Flow Tronic "Innovative Radar Sensors in Environmental Measurements"

Aim of this project is the development of a sensor for contactless flow velocity measurements of fluids possibly carrying solids like it is the case, e.g., in sewer pipes. The sensor’s operating range should allow sensor mounting heights between 0 m and 10 m above the liquid level (the height of typical applications is usually below 5 m). Velocities between 0.2 m/s up to 6 m/s should be covered with an accuracy of approx. 1%. For this purpose radar was selected as sensing principle because of its robustness even under harsh environmental conditions. The operating frequency was chosen to be 24 GHz, which is a compromise between required sensor size (which decreases with rising frequency) and the availability of off-the-shelf RF building blocks and therefore manufacturing costs. Since the frequency range between 24 GHz and 24.25 GHz is a so-called industrial, scientific and medical (ISM) radio band, unlicensed operation of the sensor is allowed. The available bandwidth of 250 MHz is large enough so that an operation without complex frequency stabilization should be possible.