phototubes
/ˈfoʊtoʊˌtubz/
noun
- Plural of phototube; multiple electronic devices that convert light into electrical signals.
- The technician tested all the phototubes in the array to ensure they responded to infrared light.
- The laboratory had several phototubes arranged to measure light from different angles.
- Old security systems used phototubes to detect when a beam of light was broken.