noun
: a spherical shell used to determine total luminous flux by means of photometric measurement of a spot of light through an aperture in the shell whose white interior produces thorough diffusion of light from a source placed at its center
noun
: a spherical shell used to determine total luminous flux by means of photometric measurement of a spot of light through an aperture in the shell whose white interior produces thorough diffusion of light from a source placed at its center
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012