Study of the accuracy of transit time ultrasonic flow measurement for liquids

High-precision measurement of liquid flow using transit time method requires accurate measurements of the absolute propagation time and the relative propagation time. The reference signal for the measurement of the absolute propagation time in ultrasonic flow measurement is rather difficult to get. Aiming at this problem, an extraction method of the reference signal is presented. The boundary conditions for energy and phase are set to ensure the accuracy of the extracted reference signal, which can adaptively adjust the fundamental signals according to the actual velocity distribution interval. The sampling rate and peak detector factors that influence the precision of the relative time difference are further studied with simulation analysis; An experimental system is designed and the proposed method and the simulation analysis are verified on a hydraulic platform. The results prove the effectiveness of the method and the correctness of the simulation analysis.