Noninvasive Measurement of Moisture Content in Stone Materials.

In this work, the dielectric characterization of pietra gentile (a kind of stone typically found in Cultural Heritage structures in Southern Italy) was carried out. Measurements were performed for increasing level of water content of the pietra; thus identifying, empirically, the relation between moisture content and dielectric permittivity. The obtained laboratory results can be used to derive moisture content/dielectric permittivity calibration curves that could be used, in practice, for noninvasive on-the-field moisture monitoring of pietra gentile-made Cultural Heritage structures. For example, it would be possible to use the obtained calibration curves with non-invasive measurement systems, such as time domain reflectometry in conjunction with antennas, coaxial probes, or waveguides apertures.