Abstract: An arrangement for calibrating a Venturi valve includes a source of flow measurements and a processing circuit. The Venturi valve has a variable shaft position and is operable to provide an air flow corresponding to the variable shaft position. The processing circuit is operable to provide a plurality of voltages to an actuator, the actuator operable to change the variable shaft position dependent on said plurality of voltages. The processing circuit is also operable to receive from the source of flow measurements a flow measure for each variable shaft position corresponding to each of the plurality of voltages. The processing circuit is further operable to store information representative of the relationship between each of the plurality of voltages and the flow measures.