| 摘要 |
A method and an apparatus for determining the velocity, direction and other magnitudes of a flow, in particular a gas flow, in which a strongly damped acoustic signal is emitted by a first transducer in a first direction through the flow towards a second transducer producing a damped electric signal, the first deflection thereof being compared with a threshold value which is lower than the peak value of said deflection, and exceeding said threshold value being used as the end of the time measurement period started at the emission of the acoustic signal by said first transducer. In particular a single first transducer is used, and a reflecting body is placed in front of said first transducer, adapted to reflect the acoustic pulses emitted by said transducer through the flow in different directions towards one or more second transducers. |
