The system is based on the reflection of an electromagnetic pulse that is directed on a sensor rod/ cable and reflected by filling material. The electronics integrated into the sensor determines the filling state from the echo time of the pulse and shows this in the display.
The electromagnetic pulse is sent out, reflected on the filling material and received again. The echo time of the pulse is proportional to the distance from the surface of the medium. The measurement procedure and the accuracy of the measurement are independent of pressure, temperature, vapor, dust, foam, viscosity, conductivity and pH value.