Measurement of Sprinkler Droplet Size

Droplet distributions for rotating spray-plate sprinklers were measured using a laser technology and a flour methodology. In general, both methods produced comparable results. The flour method tended to produce d sub 25 , d sub 50 and d sub 75 values that were on the average about 0.20 mm (about 15% of the d sub 50 value) larger than laser values. However, the 0.20 mm difference is consistent with what would be expected when nozzle pressure differences used with the two methods are considered. Both methods can be used to estimate droplet distributions from rotary spray-plate irrigation sprinklers for practical field application purposes.