## 3 Results and Discussion
To achieve the second objective of determining the volume distribution and evaluating the variation of CV(D30) for a single nozzle as a function of varying measurement time, the average volumetric diameter D30 was used. The diameter represents a homogeneous set with the same number of drops and the same total volume of drops measured during tests performed with a PDA analyzer. The method for determining the volume distribution is presented in the works [16; 40]. Based on the recorded droplet diameters, the volume of liquid at the assumed points of the liquid stream was calculated, which made it possible to assess its distribution. Verification of the obtained results and evaluation of their variability was carried out by conducting volume distribution tests on a bench equipped with a groove table. Preliminary results for such an innovative method of evaluating the volume distribution of sprayed liquids were presented in paper [40]. Histograms of the distribution of the volumes, based on PDA analyzer tests using a bench equipped with a groove table, for a nozzle (AirMix 11003) selected from the group of test nozzles, are presented in Figure 12.  
Given that the two measurement methods used different representative volume measurements (sampling method and significantly different volumes of liquids analyzed), regularity was observed in the evaluation of volume distributions during the study (Figure 12). The distributions were also found to be cyclical over the time intervals assumed in the study. However, as the measurement time was reduced (smaller droplet counts to determine the volume diameter of D30), there was little variation in the arrangement of the distribution, especially for the volumes representing neighboring measurement points. Table 5 and Figure 13 show the results of the measurements in the form of CV(D30) coefficients of variation, taken as a relative measure for evaluating volume distribution. The results were tabulated for discrete values of time T (120, 80, 60, 40, 20, 10) s. In order to validate the results obtained with the PDA analyzer, the results of the CV coefficients of variation, determined from the volumes measured on the bench equipped with the groove table, were also tabulated. Between the CV value obtained from the groove table tests and the maximum CV(D30), there was a gap expressed in percentage points: (i) AirMix 11003--2.7; (ii) MMat 11003 EZ--4.0; (iii) TeeJet 11001 VS--1.7; (iv) MMat 11003 RS--2.2; (v) AirMix 11002--5.3. A similar trend in the variability of the coefficient results was noted as in the evaluation of differences in median volume diameter. The AirMix (11002, 11003) and MMat11003 EZ nozzle group had greater stability of results and smaller differences in coefficient of variation values within the range of measurement times adopted in the study from T = (120, 80, 60) s. In these time ranges, the difference values recorded were (i) AirMix 11003--0.8; (ii) AirMix 11002--1.3; and (iii) MMat 11003 EZ--2.1 percentage points. For nozzles with smaller diameters in the spectrum, regularity was observed in the evaluation of differences in coefficient of variation values. For the MMat 11003 RS nozzle, this was 3.7 percentage points over the full range of measurement times T = (120, 80, 60, 40, 20, 10) s. For the TeeJet 11001 VS nozzle, this was 1.9 percentage points over the range of measurement times T = (120, 80, 60, 40, 20) s.  
The third objective was an attempt to combine the results of transverse volume distribution obtained for single nozzles on the boom and comparing them with test results obtained on the groove table. The idea behind the proposed concept was to use the volume distribution results determined from the volume diameters (D30). From the volumes of liquid collected from the individual grooves of the table and the volumes of liquid during the PDA test, so-called \"virtual\" spray booms were constructed. Based on the results obtained in this way, the values of the coefficients of variation of the distribution (Table 6) were calculated for the boom section.