| 摘要 |
PROBLEM TO BE SOLVED: To accurately carry out measurement even if the velocity vector of fluid in a channel is inclined in regard to a channel axis by arranging a plurality of ultrasonic sensors while measurement lines being used as an ultrasonic radiation center line cross in the channel. SOLUTION: A pulse-Doppler-type ultrasonic current meter is equipped with ultrasonic sensors 1 and 2 with a frequency of 100 kHz-1 MHz, for example, on the outer wall of a channel. An ultrasonic wave is radiated into the channel from the sensor 1 at an angleθ1 to a wall surface, and a measurement line 6 is formed. The sensor 2 is installed, for example, in a symmetrical position, and a measurement line 7 is formed at an angleθ2 to the wall surface. The measurement lines 6 and 7 cross each other near a channel center line 4. Then, a reflection wave from a scattering particle 5 with a velocity vector C being inclined by an angleαfor the center line 4 near a channel center returns to each of the sensors 1 and 2, velocity constituent C1 and C2 in the direction of each measurement line are measured, velocity Cm in an axial direction or the like is calculated by a specific method. The measurement line of the sensor 2 may be vertical to the wall surface. |
