关键词: 超声波流量测量, 时间差, 相关法, 高精度

Abstract:

In some specific circumstances,it is inconvenient to install probes in the pipe wall.In view of this,this paper presents an ultrasonic flow measurement method and corresponding device that puts the probe in the pipe and parallel to the direction of flow.When calculating the time difference,we use the method of correlation algorithm to calculate the time difference.The method of correlation algorithm itself has some characteristics such as filtering and denoising to improve the accuracy of the time difference.The hardware system consists of ultrasonic transmitting,receiving and amplifying circuits,using the high speed A / D converter for digitizing the received signal.The experimental results show that the circuit emitting circuit can produces impulse with high amplitude and narrow width.This circuit can effectively stimulate the ultrasonic transducer.The error between the actual value and the calculation value after waveform treatment of correlation algorithm is very small.The improved accuracy of the time difference facilities the flow calculation better.

Key words: ultrasonic flow measurement;time difference;correlation algorithm;high-precision