1224results about "Fluid pressure measurement using capacitance variation" patented technology

The disclosed pressure transducer assembly includes a housing, a pressure sensor disposed within the housing, a coupling establishing a sealed pathway between the housing and an external source of gas or fluid, and a deposition trap disposed in the pathway. The deposition trap provides a plurality of channels, each of the channels being narrower than the pathway.

A disposable pressure sensor includes a substrate and a pressure diaphragm formed upon the substrate. A sensor coil can be provided, comprising a capacitor and an inductor formed on the substrate and surrounded by the pressure diaphragm. The ferrite core is located proximate to the sensor coil, such that when the pressure diaphragm is exposed to a pressure, the diaphragm moves close to the inductor or the capacitor, thereby resulting in a change in the capacitor or the inductor and an indication of pressure. The capacitor can be implanted as an adjustable, trimmable or variable capacitor. The inductor may also be provided as an adjustable or variable inductor and can include the use of a variable capacitor and a PVDF based piezoelectric transducer. When the PVDF layer is under pressure, it can generate an electric field across the interdigital transducer and transmit a signal thereof through an antenna.

Methods and apparatuses for discriminating between user blowing and drawing (sucking) in an electronic vaporization device. Described herein are electronic aerosol devices and methods of controlling or operating them which can accurately differentiate between blowing and drawing (sucking) through the mouthpiece and adjust the control of the vaporizer accordingly.

The invention relates to a flexible, resilient capacitive sensor suitable for large-scale manufacturing. The sensor comprises a dielectric, an electrically conductive layer on the first side of the dielectric layer, an electrically conductive layer on a second side of the dielectric layer, and a capacitance meter electrically connected to the two conductive layers to detect changes in capacitance upon application of a force to the detector. The conductive layers are configured to determine the position of the applied force. The sensor may be shielded to reduce the effects of outside interference.

Disclosed is a device adapted to measure intraocular pressure comprising: a corneal contact lens having a pressure sensor mounted in a recess or cavity in the contact lens, and wherein the contact lens has a back surface which is formed so as to protrude in a desired portion beyond the profile of the adjacent part of the lens and thus to press against the cornea, which protruding portion experiences a reactive deformation which is detected directly or indirectly by the pressure sensor.

A pressure-sensitive capacitive sensor includes a sensing unit in which a plurality of column wires and a plurality of row wires are formed in a matrix, a detecting signal generator, and filters. Capacitances at intersections between the column wires and the row wires change in accordance with externally applied pressure. The detecting signal generator sequentially outputs pulse signals of a predetermined frequency to the column wires of the sensing unit. The filters are connected to the respective row wires of the sensing unit and extract amplitudes of signals of the predetermined frequency. The amplitude is proportional to the capacitance at the intersection.

A capacitive sensor including a housing having a hermetically sealed cavity, a plate in the cavity, a diaphragm forming a part of the cavity and spaced from the plate, a conductive layer on the first diaphragm, and a second conductive layer on the plate, the first and second conductive layers being the electrodes of a capacitor whose capacitance varies with the position of the diaphragm relative to the plate.

By sealing a diaphragm with less processes and lower cost and reducing deformation due to remaining stress, a stable and highly reliable pressure sensor construction is proposed. The pressure sensor is low in measurement error and small in floating capacitance and leakage current and good in characteristic. As a means to attain the above object, a polycrystalline silicon diaphragm is sealed with a silicon oxide film deposited through a LPCVD method and then completely covered. The diaphragm is placed on a surface of a semiconductor substrate with a nearly constant gap of 0.15 to 1.3 μm, and has difference-in-grade constructions of a deformation reducing means due to remaining stress.

At least one pair of capacitively coupled electrodes contained in a structure is used to sense the deflection of a diaphragm in a pressure or force sensor for measuring the pressure or force exerted on the diaphragm. Preferably the structure has properties (such as one or more of the following: dimensions, hardness, area and flexibility) that are substantially the same as those of a real substrate, such as a semiconductor wafer or flat panel display panel.

A physical quantity sensor for detecting a physical quantity includes: a first substrate having a first physical quantity detection element; a second substrate having a second physical quantity detection element, wherein the second substrate contacts the first substrate; and an accommodation space disposed between the first substrate and the second substrate. The first physical quantity detection element is disposed in the accommodation space. The first physical quantity detection element is protected with the first substrate and the second substrate since the first physical quantity detection element is sealed in the accommodation space.

A capacitive vacuum measuring cell has a first housing body and a membrane, both of Al₂O₃ ceramic or sapphire. The membrane is planar with a peripheral edge joined by a first seal to the first housing body to form a reference vacuum chamber. A second housing body of Al₂O₃ ceramic or sapphire opposite the membrane, is joined to the peripheral edge of the membrane by a second seal to form a measurement vacuum chamber. A port connects the vacuum measuring cell to a medium to be measured. At least in the central area of the first housing body, an optical transparent window is formed and at least the central region of the membrane has an optically reflective surface. Outside the reference vacuum chamber, in opposition to and at a distance from the window, an optical fibre is arranged for feeding in and out light onto the surface of the membrane.

A microelectromechanical device and method of fabricating the same, including a layer of patterned and deposited metal or mechanical-quality, doped polysilicon inserted between the appropriate device element layers, which provides a conductive layer to prevent the microelectromechanical device's output from drifting. The conductive layer may encapsulate of the device's sensing or active elements, or may selectively cover only certain of the device's elements. Further, coupling the metal or mechanical-quality, doped polysilicon to the same voltage source as the device's substrate contact may place the conductive layer at the voltage of the substrate, which may function as a Faraday shield, attracting undesired, migrating ions from interfering with the output of the device.

A pressure sensor (30) for harsh environments such as vehicle tires, formed from a chamber (58) partially defined by a flexible membrane (50), the chamber (58) containing a fluid at a reference pressure. In use, the flexible membrane (50) deflects due to pressure differentials between the reference pressure and the fluid pressure, the membrane being at least partially formed from conductive material. A conductive layer (36) is deposited within the chamber (58) spaced from the flexible membrane (50) such that they form opposing electrodes of a capacitor. Associated circuitry (34) is also deposited for converting the deflection of the flexible membrane (50) into an output signal indicative of the fluid pressure. The conductive layer (36) is less than 50 microns from the membrane in its undeflected state because capacitative sensors with closely spaced electrodes can have small surface area electrodes while maintaining enough capacitance for the required operating range. Furthermore, small electrodes reduce the power consumption of the sensor which in turn reduces the battery size needed for the operational life of the sensor.