A magnetostrictive guided wave flaw detection system for pipeline was developed, for the non-destructive testing and long-term detection of the online pipeline. High-power sinusoidal transmitter circuit was designed, which can generate the signal from 8 kHz to 500 kHz and the transmit power is up to 2.5 kW.Gain-controllable receiver circuit was also designed, which has a sampling frequency of 2 MHz and a gain range between 20 dB and 90 dB.A PC software based on LabWindows/CVI was developed to realize functions such as parameter setting, waveform display, waveform save and so on. Experimental test using re-flection method was carried out, and results show that the system was able to detect and locate flaws whose ratio of cross sectional area loss was over 3%. And the guided wave had a slow decay rate and long distance detection ability. It is suitable for fast detec-tion and long-term monitoring of large industrial pipeline.%为实现在线管道的无损检测与长期监测,文中研制了基于磁致伸缩导波的管道缺陷检测系统.设计大功率正弦脉冲发射电路,发射频率8~500 kHz可调,瞬时功率可达2.5 kW;设计可控增益接收采集电路,采样频率2 MHz,增益范围20~90 dB;设计基于LabWindows/CVI的上位机软件,实现了参数设置、回波显示、波形保存等功能.实验结果表明,该系统对不小于3%截面损失的缺陷检测和定位效果良好,激励的导波衰减较慢,具备长距离检测的能力,适用于大型工业管线的快速检测和长期监测.
展开▼
