MEASURING APPARATUS AND METHOD FOR DETECTING ELECTRICALLY CONDUCTIVE ELEMENTS IN PRODUCTS AND A MACHINE FOR PRODUCING PRODUCTS OF THE TOBACCO-PROCESSING INDUSTRY

摘要

The present invention relates to a measuring apparatus for detecting electrically conductive elements (34, 44, 51) in a material stream (31, 41) or strand (50) or a rod-shaped article of the tobacco-processing industry, comprising at least one transmitter which, in the region of the material stream or strand or in the rod-shaped article, builds up an electromagnetic field which increases a detection certainty for metal objects by virtue of the transmitter (20, 32) producing a high-frequency magnetic field (21) which induces eddy currents (23) in the electrically conductive element (34, 44, 51) in the material stream (31, 41) or strand (50) or rod-shaped article; at least one receiver (24, 33) is also provided and measures the attenuation and/or amplification of the high-frequency magnetic field by the induced eddy currents (23), and a device (46, 47) which is coupled to the receiver (24, 33) and is intended to evaluate the measurement results from the receiver (24, 33). The present invention also relates to a method and a machine having such a measuring apparatus.