Ultrasonic Sensors

Ultrasonic Sensors are transducers that convert ultrasound waves to electrical signals or vice versa. Those that both transmit and receive may also be called ultrasound transceivers; many ultrasound sensors besides being sensors are indeed transceivers because they can both sense and transmit. These devices work on a principle similar to that of transducers used in radar and sonar systems.

The four sensor types of ultrasonic sensors:

Ultrasonic proximity sensors
Ultrasonic 2 point proximity switches
Ultrasonic retro-reflective sensors
Ultrasonic through beam sensors