Core shooting machines produce sand cores for metal foundry. Since the removal of the cores and the following machine restart has been automated, it must be ensured that the sand reservoir is sufficiently supplied. Ultrasonic sensors from Balluff measure the levels of these sand reservoirs continuously and without contact. They are unaffected by dust or dirt and can detect objects at greater distances. Their high resolution and small blind zones mean they are extremely precise. The levels can be output either as an analog measurement or by configuring two switching signals as min and max values.