Abstract: A pressure sensing apparatus for operative arrangement within an environment, having: a sensor comprising a hermetically-sealed receptacle, at least one side of which has an flexible membrane to which a magnetically hard element is attached. Enclosed within the receptacle is a magnetostrictive element that vibrates in response to a time-varying magnetic field. Also included is a receiver to measure a plurality of successive values for magneto-elastic emission intensity of the sensor taken over an operating range of successive interrogation frequencies to identify a resonant frequency value for the sensor.

Abstract: A differential pressure detecting system having a compliant first chamber, which is contained within a second environment, in combination with a sensor system for monitoring change in volume/shape of the compliant first chamber. In use the internal volume of the compliant first chamber is caused to access a first environment, so that pressure differences between the first and second environments can be detected via monitoring of change in volume/shape of the compliant first chamber. The compliant first chamber expands when the pressure therein is greater than that in the second environment, but does not expand, or decreases if already expanded, when the pressure in the second environment is equal to or greater than that inside the compliant first chamber. The detector system can be of any functional type that does not significantly affect the compliant first chamber volume/shape by its interrogation thereof in developing a signal.

Abstract: Sensors for mounting in fluid chambers respond electrically to low pressures in the fluid, while resisting damage or leakage at high pressures. A flexible diaphragm, mounted at one end of a housing, is sandwiched between first and second annuli, leaving a center portion free to move in response to fluid pressure changes. The diaphragm moves a cylinder, which reciprocates in the second annulus against an adjustable spring bias. Travel of the cylinder away from the fluid is limited by a stop. Once the stop is reached, increased pressure on the diaphragm forces it against a fixed wall composed of a face of the second annulus and a face of the cylinder. The forces on the diaphragm are then all compressive. This enables the use of an easily flexed diaphragm for low pressure sensitivity, while resisting damage from high pressures. The moving cylinder is used to move a magnet that actuates a Hall effect switch, a Hall effect analog output transducer, or a reed switch.

Abstract: A magnetic pressure sensor for sensing a pressure change inside a sealed container. The sensor includes a sealed deformable vessel having a first end attachable to an interior surface of the sealed container, and a second end. A magnet mounted to the vessel second end defining a distance away from the container surface provides an externally detectable magnetic field. A pressure change inside the sealed container causes deformation of the vessel changing the distance of the magnet away from the container surface, and thus the detectable intensity of the magnetic field.

Abstract: A pressure variation monitoring device adapted to measure pressure variation of an object is disclosed. The monitoring device includes an abutting device adapted to detect the pressure variation of the object to be detected to generate a displacement in response to the pressure variation; a magnet supported on the abutting device to be movable therewith in response to the pressure variation; a coil co-axially surrounding the magnet and allowing the magnet to be movable relative thereto; an oscillation circuit, coupled to the coil to generate an oscillation signal; a signal processing unit for receiving and processing the oscillation signal to provide an output signal; and a display for providing a reading of the pressure variation.

Abstract: A remote pressure or vacuum sensing device including a housing having first and second chambers separated by an internal wall, the first chamber being in fluid communication with a pressurized or vacuum environment to be monitored. An activator assembly is carried within the first chamber for axial movement therein between a terminal position and other positions in response to fluid communication of pressure or vacuum conditions of the monitored environment to a portion of said activator assembly. An activatable assembly is carried within the said second chamber for activation upon movement of the activator assembly from its terminal portion to other positions to provide signals for indicating pressure changes in the monitored environment.

Abstract: In a semiconductor acceleration sensor, a weight and thin beam parts adjacent to the weight are formed on a substrate, a moving electrode is formed on the weight, and a fixed electrode is formed at a position of the other substrate opposed to the moving electrode. Both the electrodes come in contact with each other and conduct as a result of acceleration on the weight, whereby the semiconductor acceleration sensor operates. The fixed electrode or the moving electrode is formed with a projection toward the opposed electrode and the projection and the electrode come in contact with each other and conduct by action of acceleration with a predetermined spacing held between both the electrodes for preventing occurrence of chattering caused by the electrostatic attraction force between both the electrodes.

Abstract: A combination of an in-line pressure sensor and a portable gauge head are arranged such that they can be quickly connected and disconnected together and apart for giving a quick pressure reading of the pressure sensed by the sensor. The in-line sensor is semi-permanently installed in a fluid system. The portable gauge head, during a given use, is releasably connected or coupled to the in-line sensor to detect a message signal given off by the in-line sensor and convert that message signal into a visible indication of the pressure sensed by the in-line sensor. After a given use, the portable gauge head is disconnected or de-coupled from the in-line sensor and is transported elsewhere either for use with another in-line sensor at a different location or else for storage between uses.

Abstract: A differential pressure transducer includes a pair of interior chambers separated by a peripherally supported, nominally planar electrically conductive diaphragm. A magnetic assembly is positioned on at least one chamber wall opposite to a central portion of the diaphragm. The magnetic assembly includes an electrical conductor and preferably a magnetic field permeable electric field shield between the electrical conductor and the chamber so that as the central portion of diaphragm is displaced from its nominal plane in response to an applied pressure differential, the inductance of the magnetic assembly changes. The transducer may be a portion of a tank circuit of an oscillator having a frequency of oscillation that varies with the pressure differential applied across the diaphragm.

Abstract: A pressure detection apparatus including a pressure detection diaphragm, pressure detection circuit for outputting a pressure detection signal proportional to a pressure applied to the pressure detection diaphragm and clamping circuit for clamping the pressure detection signal to a predefined maximum or minimum value when the detected pressure signal is larger than the maximum value or less than the minimum value. Signal clamping by the clamping circuit is cut-off or cancelled when the pressure applied to the pressure detection diaphragm causes an operational error. This operational error may be detected by forming part of the clamping circuit on a semiconductor diaphragm of the sensor. Also, a failure detection circuit may be used to detect sensor failure and then cancel signal clamping.

Abstract: A method for non-invasively monitoring a pressure of a compressed gas inside a closed container includes: forming a magnetic circuit through a portion of the outside wall of the container; detecting magnetic flux amplitude changes in the magnetic circuit created by a transient stress in the outside wall of the container; producing data representing the magnetic flux amplitude changes; and monitoring pressure changes from a nominal pressure by evaluating the data representing the magnetic flux amplitude changes.

Abstract: A high-temperature, integrated, pressure sensor includes a single crystal semiconductor substrate that is provided with a recess in a first surface thereof, the recess bounded by a rim. A first coil structure is positioned within the recess and a pressure diaphragm, comprising a single-crystal semiconductor wafer is bounded about its periphery to the rim of the semiconductor substrate. The bonding is created by a glass interlayer between the pressure diaphragm and the semiconductor substrate. A second coil structure is positioned on the underside of the pressure diaphragm and is separated from the first coil structure. Electrical circuitry is connected to both coil structures and provides an output indicative of changes in inductive coupling between the coils.

Abstract: The invention concerns a method of manufacturing a measuring device of the Fabry-P erot resonator type. The invention likewise concerns a measuring device manufactured by means of the method. The measuring device is particularly intended for measurement of the pressures inside engine cylinders and comprises a cavity and a first part and a second part, said two parts sandwiching the cavity between them. At least the first part, which consists of silicon, supports a spacer layer of silicon dioxide formed through thermal oxidation. The spacer layer which is partially removed through etching, is joined to the second part using the technique known as direct bonding (SDB).

Abstract: A sensing transducer (10,30) and a method therefor uses a Schottky junction (12) having a conductive layer (16) disposed on a semiconductor substrate (14). The conductive layer (16) is generally formed from the reaction of a metal with a portion of the semiconductor substrate (14). One example of the conductive layer (16) is a metal silicide layer. In one pressure sensing approach, a substantially constant reverse current (I.sub.1) is applied to the Schottky junction (12). The change in reverse output voltage of the junction (12) is proportional to the change in pressure on the junction (12) itself, and can thus be used to sense pressure. This output voltage change is significantly higher than that achieved with prior pressure transducers and permits the output signal of the transducer (10,30) according to the present invention to be substantially used without extra amplification or other conditioning.

Abstract: An inductive pressure transducer senses fluid pressure within a tubular member by passing an alternating current within an inductor coil to generate a magnetic field. The magnetic field passes through a gap between the tubular member and the inductor coil, and into an exterior portion of the tubular member. A detector means senses the net energy transferred from the inductive coil by the magnetic field, which indicates the fluid pressure within the tubular member.

Abstract: The invention is a pressure sensor including a main body including a pressure inlet at and end thereof, a deformable section deformed by a pressure introduced through the pressure inlet, and a non-deformable section maintaining the shape thereof even when supplied with a pressure introduced through the pressure inlet; an amorphous magnetic alloy member having a magnetostriction constant, the amorphous magnetic alloy member being adhered on the deformable section and the non-deformable section; a first permeability detection element for detecting the permeability of a part of the amorphous magnetic alloy member corresponding to the deformable section; a second permeability detection element for detecting the permeability of another part of the amorphous magnetic alloy member corresponding to the non-deformable section; and a yoke for covering the first and the second permeability detection elements; the yoke is adhered on the main body.

Abstract: A pressure transmitter converts input pressures on the order of 0.000.15 inch of water column to proportional electrical output signals. A housing defines an open internal chamber and a substantially constant area shaped membrane spans the chamber and is secured about its perimeter thereto, dividing it into a convex side and a concave side. The convex side of the membrane forms an input side adapted to receive an input pressure. A beam is mounted for pivotal movement on the concave side of the membrane. One end of the beam supports a mechanical column which contacts the membrane and asserts a slight upward force on it. The opposite end of the beam mounts a reflector which is mounted directly over a photomicrosensor which outputs a voltage signal proportional to the movement of the reflector. A second photomicrosensor outputs a constant reference output voltage. A comparator receives both photomicrosensor outputs and outputs a voltage signal proportional to the difference therebetween.

Abstract: A system for providing D.C. power at the earth's surface to a downhole well tool in a case hardened side pocket mandrel using an inductive coupling system where the mandrel has a pressure sealed probe member sealingly attached in a side pocket of the mandrel. The probe member extends externally to a cable conductor and is enclosed in a protective housing. A surface located D.C. power source is connected by the cable to a downhole square wave oscillator with a full wave driver to power an inductive coil in the probe member. The end socket of the tool has an inductive coil connected to a full wave rectifier in the tool for providing power to the tool. Pressure sensors in the tool are used to develop frequency shifted key signals to the cable via the inductive coils which provide a digital current modulation and which is detected at the earth's surface.

Abstract: A differential pressure sensor includes a ferrofluid sensing element, or slug, that changes position in a tapered magnetic field in response to a pressure differential. The ferrofluid slug is contained in a tube and moves within the tapered magnetic field, which is perpendicular to the longitudinal axis of the tube. The field has a maximum flux density at its center and tapers off in both axial directions from its center. In response to a pressure differential of zero, the slug is centered in the field. In response to a non-zero pressure differential, the slug moves to the position in the field where the net magnetic forces equal the pressure differential. The position of the slug is sensed by sensing elements which produce output signals that vary according to the position of the slug.

Abstract: A pressure sensor includes a diaphragm having a magnetic film fixed to one side thereof. The diaphragm is arranged to displace depending on a pressure differential applied thereacross to change an inductance of a coil which is arranged close to the magnetic film with a predetermined gap therebetween. An alternating current is supplied to the coil to be modulated by the inductance of the coil so that the pressure differential across the diaphragm is converted into an electric signal. A monitored pressure is derived based on this converted electric signal.

Abstract: In a bridge circuit of a pressure sensor, resistances are connected in series to the impedances of a pressure detection coil and of a dummy coil for differential provided for deforming and non-deforming parts, and the values of the resistances are smaller than the impedances of the coils. The inductance and the internal resistance of the coils are measured under zero pressure and under the highest rating pressure. The resistance connected to the pressure detector coil is determined so that the sensor output sensitivity, represented as a difference of the sensor outputs under zero pressure and under the highest rating pressure, at the highest temperature agrees with that at the lowest temperature. The resistance connected to the dummy coil is determined so that the sensor output, represented as a difference of the sensor outputs under zero pressure, at the highest temperature agrees with that at the lowest temperature.

Abstract: A pressure sensor in which a magnetostriction effect of an amorphous magnetic alloy is utilized. It is an object of the invention to suppress the thermal sensitivity change of the pressure sensor and to improve the lineality and the hysteresis of sensor output. The pressure sensor comprises a cylindrical columnar hollow body with a pressure introducing opening, a deforming part of which body is distorted by a pressure introduced from the pressure introducing opening, the deforming part being a peripheral wall of the body, and a thin film made of an amorphous magnetic alloy having a magnetostriction property which is fitted around and bonded to the deforming part, wherein the film, which is curved to have a cylindrical shape and annealed before it is provided around the cylindrical columnar deforming part, has a curvature different from a curvature of the cylindrical columnar deforming part.

Abstract: A sensing system including a sensing device with cooperating electrical components which move relative to each other in response to a sensed environmental parameter to yield a reactance signal, which is transmitted to a remotely located processor having an oscillator for receiving the transmitted signal and generating a transduced signal whose value corresponds to the value of the environmental parameter.

Abstract: The pneumatic pressure in a tire on a wheel of a vehicle is introduced into a pressure chamber positioned at a central axis about which the tire is rotatable through a communication passage defined in the wheel. When the pneumatic pressure in the pressure chamber varies, a diaphragm or bellows attached over the pressure chamber is elastically displaced, axially moving a slide bar extending axially through a wheel shaft on which the wheel is supported. The movement of the slide bar displaces a ferromagnetic member in a coil, whose inductance then varies. The change in the coil inductance is detected by an electronic control unit, which transmits a signal to a display unit.

Abstract: A pressure sensor has a recess formed in outer surfaces of a deforming part and a non-deforming part such that a pair of steps are formed at opposite ends of the recess. The deforming part is strained by a pressure whereas the non-deforming part is not strained by the pressure. An amorphous magnetic alloy film is received in and affixed relative to the recess, and extends between the pair of steps. The depth of the recess is larger than the thickness of the film. A pair of permeability detector elements are mounted respectively on the deforming part and the non-deforming part so as to detect a change in permeability of the film.

Abstract: An apparatus for measuring small displacements, either linear or angular, employ a pair of spaced "barber pole" or other magnetic field sensitive elements and a movable magnet, in which the exact position of the movable magnet is determined from the voltages sensed at the two elements. The voltages are evaluated in a circuit which produces a rectangular voltage or equivalent, in which the mark/space ratio equates to the position of the magnet between the two sensors.

Abstract: A tensioned bellows pressure transducer having a pressure chamber [40], an elastic vibrating member [50], an electromagnetic coil [60] a linkage [33], a rigid body [30], a body extension [35], and a pressure deformable member [22] defining in part a reference chamber [20]. In preferred embodiments, the pressure deformable member is a bellows. Bellows [22] is attached at bellows fixed end [23 to rigid body [30] and is deformable in response to a difference between a bellows internal reference pressure p.sub.0 and any pressure p.sub.1 external to bellows [22], such as in pressure chamber [40]. Elastic vibrating member [50] is connected at a first end to linkage [33]. Linkage [33] projects rigidly from an interior face of bellows free end [24] and vibrating member [50] is connected to linkage [33] at a distance d.sub.2 from free end [24], and is connected to body extension [35] at a distance d.sub.1 from free end [24], where d.sub.1 is less than d.sub.2.

Abstract: An automatic transducer selection system for fluid pressure measurement functions by using two or more transducers with different ranges of accuracy and also by incorporating comparator circuitry which automatically selects the transducer reading nearer to full scale. An electronic signal or output from the comparator is preferably nested such that a continuous voltage is generated in accordance with the fluid pressure being measured, thus making the system appear to function as a single transducer with a wide range of accuracy.

Abstract: A detector for a blocked condition in a tube of a liquid infusion pump includes a moveable shaft which is kept in contact with the outer wall of a flexible tube for transporting a liquid therethrough and moves according to the changes in the outer diameter of the tube corresponding to changes in the internal pressure of the liquid. A magnet core is affixed to this shaft and affects the inductance of a solenoid coil which is affixed at a fixed position. A blocked condition in the tube is detected by monitoring the change in the inductance of this coil.

Abstract: A pressure sensor having the structure wherein an amorphous magnetic alloy member or members are secured to both of a deforming part which is distorted by a pressure and a non-deforming part which is not distorted by a pressure and elements for detecting the change of a permeability of the amorphous magnetic alloy are respectively disposed at each of the amorphous magnetic alloy members, can measure the magnitude of an applied pressure with high accuracy while suppressing a drift of the output accompanied with the change of a temperature.

Abstract: A Hall effect pressure transducer incorporates a pressure-deflection diaphragm which has patterned depressions therein to enhance linearity of response; an O-ring diaphragm seal which seals the diaphragm against pressure leaks without affecting the linearity of response; a pair of magnets, preferably rectangular, oriented with their North-South axes oppositely parallel, and oriented transverse to the deflection axis of the diaphragm to provide a uniform magnetic field gradient and sensitive, accurate, linear response of the transducer to either positive or negative pressure-induced deflections of the diaphragm.

Abstract: An electrohydraulic device is suggested for continuously monitoring the pressure in a hydraulic brake system for automotive vehicles, in particular for outputting electric control signals in dependence upon applied pressure signals, the said device being composed of a housing containing two coaxial bores, a receiver arranged in the housing and applicable by the inlet pressure, as well as a converter for converting the hydraulic pressure into an electric output signal.To devise a structurally simple, reliable device of cost-efficient manufacture, the instant invention provides that the receiver is formed of a membrane made of amorphous metal with changing permeability which coacts with a coil system used as a converter, the output signals of which can be supplied to an evaluating electronic system.

Abstract: The pressure sensor has a mechanical pressure receiving member and a mechanical-electrical transducer connected to it. The transducer comprises a permanent magnet attached with a moving portion of the pressure receiving member which cooperates with a locally fixed Hall-effect sensor mounted on the housing. To linearize the characteristic response curve of the transducer the inner surface of the housing wall is shaped like a funnel in a region between the permenent magnet and the Hall-effect sensor and in the vicinity of the permanent magnet. Because of this geometry the field strength lines are bunched increasingly on increasing separation of the permanent magnet from the Hall-effect sensor so that the field strength at the Hall-effect sensor increases and/or decreases approximately linearly with displacement path of the magnet.

Abstract: A medical infusion pump includes a housing (10), a pump assembly (30), a bubble sensor assembly (120), a pressure sensor assembly (140) and a flow control assembly (180). The pump assembly includes a ring (26) with teeth (44) and a wheel (46) mounted for eccentric rotation within the ring. The pumping action is developed by the rotation of the wheel which continuously closes a portion of tubing (36) against one or two teeth as it goes through the pumping cycle. The bubble sensor includes a pair of sensor blocks (124) defining a generally V-shaped trough for cradling a portion of the tubing. The pressure sensor assembly detects pressure variations by movement of a diaphragm (168) coupled to a magnet (162) which is operatively coupled to a Hall effect circuit (160). The flow control assembly includes a thumb wheel (196) having a cam groove (197) interacting with a valve stem (199) for controlling the fluid flow through an orifice and associated valve seat (194).

Abstract: The pressure measuring device has a housing in which a pressure chamber is located in a pin extending freely in the interior of the housing from a base. The pressure chamber wall is deformable elastically under an applied pressure. In the free end portion of the pin a magnetoresistive sensor is mounted which is moved with the chamber wall in a displacement occurring because of pressure changes in the chamber and thus is displaced relative to a permanent magnet. The magnet is mounted slightly transversely in the end portion of a compensating sleeve which surrounds the pin with wall contact. The change of the magnetic field at the sensor on displacement causes a proportional resistance change of the sensor so that an electrical signal proportional to the pressure change is generated which is a measure of the pressure. An amplifier for the signal from the magnetoresistive sensor can be mounted inside the housing adjacent the permanent magnet or the magnetoresistive sensor.

Abstract: A pressure transducer suitable for use in high temperature environments includes two pairs of induction coils, each pair being bifilarly wound together, and each pair of coils connected as opposite arms of a four arm circuit; an electrically conductive target moveably positioned between the coil pairs and connected to a diaphragm such that deflection of the diaphragm causes axial movement of the target and an unbalance in the bridge output.

Abstract: The long-term measurement stability of a magnetostrictive effect strain or stress sensor that uses an amorphous magnetic alloy excited by a magnetic field is improved by generating a magnetic field from an electric current formed from a superposed alternating current waveform and a recurring rectangular current waveform that has a larger amplitude at its start-up and which converges to a smaller amplitude after a predetermined time period or an electric current formed from a superposed direct current component and an alternating current component having constant amplitude and a frequency that varies in a recurring manner between a high frequency and a lower frequency.

Abstract: An on-board tire pressure indicating system comprises for each tire of a vehicle, a receiver disposed adjacent the rotating wheel on which the tire is mounted. On the wheel is a transmitter which comprises three magnets, spaced apart in a general circumferential sense, and lying on essentially the same radius. As the wheel rotates, the magnets repeatedly sweep past the receiver, which generates a pulse at the passage of each magnet. Two of the three magnets are disposed in a predetermined fixed circumferential spacing on the wheel. The third magnet is selectively positioned in a circumferential sense relative to the other two magnets in accordance with the pressure in the tire. The time between the two fixed magnet pulses corresponds to a reference measurement dimension while the time between the selectively positioned magnet's pulse and the one of the two fixed magnet's pulse corresponds to an inflation pressure measurement dimension.

Abstract: A stress-sensitive sensor comprising a means for generating magnetic flux, a thin sheet of an amorphous magnetic alloy which is located in the magnetic flux and which is physically deformed in response to an external force to be measured, and a means for detecting the physical deformation as a variation of the magnetic flux which depends on the external force. The amorphous magnetic alloy consists essentially of Fe.sub.a Cr.sub.b Si.sub.c B.sub.d, in which a is a value of from 69 to 81.5 atomic percent, b is a value of from 2.5 to 6 atomic percent, c is a value of from 10 to 15 atomic percent, and d is a value from 6 to 10 atomic percent provided that a+b+c+d=100. The sensor is particularly suitable for oil pressure or torque detection.

Abstract: A pressure responsive switch of the amorphous diaphragm type in which an orifice plate having an orifice for passing a pressure medium and an amorphous diaphragm which receives the pressure of said pressure medium are mounted in a case so that they are slidable along an inside surface of said case, whereby the amorphous diaphragm is not subjected to any binding effect of the case.

Abstract: A fluid pressure sensor includes a body made of a soft magnetic material with a groove formed therein, and a coil is installed in the body in the groove. One magnetostrictive disc is placed on the body over the groove, and two non-magnetic discs are placed over the magnetostrictive disc. A casing is provided for accommodating the body carrying the coil, the magnetostrictive disc, and the non-magnetic discs, and it is closed by a lid member which has a surface for receiving a fluid pressure. A plurality of through holes are formed in the lid member within the fluid pressure receiving surface such that the through holes extend to the non-magnetic disc at position over the groove, whereby the magnetostrictive plate is partially distorted by the fluid pressure.

Abstract: A four-active-arm variable-reluctance transducer which provides a high-level output signal, enabling detection and measurement of minute variations of the measured parameter while that parameter is at a high level relative to the full-scale performance capability of the transducer.

Abstract: A pressure transducer of the type providing a continuous electrical output signal indicative of the variation in sensed pressure having a metallic preferably aluminum armature attached for movement with a resilient pressure responsive diaphragm. A resonant circuit includes a coil disposed adjacent the armature and an oscillator provides current flow in the coil which generates eddy currents in the armature; and, movement of the diaphragm and armature causes the eddy currents therein to alter the effective inductive reactance of the coil and shift the frequency of resonance of the circuit. Circuit means are provided to emit an output signal indicative of the frequency shift for enabling a continuous determination to be made of the sensed pressure on the diaphragm. An auxiliary snap-action switch is provided remotely from the diaphragm and is actuated by a non-metallic rod from the armature passing through the central region of the coil. The circuitry is preferably mounted on a p.c.

Abstract: Parameter sensors and monitors are described incorporating one of a variety of parameter responsive structures constructed and arranged for expansion and contraction causing a component of motion and displacement along at least one direction in response to variations of a selected parameter. A reference mounting supports the parameter responsive structure and either a magnet element or Hall effect transducer is secured relative to the reference mounting or housing in alignment with a selected direction of a component of motion and displacement caused by expansion and contraction of the parameter responsive structure. The other of said magnet element and Hall effect transducer is mounted for relative displacement along said selected direction in response to expansion and contraction of the parameter responsive structure.

Abstract: A diaphragm arranged between two pressure chambers is coupled through a diaphragm plate to a leaf spring. The leaf spring is fixed at one end and is provided with an actuating boss. A free end of the leaf spring serves as an armature which cooperates with a measurement transducer operating on the contactless principle. The measurement transducer delivers a constant electrical output signal as the input signal of a constant regulator or, alternatively, for switching a two-threshold regulator. Due to the low mass of such a leaf spring, the sensor incorporating the transducer is largely independent of orientation and insensitive to mechanical shock.

Abstract: A pressure-measuring transducer device for transforming a change of tested pressure into a change of output signal frequency. Variable reluctance sensing elements and an FM IC block are assembled together in a base. The transducer device can have a variety of configurations and external forms and is sturdy and reliable, tightly sealed, interference resistant, and adapted for use in measuring dynamic and static pressures of different mediums. The pressure transducer has a piston type double film, and the base is made of aluminum alloy and is "honeycombed". The specific gravity is approximately equal to that of soil. It is adapted for measuring soil pressure or boundary soil pressure of reinforced concrete structure and pressure of loose solid substances. An alternate embodiment is used for measuring pore pressure in soil. Several forms of filtering devices are provided.

Abstract: A manometer device for continuous monitoring of the air pressure in vehicle tires is described which consists of a manometric capsule and an electrical indicator device associated therewith. A flatly conical membrane with a cylindrical projection is arranged transversely through the interior space of the manometric capsule. A permanent magnet is inserted in this projection. The membrane divides the interior space of the manometric capsule into two chambers, of which one chamber is stressed with a nominal pressure and the other chamber is connected to the pressure space of a vehicle tire. A stationary sensor, which is associated with the manometric capsule to be mounted on a rim flange, responds to linear magnetic field variations and transmits the latter to a terminal.

Abstract: A position and motion transducer is described comprising means for providing a permanent magnetic field adjacent an appropriately oriented toroidal transformer, which can be either an isolation transformer or an autotransformer. The means for providing a permanent magnetic field, in an especially useful embodiment is a permanent magnet cobalt disk magnet with its surface pole facing generally radially in the plane of the torus or generally perpendicular the axis thereof. Appropriate excitation of one winding of the toroidal transformer enables readout equipment connected with the other winding to indicate the position and movement of the magnet relative the toroid. Appropriate mounting of the magnet enables various measurands to be indicated. For example, mounting the magnet on or for movement with a diaphragm enables fluid pressures applied thereto to be measured while mounting the magnet on a spring support force plate or piston/cylinder enables the force or weight applied thereto to be measured.

Abstract: A pressure sensor having the structure wherein an amorphous magnetic alloy member or members are secured to both of a deforming part which is distorted by a pressure and a non-deforming part which is not distorted by a pressure and elements for detecting the change of a permeability of the amorphous magnetic alloy are respectively disposed at each of the amorphous magnetic alloy members, can measure the magnitude of an applied pressure with high accuracy while suppressing a drift of the output accompanied with the change of a temperature.

Abstract: An automatic transducer selection system for fluid pressure measurement functions by using two or more transducers wtih different .Iadd.measurement .Iaddend.ranges .[.of accuracy.]. and also by incorporating comparator circuitry which automatically selects the transducer reading nearer to full scale. An electronic signal or output from the comparator is preferably nested such that a continuous voltage is generated in accordance with the fluid pressure being measured, this making the system appear to function as a single transducer with a wide .Iadd.measurement .Iaddend.range of .Iadd.high .Iaddend.accuracy.