JPS54143259A - Ultrasonic flowmeter - Google Patents

Abstract

PURPOSE:To enable accurate measurement to be performed even for fluid of considerable fluctuations of the velocities of flow by alternately changing over acoustic wave pass direction in respectively forward and backward directions in a short time and separating the detection data obtained to each direction and using the same. CONSTITUTION:Driving signals are sent from an oscillator 2 through a changeover switch S1 to let pulse-form acoustic waves be radiated from an ultrasonic wave vibrator A1. These are then received in an ultrasnoic wave vdibrator A2 and the receiving pulses are sent to an amplifier 4 via changeover switch S2. A switch driving circuit 5 is driven by the output of the amplifier 4, by which the changeover switches S1, S2 are changed over. At this same instant, the driving pulses having been delayed for a fixed time are applied from a delay trigger circuit 6 to the oscillator 2. Since in this way the pulse-form acoustic waves are continuously and alternately passed in the fluid being measured in the forward and backward directions, the accurate measurement of flow rates may be accomplished even for the fluid of considerable fluctuations of the velocities of flow.