電子信息類專業(yè)英語Unit-15-Temperature-Sensors-課件

Unit15TemperatureSensorsTextKeywordsTechnicaltermsExpressionsNotestothetextUnit15TemperatureSensorsTText

Oneoftheprimarymethodsforelectricalmeasurementoftemperatureinvolveschangesintheelectricalresistanceofcertainmaterials.Inthis,aswellasothercases,theprinciplemeasurementtechniqueistoplacethetemperature-sensingdeviceincontactwiththeenvironmentwhosetemperatureistobemeasured.Thesensingdevicethentakesonthetemperatureoftheenvironment.Thusameasureofitsresistanceindicatesthetemperatureofthedeviceandtheenvironmentmustwaituntilthedevicecomesintothermalequilibriumwiththeenvironment.ThetwobasicdevicesusedastheResistance-TemperatureDetector(RTD),Text

Oneoftheprimarymethbasedonthevariationofmetalresistancewithtemperature,andthethermistor,basedonthevariationofsemiconductorresistancewithtemperature.

Thereexistsanotherdependenceofelectricalbehaviorofmaterialsontemperaturethatformsthebasisofalargepercentageofalltemperaturemeasurement.Thiseffectischaracterizedbyavoltage-generatingsensorinwhichanelectromotiveforce(emf)isproducedthatisproportionaltotemperature.Suchanemfisfoundtobealmostlinearwithtemperatureandveryrepeatableforconstantmaterials.Devicesthatmeasuretemperatureonthebasisofthisthermoelectricprinciplearecalledthermocouples(TCs).basedonthevariationofmetaHerewe’llbrieflydiscussthecharacteristicsofResistance-TemperatureDetector(RTD).

AResistance-TemperatureDetector(RTD)isatemperaturesensorthatisbasedontheprinciplesthatmetalresistanceincreasingwithtemperature.Metalusedinthesedevicesvaryfromplatinum,whichisveryrepeatable,quitesensitive,andveryexpensive,tonickel,whichisnotquitsasrepeatable,moresensitive,andlessexpensive.Herewe’llbrieflydiscusstSensitivityAnestimateofRTDsensitivitycanbenotedfromtypicalvaluesofa0,thelinearfractionalchangeinresistancewithtemperature.Forplatinum,thisnumberistypicallyontheorderof0.004/℃,andfornickelatypicalvalueis0.005/℃.Thus,withplatinum,forexample,achangeofonly0.4Ωwouldbeexpectedfora100ΩRTDifthetemperatureischangedby1℃.Usually,aspecificationwillprovidecalibrationinformationeitherasagraphofresistanceversustemperatureorasatableofvaluesfromwhichthesensitivitycanbedetermined.Forthesamematerials,however,thisnumberisrelativelyconstantbecauseitisafunctionofresistivity.SensitivityAnestimateofResponseTimeIngeneral,RTDhasaresponsetimeof0.5to5sormore.Theslownessofresponseisdueprincipallytotheslownessofthermalconductivityinbringingthedeviceintothermalequilibriumwithitsenvironment.

ConstructionARTD,ofcourse,issimplyalengthofwirewhoseresistanceistobemonitoredasafunctionoftemperature.Theconstructionistypicallysuchthatthewireiswoundonaform(inacoil)toachievesmallsizeandimprovethermalconductivitytodecreaseresponsetime.Inmanycases,thecoilisprotectivetubethatinevitablyincreasesresponsetimebutmaybenecessaryinhostileenvironments.Alooselyappliedstandardsetstheresistanceatmultiplesof100Ωforatemperatureof0℃.ResponseTimeIngeneral,RRangeTheeffectiverangeofRTDsdependsprincipallyonthetypeofwireusedastheactiveelement.Thus,atypicalplatinumRTDmayhavearangeof－100℃to650℃,whereasaRTDconstructedfromnickelmighttypicallyhaveaspecifiedrangeof－180℃to300℃.RangeTheeffectiverangeoKeywords

sensor n.傳感器

thermal adj.熱的，熱量的

equilibrium n.平衡，平靜，均衡

detector n.探測器，檢波器，檢電器

thermistor n.熱敏電阻

thermoelectric adj.熱電的

electromotive adj.電動的

thermocouple n.?[物]熱電偶

platinum n.白金，鉑

nickel n.?[化]鎳Keywords

sensor n.傳感器

repeatable adj.可重復(fù)的

sensitivity n.敏感，靈敏(度)，靈敏性

fractional adj.部分的

calibration n.標(biāo)度，刻度，校準(zhǔn)

graph n.圖表，曲線圖

versus prep.與…相對

resistivity n.抵抗力，電阻系數(shù)

conductivity n.傳導(dǎo)性，傳導(dǎo)率

inevitably adv.不可避免

hostile adj.敵對的，敵方的repeatable adj.可重復(fù)的

senTechnicalterms

temperature-sensingdevice 溫度敏感器件

thermalequilibrium 熱量平衡

Resistance-TemperatureDetector(RTD) 電阻溫度計(jì)

voltage-generatingsensor 產(chǎn)生電壓的傳感器

electromotiveforce(emf) 電動勢

theactiveelement 有源元件Technicalterms

temperature-Expressions

incontactwith… 與…相關(guān)，聯(lián)系

comeinto 達(dá)到，得到

basedon 基于

alargepercentageof 很大的百分比

belinearwith… 與…成線性

onthebasisof… 以…為基礎(chǔ)Expressions

incontactwith…Notestothetext

1.Inthis,aswellasothercases,theprinciplemeasurementtechniqueistoplacethetemperature-sensingdeviceincontactwiththeenvironmentwhosetemperatureistobemeasured.

無論何種測量，其測量技術(shù)的原理都是將溫度傳感裝置與被測溫的環(huán)境相接觸。句中，“toplacethetemperature-sensingdevice…”至句末的不定式用作表語；“whosetemperatureistobemeasured”為定語從句，修飾“environment”；“tobemeasured”是從句中的不定式作表語成分。Notestothetext

1.Inthis2.ThetwobasicdevicesusedastheResistance-TemperatureDetector(RTD),basedonthevariationofmetalresistancewithtemperature,andthethermistor,basedonthevariationofsemiconductorresistancewithtemperature.

使用的兩個測溫器件分別是電阻溫度計(jì)和熱敏電阻，其中前者是金屬電阻隨溫度變化而變化，后者是半導(dǎo)體電阻隨溫度變化而變化。句中的“basedonthevariationofmetalresistancewithtemperature”修飾“theResistance-TemperatureDetector(RTD)”；“basedonthevariationofsemiconductorresistancewithtemperature”修飾“thethermistor”；“theResistance-TemperatureDetector”和“thethermistor”相并列。2.Thetwobasicdevicesuse3.?Metalusedinthesedevicesvaryfromplatinum,whichisveryrepeatable,quitesensitive,andveryexpensive,tonickel,whichisnotquitsasrepeatable,moresensitive,andlessexpensive.

測溫裝置使用不同的金屬制成，可以是重復(fù)性好、靈敏度高、價格高的鉑，也可以是重復(fù)性不太好，但靈敏度更高、價格較低的鎳。句中的?“whichisveryrepeatable,quitesensitive,andveryexpensive”修飾“platinum”；“whichisnotquitsasrepeatable,moresensitive,andlessexpensive”修飾“nickel”。3.?MetalusedinthesedeviUnit15TemperatureSensorsTextKeywordsTechnicaltermsExpressionsNotestothetextUnit15TemperatureSensorsTText

Oneoftheprimarymethodsforelectricalmeasurementoftemperatureinvolveschangesintheelectricalresistanceofcertainmaterials.Inthis,aswellasothercases,theprinciplemeasurementtechniqueistoplacethetemperature-sensingdeviceincontactwiththeenvironmentwhosetemperatureistobemeasured.Thesensingdevicethentakesonthetemperatureoftheenvironment.Thusameasureofitsresistanceindicatesthetemperatureofthedeviceandtheenvironmentmustwaituntilthedevicecomesintothermalequilibriumwiththeenvironment.ThetwobasicdevicesusedastheResistance-TemperatureDetector(RTD),Text

Oneoftheprimarymethbasedonthevariationofmetalresistancewithtemperature,andthethermistor,basedonthevariationofsemiconductorresistancewithtemperature.

Thereexistsanotherdependenceofelectricalbehaviorofmaterialsontemperaturethatformsthebasisofalargepercentageofalltemperaturemeasurement.Thiseffectischaracterizedbyavoltage-generatingsensorinwhichanelectromotiveforce(emf)isproducedthatisproportionaltotemperature.Suchanemfisfoundtobealmostlinearwithtemperatureandveryrepeatableforconstantmaterials.Devicesthatmeasuretemperatureonthebasisofthisthermoelectricprinciplearecalledthermocouples(TCs).basedonthevariationofmetaHerewe’llbrieflydiscussthecharacteristicsofResistance-TemperatureDetector(RTD).

AResistance-TemperatureDetector(RTD)isatemperaturesensorthatisbasedontheprinciplesthatmetalresistanceincreasingwithtemperature.Metalusedinthesedevicesvaryfromplatinum,whichisveryrepeatable,quitesensitive,andveryexpensive,tonickel,whichisnotquitsasrepeatable,moresensitive,andlessexpensive.Herewe’llbrieflydiscusstSensitivityAnestimateofRTDsensitivitycanbenotedfromtypicalvaluesofa0,thelinearfractionalchangeinresistancewithtemperature.Forplatinum,thisnumberistypicallyontheorderof0.004/℃,andfornickelatypicalvalueis0.005/℃.Thus,withplatinum,forexample,achangeofonly0.4Ωwouldbeexpectedfora100ΩRTDifthetemperatureischangedby1℃.Usually,aspecificationwillprovidecalibrationinformationeitherasagraphofresistanceversustemperatureorasatableofvaluesfromwhichthesensitivitycanbedetermined.Forthesamematerials,however,thisnumberisrelativelyconstantbecauseitisafunctionofresistivity.SensitivityAnestimateofResponseTimeIngeneral,RTDhasaresponsetimeof0.5to5sormore.Theslownessofresponseisdueprincipallytotheslownessofthermalconductivityinbringingthedeviceintothermalequilibriumwithitsenvironment.

ConstructionARTD,ofcourse,issimplyalengthofwirewhoseresistanceistobemonitoredasafunctionoftemperature.Theconstructionistypicallysuchthatthewireiswoundonaform(inacoil)toachievesmallsizeandimprovethermalconductivitytodecreaseresponsetime.Inmanycases,thecoilisprotectivetubethatinevitablyincreasesresponsetimebutmaybenecessaryinhostileenvironments.Alooselyappliedstandardsetstheresistanceatmultiplesof100Ωforatemperatureof0℃.ResponseTimeIngeneral,RRangeTheeffectiverangeofRTDsdependsprincipallyonthetypeofwireusedastheactiveelement.Thus,atypicalplatinumRTDmayhavearangeof－100℃to650℃,whereasaRTDconstructedfromnickelmighttypicallyhaveaspecifiedrangeof－180℃to300℃.RangeTheeffectiverangeoKeywords

sensor n.傳感器

thermal adj.熱的，熱量的

equilibrium n.平衡，平靜，均衡

detector n.探測器，檢波器，檢電器

thermistor n.熱敏電阻

thermoelectric adj.熱電的

electromotive adj.電動的

thermocouple n.?[物]熱電偶

platinum n.白金，鉑

nickel n.?[化]鎳Keywords

sensor n.傳感器

repeatable adj.可重復(fù)的

sensitivity n.敏感，靈敏(度)，靈敏性

fractional adj.部分的

calibration n.標(biāo)度，刻度，校準(zhǔn)

graph n.圖表，曲線圖

versus prep.與…相對

resistivity n.抵抗力，電阻系數(shù)

conductivity n.傳導(dǎo)性，傳導(dǎo)率

inevitably adv.不可避免

hostile adj.敵對的，敵方的repeatable adj.可重復(fù)的

senTechnicalterms

temperature-sensingdevice 溫度敏感器件

thermalequilibrium 熱量平衡

Resistance-TemperatureDetector(RTD) 電阻溫度計(jì)

voltage-generatingsensor 產(chǎn)生電壓的傳感器

electromotiveforce(emf) 電動勢

theactiveelement 有源元件Technicalterms

temperature-Expressions

incontactwith… 與…相關(guān)，聯(lián)系

comeinto 達(dá)到，得到

basedon 基于

alargepercentageof 很大的百分比

belinearwith… 與…成線性

onthebasisof… 以…為基礎(chǔ)Expressions

incontactwith…Notestothetext

1.Inthis,aswellasothercases,theprinciplemeasurementtechniqueistoplacethetemperature-sensingdeviceincontactwiththeenvironmentwhosetemperatureistobemeasured