基于固定频段声波共振原理的液位测量方法  

A Fluid Level Measurement Method Based on Acoustical Resonance in a Special Frequency Range

作　　者：徐晓滨[1,2] 赵晨萍[1] 夏丙铎[3] 王芝[1] 文成林[1] 

机构地区：[1]杭州电子科技大学自动化学院,浙江杭州310018 [2]清华大学自动化系,北京100084 [3]河南科技学院,河南新乡453003

出　　处：《计量学报》2011年第1期53-57,共5页Acta Metrologica Sinica

基　　金：国家自然科学基金（60934009）;浙江省自然科学基金（Y1080422）

摘　　要：已有声共振液位测量方法的量程受限于所获取的初始共振频率，这制约了此类方法在长距离测量中的应用。针对该问题，给出一种基于固定频段内共振频率的液位测量新方法。首先将检测初始共振频率变为检测较高频段内出现的一组共振频率。利用相邻共振频率的等差关系及共振频率液位换算公式得到多个测量值，将它们取平均后作为最终液位值，从而有效地降低测量不确定度。此外，提出的检测算法可以快速获取共振频率，增加了测量的实时性。最后，通过实验验证了所提方法量程更长，受液面泡沫、残渣等障碍物影响小，测量精度可达1‰优于已有声共振测量方法以及一般超声波液位仪3‰～5‰的测量精度。The range of original level measurement methods by acoustic resonance principle is limited by the fundamental resonance frequency （ RF）. It causes inability in long distance measurement. In order to overcome this limitation, a new liquid level measurement method is presented based on RFs in a special high frequency range. A set of RFs in this frequency range is detected in stead of the fundamental RF. Many measurements can be calculated by the equi - different relationships between adjacent RFs and the RF conversion formula of the level. The mean of these measurements is considered as a final value so as to reduce measuring uncertainty. In addition, the proposed detection algorithm can fast obtain RFs and improve the real - time performance. Experimental results show that new method has longer measurement range, insensitive to some foams or residues. Its measuring accuracy is up to 1‰ better than 3‰-5‰accuracies of the original methods and the common ultrasonic gauges.

关 键 词：计量学 液位测量 声共振 共振频率 快速傅里叶变换 

分 类 号：TB938.1[一般工业技术—计量学]