Patent ID: 6478547
Filing Date: 2002-11-12
Classification: F04B,Y10T

Abstract:
A method for dispensing a precise amount of a fluid utilizing a rolling membrane pumping system, said method comprising:determining an amount by which to change a dispense based at least in part on a shape of said membrane if a particular dispense is a first dispense; calculating an amount by which to change a dispense based at least in part on a predicted membrane flex if a particular dispense is other than a first dispense. wherein said predicted membrane flex is based at least in part on a maximum pump chamber pressure during said first dispense; moving a piston in a pump chamber of said pumping system based at least in part on said calculated amount; opening an output valve of said pumping system; monitoring said pump chamber pressure to detect a sudden decrease in said pump chamber pressure to signal a mechanical failure in said pumping system; and determining a maximum pressure in said pump chamber during said movement of said piston.