candela (cd)The base unit of luminous intensity in the SI system of units. One (cd) candela is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 540 × 1012 Hz and that has a radiant intensity in that direction of 1/683 watt per steradian. Related category UNITSAlso on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History |