Design Based On Dps Technology, The Ultrasonic Doppler Flowmeter

Ultrasonic Doppler flowmeters are mainly applied to measure flux of sewage or other liquid with solid grain. They are of high resolving power, and can respond quickly with the variety of velocity. Moreover, they are insensitive to the pressure and temperature of liquid. But now, technique in this field will be improved, so the task is significative not only to automatic measurement but to environment protection.Hardware and software of ultrasonic Doppler flowmeter are designed in this paper. Digital signal processing is introduced to analyze Doppler signal, for example, FFT is used to convert Doppler signal from time domain to frequency domain, and then the algorithm of approaching peak value is put into practice. After this, filter software is in use. Thus Doppler frequency shift is obtained. According to Doppler effect, velocity and flux can be calculated. Because of mass-calculation, TMS320F240 DSP is chosen as core part in hardware design. And in hardware design, low-pass filter, amplifier, D/A convector and other circuits are included. The whole system is simple and intelligent.The system designed is improved in precision and stability. It has a distinct characteristic in display - the function of dynamic spectrum display, which is advantageous during it's installation.