| 摘要 |
PURPOSE:To remove various noises thoroughly and to obtain only the desired signal components by providing an arithmetic control circuit, performing prescribed sampling, and setting and processing the signals so as to make the respective noises zero. CONSTITUTION:Electrodes 3a, 3b are mounted to an insulation conduit 2 through which the magnetic field generated by an energizing coil 1 passes. The electrodes 3a, 3b are connected to the two input terminals of a differential amplifier 6 via buffer amplifiers 4, 5. The next step of the amplifier 6 is connected via an A/D conversion circuit 8 to an arithmetic control circuit 9. In this circuit 9, sampling of signals and signal processing in accordance with this are accomplished. DC noises, electromagnetic induction noises and further commercial frequency noises exist other than the desired signals in the signals from the electrodes 3a, 3b. These signals are sampled at prescribed timings, after which they are arithmetically processed in the circuit 9, and are outputted as noiseless flow rate signals. Thereby, only the signal components removed thoroughly of the noises are obtained. |
