A pressure sensor measures pressure by measuring the deflection of a MEMS membrane using a capacitive read-out method. There are two ways to implement the invention. One involves the use of an integrated Pirani sensor and the other involves the use of an integrated resonator, to function as a reference pressure sensor, for measuring an internal cavity pressure.

An apparatus and associated method, for controlling signal passage, includes a first passageway for a first fluid, a second passageway for a second fluid, and an interposed chamber. A first, movable diaphragm at a first chamber junction and a second, movable diaphragm at a second chamber junction, with a third fluid bound there between and interposed between the first and second passageways. A device varies a volume of the third fluid bound between the diaphragms and thus moves the diaphragms. A movable member and a reservoir of the device are configured such that the movable member is sufficiently movable to increase the volume of the reservoir to remove a sufficient portion of the third fluid bound between the first and second diaphragms from the chamber to cause the first and second diaphragms to be pressed against the first and second walls, respectively.

An apparatus, for controlling signal passage, includes a first passageway for a first fluid, a second passageway for a second fluid, and an interposed chamber. A first, movable diaphragm at a first chamber junction and a second, movable diaphragm at a second chamber junction, with a third fluid bound there between and interposed between the first and second passageways. A device varies a volume of the third fluid bound between the diaphragms and thus moves the diaphragms. The diaphragms each have at least one position that permits passage of a pressure signal between the first fluid in the first passageway and the second fluid in the second passageway through the third fluid bound between the diaphragms. The diaphragms each have at least one position that prohibits passage of a pressure signal.

A pressure sensor measures pressure by measuring the deflection of a MEMS membrane using a capacitive read-out method. There are two ways to implement the invention. One involves the use of an integrated Pirani sensor and the other involves the use of an integrated resonator, to function as a reference pressure sensor, for measuring an internal cavity pressure.

A pressure sensor includes a first wafer having a primary deflectable diaphragm and a secondary deflectable diaphragm. The primary deflectable diaphragm has a first relationship between applied pressure and deflection, and the second deflectable diaphragm has a second relationship between applied pressure and deflection. The first and second relationships differ from one another. A second wafer is attached to the first wafer. At least one tensile strain gauge is coupled to the primary deflectable diaphragm and at least one compressive strain gauge coupled to the secondary deflectable diaphragm. An overpressure feature is mounted relative to one of the first wafer and the second wafer. The overpressure feature is configured to contact the other of the first wafer and second wafer during an overpressure condition that exceeds a maximum measurement pressure of the primary deflectable diaphragm and a maximum measurement pressure of the secondary deflectable diaphragm.