Defect localization in museum items with traditional and electronic holographic nondestructive testing

In this paper some experimental results are presented, related to practical applications of holographic nondestructive technique for inspection of museum items condition, especially in detection of deformation, stress analysis, and defects localization. These results are obtained using the basic principles of traditional double-exposure holographic interferometry as well as electronic speckle pattern interferometry with computer image processing. In the latter case the accuracy in displacement measurements was studied on a test-object. Several museum items have been selected for their condition inspection: a 19th century oil painting, an 18th century icon on wooden panel, and an enameled terra-cotta vase of the 17th century. The described technique can give quite accurate meteorological information, and is also rather promising for rapid qualitative analysis of the object condition before and after restoration, as well as during its storage.