FLIR TG56 - Infrared Energy and IR Thermometer Theory

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FLIRTG54_TG56UserManual25DocumentIdentifier:TG54_TG56‐en‐US_AA
9.2InfraredEnergyandIRThermometerTheory
Infraredenergyispartofacompleterangeofradiationcalledtheelectromagneticspectrum.
Theelectromagneticspectrumincludesgammarays,X‐rays,ultraviolet,visible,infrared,
microwaves(RADAR),andradiowaves.Theonlydifferenceistheirwavelengthorfrequency.All
oftheseformsofradiationtravelatthespeedoflight.Infraredradiationliesbetweenthe
visibleandRADARportionsoftheelectromagneticspectrum.
Theprimarysourceofinfraredradiationisheatorthermalradiation.Anyobjectwhichhasa 
temperatureradiatesintheinfraredportionoftheelectromagneticspectrum.Evenobjects
thatareverycold,suchasanicecube,emit
infrared.Whenanobjectisnotquitehotenoughto
radiatevisiblelight,itwillemitmostofitsenergyintheinfrared.Forexample,hotcharcoal
maynotgiveofflight,butitdoesemitinfraredradiation,whichwefeelasheat.Thewarmer
theobject,themoreinfraredradiationitemits.
IRThermometersmeasureanobject’ssurfacetemperature.Thethermometer’sopticssensean
object’semitted,reflected,andtransmittedenergy.
TheTGSeriestranslatesthesensedinformation(targetedbytheLaser)intoatemperature
readingthatisdisplayedintextonthecenterofthedisplay.Ifthethermometermeasurement
exceedsthepublishedtemperaturerange,thedisplaywillindicateOL.
TheamountofIRenergyemittedbyanobjectisproportionaltoanobject'stemperatureandits
abilitytoemitenergy.Thisabilityisknownasemissivityandisbasedonthematerialofthe
objectanditssurfacefinish.Emissivity
valuesrangefrom0.1foraveryreflectiveobjectto1.00
foraflatblackfinish.
TheTGSerieshasbothadjustableandpresetemissivitysettings.Therearefour(4)presetsand
anadjustableemissivityspanfrom0.10to0.99.SeetheAppendixforalistofcommon
materialsand
theirrespectiveEmissivityfactors.AccesstheProgrammingmenu(coveredin
Section6)tosetthedesiredemissivityfactor.