To produce cement, the raw meal is burned to clinker in a long rotary kiln. After leaving the rotary kiln, the clinker has a temperature of up to +1300 °C and must be cooled down to a temperature of about +200 °C for further storage. To achieve this, the clinker bed is cooled with a continuous stream of air. Pressure monitoring is required in the lower part of the clinker cooler to make the cooling as effective as possible. The material height of the hot clinker, at over 1000 °C on the conveyor belt, also has to be reliably measured.