cylindrical illuminance
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,
where
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.