Abstract: A pressure sensitive sensor is provided that includes a net braid member formed by knitting a plurality of insulating yarn strands, such as an aramid fiber, interposed between an elastic electroconductive tube and a central electrode member. The elastic electroconductive tube and the central electrode member are brought into electrical contact with each other through the gap portion of the mesh of the net braid member at a pressure point, and pressure is detected. The central electrode member is formed by winding an electroconductive metal wire in a coil on the outer peripheral surface of a central member formed by coating an elastic insulating material on a central reinforcing member formed of an aramid fiber. Thus, a pressure sensitive sensor which has a simple construction, can be produced easily and at low cost, is suitable for making a small sensor, and can appropriately function even if the sensor is warped or kinked at a sharp curvature.

Abstract: The pressure sensor (2) comprises a pressure detector element (21) arranged to receive a pressure that is to be measured and to detect it, and a printed circuit (22) connected to the pressure detector element (21) via an electrical connection, and it is characterized in that the electrical connection comprises at least one flexible conductive tongue (29) having a first end (290) connected directly or indirectly to the printed circuit (22) and a second end (291) merely bearing against a corresponding electrical contact (213a) of the pressure detector element (21). In order to ensure good electrical contact, the bearing face (294) of the second end of the or each flexible conductive tongue (29) bearing against the corresponding electrical contact (213a) is polished.

Abstract: First and second resistors (sensing elements) are connected in series between first and second potentials. The junction point voltage between the first and second resistor is supplied to an inverting input of a first operational amplifier. The non-inverting input is supplied with a reference voltage Vref generated by third and fourth resistors. A feedback resistor is connected between output and inverting input of the operational amplifier OP1. The difference between a temperature coefficient of resistance TCR of the sensing elements and a temperature coefficient of sensitivity TCS is equalized to a temperature coefficient of resistance of the feedback resistor. Further, the reference voltage is unchanged in accordance with the detected physical quantity or temperature variation.

Abstract: The full bridge circuit in a pressure sensor including semiconductor piezoelectric resistive elements in a pressure detection structure is connected to a filter. That is, first and second output terminals of the full bridge circuit is connected to a capacitor. One end of the capacitor is connected to the first output terminal through a first resistor. The other end of the capacitor is connected to the second output terminal through a second resistor. In an exhaust system of an engine, the pressure of the exhaust gas is detected to detect clogging in the black smoke removing unit. The filter removes the pulsate component in the detection signal derived from the pulsate component in the exhaust gas.

Abstract: An integrated microsensor includes a bowed micromachined membrane coupled to a substrate to define a microcavity therebetween. An integrated strain sensor is coupled to the micromachined membrane to generate a signal responsive to (deformation of the membrane and hence responsive to the pressure of the fluid in the microcavity. A frame is coupled to the peripheral edge of the membrane to assist in enlarging the microcavity. The membrane is composed of a nitride of B, Al, Ga, In, Tl or combinations thereof, or more particularly of p-type GaN where the frame is comprised of n-type GaN. The membrane and frame are fabricated using a photoelectrochemical etching technique. The fabrication of the integrated strain sensor creates stresses across the membrane. The strain sensor comprises an integrated circuit strain-FET. The strain-FET comprises an AlGaN/GaN heterostructure having an AlGaN/GaN interface where deformation of the membrane is coupled as strain to the AlGaN/GaN piezoelectric interface.

Abstract: A pressure sensor device is described that has a diaphragm acted upon by a working medium, on a first side, and a sensor chip, which is disposed on a second side of the diaphragm that is remote from the working medium. There is formed in the sensor chip a measuring bridge having four sensor elements, which form two pairs disposed parallel, and the pairs are disposed at right angles to one another. The sensor elements are disposed such that they are closely spaced apart from one another in the edge region of the sensor chip that faces toward the central point of the diaphragm.

Abstract: A sensor unit S for water heating systems, particularly for water boilers, is designed with a single housing H as a combined relative pressure and temperature sensor and has a ceramic support element C carrying an electronic circuit E including separate circuit zones E1, E2 for detecting the pressure and the temperature of the water, the support element including an active functional element M and being directly contacted by the water. The water contact area of said ceramic support element is separated from the electronic circuit E by a seal in the housing H.

Abstract: An absolute micromachined silicon pressure sensor provides the resistive or piezoresistive strain gauges, conductive traces, wirebond pads and other electrical components on a micromachined silicon die in a location that is isolated from the sensed fluid. This protects the electronic components from the corrosive effects of the sensed fluid. A hermetic cover is provided on the backside of the silicon die and is directly bonded thereto to create a hermetically sealed volume of gas or vacuum.

Abstract: The invention creates a micromechanical component, in particular a pressure sensor, comprising: a substrate (2) that has a membrane region (10) and a surrounding region of the membrane region (10); at least one measuring resistance (4a, 4b; 41, 42) provided in the membrane region (10) and modifiable by deformation of the membrane region (10); a corresponding evaluation circuit (50) provided in the surrounding region, an interference effect on the measuring resistance (4a, 4b; 41, 42) being producible by way of a deformation of parts, in particular conductor paths, of the evaluation circuit (50) relative to the substrate (2); and at least one patch (60; 70, 70′) provided in the surrounding region and/or in the membrane region (10) and made of a material such that by way of a deformation of the patch or patches (60) relative to the substrate (2), an analog interference effect can be generated in such a way that the interference effect acting on the measuring resistance (4a, 4b; 41, 42) can be compensated

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: A port fitting (12, 42) is formed with a closed, pedestal end forming a diaphragm (12a, 42b) on which a strain gauge sensor (22) is mounted. A support member (16, 44) is received on the pedestal end and is formed with a flat end wall (16a, 44a) having an aperture (16c, 44c) aligned with the sensor. A portion of a flexible circuit assembly (24a, 58a) is bonded to the flat end wall. An electronics chamber is formed in a connector (18, 46) which is inverted and maintained at a selected height adjacent to the flat end wall of the support member to facilitate soldering of the flexible circuit to terminals (20, 48) in the connector and electronic components to the flexible circuit. The port fitting, when assembled to the support member, is also maintained at the selected height adjacent to the inverted connector to facilitate wire bonding the sensor to the bonded portion of the flexible circuit.

Abstract: A reliable sensor provides a user-friendly semiconductor sensing device and transducer which accurately detects the characteristics of a fluid, such as pressure and strain, at high temperature operating conditions. The high performance sensor is particularly useful for use with diesel engines and internal combustion engines in vehicles. The sensor can comprise a single die with a transverse strain gauge or a group of strain gauges which are located at a position on the die to help minimize electric effects of thermal stress on the gauges during pressure detection and operation of the vehicle. The die can be glass fused, such as by glass frit, to a diaphragm, such as a stainless steel diaphragm, so as not to readily corrode in the fluid.

Abstract: A strain gage system for determining state of charge in a battery having a pressure vessel includes a strain gage bridge system mounted on a first cylindrical portion of the pressure vessel. The bridge system has a plurality of active strain gages and no inactive or dummy gages. An electrical output of the strain gage bridge is correlated to a state of charge of the battery.

Abstract: A sensor is proposed that has a measuring diaphragm (2), with at least one resistor measurement bridge (7, 8); a deflection of the measuring diaphragm (2) causes mistuning of the respective measurement bridge (7, 8), and the resultant change in the bridge diagonal voltage can be evaluated. The sensor (1) has one resistor measurement bridge (7, 8) on each half (3, 4) of the measuring diaphragm (2), and in each of the resistor measurement bridges (7, 8), two opposed bridge branches (R1, R4) are changed in their resistance values (&Dgr;R) by radial compressive offset, and the respectively other bridge branches (R2, R3) are altered in their resistances by radial or tangential elongation.

Abstract: A miniature, multi-channel, electronically scanned pressure measuring device uses electrostatically bonded silicon dies in a multi-element array. These dies are bonded at specific sites on a glass, pre-patterned substrate. Thermal data is multiplexed and recorded on each individual pressure measuring diaphragm. The device functions in a cryogenic environment without the need of heaters to keep the sensor at constant temperatures.

Abstract: A pressure sensor is provided for cryogenic, high pressure applications. A highly doped silicon piezoresistive pressure sensor is bonded to a silicon substrate in an absolute pressure sensing configuration. The absolute pressure sensor is bonded to an aluminum nitride substrate. Aluminum nitride has appropriate coefficient of thermal expansion for use with highly doped silicon at cryogenic temperatures. A group of sensors, either two sensors on two substrates or four sensors on a single substrate are packaged in a pressure vessel.

Abstract: A transducer is described especially for use in providing acoustic transmission in a borehole. The transducer includes a multiple number of magnetic circuit gaps and electrical windings that have been found to provide the power necessary for acoustic operation in borehole while still meeting the stringent dimensional criteria necessitated by boreholes. Various embodiments conforming to the design are described. Moreover, the invention includes transition and reflector sections, as well as a directional coupler and resonator arrangement particularly adapted for borehole acoustic communication.

Abstract: A semiconductor component (31) and a method for coupling a semiconductor device (36) to a substrate (81). The semiconductor component (31) includes a saddle (34) and the semiconductor device (36). The saddle (34) has a plurality of sides (51, 52, 53, 54, 55) that form a semiconductor device receiving area (58). The semiconductor device (36) is inserted into the semiconductor device receiving area (58) and secured in the semiconductor device receiving area (58) using tabs (66, 67). The saddle (34) is coupled to the substrate (81) by fasteners (82,83).

Abstract: A differential pressure sensor (10) has a sensor die (30) eutectically attached to a mounting flag (14). The mounting flag has a similar coefficient of thermal expansion to the sensor die. The eutectic attachment provides a hermetic seal between the mounting flag and the sensor die. Pressure is applied to sensor die port (20). A molded housing (12) is molded around the sensor die-mounting flag assembly. Port (22) in the molded housing is filled with a silicone gel (52). A second pressure source is transferred by way of the silicone gel to the sensor die. Any media entering port (20) contacts the first surface of the sensor die to assert pressure against a piezoresistive transducer circuit (32) to generate the electrical signals representative of the applied pressure but are isolated from the sensitive interconnects by the hermetic seal.

Abstract: A good quality passive-state film is formed on a gas-contact face of a diaphragm of a pressure detector using a sensor chip to prevent corrosion on, or water content emission from, or catalytic action at a gas-contact face, thereby improving production quality in a semiconductor manufacturing process and providing high accuracy pressure detection. The passive-state film is formed on the gas-contact face of the diaphragm when the diaphragm is mounted on a diaphragm base. The diaphragm base is then fixedly secured to a sensor base in which a sensor chip is housed and a pressure transmitting medium is sealed in a gap between the sensor base and the diaphragm base.

Abstract: A differential pressure sensor (10) having a housing 12 and a metal or alloy isolator (14) for stress isolation of a sensing cell (28) that is mounted to the isolator (14). The metal or alloy isolator (14) has an opening (16) therein for providing access to the sensing cell (28). The housing (12) is molded around the isolator (14) creating a seal therebetween and isolating the sensing cell (28).

Abstract: A semiconductor pressure detecting device which effectively reduces stress that occurs on a base member due to welding between cap and the base member or any external load. The semiconductor pressure detecting device includes a semiconductor sensor element capable of detecting a strain and/or stress that occurs on a thin-walled pressure receiving portion; a pedestal seat for joining and supporting the semiconductor sensor element; a base member for joining and supporting the pedestal seat; and a cap member welded and joined to the base member so as to cover the base member, the pedestal seat and the semiconductor sensor element.

Abstract: Apparatus is provided for sensing the pressure and temperature of fluid within a cavity of a block, such as hot plastic that flows into a mold cavity. The apparatus includes a piston (30) lying closely but slideably within a bore that extends from the cavity in the block. The outer end of the piston is coupled through a beam structure (36), in a shape of a diaphragm, to a rigid support (40). A strain gauge (44) mounted on the diaphragm senses piston deflection which is proportional to the pressure of fluid in the cavity. A highly heat conductive rod (80) extends through a hole in the middle of the piston, the rod having an inner end (84) that is flush with the piston and the rod having an outer end (86) joined at a thermocouple joint (92), so the temperature of the rod is sensed by the thermocouple to thereby sense the temperature of material in the cavity.

Abstract: The present invention is a semiconductor pressure sensor. In one embodiment, the semiconductor pressure sensor includes a diaphragm having a first thickness and at least cone raised boss that is coupled to a first side of the diaphragm. The at least one raised boss increases the diaphragm thickness in the region occupied by the at least one raised boss to a second thickness. A plurality of piezoresistors are disposed on a second side of the diaphragm in regions of the first thickness. In another embodiment, a semiconductor pressure sensor diaphragm includes at least one raised boss disposed along a central axis on a first side of the diaphragm. At least two raised bridge regions are disposed along the central axis, interconnecting the at least one raised boss and a diaphragm edge. Each raised bridge region is narrower than the raised boss. A plurality of piezoresistors are disposed on the raised bridge regions of the diaphragm along the central axis.

Abstract: A non-zero temperature coefficient of offset (Tco) in a semiconductor device (5) is adjusted by reducing the amount of adhesive material used to secure a first structure to a second structure. An adhesive layer (14) used to secure a sensor die (11) to a constraint die (12) in a pressure sensor application is reduced in thickness and/or formed so that adhesive material does not completely cover the constraint die (12). The Tco is further adjusted by reducing the amount and/or patterning the adhesive layer (18) used to secure the sensor (10) to its package (16).

Abstract: A pressure transducer, in particular for sensing a lateral collision in a motor vehicle, delivers an electric useful signal which is determined by a relative pressure change relating to a pressure event. Low-frequency changes in an output signal of a sensor device, which depend on the ambient pressure, are compensated by a control device with an integrating behavior. The sensitivity of the sensor device, as a manipulated variable, changes in a manner inversely proportional to the ambient pressure. Higher-frequency pressure changes in the output signal of the sensor device are not compensated, but as a result of the variable sensitivity of the sensor device, determine as relative pressure changes the useful signal, which is additionally independent of temperature influences and offset errors of the pressure transducer.

Abstract: An etching method for a silicon substrate, which can easily smooth the etching surface of the (110)-oriented silicon, is disclosed. A container is filled with KOH solution. In the KOH solution is immersed a (110)-oriented silicon wafer having a PN junction and is also disposed a platinum electrode plate to face the silicon wafer. To between a platinum electrode of the silicon wafer and the platinum electrode plate are connected a constant voltage power source, an ammeter and a contact in series. A controller starts etching from one surface on which the PN junction is formed, and terminates voltage application when the specified time lapses after the formation of an anodic oxide film is equilibrated with the etching of the anodic oxide film on the etching surface on the PN junction part.

Abstract: An IC chip for signal processing circuit is enclosed in a mold IC and a pressure sensitive element unit is integrally provided thereon. When the mold IC is housed in a case, the mold IC is fixed to the case under a state where ends of connector pins insert-molded to the case are electrically connected to external terminals of the mold IC. Thereby, a sensor signal is outputted from other ends of the connector pins. By integrating the IC chip for signal processing circuit in the mold IC, the IC chip for signal processing circuit can be protected against a contaminated environment at a location where the pressure sensitive element unit is arranged.

Abstract: A non-invasive sensor assembly device includes a pedestal mounted sensor die for stress isolation of the sensor die from external stresses, a substrate and die porting configuration to limit exposure of the sensor assembly to only the interior of the sensor die and a connecting tube to provide significant isolation of the sensor assembly and its constituent parts from the fluid stream, and an inert coating conformally deposited on the inside surfaces of the die, pedestal, and connecting tube that are in contact with the fluid media to thereby provide complete isolation of the sensor assembly from the media.

Abstract: A media-compatible sensing structure (210) that employs strain-sensing elements (222) formed in or on a silicon chip (212). The sensor (210) generally includes a metal body (214) having a diaphragm (216) and an edge (226) formed by an abrupt change in the thickness of the metal body (214) in a direction normal to the diaphragm (216). The silicon chip (212) is secured directly to the metal diaphragm (216) and has at least one strain-sensing element (222) aligned with the edge (226) of the body (214) in the direction normal to the diaphragm (216), such that movement of the diaphragm (216) induces strain in the silicon chip (212) that is localized at the strain-sensing element (222).

Abstract: Apparatus comprising a flow carrier connectable in a liquid flow system including an electric motor-pump unit and a conduit for conveying a pumped liquid to a liquid utilization apparatus. The flow carrier is connectable in the conduit and includes an opening which exposes the liquid flowing through the carrier. A heat sink or cold plate is located on the carrier over the opening, the heat sink covering the opening and having a wet side exposed to the liquid. The heat sink further includes a dry side, and heat generating control components are secured to the dry side. A sensor is also mounted on the heat sink and responds to a characteristic, such as the pressure, of the liquid. The sensor and the control components are operable to control the motor-pump unit. In a domestic water supply system, for example, the liquid utilization apparatus includes the plumbing in a building. In a gasoline supply system, the liquid utilization apparatus comprises a gasoline dispenser.

Abstract: A compact pressure detecting apparatus comprising a pressure sensor unit, having a semiconductor pressure-detecting device provided with gauge resistance, integrated with a solenoid valve unit for controlling a channel of a measurement fluid into the body of the apparatus. The semiconductor pressure-detecting device partitioned a sensor vessel into a reference pressure chamber and a measurement fluid introduction chamber the measurement fluid introduction chamber can communicate with an environment outside of the pressure sensor unit the pressure-detecting device has a base with a through-hole, on which an electronic circuit and the pressure sensor are mounted.

Abstract: The present invention provides a pressure sensor device which is media compatible and very inexpensive.A medium compatible device according to the present invention for sensing pressure comprising means for sensing pressure; means for providing an output in response to the pressure sensing means; and means for packaging the pressure sensing means and the output means, the packaging means including a non-adhesive means for combining the pressure sensing means and the output means.

Abstract: A method of compensating for differences of temperature, in a pressure sensor of the kind wherein a pressure is sensed by use of a diaphragm connected in a Wheatstone bridge circuit. First measurement points of offset output signals emanating from the bridge in the pressure sensor at a number of temperature levels are plotted in a first graph indicating the voltage as a function of the resulting resistance of the bridge, whereupon adjacent measurement points are interconnected by straight lines and calculation is effected through interpolation between the measurement points. The sensitivity of the pressure sensor such as voltage/pressure unit, is determined in a corresponding manner at different temperature levels by plotting second measurement points in a second graph indicating the sensitivity as a function of the resulting resistance in a similar way the last mentioned measurement points are interconnected by straight lines, and calculation is effected through interpolation between the measurement points.

Abstract: A combustion pressure sensor suitable for a highly precise combustion control system of an automobile engine and a sensing system using the sensor. The combustion pressure sensor includes a SOI substrate having a three-layered structure of a first silicon plate, a thermal oxide film, and a second silicon plate, wherein a combustion pressure is sensed on the basis of a pressure or a force applied to the first silicon plate.

Abstract: A pressure detecting apparatus includes a sensing body with a diaphragm to which pressure is applied and a strain gauge plate having a {100} silicon substrate and a glass base, which is bonded on the sensing body. A thin portion and through holes are formed in the silicon substrate so that the thin portion has a beam structure on which strain gauges are formed. When the pressure is applied, the resistances of the strain gauges change in a positive direction, while the resistances of the strain gauges change in a negative direction. Accordingly, the linearity of the output from the pressure detecting apparatus can be improved.

Abstract: A compensation circuit for a resistance bridge corrects errors in the response of signal outputs thereof and has a voltage controlled current source across a power input and a ground reference providing a bridge excitation output current proportional to a fixed circuit reference voltage. A single resistor adjusts positive or negative values of the fixed part of the offset errors in the signal outputs response. Another resistor adjusts positive or negative slope of the temperature dependent part of the offset errors in the signal outputs response. A method compensates the offset errors with steps of energizing the bridge and measuring the output and resistance at two temperatures and at two pressures. The measurements are used to find correction resistances for variations in bridge offset, temperature and pressure response.

Abstract: The present invention provides an improved method of wire-bonding on a semiconductor chip, especially a small acceleration sensor chip which is mounted on a substrate with an adhesive having low stress characteristics such as a silicon resin. Further, the present invention provides a semiconductor device having a structure in which the improved method of wire bonding is easily applicable. The wire-bonding is performed by giving ultrasonic vibrations to the wires and the pads on which the wires are bonded while imposing pressure thereon. The vibration is given in a direction along a radial line extending from the center of the semiconductor chip.

Abstract: A variable capacitance fluid pressure sensor of the type which includes a deflectable member includes a contaminant exclusion system which protects the deflectable member from both solid and non-solid fluid-borne contaminants. A system of traps disposed between the fluid inlet to the sensor and the deflectable member prevents deposition of process vapors in the fluid on the deflectable member and collects a variety of sizes of fluid-borne solid contaminants remote from the deflectable member.

Abstract: A method of securing a pressure sensor diaphragm to a pressure sensor base, including the steps of positioning the pressure sensor diaphragm over the pressure sensor base, placing a pressure sensor cap over the pressure sensor diaphragm, applying a tensile force to at least a portion of the cap, and deforming a portion of the cap around a portion of the base. The applying step can occur before the deforming step by engaging a portion of the cap and advancing the base toward the cap to create tension in a portion of the cap. This creates a tensile preload in the cap. The applying step can instead be performed during the deforming step by engaging a first portion of the cap and advancing a second portion of the cap toward the first portion of the cap and around a portion of the base. This can create tension in a portion of the cap when the deformation operation is being performed.

Abstract: A pressure sensor is provided with a compressible insert that is disposed within an internal opening of a potentially frangible component, such as a tubular glass member. If a condensate forms within the internal opening of the tubular glass member, freezing of the condensate can cause it to expand and damage the glass member. The compressible insert absorbs the expansion of the liquid condensate by compressing and prevents the expanding condensate from cracking the tubular glass member. The compressible insert, in a particularly preferred embodiment of this invention, has an opening extending therethrough to facilitate the transmission of pressure throughout the aligned openings of the pressure sensor. In one particular embodiment, a silicone die is etched to provide a cavity and corresponding diaphragm portion on which piezoresistive elements are disposed.

Abstract: A semiconductor substrate has a surface layer disposed underneath a gate electrode of a field-effect transistor and having a resistance higher than the resistance of an inner layer which is formed in the semiconductor substrate below the surface layer. The surface layer is formed when a donor doped in the surface layer and an acceptor generated based on a compressive stress which is developed in the surface layer when the gate electrode is formed substantially cancel out each other. The field-effect transistor operates alternatively as a junction field-effect transistor when the surface layer is turned into a p-type structure when a compressive stress is generated in the surface layer and a metal semiconductor field-effect transistor when the surface layer is turned into an n-type structure when a tensile stress is generated in the surface layer.

Abstract: A pressure sensor is provided with an insert member that reduces the dead space of a fluid conduit used to provide fluid communication between a pressure sensitive component and a cavity within which a volume is contained. The insert member is provided with a channel formed in its outer surface so that continued fluid communication can be maintained between the fluid whose pressure is to be monitored and a pressure sensitive component disposed within the structure of the pressure sensor. The use of the insert member significantly facilitates the manufacture of the pressure sensor and reduces the need to utilize pins of excessively small cross sectional area during the molding process.

Abstract: A pressure sensor comprising a hollow main body (1) defining a bore (3) extending therethrough. A pressure sensing assembly (12) is disposed within the bore (3) to divide it into a detection cavity (3a) for transmitting therethrough the pressure to be detected at a pressure receiving end (3c) thereof and an output cavity (3b) through which an output signal from the pressure sensing assembly (12) is to be supplied. A flexible metal diaphragm (40) is attached to the main body (1) at the pressure receiving end (3c) to seal the detection cavity (3a) in which a pressure transmitting medium (11) is filled. The flexible metal diaphragm ( 40) has a resonance frequency above an oscillation frequency range of the pressure to be detected. Preferably, the effective diameter of the diaphragm (40) may be from 7.5 mm to 8.5 mm and the thickness dimension thereof may be from 35 .mu.m to 45 .mu.m.

Abstract: A nonintrusive diesel engine cylinder pressure transducer includes a congruously shaped fuel injector stud which has been internally instrumented with full-bridge electrical resistance strain gage circuitry. The instrumented fuel injector stud has a hole which has been bored axially lengthwise and a full Wheatstone bridge strain gage unit which has been situated in the hole. While the engine is running, the operative instrumented fuel injector stud, which has been replaced in its normal position in the fuel-injector/cylinder assembly, acts in combination with other assembly components as a cylinder pressure transducer. Measurements of tension and compression of the stud are provided which are reflective of pressure, mainly due to compression and combustion, in the engine cylinder. The full-bridge configuration eliminates bending effects and affords electrical temperature compensation. Practice of this invention advantageously avails existing structure.

Abstract: A device and method for remotely zeroing a hydrostatic pressure compensation device are described which permit a fluid transducer, such as is used in conjunction with an intravenous catheter for the measurement of blood pressure, to be zeroed regardless of its elevation. A hydrostatic pressure compensation tube is placed in closed fluid communication with both faces of the transducer so as to provide the same pressure to each side. As an example, the transducer may measure the deflection with a piezoresistive or piezoelectric crystal or may alternatively utilize a semiconductor membrane with implanted resistive elements. The transducer may be coupled or formed integral to a manifold. In such a device, the transducer may be zeroed at any vertical position.

Abstract: A polycrystalline pressure sensor is formed by depositing polycrystalline silicon piezoresistors on a polycrystalline sensing diaphragm. The piezoresistors are arranged in a wheatstone bridge configuration. During operation, an alternating differential signal is applied across the input of the wheatstone bridge. A measured voltage difference between the output terminals of the wheatstone bridge is used to detect imbalance in the electrical piezoresistors that corresponds to pressure applied to the sensor. Pressure is thereby measured.

Abstract: A force sensor assembly incorporates an integrated plunger to provide an economical assembly which can be calibrated and mounted as a single unit. The force sensor assembly utilizes a retainer to movably capture a solid interface within an opening in the retainer. The solid interface includes a flange positioned within the assembly below the retainer opening. The flange dimensions are greater than the retainer opening to retain the solid interface within the assembly. The retainer is attached to a housing body having a gel filled cavity underlying the retainer opening. A diaphragm free floats on the gel within the housing body and contacts the solid interface. The gel transmits a force exerted on the diaphragm from the solid interface to a pressure sensor mounted at the base of the housing body cavity. A ceramic substrate having an integrated resistor network supports the pressure sensor and an amplifier.

Abstract: A seal comprising two rings is disclosed. A sensor or signal generator is immovably affixed to the polymeric member of one of the rings. In one embodiment, the other of the rings includes a corresponding sensor or signal generator, depending on which of these types of elements is affixed to the first ring, that is immovably affixed to the second ring.

Abstract: A multi-function differential pressure sensor includes a semiconductor chip, a stationary base having a joining portion joined to a thick wall portion of the semiconductor chip, and a housing joined to the stationary base. The semiconductor chip is provided with a differential pressure detection unit, a static pressure detection unit, and a temperature detection unit. The joining portion of the stationary base is not thicker than the semiconductor chip. The stationary base has one or more thin wall portions located, in a plan view, within a circular pressure sensitive diaphragm of the semiconductor chip.