溫度傳感器temperaturesensor車輛檢測技術(shù)V

鄭州鐵路職業(yè)技術(shù)學(xué)院溫度傳感器temperaturesensor車輛檢測技術(shù)Vehicledetectiontechnology主講人：時(shí)蕾FUNDAMENTALSOFSENSORTECHNOLOGYLecturer:ShiLei任務(wù)五溫度傳感器temperaturesensor01熟悉溫度傳感器的工作原理Familiarwiththeworkingprincipleoftemperaturesensor02認(rèn)識(shí)溫度傳感器Understandingtemperaturesensor03學(xué)會(huì)分析溫度傳感器的應(yīng)用Learntoanalyzetheapplicationoftemperaturesensors學(xué)習(xí)目標(biāo)/LEARNINGGOALS目錄CATALOGPART

01了解溫度傳感器UnderstandingtemperaturesensorsPART

02金屬熱電阻MetalthermistorPART

03熱敏電阻thermistorPART

04紅外線傳感器infraredsensor了解溫度傳感器UnderstandingtemperaturesensorsPart

01車輛檢測技術(shù)Vehicledetectiontechnology了解溫度傳感器一、了解溫度傳感器

Understandingtemperaturesensors因此，人類離不開溫度，當(dāng)然也離不開溫度傳感器。Therefore,humanbeingscannotlivewithouttemperature,andofcoursecannotlivewithouttemperaturesensors.溫度是反映物體冷熱狀態(tài)的物理參數(shù)。Temperatureisaphysicalparameterthatreflectsthecoldandhotstateofanobject.溫度是與人類生活息息相關(guān)的物理量。在2000多年前，就開始為檢測溫度進(jìn)行了各種努力，并開始使用溫度傳感器檢測溫度。人類社會(huì)中，工業(yè)、農(nóng)業(yè)、商業(yè)、科研、國防、醫(yī)學(xué)及環(huán)保等部門都與溫度有著密切的關(guān)系。工業(yè)生產(chǎn)自動(dòng)化流程,溫度測量點(diǎn)要占全部測量點(diǎn)的一半左右。Temperatureisaphysicalquantitycloselyrelatedtohumanlife.Morethan2,000yearsago,variouseffortstodetecttemperaturebegan,andtemperaturesensorsbegantobeusedtodetecttemperature.Inhumansociety,industry,agriculture,commerce,scientificresearch,nationaldefense,medicineandenvironmentalprotectionandothersectorshaveacloserelationshipwithtemperature.Intheindustrialproductionautomationprocess,thetemperaturemeasurementpointsshouldaccountforabouthalfofthetotalmeasurementpoints.1.溫度傳感器temperaturesensor指能感受溫度并轉(zhuǎn)換成可用輸出信號(hào)的傳感器。Asensorthatsensestemperatureandconvertsitintoausableoutputsignal.在種類繁多的傳感器中，溫度傳感器實(shí)現(xiàn)溫度檢測控制和的重要器件。是應(yīng)用最廣泛發(fā)展最快溫度傳感器是的傳感器之一。了解溫度傳感器Temperaturesensoristheimportantdeviceofrealizetemperaturedetectionandcontrol.Inawidevarietyofsensors,temperaturesensorisoneofthemostwidelyusedand

rapidlydevelopingsensors.

1.溫度傳感器temperaturesensor指能感受溫度并轉(zhuǎn)換成可用輸出信號(hào)的傳感器。Asensorthatsensestemperatureandconvertsitintoausableoutputsignal.在種類繁多的傳感器中，溫度傳感器實(shí)現(xiàn)溫度檢測控制和的重要器件。是應(yīng)用最廣泛發(fā)展最快溫度傳感器是的傳感器之一。了解溫度傳感器了解溫度傳感器溫度感溫元件轉(zhuǎn)換電路溫度顯示溫度傳感器的組成框圖溫度不能直接測量，需要借助于某種物體的物理參數(shù)隨溫度冷熱不同而明顯變化的特性進(jìn)行間接測量。Temperaturecannotbemeasureddirectly,needtorelyonthephysicalparametersofanobjectwiththetemperatureofthecoldandhotandobviouschangesinthecharacteristicsofindirectmeasurement.溫度傳感器就是通過測量某些物理量參數(shù)隨溫度的變化而間接測量溫度的。Temperaturesensoristomeasurethetemperatureindirectlybymeasuringthechangeofsomephysicalparameterswiththetemperature.溫度傳感器是由溫度敏感元件（感溫元件）和轉(zhuǎn)換電路組成的。Thetemperaturesensoriscomposedofatemperaturesensingelement(temperaturesensingelement)andaconversioncircuit溫度傳感器的工作原理Howthetemperaturesensorworks01temperaturetemperature-sensingelementswitchingcircuittemperaturedisplayBlockdiagramoftemperaturesensor按測量方式分類Classificationbymeasurement了解溫度傳感器非接觸式non-contact不與被測物體接觸，不破壞原有的溫度場，精度一般不高。Doesnotcontactwiththemeasuredobject,doesnotdestroytheoriginaltemperaturefield,theaccuracyisgenerallynothigh.接觸式

contact

直觀、可靠、測量儀表比較簡單。Intuitive,reliable,simplemeasuringinstrument紅外線輻射溫度計(jì)的使用溫度傳感器的分類Classificationoftemperaturesensors02了解溫度傳感器特點(diǎn)

characteristic不需要電源，耐用；但感溫部分體積比較大。Nopowerrequired,durable;Butthevolumeofthetemperaturesensingpartislarger.特點(diǎn)

characteristic自發(fā)電型，結(jié)構(gòu)簡單，機(jī)械強(qiáng)度高，測溫范圍寬，精度高。需注意冷端溫度補(bǔ)償。Self-electrictype,simplestructure,highmechanicalstrength,widetemperaturemeasurementrange,highprecision.Payattentiontocoldendtemperaturecompensation.氣體膨脹式溫度計(jì)Gasexpansionthermometer溫度傳感器的特點(diǎn)Characteristicsoftemperaturesensor03了解溫度傳感器特點(diǎn)

characteristic靈敏度高,穩(wěn)定性強(qiáng),互換性以及準(zhǔn)確性都會(huì)比較好,但是需要電源的激勵(lì),不能夠瞬時(shí)地測量溫度的變化。Highsensitivity,strongstability,interchangeabilityandaccuracywillbebetter,buttheexcitationofthepowersupplyisrequired,andthetemperaturechangecannotbemeasuredinstantaneously.特點(diǎn)

characteristic面積大，可得到溫度圖像，但易衰老，精度低。Theareaislarge,andthetemperatureimagecanbeobtained,butitiseasytoageandtheaccuracyislow.熱電阻傳感器Thermalresistancesensor示溫涂料thermo-color了解溫度傳感器紅外輻射溫度計(jì)infraredradiationthermometer紅外線光子探頭Infraredphotonprobe特點(diǎn)非接觸式測量，反應(yīng)快；但易受環(huán)境及被測體表面狀態(tài)影響，標(biāo)定困難。Non-contactmeasurement,fastresponse;However,itiseasytobeaffectedbytheenvironmentandthesurfacestateofthemeasuredbody,sothecalibrationisdifficult.光敏電阻photoresistor了解溫度傳感器是利用導(dǎo)體或半導(dǎo)體的電阻值隨溫度變化而變化的原理進(jìn)行測溫的。用金屬或半導(dǎo)體材料作為感溫元件的傳感器，分別稱為金屬熱電阻和熱敏電阻。Thetemperatureismeasuredusingtheprinciplethattheresistancevalueofaconductororsemiconductorchangeswiththetemperature.Sensorsthatusemetalorsemiconductormaterialsastemperaturesensingelementsarecalledmetalthermistorsandthermistors,respectively.2.熱電阻傳感器Thermalresistancesensor熱電阻傳感器分為金屬熱電阻和半導(dǎo)體熱電阻兩大Thethermalresistancesensorisdividedintometalthermalresistanceandsemiconductorthermalresistance熱電阻熱敏電阻而把半導(dǎo)熱電阻廣泛用來測量-200℃～850℃范圍內(nèi)的溫度，少數(shù)情況下，低溫可測量至1K，高溫達(dá)1000℃。Thermalresistanceiswidelyusedtomeasurethetemperatureintherangeof-200℃~850℃,inafewcases,lowtemperaturecanbemeasuredto1K,hightemperatureupto1000℃熱電阻傳感器由熱電阻、連接導(dǎo)線及顯示儀表組成。Thethermalresistancesensoriscomposedofthermalresistance,connectingwireanddisplayinstrument熱電阻也可與溫度變送器連接，轉(zhuǎn)換為標(biāo)準(zhǔn)電流信號(hào)輸出。Thethermalresistancecanalsobeconnectedtoatemperaturetransmitterandconvertedintoastandardcurrentsignaloutput.類，一般把金屬熱電阻稱為體熱電阻稱為Generally,themetalthermalresistanceiscalledthethermalresistanceandthesemiconductingBodyheatresistanceiscalledthermistor金屬熱電阻MetalthermistorPart

02車輛檢測技術(shù)Vehicledetectiontechnology金屬熱電阻二、金屬熱電阻

Metalthermistor認(rèn)識(shí)金屬熱電阻Understandingmetalthermalresistance01取一只100W/220V燈泡，用萬用表測量其電阻值，可以發(fā)現(xiàn)其冷態(tài)阻值只有幾十歐姆，而計(jì)算得到的額定熱態(tài)電阻值應(yīng)為484Ω

。

Takea100W/220Vbulbandmeasureitsresistancevaluewithamultimeter,youcanfindthatitscoldresistancevalueisonlytensofohms,andthecalculatedratedhotresistancevalueshouldbe484Ω.熱電阻的主要技術(shù)性能Themaintechnicalpropertiesofthermalresistance金屬熱電阻易提純、復(fù)現(xiàn)性好的金屬材料才可用于制作熱電阻Metalmaterialsthatareeasytopurifyandhavegoodreproducibilitycanbeusedtomakethermalresistors（1）金屬熱電阻鉑熱電阻

platinumthermistor鉑電阻溫度計(jì)的使用范圍是-200℃～850℃。Theuserangeofplatinumresistancethermometeris-200℃~850℃.

例如

電阻比W(100)越大，其純度越高。按IEC標(biāo)準(zhǔn)，工業(yè)使用的鉑熱電阻的W(100)≥1.3850。目前技術(shù)水平可達(dá)到W(100)=1.3930，其對(duì)應(yīng)鉑的純度為99.9995%。一般情況下，工業(yè)鉑熱電阻由直徑為0.03mm～0.07mm的純鉑絲繞在平板形支架，用銀線作為引出線。ThehighertheresistanceratioW(100),thehigheritspurity.AccordingtoIECstandards,theW(100)ofplatinumthermalresistanceusedinindustryis≥1.3850.Atpresent,thetechnicallevelcanreachW(100)=1.3930,andthecorrespondingplatinumpurityis99.9995%.Undernormalcircumstances,theindustrialplatinumthermistorconsistsofapureplatinumwirewithadiameterof0.03mm~0.07mmwrappedaroundaflat-shapedbracket,andasilverwireisusedastheleadwire.鉑熱電阻中的鉑絲純度用電阻比W(100)表示，即PlatinumwirepurityinplatinumthermalresistanceisexpressedbyresistanceratioW(100),thatis金屬熱電阻鉑是一種貴金屬。它的特點(diǎn)是精度高，穩(wěn)定性好，性能可靠，尤其是耐氧化性能很強(qiáng)。Platinumisapreciousmetal.Itischaracterizedbyhighprecision,goodstability,reliableperformance,especiallystrongoxidationresistance.鉑電阻的電阻溫度系數(shù)比較??；Theresistancetemperaturecoefficientofplatinumresistanceisrelativelysmall鉑在很寬的溫度范圍內(nèi)約1200℃以下都能保證上述特性。鉑很容易提純，復(fù)現(xiàn)性好，有良好的工藝性，可制成很細(xì)的鉑絲(0.02mm或更細(xì))或極薄的鉑箔。與其它材料相比，鉑有較高的電阻率，因此普遍認(rèn)為是一種較好的熱電阻材料。Platinumcanguaranteetheabovecharacteristicsinawidetemperaturerangeofabout1200°C.Platinumiseasytopurify,hasgoodreproducibility,hasgoodprocessability,canbemadeintoveryfineplatinumwire(0.02mmorthinner)orverythinplatinumfoil.Comparedwithothermaterials,platinumhasahigherresistivity,soitisgenerallyconsideredtobeabetterthermalresistancematerial.價(jià)格貴

highprice優(yōu)點(diǎn)

advantage缺點(diǎn)

drawback薄膜型及普通型鉑熱電阻Thinfilmandordinaryplatinumthermistors金屬熱電阻小型鉑熱電阻Smallplatinumthermalresistance金屬熱電阻鉑電阻溫度顯示、變送器Platinumresistancetemperaturedisplay,transmitter金屬熱電阻（2）金屬熱電阻銅熱電阻

Copperthermistor

銅熱電阻的電阻溫度系數(shù)比鉑高，電阻與溫度的關(guān)系(R-t)曲線幾乎是線性的，并且銅價(jià)格便宜、易于提純、工藝性好。因此，在一些測量精度要求不高、測溫范圍不大且溫度較低的測溫場合，可采用銅熱電阻進(jìn)行測溫。在-50℃～100℃的使用范圍內(nèi)其電阻值與溫度的關(guān)系幾乎是線性的。Theresistancetemperaturecoefficientofcopperthermalresistanceishigherthanthatofplatinum,therelationshipbetweenresistanceandtemperature(R-t)curveisalmostlinear,andcopperischeap,easytopurifyandgoodtechnology.Therefore,insomemeasuringaccuracyrequirementsarenothigh,thetemperaturerangeisnotlargeandthetemperatureislow,copperthermalresistancecanbeusedfortemperaturemeasurement.Intherangeof-50℃~100℃,therelationshipbetweentheresistancevalueandtemperatureisalmostlinear.金屬熱電阻汽車用水溫傳感器及水溫表Watertemperaturesensorandwatertemperaturemeterforautomobile銅熱電阻Copperthermistor金屬熱電阻金屬熱電阻的結(jié)構(gòu)Structureofmetalthermalresistance02工業(yè)用金屬熱電阻由熱電阻體、引出線、絕緣骨架、保護(hù)套管、接線盒等部分組成。熱電阻的電阻體由電阻絲和電阻支架組成。Industrialmetalthermalresistanceiscomposedofthermalresistancebody,leadwire,insulationframe,protectivesleeve,junctionboxandsoon.Theresistancebodyofthethermalresistanceiscomposedofresistancewireandresistancebracket.電阻絲采用雙線無感繞法繞制在一定形狀的云母、石英或陶瓷塑料支架上，支架起支撐和絕緣作用，引出線通常采用直徑1mm的銀絲或鍍銀銅絲，它與接線盒柱相接，以便與外接線路相連而測量及顯示溫度。Theresistancewireiswoundonacertainshapeofmica,quartzorceramicplasticbracketbydouble-wirenon-inductivewinding.Thebracketplaysasupportingandinsulatingrole.Theleadwireisusuallysilverwireorsilver-platedcopperwirewithadiameterof1mm,whichisconnectedwiththejunctionboxcolumntomeasureanddisplaythetemperature.（1）金屬熱電阻金屬熱電阻的應(yīng)用電路Applicationcircuitofmetalthermalresistance03金屬熱電阻廣泛的應(yīng)用

Metalthermalresistanceiswidelyused在軸瓦、缸體、油管、汽管、紡機(jī)、空調(diào)、熱水器等狹小空間工業(yè)設(shè)備測溫和控制。汽車空調(diào)、冰箱、冷柜、飲水機(jī)、咖啡機(jī)、烘干機(jī)以及中低溫干燥箱、恒溫箱等場合也經(jīng)常采用。Inthebearing,cylinder,oilpipe,steampipe,spinningmachine,airconditioning,waterheaterandothersmallspaceindustrialequipmenttemperaturecontrol.Automobileairconditioning,refrigerator,freezer,waterdispenser,coffeemachine,dryerandlowtemperaturedryingbox,thermostatandotheroccasionsareoftenused.金屬熱電阻的連接法

Connectionmethodofmetalthermalresistance用熱電阻傳感器進(jìn)行測溫時(shí)，

Whenmeasuringtemperaturewithathermalresistancesensor,熱電阻與檢測儀表相隔一段距離，因?yàn)闊犭娮璧囊€對(duì)測量結(jié)果有較大的影響，所以測量電路經(jīng)常采用電橋電路。Thethermalresistanceandthedetectioninstrumentareseparatedbyadistance,becausetheleadofthethermalresistancehasagreaterimpactonthemeasurementresult,sothemeasurementcircuitoftenusesthebridgecircuit.可采用三線或四線電橋連接法。

Threeorfourwirebridgeconnectionmethodcanbeused.說明

explain金屬熱電阻三線制

three-wiresystem

圖6—8熱電阻的三線制接法原理圖Figure6-8Schematicdiagramofthree-wireconnectionofthermalresistance用于工業(yè)測量，一般精度Forindustrialmeasurement,generalaccuracy說明

explain金屬熱電阻四線制

four-wiresystem回路中要采用線性好的恒流源，依靠電路結(jié)構(gòu)可以完全消除測量誤差,比三線制精度更高,可用于計(jì)量和化工科研單位,可以作為溫場記錄等。Thecircuitshoulduseagoodlinearconstantcurrentsource,relyingonthecircuitstructurecancompletelyeliminatethemeasurementerror,higherprecisionthanthethree-wiresystem,canbeusedformeasurementandchemicalresearchunits,canbeusedastemperaturefieldrecords.實(shí)驗(yàn)室用，高精度測量Highprecisionmeasurementforlaboratoryuse圖6-9熱電阻的四線制接法原理圖Figure6-9Schematicdiagramofthefour-wireconnectionofthethermalresistor右圖是一個(gè)熱電阻流量計(jì)的原理圖。兩個(gè)鉑電阻探頭Rt1、Rt2

，Rt1放在管道中央，它的散熱情況受介質(zhì)流速的影響。Rt2放在溫度與流體相同，但不受介質(zhì)流速影響的小室中。Thediagramontherightisaschematicdiagramofathermalresistanceflowmeter.TwoplatinumresistanceprobesRt1,Rt2,Rt1inthemiddleofthepipeline,itsheatdissipationisaffectedbytheflowrateofthemedium.Rt2isplacedinachamberthathasthesametemperatureasthefluidbutisnotaffectedbytheflowrateofthemedium.當(dāng)介質(zhì)處于靜止?fàn)顟B(tài)時(shí)電橋處于平衡狀態(tài)，流量計(jì)沒有指示。WhenthemediumisatrestThebridgeisinequilibriumandtheflowmeterisnotindicating.當(dāng)介質(zhì)流動(dòng)時(shí)由于介質(zhì)流動(dòng)帶走熱量，溫度的變化引起阻值變化，電橋失去平衡而有輸出，電流計(jì)的指示直接反映了流量的大小。WhenthemediumflowsBecausethemediumflowtakesawaytheheat,thechangeoftemperaturecausestheresistancevaluetochange,thebridgeisoutofbalanceandhastheoutput,theammeterindicationdirectlyreflectsthesizeoftheflow金屬熱電阻金屬熱電阻的應(yīng)用電路Applicationcircuitofmetalthermalresistance04熱電阻式流量計(jì)

Thermalresistanceflowmeter（1）熱敏電阻thermistorPart

03車輛檢測技術(shù)Vehicledetectiontechnology等特點(diǎn)得到廣泛地應(yīng)用。

Thesecharacteristicshavebeenwidelyused熱敏電阻因其電阻溫度系數(shù)大，靈敏度高；熱慣性小，反應(yīng)速度快；體積小，結(jié)構(gòu)簡單；使用方便，壽命長，易于實(shí)現(xiàn)遠(yuǎn)距離測量Thermistorhashighsensitivitybecauseofitslargeresistancetemperaturecoefficient.Thethermalinertiaissmall,thereactionspeedisfast;Smallsize,simplestructure;Easytouse,longlife,easytoachieveremotemeasurement熱敏電阻是一種利用半導(dǎo)體制成的敏感元件，其特點(diǎn)是電阻率隨溫度而顯著變化。Athermistorisasensitiveelementmadeofsemiconductors,whichischaracterizedbyasignificantchangeinresistivitywithtemperature.三、熱敏電阻

thermistor認(rèn)識(shí)熱敏電阻Understandingthermistors01在溫度變化相同時(shí)，熱敏電阻的阻值變化約為鉑熱電阻的10倍，因此可以用它來測量0.01℃或更小的溫度差異。Withthesametemperaturechange,theresistancevalueofathermistorchangesabout10timesasmuchasaplatinumthermistor,soitcanbeusedtomeasureatemperaturedifferenceof0.01°Corless.熱敏電阻熱敏電阻(珠形）高精度負(fù)溫度系數(shù)熱敏電阻（Bead)Highprecisionnegativetemperaturecoefficientthermistor熱敏電阻MF55薄膜型熱敏電阻MF73大功率型熱敏電阻

WMZ71/72/73消磁型PTC熱敏電阻測溫型正溫系數(shù)WMZ58熱敏電阻器玻璃封裝MF55thinfilmthermistorMF73HighpowerthermistorWMZ71/72/73DegaussingtypePTCthermistor熱敏電阻熱敏電阻的電阻－溫度特性Resistance-temperaturecharacteristicsofthermistors02NTCPTCCTR負(fù)溫度系數(shù)熱敏電阻，溫度越高，阻值越小，且有明顯的非線性。最常見的是由金屬氧化物組成的，如錳，鈷，鐵，鎳，銅等多種氧化物混合燒結(jié)而成。NTC熱敏電阻具有很高的負(fù)電阻溫度系數(shù)，特別適用于：－100～＋300℃之間測溫。廣泛應(yīng)用于需要定點(diǎn)測溫的自動(dòng)控制電路中，如冰箱，空調(diào)等。Negativetemperaturecoefficientthermistor,thehigherthetemperature,thesmallertheresistancevalue,andthereisanobviousnonlinear.Themostcommoniscomposedofmetaloxides,suchasmanganese,cobalt,iron,nickel,copperandotheroxidesmixedandsintered.NTCthermistorshaveahighnegativeresistancetemperaturecoefficientandareespeciallysuitablefortemperaturemeasurementbetween-100and+300°C.Itiswidelyusedinautomaticcontrolcircuitsthatrequirefixedpointtemperaturemeasurement,suchasrefrigerators,airconditioners,etc.正溫度系數(shù)，BaTiO3（鈦酸鋇）系列材料制成熱敏電阻的阻值隨溫度升高而增大，且有斜率最大的區(qū)域，當(dāng)溫度超過某一數(shù)值時(shí)，其電阻值朝正的方向快速變化。其用途主要是彩電消磁、各種電器設(shè)備的過熱保護(hù)等。Positivetemperaturecoefficient:TheresistancevalueofthethermistormadeofBaTiO3(bariumtitanate)seriesmaterialsincreaseswiththeincreaseoftemperature,andthereisaregionwiththelargestslope.Whenthetemperatureexceedsacertainvalue,theresistancevaluechangesrapidlyinthepositivedirection.ItsmainuseiscolorTVdegaussing,variouselectricalequipmentoverheatingprotection也具有負(fù)溫度系數(shù)，VO3（氧化釩）系列材料制作，但在某個(gè)溫度范圍內(nèi)電阻值急劇下降，曲線斜率在此區(qū)段特別陡，靈敏度極高。主要用作溫度開關(guān)。Italsohasanegativetemperaturecoefficient,madeofVO3(vanadiumoxide)seriesmaterials,buttheresistancevaluedropssharplyinacertaintemperaturerange,theslopeofthecurveisparticularlysteepinthissection,andthesensitivityisextremelyhigh.Mainlyusedasatemperatureswitch各種熱敏電阻的阻值在常溫下很大，不必采用三線制或四線制接法，給使用帶來方便。Theresistancevalueofvariousthermistorsisverylargeatroomtemperature,anditisnotnecessarytousethree-wireorfour-wireconnectionmethod,whichbringsconveniencetouse熱敏電阻熱敏電阻的電阻－溫度特性曲線Resistance-temperaturecharacteristicofathermistor熱敏電阻熱敏電阻的應(yīng)用Theapplicationofthermistors03溫度控制

temperaturecontrol（1）PTC溫控PTC熱敏電阻利用PTC熱敏電阻器在居里溫度以上電阻值陡然升高的特性，當(dāng)環(huán)境溫度異常升高時(shí)，裝有PTC熱敏電阻器的保護(hù)線路通過阻值的改變而接通或斷開回路，達(dá)到溫度控制的目的。TemperaturecontrolPTCthermistorusesthecharacteristicthattheresistancevalueofPTCthermistorrisesabruptlyabovetheCurietemperature.Whentheambienttemperaturerisesabnormally,theprotectionlineequippedwithPTCthermistorisswitchedonoroffbychangingtheresistancevaluetoachievethepurposeoftemperaturecontrolWMZ6

過熱保護(hù)型熱敏電阻

熱敏電阻熱敏電阻用于CPU的溫度測量ThethermistorisusedtomeasurethetemperatureoftheCPU熱敏電阻熱敏電阻用于電熱水器的溫度控制Thermistorsareusedfortemperaturecontrolofelectricwaterheaters熱敏電阻熱敏電阻體溫表

Thermistorthermometer（2）電子體溫計(jì)electronicthermometer熱敏電阻電動(dòng)機(jī)過載或缺相保護(hù)

Motoroverloadorphaselossprotection（3）RtaRtbRtc熱敏電阻(NTC)，安裝在三相繞組附近Thermistor(NTC),installednearthethree-phasewinding溫度低時(shí)Atlowtemperature電阻高三極管不導(dǎo)通繼電器不吸合電機(jī)運(yùn)行Highresistancetriodenoonrelaydoesnotdrawmotoroperation溫度高時(shí)Athightemperature電阻低三極管導(dǎo)通繼電器吸合電機(jī)停止Lowresistancetriodeon-relaydrawsmotortostop紅外線傳感器infraredsensorPart

04車輛檢測技術(shù)Vehicledetectiontechnology四、紅外線傳感器

infraredsensor紅外線溫度傳感器是利用紅外線的物理性質(zhì)來進(jìn)行無接觸測溫的傳感器，它是一種將紅外輻射轉(zhuǎn)換成電量變化的裝置。Infraredtemperaturesensorisasensorthatusesthephysicalpropertiesofinfraredtomeasuretemperaturewithoutcontact,anditisadevicethatconvertsinfraredradiationintoelectricitychange.任何物質(zhì)的溫度只要高于絕對(duì)零度，都能輻射紅外線，物體的溫度越高，輻射功率就越大。Aslongasthetemperatureofanysubstanceisaboveabsolutezero,itcanradiateinfraredrays,andthehigh