Abstract: A pressure transducer has an H-shaped cross-sectional header having a front and a back section. The front and back sections are of equal diameter and are circular. Each front and back section has a depression with an isolation diaphragm covering the depression. Each diaphragm is of equal size and the depressions communicate one with the other via a central channel in the central arm of the H. A pressure sensor communicates with the channel, where the pressure sensor responds to a first pressure applied to the first isolation diaphragm and a second pressure applied to the second isolation diaphragm. The pressure sensor produces an output equal to the difference in pressure. The differential pressure transducer having both diaphragms of the same size and still enabling leads from the sensor to be brought out.

Abstract: A pressure activated remote microphone is provided within a communication system (100). A face mask (102) incorporates a remote microphone (118) and one or more pressure sensor(s) (122). When a user puts on the mask (102), the remote microphone (118) is enabled in response to the pressure sensed by the pressure sensors (122). When the mask (102) is removed, the remote microphone (118) is disabled in response to the change in pressure sensed by the pressure sensor(s) (122).

Abstract: The present invention relates to a temperature-compensated pressure sensor assembly for fitting within the valve stem of a vehicle tire. The assembly includes a substrate assembly defining a plurality of holes. A pressure sensor is mounted to the substrate assembly. The pressure sensor includes a first deflectable membrane defining a first chamber and a first cap mounted to the membrane to form a second chamber. A temperature compensation sensor is mounted to the substrate assembly. The temperature compensation sensor includes a second deflectable membrane mounted to the substrate assembly to define a third chamber and a second cap mounted to the other membrane to form a fourth chamber.

Abstract: There is disclosed a header for a differential pressure transducer. The header has a cylindrical sensor housing section which has a front and a back surface. The front surface has a sensor accommodating recess. There is a plurality of terminal pins extending from the front surface and directed through the housing to extend from said back surface. The pins are arranged in a semi-circular pattern, said sensor housing having a stem aperture and cylindrical wall. A stem housing is positioned in the stem aperture and is brazed thereto. The stem housing has a stem passageway directed through the housing which communicates with a passageway in the cylindrical sensor housing. The cylindrical sensor recess contains a sensing device which receives a first input pressure on one diaphragm surface of the sensing device and a second input pressure on a second surface of the diaphragm to produce a differential output pressure. The header, as indicated, is rugged and simple to use and produce.

Abstract: A pressure difference measuring cell for registering pressure difference between a first pressure and a second pressure, comprises: an elastic measuring arrangement having at least one measuring membrane, or diaphragm, that comprises silicon; a platform, which is pressure-tightly connected with the elastic measuring arrangement; a first hydraulic path for transferring a first pressure onto a first surface section of the elastic measuring arrangement; and a second hydraulic path for transferring a second pressure onto a second surface section of the elastic measuring arrangement. The first pressure opposes the second pressure, and the elastic deflection of the measuring arrangement is a measure for the difference between the first and the second pressure, wherein the pressure difference measuring cell has additionally at least one hydraulic throttle, characterized in that the at least one hydraulic throttle comprises porous silicon.

Abstract: A differential pressure sensor for measuring a pressure difference between two high-pressure environments is comprised of a sensor block including internal, oil-filled channels leading to an internally positioned differential pressure sensor element. Two process diaphragms are provided for transferring pressure from the high-pressure environments for isolating two distinct internal oil channels from the high-pressure environments. In order to achieve small internal oil volumes in the sensor block, additionally two separating discs, which initially separate between the two internal oil channels, are positioned in fluid communication with the high-pressure environments in order to block for the pressure from the high-pressure environments against the oil channels “from behind.” The separating discs bear against abutment faces having small openings into the internal oil channels.

Abstract: A pressure transducer for a pressure sensor (2) for determining at least one pressure (pa, pb) in a process media (3a, 3b) has a housing (4) with a separating diaphragm (5a, 5b), at least one first pressure-sensing element (6a, 6b), a contact media (7a, 7b), at least one first connection element (8a, 8b) and at least one first seal (9a, 9b). The separating diaphragm (5a, 5b) separates the process media (3a, 3b) from the contact media (7a, 7b), the contact media (7a, 7b) conveys the pressure (pa, pb) of the process media (3a, 3b) determined by the separating diaphragm (5a, 5b) to the first pressure-sensing element (6a, 6b). The first seal (9a, 9b) houses the first connection element (8a, 8b) and the housing (4), the separating diaphragm (5a, 5b) and the first seal (9a, 9b) form a first pressure chamber (10a, 10b).

Abstract: A pressure sensor is provided with a carrier (2), which in an inner region includes a membrane (4) on which at least one first measurement element (R1?) for detecting a pressure impingement of the membrane (4) is arranged. Additionally, at least one second measurement element (R3?) for detecting a pressure impingement of the membrane (4) is arranged on the membrane. The first measurement element (R1?) and the second measurement element (R3?) are arranged distanced differently far from the edge of the membrane. The output signals of the first and the second measurement element (R1?, R3?) are evaluated together in a manner such that the two measurement elements (R1?, R3?) detect a differential pressure acting on the membrane (4), and thereby compensate the influence of the system pressure acting on both sides of the membrane (4).

Abstract: A dual pressure sensor using a reduced number of parts to simplify its structure and having increased ease of assembly and improved air tightness. The dual pressure sensor has an airtight container, two pressure sensor units received in the airtight container so as to be in intimate contact with each other and a substrate. The pressure sensor units has two bases, two pressure sensing diaphragm chips, and an output correction circuit. The pressure sensing diaphragm chips are secured to the bases, respectively. The bases are constructed respectively from base bodies having communication paths formed inside them and also respectively from pressure introduction sections integral with and projecting from the base bodies. The pressure introduction sections respectively project outward from insertion holes formed in the airtight container.

Abstract: A pressure transmitter is provided. The pressure transmitter includes a pressure sensor including a pair of process fluid pressure ports each having a deflectable diaphragm. A first variable capacitor is disposed within the pressure sensor and has a capacitance that varies with differential pressure between the process fluid ports. A second variable capacitor is disposed within the pressure sensor and has a capacitance that varies with line pressure.

Abstract: There is disclosed an apparatus for measuring multiple pressures within different pressure ranges. The apparatus contains multiple pressure sensors which are positioned on a housing, where each pressure sensor is adapted to measure pressure within a different pressure range. The housing has an input port which is constructed to communicate with different output ports, where the output ports communicate with each different pressure sensor utilized in a different pressure range. The input port has a stepped or keyed aperture which is adapted to receive different pressure adapters. The input port enables the selective insertion of various pressure adapter members as indicated where each pressure adapter member can only be inserted within the input port to a desired position, where at that position, the pressure applied to the input port will be directed to the proper pressure sensor.

Abstract: Methods and systems for measuring pressure through a jointless pressure sensor port are disclosed, including permitting a substance to pass into a jointless pressure sensor port comprising an aperture, a channel, and a diaphragm having a larger area than the area of the aperture, allowing the substance to come into contact with the diaphragm resulting in a mechanical stress on the diaphragm, and measuring the mechanical stress to generate a signal indicative of the substance pressure.

Abstract: A process pulsation diagnostic system comprises a primary element, a sensor and a processor. The primary element generates a differential pressure along a fluid flow. The sensor samples the differential pressure. The processor generates a pulsation diagnostic based on a standard deviation of the differential pressure, such that the pulsation diagnostic is indicative of a degree of process pulsation in the fluid flow.

Abstract: The invention relates to a vacuum measuring cell device comprising a vacuum membrane measuring cell (8) having a connecting means (5, 6) arranged thereon for a communicating connection to the medium to be measured, an electronic system (34), which is electrically connected to the vacuum membrane measuring cell (8), and also comprising a heating arrangement (20, 21) for heating the vacuum membrane measuring cell (8) to a predefinable temperature value, wherein the heating arrangement (20, 21) substantially encloses the entire vacuum membrane measuring cell (8) such that said cell forms a thermal container (20). Said container constitutes a thermal body (20a) in the area of the connecting means (5, 6) and connecting means (6) are guided through it, the connecting means thereby being thermally contacted at least in some areas by the thermal body. The thermal container (20a) comprises a heating source (21) for the heating thereof.

Abstract: A capacitance manometer comprises: a flexible diaphragm including a first electrode structure; an electrode structure including second and third spaced-apart electrode structures secured relative to the diaphragm so as to establish a capacitance between the first electrode structure and the second electrode structure and a capacitance between the first electrode structure and the third spaced-apart electrode structure, wherein the capacitances between the first electrode structure and each of the second and third electrode structures change with changes in differential pressure placed on opposite sides of the flexible diaphragm; and a thick film dielectric material disposed between the first electrode and each of the second and third spaced-apart electrode structures so as to increase the gain in capacitance of the manometer without decreasing the distance between the first electrode structure and each of the second and third electrode structures and without increasing the stroke of the flexible diaphragm, wh

Abstract: There is disclosed apparatus for measuring multiple pressures within different pressure ranges. The apparatus contains multiple pressure sensors which are positioned on a housing, where each pressure sensor is adapted to measure pressure within a different pressure range. The housing has an input port which is constructed to communicate with different output ports, where the output ports communicate with each different pressure sensor utilized in a different pressure range. The input port has a stepped or keyed aperture which is adapted to receive different pressure adapters to assure that, for example, only a high pressure will be applied to the high pressure sensor during high pressure measurements. By selecting another adapter, a mid-range pressure and a high pressure will be applied to the pressure sensors during the measurement of a mid-range pressure. By receiving a different adapter, a low pressure will be applied to all the pressure sensors during low pressure measurement.

Abstract: The invention relates to a method and apparatus for a gauge for indicating a pressure of a fluid, including a gauge having a face where the face has a first plurality of graduation marks, each for indicating a pressure in an ascending direction. The face also has a second plurality of graduation marks, each for indicating a pressure in a descending direction. In addition, the gauge includes a sensor magnet for detecting the pressure of the fluid, a pointer magnet coupled to a pointer and in communication with the sensor magnet for moving the pointer in correspondence with a movement of the sensor magnet, and wherein the pointer traverses across both the first and second pluralities of graduation marks for indicating the pressure of the fluid in either an ascending direction or descending direction.

Abstract: A pressure transducer has an H-shaped header having a front and a back section. The front and back sections are of equal diameter and are circular. Each front and back section has a depression with a diaphragm covering the depression. Each diaphragm is of equal size and the depressions communicate one with the other via a central channel in the central arm of the H. A pressure sensor communicates with the channel, where the pressure sensor responds to a first pressure applied to the first diaphragm and a second pressure applied to the second diaphragm. The pressure sensor produces an output equal to the difference in pressure. The differential pressure inducer having both diaphragms of the same size and still enabling leads from the sensor to be brought out.

Abstract: A pressure sensor for sensing a fluid pressure comprising: a first chamber including a first conductive membrane, wherein a fluid is sealed within the first chamber at a reference pressure such that the first conductive membrane deflects from pressure differences between the reference and the fluid pressure; a second chamber including a second conductive membrane sealed from the fluid pressure, wherein the second membrane deflects in response to a change in temperature which the pressure sensor is exposed thereto; and a circuit in electrical communication with the first and second conductive membrane, the circuit being configured to obtain a first and second signal from the first and second conductive membranes respectively, the first and second signals being indicative of the deflection of the first and second conductive membranes, wherein the circuit adjusts the first signal by the second signal to generate an output signal indicative of the fluid pressure.

Abstract: An acoustic monitoring system that is able to verify the success or failure of the positional adjustment of a valve without the need for additional energy during non-invasive reprogramming is provided. The acoustic monitoring system includes a programmer for generating a sequence of commands to adjust the valve mechanism, and for receiving acoustic signals for analysis, a transmitter to implement the command and adjust the valve, and a sensor for detecting an acoustic signal generated from the valve during execution of the commands. A method for using the acoustic monitoring system is also provided.

Abstract: A micromechanical pressure sensor includes a first diaphragm and a second diaphragm accommodated in a shared semiconductor substrate. The two diaphragms facilitate independent pressure sensing of one or more media, by the fact that a respective pressure variable is sensed by way of the deflection of the respective diaphragm. A cap above the first diaphragm defines a hollow space that is connected to the hollow space below the second diaphragm.

Abstract: A semiconductor filter is provided to operate in conjunction with a differential pressure transducer. The filter receives a high and very low frequency static pressure attendant with a high frequency low dynamic pressure at one end, the filter operates to filter said high frequency dynamic pressure to provide only the static pressure at the other filter end. A differential transducer receives both dynamic and static pressure at one input port and receives said filtered static pressure at the other port where said transducer provides an output solely indicative of dynamic pressure. The filter in one embodiment has a series of etched channels directed from an input end to an output end. The channels are etched pores of extremely small diameter and operate to attenuate or filter the dynamic pressure.

Abstract: A differential pressure sensor includes a micro-electromechanical sensor die fabricated as a plurality of sensor die sites on a semiconductor wafer, and then singularized, the sensor die having a top face surface including die electrical output pads exposed to a first test fluid source and a bottom side surface exposed to a second test fluid source. The differential pressure further has a sensor die support member having a die support member fluid access port with a support member port perimeter; wherein one of the top face surface or the bottom side surface is sealed fully around the support member port perimeter by a wafer scale seal formed on the plurality of sensor die sites before die singulation. Wafer scale seals may be formed by a photofabrication process, screen printing, stamp printing, or pressure transfer printing. Some embodiments may include a photofabricated seal formed by a photosensitive polydimethylsiloxane material, by a filled photofabricated mold, and by photopatterned glass frit.

Abstract: A fluid assisted gas gauge coupled to a pressure sensor enables proximity measurements to be made with a high bandwidth. A two-chamber gas gauge, containing a gas-filled measurement chamber and a fluid-filled transfer chamber and a diaphragm separating the two chambers, exhausts gas onto the surface being measured, while the incompressible fluid transmits the pressure to a pressure sensor. By minimizing the gas volume of the gas gauge, the response time is enhanced. In addition, the incompressible fluid permits the pressure sensor to be remotely located from the point of measurement without sacrificing the response time performance. In an embodiment, a differential bridge version of the fluid assisted gas gauge reduces common mode effects.

Abstract: An absolute pressure transducer for outputting a signal indicative of an absolute pressure of a process to be measured is provided. The pressure transducer consists of a pressure-tight pressure port, which is connectable to the process, a housing accommodating pressure sensors and a common circuit board, a first pressure sensor, which analogically detects a difference between the process pressure and an ambient pressure inside the housing, a second pressure sensor, which detects the ambient pressure inside the housing as an absolute pressure, and the common circuit board, which is connected to both the first pressure sensor and the second pressure sensor and furthermore has a data processing unit. Here, the second pressure sensor is adapted to issue an electronic signal indicative of the ambient pressure.

Abstract: The disclosure relates to a differential pressure transducer unit comprising an over-load protection system which is used to measure low differential pressure in liquids and gases under high static pressure load which can be connected to flanges on the working pressure lines. The differential pressure transducer unit consists of a planar multi-layered arrangement comprising layers which are conductive, insulating and which are insulated from each other, whereby the insulating and conductive layers comprises recesses which at least partially cover each other, wherein the measuring mechanism and the measuring value processing means are accommodated. At least one of the layers is a functional component of the over-load protection system.

Abstract: The present invention provides an apparatus for pressure sensing. The apparatus comprises a series of Bragg gratings and a light guide incorporating the series of Bragg gratings. The apparatus also comprises a plurality of moveable wall portions having opposite first and second sides. Each moveable wall portion is positioned so that a change in pressure at one of the sides relative to a pressure at the other side will move the moveable wall portion that is coupled to respective Bragg gratings so that the movement of one of the moveable wall portion causes a force on the respective Bragg grating resulting in a change in strain of the respective Bragg grating. An internal space at each Bragg grating is in fluidal communication with an internal space at an adjacent Bragg grating whereby pressure differences between adjacent internal spaces are reduced.

Abstract: A compact absolute and gage pressure transducer consists of two sensors made from the same silicon wafer and adjacent each other on the wafer. The transducer contains a common header with a first and a second input port for receiving a first and a second pressure, respectively. The second port is directed through a reference tube into the hollow of a housing to apply pressure from the reference tube to the common sensor arrangement. The first port is directed from another surface of the housing to direct pressure to both sensor devices. One sensor operates as a gage sensor producing an output proportional to the difference between input pressures and the other sensor produces an absolute output. The sensor chip is associated with a sensor header which includes an alignment pin extending therefrom, and a guide plate with an aperture for accommodating an alignment pin.

Abstract: A pressure sensor module is disclosed. The pressure sensor module comprises a sensing element (1) mounted on a front side (3) of a support member (5). The support member (5) comprises a hole (7) through the support member (5) from the front side (3) to a back side (9). The sensing element (1) covers the hole (7) at the front side (3). A back side barrier (6) provided at the back side (9) of the support member (5) surrounds a surface of the back side (9) of the support member (5) and forms an enclosed area (8), wherein the enclosed area (8) and the hole (7) form a pressure channel (10). A back side protective member (2) fills the hole (7) and at least partially the enclosed area (8). The support member (5), back side barrier (6) and back side protective member (2) form a module that can be placed during production of the pressure sensor in a housing of the pressure sensor.

Abstract: A measuring device for detecting and indicating changes in fluid pressure of a test environment relative to ambient fluid conditions, wherein the measuring device includes a linear gear rack having an alignment spur, an indicator needle associated pinion gear, calibrated indicia for visual measure of a pressure change event, and a deflectable diaphragm element. The alignment spur acts upon the pinion gear by maintaining close relationship of the linear gear rack and the needle associated pinion gear and counteracts torque and off-center forces created by the linear rack gear upon deflection of the deflectable diaphragm, thus providing improved resolution of small pressure changes and increased accuracy of measurement as the measuring device operates through a cycling period.

Abstract: A pressure sensor includes a housing, a pressure input orifice opened on a pipe sleeve formed on the housing, a diaphragm that seals the pressure input orifice and has one face as a pressure receiving face, a force transmitting unit connected to a central area of the other face of the diaphragm in the housing, and a pressure sensitive element whose detection direction of a force is a detection axis. A displacement direction and the detection axis of the force transmitting unit are roughly orthogonal to the pressure receiving face. One end and the other end of the pressure sensitive element are respectively fixed to the housing and the force transmitting unit with an adhesive therebetween, and the adhesive is an inorganic adhesive.

Abstract: A multivariable process fluid pressure transmitter includes an electronics module and a sensor module. The sensor module is coupled to the electronics module. A process fluid temperature sensor is coupled to the process fluid pressure transmitter. A differential pressure sensor is disposed within the sensor module and is operably coupled to a plurality of process fluid pressure inlets. A static pressure sensor is also disposed within the sensor module and is operably coupled to at least one of the process fluid pressure inlets. A first temperature sensor is disposed within the sensor module and is configured to provide an indication of a temperature of the differential pressure sensor. A second temperature sensor is disposed within the sensor module and is configured to provide an indication of a temperature of the static pressure sensor. Measurement circuitry is operably coupled to the differential pressure sensor, the static pressure sensor, and the first and second temperature sensors.

Abstract: A differential pressure transmitter includes first and second process fluid inlets. A differential pressure sensor is disposed within the transmitter and has first and second sensor inlets. A first isolator diaphragm is located proximate the first process fluid inlet and is operably coupled to the first sensor inlet through a first fill fluid volume. A second isolator diaphragm is located proximate the second process fluid inlet and is operably coupled to the second sensor inlet through a second fill fluid volume. Measurement circuitry is operably coupled to the differential pressure sensor and configured to measure an electrical parameter of the sensor and provide an indication of the measured parameter. A third fluid volume substantially surrounds the differential pressure sensor. The third fluid volume exerts a compressive force on the differential pressure sensor.

Abstract: A differential pressure sensor includes two pressure ports for allowing media to pass into contact with both the top and bottom sides of the diaphragm. A silicon pressure sensor die can be attached between the pressure ports using die attach materials for sensing a differential pressure between the media to evaluate media differential pressure. A cap with an opening can be placed on topside of a diaphragm formed in the silicon pressure die. The silicon pressure die can include die bond pads that can be electrically connected to the diaphragm to output electrical signals. The cap can seal the die bond pads from the harsh media and route the electrical signals therein. Media can pass through the opening in the cap such that a media path to the top of the diaphragm is not exposed to the die bond pads of the silicon pressure die to ensure long-term sensor reliability.

Abstract: A pressure sensor assembly is provided for fitting within the valve stem of a vehicle tire. The assembly comprises a substrate assembly defining a plurality of holes. A pressure sensor and a temperature compensation sensor are mounted to the substrate assembly. Each sensor includes a deflectable membrane defining a first chamber and a cap mounted to the membrane to form a second chamber. A cover is provided for engaging with the pressure sensor and the temperature compensation sensor to define an active chamber and reference chamber respectively. The active chamber is exposed to tire pressure when the pressure sensor assembly is fitted within the valve stem whereas the reference chamber is sealed from tire pressure.

Abstract: The invention relates to a differential pressure sensor array comprising a differential pressure sensor which is inserted in a receiving space in the direction of the longitudinal axis thereof. At least one sealing element that separates the receiving space into a first and a second pressure zone when the differential pressure sensor is inserted is disposed on the differential pressure sensor and/or in the receiving space. The first pressure zone is embodied entirely in an area located between a peripheral surface of the differential pressure sensor surrounding the longitudinal axis and an interior wall of the receiving space which faces said peripheral surface. At least one section of the first pressure zone extends only across a subarea of the peripheral surface in the circumferential direction. Also disclosed is an associated differential pressure sensor.

Abstract: A pneumatic fire detector is disclosed having a switch module comprising a manifold operatively connected to a sensor tube, the switch module incorporating respective forming tubes for applying a sufficient pressure first to the outer surface of an installed diaphragm and thereafter to a pre-determined pressure through the manifold to deform the diaphragm outwards and into contact with a respective switch.

Abstract: The invention provides for a temperature compensating pressure sensing arrangement. The arrangement includes a substrate having sealed channels on which is deposited a CMOS layer, with a conductive layer and a passivation layer deposited on the CMOS layer. The arrangement also includes a conductive active membrane spaced from the conductive layer to form an active chamber, and a conductive reference membrane spaced from the conductive layer to form a sealed reference chamber. Further included is a cap which covers the membranes, said cap exposing the active membrane to an outside fluid pressure. The active membrane further defines a foot which is located between the substrate and cap with a leg extending away from the substrate and terminating in a substantially planar deflectable portion, which deflects due to differential pressure stresses so that an active capacitance is developed between the active membrane and the conductive layer depending on the electrical permittivity e of the fluid.

Abstract: A pressure sensor is provided with a carrier (2), which in an inner region includes a membrane (4) on which at least one first measurement element (R1?) for detecting a pressure impingement of the membrane (4) is arranged. Additionally, at least one second measurement element (R3?) for detecting a pressure impingement of the membrane (4) is arranged on the membrane. The first measurement element (R1?) and the second measurement element (R3?) are arranged distanced differently far from the edge of the membrane. The output signals of the first and the second measurement element (R1?, R3?) are evaluated together in a manner such that the two measurement elements (R1?, R3?) detect a differential pressure acting on the membrane (4), and thereby compensate the influence of the system pressure acting on both sides of the membrane (4).

Abstract: A differential liquid pressure sensor (10) has an upper housing (12) that mounts a connector portion (12a) and receives in a recess a sense element module (14). The sense element module is a body in which a generally U-shaped oil filled passageway (14h) is formed with openings at opposite ends provided on respective first and second diaphragm mounting surfaces. A fluid pressure sense element, such as a piezoresistive sense element (15) is disposed in one of the passageway openings and flexible metal diaphragms (14a, 14b) are mounted on the respective diaphragm mounting surfaces of the module facing a common direction. A lower housing (18) having first and second port connections for the respective diaphragms is disposed on the lower surface of the module.

Abstract: A digital signal representative of a difference in pressure is received from a differential pressure transmitter. A noise signal is obtained by processing the signal through a band pass filter or otherwise to provide a filtered noise signal. Absolute values of the filtered noise signal are calculated and compared to one or more predetermined threshold values to determine if one or more impulse lines are plugged. A training mode is used to determine the thresholds, which may be a function of flow rate and other flow conditions.

Abstract: A differential liquid pressure sensor (10) has an upper housing (12) that mounts a connector portion (12a) and receives in a recess a sense element module (14). The sense element module is a body in which a generally U-shaped oil filled passageway (14h) is formed with openings at opposite ends provided on respective first and second diaphragm mounting surfaces. A fluid pressure sense element, such as a piezoresistive sense element (15) is disposed in one of the passageway openings and flexible metal diaphragms (14a, 14b) are mounted on the respective diaphragm mounting surfaces of the module facing a common direction. A lower housing (18) having first and second port connections for the respective diaphragms is disposed on the lower surface of the module.

Abstract: A filter upstream-side pressure sensor detects the pressure on an upstream side of a filter. A filter downstream-side pressure calculating device subtracts an actual measurement value of the pressure difference between the upstream side and the downstream side of the filter from a pressure value on the upstream side of the filter. Based on this subtraction, the filter downstream-side pressure calculating device calculates a pressure value on the downstream side of the filter. A filter downstream-side pressure estimating device estimates a pressure value on the downstream side of the filter. An abnormality detection device compares the difference between the calculated pressure value and the estimated pressure value with a threshold. If the difference exceeds the threshold, it is determined that at least one of a differential pressure sensor and the filter upstream-side pressure sensor is not working normally.

Abstract: An enhanced pressure sensing system and method use an external diaphragm to address issues involved with accurate and prolonged measurement of fluid pressure, such as of blood flowing in a vascular structure. Some external diaphragms include a metallized layer or other highly impermeable layer to furnish a high degree of seal at least near to hermetic grade. As temperature of the intermediary fluid changes, the external diaphragm is able to move in a direction that minimizes differential pressure across the external diaphragm over an operational temperature range thereby reducing pressure change of the intermediary fluid due to change in temperature of the intermediary fluid. Relatively smooth hydrodynamic surfaces can be used as well as a bi-layer construction.

Abstract: A high-temperature pressure sensor element for power units includes a substrate, in which an interior space is developed, a deformable membrane, which separates the interior space from the exterior space in order to deform when the exterior pressure changes, and a strain measuring element, which is arranged on the membrane, for measuring the deformation of the membrane. The substrate, the membrane, and the strain measuring element are manufactured from the same high-temperature-stable material, such as an alloy. By way of example a nickel base alloy may be used. A component for a power unit, such as a turbine blade for an airplane or rocket engine, includes an integrated high-temperature pressure sensor element of this type.

Abstract: A ruggedized pressure sensor is described for high pressure applications having a top part of hard material with a surface adapted to deform when exposed to pressure, transducers to transform deformation of the surface into a signal proportional to the pressure, and a base part of hard material, wherein the base part has one or more openings.

Abstract: A combined fluid pressure transducer and temperature sensor (10) has a housing (12) containing a variable capacitor (14) having a rigid substrate (14a) and attached flexible diaphragm (14b) in sealed, spaced apart relation. The capacitor is mounted in the housing so that the outer face surface of the diaphragm is exposed to a fluid pressure chamber (12k). A temperature responsive sensor element (28) is disposed on the outer face surface of the diaphragm and covered by a thin protective layer. A fluid flow diffuser (30) is disposed in the fluid pressure port (12b) for directing fluid flow across the temperature sensor.

Abstract: The object of this invention is to provide a method of maintaining a multi-tubular reactor which can ensure the uniformity of states of reaction in the reaction tubes in the multi-tubular reactor. This invention is a method of maintaining a multi-tubular reactor in good condition by selecting a part of reaction tubes in a multi-tubular reactor at random, measuring a differential pressure occurring in each reaction tube when passing gas therethrough, separating any reaction tube showing an abnormal differential pressure as compared with the average of differential pressures in reaction tubes packed with an fresh catalyst of the same kind, giving adequate treatment to the separated reaction tube and returning it into the reactor with any other selected reaction tube falling within a normal range.

Abstract: A capacitative pressure sensor (30) for harsh environments such as vehicle tires. The sensor has two opposing electrodes (36 and 50). One electrode is a membrane (50) that extends between fluid at a reference pressure and fluid at the pressure to be sensed. In use, the flexible membrane (50) deflects due to pressure differentials between the reference pressure and the fluid pressure. Associated circuitry converts the deflection into a signal indicative of the pressure to be sensed. The membrane is a laminate at least partially formed from a transition metal nitride because transition metal nitrides are a metal ceramics with high yield strength and metallic bonding that makes it suitable for use in extreme environments. They can also readily include an oxidizing component such as aluminium so that the membrane form a passivating surface oxide layer to protect it from oxidative failure.

Abstract: A method and apparatus for designing a differential pressure sense die based on a unique silicon piezoresistive technology for sensing low differential pressure in harsh duty applications is disclosed. The pressure sense die comprises of an etched pressure diaphragm and a hole that is drilled through the sense die wherein the pressure sense die possess a backside and a front side and are associated with varying pressures. A top cap can be attached to the front side and an optional constraint for stress relief can be attached to the backside of the differential pressure sense die. The top cap and the constraint comprise of glass and/or silicon and can be attached with an anodic bonding process or glass frit process.