Abstract
A fluorescent sample absorbs spectral radiations and emits its fluorescence radiation due to the excitation of fluorescent material by that absorbed. The fluorescence radiation is found in a spectral range louger than that of its absorption. This excitation and the emission of a fluorescent sample are usually found simultaneously in a rather wide spectral range. The existence of this overlapping region of a fluorescent sample makes it difficult to measure its reflective radiance factor in a two-monochro-mator method. This problem is solved by the following method.
(1) At a specified wavelength in the overlapping region, a total spectral radiance factor of a fluorescent sample is composed of a reflective and a fluorescent spectral radiance factor. The fluorescent spectral radiance factor at the wavelength is interpolated on the basis of a few measurements of spectral radiance of the fluorescent sample by changing the wavelength setting of an analyzing second monochromator. The reflective spectral radiance factor is estimated by subtructing the interpolated fluorescent spectral radiance factor from the corresponding total spectral radiance factor.
(2) The reflective spectral radiance factor in the overlapping region was measured for two kinds of fluorescent samples with an orange and a green color. The repeatability of measurements was estimaed to be better than ±0.4%. The effectiveness and the simplicity of the proposed method was confirmed based on the comparisons with other methods considered for the same purpose.
(3) Detailes of used measuring system are also reported.
