| 摘要 |
The invention relates to a method for determining characteristics of the flow of a medium in a channel by measuring the transit time of sound waves which are transmitted between one or more transducers, and determining the characteristics from the measured transit times. In one embodiment of the method according to the invention, at least two sound waves whose transit time depends on swirl are transmitted along acoustic paths with a different sensitivity to swirl, and a measure of the swirl is determined from the measured transit times. In another embodiment, at least two sound waves whose transit time depends on the symmetry of the flow profile are transmitted along acoustic paths with a different sensitivity to symmetry, and a measure of the symmetry is determined from the measured transit times. These embodiments are preferably combined. If weighting factors are allocated to the values obtained, the individual velocities of the sound waves can be used to calculate the average flow velocity and/or the throughput of the medium. Since allowance is made for possible disturbances of the velocity profile, the accuracy of the calculated variables is good. The invention also provides for a device, by means of which the method according to the invention can be carried out. <IMAGE> |
