Abstract: A method and apparatus integrates differential pressure measurements and absolute pressure measurements to provide a continuous absolute pressure profile over a wide range of pressures on a single integrated scale. The absolute pressure measurements and differential pressure measurements are obtained, and a correlation factor between the absolute pressure measurements and the differential pressure measurements is determined. The correlation factor is used to normalize the differential pressure measurements to virtual absolute pressure values on a common absolute pressure scale with the absolute pressure measurements. An absolute pressure profile over a wide pressure range includes the absolute pressure measurements in a portion of the range where the absolute pressure measurements are accurate, and it includes the virtual absolute pressure values in another portion of the range where the differential pressure measurements are accurate.

Abstract: A pressure-sensor package mainly includes a pressure sensor, a support substrate, and a resin layer. The pressure sensor includes a glass substrate having a fixed electrode, and a silicon substrate having a diaphragm that is disposed apart from the fixed electrode by a predetermined distance. The support substrate is a silicon/glass composite substrate on which the pressure sensor is mounted such that the support substrate and the diaphragm face each other. The resin layer fixes the pressure sensor and the support substrate together. The pressure sensor is mounted on a mounting area of the support substrate with a joint member therebetween. Accordingly, even if a gap between the support substrate and the diaphragm has a size of about several micrometers, the pressure-sensor package is capable of performing pressure detection with high sensitivity.

Abstract: The invention provides for a method of sensing pressure with a pressure sensor having a sensor membrane and a compensation membrane. The pressure sensor also includes a power supply, a controller; and a charge amplifier, a charge injector and two switches arranged in signal communication with the controller. The method includes the step of connecting the charge amplifier to the switches via a sensor capacitor Cs in parallel with a reference capacitor Cr in parallel with a parasitic capacitance Cp to ground, the charge injector and charge amplifier arranged in parallel connection between the capacitors and the controller. The method also includes the step of operating the switches, via the controller, to determine a charge imbalance indicative of a pressure difference between the sensor and compensation membranes.

Abstract: Provided is a temperature compensating pressure sensor. The sensor includes a silicon substrate having sealed channels on which is deposited a CMOS layer, and a conductive layer and a passivation layer deposited on the CMOS layer, the conductive layer representing a first electrode. The sensor also includes a conductive active membrane spaced from the conductive layer to form an active chamber, and a conductive reference membrane spaced from the conductive layer to form a sealed reference chamber. Also included is a cap which covers the membranes, said cap having a channel to expose the active membrane to an outside fluid pressure, with the membranes representing a second electrode. The active membrane deflects due to differential stresses so that the first and second electrodes develop a capacitance C between them depending on the electrical permittivity of the fluid, with the reference membrane providing a temperature compensating reference capacitance.

Abstract: A capacitive pressure sensor includes a substrate assembly. The substrate assembly includes a conductive layer and defines a plurality of channels terminating in closed ends. A conductive membrane is mounted to the substrate assembly so that a sealed reference chamber including the channels is defined by the conductive membrane and the substrate assembly. A cap is mounted relative to the substrate assembly and defines one or more apertures so that an antechamber is defined by the cap and the conductive membrane. Differential pressure between the reference chamber and antechamber can cause deflection of the conductive membrane which, in turn, varies the capacitance between the conductive membrane and conductive layer.

Abstract: A device for introducing air or other pressurized gas into a tire, sports ball or other pneumatic device. The device advantageously allows the user to check the pressure of the gas and to release excess the gas from the tire or other pneumatic device without removing the apparatus from the tire or other pneumatic device.

Abstract: A pressure sensor for sensing a fluid pressure in harsh environments such as the air pressure in a tire formed on a wafer substrate. Associated circuitry deposited in CMOS layers on the wafer substrate has a conductive layer at least partially overlying the associated circuitry, the conductive layer forming a first electrode of the capacitative sensor. A conductive membrane at least partially overlies the conductive layer, and is spaced from it to form a second electrode of the capacitative sensor. The conductive membrane separates fluid at a reference pressure and fluid at the pressure to be sensed such that the associated circuitry is configured to convert the deflection of the conductive membrane into an output signal indicative of the fluid pressure. The conductive membrane is at least partially formed from a ceramic material to provide corrosion and wear resistance.

Abstract: A pressure sensor comprises a first pressure chamber containing fill fluid at a first pressure, a second pressure chamber containing fill fluid at a second pressure, a porous dielectric diaphragm having first and second major surfaces exposed to the first and second pressure chambers, and first and second electrodes positioned with respect to the first and second major surfaces. A method for sensing pressure is also disclosed, comprising applying first and second pressures to fill fluid in first and second pressure chambers of a pressure sensor having a porous dielectric diaphragm, and producing an output representative of a pressure differential between the pressures, as a function of surface charges on first and second major surfaces of the porous dielectric diaphragm.

Abstract: A system and method are described for maintaining power dissipation substantially constant across the sensor interface board of a capacitance pressure transducer. A shorted diaphragm level detector detects a shorting of the diaphragm onto one or more reference electrodes. A power dissipating resistor is placed near the oscillator that drives the capacitance detecting circuit in the capacitance pressure transducer. The resistor is switched across a power supply when the shorting is detected, causing current to flow through the resistor so that power can be added in an amount sufficient to maintain power dissipation by the oscillator substantially constant when the diaphragm shorts.

Abstract: A gap-change sensing through capacitive techniques is disclosed. In one embodiment, an apparatus includes a first conductive surface and a second conductive surface substantially parallel to the first conductive surface, and a sensor to generate a measurement based on a change in a distance between the first conductive surface and the second conductive surface. The change in the distance may be caused by a deflection of the first conductive surface with respect to the second conductive surface, and the deflection may be a compressive force and/or an expansive force. The sensor may apply an algorithm that converts a change in capacitance to at least one of a change in voltage and/or a change in frequency to generate the measurement. The change in the distance may be caused by a load applied to the surface above the first conductive surface with respect to the second conductive surface.

Abstract: A diffusion bonded space-conserving integrated fluid delivery system which is particularly useful for gas distribution in semiconductor processing equipment. The disclosure includes an integrated fluid flow network architecture, which may include, in addition to a layered substrate containing fluid flow channels, various fluid handling and monitoring components. A capacitive dual electrode pressure sensor which is integrated into a multilayered substrate is described. The pressure sensor may be used as a gage relative to atmospheric pressure if desired for a particular application.

Abstract: A capacitive pressure sensor and method for its fabrication. The sensor is fabricated from first and second wafers to have a mechanical capacitor comprising a fixed electrode and a moving electrode defined by a conductive plate. The sensor further has a diaphragm on a surface of the first wafer that is mechanically coupled but electrically insulated from the conductive plate. A conductive layer on the surface of the first wafer is spaced apart from the conductive plate to define the fixed electrode. The second wafer is bonded to the first wafer and carries interface circuitry for the sensor, including the conductive plate and the fixed electrode which are between the first and second wafers and electrically connected to the interface circuitry. At least an opening is present in the first wafer and its first conductive layer by which the diaphragm is released and exposed to an environment surrounding the sensor.

Abstract: A capacitive pressure sensor includes a substrate assembly having a conductive layer. A conductive membrane is mounted to the substrate assembly so that a sealed reference chamber is defined by the conductive membrane and the substrate assembly. A cap is arranged on the substrate assembly and defines one or more apertures so that an antechamber is defined between the cap and the conductive membrane. Differential pressure between the reference chamber and antechamber can cause deflection of the conductive membrane which, in turn, varies the capacitance between the conductive membrane and the conductive layer.

Abstract: A capacitive pressure sensor for an industrial process transmitters comprises a housing, a sensing diaphragm, an electrode and a fill fluid. The housing includes an interior cavity and a channel extending from an exterior of the housing to the cavity. The sensing diaphragm is disposed within the interior cavity opposite the electrode. The fill fluid occupies the interior cavity such that a pressure from the channel is conveyed to the sensing diaphragm to adjust a capacitance between the electrode and the sensing diaphragm. The fill fluid has a dielectric constant higher than about 3.5. In various embodiments, the pressure sensor has a diameter less than approximately 3.175 centimeters (˜1.25 inches), the electrode has a diameter less than approximately 1 cm (˜0.4 inches), the pressure sensor has a capacitance of approximately 5 to approximately 10 pico-farads, and the fill fluid is comprised of hydraulic fluid having a liquid additive.

Abstract: A pressure sensor for sensing a pressure of a process fluid includes a sensor body having a cavity formed therein. A deflectable diaphragm is positioned in the cavity and deflects in response to a pressure applied to the cavity. An electrode on the diaphragm forms a variable capacitor with the pressure sensor body. The capacitance varies in response to the applied pressure.

Abstract: A pressure sensor for sensing a fluid pressure in a high acceleration environment. The sensor has a non-planar membrane between fluid at a reference pressure and fluid at the pressure to be sensed, such that the non-planar membrane deflects due to pressure differentials between the reference pressure and the fluid pressure. The deflection is converted into an output signal indicative of the fluid pressure by associated circuitry. By keeping the area of the membrane exposed to the fluid in the chamber to less than 0.1 grams, the acceleration forces have minimal affect on the amount that membrane flexes.

Abstract: A capacitive sensor for measuring pressure comprises a fixed charge plate integral to a printed circuit board, a flexible charge plate that is grounded, a conductive donut-shaped adhesive spacer between the charge plates, a lid, a non-conductive donut-shaped adhesive spacer between the second charge plate and the lid, means of providing a pressure, fixed or variable, to both sides of the flexible charge plate, wherein a microcontroller controls a power supply and provides a voltage to the first charge plate wherein the accumulative voltage may be measured as a means of determining differential pressure.

Abstract: In a capacitance type pressure sensor (1) including capacitance detecting portions formed in opposed regions in a capacitance chamber which is at least partially formed of a diaphragm, the capacitance detecting portions being a pressure-sensitive capacitance detecting portion (101) formed in a region of the diaphragm having large sensitivity with respect to a pressure and a reference capacitance detecting portion (102) formed in a region of the diaphragm having small sensitivity with respect to a pressure, there is provided the capacitance type pressure sensor which is entirely small in size and superior in reliability by independently detecting a signal output value of the reference capacitance detecting portion (102).

Abstract: A capacitive sensor and a method of making it with a substrate having a diaphragm forming a first plate of a capacitor; a second fixed plate of the capacitor spaced from the diaphragm and defining a predetermined dielectric gap; a plurality of conductor elements interconnecting the substrate and fixed plate; and an edge lock supporting the fixed plate and the substrate relative to each other for maintaining the dimension of the defined gap independent of the conductor elements.

Abstract: A microfluidic device and method for capacitive sensing. The device includes a fluid channel including an inlet at a first end and an outlet at a second end, a cavity region coupled to the fluid channel, and a polymer based membrane coupled between the fluid channel and the cavity region. Additionally, the device includes a first capacitor electrode coupled to the membrane, a second capacitor electrode coupled to the cavity region and physically separated from the first capacitor electrode by at least the cavity region, and an electrical power source coupled between the first capacitor electrode and the second capacitor electrode and causing an electric field at least within the cavity region. The polymer based membrane includes a polymer.

Abstract: A variable capacitance measuring device can comprise any one or more features in various different embodiments allow a reliable, compact device to be achieved. A capacitor electrode, a gettering housing, and pinch-off connector may be aligned along a common axis may reduce width dimensions without a substantial increase in length. Temperature-induced variations may be reduced by selecting materials that have coefficients of thermal expansion relatively closer to one another. Substantially varying topologies for ceramic-metal interfaces may reduce the likelihood of external contaminants from reaching the evacuated portion of the device. A tube can be used between the capacitor portion and a gettering housing to isolate external forces and getter activation heat from the sensor. The same tube also reduces heat loss from a heated sensor and protects the electronics from overheating. Embodiments also include processes for using and forming the devices.

Abstract: A capacitive pressure sensor includes a electrically conductive, generally piston shaped diaphragm with a flexible base wall configured to deflect under pressure. The diaphragm is generally U-shaped in cross section. The base wall includes an upper, flat sensing surface which acts as a capacitive electrode. The diaphragm further includes a step around a radially-outermost perimeter which is elevated from the flat sensing surface. A sensing electrode body is located on top of the step and creates a capacitive sensing cavity between the sensing surface and the bottom surface of the electrode body. On the bottom surface of the electrode body is formed a center, circular electrode and a ring electrode that surrounds the center electrode. The center electrode and the sensing surface form a variable capacitor which changes with pressure and the ring electrode and the sensing surface form a reference capacitor.

Abstract: 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.

Abstract: A pressure sensing system formed in a monolithic semiconductor substrate. The pressure sensing system comprises a pressure sensing device formed on the monolithic semiconductor substrate. The pressure sensing device is adapted to be disposed in an environment for developing an electrical pressure signal corresponding to the pressure in the environment. The system includes driver circuitry formed in the monolithic semiconductor substrate. The driver circuitry is responsive to input electrical signal for generating an output pressure signal. A conductive interconnect structure formed in the monolithic semiconductor substrate to electrically connects the pressure sensing device to the driver circuitry such that electrical pressure signals developed by the pressure sensing device are provided as input electrical signals to the driver circuitry.

Abstract: Introduced is a method for the production of a diaphragm vacuum measuring cell, wherein on the one side of the diaphragm (2) at a spacing a first housing plate (1) is disposed sealing in the margin region with a joining means (3), and that on the other side of the diaphragm (2) at a spacing a second housing plate (4) is disposed sealing in the margin region with a joining means (3), and that the second housing plate (4) has an opening at which a connection means (5) is disposed sealing with joining means (3) for the connection of the measuring cell (8) with the medium to be measured, wherein the diaphragm (2) and the two housing plates (1, 4) are comprised of a metal oxide.

Abstract: To accurately set a detection axis of a sensor even when the sensor is attached to an inclined surface, provided is: a sensor responsive to an operation to a predetermined detection axis. A sensor device accommodates this sensor 1 and is a lead provided for conduction between a terminal of this sensor device and a mounting board. A mold for fixing the sensor device to set the detection axis of the sensor and a bottom surface of the mold with a desired angle is also provided.

Abstract: The invention relates to a pressure measuring cell comprising a base body, a membrane that is connected to the base body, thus forming a measuring chamber. During operation, the membrane is subjected to a deflection which is dependent on a pressure that is to be measured. The cell also comprises a membrane bed, formed by a surface of the base body that faces the membrane, at least one electrode being mounted on said bed. Said electrode, together with a counter-electrode that is mounted on the membrane, forms a capacitor, whose capacitance represents a measurement for the deflection of the membrane. The measuring cell is characterized in that the electrode is electrically connected through the base body and that the measuring chamber has a smooth surface in the contact zone, said surface having a contact pin that is guided in a bore through the base body.

Abstract: A pressure actuated switch for a pressure control region includes a diaphragm with a first electrically conductive surface and a second conductive surface electrically isolated from the first conductive surface. The switch also includes an evacuated cavity disposed between the first conductive surface and the second conductive surface and includes a piezoelectric assembly on which is mounted the second conductive surface. A controller applies a control signal to the piezoelectric assembly. The piezoelectric assembly in response to the control signal translates the second conductive surface to set a trip point of the switch. The diaphragm is exposed to the pressure of the pressure control region. In response to the pressure applied to the first conductive surface, the first conductive surface deflects in a direction toward the second conductive surface. The first conductive surface communicates with the second conductive surface to produce a signal when the applied pressure is sufficiently large.

Abstract: 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.

Abstract: A pressure sensor (30) for sensing a fluid pressure in harsh environments such as the air pressure in a tire, by using a chamber (58) partially defined by a flexible membrane (50), the flexible membrane (50) is a laminate having at least two layers wherein at least one of the layers is at least partially formed from conductive material, and the chamber (58) containing a fluid at a reference pressure, such that the flexible membrane (50) deflects from any pressure difference between the reference pressure and the fluid pressure; and, associated circuitry (34) for converting deflection of the flexible membrane (50) into an output signal indicative of the fluid pressure. Forming the membrane from a number of separately deposited layers alleviates internal stress in the membrane (50). The layers can be different materials specifically selected to withstand harsh environments.

Abstract: A pressure sensor is composed of a pressure housing having a pressure chamber inside and a pressure sensitive element arranged in the pressure chamber, and a joint housing having a fluid passage for leading fluid into the pressure housing, wherein the pressure housing and the joint housing are jointed by brazing with an insulating member interposed at a joint section therebetween. A stress relieving member is interposed at least either between the metal housing and the insulating member or between the joint housing and the insulating member, so that the insulating member can be relieved of a stress which is caused by the braze jointing to act on the insulating member.

Abstract: A capacitive pressure sensor and method of manufacturing the same is provided. The capactive pressure sensor includes a glass substrate that has a pair of surfaces opposite to each other. A recessed portion is provided to form a cavity on one of the pair of principal surfaces. A first protruding portion provided in the recessed portion. A first silicon substrate has a fixed electrode formed on the first protruding portion, and a movable electrode disposed with a predetermined interval between the fixed electrode and the movable electrode.

Abstract: A multi-zone capacitive force sensing apparatus/method is disclosed. In one embodiment, an apparatus includes one or more capacitors each having an upper conductive surface and a lower conductive surface substantially parallel to the upper conductive surface, a housing with a top plate and a bottom plate to encompass the capacitors, and a sensor in the housing to generate a measurement based on a change in a distance between the upper conductive surface and the lower conductive surface of each of the capacitors when a contact zone of the top plate associated with the each of the plurality of capacitors is deflected by a force applied on the contact zone. The apparatus may also include a comparison module associated with the sensor to generate a signal indicating unevenness of a force applied on the top plate when there is any significant difference between measurements of the capacitors.

Abstract: A pressure sensor that has a sensor membrane for exposure to fluid at a pressure to be sensed, and a compensation membrane sealed from the fluid at the pressure to be sensed. Associated circuitry connected to the sensor membrane converts deflection into an output signal indicative of the fluid pressure. The circuitry also connects to the compensation membrane to convert deflection into an adjustment to the output signal that compensates for membrane deflection due to thermal expansion.

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.

Abstract: A pressure sensor having a predetermined chamber dome angle with an electrode. A hole is located in the top to provide pressure readings and the bottom has an input port. A primary diaphragm is coated on both sides with an electrode and an insulator. A secondary diaphragm is coated on the side which faces the primary diaphragm. Offset holes are made in the two diaphragms which permits pressure equalization during self calibration. Both diaphragms are initially energized to seal the gage volume, and then the secondary diaphragm is used to self calibrate using a known pressure.

Abstract: A capacitive pressure sensing device comprising, a base member, a diaphragm member deflectable under an external pressure, a cantilever member disposed between the base member and the diaphragm member and supported on a support structure, wherein the base member and the cantilever member form a capacitor structure of the device and wherein deflection of the diaphragm member beyond a threshold value causes the cantilever member to deflect to cause a capacitive change in the capacitor structure.

Abstract: A two phase, second order capacitance-to-digital (CD) modulator includes a first stage sigma-delta integrator that forms charge packets as a function of sensor capacitance during an auto-zero phase and integrates the packets during an integration phase to produce an output voltage. The first stage integrator holds its output voltage during the auto-zero phase, so that a second stage sigma-delta integrator can sample the first stage output voltage during the auto-zero phase and integrate the sampled voltage during the integration phase.

Abstract: A capacitance-to-digital (CD) modulator converts capacitance of a differential pressure sensor to a pulse code modulation output signal. The first stage of the CD modulator is a sigma-delta integrator having an auto-zero capacitor connected between an integrator input node and an amplifier input. During an auto-zero phase, a feedback capacitor is connected between the amplifier input and output, and the auto-zero capacitor stores a voltage that is a function of leakage resistance of the sensor capacitor connected to the integrator input node. During an integration phase, the feedback capacitor is connected to the integrator input node. If an overpressure/short circuit condition exists, the stored voltage on the auto-zero capacitor induces a current to flow to the feedback capacitor to drive the integrator to saturation and suppress foldback anomaly.

Abstract: The axial distance between opposing conductors of a capacitance pressure transducer can depend, in part, upon the thickness of a seal that is disposed between a housing and a diaphragm of the capacitance pressure transducer. The present invention utilizes spacer elements and sealing beads to form a seal that is disposed between the housing and the diaphragm of a capacitance pressure transducer. The sealing beads have a melting temperature that is lower than the melting temperature of the spacer elements. The sealing beads are melted so that they flow around and surround the unmelted spacer elements. Upon solidifying, the sealing beads and the spacer elements thus form the seal. The thickness of the seal can be established accurately and uniformly by controlling the height of the spacer elements.

Abstract: A diagnostic system for a pressure sensor having a cavity configured to receive on applied pressure is provided. The cavity has a first and a second wall. A deflectable diaphragm is positioned in the cavity and configured to form a first and a second capacitance with the first wall and a third and a fourth capacitance with the second wall which change in response to the applied pressure. The capacitances form a first transfer function and a second transfer function. Changes in the first transfer function relative to the second transfer function are detected to provide a diagnostic output.

Abstract: A 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.

Abstract: A circuit that senses a process variable, comprises a voltage divider that includes first and second capacitances. At least one of the capacitances is varied by the process variable. Divider ends receive modulated potentials, and a divider center tap coupled to a detector. The detector has a detector output representing carrier frequency range components. A control circuit controls a baseband envelope of the modulated potentials as a function of the detector output.

Abstract: A diaphragm pressure sensor includes a first insulating substrate, a conductive substrate with a diaphragm, and a second insulating substrate with a gas inlet are bonded so as to form a pressure reference room between the diaphragm and the first insulating substrate and a pressure measuring room between the diaphragm and the second insulating substrate. The deformation of the diaphragm caused by the pressure difference between the pressure measuring room and the pressure reference room is measured to obtain the pressure of a space which is communicated with the pressure measuring room through the gas inlet. Furthermore, a plate is adhered to a surface of at least one of the first and second insulating substrates and the plate has a lower thermal expansion rate in an ambient temperature than that of the insulating substrate to which the plate is adhered.

Abstract: A pressure sensor (30) for harsh environments such as vehicle tires, the sensor having a chamber (58) partially defined by a flexible membrane (50), the chamber 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, so that, associated circuitry (34) can convert the deflection of the flexible membrane (50) into an output signal indicative of the fluid pressure. The sensor is a MEMS device whereby the recess, the flexible membrane and the associated circuitry are formed using lithographically masked etching and deposition techniques. MEMS fabrication techniques can produce the sensor in such high volumes that the unit cost of each sensor is very low. The MEMS sensor is so small that it can be installed in very restricted areas such as the stem of the tire valve.

Abstract: A pressure sensor for sensing a fluid pressure in a high acceleration environment. The sensor has a chamber partially defined by a non-planar membrane, the chamber containing a fluid at a reference pressure, such that the non-planar membrane deflects due to pressure differentials between the reference pressure and the fluid pressure. The deflection is converted into an output signal indicative of the fluid pressure by associated circuitry. By keeping the area of the membrane exposed to the fluid in the chamber to less than 0.1 grams, the acceleration forces have minimal affect on the amount that membrane flexes.

Abstract: The invention relates to measuring devices for the measuring of pressure, and more specifically to capacitive pressure sensors. The silicon crystal planes {111} are located at the corners of a wet etched membrane well of a pressure sensor element according to the present invention. An object of the invention is to provide an improved method of manufacturing a capacitive pressure sensor, and a capacitive pressure sensor suitable for use, in particular, in small capacitive pressure sensor solutions.

Abstract: 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.

Abstract: A microfluidic device and method for capacitive sensing. The device includes a fluid channel including an inlet at a first end and an outlet at a second end, a cavity region coupled to the fluid channel, and a polymer based membrane coupled between the fluid channel and the cavity region. Additionally, the device includes a first capacitor electrode coupled to the membrane, a second capacitor electrode coupled to the cavity region and physically separated from the first capacitor electrode by at least the cavity region, and an electrical power source coupled between the first capacitor electrode and the second capacitor electrode and causing an electric field at least within the cavity region. The polymer based membrane includes a polymer.

Abstract: Disclosed is a pressure measuring system for a vacuum chamber, in particular, a pressure measuring system for a vacuum chamber using ultrasonic wave. In this regard, there is provided a pressure measuring system for a vacuum chamber using ultrasonic wave, comprising a vacuum chamber 10 formed with desired vacuum at the inside thereof; ultrasonic wave-emitting means mounted close to an outer peripheral surface of the vacuum chamber 10 for emitting an ultrasonic wave 62 to the inside of the vacuum chamber 10; ultrasonic wave-receiving means for receiving a reflection wave 64 reflected after the striking of the ultrasonic wave 62 emitted from the ultrasonic wave-emitting means to the vacuum chamber; reflection wave-detecting means for detecting the reflection wave 64 from the ultrasonic wave-receiving means; and amplitude-analyzing means for analyzing the amplitude of the reflection wave 64 detected by the reflection wave-detecting means.