Patent ID: 8136707

Claim:
A fluid dispensing system for dispensing a liquid, comprising: a fluid dispenser supporting a barrel including a piston therein, the barrel including a chamber on a rear side of the piston and a liquid on a forward side of the piston; a positive pressure fluid circuit comprising components operable to apply a positive fluid pressure to the rear side of the piston; a negative pressure fluid circuit comprising components operable to apply a negative fluid pressure to the rear side of the piston; a first pressure transducer operable to sense a fluid pressure in the chamber; and a dispenser control having an input electrically connected to the first pressure transducer and outputs electrically connected to a component in the positive pressure fluid circuit and to a component in the negative pressure fluid circuit, the dispenser control storing a pressure-time relationship during a first dispensing cycle of the barrel and thereafter, operating the component in the positive pressure fluid circuit to maintain the pressure-time relationship during each subsequent dispensing cycle of the barrel such that the dispensing cycle time is the same for each dispensing cycle.