Abstract: A control arrangement is provided which permits precise metering of a bellows pump. The control arrangement permits the predetermined setting of an amount of fluid to be dispensed from a single pump or a plurality of pumps. The control system permits a double bellows pump to cooperate with a drive mechanism in order to precisely meter the fluid to be dispensed from the pump by selecting a predetermined amount of fluid from a range of settings of the control mechanism. When a plurality of double bellows liquid dispensing pump units are provided, a plurality of electric motors are arranged to drive an adjustable stop element and provide a limit on the length of stroke of a driving rod connected to the bellows pump. The motors are controlled by a program logic circuit which monitors the degree of movement of the stop elements and controls the motors in response to a preset or selected fill condition.