ABSTRACT
Recent studies have shown the great potential of active thermography for non-destructive inspection of modern materials and applications (Busse et al. 2001, Avdelidis et al. 2005). The main advantage of using active thermography is the rapid non-intrusive testing of large areas, especially when compared to other commonly used methods, e.g. ultrasonic testing, where a time consuming process of tracing the contours is required. Thermal waves are generated by energy deposited on the sample surface. The evolution of these waves into the cooler interior is influenced by material properties (density, heat capacity, thermal conductivity) and internal defects (delaminations, porosity, foreign materials), and these in turn influence the surface temperature. An infrared sensor (IR camera) can be used to measure the surface temperature of a definite area depending on the detector size and the distance between sensor and sample. From the temperature history, material properties as well as flaw characteristics can be derived (Maldague & Marinetti 1996, Busse 1992, Ringermacher et al. 2002, Zauner et al. 2006).
