| 摘要 |
PURPOSE:To discriminate the kind of steel non-destructively, easily and accurately, by detecting the contents of Si, Mn in accordance with an electric resistance value and magnetic permeability. CONSTITUTION:Low frequency measuring current is applied to the steel material sample 11 in a detecting section 3 by the probes P1, P2 in contact with said sample 11 via a signal transmitting section 1 and an electric power amplifying section 2. The voltage between the probes P3 and P4 in contact with the sample 11 is processed with a high input impedance amplifier 4 and a selective amplifier 5 which improves S/N by detecting only the frequency components and the voltage is detected in a synchronizing detecing section 6 formed of an analog switch, etc. The analog switch is controlled by a reference signal section 8, a phase section 9, and a reference signal driving section 10, and the component voltages proportional respectively to the resistance value and magnetic permeability of the sample 11 in the part corresponding to the required phase among the frequency components are detected. The DC voltages corresponding to the resistance value and magnetic permeability equivalent respectively to the contents of Si and Mn in the sample 11 are generated from an output amplifier 7, whereby steel kinds are decided easily and accurately without contacting. |
