| 摘要 |
PROBLEM TO BE SOLVED: To provide an ultrasonic flow meter capable of estimating the pattern of flow rate distribution state and computing the flow rate of an measured fluid based on the pattern of flow velocity distribution even when the flow velocity distribution changes in a flow rate region without intersecting partition members and the like inside of a channel. SOLUTION: An ultrasonic flow meter includes a flow velocity computing part 13 for computing flow rate of a measured fluid based on the propagation time of ultrasonic wave which is transmitted and received by a pair of ultrasonic elements 10, 20. A pair of the ultrasonic elements 10, 20 divide the channel width into two kinds of detection areas with a first ultrasonic pattern which is irradiated from a pair of the ultrasonic elements 10, 20 and having narrower directivity width than that the channel width and a second ultrasonic pattern which reflects and diffuses at the irradiation face of the ultrasonic element of another side and having different directivity from that of the first ultrasonic pattern. A flow rate measuring part 13 estimates the flow velocity distribution of the measured fluid based on the propagation time of the first ultrasonic pattern and the second ultrasonic pattern to compute the flow rate from the estimated flow velocity distribution. COPYRIGHT: (C)2009,JPO&INPIT
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