OptoSurf® Measurement Technology for Use on Surfaces of Historic Buildings and Monuments Cleaned by Laser

Abstract

A documentation and analysing instrument with the name OptoTop ® was developed in order to measure the quality of laser cleaning on site and to document the individual stages of virgin surface area, reference area and the cleaned area on the building. The instrument comprises a fully automated optical documentation unit, which is portable and can be used without external power supply. Several high precision images of the area of interest are taken during the automated routine. A special newly developed software calculates first the 3D topography and also specific structure and macro- and micro-roughness parameters. As documentation for the visual impression of the human eye, an additional direct image of the area is taken and also analysed. This new instrument was applied in Austria, Spain, Ireland and Germany at several sites by several organisations and restoration companies. The results are shown and analysed. The benefits and limitations of this technology are demonstrated and discussed.