双频涡流检测中微弱信号的二维信息提取  

Getting planar information of weak signal in dual-frequency eddy current NDT

作　　者：冯婷婷[1] 罗飞路[1] 何赟泽[1] 

机构地区：[1]国防科学技术大学

出　　处：《中国测试技术》2008年第4期59-61,共3页CHINA MEASUREMENT & TESTING TECHNOLOGY

摘　　要：为了实现双频涡流无损检测中的有用信号提取,将正交矢量型锁相放大器应用于无损涡流检测。依据涡流检测的阻抗分析原理,利用移相技术和相关检测的算法实现了在双频涡流检测中对微弱信号的幅值、相位二维信息的提取和不同频率信号的分离。这种方法有效的抑制了噪声,实现了双频涡流检测的阻抗正交分解,实验表明,该方法稳定性和精度较好,对其他涡流检测也有借鉴作用。In order to realize getting useful signals, the orthogonal vector LIA （Lock-in Amplifier） was applied in dual-frequency eddy current NDT （non destructive testing）. According to the theory of impedance analysis, the planar information about amplitude and phase of weak signal was achieved and the separation of different frequency signals was realized in dual-frequency eddy current NDT with phase shift and cross correlation algorithm. It pressed noise effectively and got the two orthogonal vectors of impedance. The experimental results indicate that this method has good stability and precision, it also can be regarded as reference for some other eddy current NDT.

关 键 词：双频涡流 阻抗分析 相敏检波(PSD) 矢量测量 正交向量 

分 类 号：TP274.2[自动化与计算机技术—检测技术与自动化装置] TG115.28[自动化与计算机技术—控制科学与工程]