CANDELA

SI unit of measurement, defined as the luminous intensity in a given direction of a source that emits monochromatic radiation of frequency 540 1012 hertz and has a radiant intensity in that same direction of 1/683 watt per steradian (unit solid angle). The candela, abbreviated as cd, has replaced the standard candle or lamp as a unit of luminous intensity in calculations involving artificial lighting and is sometimes called the new candle.