| A sound velocimeter system on bubbly water is designed in this paper.Based on ARM embeded System and RTOSμC/OS- II, three parts, i.e.,the transmitter, receiving set, transmitting transducer and hydrophone are included in the system.Based on classical theories on bubbles,and refered to bubbles' insertion loss and related results of experiment on bubble-shell in the lake ,the propagation characteristics are analyzed in the paper. To increase the dynamic range of the receiving set and lower the influence of acoustic attenuation and insertion loss caused by the bubbles, clamper and nonlinear logarithmic amplifier is designed;to improve Signal-to-Noise, a very low noise continuous time Butterworth bandpass filter made up of LTC1562 is designed in the receiving set. According to the impedance characteristic of transmitting transducer, a signal generator and transformer coupled class D power amplifier are designed. And a LCD Liquid Crystal Display module and its driver is also developed. The transplantion ofμC/OS- II on LPC2210 is described detailedly ,the main programme based on it is also given.Some performance parameters of the sound velocimeter system are given, error analysis and pool measurement are carried out in the end.
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