Abstract: A method and system for providing dosing of fluid is described. The method and system is directed to the control of a plurality of parallel on/off valves which regulate the flow of the fluid. The system includes a plurality of base control valves for delivering a base flow amount. The base control valves are preferably arranged to have binary graduation of their respective flow rates. These base control valves are optionally discontinuously switched on and/or off for delivering the base flow amount. A "timed" valve is varied according to pulse-width modulation techniques to deliver a continuously variable partial flow. The control of the timed valve is effected by electrical circuitry which generates a feedback error signal related to the flow quantity.

Abstract: A volumetric direct gas meter is driven by a servomotor and the rotational speed of the motor is regulated in response to the pressure differential between the inlet and outlet ports of the meter so that the pressure tends to zero.