Level Measurement with Radar sensors
Electromagnetic waves form the basis of level measurement with radar. A radar sensor emits a focussed electromagnetic wave that is reflected by objects as an echo and is then evaluated by the sensor. In addition to free-radiating radar sensors, the radar category also includes those based on guided microwave technology, which are referred to as guided radar, TDR (time domain reflectometry) or also GWR (guided wave radar) sensors.
The fundamental difference between free-radiating and guided radar sensors is the way the electromagnetic waves reach the medium to be measured. While free-radiating radar sensors use special types of antennas to transmit the waves in the direction of the material without contact, guided radar sensors require a probe (rod or cable) as a waveguide along which the signal is guided to the medium. The probe is in contact with the medium.
Free-radiating radar sensors are generally characterized by their frequency, since this is important for non-contact level determination in process or storage vessels. Radar sensors with high frequencies can be built more compactly, have smaller radiation angles and better reflection properties, which ultimately leads to precise and reliable measurement results. Therefore, UWT's free-radiating radar sensors also work with 80 GHz technology.
Guided radar sensors, on the other hand, can measure at a much lower frequency (1 GHz) due to their function, which in turn offers advantages in the case of dust, adhesions, foam, steam or moving surfaces. As a result, guided radar sensors can also be used for interface measurement. Another important component of guided radar sensors is the probe. Here, different variants are available depending on the application. UWT offers sensors with rod probes, cable probes, coated cable probes (PA) and coaxial probes in order to have the right solution for every application.