Luminous coefficient

Luminous coefficient

The luminous coefficient is a coefficient that measures the integrated fraction of the radiant power that contributes to its luminous properties as evaluated by means of the standard luminosity function. [cite book|title=Van Nostrand's Scientific Encyclopedia, 3rd Edition| publisher=D. Van Nostrand Company, Inc.| location=Princeton, New Jersey, Toronto, London, New York| month=January | year=1958] The luminosity coefficient is

:frac{ int^{lambda = infin}_{lambda = 0} y_lambda J_lambda dlambda } { int^{lambda = infin}_{lambda = 0} J_lambda dlambda },

where

"y"λ is the standard luminosity function,

"J"λ is the spectral power distribution of the radiant intensity.

The luminous coefficient is unity for a narrow band of wavelengths at 555 nanometres.

ee also

*Luminous efficiency, the more common name for luminous coefficient
*Photometry

References


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