The first practical application is directed at plastic or rubber mixing roller mills. So far, one way to protect an operator are rods above the two rollers. The safety provided by this method is considered sufficient. Depending on the processed material, it occurs that the material forms waves which touch the safety rods and thus stops the machine. In other words, some materials cannot be processed when these safety rods are in use. In this case, the safety measures will be discarded. The approach with a capacitive sensor is the only one to distinguish between the nonconductive material and a human arm.
The following figure is taken from the recommendations of the BG RCI, a part of the German Social Accident Insurance, to protect roller mills with roller diameters up to 400 mm. (For the exact reference, see the German text, please.)
The final photographs show the test setup at the IFA. The BG RCI will set these capacitive switching rods as standard once such products are available.