Photometer

Chamber's Twientieth Century Dictionary · 1908 · p. 77

fō-tom′e-tėr, n. an instrument for measuring the intensity of light, esp. for comparing the amount of light coming from different sources.— adjs. Photo met′ric , -al .— n. Photom′etry , the measurement of the intensity of light. [Gr. phōs , phōtos , light, mētron , a measure.]