精密温度与电阻电路

Themostwidelymeasuredphenomenaintheprocess

controlenvironmentistemperature.Common

elements,suchasResistanceTemperatureDetectors

(RTDs),thermistors[7],thermocouples[6]ordiodes

areusedtosenseabsolutetemperatures,aswellas

changesintemperature.Foranoverviewandcompar-

isonofthesesensors,refertoMicrochip’sAN679,

“Temperature-SensingTechnologies”[5].

Ofthesetechnologies,theplatinumRTDtemperature-

sensingelementisthemostaccurate,linearandstable

overtime[1]andtemperature.RTDelementtechnolo-

giesareconstantlyimproving,furtherenhancingthe

qualityofthetemperaturemeasurement.Typically,a

dataacquisitionsystemconditionstheanalogsignal

fromtheRTDsensor,makingtheanalogtranslationof

thetemperatureusableinthedigitaldomain.AN687PrecisionTemperature-SensingWithRTDCircuitsAuthor:BonnieC.BakerRTDOVERVIEWMicrochipTechnologyInc.Theacronym“RTD”isderivedfromtheterm“Resis-tanceTemperatureDetector”[4].Themoststable,INTRODUCTIONlinearandrepeatableRTDismadeofplatinummetal.ThetemperaturecoefficientoftheRTDelementisThemostwidelymeasuredphenomenaintheprocesspositiveandalmostconstant.controlenvironmentistempe