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