A device for spreading active agents comprising: a boom, which is arranged pivotably about a rotation axis； a sensor arrangement for the detection of an angular velocity of the boom about the rotation axis； a sensor for the detection of an angular position of the boom； a control unit processing output signals from the sensor； and an actuator, acting on the present angular position of the boom based on control signals from the control unit. For the determination of an angular position of the boom, the control unit calculates an angular position of the boom in relation to a reference plane by integration of the angular velocity and merges the angular position calculated by means of the angular velocity, with the detected angular position to determine the present angular position of the boom to return the boom to a desired angular position.
