Basic Principle of Ultrasonic Distance Sensors

Ultrasonic distance sensors measure distance by using the propagation speed of ultrasound in air to determine the distance between the sensor and a target object.

The principle is:

1. Emission: the sensor emits an ultrasonic pulse (typically above 20 kHz).

2. Reception: the pulse reflects off the target and returns to the sensor.

3. Calculation: measure the round-trip time and multiply by sound speed in air (~340 m/s) to compute distance.

Measurement range and accuracy depend on factors such as frequency, sensor design and target surface properties. Ultrasonic sensors are widely used in industry, automation and robotics for distance measurement and obstacle detection.