| 摘要 |
PURPOSE:To enable flow rate measurement to be performed accurately with a simple constitution even for fluid of considerable fluctuations of the velocities of flow by simultaneously driving a pair of ultrasonic wave vibrators to mutually backward receiving acoustic waves and allowing the acoustic waves to pass simultaneously in the opposite directions with respect to the fluid being measured. CONSTITUTION:Driving signals from a driving circuit 2 are applied to a pair of ultrasonic wave vibrators A1, A2 to radiate ultrasonic waves simultaneously and have these received in respectively reciprocal other ultrasonic wave vibrators A2, A1, whereby the receiving signals are applied respectively to forward, backward receiving discrimination circuits 3, 4. The signals having been applied to the forward, backward receiving discrimination circuits 3, 4 are mutually compared and evaluated of voltage levels, disturbance of waveforms, the degrees of attenuation, etc. and if they satisfy the preset conditions, they are employed as normal signals and if not, they are excluded as abnormal signals. Since only the normal signals empolyed are sent to a signals processing circuit 6, the measurement of the velocities of flow of the fluid being measured of considerable fluctuations in the velocity of flow is accurately accomplished. |
