一种大量程超声波液位计的实现

摘要

To solve the existing problem that the range of ultrasonic level gauge is narrow and the error is relatively big in remote measurement,a realizing method for wide range ultrasonic level gauge is proposed.On the basis of no changing the transmission power and receiving gain,improve the dissemination efficiency of the ultrasonic in the air through acoustic impedance transformation,and increase the distance liquid surface reflection echo signal-to-noise ratio using matching filter.Through simulation and practical test,the method can effect significantly,and able to improve the maximum range of a ultrasonic sensor whose frequency is 40 kHz from 5 m to 15 m,and still able to identify the echo signal of liquid surface reflection.It provides a new method for long distance ultrasonic liquid level measurement.%为解决现有的超声波液位计测量量程小,在远距离测量时误差较大的问题,提出一种大量程超声波液位计的实现方法。在不改变超声波发射功率和接收增益的基础上,通过声阻抗变换的方法提高超声波在空气介质中的传播效率,以及利用匹配滤波提高远距离液面反射回波的信噪比。经过仿真及实际测试,此种方法效果显著,能将一种频率为40 kHz超声传感器的最大量程从5 m的提高至15 m,并仍可以较好的识别出液面反射回波信号。为远距离超声波液位测量提供了一种新方法。