红外测温工作原理.ppt

Thischartillustratesblackbodycurvesatdifferenttemperatures.Itshowsthat:Curvesfordifferenttemperaturesnevercross.Wecancalibrateaninstrumenttomeasuretemperatureatanypointintheelectromagneticspectrum.Energyincreaseswithtemperature.Temperatureincreasesshiftcurvetoshorterwavelengths.Theslopeofthecurveisgreateratshorterwavelengths.Thereismoreenergydifferenceperdegreedifferenceontheshorterwavelengthsideofthepeak.Therefore,shorterwavelengthsprovideamoresensitivemeasureoftemperature.EnergyfromobjectpassesthroughenvironmentWatervaporandCO2mayabsorbenergy,givinglowerreadingsIRmeasurementbandsAtmosphericcorrectionbuiltintoproductsEnergyfromtheobjectistransmittedthroughtheatmospheretothesensor.Dust,steam,andparticleswhichareintheatmospherebetweentheobjectandthesennsorcanreducetheradiatedenergywhichreachesthesensor.Airpurgingkeepsthelensofthesensorclearandclean.Sensorshouldbeprotectedfromhighambienttempeatures.Usewateroraircoolingalongwithairpurgin.Usehgihtempeaturecablesandconduitifnecessary.Carefulselectionofmountinglocation.T-ambientfunctioncorrectforhightempertresinsurroundingareas.红外测温原理与选型上海皇龙自动化工程有限公司吕江明红外测温发展过程1800年赫胥尔发现红外线1828年M’Sweeny第一个辐射温度计19世纪末消隐光学高温计1901年全辐射测温仪专利(Fery)1931年商用全辐射测温仪问世(LeedsNorthrupcompany)60年代后迅猛发展近二十年双色、光纤、扫描等红外测温的原理

红外测温仪可捕捉从所有物体辐射出的红外能量。红外辐射是电磁频谱的一部分，电磁频谱中包括无线电波、微波、可见光、紫外线、伽玛射线和X光。可见光紫外光红外光X-射线GammaRays无线电波EHFSHFUHFVHFHFMFLFVLF0.1A1A1UA100A0.11101001cm0.1cm10cm1m100m1km10km100km波长10m30201510864321.510.80.60.4波长(um)常用红外光谱范围红外测温技术的基础

绝对零度(-273℃)以上的物体都辐射红外能量波长发射率距离系数红外测温的几个重要概念温度与辐射能量的关系

黑体辐射光谱曲线的特性12345678910111213141500°C1000°C542°C260°C20°C不同温度的辐射曲线永