photoelectric cell
121photocell — n. electric eye, photoelectric cell, device that uses light to regulate or produce an electrical current …
122photocells — n. electric eye, photoelectric cell, device that uses light to regulate or produce an electrical current …
123ceilometer — An instrument to measure the heights of clouds during the day. The ceilometer beams a light at the cloud base, which it detects by a photoelectric cell. A process of triangulation then determines the height of the cloud. Cloud ceilometer …
124electric eye — noun informal a photoelectric cell operating a relay when the beam of light illuminating it is obscured …
125magic eye — noun 1》 informal a photoelectric cell or similar electrical device used for detection or measurement. 2》 a small cathode ray tube in some radio receivers that displays a pattern which enables the radio to be accurately tuned …
126photocell — noun short for photoelectric cell …
127photomultiplier — noun an instrument containing a photoelectric cell and a series of electrodes, used to detect and amplify very faint light …
128electric eye — noun (C) informal a photoelectric cell …