Patent ID: 7043960

Claim:
A self-calibrating pressure transducer for accurately measuring process created pressure, comprising: a pressure transducer membrane; a calibration chamber including an isolation calibration membrane and containing a quantity of a calibration substance; an interior transducer chamber in operable flow communication with both said pressure transducer membrane and said isolation calibration membrane; said interior transducer chamber further including a first section in flow communication with said pressure transducer membrane and a second section in flow communication with said isolation calibration membrane, with both said first and second sections of said interior transducer chamber substantially full of a fill fluid; a first two-way valve disposed between said first and second sections of said interior transducer chamber, said first two-way valve having a selectable open mode for allowing flow communication between said first and second sections and further having a selectable closed mode for preventing flow communication between said first and second sections; a process isolation chamber having a process isolation membrane disposed for deflection by said process created pressure, with said process isolation chamber substantially full of a fill fluid; a second two-way valve disposed between said process isolation chamber and said interior chamber, said second two-way valve having a selectable open mode for allowing flow communication between said process isolation chamber and said first section of said interior chamber and further having a selectable closed mode for preventing flow communication between said process isolation chamber and said first section interior chamber; said self-calibrating pressure transducer automatically assuming a self-calibration mode responsive to selective positioning of said second two-way valve in said closed mode and selective positioning of said first two-way valve in said open mode, allowing a precisely measurable amount of calibration substance to enter said calibration chamber, thereby deflecting said isolation calibration membrane, forcing fill fluid to pass through said open first two-way valve, impacting and deflecting said pressure transducer membrane with a measurable force comparable to the known deflective force on the isolation calibration membrane, thereby self-calibrating the pressure transducer; and, said self-calibrating pressure transducer automatically assuming an operation mode responsive to selective positioning of said first two-way valve in said closed mode and selective positioning of said second two-way valve in said open mode, allowing process created pressure to deflect the process isolation membrane, forcing the fill fluid to pass through the open second two-way valve and impacting and deflecting said pressure transducer membrane in order to measure the process created pressure.