método para operar um sistema de detecção de metal e um sistema de detecção de metal

摘要

A method for operating a metal detection system that comprises a balanced coil system. One embodiment of the method comprises: determining the phase and magnitude of related signals at least for a first metal contaminant for at least two transmitter frequencies and for at least two particle sizes of the first metal contaminant; determining the phase and magnitude of the related signal for a specific product for the at least two transmitter frequencies; comparing information established at least for the first metal contaminant and the information established for the product; determining a transmitter frequency with which signal components of smallest sized particles of the at least first metal contaminant differ sufficiently or most in phase and amplitude from the phase and amplitude of the product signal; and selecting the transmitter frequency for measuring the product. A metal detection apparatus adapted to operate according to an exemplary method is also provided.