Effects of operating pressure and nozzle height on uniformity of spray distribution pattern were investigated through laboratory experiments using five types of Teejet 11004 nozzles operated over three different heights and three different pressures. Effects of nozzle-tip materials on the uniformity was also observed. Degree of nonuniformity (DNU), which was defined using a spectral analysis, was used as the indicator of the distribution uniformity. A laboratory set-up, including a simulated boom-sprayer system, a test-condition monitoring system, and a spray-deposition measuring system, was developed. The spray-deposition measuring system used string collectors and a fluorometer to collect spray deposition data. Statistical analysis of the test data showed that nozzle height had a strong effect on spray distribution uniformity, but spray pressure had no significant effect on the uniformity. The experimental data also suggested that nozzles with nonmetal tips may provide a lower DNU than nozzles with metal tips.