Quantification and Automation of Pulsed Thermographic NDE

摘要

Until recently, thermographic methods for NDE have generally been quantitative, relying heavily on operator interpretation of image data. Although quantitative methods have been developed, they have generally required a priori knowledge of the sample physical properties, or identification of a defect free region within the field of view. Recent advances in pulsed thermography allow reference-free measurement of defect size, sample thickness and material properties without operator intervention or a priori knowledge of sample properties. An essential component of these advances are new signal processing methods based! on both the spatial and temporal thermal response of the sample surface temperature to an instantaneous heat pulse. These methods provide a significant reduction in noise and blurring due to lateral diffusion of heat, and effectively increase the maximum penetration depth and spatial resolution beyond that of conventional thermography.