To lower expenses for a measuring apparatus and to measure a precise illuminance distribution simply even when a space is wide and an optical environment is unstable in a measuring method for an illuminance distribution in a prescribed space.
A reflecting object 20 which comprises a uniform difuse reflecting face is installed at every measuring point, the luminance of reflected light from the reflecting face is measured in every measuring point, and an illuminance in every measuring point is computed on the basis of a luminance measured value in every point and on the basis of the reflectance of the uniform diffuse reflecting face. Since an illuminance in a point and the luminance of reflected light from a reflecting face arranged in the point are in a theoretically linear relationship, the illuminance can be computed on the basis of the measured value of the luminance. In addition, since the time required for measuring a luminance by a luminance meter 30 is shorter than the time required for measuring an illuminance by an illuminance meter, a measuring time difference between respective measuring points can be shortened.
HAMADA YUKIKO
GOTO CHIKAKO
NISHIMURA MASAKAZU
