MEASURING DROPLET SIZE OF AGRICULTURAL SPRAY NOZZLES−MEASUREMENT DISTANCE AND AIRSPEED EFFECTS

摘要: With a number of new spray testing laboratories going into operation and each gearing up to measure atomization from agricultural nozzles using laser diffraction, establishing following set scientific standard procedures is crucial long-term data generation standardization across the industry. It has long been recognized that while offering ease use as compared other methods, diffraction measurements do not account for measurement bias effects due differential velocities between differing sized droplets, in many cases significantly overestimate fine droplet portion spray. Droplet sizes were measured three flat fan (8002, 8008, 6510) at pressures (138, 276, 414 kPa) four downstream distances (15.2, 30.5, 45.7, 76.2 cm) range concurrent air (0.7–80.5 m/s). At below 6.7 m/s, large gradients resulted overestimation both 10% volume diameter (Dv0.1) by more than percent less 100 μm (V<100) was overestimated twoto three-fold. The optimal distance reduce 5% found be 30.5 cm with velocity m/s measuring size ground nozzles. For aerial nozzles, 45.7 cm. Use these methods provides accurate efficacy drift assessments, increases inter-lab reproducibility.