提出了凝汽器传热管管板区Bobbin技术检测的盲区问题, 分析了盲区的成因, 并设计模拟管板开展了试验研究。结果表明, 管板结构信号对Bobbin探头检测能力影响较大, 在距离TTS 8 mm范围内形成检测盲区; 而且, 越靠近胀管末端, 其影响越大。最后, 提出了用CXB技术解决Bobbin检测技术管板盲区问题的设想。

This paper firstly shows the problem of blind area encountered in eddy current testing of heat exchanger tubes of condenser near the tube sheet area with bobbin technique. In addition, it gives the principle of blind area and experimental results with mockup tube sheet. The experiments indicate that signals of the tube sheet and expanded area have great impact on inspection ability of bobbin probes. As a result, an 8 mm length blind area outside the TTS comes. And the less the distance from TTS is, the more the influence from TTS. Finally, a CXB technique is figured out as a method to solve blind area problem.