Spectral Luminous Efficacy definition of Spectral Luminous Efficacy in the Free Online Encyclopedia.

spectral luminous efficacy [′spek·trəl ′lü·mə·nəs ′ef·i·kə·sē]

(optics)

The ratio of the luminous flux emitted by a monochromatic light source in lumens to its radiant flux in watts, as a function of the wavelength of the emitted light.

Spectral Luminous Efficacy

For radiation in the range of wavelengths λ or frequencies v perceived by the human eye, that is, in the visible range, the spectral luminous efficacy of radiant power is the ratio of the luminous flux at a given wavelength of light (monochromatic light) to the corresponding radiant power, or radiant flux. Spectral luminous efficacy is denoted by K(\) and assumes its maximum value K_m ≃ 680 lumens/watt at λ = 555 nanometers.

A related quantity of some importance is the spectral luminous efficiency V(λ) = K(λ)/K_m. It has also been called the relative spectral luminous efficacy and the relative luminosity (the term “luminosity” was formerly applied to the spectral luminous effi cacy). The system of photometric quantities is based on the two quantities K(λ) and V(λ). (See alsoLUMINOUS EFFICACY OF RADIANT POWER and .)

Mentioned in	?		Encyclopedia browser	?		Full browser	?
No references found			spectral approximation Spectral Band Replication spectral bands spectral bandwidth spectral centroid spectral characteristic spectral class spectral classification Spectral Classification of Stars spectral color Spectral Concentration spectral density spectral dimension spectral directional reflectance factor spectral emissivity spectral energy distribution spectral extinction spectral factorization spectral function spectral hygrometer spectral irradiance Spectral Line Spectral Lines, Width of spectral locus spectral luminosity classification Spectral Luminous Efficacy spectral luminous efficiency spectral measure spectral photography spectral power distribution spectral pyrometer spectral radiance spectral radiance factor spectral radius spectral reflectance spectral regions Spectral Resolution of a Function Spectral Resolution of a Linear Operator Spectral Resolution of a Random Function spectral response spectral selective photoelectric effect Spectral Sensitivity Spectral Series spectral temperature Spectral Term spectral theorems spectral transmission spectral type spectral width spectral-shift reactor spectre			spectral hygrometer Spectral Imagery Technology Applications Center SPectral Imaging of Correlative Events Spectral Information Divergence Spectral Information Measure Spectral Information Technology Applications Center Spectral Infrared Interferometric Telescope Spectral Infrared Remote Imaging Transition Testbed Spectral irradiance Spectral irradiance Spectral Irradiance Model Spectral karyotyping Spectral karyotyping Spectral karyotyping Spectral karyotyping Spectral Lanczos Decomposition Method Spectral Latent Heating Spectral lemur spectral line spectral line Spectral line broadening Spectral line broadening Spectral line width Spectral line width Spectral lines Spectral lines Spectral Lines, Width of Spectral linewidth spectral locus spectral luminosity classification Spectral Luminous Efficacy spectral luminous efficiency spectral luminous efficiency spectral luminous efficiency Spectral measure Spectral Mesosphere Lower Thermosphere Model Spectral Methods and Multirate Signal Processing Spectral Ocean Wave Model Spectral Operations Resource Center Spectral Optical Coherence Tomography Spectral Phase Interferometry for Direct Electric-Field Reconstruction spectral photography Spectral power density Spectral power distribution Spectral power distribution Spectral power distributions Spectral Presaturation by Inversion Recovery Spectral Processing and Manipulation Spectral Properties of Fluorescein in Solvent spectral pyrometer Spectral radiance Spectral radiance Spectral radiance spectral radiance factor Spectral radius Spectral Recording Spectral reflecance Spectral reflecance Spectral reflecance Spectral reflectance Spectral reflectance