Theoretical Principple thiab Application of Infrared Thermometers
Nyob rau hauv qhov xwm txheej, thaum ib qho khoom kub siab tshaj qhov xoom, nws tsis tu ncua emits electromagnetic nthwv dej mus rau ib puag ncig vim yog thermal zog. Cov nthwv dej no suav nrog cov hluav taws xob infrared nyob rau hauv lub wavelength ntawm 0.75 µm txog 100 µm. Ib tug yam ntxwv yam ntxwv yog hais tias, ntawm ib tug muab kub thiab wavelength, lub radiant zog emitted los ntawm ib yam khoom mus txog qhov siab tshaj plaws. Cov khoom zoo li no hu ua blackbody, nrog rau emissivity teem rau 1. Tag nrho lwm yam khoom, nrog emissivity tsawg dua 1, raug xa mus rau greybodies.
Lub spectral radiant zog P(λ,T) ntawm ib tug blackbody ua raws Planck txoj cai raws li ib tug muaj nuj nqi ntawm qhov kub thiab txias T. Txoj cai no piav qhia txog lub zog radiant nyob rau ib cheeb tsam ntawm ib tug blackbody ntawm wavelength λ thiab qhov kub thiab txias T.
Thaum kub nce, lub zog radiant ntawm ib yam khoom yuav muaj zog. Qhov no yog lub hauv paus ntawm infrared radiation txoj kev xav thiab lub hauv paus tsim rau ib leeg-band infrared ntsuas kub.
Raws li qhov kub thiab txias, qhov hluav taws xob peak hloov mus rau luv wavelengths (sab laug), ua raws Wien Txoj Cai Hloov Pauv: lub ncov wavelength yog inversely proportional rau qhov kub thiab txias T. Cov kab dashed sawv cev rau qhov chaw ntawm cov txiaj ntsig ncov. Qhov kev sib raug zoo no piav qhia tias yog vim li cas cov ntsuas kub kub feem ntau ua haujlwm ntawm qhov luv wavelengths, thaum cov ntsuas kub qis siv cov wavelengths ntev.
Tus nqi ntawm kev hloov pauv ntawm lub zog radiant nrog rau qhov kub thiab txias yog ntau dua ntawm luv wavelengths tshaj qhov ntev dua. Hauv lwm lo lus, cov ntsuas ntsuas kub ua haujlwm ntawm qhov luv luv wavelength muaj lub teeb liab-rau-nruab sib piv (sensitivity siab dua) thiab muaj zog tiv thaiv kev cuam tshuam. Thermometers yuav tsum tau tsim los ua haujlwm nyob ze ntawm lub ncov wavelength, tshwj xeeb tshaj yog rau qhov kub thiab txias me me, qhov no yog qhov tseem ceeb tshwj xeeb.
Ntu Ob
Lub ntsuas kub infrared muaj lub kaw lus kho qhov muag, lub ntsuas hluav taws xob photoelectric, lub teeb liab amplifier, lub teeb liab ua cov khoom siv hluav taws xob, thiab cov khoom tso tawm module.Radiation los ntawm cov khoom ntsuas thiab cov ntaub ntawv siv yog hloov los ntawm modulator thiab tom qab ntawd nkag mus rau lub ntsuas hluav taws xob infrared.Qhov sib txawv ntawm ob lub teeb liab yog amplified los ntawm ib qho inverse amplifier thiab siv los ntsuas qhov ntsuas kub ntawm qhov ntsuas kub ntawm qhov ntsuas kub. object.Cov zaub ces qhia qhov ci ntsa iab kub ntawm cov khoom ntsuas.
