Eddy current pulsed thermography (ECPT) as one of the emerging nondestructive testing and evaluation (NDT&E) techniques has been used for the evaluation of the integrity of rail tracks, especially for rolling contact fatigue (RCF) detection and crack sizing. This paper proposes a probability of detection (POD) analysis framework for the ECPT system. Specifically, three different features, i.e., max thermal response, first-order differential imaging, and ratio mapping of the first-order differential imaging, were used to quantify the length of the angular slot by linear fitting. Based on the fitting relation between these features and the slot length, POD curves for linear-coil-based ECPT system of angular defect detection were calculated and compared. Results show that the max thermal response feature has the highest repeatability and detectability for shorter slot detection. First-order differential imaging and ratio mapping features are more convincing for longer slot detection.

中文翻译：

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角缺陷定量涡流脉冲热成像的检测概率


涡流脉冲热成像 (ECPT) 作为新兴的无损检测和评估 (NDT&E) 技术之一，已用于评估铁轨的完整性，特别是滚动接触疲劳 (RCF) 检测和裂纹尺寸测量。本文提出了 ECPT 系统的检测概率（POD）分析框架。具体来说，使用最大热响应、一阶微分成像和一阶微分成像比率映射这三个不同特征，通过线性拟合来量化角槽的长度。基于这些特征与槽长的拟合关系，计算并比较了基于线性线圈的ECPT角缺陷检测系统的POD曲线。结果表明，最大热响应特征对于较短的槽检测具有最高的重复性和可检测性。一阶微分成像和比率映射功能对于较长的槽检测更有说服力。