ULTRASONIC FLOW SENSOR WITH QUADRATURE DEMODULATION
First Claim
1. An ultrasonic flow sensor, comprising at least one ultrasonic converter for ultrasonic signals selected from the group consisting of an ultrasonic converter for transmitting ultrasonic signals an ultrasonic converter for receiving ultrasonic signals, and an ultrasonic converter for transmitting and receiving ultrasonic signals;
- an excitation unit connected with said ultrasonic converter;
an evaluation unit ascertaining a phase shift of a received ultrasonic signal relative to a parameter selected from the group consisting of a reference signal and a reference value, said evaluating unit including a plurality of quadrature demodulators which operate with different demodulation frequencies and each ascertain phase information about the ultrasonic signal that was received, and which includes a vernier unit that ascertains based on associated phase angles, a phase shift to be determined or a quantity proportional thereto.
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Accused Products
Abstract
An ultrasonic flow sensor, in particular for determining the flow velocity of a medium flowing through a pipeline, has at least one ultrasonic converter for transmitting and/or receiving ultrasonic signals, an oscillator, which is connected with the ultrasonic converter, and an evaluation unit, which determines a phase shift of the ultrasonic signal that was received, with respect to a reference signal. The evaluation unit includes a plurality of quadrature demodulators, which operate with different demodulation frequencies and each determine phase information about the ultrasonic signal that was received, and when a vernier unit is provided, which determines—based on the individual pieces of phase information—a phase angle or a quantity proportional thereto.
9 Citations
11 Claims
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1. An ultrasonic flow sensor, comprising at least one ultrasonic converter for ultrasonic signals selected from the group consisting of an ultrasonic converter for transmitting ultrasonic signals an ultrasonic converter for receiving ultrasonic signals, and an ultrasonic converter for transmitting and receiving ultrasonic signals;
- an excitation unit connected with said ultrasonic converter;
an evaluation unit ascertaining a phase shift of a received ultrasonic signal relative to a parameter selected from the group consisting of a reference signal and a reference value, said evaluating unit including a plurality of quadrature demodulators which operate with different demodulation frequencies and each ascertain phase information about the ultrasonic signal that was received, and which includes a vernier unit that ascertains based on associated phase angles, a phase shift to be determined or a quantity proportional thereto. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
- an excitation unit connected with said ultrasonic converter;
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11. A method for determining a transit time of an ultrasonic signal that was launched into a measurement path by an ultrasonic converter, comprising the steps of ascertaining a phase shift of the ultrasonic signal relative to a reference signal as a measure of a transient time;
- digitizing the ultrasonic signal received by a converter and supplying to a plurality of quadrature demodulators;
operating each of the quadrature demodulators with a demodulation signal of a different frequency;
ascertaining by each of the demodulators a phase information about the ultrasonic signal that was received; and
based on a specific phase information and using a vernier method, ascertaining a phase angle or a quantity proportional thereto.
- digitizing the ultrasonic signal received by a converter and supplying to a plurality of quadrature demodulators;
Specification