<noinclude> <noinclude> luminous energy : visible radiant energy, visible light ; units are lumen*seconds or Talbots (T = lm*s) ; lumen = candela*steradian ... Jump to: navigation, search The second (symbol: s) is the SI base unit of time. ... In photometry the Talbot (T) is a nonstandard unit of luminous energy. ... Luminous flux is a measure of the energy emitted by a light source in all directions. ... Jump to: navigation, search The lumen (symbol: lm) is the SI unit of luminous flux. ... The steradian (ste from Greek stereos, solid) is the SI derived unit of solid angle, and the 3-dimensional equivalent of the radian. ... Luminous intensity is a measure of the energy emitted by a light source in a particular direction. ... The candela (symbol: cd, Latin for candle) is one of the seven SI base units. ... The word luminance, a synonym for luminosity, means emitting or reflecting light. ... A square metre (US spelling: square meter) is by definition the area enclosed by a square with sides each 1 metre long. ... Illuminance is the total luminous flux incident per unit area. ... The lux (symbol: lx) is the SI derived unit of illuminance or illumination. ... Luminous efficacy is a measure of the proportion of the energy supplied to a lamp that is converted into light energy. ... The watt (symbol: W) is the SI derived unit of power. ...
The unit is designed to equal 1/60 degree [2], although actual degrees of latitude vary from about 59.7 to 60.3 nautical miles.
The neper is accepted for use with SI units, and it may become an SI unit in the future.
The nit is not approved as part of the SI, but it has been approved since 1947 by the International Commission on Illumination (CIE) and is in wide use.
Feeds |
Contact