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sensor20110910王鹏举Livinginarapidlydevelopingsociety，wehavethechancetoenjoymanythingspeoplewhohasdiedcannot.SomeonemaylikesmartcarsSomeonemaybepureMilitaryenthusiastsButeverymachinecannotworkwithoutmanyspecialdevicesinit.Thesespecialdevicesarecalled“transducer”or“sensor”,whicharewidelyusedineverywhere.Sensorstomachineiswhatsenseorganstoapeople.Lotssensorsmakeupthenervoussystemofthemachine,thenthemachinecanbecontrolledbypeopletodowhattheywant.Now,let’shavearealizationonthedifferentsensesofmachine.PhotosensitivesensorAcousticsensorsGassensorchemicalsensorPressure,temperature,fluidsensorPhotosensitivesensor(光敏传感器)Photosensitivesensorisoneofthemostcommonsensor,itssortisvarious,mainlyinclude:photocell(光电管),photomultipliertubes（光电倍增管）,photosensitiveresistance（光敏电阻）,lightactivatedtriode（光敏三极管）,solarcells（太阳能电池）andinfraredsensors（红外线传感器）,ultraviolet[ʌltrə‘vaɪələt]sensors（紫外线传感器）,optical[’ɒptɪk(ə)l]fibertypephotoelectricsensor（光纤式光电传感器）,colorsensor,CCDandCMOSimagesensor,etc.•Lightsensoristhemostcurrentproduction,oneofthemostwidelyusedsensors,itplaysanimportantroleinautomaticcontrol(自动控制)andnon-electricitymeasurement[‘meʒəm(ə)nt]technology（非电量电测技术）.Thesimplestphotosensitivesensorisphotosensitiveresistance(光敏电阻),itwillcreateelectriccurrentwhenphotons（光子）hitjoint（结合处）.Workingprinciple•Lightsensorscanconvertslightsignalsintoelectricalsignalswithphotosensitiveelementsensor,itssensitivewavelengthsisclosetothevisiblelightwavelength,includinginfrared[ɪnfrə'red]wavelength（红外线波长）andultraviolet[ʌltrə'vaɪələt]wavelengths（紫外线波长）.Lightsensorisnotlimitedtolightdetection,italsocanbeusedasadetectiondeviceofothersensorstotestmanynon-electrical,aslongasthenon-electriccanbeconvertedintoopticalsignalchanges（光信号变化）.Application•Photosensitivesensorismainlyusedinsolarenergylawnlamp(太阳能草坪灯),smallopticalnightlights（光学小夜灯）,camera,monitors[‘mɑnətɚ],electrictoys,electricswitches,anti-theftwallet,electricmusicbox,musicbirthdaycandle,musiccup,thebodyinduction（感应）switch,andotherlightautomaticcontrolfield.backAcousticsensors(声敏传感器)•Workingprinciple•Thesensorissensitivetoabuilt-intosoundcapacitive[kə'pæsɪtɪv]electretmicrophone（电容式驻极话筒）.Soundwavesmakethemicrophoneelectretfilm（驻极体膜）vibration[vaɪ'breɪʃ(ə)n],resultinthechangeofcapacitance[kə'pæsɪt(ə)ns],andproducewiththecorrespondingchangeoftinyvoltage['vəʊltɪdʒ;'vɒltɪdʒ].Thenthisvoltageisconvertedinto0to5voltage,andtransmittedtothecomputer,afterA/Dconversionwasacceptedbythedatacollector.Aplication•A.thesensordoesnotneedtocheckitagain,thesoftwarezero（调零）automatically.•B.sampling['sɑːmplɪŋ]frequencymustreach10000timespersecondormore,otherwise，it’snottrueandaccuratetoreflecttheimageofacousticvibration.•C.ycoordinate[kəu'ɔ:dinit,kəu'ɔ:dineit]oftheimagerepresentsthevoltagevaluecorrespondingtoacousticvibration.•D.whencostlimited,manufacturerscanusepositiveandnegativesignaloutput,suchas:TZ–2KAandsoon.backGassensor气敏传感器•Workingprinciple•Thewavevelocity[vɪ‘lɒsɪtɪ]andfrequencyofsurfaceacousticwave(声表面波)deviceswilldriftalongwith（漂移）thechangeofexternalenvironment.Gassensorstakeadvantageofthisperformanceinthepiezoelectric[piː,eɪzəʊɪ’lektrɪk]crystal[‘krɪst(ə)l]surface(压电晶体表面)coated[’kəʊtɪd]withalayerofgassensitivefilm,makinggassensitivefilmmembrane[‘membreɪn]layermassandconductivity(导电性)change,causingthesurfaceacousticwave（声表面波）frequencyofapiezoelectriccrystaldrift;Application•Gassensorapplicationsare:carbonmonoxide[mə'nɒksaɪd]gasdetection(一氧化碳气体检测),mash（瓦斯）gasdetection,coalgas（煤气）detection,detectionofalcoholinhumanbreathandsoon.Itcanconvertstheinformationaboutthetypeanddensity(密度)ofgasintoelectricalsignals.Accordingtothestrengthoftheseelectricalsignals,itcangaintheinformationassociatedwithgascompositionusingtodetect,monitor,alarm.backChemicalsensor化学传感器Aplicationofchemicalsensor•Chemicalsensorsisusedforchemicalmeasurements.Itisoftenusedintheproductionprocessanalysisandenvironmentalpollutionmonitoring.Chemicalsensorhasbeenwidelyusedinmineralresourcesexploration（矿产资源探索）,weatherobservation(气象观测)andremotesensing（遥测）,industrialautomation（工业自动化）,medicaldiagnosis[,daɪəg'nəʊsɪs]（医疗诊断）andreal-timeremotemonitoring（实时监测）,agriculturefreshpreservationandfishdetection,security,securityalarm,andenergysavingandsoon.backPressuresensitive,temperature,fluidsensor,senseoftouch•Pressuresensoristhemostcommonsensorinindustrialpractice,itiswidelyusedinvariousindustrialcontrolenvironment(工业自控环境),involvingwaterconservancyandhydropower['haɪdrə(ʊ)paʊə]（水利水电）,railwaytransportation,intelligentbuildings,productioncontrol（生产自控）,aerospace,military['mɪlɪt(ə)rɪ]industry（军工）,petrochemical（石化）,oil,electricpower,ships,machinetools（机床）,pipe,andmanyotherindustries.Thanks!