Journal of Thermal Analysis and Calorimetry, Vol. 66 (2001) 307–314 NON-INVASIVE ANALYSIS OF ARTISTIC HERITAGE AND ARCHAEOLOGICAL FINDINGS BY TIME RESOLVED IR THERMOGRAPHY F. Scudieri, F. Mercuri and R. Volterri Department of Mechanical Engineering and INFM section, University of Rome ‘Tor Vergata’, Via di Tor Vergata 110, 00133 Rome, Italy Abstract The structure and the preservation state of artistic heritage and archaeological findings have been studied by the analysis of the heat diffusion process in the sample. The investigations have been per- formed by non-invasive time resolved infrared thermography (IRT). Thickness maps, buried defects detection, inhomogeneity and corrosion analysis, as well as the quality check of welding and rein- forcements elements, have been performed on the studied samples. Keywords: cultural heritage, infrared thermography Introduction Mainly due to its non-invasive (non-destructive, non-contact) nature, infrared thermo- graphy (IRT) has been recently widely used to investigate artistic heritage and archaeo- logical findings. Thermography provides a temperature (T) monitoring of different sam- ple surface areas and makes possible to perform a time resolved analysis of the heat diffusion process in the sample, providing information on its subsurface structure (for in- stance [1, 2] and references therein). The results reported in the present paper have been obtained by a particular photothermal IR thermographic configuration (flash pulse method). In the used con- figuration, a thermal perturbation is generated at the sample surface by absorption of the light produced by two or more flash lamps. That gives rise to a fast (few millisec- onds) temperature rise at the lighted surface, followed by a decay of the temperature value which depends on the heat diffusion process inside the sample. Deviations from the expected T vs. time (t) behaviour reveals a local variation of the thermal proper- ties which can be connected to the presence of inhomogeneities, corroded parts, de- fects (disbonding, delaminations, voids) or any thermal barrier. Results will be also presented showing how IRT enabled us to detect the position, and check the quality, of welding and reinforcement elements sited under the observed sample surface. Finally it is worthwhile to note that, for homogeneous material, when the ther- mal diffusivity D is known, thermography provides, by the analysis of the surface 1418–2874/2001/ $ 5.00 © 2001 Akadémiai Kiadó, Budapest Akadémiai Kiadó, Budapest Kluwer Academic Publishers, Dordrecht