| 摘要 |
PURPOSE:To enable the measurement of the two-dimensional position and sectional shape of a metallic material with high accuracy by providing one electorde ring and plural pieces of curved electrode plates and measuring electrostatic capacity. CONSTITUTION:An AC oscillator 21 is connected to the electromagnetic ring 11 of a detector 10, and the rings 11 and 12 form an electrostatic capacitor through a dielectric material. The electric current of the oscillator 21 flows as displacing current into the ring 12 and the displacing current is detected and amplified by an AC amplifier 22. The displacing current is large as the sectional area of a metallic material 50 to be measured is small and is small when the sectional area is large. The displacing current of the amplifier 22 is converted to a voltage which is inputted to a filter 23. The voltage of a required frequency component is extracted from said filter and is inputted to an AC/DC converter 24 which converts the voltage to a DC voltage and outputs the voltage/current signal proportional to the sectional area. The measurement of the sectional area. The measurement of the sectional area of the metallic material without contact therewith is made possible by such measurement of the electrostatic capacitor. Since such an operation for rotating the measuring device is not necessary, the measurement is accomplished with ease. |
