Glossary · Sensors and measurement
Radar sensor
Also known as: Radar level sensor, Radar transmitter
German: Radarsensor
In industrial automation, a radar sensor is a sensor that emits electromagnetic waves in the microwave range and evaluates their reflection to measure distance, level, speed or presence of objects.
- Sensors
In one sentence
A radar sensor uses reflected microwaves to measure distance, level, speed or presence, largely unaffected by dust, steam and light.
Example
A radar level transmitter measures the level in a dusty cement silo where ultrasonic sensors fail.
How it applies
- Engineering: Free-space radar and guided-wave radar are standard for level measurement; radar sensors are also used for collision avoidance and speed measurement. Frequency band, beam angle and dielectric constant of the medium determine suitability.
- Commissioning: Tank internals and nozzles cause interference echoes. Commissioning includes setting the tank geometry and suppressing false echoes.
- Compliance: Radar devices are radio equipment, and national and EU radio regulations apply to their use, for example restrictions on use outside closed tanks for some frequency bands. Check the manufacturer's approvals.
- Documentation: Record configuration parameters and the echo curve at commissioning; it is a valuable reference for later troubleshooting.
Radar sensor vs. ultrasonic sensor
Radar uses electromagnetic waves and is largely unaffected by temperature, pressure, vapors and dust. An Ultrasonic sensor uses sound waves, which depend on the gas and temperature and are damped by foam and dust.