Sizing software is combined with a pulsed laser that eliminates motion blur and visualises the effect of nozzles developed to combat the spray drift problem
The problem of pesticides drifting from the area in which they are required leads to pollution and inefficient use of pesticides.
In the 1980s and 90s, institutions in Europe and the Spray Drift Task Force in the USA were established to look at ways of minimising this worldwide problem.
After extensive practical trials it has been concluded that droplet size is one of the most important factors affecting spray drift.
Oxford Lasers's VisiSizer systems are now being used to characterise the size spectrum of sprays produced by new nozzle designs for pesticide sprays.
Sizing software is combined with a pulsed laser that eliminates motion blur and visualises the effect of new air-inclusion nozzles that have been developed to combat the spray drift problem.
Droplets produced by one of these devices can contain bubbles, consequently making sizing difficult for alternative techniques.
The VisiSizer system employs a back illumination technique and droplets appear as black on a white background.
Particle can be sized at the rate of 7680 drops per second in real time.
The droplets can be of any shape or size and can even be non-spherical.
VisiSizer is not deceived by out-of-focus droplet images, says Oxford Lasers.
By measuring the sharpness of the image edges, VisiSizer automatically corrects for this effect.
VisiSizer is not only able to see droplets clearly, but has produced unique images of droplets that contain air bubbles.
While drop size and velocity distribution information is vital in developing pesticide spray nozzles, it is the interaction of droplets with plants that determines the effectiveness of the delivery system and whether the droplets stay on the plant/leaf or bounce off to form a drift problem.
A sequence of images captured by VisiSizer can be viewed as a movie.
This then shows exactly how many droplets are bouncing off the plant/leaf on impact and how many are adhering to the surface.
The Oxford Lasers range of VisiSizer systems can also be used to measure bubble columns, deodorant sprays, hair sprays, fire suppression sprays, fuel injector sprays, airborne powders, paint sprays, inkjet printer sprays, medical device sprays, and many others.
