Txoj Cai Ua Haujlwm thiab Kev Ntsuam Xyuas yuam kev ntawm Infrared Thermometer
Infrared ntsuas qhov system muaj pes tsawg leeg
Kev ntsuas kub infrared txais ib txoj kev tsom xam point-by-point, uas yog, thermal tawg ntawm ib cheeb tsam hauv cheeb tsam ntawm cov khoom yog tsom rau ntawm ib qho kev ntsuas, thiab cov hluav taws xob hluav taws xob tau hloov mus rau hauv qhov kub thiab txias los ntawm emissivity ntawm cov khoom paub. . Vim yog cov khoom sib txawv, kev ntsuas ntau thiab siv sijhawm, cov qauv tsim thiab sab hauv ntawm cov ntsuas kub infrared txawv, tab sis cov qauv yooj yim feem ntau zoo sib xws, feem ntau suav nrog optical system, photodetector, teeb liab amplifier thiab teeb liab ua, tso tawm cov infrared. Cov hluav taws xob hluav taws xob tawm los ntawm lub tshuab hluav taws xob ntawm nws cov qauv yooj yim nkag mus rau hauv qhov muag pom, thiab cov hluav taws xob infrared yog hloov mus rau hauv cov hluav taws xob hloov hluav taws xob los ntawm lub tshuab hluav taws xob, uas tau hloov mus rau hauv cov teeb liab hluav taws xob sib txuas los ntawm tus ntes. Lub teeb liab dhau los ntawm lub amplifier thiab teeb liab ua Circuit Court, thiab hloov mus rau qhov kub ntawm qhov ntsuas lub hom phiaj tom qab raug kho raws li algorithm hauv qhov ntsuas thiab lub hom phiaj emissivity.
Yuam kev tsom xam ntawm Infrared Temperature Measurement
Txij li thaum qhov ntsuas kub infrared tsis yog kev sib cuag, yuav muaj ntau yam yuam kev, thiab muaj ntau yam uas cuam tshuam rau qhov yuam kev. Ntxiv rau qhov tseem ceeb ntawm qhov ntsuas nws tus kheej, nws feem ntau tshwm sim hauv cov hauv qab no.
1. Radiation tus nqi
Emissivity yog lub cev muaj nuj nqis ntawm cov khoom muaj peev xwm hluav taws xob txheeb ze rau lub cev dub. Nws tsis yog tsuas yog cuam tshuam rau cov khoom siv cov khoom zoo, qhov roughness ntawm qhov tsis sib xws, thiab lwm yam, tab sis kuj muaj feem xyuam rau cov kev taw qhia ntawm qhov kev xeem. Yog hais tias cov khoom yog ib tug du nto, nws directionality yog rhiab heev. Lub emissivity ntawm cov khoom sib txawv yog txawv, thiab tus nqi hluav taws xob hluav taws xob tau txais los ntawm tus ntsuas kub infrared los ntawm ib qho khoom yog proportional rau nws emissivity.
(1) Kev teeb tsa emissivity
Raws li Kirchhoff's theorem [2]: hemispherical monochromatic emissivity (ε) ntawm cov khoom nto yog sib npaug rau nws hemispherical monochromatic absorptivity ( ), ε=. Nyob rau hauv thermal equilibrium tej yam kev mob, lub zog hluav taws xob ntawm ib yam khoom yog sib npaug zos rau nws absorbed hwj chim, uas yog, lub sum ntawm tus absorption tus nqi ( ), reflectivity (ρ), thiab transmittance ( ) yog 1, uas yog, ntxiv rau ρ ntxiv {{ 3} }, thiab daim duab 3 piav qhia txog txoj cai saum toj no. Rau opaque (los yog nrog ib tug tej thickness) khoom transmittance pom =0, tsuas yog hluav taws xob thiab reflection (ntxiv rau ρ=1), thaum lub emissivity ntawm cov khoom yog siab dua, lub reflectivity yog me me, lub cuam tshuam ntawm keeb kwm yav dhau. thiab kev xav Tus nqi me dua, qhov tseeb ntawm qhov kev xeem yuav ntau dua; ntawm qhov tsis sib xws, qhov siab dua qhov kub ntawm keeb kwm yav dhau los yog qhov siab dua qhov kev cuam tshuam, qhov cuam tshuam ntau dua ntawm qhov kev sim. Nws tuaj yeem pom los ntawm qhov no tias nyob rau hauv cov txheej txheem tshawb pom tiag tiag, peb yuav tsum tau them sai sai rau qhov emissivity sib haum rau cov khoom sib txawv thiab cov ntsuas kub, thiab teeb tsa cov emissivity kom raug raws li qhov ua tau kom txo qhov yuam kev ntawm qhov ntsuas kub.
(2) Kuaj kaum
Lub emissivity muaj feem xyuam rau kev ntsuas kev taw qhia. Qhov loj dua lub kaum ntse ntse, qhov kev xeem yuam kev ntau dua. Qhov no yooj yim saib tsis tau thaum siv infrared rau ntsuas kub. Feem ntau hais lus, qhov ntsuas lub kaum sab xis yog qhov zoo tshaj plaws nyob rau hauv 30 degree, feem ntau tsis siab tshaj 45 degree, yog tias nws yuav tsum tau kuaj ntawm qhov kub siab tshaj 45 degree, qhov emissivity tuaj yeem txo qis rau kev kho. Yog tias cov ntaub ntawv ntsuas kub ntawm ob yam khoom zoo tib yam yuav tsum tau txiav txim siab thiab tshuaj xyuas, ces lub kaum sab xis ntawm qhov ntsuas yuav tsum yog tib yam thaum lub sijhawm ntsuas, kom nws sib piv ntau dua.
