| 摘要 |
PROBLEM TO BE SOLVED: To provide an ultrasonic flowmeter capable of accurately measuring the flow rate. SOLUTION: The ultrasonic flowmeter comprises a measuring section 11 for measuring the flow rate of fluid to be measured that flows in a passage, based on the propagation time of an ultrasonic signal that is transmitted and received between a plurality of ultrasonic vibrators 12a, 12b placed apart a certain distance from each other on the upper stream side and the lower stream side of the passage, in which the fluid to be measured flows; a storing section 13 for determining the difference between the true value of the flow rate of the fluid measured by a master flow meter 3 and the measured value of the flow rate of the fluid measured by a measuring instrument 1 for each discrete representation point and then storing them as compensation values; an interpolation means 23 for determining continuous compensation values, by interpolating compensation values for each of the discrete representation point that are stored in the storing section, and then approximating the instrumental error curve that indicates errors of measured values ; and a compensating means 23 for determining the true value of the flow rate of the fluid by compensating the measured value of the flow rate of the fluid that is measured by the measuring section, by using the instrumental error curve that is approximated by the interpolation means. COPYRIGHT: (C)2008,JPO&INPIT
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