Phase Doppler Interferometer (PDI)
![](/en-mg/-/media/dam/industrial/usa/website-images/sars---equipment-and-services/characterization-overview-phase-doppler-interferometer-660x370.jpg?h=270&w=480&hash=7F6DB45EEED303A42B2212858E9FA07D)
Phase Doppler Interferometer (PDI) instruments measure drop size, velocity and volume flux at a point within a spray plume. These instruments provide the most detailed information of the spray characteristics by characterizing each droplet that passes through the probe volume and building up accurate ensemble statistics.
PDI Overview
The probe volume is formed by two (or four) intersecting laser beams, which provide a non-intrusive, high spatial-resolution measurement point. Spray pattern characterization can be performed by moving either the instrument or the nozzle itself and collecting data at numerous specified locations. This information is then combined to represent the drop size, velocity or volume flux distribution throughout the spray pattern. Further analysis with the Phase Doppler Particle Analyzer (PDPA) allows combination of the information from the many individual data points to provide volume flux and area weighted average spray pattern statistics. Spraying Systems Co. primarily uses PDI-HD, PDI-Standard and PDI-Turnkey instruments.