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 pressure sensor includes a metal housing and a semiconductor chip. The housing has a diaphragm unitary with the housing and an inlet for introducing fluid to the diaphragm. The inlet has a first end exposed to the diaphragm and a second end exposed to an outside of the housing. The housing has a thin-wall portion at the first end of the inlet and the thin-wall portion serves as the diaphragm. The chip is mounted on the diaphragm. The area and thickness of the chip are set so that separation between the chip and diaphragm can be prevented. Since the separation is prevented based on the area and thickness of the chip, there is no need that the diaphragm is made of a material having a thermal expansion coefficient similar to that of the chip.

Abstract: The invention relates to a force measuring device, especially a pressure gauge (1), comprising a deformation element (2) that can be deformed as a result of an impingement by a force, particularly pressure, and at least one measuring element (4a, 4b) by means of which a deformation of the deformation element (2) can be converted into an electrical test signal. The measuring element (4a, 4b) is disposed on a planar substrate (6) which is attached to the deformation element (2) such that a deformation of the deformation element (2) caused by the impingement by a force also results in the substrate (6) being deformed. The inventive force measuring device is characterized in that the substrate (6) is made of an electrically insulating material while the substrate (6) is provided with less flexural rigidity than the deformation element (2) as a result of the material of which the same is made. Also disclosed is an associated production method.

Abstract: A pneumatic controller for controlling a device.

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 method of making a force sensor, the force sensor being particularly sensitive the axial component of a force applied along a predetermined axis, of the type including a force-receiving membrane deformable by an applied force to be sensed, the method comprising: providing the force sensor with a body of a liquid, and with a second membrane separated from said force-receiving membrane by the body of liquid; applying the force to be sensed to the center of the force-receiving membrane to thereby pressurize the liquid according to the magnitude and axis of the force applied to the force-receiving membrane; and measuring the deformation of the second membrane; wherein the force-receiving membrane is of a non-undulating configuration in its normal condition and is deformable, by a force applied to its center at an oblique angle to its surface, into an undulating configuration, to include an inwardly-bowed section on one side of its center, and an outwardly-bulged section on the opposite side of its center, such

Abstract: A differential pressure sensor includes a case, a first and a second pressure sensing element, a first and a second pressure introduction passage, and a differential pressure determining element. The first and second pressure sensing elements work to respectively sense a first and a second pressure. The first and second pressure introduction passages are provided to respectively introduce the first and second pressures to the first and second pressure sensing elements. The differential pressure determining element works to determine a differential pressure as the difference between the first and second pressures sensed by the first and second sensing elements. The first and second pressure sensing elements have the same shape and size and are symmetrically arranged in the case with respect to a reference. The first and second pressure introduction passages also have the same shape and size and are symmetrically positioned in the case with respect to the reference.

Abstract: A pressure sensor includes a sensing element fabricated on an N-type epitaxial layer grown on a P-type substrate, a P-type isolation region located around the edge of the sensing element die and in contact with the P-type substrate, and a conductive elastomeric seal engaging the P-type isolation region prevents shorting of the conductive elastomeric seal with the N-type epitaxial layer of the sensing element die. A method of making a pressure sensor comprises growing an n-type epitaxy layer on a p-type substrate wafer, resulting in a pressure sensor die and substrate having an edge, obtaining a mask adapted for fabricating an isolation diffusion layer around the edge using P-type material, and creating an isolation layer diffusion using P-type doping material around the edge using the mask. A conductive elastomeric seal can then be placed over the sensor die to make electrical contact to the package.

Abstract: Pressure measurement may be achieved by using a pressure-conveyance media that responds to externally applied pressure to convey pressure to a pressure sensor. With the conveyance of pressure, the pressure measurement may be accomplished by determining a pressure of the pressure-conveyance media, determining a temperature of the pressure-conveyance media, and determining pressure externally exerted on the pressure-conveyance media based one the pressure of the pressure-conveyance media and the temperature of the pressure-conveyance media.

Abstract: A pressure header assembly has a closed front and back surface. The back surface has an aperture for accommodating a separate dual die pressure header. The dual die pressure header has an absolute and differential pressure sensor positioned thereon. A differential pressure port is located on a side surface of the pressure header assembly and is directed to a bore in the pressure header assembly. The bore contains an elongated tube which is positioned in the pressure header assembly and locked in place by means of a crush nut and locking nut assembly. One end of the tube is coupled to the differential pressure port, while the other end of the tube accommodates a differential pressure tube which is bent in an arcuate position and directed to the underside of the sensor of the differential sensor assembly mounted in the dual die pressure header.

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 has one side exposed to the fluid pressure and the conductive layer is sealed from the fluid pressure by the conductive membrane such that, the associated circuitry converts 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 includes a case, terminals, a pressure sensing element, a port, and a temperature sensing element. The terminals are assembled to the case by insert molding and connectable to an external device. The pressure sensing element is electrically connected with the terminals and housed in the case. The port having a pressure receiving hole through which a pressure transmitting medium is led to the pressure sensing element is connected with the case. The temperature sensing element is electrically connected with the terminals and arranged in the pressure receiving hole. A part of each terminal is passed through the pressure receiving hole and extended to the temperature sensing element. The extended part is electrically connected to the temperature sensing element. The extending portion is formed as an insert molding portion of the case and held with a material forming the case.

Abstract: A compliant balloon having an outer reflective surface which is positioned next to a transparent window which has an opaque element thereon, the reflection of the opaque element from the outer reflective surface of the balloon being visible when the outer reflective surface is not forced very near or against said opaque element on said transparent window, but prevented when said front reflective surface is forced very near or against the opaque element.

Abstract: A pressure sensor includes a sensor chip, a pressure receiving diaphragm, a connector case, and a case. A pressure sensing chamber is provide in the connector case and filled with oil. The sensor chip is arranged in the chamber and the diaphragm is fixed to the connector case such that it has contact with the oil and seals the chamber. An O-ring and a welding ring are placed around an edge of the diaphragm and the chamber between the diaphragm and the connector case. The diaphragm is fixed to the connector case via the O-ring and the welding ring and fixed. An inner portion of the welding ring is formed such that it can be placed between the sensor chip, wires, and the diaphragm in the chamber.

Abstract: A test apparatus and method of electrical testing especially useful for verifying normal performance of essential functions in an aircraft atmospheric pressure responsive auxiliary altimeter under either of flight line or maintenance shop conditions. The tester provides electrical power and control signals needed to energize each of three functions in the considered altimeter instrument including instrument face illumination, altimeter stiction-limiting mechanical vibration generation, aircraft output signal generating potentiometer function and enables electrical current and voltage monitoring relating to the instrument functions being tested. Replacement of individual test instruments and other informal test apparatus with a convenient and probably more electrical accident-free integrated tester is contemplated.

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 chamber (58) containing a fluid at a reference pressure, such that the flexible membrane (50) deflects due to pressure differentials between the reference pressure and the fluid pressure; and, associated circuitry (34) for converting the deflection of the flexible membrane (50) into an output signal indicative of the fluid pressure; wherein, the membrane (50) is at least partially formed from a metal ceramic material. Metal ceramics can be deposited as a thin membrane with sufficient flexibility for sensing pressure while providing corrosion and wear resistance. Furthermore, these materials are generally well suited to micro fabrication processes and electrically conductive so they can be used in capacitative and resistive type pressure sensors.

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 digital pressure gauge comprises a power supply, an input button unit, a pressure sensor, a display unit, a warning unit, and a control unit. The control unit counts the number of operations and/or operation duration of the digital pressure gauge and generates an alarm through the display unit and the warning unit when the counted number of operations and/or operation duration of the digital pressure gauge exceeds a threshold.

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 (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, so that, associated circuitry (34) can convert the deflection of the flexible membrane 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 includes a membrane having a radially peripheral edge region fixedly arranged on a support. One side of the membrane can be acted on by a medium being measured and the membrane can be deflected in response to pressure of the medium. Measuring elements and an electric circuit interconnecting the measuring elements are arranged on the membrane, the measuring elements and the circuit being applied by the thick-film technique and sintered on in a thermal process. The membrane is made of an electrically conducting metal and bears an insulating layer, on which the measuring elements and the electric circuit are arranged. In this case, the insulating layer consists of a material having a coefficient of expansion that lies between the coefficient of expansion of the metal of the membrane and the coefficient of expansion of the material of the measuring elements and the electric circuit.

Abstract: A pressure sensor device having a temperature sensor includes a pressure sensor, a temperature sensor, a sensor casing for accommodating the pressure sensor and a connector pin for electrically connecting the pressure sensor and an outside circuit, and a port mounted on the sensor casing and having a pressure introduction port for introducing a measuring object to the pressure sensor. The temperature sensor is disposed in the pressure introduction port, and electrically connects to the connector pin through a lead wire. The lead wire with the temperature sensor is supported by a connection portion disposed between the connector pin and the lead wire. The lead wire has a buffer disposed between the lead wire and a part of the pressure introduction port for reducing a vibration of both the temperature sensor and the lead wire.

Abstract: A piezoelectric cantilever pressure sensor array is disclosed. The piezoelectric cantilever pressure sensor array contains a substrate, a readout circuit, and piezoelectric cantilever pressure sensors electrically connected to the readout circuit. Each piezoelectric cantilever pressure sensor contains an elongate piezoelectric cantilever mounted at one end on the substrate and extending over a cavity. The piezoelectric cantilever contains a piezoelectric layer sandwiched between two electrodes and generates a measurable voltage when deformed under pressure. The piezoelectric cantilever pressure sensor array can be manufactured at low cost and used in various applications including fingerprint identification devices.

Abstract: A differential pressure sensor chip (4) comprises a diaphragm for measuring a differential pressure and converts a pressure received by the diaphragm for measuring the differential pressure into an electrical signal. A static pressure sensor chip (5) comprises a diaphragm for measuring a static pressure and converts a pressure received by the diaphragm for measuring the static pressure into an electrical signal. The differential pressure sensor chip (4) and static pressure sensor chip (5) are mounted on a header (1) so that one surface of the differential pressure sensor chip (4) and one surface of the static pressure sensor chip (5) are exposed to the interior of a common pressure introducing chamber (17).

Abstract: In general, a pressure rail can be provide, which includes one or more pressure inlets and a plurality of pressured cavities formed therein. Housing components can be respectively located atop the pressured cavities, such that each housing component is sealed to a respective pressurized cavity. A connector component can be threaded into the top of each housing component for attachment to a sensor (e.g., a SAW sensor) for testing thereof. Each housing component can be configured from a clear thermoplastic material, which protects the housing components from RF frequencies, and high temperature and pressure conditions.

Abstract: A small-sized pressure sensor having smaller numbers of parts and assembling steps, a simple structure, a high assembly precision, and little dispersion in the operation characteristics, and a method for manufacturing the pressure sensor. The pressure sensor comprises: a base member; a stationary electrode molded so integrally as is exposed from the bottom face of a recess formed in the upper face of the base member; moving electrode receiving portions and molded so integrally in the bottom face of the recess of the base members as are arranged in the periphery of the stationary electrode and as are higher by a predetermined inter-electrode gap than the upper face of the stationary electrode; a moving electrode opposed to the upper face of the stationary electrode through a predetermined inter-electrode gap; and a diaphragm fixed of the open edge portion of the recess of the base member and adhered integrally at the central portion of its lower face to the upper face of the moving electrode.

Abstract: The object of the present invention is to propose an etch channel sealing structure characterized by excellent impermeability to moisture and resistance to temporal change of the diaphragm in the pressure sensor produced according to the sacrificial layer etching technique, and to provide a pressure sensor characterized by excellent productivity and durability. After a very small gap is formed by the sacrificial layer etching technique, silicon oxide film is deposited by the CVD technique or the like, thereby sealing the etch channel. Further, impermeable thin film of polysilicon or the like is formed to cover the oxide film. This allows an etch channel sealing structure to be simplified in the pressure sensor produced according to the sacrificial layer etching technique, and prevents entry of moisture into the cavity, thereby improving moisture resistance. Moreover, sealing material with small film stress reduces temporal deformation of the diaphragm.

Abstract: A pressure sensor has a housing with an opening exposing a cavity, a barrier diaphragm across the opening, a pressure sensing element within the cavity, and a fill fluid within the cavity. The fill fluid comprises a fluid and a filler, the fluid has a TCE associated therewith, the housing has a TCE associated therewith, and the filler lowers the TCE of the fluid to a level matching the TCE of the housing. Accordingly, the housing and the fill fluid do not exhibit temperature induced dimensional changes relative to one another that cause plastic deformation of the barrier diaphragm.

Abstract: A differential pressure indicator has a housing with at least two ports in the housing. One port receives a first pressure, and the second port receives a second pressure. A pressure resistive device is placed between the first port and the second port. The pressure resistive device changes its position when the first pressure exceeds the second pressure by a predetermined amount. A magnet is coupled to the pressure resistive device. A digital displacement sensor senses the position of the magnet. The digital displacement sensor is in communication with an electronic indicator. The electronic indicator activates when the first pressure exceeds the second pressure by a predetermined amount.

Abstract: A device and method for signaling differential pressure change occurring during leak testing of an evaporative emission control space in a motor vehicle fuel system. A casing has sensing ports one of which is communicated to a reference pressure, such as atmospheric pressure, and another of which is communicated to sense pressure in the evaporative emission control space. As difference between the reference pressure and the pressure in the control space changes, the net magnetic flux acting on a magnetoresistive sensor changes. The sensor is electrically connected to the vehicle electrical system for signaling the differential pressure. The device may be used for both positive and negative pressure leak testing.

Abstract: A thermal pressure sensor monitors pressure by measuring effects caused by variations of thermal conductivity between a member and a substrate to which the member is adhered by stiction. The interface between the member and the substrate behaves as an extremely narrow gap. In a preferred embodiment the member is a bridge extending between a pair of cantilever arms. Two pressure sensors may be combined in a Wheatstone bridge configuration. A method for fabricating a pressure sensor according to the invention comprises forming a layer of oxide on a substrate, depositing a layer of material on the oxide layer, forming the member from the layer of material, removing the oxide layer and then bringing the member into contact with the substrate. The portion of the substrate under the member may be patterned with plateaus and valleys.

Abstract: Transfer fluid, in particular for electrical pressure transducers and pressure transmitters, that transfers deflections of a separating element between a substance to be measured and the transfer fluid to a pressure measurement arrangement, the transfer fluid comprising a polyalphaolefin (PAO 6).

Abstract: A micromechanical component in which lateral deformations, i.e., deformations of the component parallel to its two main surfaces, are concentrated in a defined area of the component structure, making it possible to decouple lateral and vertical stresses in the component. The component structure includes at least one bellows-like structure in which lateral deformations of the component are concentrated. A pressure sensor having a micromechanical component of this type may be used, for example, for measured-value detection.

Abstract: A thin pressure sensor includes: a pair of external electrodes, which are respectively made of conductive thin films that are respectively provided with piezoelectric layers on inner sides; and a single internal electrode, made of a conductive thin film, which is sealed between the pair of external electrodes, one of the pair of external electrodes having a conducting window that conducts to said internal electrode. The thin pressure sensor has a simple and thin structure with sufficient durability and mechanical strength.

Abstract: An improved low-cost pressure sensor assembly incorporates a stainless steel sensor element welded to an outboard face of a stainless steel insert captured in a low-cost metal pressure port adapted for attachment to a pneumatic valve. The pressure port includes outboard and inboard cavities separated by neck portion; the stainless steel insert is captured in the outboard cavity, while the inboard cavity is adapted for attachment to the pneumatic valve. The stainless steel insert includes a base portion that seats against an O-ring in a floor of the outboard cavity, and a stem portion within the O-ring that extends axially through the neck portion of the pressure port and into its inboard cavity. The insert has a first bore that extends axially from its outboard face into, but not through, the stem portion, and a second bore that intersects the first bore and opens into the inboard cavity of the pressure port.

Abstract: A port fitting is formed with a closed, pedestal end forming a diaphragm on which a strain gauge sensor is mounted. A support member is received on the pedestal end and is formed with a flat end wall having an aperture aligned with the sensor. A portion of a flexible circuit assembly is bonded to the flat end wall with a connector disposed over the support member. A tubular outer housing is fitted over the several components and its bottom portion is welded to the port fitting while its top portion places a selected load on an O-ring received about the connector as well as internal components of the transducer. In one embodiment, a loading washer (72a) is disposed over the O-ring on a first portion (70a) of a two portion connector (70) and retained by a second connector portion (70b). Protrusions (76a1) formed on the tubular housing (76) pass through cut-outs in the second connector portion to place a load on the loading washer.

Abstract: A relative pressure measuring instrument has a reference pressure feed that offers a high measure of safety and is easy to produce.

Abstract: A port fitting (102) is formed with a closed, pedestal end forming a diaphragm (102a) on which a strain gauge sensor is mounted. A support member (106) is received on the pedestal end and is formed with a flat end wall (106a) having an aperture (106d) aligned with the sensor. A circuit assembly (108) is bonded to the flat end wall and the sensor wire bonded to the electronic circuit. A cover member (114) placed on the support member, is provided with a cavity for a metal shield member (118) fitted inside the cover member before assembly. The shield member is formed with spring members (118b) extending outside the perimeter of the cover member. The cover member is formed with circular cavities (114d) extending in an axial direction to provide seating for contact spring members (117), making electronic contact to the sensor electronics and protruding beyond the body of the cover member. The cover member is also fitted with a circular elastomer gasket member (116), providing an environmental seal.

Abstract: The invention concerns a pressure sensor (1), able to operate at high temperature and measure the pressure of a hostile medium, comprising: a sensing element (4) integrating a membrane (8) in monocrystalline silicon carbide, made by micro-machining a substrate in polycrystalline silicon carbide, a first surface of membrane (8) intended to contact said medium, a second surface of membrane (8) comprising membrane deformation detection means (9) connected to electric contacts (10) to connect electric connection means (11), the surfaces of sensing element (4) contacting said medium being chemically inert to this medium; a carrier (5) to support sensing element (4) so that said first surface of membrane (8) may be contacted with said medium and the second surface of membrane (8) may be shielded from said medium, carrier (5) being in polycrystalline silicon carbide; a seal strip (6), in material containing silicon carbide, brazed between carrier (5) and sensing element (4) to protect the second surface of membra

Abstract: The measuring instrument for a pressure gauge comprises an indicator unit with two plates that bear rotatably an indicator shaft carrying a pinion and that furthermore bear a gear segment. The measuring instrument furthermore comprises a metal Bourdon tube bent into an arc shape, which is soldered on one end to a spring carrier and on the other to a spring end-piece. The spring end-piece is connected to the gear segment such that the displacement of the spring end-piece because of the measurement pressure is transferred to the gear segment. The spring end-piece constitutes a part that is rigidly attached to one of the two plates prior to the Bourdon tube being soldered to the spring end-piece and that is separated from this plate once the Bourdon tube has been soldered to the spring end-piece. During the course of the manufacture of this measuring instrument, the spring end-piece is produced as a part that is securely joined to the two plates.

Abstract: A port fitting is formed with a closed, pedestal end forming a diaphragm on which a strain gauge sensor is mounted. A support member is received on the pedestal end and is formed with a flat end wall having an aperture aligned with the sensor. A portion of a flexible circuit assembly is bonded to the flat end wall with a connector disposed over the support member. A tubular outer housing is fitted over the several components and its bottom portion is welded to the port fitting while its top portion places a selected load on an O-ring received about the connector as well as internal components of the transducer. In one embodiment, a loading washer (72a) is disposed over the O-ring on a first portion (70a) of a two portion connector (70) and retained by a second connector portion (70b). Protrusions (76a1) formed on the tubular housing (76) pass through cut-outs in the second connector portion to place a load on the loading washer.

Abstract: A pressure sensor includes a pair of base films, a pair of electrodes, a layer of pressure-sensitive resistor, a spacer, and a projection. The electrodes are located between the base films. The layer of pressure-sensitive resistor is located between the base films to be distant from one of the electrodes by a predetermined gap. The spacer is located outside the layer of pressure-sensitive resistor between the base films and used for forming the gap. The projection is located on an outer surface of one of the base films in order to decrease the lowest pressure that can be detected by the pressure sensor. The contact state between the layer of pressure-sensitive resistor and one of the electrodes varies to vary the resistance between the electrodes when a pressure acts on the projection.

Abstract: The invention relates to a sensor arrangement with a pressure detector (6) that has a measuring diaphragm, which can be deflected by the pressurized measurement medium. A measuring bridge is provided as a sensor circuit, which is attached directly to the measuring diaphragm. An evaluation circuit is embodied as a hybrid circuit (8) and can be fastened directly to the measuring diaphragm, producing electrical connections (9, 10) between the hybrid circuit (8) and the sensor circuit and a ground connection to the housing (2, 3) of the sensor arrangement (1). The housing (2, 3, 4) of the sensor arrangement (1) is embodied as multi-part and the contacting of the connections of the hybrid circuit (8) with connector pins (11) of the connector (4) can be produced, for example, by means of pressure contacts (12, 13; 23).

Abstract: A pressure detecting apparatus includes: a housing (11) for forming fluid chambers (21A and 21B) into which external fluid pressures are imported respectively; a pressure-receiving member (31) slidably provided in the housing (11) for receiving the fluid pressures from the fluid chambers (21A and 21B); an elastic member (35) supported by the housing (11) and elastically deformed due to a slide displacement of the pressure-receiving member (31) from a predetermined position; a displacement detecting means (12) for detecting the displacement of the pressure-receiving member (31) from the predetermined position; the elastic member including a base portion supported by the housing, an engagement portion engaged with the pressure-receiving member, and a flexible arm extending from the base portion toward the engagement portion along a plane approximately perpendicular to a direction of sliding of the pressure-receiving member.

Abstract: A device for measuring the pressure of blood in a pipe (44) of an extracoporeal blood cicuit, includes a pressure measurement section (46) having a compartment (58) which is delimited especially by a main wall (64) and by a secondary wall (65) facing it. The two walls (64, 65) have a hole (66, 84) which is closed by a closure element (68, 86) which can be elastically deformed under the effect of the blood pressure, and the compartment (58) has a spacer (94) which transmits the movements from the closure element (86) of the secondary wall (65) to the closure element (68) of the main wall (64), so that a load sensor (56) can measure a force which corresponds to a so-called “negative” blood pressure.

Abstract: A diaphragm that distorts according to pressure applied thereon and a signal processor circuit are formed on a semiconductor substrate having an (110)-surface-orientation. Stain gauges converting the diaphragm distortion into an electric signal and forming a bridge circuit are formed on the diaphragm. The electric signal from the bridge circuit is processed by the signal processor circuit. A pair of transistors constituting an input circuit of an amplifier in the signal processor circuit are positioned on the substrate to equalize their source-drain current directions. Thermal stress influence on the sensor outputs is minimized since sensor components are formed on the substrate having the (110)-surface orientation, and thereby the pressure applied to the diaphragm is accurately detected.

Abstract: The invention relates to a method of measuring pressure in which an evacuated capsule (1) containing a resonant element (5) is placed in the fluid whose pressure is to be measured, a vibration characteristic of the element is measured, and the pressure is deduced from said characteristic. A resonant element is used which, during measurement, is to be found in a stress state that is close to buckling. For this purpose, it is possible to use heater means for heating the element and servo-controlled so as to keep the frequency of vibration thereof constant. The resonant element can be made of silicon. The invention is particularly applicable to oil wells.

Abstract: A pressure transmitter with a hermetically sealed housing surrounding a cavity that is filled with a gas that is free of integrated circuit contaminants. A sensor circuit including an integrated circuit is placed in the cavity and a gas fill port on the housing is sealed. The sensor circuit is electrically adjustable from outside the pressure transmitter and the integrated circuit is protected from contaminated atmospheres outside the pressure transmitter.

Abstract: The present invention provides a differential-pressure transducer having two sensors cross-coupled and independently excited. A first Wheatstone Bridge pressure sensor has a first sensitivity and is excited by a first voltage. A second Wheatstone Bridge pressure sensor has a second sensitivity and is independently excited by a second voltage different from said first voltage. The excitation voltages are independently adjusted to increase or decrease the sensitivities of the sensors to substantially match. The outputs of the sensors are cross-coupled to each other to reduce the offset difference errors between the pressure sensors. Sensitive electronics are isolated within the sealed housing to protect them from harsh surrounding media. The transducer is configured to provide either a four pressure differential pressure measurement or a three pressure gauge differential pressure measurement.

Abstract: A semiconductor sensor chip mounted on a thin diaphragm of a cylindrical metallic stem via an insulation layer is hermetically contained in a housing of a pressure sensor. The sensor chip includes a strain gage for outputting an electrical signal according to distortion of the diaphragm caused by pressure to be measured. A shield layer is interposed between the insulation layer and the sensor chip, and the shield layer is grounded. Influence of outside noises on the sensor outputs is eliminated or suppressed by the grounded shield layer even if the outside noises are in a high frequency region.

Abstract: There is disclosed a measurement mechanism for differential pressure measurement. The mechanism has two housing portions with flanges. A differential pressure sensor is force-fit between the two flange faces. An electronics board is connected to the differential pressure sensor by means of a force-fit electrical contact.