Droplet Size Basics
The spray pattern of a nozzle is made up of many droplets of varying sizes. Droplet size is the diameter of an individual spray droplet and measured in microns (micrometers) often notated with the symbol µ. One micron equals 0.001 mm(0.0000394″); there are 25,400 microns in one inch. For example, the diameter of a human hair is about 100 microns.
Most nozzles have a wide array of droplet sizes. These droplet sizes are commonly summarized by statistical analysis based on testing from sophisticated droplet size measuring equipment.
Remember, droplet size can vary based on pressure. The same nozzle can produce medium droplets at low pressures and fine droplets at higher pressures.