Figure 6Examples of thermal images in presence of buried structures.3.2.2. Application to the Cultural Heritage Olaparib structure The increasing sensitivity towards the conservation of cultural properties is looking at infrared thermography as an excellent aid . The main causes of degradation of art treasures lie in exposure to adverse environmental conditions including thermal and mechanical stresses and variation of humidity which give rise to microcracks, disbonding, and formation of mould. It is of utmost importance to detect defects at an incipient stage and to understand modifications induced by variation of environmental parameters to plan the most adequate program of prevention from decay of artworks.
Infrared thermography has proved its capability to help find detached tiles in mosaics and degradation of plaster and frescoes , to measure thermal properties like diffusivity and effusivity of materials for the solution of the inverse problem , and to monitor microclimatic conditions  which often represent the major hazard issue for the conservation of precious works of art.Herein, some phase images collected during campaigns of tests in situ in the Archaeological Museum of Naples and in the archaeological site of Pompeii are shown. Such images are taken with cooled detector cameras (Agema 900 and SC3000) equipped with the IR lock-in option. In particular, phase images reported in Figure 7 are taken with the Agema 900 camera, while phase images reported in Figure 8 are taken with the SC3000 camera.Figure 7A part of the Battle of Issus mosaic (Archaeological Museum in Naples).
Figure 8Phase images ((b)�C(d)) on the wall (a) in the oecus room in Villa Imperiale (Pompeii).Figure 7 shows a picture of a portion of the famous mosaic of the Battle of Issus (Archaeological Museum in Naples) with two phase images. This is a masterpiece of inestimable value, which was created with the opus vermiculatum technique; tiles of miniature size (about 20 tiles in a cm2) were glued with rosin, which is sensitive to temperature rise. Then, the inspection of such artwork Dacomitinib poses serious problems in terms of its safeguard. As a general comment, the PT technique is not suitable since it is affected by nonuniform emissivity distribution which is a major problem in the evaluation of mosaics, because, to obtain the desired chromatic effects, tiles of different materials, colours, and brightness are generally used and this causes local variation of emissivity. Thus, the evaluation is made with the LT technique and with special care to avoid undesired temperature rise; the lamp is positioned far enough from the mosaic surface.