| 摘要 |
PURPOSE:To obtain a flowmeter which is excellent in accuracy, resposiveness and durability, by providing a microwave Doppler radar on the solid transportation pipe whose medium is gas, and deriving a flow rate in accordance with the mean frequency and amplitude of a Doppler signal. CONSTITUTION:A microwave Doppler radar 1 consisting of a Gunn diode oscillator 11, a circulator 12 and a microwave detector 13, and a signal processing part 4 are installed to the transportation pipe P through the connecting waveguide 2 and the coupler 3. In this constitution, a microwave of the oscillator 11 is projected into the transportation pipe P through the coupler 3, etc., it is scattered by a pulverulent body in the pipe, the rear scattered wave is returned again to the detector 13, is compounded with leakage of the circulator, and becomes a Doppler signal. This signal is multiplied by the reflection power corresponding to the mean frequency and amplitude of the Doppler signal, and a flow rate of the pulverulent body is calculated. In this way, a flowmeter which is high in accuracy, responsiveness and durability can be obtained. |
