Description: The sample is placed into a cylindrical volume, where it is wetted axially from one end using water that has specific salts in it. Several X-ray tomographic images of the sample are taken during the wetting process. The gray-value profile in the wetting direction is recorded. The salty water is visible as increased gray level. The wetting process is first done wit NaCl + CaCl2 water solution until saturation is reached, and then continued with marker salt specified below. After wetting, the salt content profile is measured with micro-XRF from the surface of the sample.