Capacitive pressure sensor
First Claim
1. A pressure sensor, comprising:
- a probe body comprising a pressure deflectable diaphragm end formed of a first material having a first coefficient of thermal expansion, the diaphragm end including a first surface at least partially defining a first portion of a capacitor;
a relatively non-deformable component formed of a second material having a second coefficient of thermal expansion, the relatively non-deformable component including a second surface spaced from the first surface, the second surface at least partially defining a second portion of the capacitor; and
an intermediate component disposed at a peripheral region, the intermediate component isolating the pressure deflectable diaphragm end and the relatively non-deformable component from each other, the intermediate component being formed of a third material having a third coefficient of thermal expansion;
wherein the third coefficient of thermal expansion is less than the first coefficient of thermal expansion.
3 Assignments
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Accused Products
Abstract
Pressure sensors and their methods of use are described. In one embodiment, a pressure sensor includes a pressure deflectable diaphragm end formed of a first material with a first coefficient of thermal expansion, and a relatively non-deformable component formed of a second material having a second coefficient of thermal expansion. The pressure deflectable diaphragm end and the non-deformable component form a first and a second portion of a capacitor. An intermediate component separates, or is disposed between, the pressure deflectable diaphragm end and the relatively non-deformable component. The intermediate component is formed of a material with a coefficient of thermal expansion that is less than the first coefficient of thermal expansion which may help minimize changes in span with temperature. In other embodiments, a pressure sensor includes an intermediate circuit located between a distal end of the pressure sensor and a remotely located circuit enclosure including a main circuit.
80 Citations
36 Claims
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1. A pressure sensor, comprising:
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a probe body comprising a pressure deflectable diaphragm end formed of a first material having a first coefficient of thermal expansion, the diaphragm end including a first surface at least partially defining a first portion of a capacitor; a relatively non-deformable component formed of a second material having a second coefficient of thermal expansion, the relatively non-deformable component including a second surface spaced from the first surface, the second surface at least partially defining a second portion of the capacitor; and an intermediate component disposed at a peripheral region, the intermediate component isolating the pressure deflectable diaphragm end and the relatively non-deformable component from each other, the intermediate component being formed of a third material having a third coefficient of thermal expansion; wherein the third coefficient of thermal expansion is less than the first coefficient of thermal expansion. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A pressure sensor, comprising:
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a probe body; a pressure deflectable diaphragm end formed of a conductive material and coupled to the probe body, the conductive material having a first coefficient of thermal expansion, the pressure deflectable diaphragm end having a first surface defining at least a first portion of a capacitor; an alumina disk having a second coefficient of thermal expansion that is less than the first coefficient of thermal expansion, the disk including a metallization layer, with the metallization layer being spaced from the first surface such that the metallization layer at least partially defines a second portion of the capacitor; a spring disposed between the probe body and the alumina disc, the spring biasing the alumina disk toward the pressure deflectable diaphragm end; and an annular shim component disposed at a peripheral region of the alumina disk and isolating the alumina disk from the pressure deflectable diaphragm end, the annular shim being formed of a third material having a third coefficient of thermal expansion; wherein the third coefficient of thermal expansion is less than the first coefficient of thermal expansion.
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- 21. A pressure sensor comprising an intermediate circuit that produces an electrical voltage signal proportional to a difference between a reference capacitance and a sensed capacitance.
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36. A pressure sensor comprising:
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a probe assembly including; a relatively rigid body; a distal end having a capacitive pressure sensor, the capacitive pressure sensor capable of producing a sensed capacitance as a result of pressure acting on the capacitive pressure sensor; and a proximal end opposite the distal end; an intermediate circuit enclosure disposed at the proximal end; a capacitive detection bridge circuit housed within the intermediate circuit enclosure, the capacitive detection bridge circuit producing an electrical voltage signal proportional to a difference between a reference capacitance and the sensed capacitive signal; a remote circuit enclosure; a relatively flexible interconnect coupling the remote circuit enclosure to the intermediate circuit enclosure; and a main circuit disposed in the remote circuit enclosure, the remote circuit enclosure connected to the intermediate circuit enclosure by the relatively flexible interconnect, the capacitive detection bridge circuit transmitting the electrical voltage signal to the main electrical circuit through the interconnect.
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Specification