Ultrasonic Measuring Sand Trap Prototype Development

The system improves the precision of the instrument and improves its resistingcapacity to disturbance by the method of acreage ratio standard of ultrasonic which combines ultrasonic echo and attenuation .It can realize far-distance measure and control by wireless launch technique. It offers a powerful tool for the observation and prediction of rivers and water resource in our country.This system improves the recognizing ability at the dimension of the sand by using two-band frequency to collect signals. The signal accepted by ultrasonic probe passes disposing circuit, magnifying, sieving its waves, passing demodulation, sampling and holding system and then comes into A/D conversion. The CPU reads in the data, then analyzes and judges its value and phase, and then it can estimate how much sand is in the water. The ultrasonic pulse sent is controlled by CPU, The ultrasonic pulse can be sequent and discontinuous.The system offers "automatism" and "manual work" operation that can be selected by the keyboard. The "automatism" can motion automatically, gathering the data, disposing and displaying the result, then send the result to epigyny PC by COM or wirelessly; The "manual work" can be controlled by man. We can collect data, display and save result or send data from long-distance manually. It can also be handled by PC. PC sends order by dialog frame to control the instrument's work. Following the measurement's requiring, it introduces active menu, display the data and draw the wave. The system can measure the test point temperature and content of the sandiness in the water.The system is convenient, shortcut handle and low cost. It will replace the tradition apparatus for the sand measurement, lighten the worker labor, and offer important tool for our country's irrigation works build and river observation.The instrument has several shortcomings, such as the measurement range is not big enough, the precision is not high enough, and it also needs improvement. We hope the technique can be developed step by step. We hope it can meet the new demand of on the spot field-testing.