cumulative flux, <of a light source, for a solid angle>
luminous flux emitted by the light source under operating conditions, within a cone having a vertically downward axis and enclosing the solid angle
Note 1 to entry: The cumulative flux is expressed in lumen (lm).
Note 2 to entry: In radiometry the term "cumulative flux" is also used with respect to radiant flux instead of luminous flux and in that case is expressed in watt (W).
Note 3 to entry: This entry was numbered 845-09-31 in IEC 60050-845:1987.
Note 4 to entry: This entry was numbered 17-267 in CIE S 017:2011.