# 17-21-071

He; H

density of incident radiant energy with respect to area at a point on a real or imaginary surface

where Qe is radiant energy and A is the area on which the radiant energy is incident

Note 1 to entry: The quantity "radiant exposure" defined here must not be confused with the quantity named "exposure" which is used in the field of X- and γ-rays, the unit of which is coulomb per kilogram (C·kg−1).

Note 2 to entry: The corresponding photometric quantity is "luminous exposure". The corresponding quantity for photons is "photon exposure".

Note 3 to entry: The radiant exposure is expressed in joule per square metre (J·m−2 = W·s·m−2).

Note 4 to entry: This entry was numbered 845-01-42 in IEC 60050-845:1987.

Note 5 to entry: This entry was numbered 17-1021 in CIE S 017:2011.

Publication date: 2020-12