| 摘要 |
PURPOSE:To obtain the device having an excellent S/N ratio and vibration resisting property, with regard to the measurement of the flow speed and the flow rate of fluid by utilizing K arm an vortex, by arranging two piezoelectric sensors in a concave part with a specified interval being provided, converting each sensor output and then performing computation, thereby effectively removing the effect of the noise due to the disturbing vibration. CONSTITUTION:When the fluid to be measured flows in a pipe, a vortex generating body 13 generates the K arm an vortex and receives a lift change. Bending moment MV is acted on a sensor part 14, and approximately linear stress distribution is generated. The vortex generating body 13 receives the force whose direction is the same as the lift of the vortex by the disturbing vibration excited by a pump and the like. The bending moment is acted on the sensor 14 in respective modes. As a result, in the charges q1 and q2 detected by the piezoelectric sensors 14a and 14b, the noise charge due to the vibration and the strain in the pipe is superimposed on the signal charge caused by the life of the vortex. When the piezoelectric sensors 14a and 14b of the sensor part 14 are arranged at two points (P and Q) where the noise charge due to the vibration of the vortex generating body 13 becomes zero, the effect of the noise due to the disturbing vibration can be effectively removed.
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