| 摘要 |
<p>In a metal body discriminating apparatus for discriminating the material, shape, size, or the like of a metal body, an oscillator performs a self-oscillating operation together with a coil wound like a ring provided to generate magnetic lines of force. Changes in frequency and amplitude of an oscillation signal in response to changes in impedance and inductance of the coil caused by an eddy current, which is generated in the metal body when the metal body moves through the coil, are detected as indicators of features of the metal body. Two or more of such coils may be arranged at regular intervals and the size of metal body will be discriminated based on signals having a phase difference which are obvious when the metal body passes sequentially through the coils.</p> |
