Abstract: A device for detecting a knocking in an internal combustion engine has an evaluating facility, a knock sensor for sensing knocking of an internal combustion engine and producing output signals of the knocking sensor, an evaluation facility for obtaining the filtered signals from the filter from the devices and evaluating the same and a device for controlling a center frequency of at least one of the filter devices depending on at least one operating parameter of the internal combustion engine.

Abstract: A knock sensor for indirect or direct fixing to an internal combustion engine has a housing (10) with a pressure sleeve (11) on the outer side of which a piezoceramic disk, a seismic mass (16), the contact disks (14), and the insulating disks (13) are arranged. The insulating disks (13) or the piezoelectrical disk (15) are or is made slightly electrically conductive so that the voltage spikes which occur due to the pyroelectrical effect can be easily eliminated. In this way, faulty measuring and interference can be avoided in the electrical circuit connected to the knock sensor.