熱敏電阻介紹課件

IntroductionofThermistorAlipChenMarch152011ConceptDefinition:Thermistor:thermallysensitiveresistorApplication:TemperatureDetector,Control,Switch,Fuse…Catalog:NTC,PTC,RTD,…NTC:NegativeTemperatureCoefficientResistorPTC:PositiveTemperatureCoefficientResistorRTD:ResistanceTemperatureDetectorResistanceTemperatureDetectorType

ElementMaterial

BaseResistance(Ohms)

TCR(Ohm/Ohm/C)

BaseResistanceTolerance+/-

TCRTolerance%

CBCOPPER10OHMSAT25C.004270.2%1%CCCOPPER10OHMSAT25C.004270.5%1%NANICKEL120OHMSAT0C.006720.5%1%PAPLATINUM100OHMSAT0C.003850.06%0.12%PBPLATINUM100OHMSAT0C.003850.12%0.35%

PCPLATINUM100OHMSAT0C.003850.5%1%PEPLATINUM100OHMSAT0C.003910.12%0.35%PFPLATINUM100OHMSAT0C.003910.5%1%PGPLATINUM100OHMSAT0C.003750.12%0.35%PHPLATINUM100OHMSAT0C.003920.5%0.1%Type:WireWound,ThinFilmMaterial:Pt,Cu,NiPrinciple:R-TeffectSample:seephotosTypicalperformance:SeebelowtableFeatures:accuracy,linearThermocoupleType:K,E,J,N,B,R,SMaterial:Pt–Rhodium,W-Rhenium,Constantan,CupronPrinciple:SeebeckeffectthatthejunctionbetweentwometalsgeneratesavoltagewhichisafunctionoftemperatureTypicalperformance:SeebelowtableFeatures:interchangeable,widerangeoftemperaturesThermocoupletypeOverallrange°CsensitivityB(Platinum/Rhodium)

20to182010μV/°CE(Chromel/Constantan)

-270to91068μV/°CJ(Iron/Constantan)-210to1200

50μV/°CK(Chromel/Alumel)-270to137041μV/°CN(Nicrosil/Nisil)-270to130010μV/°CR(Platinum/Rhodium)

-50to176010μV/°CS(Platinum/Rhodium)

-50to176010μV/°CT(Copper/Constantan)-270to40060μV/°CDegC02468-20-0.995-1.093-1.19-1.288-1.385-10-0.501-0.6-0.699-0.798-0.89600-0.101-0.201-0.301-0.401DegC02468000.1010.2020.3030.405100.5070.6090.7110.8130.916201.0191.1221.2251.3291.432TypeJ:V(mV)/T(C)TableNTCType:disc,rod,chipMaterial:Ceramic(Mn,Fe,Co,Ni,Znetc,transitionmetaloxides)Principle:R-TeffectSamples:Seephoto:EpoxyandGlassPKG.Typicalperformance:SeebelowtableFeatures:Cheap,highsensitivity,smallsizeNTCParameterZero-PowerResistance(R0):R0isthemeasuredDC(directcurrent)resistanceataspecifictemperatureTwhenthepowerdissipationisnegligible.Generallyconsiderthepowertobenegligiblewhenanydecreaseinpowerwillresultinnotmorethana0.1%changeinresistance.Alpha(α)(Temperaturecoefficient):Alpha,amaterialcharacteristic,isdefinedasthepercentageresistancechangeperdegreecentigrade.ForNTCthermistor,typicalvalueofalphaareintherangeof-3%Cto-6%C.Betavalue(β):Bvaluecanberegardedaquantitativevalueofthermistormaterialsthatisassignedasamaterialconstantandthatindicatestherelationshipofmaterialresistivitytotemperature.NTCParameterTolerance:Toleranceforthermistoristhespecifiedresistancepercentageortemperaturedeviationfromcurvenominalvalues.ThermalTimeConstant:Itisthetimerequiredforathermistortochangeitsbodytemperatureby63.2%ofaspecifiedtemperaturespanwhenthemeasurementaremadeunderzero-powerconditionsinthermallystableenvironment.ThermalDissipationConstant:Itisdefinedasthepowerrequiredtoraisethethermistor’sbodytemperatureby1°Cinaparticularmeasurementmedium.Itsunitsisexpressedintheunitofmw/°C.RatingPower:Itisspecifiedasth