Universal doppler flowmeter tester
AssigneeManning Technologies, Inc.
InventorAlvin E. Brown
Life of this patent
Estimating the term…
Abstract
A circuit simulating the electrical signal response of a flowing liquid whose velocity is to be measured by a Doppler flowmeter. The circuit takes the electrical flowmeter transmit signal from a Doppler flowmeter and modifies its frequency to derive a simulated Doppler shifted signal. The latter signal is used to modulate the transmit signal in a double side band, balanced modulator which suppresses the frequency of the transmit signal and produces upper and lower side band frequencies mimicking a Doppler shifted return signal. The latter signal is fed to the signal receiving transducer of a Doppler flowmeter for test purposes.
Claims16
A circuit simulating the electrical signal response of a flowing fluid whose velocity is to be measured by a Doppler flowmeter having an electrical-to-acoustic energy transducer acting as a signal transmitter and the same or another transducer acting as a signal receiver comprising,
- input means for acquiring an electrical Doppler transmit signal from a Doppler flowmeter, said transmit signal having a transmit frequency,
- circuit means, connected to said input means, for modifying said transmit frequency by a preselected amount to produce a simulated Doppler shifted signal,
- modulator means communicating with said input means and said circuit means for modulating the Doppler transmit signal with the simulated Doppler shifted signal in a manner producing frequencies above and below the transmit frequency, forming a Doppler shifted return signal, and
- output means for delivering the Doppler shifted return signal from said modulator means to a Doppler signal receiver.
A circuit simulating the electrical signal response of a flowing fluid whose velocity is to be measured by a Doppler flowmeter having an electrical-to-acoustic energy transducer acting as a signal transmitter and the same or another transducer acting as a signal receiver comprising,
- electrical signal input and output means for respectively acquiring and delivering an electrical Doppler transmit signal from and to a Doppler flowmeter, said transmit signal having a transmit pulse frequency,
- a pulse frequency multiplying means for receiving said transmit pulse frequency and modifying said transmit pulse frequency by a preset amount thereby forming a simulated Doppler shifted pulse signal,
- a wave shaping circuit means connected to receive said Doppler shifted pulse for converting pulses to approximate sine waves thereby forming a simulated Doppler shifted sine wave signal, and
- modulator means communicating with said input and output means and said wave shaping circuit means for modulating the Doppler transmit signal with the simulated Doppler shifted sine wave signal producing frequencies above and below the transmit pulse frequency thereby producing a Doppler shifted return signal at said output means.
A method for electrically simulating the flow of fluid in a pipe for flow velocity measurement by a Doppler flowmeter comprising,
- acquiring an electrical signal being fed to the electrical-to-acoustic energy transducer of a Doppler flowmeter having a characteristic transmit frequency,
- electrically modifying the characteristic transmit frequency signal to produce a simulated Doppler shifted signal,
- modulating the transmit frequency signal with the simulated Doppler shifted signal producing signals with frequencies above and below the transmit frequency thereby producing a Doppler shifted return signal, and
- applying the Doppler shifted return signal to a Doppler flowmeter receiving transducer.
Dependencies are inferred from the claim text.