STRUCTURAL DIAGNOSIS

Artgnomon applies structural inspection and structural diagnosis with updated modern techniques and methods allowing highly sensitive assessment of condition and accurate measurements of deformation. Techniques which can retrieve inborn and upcoming deterioration well before it becomes visible to the eye or conventional instrumentation are utilized and uniquely allow safe preventive actions to be taken well in advance.

INTERFEROMETRY

Phase information of holography interference offers a uniquely sensitive detector of high information content tracing invisible defects under the surface with unbeatable quality and clarity by any other known method. In fact the result of the holographic interference process visualizes with the fringe pattern secondary distribution the underneath activity of defects producing sets of local secondary interference fringes each one uniquely indicating the subsurface effect on the surface. Exact location, size, value of defect and shape deformation can be extracted directly by naked eye. In order to do so the generated fringes have to be isolated, identified and interpreted yet by a trained operator. The basis required to understand the fringes of holographic interferometry and assign them to underneath effects and shape deformation are given in this chapter. Automatic processes are also considered and difficulties for their implementation specifically in the field of art conservation are described.

DHSPI II

DHSPI systems operate on principles of optical holographic interferometry for wavefront recording and reconstruction combined with speckle interferometry properties and has been firstly developed at IESL-FORTH under the EC LASERACT project. Its improved version was developed under the EC project MULTIENCODE. The DHSPI II system is being currently tested in various applications in Cultural Heritage on cutting-edge EC projects as CLIMATE FOR CULTURE and CHARISMA and SYDDARTA projects.

The portable system acquires in real time the spatial displacement of surfaces and allows the structural evaluation through the interference fringe patterns formed during the wavefront recording process. Thorough post processing and analysis is required to quantify and represent graphically the surface reaction at the moment of recording. The technique can be uniquely applied in art surfaces since is nopn invasive and do not require surface preparation. Being applicable to collect data through remote computer allows displacement monitoring outside the laboratory.