# US 2019/0170549 A1 · Method for determining the time of flight of an ultrasound signal in a flowing medium and ultrasonic flow meter > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0170549 A1 - Document ID: US20190170549A1 - Status: Published application - Kind: A1 - Application number: 16/208,013 - Filed: 2018-12-03 - Published: 2019-06-06 - Earliest claimed: 2017-12-01 - Assignees: Diehl Metering GmbH - Applicants: Diehl Metering GmbH - Inventors: MARCUS WETZEL; ULRICH GAUGLER - Web page: https://patentgrep.com/patent/US20190170549A1 ## CPC - G01F 1/66: by measuring frequency, phase shift or propagation time of electromagnetic or other waves, e.g. using ultrasonic flowmeters - G01F 1/667: Arrangements of transducers for ultrasonic flowmeters; Circuits for operating ultrasonic flowmeters - G01N 29/024: by measuring propagation velocity or propagation time of acoustic waves - G01N 29/222: {Constructional or flow details for analysing fluids (optoacoustic fluid cells G01N29/2425)} - G01F: MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract A method for determining the time of flight, preferably the absolute time of flight, of an ultrasound signal in a flowing medium, includes using an ultrasound emitter to generate an ultrasound signal provided with a marker. The ultrasound signal is transmitted through the flowing medium to an ultrasound receiver, and the location of the marker is used in order to determine the time of flight of the ultrasound signal. The period duration of at least one selected period of the reception signal is measured to determine the location of the marker. An ultrasonic flow meter which can be operated according to the method is also provided. ## Claims ### Claim 1 A method for determining the time of flight of an ultrasound signal in a flowing medium, the method comprising the following steps: using an ultrasound emitter to generate an ultrasound signal provided with a marker; transmitting the ultrasound signal through the flowing medium to an ultrasound receiver; measuring a period duration of at least one selected period of a reception signal to determine a location of the marker; and using the location of the marker to determine the time of flight of the ultrasound signal. ### Claim 2 (depends on 1) The method according to claim 1, which further comprises opening a reception window to receive the reception signal, and establishing a location of the reception window as a function of a location of the selected period of the reception signal. ### Claim 3 (depends on 2) The method according to claim 2, which further comprises generating a plurality of reception signals by using a plurality of ultrasound signals, and displacing the position of the reception window until the marker of at least one of the reception signals lies inside the reception window. ### Claim 4 (depends on 3) The method according to claim 3, which further comprises additionally carrying out a displacement of the reception window as a function of a quality of the reception signal. ### Claim 5 (depends on 1) The method according to claim 1, which further comprises: using the ultrasound emitter to generate another ultrasound signal provided without a marker; transmitting the other ultrasound signal through the flowing medium to the ultrasound receiver and detecting the other ultrasound signal at the ultrasound receiver; and determining the location of the marker from a comparison of period durations of selected periods of the ultrasound signal with a marker and the other ultrasound signal without a marker. ### Claim 6 (depends on 5) The method according to claim 5, which further comprises providing the ultrasound signals with a marker and without a marker with an identical frequency. ### Claim 7 (depends on 5) The method according to claim 5, which further comprises using a difference between the ultrasound signals detected with and without a marker for allocating the emitted ultrasound signals to the received ultrasound signals. ### Claim 8 (depends on 5) The method according to claim 5, which further comprises emitting the ultrasound signals with and without a marker in an identical direction relative to a flow direction of the flowing medium. ### Claim 9 (depends on 5) The method according to claim 5, which further comprises providing the ultrasound signals with a plurality of periods. ### Claim 10 (depends on 1) The method according to claim 1, which further comprises setting the marker after an Nth period. ### Claim 11 (depends on 10) The method according to claim 10, which further comprises determining a location of a received wave period by using a difference in a period duration between the Nth and an N+1th period. ### Claim 12 (depends on 1) The method according to claim 1, which further comprises determining possible positions of the reception window, and repeating the method for a multiplicity of the possible positions of the reception window. ### Claim 13 (depends on 1) The method according to claim 1, which further comprises including a phase change of the ultrasound signal in the marker. ### Claim 14 (depends on 12) The method according to claim 12, which further comprises measuring a characteristic period duration for verification of the position of the reception window. ### Claim 15 (depends on 12) The method according to claim 12, which further comprises measuring a period duration of a period of the received ultrasound signals by using a single measurement. ### Claim 16 (depends on 1) The method according to claim 1, which further comprises determining an absolute time of flight of the ultrasound signals. ### Claim 17 An ultrasonic flow meter, comprising: an ultrasound emitter for generating an ultrasound signal provided with a marker; an ultrasound receiver for receiving the ultrasound signal transmitted through a flowing medium; and a measuring instrument for measuring a period duration of at least one selected period of a reception signal to determine a location of the marker used for determining the time of flight of the ultrasound signal.