Pulsed eddy current is an emerging technique for measuring wall thinning of steel under insulation. Ideally, it would be desirable to obtain the most localised information of pipe condition possible. The localization of information is constrained by the flow of eddy currents in the pipe. This in turn is heavily influenced by the orientation of the probe. This paper examines three different probe orientations, representative of all probe types for their influence on eddy current flow. All three orientations will have difficulty accurately measuring highly localized thinning, because the eddy currents that give rise to their signal spread out rapidly way from the thin region in the long time signal decay. Of the three orientations, the longitudinal one does the best job of localizing the eddy currents directly under the probe.

中文翻译：

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影响管道脉冲涡流检测空间分辨率的因素

脉冲涡流是一种新兴技术，用于测量绝缘下钢的壁厚。理想情况下，希望尽可能获得管道状况的最局部信息。信息的定位受到管道中涡流流动的限制。这反过来又受到探头方向的严重影响。本文研究了三种不同的探头方向，代表所有探头类型对涡流的影响。所有三个方向都难以准确测量高度局部化的变薄，因为在长时间的信号衰减中，产生其信号的涡流会从薄区域迅速扩散。在三个方向中，纵向方向在定位探头正下方的涡流方面做得最好。