| 摘要 |
PURPOSE:To make it possible to perform accurate measurement of the flow rate in a pipe during the operation, by obtaining the oscillating frequencies of VCOs during the propagations of ultrasonic waves in the forward and reverse directions. CONSTITUTION:Specified switches are operated by control signals 101, 103, and 105 from a control part 95. The oscillating frequency of the VCO13 has specified relationship with respect to the propagating time of the ultrasonic wave 45 in the forward direction. The frequency of the VCO15 has specified relationship with respect to the propagating time of the ultrasonic wave 47 in the reverse direction. Each oscillated frequency is counted and stored in an operating part 91. Then each switch is changed by each control signal again, and each oscillating frequency of the VCOs 13 and 15 is counted and stored. Then a specified computation is performed for each shorted value, and the flow rate of fluid to be measured 75 is obtained. |
