Abstract
One of the most important aspects in laser cleaning of artworks is the possibility for on-line monitoring the cleaning process. This ensures that the cleaning intervention is satisfactory without any damage to the underlying original surface. In this work it is shown that following and observing the integrated densities of the plumes generated during laser cleaning may be a simple, safe and straightforward methodology to monitor the removal process. A series of experiments on reference marble with simulated thick encrustation were considered to evaluate the plume monitoring technique. Parameters influencing the cleaning process and ablation threshold of the black crust (such as laser fluence, number of pulses etc.) were considered while the results were also evaluated under the microscope. The results of this study will be presented and discussed with the aim to establish accurate and reliable monitoring tools to follow the laser cleaning process.