Ultrasonic measuring apparatus
First Claim
1. In an ultrasonic measuring apparatus of the type having a pair of transducers disposed oppositely on a pipe through which a fluid to be measured flows and which are so controlled alternately as to convert an input electrical signal to an acoustic signal and to convert a received acoustic signal to a received electrical signal, oscillating means for generating an oscillator output signal having a variable frequency, a counter for counting said oscillator output signal to produce a counter output signal when the count value of said counter reaches a predetermined value, a delay means for delaying said counter output signal and producing a delayed output signal, a transmitter receiving said oscillator output signal for producing said input electrical signal, a time difference detecting means for receiving said delayed output signal and said received electrical signal for detecting the time difference between said delayed output signal and the propagating time required for an ultrasonic wave to propagate through said fluid to be measured, controlling means for controlling the frequency of said oscillating means so as to make said time difference zero, and means for detecting said propagating time in accordance with the frequency of said oscillating means, said ultrasonic measuring apparatus comprising:
- comparing means for comparing a voltage signal corresponding to said time difference with first and second set voltages; and
monitoring means receiving the comparison result from said comparing means for judging whether said fluid flow is propagated in said pipe in a normal condition or in an abnormal condition.
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Accused Products
Abstract
An ultrasonic measuring apparatus of the type having a pair of transducers disposed oppositely on a pipe through which a fluid to be measured flows and which are so controlled alternately as to convert an input electrical signal to an acoustic signal and to convert a received acoustic signal to a received electrical signal. The apparatus includes a time difference detecting means for receiving an output signal from a delay means and the received electrical signal for detecting a time difference between a delayed counting time obtained from the delay means and a propagating time required for an ultrasonic wave to propagate through the fluid to be measured. Comparing means are provided for comparing a voltage signal corresponding to the time difference with first and second set voltages and monitoring means receiving the comparison result from the comparing means for judging whether the fluid flow is propagated in the pipe in a normal condition or in an abnormal condition. The present invention ensures a quick detection of abnormal propagation of the ultrasonic wave in the pipe and obtains a correct measurement values without misjudgement.
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Citations
13 Claims
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1. In an ultrasonic measuring apparatus of the type having a pair of transducers disposed oppositely on a pipe through which a fluid to be measured flows and which are so controlled alternately as to convert an input electrical signal to an acoustic signal and to convert a received acoustic signal to a received electrical signal, oscillating means for generating an oscillator output signal having a variable frequency, a counter for counting said oscillator output signal to produce a counter output signal when the count value of said counter reaches a predetermined value, a delay means for delaying said counter output signal and producing a delayed output signal, a transmitter receiving said oscillator output signal for producing said input electrical signal, a time difference detecting means for receiving said delayed output signal and said received electrical signal for detecting the time difference between said delayed output signal and the propagating time required for an ultrasonic wave to propagate through said fluid to be measured, controlling means for controlling the frequency of said oscillating means so as to make said time difference zero, and means for detecting said propagating time in accordance with the frequency of said oscillating means, said ultrasonic measuring apparatus comprising:
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comparing means for comparing a voltage signal corresponding to said time difference with first and second set voltages; and monitoring means receiving the comparison result from said comparing means for judging whether said fluid flow is propagated in said pipe in a normal condition or in an abnormal condition. - View Dependent Claims (2, 3)
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4. In an ultrasonic measuring apparatus of the type having a pair of transducers disposed oppositely on a pipe through which a fluid to be measured flows and which are so controlled alternately as to convert an input electrical signal to an acoustic signal and to convert a received acoustic signal to a received electrical signal, oscillating means for generating an oscillator output signal having a variable frequency, a counter for counting said oscillator output signal to produce a counter output signal when the count value of said counter reaches a predetermined value, a delay means for delaying said counter output signal and producing a delayed output signal, a transmitter receiving said oscillator output signal for producing said input electrical signal, a time difference detecting means for receiving said delayed output signal and said received electrical signal for detecting the time difference between said delayed output signal and the propagating time required for an ultrasonic wave to propagate through said fluid to be measured, controlling means for controlling the frequency of said oscillating means so as to make said time difference zero, means for emitting said ultrasonic wave into said fluid in a forward direction and in a backward direction with respect to the direction of the flow of said fluid in an alternately repeated manner, and means for measuring the flow speed or flow rate of said fluid in accordance with the frequency difference between the oscillating frequencies when said ultrasonic wave is emitted in said forward direction and when said ultrasonic wave is emitted in said backward direction, said ultrasonic measuring apparatus comprising:
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a comparator for judging whether a first voltage signal corresponding to the time difference when said ultrasonic pulse is emitted in said forward direction and a second voltage signal corresponding to the time difference when said ultrasonic pulse is emitted in the backward direction, respectively, fall within a predetermined voltage range; and a register for judging whether said first and second voltages fall within said predetermined voltage range in succession, thereby monitoring from an output of said register whether the ultrasonic pulses emitted in the forward and backward direction in succession are propagated normally or not. - View Dependent Claims (5, 6, 7, 8, 9, 10, 11, 12, 13)
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Specification