The aim of the work was to evaluate the influence of changes of technical working parameters of a field sprayer on changes of the coefficient of variation for double stream atomisers. The technical parameters were the height and the inclination angle of the sprayer boom and spraying pressure. In the studies, a Drift Guard TwinJet Flat Spray nozzle (DGTJ60 11003 VS) was used. It generated two flat fans of liquid at the spray angle of 110°, directed forward and backward in relation to the direction of sprayer movement. It has a 60° angle between its two fans. The measurement of the coefficient of variation of transverse liquid distribution was done using the Hardi Spray Scanner patternator. The obtained results indicate that the height of field boom setup, the angle of inclination, and their interaction had the strongest influence on the value of the coefficient of variation of transverse liquid distribution for the field boom equipped with the DGTJ60 11003VS nozzle. Field boom setup during the spraying at the height of 0.5–0.6 m, keeping field boom inclination from 0° to 2°, and using the liquid pressure of 0.4 MPa allowed for gaining the lowest values of the coefficient from 5.03% to 6.53%.