A short flash of light from a laser illuminates a screen, which acts as a bright background behind the subject spray. The short pulse from the laser freezes the motion, allowing blur-free visualization of drop size and shape. Images from the digital camera are transferred to a computer and high-speed real-time particle sizing software analyses the images obtained in order to build up the diameter distribution.
Individual Particle Measurements
Unlike Laser Diffraction systems, VisiSize captures images of the particles or droplets as they pass the measurement volume and measures these directly. Because individual particles are measured, there is no curve-fitting, no approximation and no ignored large particles.
Out of Focus Measurement
Our powerful size measurement algorithm is able to measure droplets and particles whether they are in focus or not. Our special calibration process allows the software to correct for the blurred particles and report the particle diameter as if it were perfectly in focus. This technique allows us to use the system in areas where it is difficult to present a 2-dimensional particle stream (such as in-situ particle size measurements on a production line).
Velocity Measurement
By double-pulsing the laser in a technique similar to PIV, size vs. velocity distributions may also be measured. For more information about the technique see our in-flight sizing datasheet.
Simple Calibration
Our complete systems come with standard calibrations, verified in the lab, to reduce set-up time and help prevent calibration errors. All you need to do is select the correct calibration file in the software, and your system is fully calibrated to measure in and out-of-focus droplets.
