You searched for: “electronic photometer
electronic photometer, photoelectric photometer
A photometer (instrument used for making measurements of light or electromagnetic radiation, in the visible range) which uses a photocell, a phototransistor, or a phototube to measure the intensity of light.
This entry is located in the following units: electro-, electr-, electri- (page 67) -tron, -tronic, -tronics + (page 11)