visual photometer


visual photometer

[′vizh·ə·wəl fə′täm·əd·ər] (optics) A photometer in which the luminance of two surfaces is compared by human vision; it usually utilizes the Lummer-Brodhun sightbox or some adaptation of its principles.

photometer

Any instrument that measures photometric quantities such as luminance, luminous intensity, luminous flux, and illumination.