Correlation ntawm illuminance ntsuas los ntawm illuminance meter thiab illuminance unit
(1) Thaum lub teeb ci ci rau ntawm ib qho khoom, peb tuaj yeem ntsuas qhov twg yog qhov tawm los ntawm lub teeb ci (Lumvnance? D brightness) lossis qhov twg yog qhov cuam tshuam los ntawm cov khoom (Illuminance? D illumination).
(2) Illumination nyob ntawm qhov kev xav ntawm qhov khoom. Nws zoo ib yam li daim duab nyob rau hauv uas nws ntsuas tsuas yog reflected lub teeb. Nws chav tsev yog lux.
(3) Txawm li cas los xij, lub teeb EL yog lub teeb ci: nws yuav tsum tau qhia hauv qhov ci ci, uas yog fL (ko taw-lambert) lossis cd / m2, tseem hu ua "nits". Qee tus engineers nyiam siv fL, thaum lub koom haum thoob ntiaj teb cov qauv siv cov nits. Cov qauv rau kev hloov cov nits thiab fL yog: 1nits × 0 2919=1fL; thiab 1fL×3.426=1nits [Note; Cov yam ntxwv no tau muab los ntawm pi (π) thiab m2/ft2 ({11}}.0929).
(4) Pom tseeb, siv lux yog chav tsev tsis raug, thiab nws tsis tuaj yeem hloov los ntawm lux mus rau lwm chav. 1 Lux=1 lumenpersquaremeter= 0.0929 footcandle 1 footcandle= 1lumen persquarefoot =10.764 Lux1 ko taw Lambert= 3.426 candelas per squaremeter (nit) 1nit ( candelas ib square meter)=0.2919 ko taw Lambert
Luminous flux
Luminous flux: Tus nqi ntawm lub teeb lub zog tawm los ntawm lub teeb qhov chaw lossis qhov ntws ntawm lub teeb (Flowarte). Nws yog qhov yooj yim kom muaj nuj nqis uas piav qhia txog lub peev xwm ntawm lub teeb ci kom emit lub teeb. Chav tsev yog Lumen. Piv txwv li, ib lub teeb hluav taws xob 100-watt (W) tuaj yeem tsim tau 1,750lm, thaum lub 40W txias dawb fluorescent raj tuaj yeem tsim 3,150lm ntawm luminous flux. Raws li lub ntsiab txhais, 1lm yog lub luminous flux emitted los ntawm ib tug uniform point lub teeb qhov chaw nrog luminous siv (l) 1cd nyob rau hauv ib tug khoom lub kaum sab xis ntawm 1 steradian.
lub teeb siv
Luminous intensity (Luminousintensity, Candlepower): Luminous siv, hu ua luminosity, yog hais txog lub luminous flux tawm los ntawm lub kaum sab xis (unit: sr) ntawm lub teeb qhov chaw, uas yog, qhov ntom ntom ntawm cov luminous flux emitted los ntawm lub teeb. qhov chaw los yog teeb pom kev zoo fixture nyob rau hauv ib tug xaiv kev taw qhia nyob rau hauv qhov chaw. Chav tsev yog tswm ciab (CandleorCandela, cd). Lub teeb qhov chaw nrog luminous siv ntawm 1cd tuaj yeem tso tawm lub teeb ci ntawm 12.57lm. Illuminance: Qhov ntom ntawm lub teeb flux tau txais ntawm lub dav hlau illuminated, uas tuaj yeem ntsuas los ntawm lub teeb flux ntawm ib cheeb tsam. Lub luminous flux ntawm 1lm yog sib npaug ntawm qhov chaw ntawm 1 square meter (m2), uas ua rau lub teeb pom kev ntawm 1 lux (Lux, ib puag ncig technology> illuminance meter); lub luminous flux ntawm 1lm ntog rau ntawm qhov chaw ntawm 1 square feet (ft2), thiab nws tus nqi illumination yog 1 footcandle (Footcandle, fc).
