## 2 Materials and Methods
### Penetration Cones  
Figure 2 shows the penetration cones used in experimental tests. Each of these cones is designed to meet different requirements in mechanical testing, depending on the materials being tested and the nature of the test being conducted [31; 32; 33]. The choice of tip angle is very important for obtaining accurate and relevant results based on the properties of the materials being tested, based in correlation with methods of the European Pharmacopoeia [34]. It is mentioned that the choice of the cone angle was 9, 19, and 90 degrees adapted to the universal test equipment Hounsfield HK 1S being used for mechanical testing depending on the tested material (here, mold cheese). The image in Figure 2 shows the three cones with different geometries, each with a distinct tip angle, used in the experiments. Having made a brief analysis, based on the distinct tip angle, the following can be specified:  
1. Tip angle of 9 degrees. This cone has a very sharp tip angle (Figure 2a). Its geometry suggests that it is used for fine and precise penetration into the material. It is suitable for soft materials or for tests that require minimal penetration with a very acute angle. 2. Tip angle of 19 degrees. This cone has a moderate tip angle, larger than the 9-degree one but still relatively sharp (Figure 2b). It can be used for tests that require deeper penetration than achievable with the 9-degree cone while still maintaining a certain level of precision. It is appropriate for slightly harder materials. 3. Tip angle of 90 degrees. This cone has a wide tip angle of 90 degrees (Figure 2c). It is the least sharp of the three. It is used for penetrating harder materials or for tests \begin{table}
\begin{tabular}{c c} \hline \hline
**Characteristic Name** & **Values** \\ \hline Nominal Force (F\({}_{\text{nom}}\)) & 1 kN \\ \hline Maximum Operating Force (F\({}_{\text{om}}\)) & \(\leq\)125\% \\ \hline Output Signal Options & 0–10 V/4–20 mA \\ \hline Nominal Supply Voltage & 24 V \\ \hline Supply Voltage Range & 12–36 V \\ \hline Relative Linearity Error & \(\leq\)0.5\% \\ \hline Hysteresis & \(\leq\)0.05\% \\ \hline Relative Repeatability Error & \(\leq\)0.05\% F\({}_{\text{nom}}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Technical and functional characteristics of the HTE 1 kN force sensor. Figure 2: Geometry of the cones: (**a**) cone (from steel) with a tip angle of 9 degrees; (**b**) cone (from bronze) with a tip angle of 19 degrees; (**c**) cone (from bronze) with a tip angle of 90 degrees; (**d**) diagram of the forces acting on the sample. that require a larger contact surface at the point of penetration. It can be useful in evaluating materials that require high resistance to deformation. The geometric constant of the cone, \(\mathrm{k_{cone}}\), is obtained from the diagram of the forces acting on the sample during penetration (Figure 2d) and is calculated using the following relation [24]:  
\[k_{cone}=\frac{1}{\pi}\frac{cos^{3}(\alpha/2)}{sin(\alpha/2)} \tag{1}\]  
where: \(\mathrm{k_{cone}}\) is the cone constant and \(\alpha\) represents the tip angle of the cone. In the end, Figure 2d graphically shows the forces that appear when the cone penetrates the material (mold cheese): penetration force, \(\mathrm{F_{P}}\), in N; normal force, \(\mathrm{F_{n}}\), in N; tangential force, \(\mathrm{F_{t}}\), in N; the penetration depth of the cone, h, in mm. These forces, during the cone's penetration into the material (mold cheese) generate/produce: \(\mathrm{F_{P}}\)--the deformation of the material, in mm (it takes the shape of the tip of the cone, whose contact area between the material and the cone will be A, in mm\({}^{2}\)); \(\mathrm{F_{n}}\)--normal stresses, \(\mathrm{\sigma}\), in N/mm\({}^{2}\) and \(\mathrm{F_{t}}\)--tangential stresses, \(\mathrm{\tau_{c}}\), in N/mm\({}^{2}\).