DETECTING DEVICE OF METAL

摘要

PURPOSE:To remove a noise component which a substance to be inspected itself has. CONSTITUTION:A detecting device of a metal which is equipped with an oscillation coil and a reception coil 2 and with a means for amplifying a potential difference induced in the reception coil 2. This device is featured by that an arithmetic means for preparing a signal having a phase difference of pi/2 from an output signal of the amplifying means generated when a substance 3 to be inspected in which no metal is contained passes through a magnetic field and a means for detecting the output signal of the amplifying means with an output signal of the arithmetic means used as a reference signal are provided.