total flux, <of a light source>
cumulative flux for the solid angle 4π sr
Note 1 to entry: The total flux is expressed in lumen (lm).
Note 2 to entry: This entry was numbered 845-09-33 in IEC 60050-845:1987.
Note 3 to entry: This entry was numbered 17-1323 in CIE S 017:2011.