Active infrared (IR) thermography, because of its high productivity and illustrativeness, is a promising technique in nondestructive testing (NDT). The purpose of this paper is to discuss a concept and practical implementation of a portable experimental unit intended for IR thermographic NDT of corrosion in metallic shells.,The basic theory relates to the analysis of heat conduction in a plate with rear-surface material loss subjected to pulse, thermal wave or arbitrary heating.,The amplitude of temperature anomalies over defects and their characteristic observation times depend on material loss, size and shape of corrosion defects. A flexible architecture of the inspection unit is proposed to include flash tubes, halogen lamps and laser-emitting diode (LED) panels as sources of stimulating thermal radiation. In particular, LED heaters might be perspective due to their narrow spectral band, which is beyond a spectral sensitivity of modern IR imagers. It has been found that the IR thermographic technique is convenient for detecting material loss of up to 15–20 per cent in uniformly painted steel shells with thickness up to 8 mm. The concept of signal-to-noise ratio has been applied to evaluate efficiency of data processing techniques, such as Fourier transform and principal component analysis.,The developed equipment and inspection guidelines can be used for detecting hidden corrosion in metallic objects, such as above-ground tanks, pipes, containers, etc.

中文翻译：

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隐性腐蚀红外热像仪

主动红外 (IR) 热成像由于其高生产率和说明性，在无损检测 (NDT) 中是一种很有前途的技术。本文的目的是讨论用于金属壳腐蚀的红外热成像无损检测的便携式实验装置的概念和实际实施。基本理论涉及分析具有背面材料损失的板中的热传导。脉冲、热波或任意加热。缺陷上的温度异常幅度及其特征观察时间取决于材料损失、腐蚀缺陷的大小和形状。提议的检查单元的灵活架构包括闪光灯管、卤素灯和激光发射二极管 (LED) 面板作为刺激热辐射源。特别是，LED 加热器可能是透视的，因为它们的光谱带很窄，超出了现代红外成像仪的光谱灵敏度。已经发现，红外热成像技术可以方便地检测厚度高达 8 毫米的均匀涂漆钢壳中高达 15-20% 的材料损失。信噪比的概念已被应用于评估数据处理技术的效率，例如傅里叶变换和主成分分析。开发的设备和检查指南可用于检测金属物体中的隐藏腐蚀，例如上述- 地面储罐、管道、容器等。已经发现，红外热成像技术可以方便地检测厚度高达 8 毫米的均匀涂漆钢壳中高达 15-20% 的材料损失。信噪比的概念已被应用于评估数据处理技术的效率，例如傅里叶变换和主成分分析。开发的设备和检查指南可用于检测金属物体中的隐藏腐蚀，例如上述- 地面储罐、管道、容器等。已经发现，红外热成像技术可以方便地检测厚度高达 8 毫米的均匀涂漆钢壳中高达 15-20% 的材料损失。信噪比的概念已被应用于评估数据处理技术的效率，例如傅里叶变换和主成分分析。开发的设备和检查指南可用于检测金属物体中的隐藏腐蚀，例如上述- 地面储罐、管道、容器等。