An improved noninvasive resonance method for water content characterization of Cultural Heritage stone materials

Measurements are performed for five levels of water content of the stone samples, and the empirical relationship between each considered water content level and the corresponding resonance frequency of the patch resonator are derived. To enhance the contact between the planar resonator and the rough surface of the stone, the patch is covered with a thin layer of soft silicon conductor. The obtained results demonstrate the robustness of the presented solution.