Abstract: A pressure sensor assembly includes a pressure sensor having a support structure and a sapphire isolation member coupled to the support structure and forming a region between a first surface of the sapphire isolation member and the support structure. A second surface of the sapphire isolation member has a sapphire etch surface formed thereon and is positioned to interface with fluid from or coupled to a process. A process seal is positioned against the second surface of the sapphire isolation member to prevent fluid from passing by the pressure sensor assembly. Electrical leads couple to a polysilicon strain gauge pattern positioned in the region on the first surface of the sapphire isolation member, and the polysilicon strain gauge pattern is configured to generate electrical signals indicative of the pressure of the fluid when the sapphire isolation member deflects responsive to the pressure.

Abstract: A pressure sensor assembly includes a pressure sensor having a support structure and a sapphire isolation member coupled to the support structure and forming a region between a first surface of the sapphire isolation member and the support structure. A second surface of the sapphire isolation member is positioned to interface with fluid from or coupled to a process. Electrical leads couple to a polysilicon strain gauge pattern positioned in the region on the first surface of the sapphire isolation member, and the polysilicon strain gauge pattern is configured to generate electrical signals indicative of the pressure of the fluid when the sapphire isolation member deflects responsive to the pressure.

Abstract: A process pressure transmitter includes transmitter electronics disposed within a housing coupled to a pressure sensor formed by a cell body defining an interior cavity. A deflectable diaphragm separates the interior cavity into a first cavity and a second cavity. The deflectable diaphragm includes a groove region located around a periphery of the deflectable diaphragm.

Abstract: A process pressure transmitter includes transmitter electronics disposed within a housing. The transmitter electronics includes a communications circuit coupled to a processing system and an analog to digital converter disposed within the housing. The analog to digital converter electrically is coupled to the transmitter electronics. A pressure sensor comprises a cell body defining an interior cavity. A deflectable diaphragm comprising a second material is coupled to the cell body and separates the interior cavity into a first cavity and a second cavity. The deflectable diaphragm includes a groove region located around a periphery of the deflectable diaphragm. The first and second cavities each contain a dielectric fill-fluid, each of the fill fluids adapted to receive a pressure and exert a corresponding force on the diaphragm, and the diaphragm is deflectable in response to differences in the pressures received by the fill-fluids in the first and second cavities.

Abstract: A sensor body cell for use in a pressure sensor includes a metal housing and an insulating cell. The metal housing has a first cavity with a first conical inner surface. A portion of the first conical inner surface is concave. The insulating cell includes a first seal portion within the first cavity and forms a seal with the first conical inner surface.

Abstract: A sensor body cell for use in a pressure sensor includes a metal housing and an insulating cell. The metal housing has a first cavity with a first conical inner surface. A portion of the first conical inner surface is concave. The insulating cell includes a first seal portion within the first cavity and forms a seal with the first conical inner surface.

Abstract: A process variable transmitter for sensing a process variable of an industrial process includes a process variable sensor configured to sense a current process variable of the industrial process. Measurement circuitry is configured to compensate the sensed process variable as a function of at least one previously sensed process variable characterized by a Hysteron basis function model. Output circuitry provides a transmitter output related to the compensated sensed process variable.

Abstract: A capacitance-based pressure sensor for measuring a process variable includes a metal sensor body, a diaphragm disposed within a cavity of the metal sensor to form a deflectable capacitor plate, and an insulator extending through the metal sensor body from an end wall to the cavity. The pressure sensor further includes an isolation tube in fluid connection with the cavity, the isolation tube extending into the insulator through the end wall, a stationary capacitor plate on a surface of the insulator in the cavity, the stationary capacitor plate spaced from the diaphragm, and an electrical lead wire connected to the stationary capacitor plate and extending through the insulator parallel to the isolation tube and exiting the insulator at the end wall. A fill fluid is within the isolation tube and the cavity to apply pressure to the diaphragm.

Abstract: A pressure sensor includes a base having a high-pressure contact portion, and a diaphragm positioned over the base and having an external top surface opposite the base. The external top surface is defined within a closed perimeter and external side surfaces extend down from an entirety of the closed perimeter toward the base. A high-pressure contact portion of the diaphragm is aligned with and separated by a gap from the high-pressure contact portion of the base. A sensing element is coupled to the diaphragm and provides an output based on changes to the diaphragm. When a hydrostatic pressure load above a threshold value is applied to the entire external top surface and external side surfaces of the diaphragm, the hydrostatic pressure load causes the high-pressure contact portion of the diaphragm to contact the high-pressure contact portion of the base.

Abstract: A pressure sensor includes a base having a high-pressure contact portion, and a diaphragm positioned over the base and having an external top surface opposite the base. The external top surface is defined within a closed perimeter and external side surfaces extend down from an entirety of the closed perimeter toward the base. A high-pressure contact portion of the diaphragm is aligned with and separated by a gap from the high-pressure contact portion of the base. A sensing element is coupled to the diaphragm and provides an output based on changes to the diaphragm. When a hydrostatic pressure load above a threshold value is applied to the entire external top surface and external side surfaces of the diaphragm, the hydrostatic pressure load causes the high-pressure contact portion of the diaphragm to contact the high-pressure contact portion of the base.

Abstract: A differential pressure sensor for sensing a differential pressure of a process fluid, includes a sensor body having a sensor cavity formed therein with a cavity profile. A diaphragm in the sensor cavity deflects in response to an applied differential pressure. The diaphragm has a diaphragm profile. A gap formed between the cavity profile and the diaphragm profile changes as a function of the differential pressure. At least one of the cavity profile and diaphragm profile changes as a function of a line pressure to compensate for changes in the gap due to deformation of the sensor body from the line pressure.

Abstract: A capacitance-based pressure sensor for measuring a process variable includes a metal sensor body, a diaphragm disposed within a cavity of the metal sensor to form a deflectable capacitor plate, and an insulator extending through the metal sensor body from an end wall to the cavity. The pressure sensor further includes an isolation tube in fluid connection with the cavity, the isolation tube extending into the insulator through the end wall, a stationary capacitor plate on a surface of the insulator in the cavity, the stationary capacitor plate spaced from the diaphragm, and an electrical lead wire connected to the stationary capacitor plate and extending through the insulator parallel to the isolation tube and exiting the insulator at the end wall. A fill fluid is within the isolation tube and the cavity to apply pressure to the diaphragm.

Abstract: A process variable transmitter for sensing a process variable of an industrial process includes a process variable sensor configured to sense a current process variable of the industrial process. Measurement circuitry is configured to compensate the sensed process variable as a function of at least one previously sensed process variable characterized by a Hysteron basis function model. Output circuitry provides a transmitter output related to the compensated sensed process variable.

Abstract: A differential pressure sensor for sensing a differential pressure of a process fluid, includes a sensor body having a sensor cavity formed therein with a cavity profile. A diaphragm in the sensor cavity deflects in response to an applied differential pressure. The diaphragm has a diaphragm profile. A gap formed between the cavity profile and the diaphragm profile changes as a function of the differential pressure. At least one of the cavity profile and diaphragm profile changes as a function of a line pressure to compensate for changes in the gap due to deformation of the sensor body from the line pressure.

Abstract: A variable optical attenuator has a first and second waveguides that are optically coupled together. At least one of the waveguides has a movable cantilever portion that is movable relative to the other to control attenuation of an optical signal traveling between the two. Preferably, electrically driven actuators deflect the movable waveguides to a relative position at which a desired optical attenuation value is achieved. The electrically driven actuator receives a drive signal that controls the amount of deflection. The drive signal may be set to achieve a desired value for an electrical parameter that varies with the position of the movable waveguide and may be sensed by the electrically driven actuator. In some examples, the drive signal is set to achieve a desired capacitance or voltage difference between the movable waveguide and an electrode.

Abstract: A variable optical attenuator has a first movable waveguide support and a second waveguide support that include first and second waveguides, respectively, such that the first and second waveguides are aligned for propagating an optical energy. An electrically driven actuator positions the movable waveguide support for coupled, optical misalignment relative to the second support to achieve a desired optical attenuation value. The movable waveguide support may be in a cantilevered configuration in which a distal end extends over a surface having an electrode. In this example, applying a drive signal to the electrode deflects the movable support such that the signal coupled between the first waveguide to the second waveguide is attenuated. The drive signal may be set to achieve a desired value for an electrical parameter that varies with the position of the movable waveguide support.

Abstract: A variable optical attenuator has a first waveguide and a second waveguide that are optically coupled together. At least one of the waveguides has a movable cantilever portion that is movable relative to the other to control attenuation of an optical signal traveling between the two. Preferably, electrically driven actuators deflect the movable waveguides to a relative position at which a desired optical attenuation value is achieved. Each movable waveguide may deflect in an opposite direction to the other waveguide. The electrically driven actuator receives a drive signal that controls the amount of deflection. The electrically driven actuator may be an electrostatic, electrothermic, or electromagnetic actuator. In the example of an electrostatic actuator, one electrode may be disposed on a movable waveguide and another adjacent the moveable waveguide to create the electrostatic force that moves the waveguide.

Abstract: A variable optical attenuator has a first movable waveguide support and a second waveguide support that include first and second waveguides, respectively, such that the first and second waveguides are aligned for propagating an optical energy. An electrically driven actuator positions the movable waveguide support for coupled, optical misalignment relative to the second support to achieve a desired optical attenuation value. The movable waveguide support may be in a cantilevered configuration in which a distal end extends over a surface having an electrode. In this example, applying a drive signal to the electrode deflects the movable support such that the signal coupled between the first waveguide to the second waveguide is attenuated. The drive signal may be set to achieve a desired value for an electrical parameter that varies with the position of the movable waveguide support.