## 2 Materials and Methods
The analyzer probes were placed on a three-axis traverse system, enabling automated multipoint measurement in the measurement space. The 3D traverse system had a positioning resolution of 10 \(\upmu\)m and was controlled by 2D-LDA/PDA analyzer software. During the tests, subsequent droplets passed through a small sample volume in the area of two intersecting laser beams, scattering the light by refraction [24; 25; 26]. The receiving optics were set at an angle of 43.5\({}^{\circ}\) in relation to the laser beam, which ensured the dominance of the refraction of the light scattering mode. For the receiving probe, a B-type aperture mask (average size up to 644.2 \(\upmu\)m) and a 0.2 mm gap were used in the test. Table 1 presents the main parameters of the 2D-LDA/PDA analyzer. The spectrum of the droplets produced by the nozzle was examined at a pressure of 3 bar. Measurements were made by spraying water at a temperature of 20 \(\pm\) 2 \({}^{\circ}\)C. Environmental conditions were kept constant by conducting tests at a temperature of 20 \(\pm\) 2 \({}^{\circ}\)C and relative humidity of 40%-80%. Measurements were made at a measuring distance of hz = 0.4 m from the nozzle (Figure 3) (ISO/FDIS 25358-2018) [27]. The assumed measuring height is consistent with the height of the nozzle position above the surface of the multigrooved table, which was adopted during tests and for evaluation of the transverse distribution of liquid volume. A multipoint measurement was made in the x-axis of the nozzle, with a measuring step of \(\Delta\)x = 25 mm. [PERSON] and [PERSON] (1993) showed the usefulness of this method for measuring the properties of agricultural spraying and found that a single measurement along the long axis gave an appropriate representation of the entire spraying process [28]. \begin{table}
\begin{tabular}{l c} \hline Probe focal length & 700 mm \\ \hline Wavelength of laser beams & 660 nm and 785 nm \\ \hline Laser power per pair of beams for the first component: & 90 mW \\ Laser power per pair of beams for the second component: & 70 mW \\ \hline Diameter of the laser beam at the front lens & 2.75 \(\pm\) 0.25 mm \\ \hline Detection system adapted for measurements at the wavelengths compatible with the transmitting probe (i.e., 660 and 785 nm) \\ \hline Built-in camera for monitoring and adjusting LDA and PDA optics \\ \hline Range of measured particle sizes depending on configuration & 1–1600 \(\upmu\)m \\ \hline Resolution of measured quantities & \(\pm\)0.05 \(\upmu\)m \\ \hline Measurement of the maximum number of particles & \(>\)300,000 particles/second \\ \hline Range of measured velocity components at any vector return & 0–300 m/s \\ \hline Resolution of measured speeds in the range & 0.002\% \\ \hline \end{tabular}
\end{table} 
Table 1: Main 2D-LDA/PDA analyzer parameters. Figure 2: The analyzer 2D-Laser Doppler Anemometry/Phase Doppler Anemometry (2D-LDA/PDA) from Dantec Dynamics. Figure 3 shows the 44 discrete measuring points during measurement with a PDA analyzer in the spray stream, in which the droplet size and number were measured. The positioning of the PDA analyzer measuring space was carried out on the basis of a defined traverse measuring grid. The subsequent positions of the measuring space correspond to the midpoints of the measuring grooves of the table used in the method for assessment of the transverse liquid volume distribution. The measurement at each point was made for a measurement time of t = 180 s.  
During the measurements, the average diameters were recorded for each measuring point, namely arithmetic, surface, volumetric, Sauter (D10, D20, D30, D32), and volumetric diameters, below which smaller drops represent 10%, 50%, 90%, and 98% of the total volume at this point (Dv0.1, Dv0.5, Dv0.9 and Dv0.98, respectively). Relative span factor (RSF) values and percentage of total droplet volume less than 100 \(\upmu\)m were also recorded at subsequent measuring points (V100).