equal energy spectrum
spectrum of radiation whose spectral distribution of a radiometric quantity as a function of wavelength is constant throughout the visible region
Note 1 to entry: The radiation of the equi-energy spectrum is sometimes regarded as an illuminant, in which case it is denoted by the symbol E.
Note 2 to entry: This entry was numbered 845-03-14 in IEC 60050-845:1987.
Note 3 to entry: This entry was numbered 17-393 and 17-390 in CIE S 017:2011.