Thermography for non-invasive diagnosis of conservation state of archaeological discoveries

The present paper discusses about the use of active thermography to assess the conservation state of archaeological discoveries and historic sites. The preservation of historical and archaeological heritage is today an open issue due to the amount of sites and to the costs of the current methodologies and technologies used. As a consequence, interventions are made only when a deterioration process is in progress. The use of non-invasive techniques is essential for such kind of applications in order to not compromise the integrity of the find. Thermography is a contactless measurement technique able to monitor thermal response of any object even during dynamical conditions. Its basic principle allows to evaluate the presence of humidity, cracks, variation of thickness, structural integrity, exposition to heat sources, previous restoration works not visible at naked eye. Therefore, this technique can be used to evaluate the integrity of buildings, statues, paintings, artifacts, etc The paper aims to describe how this technique is used to diagnose, monitor and preserve the conservation state of archaeological discoveries, sites and ruins. The considered application case concerns the Riace Bronzes, two bronze statues of the first half of the V century B.C. preserved in the National Museum of Magna Græcia, Reggio Calabria, Italy.