Origin of illuminance
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Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
The luminous flux per unit area at any point on a surface exposed to incident light. It is measured in luxes. Also called illumination
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