency-modulationmethods,wherethechangeofCorLvariesthefrequencyofanoscillationcircuit.Importantfeaturesofcapacitiveandinductivesensorareasfollows:(i)resolutioninfinite(ii)accuracy0.1%offullscaleisquoted(iii)displacementranges25*104mto
16、10-3m(iv)risetimelessthan50uspossibleTypicalmeasurandsaredisplacement,pressure,vibration,sound,andliquidlevel.5 LinearVariable-differentialTtransformer6 Piezo-electricSensor7 ElectromagneticSensor8 ThermoelectricSensor9 PhotoelectricCells10 MechanicalSensorandSensingElementsIninformationage,theinfor
17、mationindustryincludesinformationgathering,transmission,processthreeparts,namelysensortechnology,communication,computertechnology.Becauseofultralargescaleintegratedcircuit,srapiddevelopmentafterhavingbeendevelopedModerncomputertechnologyandcommunication,notonlyrequestssensorprecisionreliability,spee
18、dofresponseandgaininformationcontentrequestmoreandmorehighbutalsorequestsitscosttobeinexpensive.Theobvioustraditionalsensoriseliminatedgraduallybecauseofthefunction,thecharacteristic,thevolume,thecostandsoon.Asworlddevelopmanycountriesarespeedinguptothesensornewtechnology,sresearchandthedevelopment,
19、andallhasobtainedtheenormousbreakthrough.Nowthesensornewtechnologydevelopmentmainlyhasfollowingseveralaspects:Usingthephysicalphenomenon,thechemicalreaction,thebiologicaleffectasthesensorprinciplethereforetheresearcheswhichdiscoveredthenewphenomenonandtheneweffectarethesensortechnologicalimprovingwa
20、ys.itisimportantstudiestodevelopednewsensor,sthefoundation.JapaneseSharpCorporationusesthesuperconductivitytechnologytodevelopsuccessfullythehightemperaturesuperconductivitymagneticsensorandgetthesensortechnologysignificantbreakthrough.Itssensitivityissohighandonlyinferiorinthesuperconductivityquant
21、uminterferencecomponent.Itsmanufacturecraftisfarsimplerthanthesuperconductivityquantuminterferencecomponent.Mayuseinmagnetismimageformationtechnology.Soithasthewidespreadpromotedvalue.Usingtheimmunebodyandtheantigenmeetsoneanothercompoundwhentheelectrodesurface.Itcancausetheelectrodepotentialchangea
22、ndusethisphenomenontobepossibletogeneratetheimmunitysensor.Theimmunitysensormakeswiththiskindofimmunebodymaytosomeorganisminwhetherhasthiskindofantoriginalworkinspection.Likemayinspectsomebodywiththehepatitisvirusimmunebodywhethercontractsthehepatitis,playstoisfast,theaccuraterole.TheUSUCsixthbranch
23、hasdevelopedthiskindofsensor.Thesensormaterialistheimportantfoundationforsensortechnology,becausethematerialsscienceisprogressiveandthepeoplemaymakeeachkindofnewsensorForexamplemakingthetemperaturesensorwiththehighpolymerthinfilm;Theopticalfibercanmakethepressure,thecurrentcapacity,thetemperature,th
24、edisplacementandsoonthemanykindsofsensors;Makingthepressuretransmitterwiththeceramics.Thehighpolymercanbecometheproportionadsorptionandthereleasehydrogenalongwiththeenvironmentrelativehumiditysize.Thehighpolymerelectricityliesbetweentheconstanttobesmall,thehydrogencanenhancethepolymerthecoefficiento
25、fdialecticalloss.Makingthecapacitorthehighpolymerdielectricmedium,determinestheelectriccapacitycapecitythechange,thenobtainstherelativehumidity.Makingtheplasmausingthisprincipletogatherthelegitimatepolystyrenefilmtemperaturesensorbelow,ithasthecharacteristic.Measuredthewetscopeiswide;Thetemperaturer
26、angeiswide,mayreach-400+1,500;Thespeedofresponseisquick,issmallerthanIS;Thesizeissmall,mayuseinthesmallspacemeasuringwet;Thetemperaturecoefficientissmall.Theceramicelectriccapacitytypepressuretransmitterisonekinddoesnothavetheintermediaryfluidthedrytypepressuretransmitter.Usestheadvancedceramictechn
27、ology,theheavyfilmelectronictechnology,itstechnicalperformanceisstable,theyeardriftingquantityissmallerthan0.1%F.S,warmfloatsissmallerthan+0.15%10K,anti-overloadsstrongly,mayreachthemeasuringrangeseveralhundredtimes.Thesurveyscopemayfrom0to60mpa.GermanE+HCorporationandtheAmericanKahloCorporationprod
28、uctisattheleadingposition.Theopticalfiberapplicationissendthematerialsignificantbreakthrough,itsusesinmostearlytheopticalcommunicationtechniques.Intheopticalcommunicationusediscoveredworksasenvironmentalconditionchangeandsoonthetemperature,pres-sure,electricfield,magneticfield,causesthefiberoptictra
29、nsmissionlightwaveintensity,thephase,thefrequency,changeandsoonthepolarizationcondition,thesurveylightwavequantitychange,mayknowcausestheselightwavephysicalquantitytheandsoonquantitativechangetemperature,pressure,electricfield,magneticfieldsize,usestheseprinciplestobepossibletodeveloptheopticalfiber
30、sensor.Theopticalfibersensorandthetraditionalsensorcomparehasmanycharacteristics:Sensitivityhigh,thestructuresimple,thevolumesmall,anti-corrosive,theelectricinsulationgood,thepathofraysmaybecurving,beadvantageousfortherealizationtelemeterandsoon.OpticalfibersensorJapanisintheadvancedlevel.LikeIdecIz
31、umiCorporationandSunxCorporation.Theopticalfibersendreceiverandtheintegratedpathofraystechnologyunify,acceleratestheopticalfibersensortechnologydevelopment.Willintegratethepathofray,scomponenttoreplacetheoriginalopticspartandthepassivelightcomponent;enabletheopticalfibersensortohavethehighbandwidth,
32、thelowsignalprocessingvoltage,thereliabilityhigh,thecostwillbelow.Insemiconductortechnologyprocessingmethodoxygenation,thephotoetchang,theproliferation,thedeposition,theplaneelectroncraft,variousguidescorrosionandsteamsplates,thesputteringthinfilmandsoon,thesehaveallintroducedtothesensormanufacture.
33、Thushasproducedeachkindofnewsensor,likemakesthesiliconmicrosensorusingthesemiconductortechnology,makesthefastresponseusingthethinfilmcraftthegastobesensitive,thewetsensitivesensor,theusesputteringthinfilmcraftsystempressuretransmitterandsoon.TheJapanesehorizontalrivercompanyusesvariousguides9corrosi
34、ontechnologytocarryonthehighaccuracythreedimensionalprocessing;thesystemhelpsthesiliconresonancetypepressuretransmitter.ThecorepartiallypressestworesonantLiangbythefeelingwhichabovethesilicondiaphragmandthesilicondiaphragmmanufacturestoform,tworesonantLiang,sfrequencydifferencecorrespondencedifferen
35、tpressure,measuresthepressurewiththefrequencydifferencemethod,mayeliminatetheerrorwhichfactorandsoonambienttemperaturebrings.Whenambienttemperaturechange,tworesonantLiangfrequenciesandtheamplitudevariationaresame,aftertwofrequencydifferences,itssamechangequantitycancounterbalancemutually.It,ssurveym
36、osthighaccuracymayreach0.01%FS.AmericanSiliconMicrostructureInc.(SMI)thecompanydevelopsaseriesoflowends,linearin0.1%to0.In65%scopesiliconmicropressuretransmitter,thelowestfullmeasuringrangeis0.15psi(IKPa),itmakestakethesiliconasthematerial,hastheuniquethreedimensionalstructure,thelightslightmachine-
37、finishing,makesthewheatstonebridgemanytimeswiththeetchingonthesilicondiaphragm,whenabovesiliconchipstress,ithasthedistortion,theresistanceproducespressestheanti-effectbuttolosethebridgebalance,theoutputandthepressurebecomestheproportiontheelectricalsignal.Suchsiliconmicrosensoristhefronttechnologywh
38、ichnowthesensordevelops,Itsessentialfeatureisthesensitiveunitvolumeisamicronmagnitude,Isthetraditionalsensorseveraldozens,several1%.Inaspectandsoonindustrycontrol,aerospacedomain,biomedicinehasthevitalrole,likeontheairplanetheusemayreducetheairplaneweight,reducestheenergy.Anothercharacteristiciscanb
39、esensitiveissmallsurveyed,maymakethebloodpressurepressuretransmitter.TheChineseaviationmaincorporationBeijingobservationandcontroltechnicalresearchinstitute,thedevelopmentCYJseriessplashesthanksthemembranepressuretransmitterisusestheionsputteringcrafttoprocessthemetalstraingauge,ithasovercomethenonm
40、etallicstraingaugeeasilythetemperatureinfluenceinsufficiency,hasthehighstability,issuitableineachkindofsituation,ismeasuredthemediumscopewidely,butalsoovercamethetraditionlowlytogluetheprecisionwhichthetypebrought,sluggishbig,shortcomingandsoonslowchange,hadtheprecisionhigh,there-liabilityishigh,the
41、volumesmallcharacteristic,widelyusedindomainandsoonaviation,petroleum,chemicalindustry,medicalservice.Integratesthesensorthesuperiorityisthetraditionalsensorisunabletoachieve,itisasimplesensornotmerely,itinatthesametimetheauxiliarycircuitpartandsendthepartwillintegrateontogetherthechip,willcauseitto
42、havethecalibration,tocompensate,fromthediagnosisandthenetworkcorrespondencefunction,itmightreducethecost,thegaininyield,thiskindofbloodpressuresensorwhichAmericanLUCAS,NOVASENSORCorporationwilldevelop,eachweekwillbeabletoproduce10,000.Theintellectualizedsensorisonekindofbeltmicroprocessorsensor,isac
43、hievementwhichthemicrocomputerandthesensorunifies,ithasatthesametimetheexamination,thejudgmentandtheinformationprocessingfunction,compareswiththetraditionalsensorhasverymanycharacteristics:Hasthejudgmentandtheinformationprocessingfunction,cancarryontherevision,theerrortotheobservedvaluecompensates,t
44、husenhancementmeasuringaccuracy;Mayrealizethemulti-sensormultiparameterssurvey;Hasfromthediagnosisandfromthecalibrationfunction,enhancesthereliability;Thesurveydatamaydepositandwithdraw,easytooperate;Hasthedatacommunicationinterface,canandthemicrocomputerdirectcommunication.Thesensor,thesignaladjust
45、mentelectriccircuit,themonolithicintegratedcircuitintegrationformsultralarge-scaleintegratedonachiptheseniorintelligencesensor.AmericanHONYWELLCorporationST-3000intelligencesensor,thechipsizeonlythenhas342mm3,usesthesemiconductorcraft,makesCPU,EPROM,thestaticpressure,thedifferentialpressure,thetempe
46、ratureontheidenticalchipandsoonthreekindofsensitiveunits.Theintellectualizedsensorresearchandthedevelopment,USisattheleadingposition.AmericanSpaceAgencywhendevelopmentspaceshipcalledthiskindofsensorforthecleversensor(SmartSensor),onthespaceshipthiskindofsensorisextremelyimportant.Ourcountryinthisasp
47、ectresearchanddevelopmentalsoverybackwardmainlyisbecauseourcountrysemiconductorintegratedcircuittechnologicallevelislimited.Thesensor,sdevelopmentischangingdayafterdaysinceespeciallythe80,shumanitieshaveenteredintothehighindustrializationtheinformationage,sensortechno-logytorenewal,highertechnologic
48、aldevelopment.US,Japanandsoondevelopedcountrysensortechnologicaldevelopmentquickest,ourcountrybecausethefoundationisweak,thesensortechnologycompareswiththesedevelopedcountrieshasthebigdisparity.Therefore,weshouldenlargetothesensorengineeringresearch,thedevelopmentinvestment,causesourcountrysensortec
49、hnologyandtheforeigndisparityreduces,promotesourcountryinstrumentmeasuringapplianceindustryandfromthetechnicaldevelopment.FromSensorTechnologyHandbook,JonWilson9Newnes传感器新技术的开展传感器是一种能将物理量、化学量、生物量等转换成电信号的器件。输出信号有不同形式，如电压、电流、频率、脉冲等，能满足信息传输、处理、记录、显示、控制要求，是自动检测系统和自动控制系统中不可缺少的元件。如果把计算机比作大脑，那么传感器那么相当于五官，传感器能正确感受被测量并转换成相应输出量，对系统的质量起决定性作用。自动化程度越高，系统对传感器要求越高。传感器的几个关键词：1传感器元件除特例外，大多数的传感器都由敏感元件、转换元件或控制元件组成。如振动膜、波纹管、应力管和应力环、低音管和悬臂都是敏感元件，它们对压力和力作出响应把物理量
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