Patent ID: 7845240

Claim:
Device for determining a flow characteristic of a fluid in a conduit, comprising: a conduit body, a first pair of first ultrasonic transducers aligned along a first line at the wall of the conduit body and defining a first swirl sensitive acoustic path and a second pair of second ultrasonic transducers aligned along a second line at the wall of the conduit body and defining a second swirl sensitive acoustic path, the first and second lines being parallel to the conduit body axis and at the same side of the conduit body, the first and second swirl paths having a clockwise and a counter clockwise orientation respectively as viewed in axial direction, a third pair of third ultrasonic transducers and a fourth pair of fourth ultrasonic transducers the transducers of the third pair being positioned diametrically opposite to each other at the wall of the conduit body and spaced apart in the axial direction such that the third transducers define a third acoustic path having a single reflection against the inner wall of the conduit body and the transducers of the fourth pair being positioned diametrically opposite to each other at the wall of the conduit body and spaced apart in the axial direction such that the fourth transducers define a fourth acoustic path, the fourth acoustic path being symmetrical to the third acoustic path, the transducers of each pair being arranged spaced apart in the axial direction of the conduit body, 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.