| 摘要 |
PURPOSE:To enable rapid measurement, by calculating the difference between the output voltage between a pair of impedances and that between a pair of probe coils by a differential amplifier and measuring the content of silicon contained in pig iron samples inserted in a pair of the probe coils corresponding to the voltage outputted from the differential amplifier. CONSTITUTION:Pig iron samples S1, S2 equal in silicon content are inserted in a pair of probe coils 2a, 2b same in a winding width and the number of windings and the output voltage of a differential amplifier 5 comes to zero volt by regulating the valves of impedances 3a, 3b of an AC bridge circuit 4. For example, when the sample S2 of the coil 2b is taken out and an pig iron sample unknown in silicon content is inserted in said coil 2b in this state, the impedance of the coil 2b changes and, therefore, the balance of the circuit 4 is brought to a non-equilibrium state and output voltage E0 proportional to the imbalance is obtained in the amplifier 5 to be sent to a synchronous detector 7 and converted to DC voltage E0 which i, in turn, amplified to a predetermined value by an amplifier 8 and recorded by a recorder. |
