| 摘要 |
PURPOSE:To detect visually a frequency signal by resonance of a vibrating piece by a vortex, by placing plural vibrating pieces whose resonance frequencies are different, in the flow direction of a fluid, in the downstream side of a vortex generating body. CONSTITUTION:When a fluid flows into a duct 18, a Karman's vortex 3 having a symmetrical shape is generated alternately toward the downstream from both sides of a vortex generating body 11, and this vortex flows to the downstream. The number of generation of the vortex 3 per time is proportional to a flow speed, therefore, a vibrator 12 is forcibly vibrated by vibration number being equal to emission frequency of a vortex from the vortex generating body 11, and among vibrating pieces 12A-12N of the vibrator 12, a vibrating piece having natural vibration number which coincides with this vibration number resonates by the maximum amplitude. Therefore, a measurer is able to know a flow rate value by reading a value of a scale 16 corresponding to a position of the vibrating piece which vibrates by the maximum amplitude among the vibrating pieces 12A-12N in this way. |
