illuminance

[ ih-loo-muh-nuhns ]

noun

, Optics.

1. illumination ( def 6 ).

illuminance

/ ɪˈluːmɪnəns /

noun

1. the luminous flux incident on unit area of a surface. It is measured in lux Ev Sometimes calledillumination Compare irradiance

illuminance

/ ĭ-lo̅o̅′mə-nəns /

1. The luminous flux per unit area at any point on a surface exposed to incident light. It is measured in luxes.
2. Also called illumination

Word History and Origins

Origin of illuminance¹

First recorded in 1940–45; illumin(ate) + -ance