LIGHT RECEIVING PART OF ILLUMINOMETER

摘要

PURPOSE:To allow the spectral sensitivity of a light receiving part to coincide with standard relative luminosity with good accuracy, by a method wherein the opening of a light blocking support plate fixing a relative luminosity correction filter on the incident side thereof is made larger than that on the emitting side thereof and a rod- shaped filter made different in transmissivity according to a wavelength is inserted in the opening on the incident side to change a constitutional ratio. CONSTITUTION:A light blocking support plate 2 has columnar openings and the diameter phib of each of said openings on the incident side thereof is larger than the diameter phia thereof on the emitting side thereof. Therefore, the brightness irregularity of a light diffusion plate 4 for correcting an oblique incident angle characteristic or the change in the spectral distribution on the emitting side due to the direction of diffused light are removed. A relative luminosity correction filter 1 is constituted of plural kinds of filters different in spectral transmissivity and, when the constitutional ratio of plural sensitivity of a light receiving part can be finely adjusted and the irregularity of the spectral sensitivity of a light receiver generated by the irregularity of the spectral sensitivity of a photoelectric converter element 3 and that of the spectral transmitting characteristic of the relative luminosity correction filter 1 can be corrected.