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US 2008/0184787 A1Published application
Temperature and pressure transducer
AssigneeChevron U.S.A. Inc.
InventorDon M. COATES
Life of this patent
Estimating the term…
Abstract
Methods for making and systems employing pressure and temperature sensors are described. Embodiments include a capacitive element including a first conductor plate and a second conductor plate. Each plate includes a conductor layer formed on a substrate. In a pressure sensor embodiment, seal is positioned at or near the edges of the conductor plates, and a gas retained in a gap defined between the plates. In a temperature sensor embodiment, the gap defined between the plates is in fluid communication with the external environment.
Claims31
A system for sensing a characteristic in a subterranean environment, comprising:
- a signal generator, configured and arranged generate an electromagnetic signal;
- a sensor probe, locatable in a region of the subterranean environment, the sensor probe including a resonant circuit portion that includes a capacitive element, the resonant circuit portion being configured and arranged to receive energy from the electromagnetic signal and to generate a ringing signal in response to the electromagnetic signal, wherein the capacitive element of the sensor probe is responsive to a condition of the characteristic in the region of the subterranean environment to modulate the ringing signal in accordance therewith;
- the capacitive element comprising:
- a first conductor plate having a first conductive layer supported by a first substrate;
- and
- a second conductor plate having a second conductive layer supported by a second substrate, the first and second conductor plates together defining an adjustable gap therebetween, the adjustable gap being adjustable responsive to the condition to alter a capacitance of the capacitive element;
- a receiver, configured and arranged to receive the modulated ringing signal;
- and
- a processor, configured and arranged to process the modulated ringing signal to obtain a measurement of the condition.
6 more elements
A capacitive sensor comprising:
- a first conductor plate having a first conductive layer supported by a first substrate;
- a second conductor plate having a second conductive layer supported by a second substrate, the first and second conductor plates together defining an adjustable gap therebetween;
- and
- a seal between the first and second conductor plates, the seal constructed and arranged to retain a compressible material in an adjustable gap between the first and second conductor plates and wherein the adjustable gap is adjustable responsive to a pressure condition to alter the capacitance of the capacitive element and wherein the first and second conductor plates are arranged and comprise materials selected such that a change in the adjustable gap due to a change in temperature is less than a change in the adjustable gap due to a change in pressure.
1 more element
A capacitive sensor comprising:
- a first conductor plate having a first conductive layer supported by a first substrate, the first conductive layer having a higher coefficient of thermal expansion than does the first substrate;
- a second conductor plate having a second conductive layer supported by a second substrate, the second conductive layer having a higher coefficient of thermal expansion than does the second substrate, and the first and second conductor plates together defining an adjustable gap therebetween, wherein the adjustable gap is adjustable responsive to a temperature condition to alter an capacitance of the capacitive element;
- and
- a volume between the first and second conductor plates comprising the adjustable gap being in fluid communication with the subterranean environment.
1 more element
A method of measuring a characteristic in a subterranean environment, comprising:
- generating an electromagnetic signal;
- receiving energy from the electromagnetic signal and generating a ringing signal in response to the electromagnetic signal, using a capacitive element that is responsive to a condition of the characteristic in the region of the subterranean environment to modulate the ringing signal in accordance therewith;
- the capacitive element comprising:
- a first conductor plate having a first conductive layer supported by a first substrate;
- and
- a second conductor plate having a second conductive layer supported by a second substrate, the first and second conductor plates together defining an adjustable gap therebetween, the adjustable gap being adjustable responsive to the condition to alter a capacitance of the capacitive element;
- receiving the modulated ringing signal;
- and
- correlating the modulation with a measurement of the condition.
6 more elements
Dependencies are inferred from the claim text.