phototube
/ˈfoʊtoʊˌtub/
noun
- An electronic device that converts light into an electrical signal, used in sensors and light detection equipment.
- The old movie projector used a phototube to read the soundtrack from the film strip.
- A phototube in the streetlight detects when it gets dark and turns the light on.
- Engineers replaced the broken phototube in the automatic door sensor so it would open when someone approached.
Synonyms