METHOD AND INSTRUMENT FOR ULTRASONICALLY MEASURING FLOW VELOCITY

摘要

PURPOSE: To measure the flow velocity of a fluid with high accuracy without receiving any influence from eddy and turbulent currents by simultaneously generating two ultrasonic signals from two points on the upstream and downstream sides of the same propagating route and measuring the propagating time of the signals. CONSTITUTION: A control section 41 simultaneously sends control signals to transmission-reception units 40 and 42 and sensor sections 15a and 15b simultaneously unit ultrasonic signals to an object through transmitting sections 43a and 43b and input-output circuits 45a and 45b. The control signals are also supplied to a counting section 49 so as to make the section 49 simultaneously start the counting of clock pulses. The received signals of the sensor sections 15a and 15b are supplied to the counting section 49 respectively through the circuits 45a and 45b and receiving sections 47a and 47b and separately stop the clock pulse counting operation of the section 49. As a result, the propagating time of the ultrasonic signals in the forward and reverse directions can be found. These time data are sent to an arithmetic processing section 51 and the section 51 calculates the flow velocity of a fluid from the propagating time in the forward direction and that in the reverse direction.