Glossary · Sensors and measurement
Ultrasonic sensor
Also known as: Ultrasonic transducer
German: Ultraschallsensor
In industrial automation, an ultrasonic sensor is a sensor that emits sound pulses above the audible range and measures the time until the echo returns, to detect objects or measure distance and level without contact.
- Sensors
In one sentence
An ultrasonic sensor measures distance or detects objects from the echo time of sound pulses, independent of color and transparency.
Example
An ultrasonic sensor detects transparent plastic bottles on a conveyor that photoelectric sensors cannot see reliably.
How it applies
- Engineering: Ultrasonic sensors detect objects independently of color and transparency. The speed of sound depends on gas temperature and composition, so sensors compensate for temperature. Foam, dust, vapors and soft surfaces weaken the echo.
- Commissioning: Every sensor has a blind zone near the transducer where it cannot measure. Set the measuring window and check for interfering echoes.
- Operation: Multiple sensors near each other can interfere; synchronization or multiplexing prevents this.
- Documentation: Specify blind zone, beam angle and environmental limits in the operating manual and note the effect of foam or dust on level readings.
Ultrasonic sensor vs. radar sensor
An ultrasonic sensor is inexpensive and works well in clean conditions. A Radar sensor is less affected by vapors, pressure, temperature and dust and is preferred for demanding level measurements.