Novel method of sound speed measurement based on parameter-estimation of continuous wave

The speed of sound can provide very useful and accurate information about the fluid thermodynamic quantities, and therefore the measurement of sound speed in the fluid with high accuracy has very important significance in the field of fluid measuring and controlling. The precise measurement of sound speed for fluid using continuous wave signal processing technique is discussed in the paper, which has strong anti-interference capability, rapid response and high precision. Through this technique, continuous wave signal used in measurement was generated through DDS technique and sampled by the ADC and processed by digital signal processor then the sound propagation time and speed value was estimated. By sound speed measurement experiment in distilled water, the favorable results proved that the measurement precision is better than 10-5 and 20 measurements per second can be achieved. This technique can be used for a variety applications which need precise and rapid measurement of sound speed.