Abstract: Ultrasonic flowmeter for measuring the flowrate of a fluid based on transit times of opposite propagating ultrasonic wave packets, including two ultrasonic transducers arranged at a flow tube for transmitting and receiving the ultrasonic wave packets through a fluid; a control circuit configured for operating the ultrasonic transducers to transmit and receive co-propagating and counter-propagating ultrasonic wave packets, and to determine transit times between transmission and reception of the ultrasonic wave packets; wherein the control circuit is further configured to continuously determine the flowrate of the fluid based on sequential application of separate flow measurement sequences and flow estimation sequences, the flow measurement sequence including transmitting and receiving a co-propagating wave packet and a counter-propagating wave packet, determining a transit time difference between the co-propagating and the counter-propagating wave packets, determining the speed of sound in the fluid, and calcu

Abstract: Ultrasonic flowmeter for measuring the flowrate of a fluid based on transit times of opposite propagating ultrasonic wave packets, including two ultrasonic transducers arranged at a flow tube for transmitting and receiving the ultrasonic wave packets through a fluid; a control circuit configured for operating the ultrasonic transducers to transmit and receive co-propagating and counter-propagating ultrasonic wave packets, and to determine transit times between transmission and reception of the ultrasonic wave packets; wherein the control circuit is further configured to continuously determine the flowrate of the fluid based on sequential application of separate flow measurement sequences and flow estimation sequences, the flow measurement sequence including transmitting and receiving a co-propagating wave packet and a counter-propagating wave packet, determining a transit time difference between the co-propagating and the counter-propagating wave packets, determining the speed of sound in the fluid, and calcu

Abstract: The invention relates to a method of operating an ultrasonic flow meter by digitally sampling received signals. Acoustic wave packets are transmitted through a measuring distance in opposite directions, and the received signals are digitized at a sampling frequency being below the Nyquist-limit of two times the signal frequency of the wave packet to generate digitized under-sampled signals 31. From the digitized under-sampled signals, the difference in propagation time along the measuring distance is determined.

Abstract: The invention relates to a method of operating an ultrasonic flow meter by digitally sampling received signals. Acoustic wave packets are transmitted through a measuring distance in opposite directions, and the received signals are digitized at a sampling frequency being below the Nyquist-limit of two times the signal frequency of the wave packet to generate digitized under-sampled signals 31. From the digitized under-sampled signals, the difference in propagation time along the measuring distance is determined.