Ifyou'veentered a bank, postoffice, orairportinthepastyear, you'veprobablyhadyourtemperaturetaken. Itprobablywasn't withthetraditionalglass, liquid-filledthermometermanyolderfolksarefamiliarwith.
Onesuchdeviceisknownasaninfraredthermometer. Itmaybeheldcloseto, butwon't touch, a person's forehead. Theinfraredthermometerprovides a digitalreadoutoftheperson's temperature. Itcontains a lensthatfocusesheatenergyonto a detectorcalled a thermopile.
Thisheatisturnedintoelectricity, whichisthentransmittedtoanotherdetectorformeasurement. Themoreelectricityemittedby a target, thehotterthepersonorobjectis. Basically, infraredthermometersareheatdetectors, recording a person's “heatsignature.”
Aninfraredsensormayalsobeused. Thisis a muchlargerdevicethatcanmeasuretemperaturefrom a distanceofseveralmeters. A person's imagecanbeseenon a screenthatissimilarto a televisionset. Thisinfraredmachinenotonlymeasures a person's temperaturebutalsodisplaysit.
Thehighesttemperaturesdetectedappearasbrightred, whilelowertemperaturesusuallyshowupasorangeoryellow. Thesemachinescanhandleseveralpeopleat a time, whichisidealforlargebuildingsandmajortransportationhubs, likeairportsandsubwaystations.
Boththeinfraredthermometerandtheinfraredsensorarenon-invasive, detectingandmeasuringinfraredlightfrequency—thetemperatureofanyobjecttheyfocuson. Thesedevicesarehelpingmedicalprofessionalsidentifyandthentreatpeopleshowingsignsof a fever.