1. LEGO Robotics Ultrasonic Sensor

2. Ultrasonic Sensor
An ultrasonic sensor works with waves and it is often used in applications for measuring distance between a robot and surrounding objects.
The ultrasonic sensor emits sound waves and receives their echoes to detect and measure the distance to one or more objects.
It can also listen for a sound wave which can be used to trigger programed event/s.

3. Ultrasonic Sensor
The Ultrasonic Sensor can function as a sonar by sending out single sound waves and listening for their returns.
The Ultrasonic Sensor generates sound waves and reads their echo returns to detect and measure the distance to objects.
The newest EV3 Ultrasonic Sensor can be used as a passive or active sonar.
The EV3 Ultrasonic Sensor is designed for a wide range of applications including here measure the distance, detection, or traffic monitoring

4. Ultrasonic Sensor
Measures distances between one and 250 cm (approximately 100 in.)
Accurate to +/- 1 cm (+/ in.)
Front illumination is constant while emitting and blinks while listening
Returns true if other ultrasonic sound is recognized