Flow velocity meter having signal generating module with phase locked loop for generating continuous wave signal

摘要

A flow velocity meter is disclosed. The flow velocity meter utilizes a phase locked loop to generate an output signal and outputs the output signal to a current under test. The flow velocity meter receives a reflection signal from the current under test to calculate a speed of the current under test according to a reflection signal and a frequency difference between the output signal and the reflection signal. The flow velocity meter further includes an inclinometer for measuring a depression angle between a water level and a normal direction of the flow velocity meter and measuring a horizontal angle. The flow velocity meter can be adjusted its orientation when being installed according to the measured angles.

主权项

1. A flow velocity meter for measuring a speed of a current under test, comprising:
a signal generating module comprising:
a phase locked loop for generating a continuous wave signal with a first frequency; anda multiplier, electrically connected with the phase locked loop, for increasing frequency for the continuous wave signal to generate an output signal with a second frequency and for emitting the output signal to the current under test; a signal receiving module for receiving a reflecting signal with a third frequency from the current under test; an inclinometer for measuring a depression angle and a horizontal angle of the flow velocity meter; and a signal processing module, electrically connected to the signal receiving module and the inclinometer, for calculating the speed of the current under test according to a difference between the third and the second frequencies, the depression angle and the horizontal angle.