Apparatus for measuring the amount of fluid supplied by a fluid supply device

A device for detecting and measuring the amount of fluid delivered by a fluid delivery device having a supply line for the fluid under pressure to the delivery device having an apportioning cross-section valve characterized by the fact that a piston means is integrated in the supply line, a pressure comparison valve responsive to spring means for providing a nominal value and for comparing the pressure contrast which appears at said apportioning cross-section valve with said nominal value in said pressure comparison valve and an adjustment device for providing a correcting regulation of said piston means, said adjustment device being activated in accordance with the deviation of said pressure contrast from said nominal value and wherein the position of said piston means provides a measure of the amount of flowing fluid per unit of time,

• a fluid tank, a return flow line connected to said fluid tank wherein a part of the apportioned amount of fluid is returned through said return line to the fluid tank characterized by the fact that in said return line a constant flowthrough cross-section orifice is provided and a differential pressure valve operatively associated with said flowthrough cross-section orifice for the generation of a constant pressure contrast at said flowthrough cross-section orifice,
• a relief line having a flowthrough cross-section means characterized by the fact that said differential pressure valve controls an outlet cross-section valve following said flowthrough cross-section means in said relief line, and
• a displacement-voltage converter connected to said piston means for generating an electrical control value signal directly proportional to the displacement of said piston means.