Abstract: A pressure sensor (30) for sensing fluid pressure in harsh environments such as the air pressure in a tire by providing a chamber (58) partially defined by a flexible membrane (50). The flexible membrane (50) is at least partially formed from conductive material, and the chamber (58) contains a fluid at a reference pressure. The flexible membrane (50) deflects from any pressure difference between the reference pressure and the fluid pressure. A conductive layer (36) within the chamber spaced from the flexible membrane (50) and, associated circuitry (34) incorporating the flexible membrane (50) and the conductive layer (36). The conductive layer (36) and the flexible membrane (50) form capacitor electrodes and the deflection of the flexible membrane (50) changes the capacitance which the associated circuitry (34) converts into an output signal indicative of the fluid pressure.

Abstract: According to the present invention, there is provided a high-precision differential pressure sensor which is not affected by a considerable change in baseline pressure. A differential pressure sensor of the present invention includes: a pair of diaphragms, each including a diaphragm portion capable of being deformed due to application of a pressure and a support portion for holding an outer peripheral edge of the diaphragm portion; a pair of fixed electrodes in disk-like form fixed to the support portions of the diaphragms; and a movable electrode including a disk-like electrode portion and shaft-like projections extending in opposite directions from a central portion of the electrode portion. The shaft-like projections extend at a right angle relative to the electrode portion, and the movable electrode is secured to central portions of the diaphragms through the shaft-like projections so that the electrode portion faces each of the fixed electrodes in a predetermined spaced relationship.

Abstract: The disclosed pressure sensor includes a body, a diaphragm, and a flow defining structure. The body defines an interior volume. The diaphragm divides the interior volume into a first portion and a second portion. At least a first part of the diaphragm moves in a first direction when a pressure in the first portion increases relative to a pressure in the second portion. The first part of the diaphragm moves in a second direction when the pressure in the first portion decreases relative to the pressure in the second portion. The first part of the diaphragm and at least a first part of the body are characterized by a capacitance. The capacitance changes in response to movement of the first part of diaphragm relative to the first part of the body. The flow defining structure provides a fluid flow path from the first portion of the interior volume to a position outside of the internal volume. At least part of the fluid flow path extends from a first location to a second location.

Abstract: A pressure sensing device (10, 40) is shown having a ceramic capacitive sensing element (12) received in a chamber formed in a hexport housing (16). The hexport housing has a fluid passageway (16c) communicating with a recessed chamber (16d) formed in a bottom wall circumscribed by an annular platform shoulder (16e). A thin flexible metal diaphragm (18) is hermetically attached to the bottom wall along the platform shoulder. A curable adhesive resin having a thermal coefficient of expansion and modulus of elasticity appropriately matching that of sensing element (12), such as polyurethane, is cast between the sensing element (12) and the metal diaphragm (18) forming, when cured, a layer bonded to both members resulting in a sensor that is effective in monitoring negative as well as positive fluid pressures.

Abstract: A thin-film resistor (5) provided on a strain-generating part (2) via an insulating film (4) and an electrode thin-film (6) including an electrode pad (10) arranged in the thin-film resistor (5) are provided. The thin-film resistor (5) includes a strain-detecting thin-film resistive part (8) and an electrode connection (9) connected to the resistive part (8). The electrode connection (9) is formed to extend to the electrode pad (10). The electrode pad (10) includes an external-connection bonding area (12) and a testing probe area (13) formed at different positions. The electrode pad (10) is disposed on a tubular rigid body (1) provided at the outer peripheral edge of a strain-generating part (2).

Abstract: A capacitive pressure sensor made up of two silicon on insulator (SOI) wafers lying opposite of each other and joined to each other in a vacuum-tight manner, a recess being formed between the two wafers. The first wafer exclusively supports the evaluation circuits required for measuring the applied pressure and a capacitive electrode, and the second wafer has a recess formed by surface micromechanics processes, in which the counter electrode to the capacitive electrode of the first wafer is situated. The second wafer at the same time forms a cover for the first wafer.

Abstract: A micro-mechanical pressure transducer is disclosed in which a capacitive transducer structure is integrated with an inductor coil to form a LC tank circuit, resonance frequency of which may be detected remotely by imposing an electromagnetic field on the transducer. The capacitive transducer structure comprises a conductive movable diaphragm, a fixed counter electrode, and a predetermined air gap between said diaphragm and electrode. The diaphragm deflects in response to an applied pressure differential, leading to a change of capacitance in the structure and hence a shift of resonance frequency of the LC tank circuit. The resonance frequency of the LC circuit can be remotely detected by measuring and determining the corresponding peak in electromagnetic impedance of the transducer.

Abstract: A wireless pressure sensor system has a pressure sensing capacitor and an inductor mounted on a common housing. The pressure sensing capacitor has a conductive diaphragm, a dielectric layer and a fixed electrode separated at least in part from the diaphragm by a gap formed in the housing. The electrode is arranged with a protrusion such that displacement of the diaphragm varies the area of capacitive contact with the electrode by rolling along the protrusion. The inductor coil and pressure sensing capacitor are connected to form a passive inductive-capacitive (LC) tank circuit. A remote interrogation circuit, inductively coupled to the pressure sensor inductor coil can be utilized to detect the resonant frequency of the LC tank which varies as a function of pressure sensed by the diaphragm.

Abstract: A pressure-measuring device is configured for use in vacuum systems, which are used for surface coating or modification of objects and/or substrates in an inner receptacle inside a processing chamber. Elastic elements or portions are fabricated in the inner receptacle. The pressure-measuring device includes distance-measuring elements designed to measure the deformation of the elastic elements of the inner receptacle. The deformation measurements are related to the pressure in the inner receptacle. The pressure-measuring device provides a continuous and secure determination of the pressure.

Abstract: A pressure sensor includes a case having a concave portion, a sensing portion disposed in the concave portion to output an electrical signal proportional to an applied pressure, a circuit portion disposed in the concave portion and connected to the sensing portion and a conductive diaphragm fixed to the case to cover the concave portion. A conductive member surrounds the sensing portion and the circuit portion to provide an electrical shield. The diaphragm is used as a part of the conductive member.

Abstract: A capacitive load cell includes upper and lower capacitor plates and an intermediate array of dielectric pads formed of silicone-impregnated open-cell urethane foam (i.e., gel pads). The silicone essentially displaces air that would otherwise be trapped in the foam, contributing to a dielectric having minimal humidity-related variability. The upper capacitor plate is defined by an array of individual charge plates, the lower capacitor plate defines a ground plane conductor common to each of the charge plates, and the dielectric pads are disposed between the ground plane conductor and each of the charge plates, leaving channels between adjacent dielectric pads. When occupant weight is applied to the seat, the dielectric pads transmitting the weight distend laterally into the channels to reduce the separation between the respective upper and lower capacitor plates, and the consequent change in capacitance is detected as a measure of the applied force and the force distribution.

Abstract: The present invention provides a highly corrosion-resistant diaphragm pressure sensor capable of obviating the effects of temperature drift that arises when a pressure-travel coefficient changes with temperature of a fluid whose pressure is sensed, and a method of manufacturing the same. A fluororesin thin film diaphragm pressure sensor comprises a pressure sensing element (10, 20) having a pressure receiving part with a deposition electrode formed on each of the opposing faces of sapphire or alumina ceramic diaphragms which are arranged in opposing relation, and a welding portion (10A, 20A) on a part of each of the surfaces of the diaphragms; and a fluororesin base (41, 61) for securing the pressure sensing element at the welding portion of the pressure sensing element. The pressure sensing element is coated with a fluororesin thin film having a cross-linked structure, and the pressure sensing element and the fluororesin base are welded together via the fluororesin thin film having a cross-linked structure.

Abstract: A micromachined capacitive acoustic transducer including an electrode formed by a perforated plate and another electrode formed by a shallowly corrugated membrane anchored at one or more positions on the substrate which also supports the said perforated plate is described. Also disclosed includes: a fixed perforated plate; a movable shallowly corrugated membrane having holes to form acoustic filter to a certain frequency or a range of frequencies spaced from the perforated plate that is anchored in one or more location but loose at other locations; a support structure in the perforated plate maintaining the minimum separation between the membrane and the perforated plate near the perimeter.

Abstract: A capacitive-type sensor comprises a glass plate having an electrode formed thereon, and a micromachined structure formed from a semiconductor material and having an insulating rim formed thereon. A conducting seal is formed on the insulating rim and arranged to be bonded to the glass substrate to define an enclosed cavity containing the electrode, to thereby define a capacitive element, the conducting seal being arranged, in use, to have an electrical signal passed there through to determine a capacitance thereof which is indicative of the parameter to be determined by the sensor.

Abstract: 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.

Abstract: A capacitive vacuum measuring cell includes first and second ceramic housing bodies (1, 4) joined by an edge seal (3). A thin ceramic membrane (2) is supported between first and second housing bodies (1, 4) by the edge seal (3) at a small distance from the first housing body (1) creating a reference vacuum chamber (25) therebetween. An electrically conductive material (7) coats opposing surfaces of the first housing body (1) and the membrane (2) to form a capacitor. A measurement vacuum chamber (26) is provided between the membrane (2) and the second housing body (4). A port (5) communicates with the second housing body (4) to connect the measurement vacuum chamber (26) of the measuring cell to the medium to be measured. The membrane (2) is made from an Al2O3 slurry that is sintered in a first heating step, cooled, and then reheated to smooth the membrane.

Abstract: The present invention is directed at methods and apparatuses for facilitating the establishment of a reference pressure within a reference chamber of a pressure transducer. The transducer has a housing and a cover, the housing defining a reference chamber and an aperture. A meltable sealing material is disposed on at least one of the cover and the housing. The apparatus includes a pressure chamber that is rotatable between a first position and a second position, a pressure source that is connected to the pressure chamber, a guide that is attachable to the transducer near the aperture, and a heater for selectively heating the pressure chamber to a temperature sufficiently high to melt the sealing material. The cover is positioned in an internal space of the guide. The guide is attached to the transducer near the aperture.

Abstract: A pressure sensor includes a silicon-on-insulator (SOI) substrate, a glass substrate bonded to the SOI substrate by anode bonding, a silicon island formed on a part of a silicon layer of the SOI substrate and surrounded by a groove extending to an insulating layer of the SOI substrate, a through hole formed in the glass substrate, and an output electrode that is made of a conductive material, is disposed inside the through hole, and is electrically connected to an electrode formed on the glass substrate via the silicon island.

Abstract: A pressure transmitter for transfer of a pressure prevailing in a first medium onto a second medium, including a pressure chamber 4 in a platform 1, which chamber is separated from the first medium by means of a dividing membrane 2, wherein the pressure can be transferred by means of the second medium to a pressure measurement cell. For timely recognition of an impending failure of the dividing membrane, an early warning detector is provided with a sensor chamber 6 having an opening, which faces the first medium; and a sensor 7, which monitors a property of a medium container in the sensor chamber; and a barrier facing the first medium, pressure-tightly sealing the opening, and which, under contact with the first medium and equal conditions as experienced by the dividing membrane 2, fails earlier than the dividing membrane, thus making possible a flow connection between the sensor chamber 6 and the first medium.

Abstract: A pressure sensor for sensing a fluid pressure in harsh environments such as the air pressure in a tire, by using a chamber partially defined by a flexible membrane (20), the chamber containing a fluid at a reference pressure, such that the flexible membrane (20) deflects due to pressure differentials between the reference pressure and the fluid pressure; and, associated circuitry for converting the deflection of the flexible membrane (20) into an output signal indicative of the fluid pressure; wherein, the membrane (20) is non-planar (22, 24). It is possible to extend the linear range of the pressure-deflection response with a non-planar membrane (20). Corrugations, a series of raised annuli (22) or other surface features are an added complexity in the fabrication process but can extend the linear range of the sensor by 1 MPa.

Abstract: A capacitive pressure transmitter is provided. In one aspect, the transmitter includes a capacitive pressure sensor coupled directly to the measured media without any intervening fluid isolation. A filter is preferably used to keep particulates from reaching the measuring diaphragm. In another aspect, a capacitive pressure transmitter is provided with at least one self-contained isolator interposed between a process connection and the capacitive pressure sensor. In both aspects, the capacitive pressure transmitter is relatively small and preferably constructed from materials that facilitate low-cost manufacture.

Abstract: A pressure sensor (30) for sensing fluid pressure in harsh environments such as the air pressure in a tire by providing a chamber (58) partially defined by a flexible membrane (50). The flexible membrane (50) is at least partially formed from conductive material, and the chamber (58) contains a fluid at a reference pressure. The flexible membrane (50) deflects from any pressure difference between the reference pressure and the fluid pressure. A conductive layer (36) within the chamber spaced from the flexible membrane (50) and, associated circuitry (34) incorporating the flexible membrane (50) and the conductive layer (36). The conductive layer (36) and the flexible membrane (50) form capacitor electrodes and the deflection of the flexible membrane (50) changes the capacitance which the associated circuitry (34) converts into an output signal indicative of the fluid pressure.

Abstract: A ceramic membrane for a capacitive vacuum measuring cell includes a thin ceramic membrane with a thickness of <250 ?m, in particular less than 120 ?m. The membrane is produced from a ribbon-shaped green body of Al2O3, and is given high planarity by smoothing the membrane after sintering. The green body is sintered at a sintering temperature that is higher than the smoothing temperature applied following sintering.

Abstract: A pressure sensor for measuring a pressure of a process fluid includes a vessel, an electrode and a diaphragm. The vessel receives the process fluid. The electrode is integral with an inner wall of the vessel. The diaphragm extends at least partially over the electrode and is configured to move relative to the electrode in response to the pressure of the process fluid. An electrical capacitance between the electrode and the diaphragm is related to the pressure of the process fluid.

Abstract: A transducer includes a substrate and a thin membrane having a shape that can be deflected relative to the substrate to provide an amount of membrane deflection useful for sensing or actuation purposes.

Abstract: A variable capacitance measuring device can comprise a glass-ceramic insulator having a coefficient of thermal expansion that closely matches the coefficient of thermal expansion of a metallic materials used within the device. The glass-ceramic material may chemically bond to the surfaces of the metallic materials to provide a hermetic seal and eliminate the need for a separate glass seal or grooves within the electrode assembly. Additionally, a single-piece electrode assembly can be used instead of a separate electrode assembly (for the electrical feedthrough) and electrode. A shim may be used during the formation of the insulating material to reduce the likelihood of the insulator adhering to surfaces of the electrode portion during the manufacturing process. Also, separate bake-out and getter activation cycles may be combined into a single heat cycle.

Abstract: A sensor includes a sensor main body, first and second electrodes, an electrode extraction hole, and an interconnection member. A cavity is formed in the sensor main body by joining the outer peripheral portions of the first and second substrates made of an insulating material. The first and second electrodes are formed on the inner surfaces of the first and second substrates which face each other through the cavity. The electrode extraction hole is formed through the first substrate in correspondence with the second electrode. The interconnection member guides the second electrode outside the first substrate through the cavity and the electrode extraction hole. The interconnection member is formed by thermal spraying of metal powder into the cavity from outside the sensor main body through the electrode extraction hole. An electrode extraction structure and electrode extraction method are also disclosed.

Abstract: A force or pressure transducer is disclosed. In one embodiment, the transducer has a substrate, a dielectric material disposed on the substrate, a spacing member disposed on the dielectric material, and a resilient element disposed on the dielectric material and the spacing member. A portion of the resilient element is separated from the dielectric material, and a portion of the resilient element is in contact with the dielectric material. The contact area between the resilient element and the dielectric material varies in response to movement of the resilient element. Changes in the contact area alter the capacitance of the transducer, which can be measured by circuit means.

Abstract: A capacitive sensor device for measuring properties of a medium to be measured when this medium surrounds and flows past the sensor. The sensor has a housing of metal, an opening in the housing transverse to the flow of said medium to be measured which is adapted to house at least one capacitive electrode, and where the electrode(s) of the sensor is/are electrically insulated from said medium to be measured by means of a glass ceramic material that is arranged to be flush with the outer surface of the sensor.

Abstract: A pressure sensor system involves a semi-conductive diaphragm electrode overlying a cavity in a semiconductor chip, with the center of the diaphragm secured to a mesa extending upwardly from the cavity. A second electrode is implemented by a heavily doped raised ring between the mesa and the periphery of the chip at the ring of maximum deflection of the diaphragm. The raised ring electrode is heavily doped with one polarity, with light doping near the base of the raised area, and the remainder of the cavity is heavily doped with the opposite polarity. The plot of Linearity Error versus width of the ring electrode, has a minimum, and the width of the ring electrode and related constructional features are selected to conform to the minimum point of the linearity function. The reference capacitor is arcuate in configuration and extends part way around and in immediate proximity to the sensor diaphragm.

Abstract: A micro-mechanical pressure transducer is disclosed in which a capacitive transducer structure is integrated with an inductor coil to form a LC tank circuit, resonance frequency of which may be detected remotely by imposing an electromagnetic field on the transducer. The capacitive transducer structure comprises a conductive movable diaphragm, a fixed counter electrode, and a predetermined air gap between said diaphragm and electrode. The diaphragm deflects in response to an applied pressure differential, leading to a change of capacitance in the structure and hence a shift of resonance frequency of the LC tank circuit. The resonance frequency of the LC circuit can be remotely detected by measuring and determining the corresponding peak in electromagnetic impedance of the transducer.

Abstract: A micro-mechanical pressure transducer is disclosed in which a capacitive transducer structure is integrated with an inductor coil to form a LC tank circuit, resonance frequency of which may be detected remotely by imposing an electromagnetic field on the transducer. The capacitive transducer structure comprises a conductive movable diaphragm, a fixed counter electrode, and a predetermined air gap between said diaphragm and electrode. The diaphragm deflects in response to an applied pressure differential, leading to a change of capacitance in the structure and hence a shift of resonance frequency of the LC tank circuit. The resonance frequency of the LC circuit can be remotely detected by measuring and determining the corresponding peak in electromagnetic impedance of the transducer.

Abstract: A differential pressure sensor for use in an industrial application is described. The differential pressure sensor includes a membrane layer having a covered portion and an exposed portion where a first side of the exposed portion of the membrane layer is in fluid communication to a first aperture and a second side of the exposed portion is in fluid communication to a second aperture. The differential pressure sensor also includes at least one resonating device secured to the covered portion of the membrane layer and configured to oscillate at a desired frequency and a sensing circuitry configured to a detect oscillation in the at least one resonating device indicative of deformation in the membrane layer.

Abstract: The gauge comprises concentric inner and outer tubes made of insulating material, with two capacitors each constituted by a set of electrodes, each set having at least one pair of two electrodes in strip form extending along the gauge and placed facing each other on the facing walls of the inner and outer tubes.

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 load cell apparatus includes upper and lower capacitor plates and an intermediate dielectric in the form of a synthetic knit spacer material having upper and lower fabric layers interconnected by an array of deflectable synthetic fibers. When occupant weight is applied to the seat, the synthetic fibers deflect to locally reduce the separation between the upper and lower capacitor plates, and the consequent change in capacitance is detected as a measure of the applied weight. The load cell or just the dielectric may be encased in a polymeric sheath to prevent intrusion of foreign matter, and a fluid such as silicone may be dispersed in woven dielectric.

Abstract: The disclosed transducer includes a housing, a diaphragm, an inner conductor, an outer conductor, and a first baffle. The housing defines an interior volume. The diaphragm is disposed in the housing and divides the interior volume into a first chamber and a second chamber. The diaphragm flexes in response to pressure differentials in the first and second chambers. The inner conductor is disposed in the first chamber. The outer conductor is disposed in the first chamber around the inner conductor. The first baffle is disposed in the second chamber and defines an inner region, a middle region, and an outer region. The inner region underlies the inner conductor. The middle region underlies the outer conductor. The outer region underlies neither the inner conductor nor the outer conductor. The first baffle defines apertures in at least two of the inner, middle, and outer regions.

Abstract: A semiconductor component for a semiconductor substrate, in which a first section and a second section are provided, and in which the pore structure of the first section differs from the pore structure of the second section.

Abstract: 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.

Abstract: 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.

Abstract: A capacitive pressure sensor and its manufacturing method can simplify the alignment and the bonding process in a vacuum, and stably carry out the bonding process. The capacitive pressure sensor includes an insulating, first substrate with a capacitance electrode, a second substrate which has a diaphragm electrode so as to separate a vacuum chamber and a pressure-measuring chamber on respective surfaces, and an insulating, third substrate with a gas inlet. The substrates are bonded in a manner that the capacitance electrode faces the diaphragm electrode and the pressure-measuring chamber leads to the gas inlet. In addition, a getter chamber is formed in the same surface of the second substrate as the pressure-measuring chamber, and the getter chamber is connected to the vacuum chamber.

Abstract: A Capacitive Micromachined Ultrasonic RF (CMURF) pressure sensor is described. This micromachined pressure sensor has: pressure sensitive capacitance elements including a scalable array of micromachined cells of the type including electrodes carried by a sealed membrane supported above a common electrode with conductive lines interconnecting the electrodes having an electrostatic capacitance ?Cm changing with a pressure to be detected; reference capacitance elements including a scalable array of micromachined cells of the type including electrodes carried by a stacked of membranes supported above a common electrode with conductive lines interconnecting the electrodes having an electrostatic capacitance Cm not changing with the pressure. A method of operating a pressure sensor array is also described.

Abstract: An electronic pressure-sensing device is isolated from corrosive, conductive gasses and fluids by a corrosion resistant metal diaphragm welded to a pressure port. The pressure-sensing device is attached to a support structure with a hole that provides a path from the diaphragm area to the pressure-sensing device. A fill fluid is sealed behind the diaphragm and fills the hole through the support structure to the electronic pressure-sensing device. In this design, any hostile chemical applied is completely isolated from the electronic sensor and associated adhesive seals by the metal diaphragm.

Abstract: A capacitive vacuum sensor includes an elastic diaphragm electrode and a rigid fixed electrode opposite the elastic diaphragm electrode. An internal space is defined between the elastic diaphragm electrode and the rigid fixed electrode. The elastic diaphragm electrode deflects elastically in response to any change in the pressure of a gas applied on the elastic diaphragm electrode, and the capacitive vacuum sensor is responsive to any change in the capacitance between the elastic diaphragm electrode and the rigid fixed electrode that may occur in accordance with the deflection of the elastic diaphragm electrode so that it can measure the pressure of the gas. The vacuum sensor can include an anticorrosive diaphragm electrode that can resist the corrosive action of the reactive gas when it is exposed to such gas, and can be fabricated by the micromachining technology.

Abstract: A capacitive pressure sensor structure, in particular for measurement of absolute pressure, and a method for manufacturing the sensor. The sensor includes at least one fixed electrode, and at least one movable electrode electrically isolated from said fixed electrode and spaced apart from said fixed electrode. A portion of said movable electrode is formed from a porous polycrystalline silicon layer that in a finished component remains as an integral portion of said flexibly movable electrode.

Abstract: In a differential pressure sensor, the measurement value is corrected with the help of the nominal pressure NP. In this way, influences on the measurement value because of deformations of the body of the differential pressure sensor and change in the material stiffness of the membrane are decreased.

Abstract: A pressure sensor includes a capacitive pressure sensor chip mounted with the intervention of a sealing member on a base adaptor so as to be detachable. The sensor chip being constructed in a manner that a second substrate with a diaphragm electrode is placed between a first substrate with a fixed electrode and a third substrate with a pressure inlet and is bonded to the first and the third substrate so as to overlap the fixed electrode, the diaphragm electrode and the pressure inlet with a prescribed gap between the fixed electrode and the diaphragm electrode. Moreover, the third substrate is larger than the second substrate to make place which extends outside the second substrate and plays a role as a sealing surface to be in contact with the sealing member, and the sealing surface is pressed to the base adaptor with the intervention of the sealing member.

Abstract: Systems and methods for digitally controlling sensors. In one embodiment, a digital controller for a capacitance diaphragm gauge is embedded in a digital signal processor (DSP). The controller receives digitized input from a sensor AFE via a variable gain module, a zero offset module and an analog-to-digital converter. The controller automatically calibrates the received input by adjusting the variable gain and zero offset modules. The controller also monitors and adjusts a heater assembly to maintain an appropriate temperature at the sensor. The controller utilizes a kernel module that allocates processing resources to the various tasks of a gauge controller module. The kernel module repetitively executes iterations of a loop, wherein in each iteration, all of a set of high priority tasks are performed and one of a set of lower priority tasks are performed. The controller module thereby provides sensor measurement output at precisely periodic intervals, while performing ancillary functions as well.

Abstract: A cover plate (130) which is a plate member made of sapphire is joined to a pressure sensor chip (110), to which a buffer member (120) is fixed, by using a coating solution prepared by adding titanium dioxide to an aqueous solution of boehmite (AlO(OH)) which is a hydroxymineral of aluminum.

Abstract: A capacitive manometer includes a flow passage through which gas can enter the manometer, a deflectable diaphragm, and a filter arranged in the flow passage. The filter is capable of removing condensable vapors from the gas so that the condensable vapors do not reach and deposit on the diaphragm. The capacitive manometer can include a cooling unit arranged to cool the filter so as to enhance removal of condensable vapors from the gas by the filter. The capacitive manometer can include a baffle having gas passages distributed to control distribution of condensable vapors, which pass through the baffle, on the diaphragm.