NDTnet 1998 Aug, Vol.3 No.8

Abstract

Fig. 3D CT reconstruction of a clear statue

During the past decade x-ray computed tomography (CT) has made a great step forward in many respects. The availability of radiation sources with reduced spot size helped to push spatial resolution to the micrometer level. New area detectors suited for x-rays result in higher speed of measurement. Novel algorithms were developed both for reconstruction and threedimensional presentation of results which allow for obtaining reliable structural information from tomographic measurement. All this has widened the scope of applications remarkably.
Cultural heritage is a field that can largely benefit from these improvements. In fact, archaeological samples need to be investigated with care and information on the inner structure of the object must be collected with high precision in order to plan and carry out a satisfactory restoration. With regard to tomographic applications, sculptures represent the most important samples to be inspected because they are generally inaccessible inside.

This work is devoted to the development of a 3D CT system for high resolution nondestructive testing DOT) of small sculptures. The object under investigation is irradiated by an x-ray cone beam produced by a microfocus tube of energy up to 200 keV; the detection system consists of a 12" Thomson image intensifier coupled with a cooled CCD camera. In this way, high spatial resolution digital radiographs can be acquired allowing real time analysis of the sample. Rotating the object over 360°, a complete set of projections is collected at different viewpoints and a fully 3D tomographic reconstruction of the object is achieved.
The final 3D image can be visualized using rendering techniques in order to get volume information. Data selection allows the inner inspection of the object and the identification of internal features providing the restorer with a straightforward tool of analysis. Small clay and bronze sculptures have been investigated in order to evaluate the performances of the tomographic system and its useful application for cultural heritage.

Abstract Source:
Book of Abstracts, 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN: 87-986898-0-00

Full-Text Source:
Proceedings of the 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN:

Publication Contact:
7th ECNDT, Park Alle 345, DK-2605 Broendby, Denmark, Fax: +45 46 26 70 11, Email: 101373.3414@compuserve.com