A measure of the strength of a source of light. Luminous IntensityA measure of the strength of a source of light. Luminous Intensity is measured in candela (cd). If in a given direction a source of light emits monochromatic ra... More is
measured in candela (cdAn indication that station work is complete and power operated doors on trains may be safely closed. More). If in a given direction a source of light emits
monochromatic radiation of frequency 540 x 1012Hz and the radiant
intensitySee Luminous Intensity. More in that direction is 1/683 watt per steradian, then the Luminous
IntensitySee Luminous Intensity. More of the source is 1 candela. One candela is equivalent to one
lumen per steradian.