| 摘要 |
PROBLEM TO BE SOLVED: To provide a flow velocity measurement technology hardly influenced even it the case that sound velocity is changed in a fixed direction due to change in a measuring environment or the like in one direction. SOLUTION: In this flow velocity measuring method, ultrasonic wave is propagated in the forward direction along the propagation direction of sound, and is propagated in the reverse direction reverse to the propagation direction of the sound at the same time, and the flow velocity is obtained from a forward propagation time required for propagating the ultrasonic wave between the echo sounder transducers in the forward direction and a reverse propagation time required for propagating the ultrasonic wave between echo sounder transducers in the reverse direction. A first process where the reverse propagation time is obtained after obtaining the forward propagation time, and a second process where the forward propagation time is obtained after obtaining the reverse propagation time are carried out, and then the flow velocity is obtained based on the results obtained from both of the process. |
