Depth-Resolved Analysis of Double-Layered Cultural Heritage Artifacts by Pulsed Thermography

Abstract

In this work, an experimental method based on the use of pulsed thermography is proposed for the depth-resolved characterization of double-layered structures of cultural heritage items. A quantitative evaluation of the inspected features was achieved by comparing thermographic data with theoretical predictions provided by specifically developed theoretical models for the analysis of the thermographic signal. In this respect, thermographic models for both optically opaque and semi-transparent materials were employed to analyze the results obtained in copper alloys and paper-based original artworks, respectively. Thermographic inspections aimed at establishing the procedure adopted for the application of insertions in ancient bronze statues are presented. Finally, the evaluation of the depth position of graphical features buried beneath leaves of historical books is proposed.