Abstract: This invention relates to a semiconductor sensor for detecting external physical forces, such as acceleration, contact pressures, air pressures, mechanical vibrations, etc. The semiconductor sensor according to this invention is characterized by the use of compound semiconductors of high piezoelectricity, such as GaAs, etc. Conventionally sensors of the cantilever type, diaphragm type, etc. are made of silicon. These prior art sensors have low detection sensitivity, and their characteristics tend to deteriorate. The sensor according to this invention is made of GaAs, which has high piezoelectricity and can retain good characteristics of the semiconductor even at high temperatures and includes a field-effect transistor formed on the GaAs for sensing a stress. The FET is driven by a constant current or a constant voltage so as to detect a change of an electrical characteristic (e.g., threshold characteristic) due to a stress.

Abstract: A vortex sensor 14 measures a flow rate of a fluid flowing through a flow passage by detecting alternating pressure variations 26a and 28a generated by a shedding body 16 placed in the flow passage. The vortex sensor 14 includes a sensor housing 32 enclosing piezoelectric sensing elements 62, 64 which are acted on by a movable member 30. The lifetime of the sensing elements in the closed interior is enhanced by providing surface barriers, oxidizing exposed interior surfaces, or providing a gas reservoir. In applications where fluid leakage may be accepted, a controlled leak restrictor provides a limited rate diffusion path to the atmosphere allowing a minimum partial pressure of oxygen to be maintained.

Abstract: A microsensor or micromechanical device based upon the piezoelectric properties of thin film lead zirconate titanate (PZT) with a thickness of between 0.1 and 5 microns. The thin film PZT is sandwiched between first and second electrodes which are provided with electrical connection means for electrically connecting the electrodes to a voltage sensor or voltage source. The invention also relates to a method for making such microsensor or micromechanical device.

Abstract: Single-piece manifold for use in pressurized painting equipment which is configured and arranged for joining a liquid inlet line, a pressure sensor, a filter, a pressure relief valve, and one or more liquid outlet lines by a streamlined network of passages in a compact and organized manner which eliminates static flow areas. The pressure sensor is assembled within the manifold in such manner as to avoid relative rotation between sensor components and thus avoid stressing electrical leads of the sensor.

Abstract: A resistive strain gauge pressure sensor including upper and lower housings coacting to define a pressure chamber within the housing. A board member is clamped between the housings and defines a diaphragm portion which extends across the pressure chamber to divide the pressure chamber into upper and lower chamber portions. All of the circuitry of the sensor is screen printed onto the lower planar face of the board member including the various resistor elements of the strain gauge assembly, the various elements of the conditioning circuit receiving the output of the strain gauge assembly, and the various further leads required to connect the circuitry elements to the terminals of the sensor. The sensor terminals are provided by a plurality of connector pins extending downwardly through the board member for connection at their respective lower ends to the circuitry provided on the lower face of the board member.

Abstract: A pressure sensor comprising a case, a diaphragm provided within the case, a pressure detecting part provided within the case for detecting pressure applied to the diaphragm, and a pressure transmission chamber formed between the diaphragm and the pressure detecting part for sealingly accommodating therein liquid through which the pressure is transmitted from the diaphragm to the pressure detecting part. The pressure transmission chamber is arranged to cope with the volume changes of the liquid due to the temperature changes thereof.

Abstract: A cartridge forming a pressure measuring device is composed of main casing, a bushing detachably screwed to the casing and a coupling piece detachably screwed to the casing. The coupling piece has a plug which serves to establish hydraulic connection with some appliance to permit hydraulic fluid to act on a diaphragm configured as an integral thin wall of the coupling piece. A strain gauge sensor is mounted on the diaphragm and produces electrical signals on leads as the diaphragm deflects as a result of exposure to the pressure fluid. An amplifier serves to amplify the signals from the sensor for further processing and utilisation. The amplifier is mounted to the coupling piece with the aid of elongate conductive pins which also serve to connect the sensor leads to the amplifier.

Abstract: Integrated circuits are formed by bonding two substrates together on a moat or recess. If the moat is exposed at a side wall, an optical fiber is inserted therein and communicates optically with a photoelectric device in the substrate by a slant side wall of the moat. If the moat is sealed by a cover layer resulting from removing all or most of the top substrate leaving the bonding layer as a cover, a pressure responsive device is formed on the cover layer directly or in the remaining top substrate over the sealed cavity.

Abstract: A precision pressure sensor in the form of a load cell has a mounting ring closed at one end by an end wall which has axially outwardly facing dead-end holes therein to form sensor beams each having an axially outwardly facing plane surface to which strain gages are bonded. The dead-end holes have bottoms forming sensor membranes. Opposite the closed end the mounting ring encloses a cavity forming a sensor space which is closed by a closure plug that simultaneously has a bore for admitting fluid under pressure to be measured into the sensor space. A ring groove in the end wall has approximately radially sloping surfaces which together with the dead-end holes determine the minimum cross-section of the measuring beams. The ring groove also determines the minimum thickness of the sensor membranes.

Abstract: A differential pressure transducer has a first pressure chamber, defined by a first chip having a reduced-thickness first pressure-sensitive diaphragm on one side of that pressure chamber, and a second chip having a reduced-thickness second pressure-sensitive diaphragm on another side of that pressure chamber. A first pressure port communicates with that first diaphragm on a side opposite the first pressure chamber and a second pressure port is coupled to the first pressure chamber. A second pressure chamber is on a side of the second diaphragm opposite the first pressure chamber. Sensors are at the first diaphragm for measuring differential pressure between said first and second ports and at the second diaphragm for measuring differential pressure between said first and second pressure chambers. An aperture may extend through one of the chips in a region spaced from its pressure-sensitive diaphragm, which may therethrough be coupled to the second pressure port.

Abstract: The invention relates to a pressure or force sensor having an axially symmetrical, force-receiving circular plate spring which has a reinforced edge region (5) which serves as a support on a carrier, said spring being provided with strain gauges. To prevent radial sliding motions between the carrier and the circular plate spring the carrier is fitted at the reinforced edge region of the circular plate spring in an annular zone, in which the radial expansion is substantially zero.

Abstract: A vortex sensor 14 for measuring a flow rate of a fluid flowing through a flow passage. The flow rate is measured by detecting alternating pressure variations 26a and 28a generated by a shredding body 16 placed in the flow passage. The vortex sensor 14 includes a sensor housing 32 having two cavities 44 and 46 interconnected by a channel 42. An Axle 52 of a spool member 34 is slideably disposed in the channel 42 and allows each of two flange members 54 and 56, connected proximate each end of the axle 52, to shuttle back and forth with respect to the sensor housing 32. A piezoelectric sensing element 62, 64 and a biasing mechanism 58, 60 are disposed between the flange members 54 and 56 and the sensor housing 32. The alternating pressure variations are applied to each flange member 54, 56 causing the spool member 34 to shuttle back and forth. When the spool 34 moves, mechanical forces are coupled to each sensing element 62 and 64 by biasing mechanisms 58 and 60.

Abstract: A semiconductor pressure transducer for detecting a pressure applied to a diaphragm.

Abstract: A wet-to-wet pressure sensor package (10) having a housing (12) with a pressure sensitive semiconductor die (34) supported within a resilient mounting (44) including continuous beads (46, 48) of elastomeric adhesive on the same portion of the housing to provide a protective seal with less stress so that improved sensitivity and repeatability of the wet-to-wet pressure sensor is achieved.

Abstract: The pressure sensor has a housing, a sensing body mounted inside an internal space of the housing and having a cavity, one end thereof being open and other end thereof being closed, to form a pressure introducing portion therein, the closed end thereof having a thin thickness forming a diaphragm for receiving a pressure, and a semiconductor chip mounted on one surface of the closed end opposite to the diaphragm for receiving a pressure. The pressure sensor is characterized in that the sensing body is attenuated at a portion including at least the closed end thereof and has a diameter smaller than that of the remaining portion thereof, and a shoulder is provided therebetween, whereby the sensing body is fixedly connected to the internal space of said housing by abutting the shoulder thereof against a stopper portion provided in the internal space of the housing and the external surface thereof is placed in contact with the inner surface of the internal space of the housing.

Abstract: The present invention entails a force multiplying instrument that functions to multiply an input force, such as input pressure signal. A substantially constant area membrane is preshaped to assume a concave-convex shape and is disposed within a housing structure where it extends across an open chamber within the housing structure and is secured about its periphery by the side walls of the housing structure. For positive multiplication, a force sensing system is disposed on the concave side of the membrane and actually extends into engagement with the membrane for supporting the same about the concave side. Because the membrane is preshaped, it extends inwardly at a selected angle relative to the horizontal plan of the periphery of the membrane secured within the housing. The force applied to the convex side of the membrane and transferred against the force sensing system is multiplied because of the angle of the membrane and the position of the force sensing system.

Abstract: An apparatus for sensing differential pressures is provided. The apparatus includes a housing having an inner chamber filled with an incompressible working fluid. First and second diaphragms are provided in said housing for interacting with the fluids being measured. A flex-tube is provided in the housing and is coupled to one of the diaphragms for sensing the differential pressure. One end of the flex-tube is securely mounted to the housing and the other end is coupled to the diaphragm. A quartz sensor is positioned on the core for sensing strain applied to the flex-tube by the differential pressure exerted on the diaphragm.

Abstract: In order to improve the stabilization and the heat-resistance of a strain gauge, the strain gauge is made of an amorphous alloy including Ni (nickel), Cr (Chromium) and Si (silicon). The amorphous alloy including Ni, Cr and Si has a high crystallization point, its temperature co-efficient of resistance is almost zero obtained by annealing. The amorphous alloy is stabilized from low to high temperatures and thus can be used from low to high temperatures without compensation. The amorphous alloy is a non-magnetic substance and the strain gauge thus is not substantially affected by external electromagnetic noise.

Abstract: A cell for sensing differential pressures has a single brittle material diaphragm mounted on support plates positioned on opposite sides of the diaphragm. The diaphragm surfaces when at zero differential pressure facing the support are concave and shaped to conform very closely to the shape the diaphragm has when it is deflected so that when the diaphragm is under a selected pressure and it is forced against one of the supports in either direction, the diaphragm is substantially planar or flat and supported fully on its support plate. The diaphragm may be shaped by placing it under a pressure so that it bows or deflects and then grinding the surface opposite from the applied pressure flat. When the pressure is removed, the diaphragm relaxes and a cavity with the exact required shape is produced on the surface that had been bowed out and ground flat. The same procedure can be done to the other side of the diaphragm or two diaphragm sections may be fixed together.

Abstract: In a mechanical electrical transducer strain-sensitive resistors (26, 27) are arranged on a strain member (7, 28, 38, 51, 53) in each case on sections (16-18; 32, 33; 45-48; 58-60) developed in transverse-beam fashion, which from the center of the strain member, are arranged tangentially to a circular arc extending concentrically to the center of the strain member. The transverse-beam sections are subjected on their surfaces substantially only to one-dimensional states of stress. The pairs of strain sensitive resistors are therefore stressed in a manner which does not simulate changes in pressure.

Abstract: Disclosed is an apparatus for pressure sensor compensation. The invention is best suited for pressure sensors of the type which may be mounted about a flexible member such that the resistance of one or more strain gauge resistors mounted thereon changes as pressure is exerted upon the flexible member. The pressure sensing apparatus comprises a bridge resistor arrangement for sensing pressure, and bridge control circuitry, coupled to an input terminal of the bridge, for compensating temperature induced variances in the bridge by controlling the voltage at the input terminal. The bridge has at least a first strain gauge resistor mounted on the flexible member, and at least one output terminal having a voltage which changes as pressure is exerted upon the flexible member. The bridge control circuitry has an additional strain gauge resistor which is used to monitor the temperature of the first strain gauge resistor.

Abstract: A differential pressure transducer determines a differential between two pressures. The transducer comprises a closed measuring chamber formed by at least two measuring membranes arranged to be acted upon by the two pressures, respectively. At least one pressure chamber is defined by a transmission membrane and one of the measuring membranes. A bendable bar is disposed in the pressure transmission chamber, i.e., outside of the measuring chamber, and is operably connected to the measuring membranes to be bent thereby in response to a pressure differential. Strain gauges are mounted on the bendable bar for detecting the amount of bending of the bar, thereby enabling the pressure differential to be determined.

Abstract: A range spring assembly for a differential pressure responsive device which includes a spring retainer plate configured for coaction with a movable portion of a device, such as a bellows or diaphragm. A flat spiral spring in spaced relation to the retainer plate is provided with a clamp disc. A plurality of helical range springs are equiangularly disposed about a circumference inwardly of the periphery of the retainer plate, each of the range springs having a first end thereof securely attached to the retainer plate adjacent the center thereof, with the other ends being selectively attachable to the clamp disc, whereby the range may be readily established by locking one or more ends of the helical springs for providing the desired spring bias for the selected range.

Abstract: A pressure sensor converts a fluid pressure into electric signals upon displacement of a diaphragm. The pressure sensor includes a plurality of strain gauges which are formed on a moveable part of the diaphragm with terminal portions formed on a stationary part of the diaphragm. Readout wires are connected to the terminal portions of the strain gauges on the stationary part of the diaphragm.

Abstract: In a pressure sensor for detecting the air pressure in the interior of tubeless tires of motor vehicles, on a rim having two edge beads extending around its outside and a drum-like base, to facilitate mounting and provide malfunction-free, exact detection of pressure it is provided that the pressure sensor (10) is disposed in a bore (9) of the preferably radially inner section (5) of a bead (3), and in particular the longitudinal axis (43) of the pressure sensor (10) forms an acute angle with the axis (44) of the rim.

Abstract: A differential-pressure instrument the body of which forms a sealed interior pressure chamber containing a fill-liquid and includes a pair of flexible diaphragms to apply to the fill-liquid an input differential pressure to be sensed by an IC strain-gauge chip within the chamber. A spring plate divides the interior pressure chamber into two sections and is deflectable in response to differential pressures. Overrange pressure protection is provided by a valve which is closable by an elastomeric pad carried by the spring plate when the plate deflection reaches a pre-set amount. Valve closure locks the fill-liquid in place alongside the plate to provide an incompressible liquid back-up preventing further deflection of the plate, thus preventing further increases in differential pressure across the IC chip. In one embodiment, valves are placed on both sides of the spring plate to protect against both high-side and low-side overrange pressures.

Abstract: A differential pressure transmitter has a body wherein a pressure transmission passage filled with a pressure transmission medium is formed. A differential-pressure/displacement converting element is disposed in the body to partition the passage into a high-pressure side section and a low-pressure side section. A first seal port through which the transmission medium is charged into the high-pressure side section and a second seal port through which the transmission medium is charged into the low-pressure side section are formed in the body. First and second throttle members capable of being taken out through the seal ports are disposed in the high- and low-pressure side sections to throttle the sections.

Abstract: A pressure transducer with a diaphragm coupler at one end and a sensing element at the other end connected by a capillary tube. The sensing element includes a cap member having a deformable surface including a top wall forming a thin diaphragm having a diametrically disposed raised beam extending across the top surface and having a gage received surface for receiving a plurality of strain gages. The deformable top wall surface has indentations therein on either side of and extending longtudinally of the raised beam to reduce tension forces across the diaphragm and improve linearity of the diaphragm.

Abstract: A pressure transducer with a diaphragm coupler at one end and a sensing element at the other end connected by a capillary tube. The sensing element includes a cap member having a deformable surface including a top wall forming a thin diaphragm having a diametrically disposed raised beam extending across the top surface and having a gage receiving surface for receiving a plurality of strain gages.

Abstract: A differential-pressure instrument the body of which forms a sealed interior pressure chamber containing a fill-liquid and includes a pair of flexible diaphragms to apply to the fill-liquid an input differential pressure to be sensed by an IC strain-gauge chip within the chamber. A spring plate divides the interior pressure chamber into two sections and is deflectable in response to differential pressures. Overrange pressure protection is provided by a valve which is closable by an elastomeric pad carried by the spring plate when the plate deflection reaches a pre-set amount. Valve closure locks the fill-liquid in place alongside the plate to provide an incompressible liquid back-up preventing further deflection of the plate, thus preventing further increases in differential pressure across the IC chip. In one embodiment, valves are placed on both sides of the spring plate to protect against both high-side and low-side overrange pressures.

Abstract: An axially arranged solid state semiconductor pressure sensor assembly is provided in which the semiconductor pressure sensing die is mounted on an internal sub-assembly which is functionally testable and which mates with a variety of different external sleeves individually adapted to attach in different ways to the vessel or system containing the pressure intended to measured. The sub-assembly comprises a cylindrical dielectric body having a platform parallel to the axis of the cylinder. The body contains electrical leads aligned parallel to the platform and extending from the region adjacent to the platform where wire bonds may be made directly to the sensor chip, to the opposite end of the body. A hole and channel arrangement is provided through the dielectric body to the central portion of the platform for communicating the reference pressure to the rear face of the semiconductor die.

Abstract: A monolithic accelerometer is fabricated with an integral cantilever beam sensing element which is etched out of a silicon wafer from the back surface. A thermal silicon oxide is formed on both surfaces of a (100) silicon wafer. Silicon oxide is removed from the back surface in a pattern which defines the sides of the cantilever beam and the sides of an alignment groove. The width and orientation of the openings in the silicon oxide are selected to control the depth of etching when the wafer is subsequently etched with an anisotropic etchant. An integrated circuit is then formed on the front surface and dry etching is used to complete the groove and separate the sides of the beam from the wafer.

Abstract: A low cost piezoresistive pressure transducer utilizing premolded elastomeric seals and adapted for automatic assembly, and a method of producing the transducer. A piezoresistive stress sensitive element in the form of a diaphram of semiconductor material having a thickened rim is held at its rim between a pair of premolded elastomeric seals in a thermoplastic housing. Electrical connections with external circuitry are made with strain relief jumpers which connect conductive regions on the element outside the seals to conductors which pass through the housing wall.

Abstract: A circular diaphragm with an annular thin portion has a smooth front surface, and coaxial but spaced inner and outer cylinders are secured to a rear surface of the diaphragm across said annular thin portion. Opposite edges of a rectangular strain member which is operatively connected to the disphragm through the inner cylinder are secured to a free end of the outer cylinder.

Abstract: A diaphragm-type pressure sensor employs a monocrystalline wafer as a pressure-responsive diaphragm. The wafer has a central active area surrounded by a first bonding area on one side and a second bonding area on the other side. The first bonding area is attached by a first layer of bonding material to a base, and the second bonding area is attached by a second layer of bonding material to a cap. The inside diameter of the first bonding layer is greater than the inside diameter of the second bonding layer by an amount of at least approximately six times the thickness of the diaphragm. This disparity between the respective inside diameters of the two bonding layers results in the relief of radially-directed tensile loading on the first bonding layer when a pressure to be measured is applied to the first side of the diaphragm. Consequently, the probability of a fracture occurring in this bonding layer is minimized.

Abstract: A pressure or pressure difference measuring instrument with a central part which has separating seal diaphragms at its end faces and which contains a pressure-sensing device is disclosed. In order to arrange the pressure-sensing device in the central part, the central part is provided in a circumferential area between the end faces with a pot-like recess into which a carrier for the pressure sensing device is inserted. The carrier has a cross hole which changes into a pressure-transmitting canal in the central part in such a position that due to the carrier being welded to the central part, there is produced at the same time a seal in the area of the point of transition from the cross hole to the pressure transmitting canal.

Abstract: A combustion pressure sensor has a first diaphragm adjacent a combustion region for deflecting in response to the magnitude of adjacent pressure. A second diaphragm is spaced from the first diaphragm and deflects as a function of the deflection of the first diaphragm. The second diaphragm is adapted to generate a signal indicative of the deflection of the second diaphragm. A force transmitting means between the first and second diaphragms transmits movement of the first diaphragm to the second diaphragm and reduces heat transfer from the first diaphragm to the second diaphragm.

Abstract: A differential pressure measuring transducer assembly of semiconductor material including a pressure receiving section producing a displacement when pressure is applied, and a stationary section of large thickness located at an outer periphery of the pressure receiving section. The pressure receiving section is composed of a large thickness portion extending to the stationary section at the outer periphery, and a small thickness portion occupying the rest of the pressure receiving section, and a gauge resistance is provided to the large thickness portion.

Abstract: A differential pressure transmitter for process fluids is of the kind having a measuring transducer with a closed cell containing a filling liquid and a measuring diaphragm on both sides of which are arranged resistive, capacitive or inductive elements which are capable of converting a diaphragm deflection induced by differential pressure applied to the cell into electrical quantity changes. Inside the cell is provided at least one pressure sensitive component which is subjected to the pressure (s) of the filling liquid and is capable of providing an electrical output in accordance with the pressure values. This component is preferably a pasted carbon resistor, which permits output processed signal compensations in an electronic processing circuit to be made so as to minimize the effects of static pressure changes.

Abstract: A semiconductor differential pressure transducer comprises a pair of pressure receiving chambers at both sides of a pressure receiving part, and a pair of compensating chambers and a pair of pressure measuring chambers which are placed in the pressure receiving part, and the pressure receiving chambers communicate with the pressure measuring chambers through the compensating chambers.

Abstract: A liquid filled pressure transducer which utilizes a self activating lip seal type valve to create a sealed cavity within the transducer to prevent the flow of liquid from behind the pressure diaphragm and thereby prevent distortion of the diaphragm under overload conditions. A mechanical stop prevents excess displacement of the sensor element.

Abstract: A pressure or pressure-difference measuring apparatus having a central pickup body and a pressure sensor device disposed within a measuring chamber, the subchambers of which are connected via connecting canals to antechambers formed between separating diaphragms and the central pickup body, is disclosed. The apparatus also has supplementary diaphragms resting against the pickup body and connected to the connecting canals through supplementary canals. A simplified mechanical design is accomplished by having single supplementary canals, each open to a connecting canal connected to a separating diaphragm, running to the supplementary diaphragm adjacent to the device's opposite separating diaphragm.

Abstract: A beam assembly for a force transducer of the type which includes a tapered beam portion having one or more strain gauges attached thereto. The beam assembly is in the form of a one-piece cylindrical member having an L-shaped slot formed therethrough to define a beam portion to which said strain gauge is attached, and a lever portion. A first force transmitting strut is attached to the beam portion and a second force transmitting strut is attached to the lever portion.

Abstract: Provided is a pressure sensor of semiconductor type, having a semiconductor diaphragm, wherein the diaphragm comprises at least one of thin wall parts and at least one of thick wall parts, and defines therein recesses formed in the lower surface of the diaphragm below the thin wall parts, piezoresistance elements are laid on the upper surface of the diaphragm near the thin wall parts, and a supporting member is sealingly jointed to the thick wall parts at the lower surface of the diaphragm, so that the recesses are sealed and confined so as to prevent high pressure fluid from blowing off when the thin wall part is broken.

Abstract: A pressure sensor converts fluid pressures into electrical signals by the deformation of a diaphragm. The pressure sensor is comprised of a strain gauge which includes resistance body of amorphous metal material which may be formed directly on the diaphragm by means of a physical vapor deposition process.

Abstract: An electrically isolated semi-conductor transducer and method of making the same wherein a unitary piece of silicon material having opposed flat surfaces is carved out about a central portion thereof through one flat surface forming a toroidally-shaped cavity having curved bottom surfaces partway through said material surrounding a push rod having an upper flat surface lying in the same horizontal plane as the remainder of said carved out flat surface. The upper flat surface of the push rod and the curved carved surfaces surrounding the push rod are etched exposing the silicon material. A plurality of strain gages are provided on the opposite flat uncarved surface of said silicon material. These strain gages may include four diffused silicon strain gages at spaced locations along said uncarved surface.

Abstract: A differential pressure sensor (10) adapted specifically for use with vortex shedding flowmeters which can be used in small spaces, uses a bending beam (60) for providing an electrical signal proportional to differential pressures between two oppositely facing diaphragms (40A, 40B). The diaphragms deflect under differential pressure and cause the beam (60) to be bent. The diaphragms have low mass and have a support structure (43) between them, carrying spring clips (50) which load one end of the bending beam (60). The other end of the bending beam (60) is then supported so it cantilevers from its mounting or support (61, 62) and upon movement of the diaphragms under differential pressure the beam (60) will bend. The signal can be derived by using a bending element made of a piezoelectric "bimorph" beam, which provides a voltage output as it bends, a strain gauge sensor on a beam, or an optical sensor, such as a fine fiber which deflects and provides an optical output may be used, as well as similar devices.

Abstract: A transducer operating on the strain gauge principle having integral temperature compensation and calibration resistors is disclosed. In the presently preferred embodiment, a silicon dioxide layer is disposed on a silicon substrate. Platinum alloy strain gauge resistors are disposed on the silicon dioxide layer and form a Wheatstone bridge circuit configuration. Laser trimable chromium nitride, platinum alloy and gold temperature compensation and calibration resistors are formed on the silicon dioxide layer from the same films used to form the strain gauge, adhesion layers, conductors and bonding pads, to permit the transducer to be calibrated such that its electrical characteristics are in conformance to specified tolerances when the transducer is subjected to temperature variations.

Abstract: A pressure sensor comprising a piezoelectric material formed in a geometry which provides a piezoelectric output signal when subjected to a pressure. The piezoelectric material also has a pyroelectric output signal. The present sensor further comprises conductive contacts having a geometry for enhancing the piezoelectric output signal and for substantially eliminating the pyroelectric output signal.

Abstract: A pressure-sensing transducer which can be used to continuously measure the pressure in the cylinder of an internal combustion engine comprising a pressure-transmitting element which includes a generally tubular seat and a metallic plate which closes off a top end of the seat, an M-shaped force-transmitting member which spans across the top end of the seat, the outer legs of the M-shaped member being connected to opposite portions of the top end of the seat and the inner legs being connected to the center of the metallic plate, and a magnetoelastic force-sensing member connected between the outer legs of the M-shaped member, such that pressure-generated forces applied to the metallic plate from within the generally tubular seat are transformed into a tensile force acting on the force-sensing member in a direction perpendicular to the longitudinal axis through the generally tubular seat.