| 摘要 |
PROBLEM TO BE SOLVED: To prevent the influence of the reverberation of ultrasonic waves by putting an ultrasonic flowmeter that takes the place of a large-capacity film-type gas meter into practical applications quickly to obtain a total flow rate instantly. SOLUTION: Fluid shunts first, second, and third measurement channel parts 1, 2, and 3 with an equal channel sectional area and flows to the right. A sound wave is discharged from a transducer 1A of the channel part 1 and is received by a transducer 1B. Simultaneously, a sound wave is discharged from a transducer 2A of the channel part 2 and is received by a transducer 2B. Simultaneously, a sound wave is discharged from a transducer 3A of a channel part 3 and is received by a transducer 3B. Forward total propagation time T1 from the discharge by the transducer 1A to the reception by the transducer 3B is obtained. Then, a sound wave is transmitted and received continuously and successively as shown is figure (c) also for a backward direction to obtain total propagation time T2. An average flow velocity is calculated from T1 and T2 and further a flow rate is calculated.
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