Measurement of sprinkler droplet size

Droplet distributions for rotating spray-plate sprinklers were measured usi ng a laser technology and a flour methodology. In general, both methods pro duced comparable results. The flour method tended to produce d(25), d(50) a nd d(75) values that were on the average about 0.20 mm (about 15% of the d5 0 value) larger than laser values. However the 0.20 mm difference is consis tent with what would be expected when nozzle pressure differences used with the two methods are considered. Both methods can be used to estimate dropl et distributions from rotary spray-plate irrigation sprinklers for practica l field application purposes.