Line pressure measurement using differential pressure sensor
First Claim
1. A pressure sensor assembly for sensing a pressure of a process fluid, comprising:
- a sensor body having a cavity formed therein, the cavity configured to couple to a process fluid pressure and change in size in response to the process fluid pressure;
a deflectable diaphragm in the cavity configured to deflect in response to the first process fluid pressure;
a primary electrode coupled to a wall of the cavity to form a primary capacitor between the primary electrode and the deflectable diaphragm;
a secondary electrode coupled to the wall of the cavity to form a secondary capacitor between the secondary electrode and the deflectable diaphragm; and
circuitry coupled to the primary capacitor and the secondary capacitor configured to calculate a line pressure of the process fluid as a function of variation in at least the primary capacitor and the secondary capacitor due to change in the size of the cavity from the process fluid pressure.
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Accused Products
Abstract
A pressure sensor assembly for sensing a pressure of a process fluid includes a sensor body having a cavity formed therein to couple to a process fluid pressure. A deflectable diaphragm in the cavity deflects in response to the first and second process fluid pressures. A first primary electrode couples to a wall of the cavity and forms a first primary capacitor between the first primary electrode and the deflectable diaphragm. A first secondary electrode couples to the wall of the cavity to form a first secondary capacitor between the first secondary electrode and the deflectable diaphragm. A second primary electrode and second secondary electrode are preferably coupled to a wall of the cavity opposite the first. Line pressure of the process fluid is determined based upon variation in the secondary capacitors relative to the primary capacitors.
83 Citations
25 Claims
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1. A pressure sensor assembly for sensing a pressure of a process fluid, comprising:
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a sensor body having a cavity formed therein, the cavity configured to couple to a process fluid pressure and change in size in response to the process fluid pressure; a deflectable diaphragm in the cavity configured to deflect in response to the first process fluid pressure; a primary electrode coupled to a wall of the cavity to form a primary capacitor between the primary electrode and the deflectable diaphragm; a secondary electrode coupled to the wall of the cavity to form a secondary capacitor between the secondary electrode and the deflectable diaphragm; and circuitry coupled to the primary capacitor and the secondary capacitor configured to calculate a line pressure of the process fluid as a function of variation in at least the primary capacitor and the secondary capacitor due to change in the size of the cavity from the process fluid pressure. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method of determining a line pressure of a process fluid, comprising:
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applying a pressure of the process fluid to a sensor body having a cavity formed therein and responsively causing a size of the cavity to change, the cavity including a deflectable diaphragm and a primary electrode which forms a primary capacitor with the diaphragm, the sensor body further including a secondary electrode forming a secondary capacitor with a cavity; calculating the line pressure of the process fluid as a function of variation in at least the primary capacitor and the secondary capacitor due to change in the size of the cavity in response to the process fluid pressure. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19)
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20. A pressure sensor comprising;
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a deflectable diaphragm configured to receive first and second pressures applied to opposing sides; first and second primary electrodes configured to form first and second primary capacitors with the deflectable diaphragm; first and second secondary electrodes configured to form first and second secondary capacitors with the deflectable diaphragm; circuitry configured to calculate differential pressure and further configured to calculate line pressure as a function of variations in the first and second primary capacitors and first and second secondary capacitors. - View Dependent Claims (21, 22, 23, 24, 25)
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Specification