## 3 Test Results Used to Verify the ANN Model  
In order to carry out the experimental verification of the aforementioned artificial neural network, in-situ brick wall moisture tests were carried out on two historic buildings erected at the end of the 19 th century, for which full ceramic brick and lime mortar were used. The research was carried out in autumn during cloudy days with no wind, sun, or rain. The outside air humidity was around 75% and the temperature was about 16 \({}^{\circ}\)C. The indoor relative humidity was 85% \(\pm\) 5% and the air temperature was 18 \({}^{\circ}\)C \(\pm\) 3 \({}^{\circ}\)C.  
Figures 4 and 5 present photos from the examined objects. In turn, the characteristics of the objects are given in Table 1. In the case of both buildings, traces of moisture are clearly visible on their walls, and the height of the capillary water fringe reaches over 100 cm above the ground level.  
Figure 4: Photographs of selected fragments of a former farm building in Katy Wroclawskie.  
Figure 5: Pictures of selected fragments of the Redemptorist monastery in Wroclaw.  
Table 2 contains a set of data consisting of 15 sets of results, which were obtained on the basis of the tests of the historic buildings described above. Sets 1 to 7 were obtained from the post-farm building in Katy Wroclawskie and sets 8 to 15 from the monastery building in Wroclaw. As with previous studies [29], each set of results included two dimensionless parameters \(X_{\text{D}}\) and \(X_{\text{M}}\), determined nondestructively using the dielectric (with the use of the Gann Hydromette Uni 2 meter with an active ball probe) and microwave (with the use of the Trotec T 600 meter) methods, respectively; three parameters \(A\), \(C\), and \(S\), describing the molar concentrations of nitrate, chloride, and sulfate salts in walls, determined using the semi-quantitative method; as well as the \(U_{m}\) parameter obtained using the gravimetric method (with the use of a laboratory dryer), describing the actual mass humidity of the wall (in%). The samples were dried at a temperature of + 105 \({}^{\circ}\)C \(\pm\) 1 \({}^{\circ}\)C.  
\begin{table}
\begin{tabular}{l l} \hline \multicolumn{2}{c}{**Description of the Object**} \\ \hline \multicolumn{2}{c}{**OBJECT NO. 1**} \\ \hline Name, location & post-farm building, \\  & Katy Wroclawskie, Poland \\ \hline Date of construction & end of the nineteenth century \\ \hline \multirow{4}{*}{Description of the object} & \multirow{2}{*}{\begin{tabular}{l} erected on a rectangular plan with dimensions of 55.0 m \(\times\) 10.0 m \\ the building has no basement, has two floors above ground, and a barren \\ attic covered by a steep gable roof \\ served as an economic function for farm buildings; currently has a \\ residential and service function \\ \end{tabular} } \\ \hline \multirow{2}{*}{Place of measurement} & \multirow{2}{*}{\begin{tabular}{l} brick basement walls \\ wall thickness in the range of 51 cm to 64 cm \\ \end{tabular} } \\ \hline \multicolumn{2}{c}{**OBJECT NO. 2**} \\ \hline Name, location & Redemptorist monastery, \\  & Wroclaw, Poland \\ \hline Date of construction & end of the nineteenth century \\ \hline \multirow{2}{*}{Description of the object} & \multirow{2}{*}{\
\begin{tabular}{l} erected on a rectangular plan with dimensions of 27.0 m \(\times\) \(\sim\)17.0 m \\ basement, two floors above ground, and a usable attic covered with a steep gable roof \\ \end{tabular} } \\ \hline \multirow{2}{*}{Place of measurement} & \multirow{2}{*}{
\begin{tabular}{l} brick walls of the basement—external and internal \\ wall thickness in the range of 55 cm to 75 cm \\ \end{tabular} } \\ \hline \end{tabular}
\end{table}
Table 1: Characteristics of the facilities where the tests were conducted for the purpose of verifying the artificial neural network.  
Table 3 summarizes selected statistical characteristics of the obtained test results.