基于阵列探头的PFA管超声导波流量测量  

Ultrasonic guided wave flow measurement of PFA tube based on array probe

作　　者：董宇光 萧旭峯 曹丽[1] Dong Yuguang;Xiao Xufeng;Cao Li(Department of Automation,Tsinghua University,Beijing 100084,China)

机构地区：[1]清华大学自动化系,北京100084

出　　处：《仪器仪表学报》2021年第10期105-111,共7页Chinese Journal of Scientific Instrument

基　　金：日本东京计装株式会社资助

摘　　要：PFA管材耐腐蚀性好、性能稳定,被广泛应用在半导体等行业的药液运输中,为精确控制药液的用时和用量,需要研究小管径PFA管的非接触式流量测量方法。本文使用超声阵列外卡探头在PFA细管上激励超声导波,并利用导波测量流量。首先比较超声斜探头模态选择和阵列探头模态选择原理的不同,说明阵列探头的频率选择特性,进而设计阵列探头阵元宽度、厚度并制作了三种间距的阵列探头,通过频率扫描得到阵列探头的激励接收特性,比较分析了阵列探头的模态选择效果,并进行了流量测量实验。结果表明阵列探头可增强接收信号强度,提高测量灵敏度,改变阵列间距可以选择不同导波模态,在3 mm PFA管上选择L(0,5)导波模态时流速范围0~6.70 m/s内的测量结果误差限为±0.22 m/s。Perfluoroalkoxy alkane(PFA)tubes are widely used in the transportation of chemical liquids in semiconductor industry due to its good corrosion resistance and stability.In order to precisely control the dosage and time period of various liquid medicines,non-contact flow measurement of PFA tubes with small diameters is needed urgently.In this paper,ultrasonic array probe is used to excite the ultrasonic guided wave on the PFA thin tube and the flow is measured by the guided wave.Firstly,the difference of mode selection principle between ultrasonic wedge probe and array probe is compared,and the frequency selection characteristic of array probe is explained.Then,the width and thickness of array probe element are designed,and three kinds of array probe with different element spacing are prepared.The exciting and receiving characteristics of the array probe are obtained through frequency scanning.The performance of mode selection of the array probe is compared and analyzed,and the flow measurement experiment is carried out.Results show that the array probe can enhance the received signal's magnitude and improve the measurement sensitivity.Different guided wave modes can be selected by changing the array spacing.When the L(0,5)guided wave mode is selected on the 3 mm PFA tube,the error limit of the measurement results in the flow rate range of 0~6.70 m/s is±0.22 m/s.

关 键 词：PFA管流量测量 阵列探头 超声导波激励 模态选择 

分 类 号：TH814[机械工程—仪器科学与技术]