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: An apparatus comprising a chemically sensitive sensor material, having an electrical resistance or dielectric constant which changes under the effect of the gases or vapors. According to the invention, this sensor material, which comprises either hydrophobic metal complexes, or a mixture of at least one phthalide and at least one acidic compound, serves as resistance or as dielectric material. These sensor materials change their ion mobility and/or their ionic concentration under the effect of gases or vapors, thereby changing their resistance or capacitance. The change in resistance or the change in capacitance can expediently be converted into a frequency change by a multivibrator. Thus, one obtains an especially simple and very effective sensor for gases and vapors.

Abstract: A sensor chip subassembly for use in a transducer assembly includes a support member to which a pressure sensitive chip is elastically bonded at predetermined but spaced points to separate the chip from direct contact with the support member. The separation minimizes vibration and stress from being transmitted from the support member to the chip.

Abstract: A pressure sensor including a ceramic diaphragm which is deformable in response to a pressure applied thereto, a ceramic base associated with a periphery of the ceramic diaphragm, for supporting the ceramic diaphragm, and at least one resistor formed on the ceramic diaphragm. Resistance value of the resistor are adapted to vary depending upon a magnitude of deformation of the ceramic diaphragm, and thereby represent the pressure applied to the ceramic diaphragm. The ceramic diaphragm and the ceramic base consist of a co-fired body obtained by co-firing an unfired diaphragm member and an unfired base member.

Abstract: A pressure sensor in which a Ni-Si-B amorphous alloy strain gauge is covered and protected from the external impact and dust in the air by a protective film.

Abstract: A solid state gas pressure sensor has a resistor of polysilicon deposited upon a dielectric substrate which electrically isolates and thermally prevents heat transfer to other devices thereon. A constant voltage is applied to the resistor. Depending upon the gas pressure over the sensor, a given current will be output once temperature equilibrium is established. A change in the gas pressure changes the output current of the resistor. The output current indicative of pressure is temperature corrected.

Abstract: An innput/output terminal assembly for pressure transducers of the flexure type. The transducer includes a flexure member which senses an applied pressure by means of strain gauges mounted thereon. A known problem with such an arrangement concerns the electrical connections to the strain gauges wherein there is conflict between the flexible connections required to accommodate flexure displacement and the rigid connections required to lead away from the gauges since a pressure chamber must be spanned. Previously this conflict has been resolved by bonding an insulative terminal plate proximate the flexure to provide a junction between flexible and rigid conductors. Such an arrangement gives rise to problems of construction rigidity and performance if excess bonding resin contacts the flexure. The invention provides a welded terminal plate, which is insulative by virtue of a thick film layer of glass, on which electrical connection may be made to areas of thick film gold.

Abstract: Differential transducers for corrosive or electrically conductive fluids have a first tube for guiding such fluids toward one side of a semiconductor diaphragm containing embedded strain gages, and a second tube for guiding such fluids toward an opposite side of that semiconductor diaphragm. These tubes are made of an electrically insulating material temporarily convertible to an electrical conductor for electrostatic bonding. The semiconductor diaphragm is provided in a semiconductor wafer extending beyond the perimeter of at least the first tube. The strain gages are provided with embedded electrical leads extending beyond the above mentioned perimeter for attachment of electrical contact wires outside the first tube, while providing these leads inlaid in the semiconductor wafer at least in a region to be covered by the first tube.

Abstract: A semiconductor pressure sensor wherein a semiconductor chip of diaphragm type is supported by a mount plate through a thin tubular supporting member or a pressure inlet tube having a coefficient of thermal expansion similar to that of a substrate constituting the semiconductor chip. The semiconductor chip is fixed to the thin tubular supporting member or the pressure inlet tube by means of a bonding material, and the thin tubular supporting member or the pressure inlet tube is fixed by means of a bonding material having a high bonding strength with respect thereto, thus absorbing thermal stress produced due to the difference in coefficient of thermal expansion.

Abstract: An oxygen sensor which exhibits a change in electrical resistance as a function of oxygen partial pressure, comprises at least one of strontium ferrate (SrFeO.sub.3-x), barium ferrate (BaFeO.sub.3-x), and strontium barium ferrate (Sr.sub.1-b Ba.sub.b FeO.sub.3-x), where x is a variable and determines the degree of oxygen deficiency of the oxide, and b is 0 to 1, in which part of the iron in the ferrate lattice has been replaced by at least one element selected from the group consisting of zirconium, hafnium and tin.

Abstract: A flange provided on a tubular metallic member coupled by glass bonding to the glass base to which the strain guage is fixed is made to contact with a receptacle step formed in a housing section of a housing, while pressurizing a metal ring in the housing section to cause plastic deformation of a part of the ring material into a coupling groove formed in the inner peripheral surface of the housing section, thereby coupling the metal ring and the housing.

Abstract: In a differential pressure transducer having isolation diaphragms on opposite sides of a sensing diaphragm, the isolation diaphragms are made highly compliant, are radially prestressed and are bowed outwardly relative to closely spaced backup surfaces by oil pressure. Using very small interior cavities and a substantially stiffer sensing diaphragm differential process pressures induce linear deflection of the sensing diaphragm.

Abstract: In a semiconductor pressure transducer in accordance with the present invention, an oxide film is formed on a semiconductor base having a strain gauge resistor element for the purpose of protecting the strain gauge resistor element. Over the oxide film, a conductive metal film is formed which does not overlap with the strain gauge resistor element through said oxide film.

Abstract: To provide an unyielding support surface for a film-type, typically thick-film resistor (10) made of pressure-responsive resistance material, an unyielding pressure-tight mass of insulating material, for example a melt of glass, ceramic, or suitable plastic, is introduced into a wall portion of a wall element (11) in which a fluid pressure medium, such as high-pressure fluid for injection to a Diesel engine, is retained. The insulating mass is, preferably, formed as a plug element, for example retained within a metal screw which, simultaneously, can form a venting screw for the fuel injection system. One or two electrical conductors (12, 13) pass through the plug element, which if a metal screw, surrounds the insulating mass, the resistance element can extend over the edge of the metal which, then, can form a ground or return connection.

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: The present invention relates to a piezoresistive gauge. This gauge comprises a support, on which are formed two pairs of electrical contacts, partly covered with a piezoresistive element, made from an electricity-conducting organic compound, chosen from among the salts of tetramethyl-tetrathiofulvalene, quaternary ammonium salts of tetracyanoquinodimethane and diethyl-dimethyl-tetrathiofulvalene-tetracyanoquinodimethane (DEDMTTF-TCNQ).This gauge can be used for measuring pressures of approximately 500 bars to a few kbars.

Abstract: A probe for measuring electrical conductance to determine water concentration in a fluid is disclosed. The probe comprises a pair of spaced apart electrodes and a bridge of protein gel between the electrodes. The probe is especially useful for monitoring water concentration in the lubrication oil for a compressor drive train of a hermetic vapor compression refrigeration system. In such a refrigeration system the water concentration in the lubrication oil corresponds to water concentration in the refrigerant of the refrigeration system.

Abstract: A pressure transducer is disclosed having a potentiometer including a resistor and relatively movable conductive wiper and a pressure sensor responsive to a variable pressure signal to move the wiper along the resistor so as to convert the variable pressure signal into a variable voltage signal. The resistor is mounted in conductive relationship in the potentiometer and so as to be slidably adjustable external to the transducer and relative to the wiper to thereby enable ready calibration of the voltage signal with respect to the pressure signal.

Abstract: A pressure unit assembly for providing an electrical signal representative of sensed pressure, for example an oil pressure unit assembly for an automobile engine. The unit is adapted for fabrication by automated equipment and it makes efficient use of constituent materials. Novel features of the unit include its spring contact element, its resistive element, and its electrical terminal configuration.

Abstract: A Hall-effect sensor unit producing an electrical output is located between two permanent magnets of opposed polarity. The magnetic induction detected by the sensor unit is caused to vary with the pressure by variation of the spacing between the sensor unit and one or both magnets, or by variable introduction of a magnetically soft member between the sensor unit and one of the magnets, the motion being produced in each case by a membrane or a variable volume chamber which produces displacement in proportion to gas pressure to be sensed. The force converter is particularly designed to provide a highly linear pressure measurement signal for the air intake condition of an internal combustion engine.

Abstract: A signal transducing apparatus comprising first and second elements movable with respect to each other and each having first and second ends and a conductive path, the conductive paths of the elements electrically contacting each other at a location which is displaced along their paths with the relative movement of the elements. A spring unit movably retains the second element having a first end fixed with respect to the first element and a second end secured with the second end of the second element, the spring unit urging the second end of the second element in a predetermined direction with respect to the first element and urging the first end of the second element in the direction toward the first element.

Abstract: A pressure transducer incorporates a tubular body symmetrical in two transverse directions, and two pairs of diametrically opposed active strain gages secured to a single surface of the body at equally spaced locations which maintain mechanical and electrical two-fold symmetry, oriented to respond to transverse tangential bending strain in the wall of the tubular body. The four strain gages are connected in a four-legged bridge circuit, which produces a large amplitude linear output signal which is compensated for first and second order errors, without hysteresis. The transducer has a very large safety factor against rupture and may be used in line with a conduit without impeding fluid flow. It is usable for all pressure ranges down to cryogenic temperatures, and may be welded in place with no seals as part of a conduit. It is highly sensitive, with improved resolution.

Abstract: A movable member pressure transducer is disclosed which incorporates various thermal and manufacturing tolerance compensation features. These include a temperature compensating bimetal interposed between the movable member and the pressure sensing aneroid; a threaded engagement between a potentiometer wiper contact and a movable member used to generate an electrical signal corresponding to the position of a lower member, with the threaded engagement allowing adjustment of the zero position of the wiper contact with respect to the potentiometer resistive element; a cantilevered spring is mounted in contact with the free end of the movable member. The cantilever spring mounted in a holder is constructed of a material selected to have a coefficient of thermal expansion compensating for variations in sensitivity due to temperature changes by corresponding changes in the effective lever arm of the cantilever spring by shifting the point of contact of the end of the movable member with the cantilever spring.

Abstract: A contactless switch element for electric currents, which is constructed as a hydrogen-diffusion-impervious but electrically non-conductive, encapsulated metal adapted to be reversibly hydrogenated or dehydrogenated.

Abstract: A pressure transducer comprised of a piezoresistance bridge on a semiconductor chip is employed as a pressure sensor in musical instruments having an air column through which pressure variations pass in producing sounds, such as in wind instruments and drums. A noiseless voltage preamplifier couples the transducer to a power preamplifier the output of which may then be amplified in a conventional audio amplifier. In the case of a wind instrument, the transducer is mounted between the cup or reed of the mouthpiece and the first key or finger hole, or in the air column in a direction opposite the first key or finger hole in the case of a transverse flute or similar reedless woodwind instrument for direct communication with the air column of the instrument.

Abstract: A pressure responsive sender whose electrical resistance varies in response to variations in sensed pressure, adapted to be inserted in series with a voltage source and a pressure indicating gauge, such as an oil pressure indicating gauge. The sender includes a pressure sensing diaphragm coupled to a contact assembly which electrically engages a variable resistor assembly to an extent which is a function of the sensed pressure so that a predetermined electrical resistance for a particular sensed pressure is obtained. A dual stage spring system is associated with the pressure sensing assembly providing increased sensitivity in a low pressure range, a well-defined cut-off pressure and accurate calibration of the sender. The resistor and contact assemblies are pivotally mounted in a manner such that hysteresis problems, i.e., obtaining slightly different resistance values for identical pressures after cycling, are eliminated.

Abstract: Disclosed is a pressure-sensing transducer in which a transducing unit comprising a semiconductor-type strain element is confined within a housing defining a generally funnel-shaped chamber. The unit is supported within the housing in spaced relationship with the surface of the chamber by an electrically non-conductive cup-shaped member of relatively rigid material, and a resilient electrically non-conductive ring which is yieldably deformed by sealing engagement of outer peripheral surface portions of the ring with the chamber and the inner cup surface of the member, and the inner periphery of the ring with the outer circular surface of the unit. A viscous flow-resistant, electrically non-conductive liquid occupies any open space in the chamber for communicating pressure from a pressure source through the small end of the chamber to the element within the unit.

Abstract: A transducer wherein a brush arm is supported for pivotal movement of its distal end along a bank of terminals in a circuit where there is a common terminal and a bank of terminals by expansion and contraction of a bellows. Brushes at the proximal and distal ends of the brush arm are yieldably held engaged with the bank of terminals at the distal end and the common terminal at the proximal end for adding resistances to and removing resistances from the circuit in proportion to changes in pressure. The bellows is supported in a capsule for linear expansion and contraction and contains an open end for receiving, a plug mounting the circuit, brush arm, and linkage as a unit, into operative relation to the bellows, said linkage providing for converting the linear movement of the bellows to rotational movement of the brush arm and for adjustment of the range of movement of the brush arm along the bank of terminals.

Abstract: A transducer of an H-shaped cross section employs a depression relatively equal to the line width of a diffused piezoresistor located in said depression. The depression is sealed by means of a glass member which acts as a "stop" for the transducer for all forces in excess of a rated force which causes a maximum diaphragm deflection relatively equal to the depth of said depression as selected in accordance with said resistor line width and the overall diaphragm diameter.

Abstract: Liquid level detection apparatus and other apparatus comprising in common an elongated flexible substrate transducer which can extend into a liquid containing vessel or be applied to other pressure or force measurement tasks and provide an accurate indication of liquid level or other pressure or force related parameter through a voltage drop measurement made through an elongated, e.g., sinuous or other regular pattern (or of irregular patterning to localize areas of highest sensitivity) conductor pattern contained in the transducer which is shorted out in the portion thereof subjected to a predetermined pressure, the elongated conductor being on facing portions of a folded sheet substrate material which has an inherent spring characteristic (resilience) and/or geometrical-arrangement-loading such that the portion thereof subjected to such pressure has butting face portions and the portion thereof not subjected to such pressure is separated due to the spring characteristic of the folded sheet material.

Abstract: A force measuring beam assembly for use in pressure transducers, accelerometers, load cells, or the like, is symmetrically and floatingly mounted by means of a pair of thin torsionally flexed elements which are positioned in planes perpendicular to the plane of the beam and connect diametrically opposed corners of the beam to a rigid supporting base member in such manner that the beam may be deflected in proportion to movement of the center of the beam and provide an extremely accurate and linear output signal by means of strain gauge elements secured to the beam.In one embodiment a transducer for measuring fluid pressure over a wide range of values includes a diaphragm which is concentric with the force measuring beam assembly. A rigid connection is provided between the center of the diaphragm and the center of the beam so that non-linearity effects are avoided.

Abstract: A flow sensor for producing an electrical signal dependent upon fluid flow has a housing insertable in a bore extending transversely to and intersecting a flow passage in a port plate. A flap pivoted to the housing about an axis transverse to the flow passage is biassed by spring means into a resting position in which the flow passage is obturated. Pivotal movement of the flap from its resting position by fluid flow in the flow passage is converted into an electrical signal by a transducer, such as a potentiometer whose slider is coupled to the flap.

Abstract: A wire wound resistor is vertically disposed in a vessel. The resistor has a former of between 20 mm and 45 mm diameter and resistance wire of a resistance of between 1 and 4 ohms per turn connected in the circuit of an A.C. bridge-circuit. Impedance change is indicated on a display unit calibrated to indicate the change in level of liquid e.g. milk in the vessel. The resistance wire is laid on the former by applying ultrasonic sound energy to soften the former which is of polysulfone or polycarbonate and the wire embedded in the softened former material. The vessel is shaped at the lower end to assist in giving linear readings when the level of liquid is low.