Method of, and apparatus for, measuring the velocity of a fluid

摘要

An apparatus for measuring the velocity of fluid flowing in a fluid path, includes a signal generator for generating input signals, and two ultrasonic transducers coupled diagonally across the fluid path. The transducers are connected in series to the signal generator such that equal and opposite input signals are simultaneously applied to each transducer. A signal processor combines the output signals of each transducer caused by the ultrasonic signal transmitted by the other transducer across the fluid path to obtain a destructive interference signal and a constructive interference signal, and compares the amplitude of the destructive interference signal with the amplitude of the constructive interference signal to obtain a measure of the velocity of the fluid. The signal processor may also compare the phase of the destructive interference signal with the phase of the constructive interference signal to obtain a measure of the direction of flow. The method measuring the velocity of a fluid according to this method comprises simultaneously applying equal but opposite input signals to two ultrasonic transducers coupled diagonally across the fluid path to cause them to generate ultrasonic signals. The output signals of each transducer caused by the ultrasonic signal transmitted by the other transducer across the fluid path are combined to obtain a destructive interference signal. The amplitude of the destructive interference signal is compared with the amplitude of the constructive interference signal to obtain a measure of the velocity of the fluid.