Preliminary spray nozzle characterization activities through shadowgraphy at the AgroForestry Innovation Lab (AFI-Lab)

Wind Tunnel Evaluation of Plant Protection Products Drift Using an Integrated Chemical–Physical Approach

“…To select the nozzle specimens to mount on the machine, the flow rate of each candidate specimen was measured in a dedicated test bench. The procedure and the equipment used are outlined in [48]. For each type of nozzle, the 10 which guaranteed the smallest coefficient of variation (CV, defined as the ratio between standard deviation and average) were selected and mounted on the machine.…”

“…The drop size distribution (DSD) of the nozzle population was obtained using PDIA at the laboratory located at unibz, where a VisiSize N60 PDIA system is installed (Oxford Lasers, Didcot, Oxfordshire, UK). At least four randomly selected nozzles from each configuration were tested in the dedicated test bench, seen in Figure 4, and described in greater detail in [48,49].…”

“…The drop size distribution (DSD) of the nozzle population was obtained using PDIA at the laboratory located at unibz, where a VisiSize N60 PDIA system is installed (Oxford Lasers, Didcot, Oxfordshire, UK). At least four randomly selected nozzles from each configuration were tested in the dedicated test bench, seen in Figure 4, and described in greater detail in [48,49]. For AI nozzles, the analyses were performed with the specimen spraying down wards in a vertical position, mounting the instrument so that its field of view (FOV) was Barcelona, Spain) and the proper functioning of the MOUDI was assessed by checking in the control module that the pressure drop across the impactor stages was consistent with the manufacturer's specifications (supporting Figure S2).…”

“…The 50th is also defined as the Volume Median Diameter (VMD). The relative span (RS) is a measure of how dispersed the DSD is and is calculated as in Equation ( 1 The data were extracted from the automatically generated test reports from the VisiSize 6.5.44 software and visualized in MATLAB (The MathWorks, Inc., Natick, MA, USA), readapting the dedicated scripts described in [49]. The main results of the analysis are the DSD of the nozzles, both in terms of number and volume: droplets are classified based on their diameter and, for each class, both the number and the fraction of the total sprayed volume represented by the droplets are recorded.…”