Patent ID: 6911818

Claim:
A method for evaluating measuring signals of an electromagnetic field which is in interaction with an electrically conductive fluid for detecting components in the fluid which differ with respect to the electric conductivity of the fluid, characterized in that the measuring signals are divided into at least two channels and are evaluated in order to detect different distributions and concentrations in the fluid, characterized in that the electromagnetic field is generated by at least one transmitter coil flowed through by an alternating current, the fluid is a flowing metallic melt and is penetrated at least partly by the field at a measuring point flowed through by the melt and entrained non-metallic components are detected at the measuring point by means of disturbances in the field, with non-metallic components which are entrained in a contiguous fashion in a manner expanded in a direction of flow of the melt being detected in the melt on the basis of disturbances in the electromagnetic field in a first channel above a lower cut-off frequency f Go and simultaneously components distributed discretely in the melt being detected in the melt in a second channel above an upper cut-off frequency f Go .