| 摘要 |
PROBLEM TO BE SOLVED: To provide an ultrasonic flowmeter capable of accurately measuring a flow rate of a fluid.SOLUTION: An ultrasonic flowmeter comprises: a first ultrasonic transducer 101 for making a first ultrasonic signal incident on a pipe 10 through which a fluid flows; a second ultrasonic transducer 102 which is arranged at a position where the first ultrasonic signal can be received, and is for making a second ultrasonic signal incident on the pipe 10; a flow velocity calculation part 302 for calculating a flow velocity of the fluid in the pipe 10 based on a first time until the first ultrasonic signal arrives at the second ultrasonic transducer 102, and a second time until the second ultrasonic signal arrives at the first ultrasonic transducer 101; a part 351 for storing a correction function using a logarithm that stores a correction function using a logarithm approximating, by polygonal lines, a relationship between a logarithm of a Reynolds number and a correction coefficient of the flow velocity; and a correction part 303 using a logarithm that corrects the flow velocity using the correction coefficient corresponding to the Reynolds number of the fluid.SELECTED DRAWING: Figure 1 |
