| 摘要 |
PURPOSE:To provide a whistle-type flowmeter in which a linear proportionality range for the flow rate of a flowing fluid and for the oscillating frequency of a whistle sound is expanded as far as possible and which can measure a flow rate in a wide range from a low-flow-rate region up to a high-flow-rate region. CONSTITUTION:A whistle-type flowmeter is provided with a sound-generating unit 10, which is provided with a mouthpiece if into which a fluid flows, with an acoustic hole 1b through which a jet stream from the mouthpiece is passed and with a cavity by which the jeat stream gives a fluid sediment a rotating and vibrating motion, with a sound-collecting means 2 which collects a sound generated by the sound-generating unit 10, with a filter means 3 which makes the fundamental-frequency component of the generated sound by the sound- generating unit 10 out of an output-signal frequency component pass from the sound-collecting means, with a frequency detection means 5 which detects the frequency of the fundamental frequency component and with an arithmetic means 6 which operates the flow rate of the fluid on the basis of the frequency of the fundamental frequency component by means of a relational expression between a predetermined flow rate and a predetermined frequency. |
