Patent ID: 9304225
Filing Date: 2016-04-05
CPC Classification: G01V

Claim Text:
1. Method for locating and/or identifying metallic or metal-containing objects and materials, comprising a coil arrangement in which a transmission coil and a reception coil are arranged over one another, wherein the reception coil generates a reception coil output signal, comprising a closed-loop compensation regulation of the reception coil output signal for compensation of changes in the reception coil, said changes occurring in a detection region of the reception coil and influencing the reception coil, wherein compensation currents are fed into a receiving branch of the reception coil and are regulated relative to one another by means of regulating values such that the reception coil output signal or average values acquired from the reception coil output signal after demodulation are continuously regulated to zero relative to one another, even under influence of a metal, wherein the regulating values are evaluated in order to locate and/or identify the metallic or metal-containing objects and materials.