| Both industrial production and scientific experimentation cannot go away with realization and control of flow. The ultrasonic flow measurement technology's operating theory is that when ultrasonic pass the liquid, it carries out the signal reflecting the liquid's flow velocity, and then, the signal will be used to compute the flow. Due to its advantage in accuracy, turndown ratio and no excess pressure drop, the current market for ultrasonic flow meter technology is growing rapidly in flow measurement. However, the ultrasonic flow meter develops just some ten years, and has not run in all fields it can be, so it provides many distinct and difficult challenges, and its significance not only to automatic measurement but to environment protection.The paper introduces basic principle and realizing method of the ultrasonic flow measurement technology. On basis of absorbing and referring to the domestic and foreign advanced ultrasonic flow measurement technology, the system hardware is designed and the idea of the system software is given. The core of the hardware is chip of TMS320LF2407A. High precision is guaranteed because of quick velocity of signal processing of DSP chip. Hardware includes generating and amplifying of ultrasonic, receiving and amplification of signal, data acquisition, Memory, display and DSP; on the base of hardware, Digital signal processing is introduced to analyze Doppler signal, for example, FFT is used to convert Doppler signal from time domain to frequency domain. After this, filter software is in use. Thus Doppler frequency shift is obtained. According to Doppler Effect, velocity and flux can be calculated.The system can transmits and receives the ultrasonic wave, the results of practical measurement and experiment show that the scheme has reached the requisition. Because of the restriction of experiment, the practice precision of the measure has not been measured.
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