| 摘要 |
PURPOSE:To enable the measurement of the ratio of spectral separation free from measurement restrictions such as the particularity of a light source, by obtaining a solution according to Planck's formula of radiation under prescribed boundary conditions on the basis of detection data on separated radiation fluxes of (m) colors from a measured object. CONSTITUTION:Light flux from a measured light source 2 made of a film 2b, whose spectral radiation separation ratio is unknown and which covers a perfect black body 2a of unknown temperature, is spectrally separated into light fluxes of three colors or the like by a filter 4. After the light fluxes are detected by a photoelectric converter 5a, the fluxes undergo A/D conversion. Compensation is effected by a calculator 6 depending on the transmission factor, gain, etc. of the filter. A compensated value is stored. The indexes of dispersion epsilon1-epsilon3 corresponding to effective wavelengths lambda1-lambda3 and a temperature T are computed by the calculator 6 from m-color (three colors or the like) detected values Xi based on the stored value, dispersive power (epsiloni) calculation formulae I, II based on Planck's formula of radiation and boundary conditions which restrict to (m-1) the degree of freedom calculated according to another formula III. The ratio of spectral radiation separation of the film 2b is thereby determined independently of measurement particularity. In this case, a condition n>=m>=3 is necessitated. |
