Abstract: A submersible pump assembly (1) includes a submersible pump (2) with a housing (3), and a sensor capsule (4) with a hermetically sealed casing (5). The sensor capsule (4) is releasably mountable at a sensor position (6) located at an outer face (7) of the housing (3) of the submersible pump (2). The submersible pump (2) includes a primary coil (8) within the housing (3). The sensor capsule (4) includes a secondary coil (9) within the casing (5). The primary coil (8) and the secondary coil (9) are arranged to be inductively coupled with each other for wirelessly transferring data and/or power through the housing (3) and the casing (5) when the sensor capsule (4) is mounted at the sensor position (6).

Abstract: An oil-fill pressure transducer including a flexible member configured to protect an isolation diaphragm and sensing element. The pressure transducer includes a sensing element mounted to the header, an isolation diaphragm mounted on the front side of the header, and adjacent to the sensing element such that an oil-fill cavity is defined between the sensing element and the isolation diaphragm. The flexible member is disposed adjacent to the isolation diaphragm and a retention member is disposed adjacent to the flexible member. A cavity in communication with the retention member is configured to transmit pressure media to the isolation diaphragm via the flexible member. The flexible member can include thru-holes. The flexible member may compress under an applied positive pressure change. The flexible member may temporarily separate from at least a portion of the isolation diaphragm under an applied negative pressure change.

Abstract: A pressure sensor includes a conductive substrate having a cavity which forms a thin portion that can be deformed by a pressure differential. A magnetic field sensor has at least one coil responsive to a changing coil drive signal and positioned proximate to the thin portion of the substrate that induces eddy currents in the thin portion that generate a reflected magnetic field. Magnetic field sensing elements detect the reflected magnetic field and generate a magnetic field signal. The magnetic field sensor is positioned so that deformation of the thin portion of the substrate causes a distance between the thin portion of the substrate and the magnetic field sensor to change.

Abstract: Methods and apparatuses for measuring static and dynamic pressures in harsh environments are disclosed. A pressure sensor according to one embodiment of the present invention may include a diaphragm constructed from materials designed to operate in harsh environments. A waveguide may be operably connected to the diaphragm, and an electromagnetic wave producing and receiving (e.g., sensing) device may be attached to the waveguide, opposite the diaphragm. A handle may be connected between the diaphragm and the waveguide to provide both structural support and electrical functionality for the sensor. A gap may be included between the handle and the diaphragm, allowing the diaphragm to move freely. An antenna and a ground plane may be formed on the diaphragm or the handle. Electromagnetic waves may be reflected off the antenna and detected to directly measure static and dynamic pressures applied to the diaphragm.

Abstract: A pressure sensor includes a chamber comprising a conductive portion and a deformable portion coupled to the conductive portion and susceptible to deformation in response to a pressure differential between an interior of the chamber and an exterior of the chamber; at least one coil responsive to an AC coil drive signal; at least one magnetic field sensing element disposed proximate to the at least one coil and to the conductive portion of the chamber and configured to generate a magnetic field signal in response to a reflected magnetic field generated by the at least one coil and reflected by the conductive portion; and a circuit coupled to the at least one magnetic field sensing element to generate an output signal of the pressure sensor indicative of the pressure differential between the interior of the chamber and the exterior of the chamber in response to the magnetic field signal.

Abstract: A position sensor includes a target having an electrical conductor having an exterior boundary, a void located at least partially within the conductor, and an opening extending between the exterior boundary of the conductor and the void, wherein the opening interrupts a current path in the conductor around the void.

Abstract: The present subject matter is generally directed to fuel systems for a gas turbine and related methods for monitoring fluid separation in the fuel systems. More particularly, the systems and methods include measuring pressure differentials and comparing the measurements to a predetermined value.

Abstract: A differential pressure sensor includes a containment body defining a first and a second cavity separated by a separation wall; a piston housed slidably in the first cavity and comprising a magnet; a magnetic sensor housed in the second cavity near the separation wall for sensing the axial distance of the magnet from the separation wall; a positioning system housed in the second cavity and having one portion of a first axial end thereof which supports the magnetic sensor and is elastically yieldable in an axial direction and away from the separation wall, the positioning system being structured so that when it is moved towards the separation wall, the magnetic sensor contacts the latter before the positioning system reaches an axial stroke end, said stroke end being reached thanks to the above-mentioned elastic yielding.

Abstract: A pressure transmitter for measuring a pressure of a process fluid comprises a transmitter housing, a pressure sensor, a hydraulic relay system, a ferrofluid and transmitter electronics. The capacitance-based pressure sensor senses the pressure of the process fluid and is disposed within the housing. The hydraulic relay system comprises an isolation diaphragm positioned on an exterior of the transmitter housing, and an isolation tube extending from the pressure sensor to the isolation diaphragm. The ferrofluid is located in the isolation tube to transmit a change in the pressure of the process fluid at the isolation diaphragm to the sensor. The transmitter electronics are positioned within the housing and are configured to receive and condition a pressure signal from the pressure sensor.

Abstract: A method for manufacturing measuring transducers, especially pressure or pressure difference measuring transducers, in which a high degree of quality, safety and accuracy of measurement is achievable with little logistical and manufacturing effort. The measuring transducer has a memory readable and writable via an associated RFID interface, and at least one sensor for registering a physical, measured variable and for transducing such into an electrical variable, wherein the sensor is equipped with sensor electronics, which serves to condition the electrical variable into an electrical measurement signal dependent on the measured variable, and which is equipped with an RFID transponder, via which the sensor is supplied with energy, and via which measurement signals can be read out wirelessly.

Abstract: A system for measuring and converting to an observer intelligible form an internal physiological parameter of a patient. The invention allows transcutaneous telemetry of intracranial pressure via a system which includes a patient implanted sensor module and an external processing module, optically coupled to the sensor module via an external coupling module. A sensor within the sensor module transduces the measured pressure and a near infrared emitter transmits the telemetry when interrogated by the external coupling module. A set of tuned inductor-crystal circuits comprised in part of a cylindrical crystal oscillator whose resonant frequency is sensed by a dipper circuit arrangement is provided. Power for the sensor module is derived inductively through rectification of a transcutaneously-applied high-frequency alternating electromagnetic field generated within the external coupling module.

Abstract: A sensor system includes: an at least partially magnetoelastic deformation element for measuring pressures, caused by a fluid, that are able to be applied to the magnetoelastic deformation element; and a magnetic circuit formed via a magnetic flux feedback and having a sensor unit and an evaluation unit. The sensor unit is positioned at the deformation element and the evaluation unit having an evaluation coil is structurally separated from, yet inductively coupled to, the sensor unit. The sensor unit has a sensor coil positioned on the deformation element and the evaluation unit has the evaluation coil that is inductively coupled to the sensor coil, the sensor coil forms a resonant circuit, using its own parasitic capacitance or using an additional capacitance, which is able to be energized by the evaluation coil in free resonance with strong or weak inductive coupling by a magnetic circuit enclosing the two coils.

Abstract: Disclosed herein are a water level/vibration sensing apparatus and a washing machine having the same. The water level/vibration sensing apparatus includes a housing provided with a pressure chamber communicating with an air inlet, a diaphragm unit moving forward and backward according to the variation of a pressure in the pressure chamber, a core and a coil forming a frequency varied according to the forward and backward movement of the diaphragm unit, and a collision member striking the diaphragm unit according to the movement of the housing. Therefore, the water level/vibration sensing apparatus simultaneously senses the washing water level and the vibration of the washing machine.

Abstract: A pressure detection device includes a buffer member and a sensor assembly. The buffer member is deformable by a pressure change, and includes a plurality of magnets in an evenly dispersed arrangement. The sensor assembly includes at least one magnetic sensor to detect a variation of a magnetic field accompanied by deformation of the buffer member.

Abstract: A volume sensing system for use in determining a volume of a variable volume reservoir can include a lower plunger that can have a first end adapted to move with a bottom of the reservoir. An upper plunger can be slidable relative to the lower plunger. A lower biasing member can be positioned substantially between a base of the reservoir and the upper plunger, and the upper biasing member can be positioned between the upper plunger and an interference member. The upper biasing member can have a predetermined stiffness relative to the lower biasing member such that upon movement of the lower plunger, the upper plunger can move at a predetermined fraction of the amount of movement of the lower plunger, where the predetermined fraction can be determined at least in part by the predetermined stiffness of the upper biasing member relative to the lower biasing member.

Abstract: A modified inductive pressure sensor for detecting operating parameters of an electric household appliance such as a washing or drying machine, provided with a relatively movable component with respect to the carcass (tank or basket), of the type including a rigid casing accommodating a deformable membrane sensitive to hydraulic pressure, a core made of ferromagnetic material and operatively associated to the membrane, and a winding fixed to the casing and operatively coupled to the core to form a variable inductance inductor; wherein a mass is accommodated within the casing and in immediate proximity of said membrane, free to move with respect to the casing in at least one direction corresponding to the axis of the winding.

Abstract: A system for measuring and converting to an observer intelligible form an internal physiological parameter of a patient. The invention allows transcutaneous telemetry of intracranial pressure via a system which includes a patient implanted sensor module and an external processing module, optically coupled to the sensor module via an external coupling module. A sensor within the sensor module transduces the measured pressure and a near infrared emitter transmits the telemetry when interrogated by the external coupling module. A set of tuned inductor-crystal circuits comprised in part of a cylindrical crystal oscillator whose resonant frequency is sensed by a dipper circuit arrangement is provided. Power for the sensor module is derived inductively through rectification of a transcutaneously-applied high-frequency alternating electromagnetic field generated within the external coupling module.

Abstract: A pressure sensor includes a sensor body which is arranged to couple to a process pressure. The sensor body has a magnetic property which changes as a function of pressure applied by a process fluid. A sensor is coupled to the sensor body and is configured to measure pressure of fluid in the sensor body as a function of a change of magnetic property of the sensor body.

Abstract: The present invention relates to a magnet having a linear magnetic flux density, which causes the magnetic flux density thereof to vary linearly and, more particularly, to a magnet having a linear magnetic flux density, in which the shape and magnetization pattern of the magnet are changed so that displacement in proportion to linearly varying displacement from the magnet is more accurately measured using a magnetic flux sensor, thus causing the magnetic flux density to vary linearly (or rectilinearly) according to the displacement. The present invention is configured to have a rectangular shape or a trapezoid shape so that displacement in proportion to linearly varying displacement from the magnet is more accurately measured using a magnetic flux sensor, and is configured such that the value of magnetic flux density varies linearly (rectilinearly) according to the magnetization pattern of the rectangular shape or a trapezoid shape.

Abstract: Provided is a pressure detection device capable of easy installation and removal of a sensor in/from a diaphragm, measurement of a pressure in a wide rage, and manufacture at a low cost while reducing a size. A sensor part (A) has: a magnet (12) being applied with a load produced by pressing of a diaphragm (8); and a magnet cap (11) covering the magnet (12). The diaphragm (8) has an intra-diaphragm magnetic body (9) buried therein. The intra-diaphragm magnetic body (9) has a protrusion part protruding from the diaphragm (8) so as to be in contact with the magnet (12). The magnet cap (11) has an opening part enabling the protrusion part of the intra-diaphragm magnetic body (9) and the magnet (12) to be joined together.

Abstract: A modified inductive pressure sensor for detecting operating parameters of an electric household appliance such as a washing or drying machine, provided with a relatively movable component with respect to the carcass (tank or basket), of the type including a rigid casing accommodating a deformable membrane sensitive to hydraulic pressure, a core made of ferromagnetic material and operatively associated to the membrane, and a winding fixed to the casing and operatively coupled to the core to form a variable inductance inductor; wherein a mass is accommodated within the casing and in immediate proximity of said membrane, free to move with respect to the casing in at least one direction corresponding to the axis of the winding.

Abstract: A system for measuring and converting to an observer intelligible form an internal physiological parameter of a medical patient. The invention allows transcutaneous telemetry of the measured information intracranial pressure via a system which includes a patient implanted sensor module and a processing and display module which is external of the patient and optically coupled to the sensor module via an external coupling module. A sensor within the implanted module transduces the measured information and a near infrared (NIR) emitter transmits this telemetry information when interrogated by the complementary external coupling module. Alternately, a set of tuned inductor-crystal circuits versus inductor-crystal comprised in part of a cylindrical crystal oscillator whose resonant frequency is sensed by a dipper circuit arrangement is provided.

Abstract: A machine for plasma treatment of containers, including a chamber for receiving a container to be treated, the chamber connected to a primary vacuum circuit. A pressure sensor is connected to the chamber. There is a first mechanism for communicating the pressure sensor with the chamber; a secondary vacuum circuit dependent on the first circuit and connected to the pressure sensor; and second mechanism for communicating the pressure sensor with the secondary vacuum circuit.

Abstract: A method for manufacturing measuring transducers, especially pressure or pressure difference measuring transducers, in which a high degree of quality, safety and accuracy of measurement is achievable with little logistical and manufacturing effort. The measuring transducer has a memory readable and writable via an associated RFID interface, and at least one sensor for registering a physical, measured variable and for transducing such into an electrical variable, wherein the sensor is equipped with sensor electronics, which serves to condition the electrical variable into an electrical measurement signal dependent on the measured variable, and which is equipped with an RFID transponder, via which the sensor is supplied with energy, and via which measurement signals can be read out wirelessly.

Abstract: The pressure detection device includes a buffer member deformable by a pressure change, including one or more magnets, and a sensor assembly including one or more magnetic sensors to detect a variation of a magnetic field accompanied by deformation of the buffer member.

Abstract: The present invention relates to an apparatus for measuring pressure inside a vessel using a magnetostrictive acoustic transducer. The apparatus includes a magnetostrictive acoustic transducer, including an exciting coil unit wound on a first magnetization yoke disposed on an outer position of a vessel, a receiving coil unit wound on the first magnetization yoke, and a vibration unit disposed on an inner position of the vessel in which the first magnetization yoke is installed; a control unit for supplying a predetermined excitation current signal to the exciting coil unit; and a pressure measuring unit for measuring an internal pressure of the vessel based on an ultrasonic wave signal received by the receiving coil unit and an excitation current signal into the exciting coil unit.

Abstract: A pressure sensor includes a sensor body which is arranged to couple to a process pressure. The sensor body has a magnetic property which changes as a function of pressure applied by a process fluid. A sensor is coupled to the sensor body and is configured to measure pressure of fluid in the sensor body as a function of a change of magnetic property of the sensor body.

Abstract: A pressure sensor includes a fill tube which is arranged to couple to a process pressure. A sensor is coupled to the fill tube and is configured to measure pressure of fluid in the fill tube as a function of a change of a physical property of the fill tube. Circuitry is provided to measure pressure using the pressure sensor, and to measure pressure based upon the change of the physical property of the fill tube.

Abstract: An analogue position transducer, usable for example as a pressure switch in a household appliance, includes a rigid casing accommodating a deformable membrane sensitive to hydraulic pressure, a first element engaged to the membrane so as to be mobile along with at least one portion of membrane in a predetermined direction (A), and a second element fixed to the casing and operatively coupled with the first element to provide a signal variable according to the relative position of the first element with respect to the second element. Between the first element and a portion of the membrane, an element is interposed for varying, along the predetermined direction, the relative position of the first element with respect to the portion of the membrane. The transducer also includes a spring fitted and preloaded between the casing and the membrane, and a further element for adjusting the preload of the spring.

Abstract: The invention relates to a pressure sensor capable of measuring pressure accurately, and more particularly, to a pressure sensor comprising a box-shaped magnet, optionally having an inclined upper surface with a right side portion protruding higher than a left side portion, wherein the magnet is configured to radiate linear magnetic flux density in response to a change in distance along a straight line spaced uniformly apart from an N or S pole surface, whereby the pressure sensor can accurately detect a displacement in distance (position) and thus a pressure difference based on the displacement. The pressure sensor further includes a pipe connecting negative and positive pressures, a diaphragm movable in response to a difference between negative and positive pressures, a diaphragm support attached to a side of the diaphragm, a magnet attached to the diaphragm support to radiate linear magnetic flux density, a spring supporting the magnet, and the diaphragm and upper and lower cases housing these components.

Abstract: In order to reduce hysteresis and other noise components included in the output signal characteristic of a differential pressure sensor, an elastic reaction member which operates together with a diaphragm provided in a chamber of the differential pressure sensor includes a contact portion which contacts the diaphragm, and a plurality of springs which are arranged symmetrically about the contact portion. Each of the springs is a plate shaped or linear shaped spring which is bent into the form of a letter C, U, J, or V, and has one of its ends fixed to a wall which defines the chamber, while its other end is connected to the contact portion. When the contact portion shifts together with the diaphragm, the deformations of the plurality of springs are mutually balanced, so that rotation and horizontal deviation of the contact portion with respect to the diaphragm is suppressed.

Abstract: The invention relates to a pressure sensor capable of measuring pressure accurately, and more particularly, to a pressure sensor comprising a box-shaped magnet, optionally having an inclined upper surface with a right side portion protruding higher than a left side portion, wherein the magnet is configured to radiate linear magnetic flux density in response to a change in distance along a straight line spaced uniformly apart from an N or S pole surface, whereby the pressure sensor can accurately detect a displacement in distance (position) and thus a pressure difference based on the displacement. The pressure sensor further includes a pipe connecting negative and positive pressures, a diaphragm movable in response to a difference between negative and positive pressures, a diaphragm support attached to a side of the diaphragm, a magnet attached to the diaphragm support to radiate linear magnetic flux density, a spring supporting the magnet, and the diaphragm and upper and lower cases housing these components.

Abstract: A pressure sensor (S) includes an antenna member (10) that is adapted to be resonantly responsive to a desired frequency of electromagnetic radiation (12). An inductance changing body formed from a compressible dielectric material (14) is positioned in proximity to the antenna member (10). A housing member (16) houses the antenna member (10) in a desired proximity to the compressible dielectric material (14). The compression of the dielectric material (14) changes the effective dielectric constant of the antenna (10).

Abstract: A pressure sensor (S) includes an antenna member (10) that is adapted to be resonantly responsive to a desired frequency of electromagnetic radiation (12). An inductance changing body formed from a compressible dielectric material (14) is positioned in proximity to the antenna member (10). A housing member (16) houses the antenna member (10) in a desired proximity to the compressible dielectric material (14). The compression of the dielectric material (14) changes the effective dielectric constant of the antenna (10).

Abstract: An analogue position transducer, usable for example as a pressure switch in a household appliance, including a rigid casing accommodating a deformable membrane sensitive to hydraulic pressure, a first element engaged to the membrane so as to be mobile along with at least one portion of membrane in a predetermined direction (A) and a second element fixed to the casing and operatively coupled with the first element to provide a signal variable according to the relative position of the first element with respect to the second; in which between said first element and a portion of membrane there are interposed means for varying, along said predetermined direction, the relative position of said first element with respect to the portion of the membrane; the transducer also includes a contrast spring for the membrane fitted and preloaded between the casing and the membrane itself and means for adjusting the preload of the contrast spring.

Abstract: A system for measuring and converting to an observer intelligible form an internal physiological parameter of a medical patient. The invention allows transcutaneous telemetry of the measured information intracranial pressure via a system which includes a patient implanted sensor module and a processing and display module which is external of the patient and optically coupled to the sensor module via an external coupling module. A sensor within the implanted module transduces the measured information and a near infrared (NIR) emitter transmits this telemetry information when interrogated by the complementary external coupling module. Power for the sensor module is derived inductively through rectification of a transcutaneously-applied high-frequency alternating electromagnetic field which is generated by a power source within the external coupling module, in concept much like a conventional electrical transformer.

Abstract: In oil-filled pressure sensors, the measured pressure is applied to a compliant isolation diaphragm, which causes the pressure of the internal oil to increase until it equals the external pressure. The pressure is sensed by a pressure sensing capsule, such as a MEMS piezoresistive pressure sensor. The invention incorporates an electromagnetic force generator, such as a coil and a magnetic core, within the pressure sensor in order to generate simulated pressure. When the coil is energized, the electromagnetic field creates a uniform distributed force, which moves the isolation diaphragm directly, or via an external flexure, in a manner to cause the pressure of the internal oil to increase, which is sensed by the pressure sensing capsule, which responds by producing an output signal proportional to the electromagnetic force. The simulated pressure is employed in order to perform sensor operation monitoring and self-calibration via measurement of the output signal.

Abstract: A sensor assembly is provided. The sensor assembly includes a sensor configured to measure an impedance value representative of a sensed parameter and a transformer coupled to the sensor. The transformer includes at least one ceramic substrate and at least one electrically conductive line disposed on the ceramic substrate to form at least one winding. The electrically conductive line includes an electrically conductive material.

Abstract: The present inventors devised, among other things, exemplary differential pressure sensors suitable for use in a wide-variety filter-monitoring applications. One exemplary sensor, which operates in any physical orientation and consist of snap-together components that require no post-assembly adjustment, includes a diaphragm assembly, a magnet, and a magnetic sensor. The diaphragm moves in response to differential pressures exceeding a predetermined threshold difference, and the magnet which is physically coupled to the diaphragm assembly moves relative to a magnetic sensor. The magnetic sensor senses movement of the magnet and produces a signal that can be correlated by a computer or other circuitry to determine whether a filter is overly clogged and thus requires replacement.

Abstract: A magneto-elastic torque sensor and system include a substrate and a magneto-elastic sensing component formed from or on the substrate. The magneto-elastic sensing component and the substrate together form a magneto-elastic torque sensor, which when subject to a stress associated with a torque, shifts a characteristic frequency thereof linearly in response to the torque, thereby inducing a pathway by which magneto-elastic energy is coupled to excite vibrations in a basal plane of the magneto-elastic sensor, thereby generating torque-based information based on a resonant frequency thereof.

Abstract: The invention disclosed herein is a pressure transducer utilizing a Hall effect sensor to detect the displacement of the transducer's diaphragm. The pressure transducer includes a power supply to draw current from a 4 mA to 20 mA current loop and deliver current to the Hall effect sensor at an average rate of 4 mA or less.

Abstract: Ferromagnetic semiconductor-based sensor devices, including sensors for detecting pressure changes and sensors for detecting magnetic fields, such as switching events in a magnetic recording medium. The pressure sensors of the present invention detect pressure changes using magnetoresistive measurement techniques, and in particular GPHE techniques. Magnetic field detection sensors such as magnetic switching detection sensors include ferromagnetic semiconductor-based materials that provide enhanced sensitivity relative to known materials and techniques. Such magnetic switching detection sensors according to the present invention are particularly useful as a read head sensor for HDD and other magnetic storage technologies.

Abstract: A semiconductor pressure sensor is not influenced by a charged object in a fluid to be measured or an electric field from the outside, so satisfactory sensitivity and accuracy can be ensured. The semiconductor pressure sensor is provided with a diaphragm 4 that responds to the pressure of the fluid to be measured. The diaphragm includes a silicon substrate with piezoresistive elements, which together constitute a bridge circuit, being embedded therein, and a shield film for electromagnetic shielding formed on a surface of the silicon substrate at a side thereof at which the fluid to be measured is in contact with the silicon substrate. The shield film is electrically connected to the silicon substrate so as to have the same potential as that of the silicon substrate.

Abstract: A pressure sensor 10 includes a casing 12 configured to be able to be filled with a fluid 16 such as a liquid or a gas, in which at least part of a surface contacting this fluid 16 is formed of a giant magnetostrictive member 18 made of a giant magnetostrictive element, and detecting means for detecting a change in magnetic permeability or an amount of remanent magnetization attributable to expansion and contraction of the giant magnetostrictive member 18 based on a pressure change of the fluid 16 filled in this casing 12. The pressure sensor 10 can detect pressure at high sensitivity and high accuracy in a short time while achieving miniaturization of a device at the same time.

Abstract: If a pressure sensor is increased in size and therefore the inside diameter of a yoke is increased, a stopper is provided with a large-diameter portion. The large-diameter portion makes it possible to reduce the air gap between the stopper and the yoke and therefore suppress an increase in magnetic resistance. Besides, a magnetic circuit member is provided at an outer peripheral side of a sleeve. The magnetic circuit member makes it possible to reduce the air gap between the yoke and an armature and therefore suppress an increase in magnetic resistance.

Abstract: A magnetostrictive fluid-pressure sensor includes annular inner and outer cylinders, a first connector, annular second and third connectors, and first and second coils. The inner cylinder surrounds a fluid-receiving bore. At least one of the cylinders is a magnetostrictive cylinder. The first connector connects the first ends of the cylinders and has a first portion extending radially inward of the inner cylinder. The second connector connects the second ends of the cylinders and defines a fluid inlet. The third connector connects the cylinders and is positioned longitudinally between the first and second connectors. The first coil is positioned radially between the inner and outer cylinders and longitudinally between the first and third connectors. The second coil is positioned radially between the inner and outer cylinders and longitudinally between the second and third connectors.

Abstract: The invention involves a pressure fault device for indicating a threshold pressure or a threshold differential pressure. The present invention provides a cost effective way to determine where a pressure problem has occurred. The device includes a housing having at least one inlet aperture and an indicator aperture and having first and second bores in fluid communication respectively with one inlet aperture and the indicator aperture. The device further includes a magnetic piston which is biased in the first bore toward one inlet aperture and moveable a predetermined distance in another direction in the first bore in response to inlet threshold pressure. The device further includes a magnetic responder which is moveable toward the indicator aperture in the second bore in response to movement of the magnetic piston. The device further includes a latching plate in magnetic relationship to the magnetic responder when the piston moves the predetermined distance.

Abstract: Ferromagnetic semiconductor-based sensor devices, including sensors for detecting pressure changes and sensors for detecting magnetic fields, such as switching events in a magnetic recording medium. The pressure sensors of the present invention detect pressure changes using magnetoresistive measurement techniques, and in particular GPHE techniques. Magnetic field detection sensors such as magnetic switching detection sensors include ferromagnetic semiconductor-based materials that provide enhanced sensitivity relative to known materials and techniques. Such magnetic switching detection sensors according to the present invention are particularly useful as a read head sensor for HDD and other magnetic storage technologies.

Abstract: A device and procedure for checking the health of a pressure transducer in situ is provided. The procedure includes measuring a fixed change in pressure above ambient pressure and a fixed change in pressure below ambient pressure. This is done by first sealing an enclosed volume around the transducer with a valve. A piston inside the sealed volume is then driven forward, compressing the enclosed gas, thereby increasing the pressure. A fixed pressure below ambient pressure is obtained by opening the valve, driving the piston forward, sealing the valve, and then retracting the piston. The output of the pressure transducer is recorded for both the overpressuring and the underpressuring. By comparing this data with data taken during a preoperative calibration, the health of the transducer is determined from the linearity, the hysteresis, and the repeatability of its output. The further addition of a thermometer allows constant offset error in the transducer output to be determined.

Abstract: A pressure sensor for a motor vehicle includes a sensor housing and a base. A pressure bore through the base leads to a pressure space delimited on one side by the base and on the opposite side by a diaphragm connected sealingly to the base. An actuating element is carried on a side of the diaphragm facing away from the pressure space. The actuating element actuates a sensor element in the sensor housing via a non-contact actuation. For protection against leakage due to a break in the diaphragm, a sealing cap surrounds the diaphragm and the actuating element and is sealingly connected to the base.