plural of detectograph

An early audio recording device used in wiretaps.

A device used in security systems that can alert the user of the presence of a moving object.

(archaic) second-person singular simple present form of detect

(historical) An apparatus for recording the time when a watchman visits a station on his rounds.

plural of time detector

A timepiece provided with a device for registering and indicating the exact time when a watchman visits certain stations on his beat.

(railways) A bar, connected with a switch, longer than the distance between any two consecutive wheels of a train, laid inside a rail and operated by the wheels so that the switch cannot be thrown until the entire train has passed the switch.

plural of detector bar

plural of motion detector