Differential pressure sensor with line pressure measurement
AssigneeRosemount Inc.
InventorsJohn P. Schulte, David G. Tyson, Andrew J. Klosinski
Life of this patent
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Abstract
A pressure sensor assembly for sensing a pressure of a process fluid includes a sensor body having a cavity formed therein and first and second openings to the cavity configured to apply first and second pressures. A diaphragm in the cavity separates the first opening from the second opening and is configured to deflect in response to a differential pressure between the first pressure and the second pressure. A capacitance based deformation sensor is provided and configured to sense deformation of the sensor body in response to a line pressure applied to the sensor body.
Claims15
A pressure sensor assembly for sensing a pressure of a process fluid, comprising:
- a sensor body having a cavity formed therein and first and second openings to the cavity configured to apply first and second pressures;
- a diaphragm in the cavity separating the first opening from the second opening responsive to a differential pressure;
- a first electrode mounted outside of the sensor body arranged to form a first capacitance with the sensor body, wherein the first capacitance varies in response to line pressure of the process fluid due to deformation of the sensor body;
- and
- measurement circuitry coupled to the electrode arranged to measure the line pressure based upon the first capacitance.
A method for measuring differential pressure and line pressure of a process fluid comprising:
- mounting a deflectable diaphragm in a cavity in a sensor body;
- applying a first pressure of the process fluid to one side of the deflectable diaphragm in the cavity;
- applying a second pressure of the process fluid to another side of the deflectable diaphragm in the cavity;
- determining differential pressure based upon deflection of the deflectable diaphragm;
- forming a first capacitance with a first electrode positioned outside of the sensor body, the first capacitance formed between the electrode and the sensor body and having a capacitance which changes based upon deformation of the sensor body due to a line pressure of the process fluid;
- and
- determining a line pressure of the process fluid based upon changes in the capacitance.
Dependencies are inferred from the claim text.