Luminous Efficacy (of a source)
The quotient of the luminous flux emitted by the power consumed.
Unit: lumen per watt (Im/W)
Note: Formerly Luminous Efficiency
Reference: C.I.E. (modified)
Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)
Celsius (previously Centigrade)
International Association of Marine Aids to Navigation and Lighthouse Authorities - AISM