cie

17-21-063

cylindrical illuminance

Ev,c; Ec

mean value of illuminance on the outer curved surface of a very small (real or imaginary) cylinder that is oriented vertically at a point in space

Note 1 to entry: Cylindrical illuminance is sometimes also defined as the arithmetic mean of the vertical illuminance, Ev,v, at a point

where Ev,v is the vertical illuminance for an area element with its normal in the direction φ, and φ is the angle in the plane perpendicular to the axis of the cylinder.

Note 2 to entry: The corresponding radiometric quantity is "cylindrical irradiance". The corresponding quantity for photons is "photon cylindrical irradiance".

Note 3 to entry: The cylindrical illuminance is expressed in lux (lx = lm·m−2).

Note 4 to entry: This entry was numbered 17-273 in CIE S 017:2011.

Publication date: 2020-12
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