radiant efficiency, <of a source of radiation>
quotient of the radiant flux of the emitted radiation and the power consumed by the source
Note 1 to entry: It is necessary to specify whether the power dissipated by auxiliary equipment (such as ballasts), if any, is included in the power consumed by the source.
Note 2 to entry: The radiant efficiency has unit one.
Note 3 to entry: This entry was numbered 845-01-54 in IEC 60050-845:1987.
Note 4 to entry: This entry was numbered 17-1018 in CIE S 017:2011.