JPS5527937A - Ultrasonic wave flow meter - Google Patents

Abstract

PURPOSE:To provide the subject meter wherein the correlation between a signal applied to a sender and a signal received from a receiver is utilized thereby to improve the measuring accuracy. CONSTITUTION:An oscillator 19 is connected to a ultrasonic sender 20 provided in a pipe 21 and a variable delay circuit 25, and a multiplier 26 connected directly to a variable delay circuit 25 and through an amplifier 24 to a ultrasonic wave receiver 23 is connected through an integrator 27 to a meter 29. As a result, a sending signal generated from the oscillator 19 is propagated in a fluid 22 through a ultrasonic wave sender 20, and propagation loss is compensated by the amplifier 24. Thereafter, the sending signal is supplied as input to the multiplier 26 and delayed to obtain the correlation with the receiving signal for the required time, and thereafter supplied to the multiplier 26, where the output of the multiplier 26 is integrated and the output affording the output affording the output maximum value is detected, the time up to the output maximum value being indicated as a flow rate of the fluid 22 in the meter 29, the flow quantity being measured since the sectional area of the pipe 21 is clear.