A pdpa laser-based measuring set-up for the characterisation of spray nozzles.

The characteristics of agricultural sprays belong to the most critical factors affecting spray drift, deposition on plants, spray coverage and biological efficacy. Hence, within the framework of a research project about agricultural spray drift, a measuring set-up for the characterisation of spray nozzles using a Phase Doppler Particle Analyser (PDPA) was developed. This set-up is able to measure droplet sizes and velocities based on light-scattering principles. It is composed of different parts i.e.: a climate room, a spray unit, a three-dimensional automated positioning system and an Aerometrics PDPA 1D system. This paper presents a detailed description of this measuring set-up along with some first measuring results. These measurements will be used as an input for a Computational Fluid Dynamics drift-prediction model and to classify nozzles based on their driftability.