Development of a portable ESPI system for the analysis in situ of mural paintings
- E. Boaglio
- J. Lamas
- Ana J. López
- A. Ramil
- L. Pereira
- B. Prieto
- B. Silva
- Ángel F. Doval (ed. lit.)
- Cristina Trillo (ed. lit.)
- Juan Carlos López Vázquez (ed. lit.)
Editorial: SPIE, The International Society for Optics and Photonics,
ISBN: 9780819490902
Año de publicación: 2012
Tipo: Capítulo de Libro
Resumen
The use of Electronic Speckle Pattern Interferometry (ESPI) is well documented in the literature as a non-destructive technique for structural diagnostics in the field of cultural heritage.. In the case of mural paintings the lack of adhesion between the plaster and the mural support is one of the most important risk factors that threaten their conservation. With this non-invasive method it is possible to detect detachments and cracks in the paintings before they become visible The objective of this work is the development of ESPI portable equipment based on a fibre interferometer for in situ qualitative analysis of mural paintings. The novelty of the presented set up is the use of a variable ratio coupler which makes the system more immune to vibrations and allows for better use of available light compared with the equivalent of free air guided. This configuration simplifies the arrangement and makes it possible to obtain ESPI interferograms with high contrast; moreover, the use of a ceramic heater as excitation source enables the analysis during the heating. Preliminary results obtained in laboratory conditions have shown that detachments and cracks can be successfully detected on model samples of the wall paintings