Patent ID: 8146442

Claim:
Device for determining a flow characteristic of a fluid in a conduit, comprising: a conduit body, a first pair of ultrasonic transducers defining a first swirl sensitive acoustic path, a second pair of ultrasonic transducers defining a second swirl sensitive acoustic path, the ultrasonic transducers of the first pair and the second pair being positioned along a first line and a second line at the wall of the conduit body, the first and second lines being parallel to the conduit axis and at the same side of the conduit body, the first and second swirl sensitive paths having a clockwise and a counter clockwise orientation respectively as seen in axial direction, a third pair of ultrasonic transducers defining a third swirl sensitive acoustic path, a fourth pair of ultrasonic transducers defining a fourth swirl sensitive acoustic path, the ultrasonic transducers of the third pair and the fourth pair being positioned along a third line and a fourth line at the wall of the conduit body parallel to the conduit axis, the third and fourth swirl sensitive paths having a clockwise and a counter clockwise orientation respectively as seen in axial direction, the third and fourth lines being at the same side of the conduit body and tangentially staggered with respect to the first and second lines, the transducers of each pair being arranged spaced apart in the axial direction of the conduit body and the acoustic paths extending in the axial direction of the conduit body, wherein the transducers are capable of acting individually as a transmitter and receiver for transmitting ultrasonic waves along their respective acoustic paths and receiving thereof, and means for measuring the transit times of transmitted ultrasonic waves and for determining a flow characteristic from the measured transit times.