Guided Wave Tank Level Sensor

A radar based precise level gauging sensor for fuel tanks is presented in this paper. Multi-target scenarios and multipath propagation are avoided by guiding the radar signal in a waveguide. The distance to the fuel level within the waveguide is detected with a low-cost frequency-modulated continuous-wave radar sensor. The accuracy of the sensor is increased by winding the waveguide to a helix. At the bottom of the tank the inclination of half a winding is zero. This locally separates the reflection at the short of the waveguide from the reflection at the fuel surface.