Non-destructive system for in-wall moisture assessment of cultural heritage buildings

Abstract

Cultural heritage sites are exposed to several factors that cause their deterioration and degradation, namely moisture content. There are several destructive and non-destructive methods available to monitor moisture. However, destructive methods are avoided in cultural heritage to prevent surface damage, while non-destructive methods are limited to penetration capabilities. This study proposed geo-positioning of non-destructive moisture assessment based on microwave spectroscopy and close-range photogrammetry. The experimental data were collected at the Museum of King Jan III's Palace at Wilanów, Poland. The data was analysed using clustering algorithms (t-SNE, PCA, K-Means and Hierarchical), which demonstrated clear clusters. However, the microwave results did not fully align with the pin-type moisture data as the proposed microwave system was able to penetrate through the material, whereas the pin-type meter only measured the surface. Therefore, the microwave sensing approach provided more detailed moisture information of the measured material.