Lux ' meter ' units thiab daim ntawv thov
Unit ntawm illuminance meter
Ntau tus neeg siv khoom yuav hais tias, 'Kuv xav yuav lub ntsuas hluav taws xob,' thiab ib txwm nug seb lub ntsuas hluav taws xob yog dab tsi! Tam sim no cia peb luv luv qhia illuminance. Illuminance yog ib chav tsev uas qhia txog qhov siv ntawm lub teeb, thiab nws lub ntsiab lus ntawm lub cev yog tus nqi ntawm lub teeb tawm hauv ib cheeb tsam. Illuminance yog ntsuas nyob rau hauv lumens ib square meter (Lm), los yog lux: 1Lux=1Lm/m2. Los ntawm qhov sib npaug saum toj no, nws tuaj yeem pom tau tias Lm yog chav tsev ntawm luminous flux, txhais tau tias yog lub teeb hluav taws xob los ntawm cov platinum ntshiab ntawm qhov kub ntawm qhov kub (kwv yees li 1770 degree) nrog thaj tsam ntawm 1/60 square meter hauv ib qho khoom. lub kaum sab xis ntawm 1 spherical degree.
Qhov kev piav qhia ntawm lub teeb pom kev zoo saum toj no zoo li theoretical thiab feem ntau nyuaj rau kev nkag siab. Txhawm rau kom muaj kev nkag siab ntau ntxiv ntawm qhov teeb pom kev zoo, piv txwv li, 100W incandescent teeb emits tag nrho cov luminous flux txog 1200Lm. Yog hais tias lub luminous flux yog uniformly faib rau ib tug ib nrab kheej kheej nto, lub illuminance qhov tseem ceeb ntawm 1m thiab 5m los ntawm lub teeb qhov chaw tuaj yeem tau raws li cov kauj ruam hauv qab no: thaj chaw hemispherical nrog lub vojvoog ntawm 1m yog 2 π × 12=6 .28 m2, thiab tus nqi illuminance ntawm 1m ntawm lub teeb qhov chaw yog 1200Lm / 6.28 m2=191Lux. Ib yam li ntawd, thaj chaw hemispherical nrog lub vojvoog ntawm 5m yog 2 π × 52=157 m2, thiab qhov ntsuas qhov pom ntawm qhov deb ntawm 5m ntawm lub teeb ci yog 1200Lm / 157 m2=7.64Lux.
Qhov xwm txheej dav dav: Kwv yees li 100000 LUX nyob rau lub caij ntuj sov hauv qab hnub ci; Lub teeb siv sab nraum zoov rau hnub huab cua yog 10000LUX; Lub teeb ci sab hauv tsev yog 100LUX; Lub teeb pom kev ntawm lub desktop 60cm deb ntawm 60W lub rooj teeb yog 300LUX; Lub teeb pom kev nyob hauv chav tshaj tawm hauv TV yog 1000LUX; Thaum tsaus ntuj, chav tsev muaj lub teeb ci ntawm 10LUX; Lub teeb pom kev hmo ntuj yog 0.1LUX; Lub teeb ci ntsa iab (ntawm qhov deb ntawm 20cm) yog 10-15 LUX.
