PDPA laser

The Phase Doppler Particle Analyser (PDPA) is a highly specialised technology to measure droplet velocities and sizes of sprays.

PDPA laser


The PDPA laser-based measuring set-up is composed of four different parts:

  • TSI PowerSight PDPA 1D system
    • a droplet passes through a small sampling volume, formed by two intersecting laser beams, scattering light by refraction. From the light scattering characteristics, droplet sizes and velocities are obtained
    • the equipment combines a laser-based optical transmitter, an optical receiver, an electronic signal processor and software for capturing and analyzing data
    • droplet diameter measuring range: 0.5 - 2153 μm
    • droplet velocity measuring range: 0 – 180 m s-1
  • Spray unit
    • insulated spray liquid tank (100 L) with fluid level control system, mechanical and hydraulic mixing system
    • air support system
    • liquid temperature control system
    • centrifugal pump
    • pressure regulator and a digital pressure gauge
  • Climate room
    • 8 m x 3.70 m x 3.37 m
    • ambient temperature range from 5 to 30°C
    • relative humidity range from 30 to 90%
  • 3D automated positioning system
    • allows to position the measuring point within the spray and to perform scan patterns
    • traverse range of 2.0 m x 2.2 m


  • Spray measurements (droplet size and velocity)
  • Evaluation and classification of sprays and spray nozzles
  • Evaluation of adjuvants
  • Size velocity correlation