| 摘要 |
<p>A flow velocity measurement device for accurately measuring with the use of an ultrasonic pulse the distribution of the flow velocity of a gas flowing in a fluid piping. An ultrasonic pulse is caused to enter from a transmission transducer (11), placed on a wall of the fluid piping (10), into a target fluid (G) flowing in the fluid piping (10), and the ultrasonic pulse is detected by reception transducers (12) two-dimensionally arranged on the opposite wall in the fluid piping (10). The amount of displacement, relative to the axial direction of the piping, of the ultrasonic pulse is detected from signals received by those reception transducers among the receiving transducers (12) that are arranged in the axial direction of the piping. Two measurement lines (1, 2) having opening angles a slightly different from each other are set, and the flow velocities at predetermined positions [h<SUB>1</SUB>, h<SUB>2</SUB>] are each obtained from a difference in the amounts of displacements and in flying times detected for each measurement line (1, 2).</p> |
