STUDIES OF COPPER PATINA BY PHOTOTHERMAL BEAM DEFLECTION

Photothermal beam deflection (PBD) is a suitable method for three-dime nsional, non-contact and nondestructive surface analysis. This method has been applied to the characterization of the thermal properties of natural and artificial patina and to the measurement of the thickness of the patina layers. The thickness of the outdoor and indoor patina o f the roof of the Vienna Hofburg was measured to be about 22 mu m and 10 mu m, respectively. The thermal diffusivities of antlerite and chal canthite were determined to 0.13 cm(2)/s and 0.04 cm(2)/s, respectivel y.