The device has transceiving units (13,14) for emitting electromagnetic waves on material particles distributed in wide spreading on bottom surface of throwing vanes (7). The transceiving units receive reflected waves from material particles. The transceiving units have on-board computer and radar beam radar sensor. An evaluation unit evaluates received reflected electromagnetic waves from material particles, located in the air waves and determines distribution parameter such as direction of flight, flight speed, spray rate and/or distribution accuracy of discharged material particles.
