| 摘要 |
PURPOSE:To measure a flow velocity and a flow rate irrelevantly to whether there is a contaminant or not by providing a voltage-controlled oscillator which controls the switching speed of a switching circuit according to the output of a multiplying circuit and an arithmetic circuit which calculates the flow velocity and flow rate on the basis of the oscillation frequency of the oscillator. CONSTITUTION:The measuring device is equipped with the voltage-controlled oscillator 53 which controls the switching speed of the switching circuit 3 according to the output of the multiplying circuit and the arithmetic circuit 7 which calculates the flow velocity and flow rate on the basis of the oscillation frequency of the oscillator. Then the output signal (frequency f1) of the voltage- controlled oscillator 53 is sent to the switching circuit 3 to control its switching frequency. In this case, a clock signal is sent to a variable delay circuit 6 to set a constant quantity of delay. This device attains correlation by using a noisy signal obtained by fast switching, so the storage quality of a signal to be correlated is high and the flow velocity and flow rate are measured in a short time with high precision, thereby eliminating such a problem that the measuring operation is disabled owing to the contaminant in the fluid and its precision is influenced. |
