“SlideControl” enables continuous flow measurement of all materials conveyed in air slides, e. g. limestone meal, cement, alumina, phosphates. In its standard version, the system can be used to a material temperature of 80 °C, but an optional system is available for up to 120 °C. For the installation a mounting plate must be simply fixed to the top section of the air slide. Here there are two receivers in the form of Jacobs sockets. One is used for the sensor, the other for optical monitoring. The measurement principle is based on two independent measurements. With the help of a correlation process, the flow rate of the material is recorded with two electrodes at the bottom of a fin. Another electrode over the entire length of the fin is used to measure the filling height in the slide (Fig.). These two readings plus the known and constant width of the slide are combined to calculate the volume flow rate, which is transmitted as a signal.