Abstract An ultrasonic current meter having an ultrasonic transmitter, an ultrasonic receiver, an oscillator for supplying a signal of a predetermined frequency to the ultrasonic transmitter to emit ultrasonic waves therefrom, a circuit for generating a signal of a Doppler frequency by combining a signal corresponding to the ultrasonic waves reflected by objects contained in a fluid to be measured but different in acoustic impedance from the fluid with a signal derived from the oscillator and an indicator device for indicating the flow rate of the fluid in accordance with the signal of the Doppler frequency, in which the ultrasonic transmitter and receiver have devices for controlling the ultrasonic waves transmitted and received mounted adjacent the transmitter and receiver, respectively, thereby to ensure accurate measurement of the flow rate of the fluid.
An ultrasonic current meter comprising an ultrasonic transmitter, an ultrasonic receiver, a first means for supplying a signal to the ultrasonic transmitter to emit ultrasonic waves therefrom, a second means for producing a signal of a Doppler frequency by combining a signal corresponding to the ultrasonic waves reflected by objects contained in a fluid to be measured but different in acoustic impedance from the fluid with a signal derived from the first means, a means for receiving the signal of the Doppler frequency to indicate the flow rate of the fluid, the ultrasonic transmitter and receiver having mounted in front thereof means for controlling the ultrasonic waves transmitted from the former and received by the latter respectively, the ultrasonic waves controlling means mounted in front of the ultrasonic transmitter and receiver changing the directions of the ultrasonic beams of the transmitter and receiver in response to temperature changes of the fluid, thereby to ensure accurate measurement of the flow rate of the fluid.
Claim 2
Dependent Claim
163 words
An ultrasonic current meter comprising an ultrasonic transmitter, an ultrasonic receiver, a first means for supplying a signal to the ultrasonic transmitter to emit ultrasonic waves therefrom, a second means for producing a signal of a Doppler frequency by combining a signal corresponding to the ultrasonic waves reflected by objects contained in a fluid to be measured but different in acoustic impedance from the fluid with a signal derived from the first means, a means for receiving the signal of the Doppler frequency to indicate the flow rate of the fluid, the ultrasonic transmitter and receiver having mounted in front thereof means for controlling the ultrasonic waves transmitted from the former and received by the latter respectively, the ultrasonic waves controlling means mounted in front of the ultrasonic transmitter and receiver changing the directions of the ultrasonic beams of the transmitter and receiver in response to temperature changes of the fluid, thereby to ensure accurate measurement of the flow rate of the fluid.
Claim 3
Dependent Claim
18 words
An ultrasonic current meter as claimed in claim 1 wherein the ultrasonic wave controlling means are prism means.