Abstract: A pressure sensor particularly for measuring pressure within a diesel fuel pump comprises a screw-threaded bolt having a head and a shank and having a bore extending through the bolt through the head and shank. A transducer comprising a piezoelement is disposed in the bore, an electrical terminal extends from the bore through the head of the bolt, an electrical insulator is disposed between the transducer and bore, a threaded element positions one side of the transducer in the bore against the terminal, a spring in the bore extends from the shank end of the bore to bear against the opposite side of the transducer, and an incompressible material surrounds the spring in the bore to transmit a pressure force from a fluid pressure zone in the pump through the shank end of the bore to the transducer to provide a signal from the transducer representative of the pressure in the zone.

Abstract: In a pressure transmitter, a central region of an isolator diaphragm with a substantially flat shape at an undeflected position near room temperature has a depressed shape at a deflected position at a colder temperature. The isolator diaphragm is over a shaped concavity in a transmitter body with a concave shape which corresponds to the depressed diaphragm shape to reduce output error.

Abstract: A pressure transmitter has a pressure transducer in a transmitter housing. The transmitter housing includes a groove or a notch defining a flexure closely proximate a housing outer rim. The outer rim receives a large clamping force from a flange and is deflectable about the flexure for reducing transmission of axial and radial components of the clamping force from the housing outer rim to the transducer, which forces can cause distortions to the pressure transducer. Unevenly distributed clamping forces caused by differential thermal expansion of the flange, bolts and housing, are isolated from the transducer thereby reducing measurement errors. Further, transmission of hysteretic radial forces from the transmitter housing to the transducer caused by friction when the flange slides across the pressure transmitter housing, each having different thermal coefficients of expansion, is also reduced.

Abstract: A miniaturized transducer for in vivo measurements of physiological pressure has a transducer unit and an inner tube with a wall opening. A diaphragm covers the wall opening. Distinguishing for the invention is that the diaphragm is protected by an outer tube arranged outside the inner tube, and having a wall opening situated radially opposite the wall opening of the inner tube. An end closure closes off the distal end of the tube and a seal seals the outer tube against the inner tube. The lumen of the inner tube is in communication with the atmospheric pressure.

Abstract: A pressure sensor comprising a first housing piece defining a lumen therethrough and an opening to said lumen to provide communication between said lumen and a sensing element, said first housing piece having a first surface surrounding said opening, a second housing piece shaped for mating with said first housing piece and providing, with said first housing piece, a region for containing a sensing element in position to communicate with said lumen via said opening, said second housing piece having a second surface that surrounds said region and faces and conforms to the shape of said first surface, said second housing piece including an end of an electrical wire and wire contacts that are electrically connected to said wire, have portions at or near said second surface, and are spaced from each other, a sensing element in said region in communication with said flow path via said opening, said sensing element including sensor contacts aligned with respective wire contacts, and an elastomeric sheet providing a

Abstract: An absolute pressure sensor capsule and sensor resulting therefrom are disclosed. In one preferred embodiment, the capsule includes a sensor die of a first material, an intermediate spacer of a second material joined to the die and a base plate of a third material, the base plate having a variable thickness for changing the span shift, null shift, and static pressure of the die while compensating for changes in the calibration of the electrical die components.

Abstract: A pressure sensor of the present invention can perform pressure measurements under very severe mechanical and thermal conditions. It comprises a cell carrying a strain-measuring circuit. The cell is placed inside a body and is put into contact with the pressure to be measured. The cell has a hermetically sealed internal chamber inside which pressure is set to a predetermined reference value. The outside surface of the cell is subjected to the pressure to be measured. The cell is constituted by two half-shells joined together according to a join plane. The cell is preferably made of sapphire, with the crystal axis of the sapphire being perpendicular to the join plane so as to obtain isotropic stresses. A strain-gauge circuit is deposited on a plane surface of one of the half-shells, parallel to the join plane. The sensor is particularly suitable for testing oil deposits.

Abstract: A transmitter measures pressures and has a pressure sensor and an additional pressure sensor providing additional measurement capability to the transmitter, such as an extended measurement range or measurement redundancy. Both pressure sensors share an overpressure protection device which protects them from pressures exceeding a preselected pressure limit. The pressure sensors are batch fabricated and are formed in a single piece of brittle material.

Abstract: This pressure sensor comprises a housing having a cavity at at least one end portion thereof, a pressure detecting element provided with the cavity and generating an electric signal corresponding to the pressure detected, a transmitter for transmitting the signal to the outside of the housing, and hermetically sealed with one end thereof connected to the pressure detecting element, a sealed medium provided within the cavity to prevent deterioration of the pressure detecting element, a diaphragm provided to cover the surface of the cavity, and a sealing element for sealing the sealed medium within the cavity and provided in a portion connected to the cavity of the housing, and further, a sealing ability of either the hermetic seal portion of the transmitter or of the sealing element is improved by utilizing a back pressure of a pressure medium.

Abstract: In a differential pressure transmitter having pressure receiving diaphragms forming recesses, a center diaphragm therebetween so as to define two chambers filled with pressure transmission medium, first communication passages respectively connecting the two chambers to the recesses and second communication passages respectively connecting the two chambers to pressure measuring chambers. The diameters of the first communication passages are less than predetermined values determined by the viscosity and volume modulus of the pressure passages, and the volume of the pressure-measuring chamber. The frequency of characteristic vibration and gain of the pressure-measuring chamber and the second communication passage in one side is respectively and substantially equal to that in the other side. A drastic transient pressure transmitted to sensors in the pressure-receiving recesses is absorbed by the communication passages and is not transmitted to the sensor in the form of a differential pressure.

Abstract: An adapter for coupling a pressure transmitter to a vessel or tank carrying a liquid therein that establishes a hydrostatic pressure at a flanged opening has a planar surface that includes two spaced apart pressure ports that are aligned with and will mate with the isolator input ports of a differential pressure transmitter. The pressure ports are arranged so that the transmitter can be mounted very close to a side wall of the vessel or tank, with the hydrostatic pressure sensing port positioned closest to the vessel to eliminate errors caused by tilting of the adapter and transmitter from bulges that may occur in the vessel or tank side wall. Additionally, the adapter planar surface mounts the transmitter facing sideways, where the transmitter can be quite easily serviced, replaced, or examined.

Abstract: A solid state measurand sensor is described in which the pressure sensor element is protected from the measurand by a combination of a pressure transfer medium and a thin covering membrane. A method is described for forming the diaphragm in situ. The diaphragm material is selected from a group of materials which includes fluorosilicone, so as to substantially avoid entrapment of air or formation of voids in the pressure transfer medium such as would degrade the performance of the sensor. The pressure transfer medium is gel-like material such as dimethyl silicone and equivalents. Alternatively, the gel may be fluorosilicone and the diaphragm may be dimethyl silicone. The membrane material is chosen to be substantially impermeable to the ambients or process media being measured and also flexible, is to be poured and cured in place on the assembly during fabrication.

Abstract: The flow of a gas containing entrained particulate matter may be accurately, reliably and continuously measured, utilizing an apparatus comprising a self-cleaning orifice, including counter-rotating continuously scraped cylinders, and thermophoretic pressure taps.

Abstract: A shock mounted recorder carrier for a drill stem testing string, adapted for placement in a borehole, includes offset inner and outer bodies for placement of recorders within the carrier and further includes an overpressure gauge protector for protecting a set of recording gauges disposed in the carrier from a well fluid pressure which is greater than a predetermined amount above annulus fluid pressure and a balance joint for providing an oppositely directed force on the recording gauges relative to a direction of flow of the well fluid within the carrier thereby preventing the well fluid pressure from "bottoming out" the shock mount on which the recording gauges are mounted.

Abstract: A transmitter that provides an output indicating pressure difference between a line pressure and atmosphere outside the transmitter is made intrinsically safe by coupling the sensor cavity as well as other cavities where ignition can occur to atmosphere only through flame quenching paths. The opening in the transmitter housing in which the sensor is mounted has a plug including a sensor cavity that holds the sensor, and a fitting which is couplable to the pressure line. An isolator is used for transmitting the process pressure to the sensor through an isolator diaphragm acting on an incompressible filling the sensor cavity and transmitting pressure through a hole that is shaped to provide a flame quenching path. The passageway flame isolates the sensor from the process fluid line. The opposite side of the sensor is connected to atmosphere only through paths which are flame quenching because of the passageway shape.

Abstract: An apparatus for the accurate measurement of pressure changes has a reference accumulator and a differential pressure transducer. The reference accumulator stores a pressure representative of the environment being measured. The differential pressure transducer measures the difference between the reference pressure and the pressure of the environment being measured. Connected to the reference accumulator is a valve that allows the reference accumulator to be charged to a pressure representative of the environment being measured and provides protection to the differential pressure transducer from overpressuring. This valve can be controlled remotely by electrical means. With the use of an isolation means, such as an isolation bellows, the whole apparatus can be protected from the environment being measured.

Abstract: A transmitter measures pressures and has a pressure sensor and an additional pressure sensor providing additional measurement capability to the transmitter, such as an extended measurement range or measurement redundancy. Both pressure sensors share an overpressure protection device which protects them from pressures exceeding a preselected pressure limit. The pressure sensors are batch fabricated and are formed in a single piece of brittle material.

Abstract: A pressure sensor utilizes the effect of different elastic moduli between layers or sections of different material that are bonded together to form a body, so that when the bonded material unit is subjected to a uniform hydrostatic external pressure, the differences in the elastic moduli of each of the materials will cause the materials to deflect in a predictable manner proportional to pressure. The amount of warpage or deflection of the body of material can be measured as a function of pressure. Specifically, two layers of materials, such as silicon and borosilicate glass, which have substantially different elastic moduli can be bonded across an interface surface to form an assembly, and when subjected to a substantially uniform pressure on the exterior surfaces the assembly will deflect for indicating applied pressure at relatively high pressure ranges.

Abstract: A pressure sensing transmitter comprises a housing, a sensor base, a ceramic sensor, thick film resistor members, an isolation diaphragm, and an isolation fluid. A sensing surface contacting with the isolation fluid is formed with a spherical surface form, the thick film resistor members are sintered on a sintering surface of an opposite side against the sensing surface projection area, and a test fluid flow is isolated from the sensing mechanism by a metal diaphragm so that a process fluid pressure is transferred indirectly to the sensing element. According to the invention, since each of the thick film resistor members 14A and 14B are sintered at both the interior and exterior of the sensing surface projection area 13C, a sintering area can be made larger than that of a conventional one, so that a larger output can be maintained without losing any characteristic of the thick film resistor member.

Abstract: A pressure measurement system comprising a capacitance device whose outer interrelated capacitance plates are maintained in a relatively fixed position relative to one another while an intermediate capacitance plate responds to temperature. The plates are in a restricted enclosure containing a gas dielectric medium. The pressure of the gas dielectric medium (and consequently the density of the gas) is controlled as a function of a pressure to be measured. By measurement of capacitance relationships as a function of the temperature and density of the gas dielectric medium, a pressure measurement is obtained. The system is constructed with like types of materials where the capacitance device is in an enclosure chamber which is immersed in a pressure media. The capacitance device is constructed with a symmetrical arrangement to balance out effects of gravity or vibration. Construction of micro components utilizes an electrostatic bonding system which eliminated arcing during bonding.

Abstract: The invention relates to a pressure sensor having a ceramic diaphragm which is exposed at one of opposite surfaces thereof to a measurement fluid in an external space and deformable in response to a pressure of the measurement fluid, and a strain detector for producing an electrical output representative of an amount of deformation of the ceramic diaphragm. The ceramic diaphragm is fixedly supported at an outer portion thereof, so that a central working portion of the diaphragm is deformable in response to the pressure of the measurement fluid applied thereto. The sensor includes a baffling structure disposed adjacent the above-indicated one surface of the ceramic diaphragm. The baffling structure has portions which partially define a chamber to which the above-indicated one surface of the ceramic diaphragm is exposed.

Abstract: A reusable pressure transducer for use with a detachable dome. The pressure transducer includes a body having a recess with an opening covered by a flexible diaphragm. The body has a hole opposite the flexible diaphragm and a sensor placed over the hole. A dielectric gel fills the recess to transmit to the sensor variations in pressure imparted to the diaphragm.

Abstract: A sensor assembly and a protection device for use in conjunction with an air pressure tank. The sensor assembly consists of sensors that each act to give a visual indication when the pressure within the air pressure tank exceeds a preselected actuating pressure for the individual sensor. By observing the status of the sensors, an operator can quickly arrive at an approximation of the pressure within the air pressure tank. The sensor protection comprises a vapor separation unit that is disposed on the line that connects the air pressure tank to the sensor assembly. This protection unit acts to remove any vapor or fluids from the compressed air before it will reach the sensor unit. Due to the nature of the sensor units utilized, if the vapor or fluid were to reach the sensor units, it could clog them and prevent their operation.

Abstract: A pressure/differential pressure measuring device having a range plate with static and differential pressure sensors mounted therein. A high pressure isolation plate is mounted on one side of the range plate with a high pressure diaphragm mounted on the side of the high pressure isolation plate away from the range plate and sealed thereto forming a first fluid chamber between the inside of the high pressure diaphragm and the high pressure isolation plate side of the sensor assemblies. A low pressure isolation plate is mounted on the other side of the range plate with a low pressure diaphragm mounted on the side of the low pressure isolation plate away from the range plate and sealed thereto forming a second fluid chamber between the inside of said low pressure diaphragm and the low pressure isolation plate side of the sensor assemblies.

Abstract: The invention relates to a device for measuring pressures in a hydraulic or pneumatic system comprising preferably a piezoresistive pressure measuring cell disposed within the pressure housing in a pressure chamber filled with a separating fluid and separated from the medium to be measured by means of a diaphragm. In the pressure housing on the pressure input side before the pressure measuring cell or the sensor element (10.0), at least one pressure attenuation element (3.0;4.0;5.0) transferring the pressure is arranged before and/or behind the separating diaphragm (2.0). In an embodiment, a pressure attenuation element (3.0 or 5.0, resp.) is arranged on the pressure input side behind the diaphragm being provided with an elastic protective layer (2.1) turned toward the pressure attenuation element. The pressure attenuation element (3.0;4.0;5.0) consists of a microporous sintered metal, e.g.

Abstract: An improved seal for electronic components is disclosed, having a hydrophobic, microporous membrane sealed about a housing aperture to provide substantial internal to external pressure equalization during temperature and pressure variations encountered during the solder and cleaning process, while substantially sealing the housing aperture from damaging amounts of external contaminating fluids.The microporous membrane may be secured to a non-porous tape about a tape aperture, and the tape may be secured to the electronic component housing about the housing aperture; or the microporous membrane may be secured directly to the housing about the housing aperture.The hydrophobic, microporous membrane may be permanently sealed to the electronic component housing about the housing aperture; or the microporous membrane may be removed after the solder and cleaning process is completed. A tab portion may be secured to the microporous membrane for ease of removal.

Abstract: A transducer for sensing fluid pressure including an enclosure forming housing, a cup-shaped rubber-like mount having an end wall and an annular side wall for supporting a pressure sensing electronic chip against the inner end wall surface of the mount. The chip is supported against the end wall in covering relation to a small opening in the end wall which connects one side of the chip with atmospheric pressure. A layer of non-hardening sealant gel extending between the inner side wall surface completely covers the chip and transmits fluid pressure to a second surface of the chip but inhibits fluid contact and leakage past the chip.

Abstract: A pressure transducer for in particular the measurement of relatively high pressures in the range of 10,000-50,000 psi and including an elongated frame having a capillary tube extending therethrough and employing a coupler at one end of the frame for sensing input pressure. A sensing member is provided disposed about the capillary tube at the other end of the frame and has, defined with the capillary tube, a sensing chamber in communication with the capillary tube. A recess is provided in the sensing member defining a relatively thin wall adjacent the annular sensing chamber. This wall has a pressure responsive sensing surface that extends substantially parallel to the capillary tube length and upon which strain gages are secured. A method is described for securing the capillary tube with the sensing member in a liquid tight manner.

Abstract: The invention involves the design of a miniaturized piezoelectric pressure ransducer used for measuring pressure-time characteristics in gun tubes during the propellant ignition and burning process. The transducer utilizes a Z-cut tourmaline crystal as the piezoelectric pressure sensing element which produces a finite amount of electrical charge (normally expressed in picocoulombs) for a given change in pressure. The tourmaline crystal is incapsulated in a mechanical fixture which provides means for mounting in the gun tube. Electrical terminals are provided for connnecting to signal conditioning and recording instrumentation. Insulators are provided for electrically insulating the pressure sensing element from weapon ground.

Abstract: In a differential pressure transmitter, the respective measurement pressures are applied to a pair of barrier diaphragms respectively disposed on both side surfaces of a body, and movement of a sealed liquid caused by a differential pressure thereof is extracted as an electrical output by a differential pressure measuring pressure sensor provided by partitioning a sealing circuit. A sensor housing is manufactured independently of the body. The differential pressure measuring pressure sensor and a static pressure measuring pressure sensor for measuring a static pressure when applied with a measurement pressure applied to one of the pair of barrier diaphragms and a reference pressure such as an atmospheric pressure, are disposed in the housing. The housing is fixed to a housing mount portion of the body.

Abstract: A pressure transmitter assembly includes a laminated ceramic structure for providing fluid passages as well as a support for a pressure sensor, electronic circuitry, fluid barrier diaphragms and input process fluid connections. The laminated structure is comprised of a plurality of co-fired ceramic layers having the fluid passages molded therein to enable fill fluids within the assembly to apply input pressures as a differential pressure across the pressure sensor. In one embodiment of the invention, three ceramic layers are used while a second embodiment uses four layers with an overload diaphragm captured between two of the layers. The laminated ceramic structure can be extended in either embodiment to include an outer ceramic circuit board which is bonded with a fluid-tight interface with an adjacent one of the other ceramic layers.

Abstract: A pipe pressure sensor (10) comprises a chamber holder (14) for defining a hollow chamber (28) which is urged toward a pipe (20) to clamp a diaphragm (16) between the pipe and a portion of the chamber holder surrounding a pressure-inlet opening (30) into the chamber. The diaphragm has a round, sensing, protrusion (42) with a sensing tip (46) on an outer end thereof for extending outwardly from one side of the diaphragm to extend through a round hole (44) in the pipe so as to communicate pressure in the pipe to the chamber.

Abstract: A transmitter provides an output that is indicative of pressure and has two modular transmitter bodies, one including a sensor, and the other having an isolator diaphragm with a substantially non-compressible fluid that transfers movement of the isolator diaphragm to the sensor. The bodies each have mating passageways to transfer non-compressible fluid from one body to the other and are assembled together using a ring of extrusile material disposed around the mating portions of the passageways to seal the passageways together when the transmitter bodies are assembled. The isolation fluid is filled in the passageway of the bodies before the first and second transmitter bodies are assembled. The assembly can be accomplished without complex procedures and still insure that accurate transmitter operation will be obtained.

Abstract: A pressure transducer for the measurement of mid-range pressures in the preferred range of 500-7500 psi and including an elongated frame having a capillary tube extending therethrough and employing a coupler at one end of the frame for sensing input pressure. A sensing member is provided at the other end of the capillary tube and has a sensing chamber adapted to have at least one filler means disposed therein. A recess is provided in the sensing member defining a relatively thin wall adjacent the sensing chamber. This wall has a pressure responsive sensing surface that extends substantially parallel to the capillary tube length and upon which strain gages are secured.

Abstract: An improved diaphragm probe comprising a plate having a portion removed to form one or more cavities. At least two diaphragm strips sealed to close off each of the external openings of each of said one or more cavities. An incompressible fluid filling each cavity. A pressure sensitive instrument and means to transmit pressure changes at the diaphragms to said instrument in order to maximize the active diaphragm area with relation to the entry dimensions of the probe into a conduit.

Abstract: A semiconductor pressure sensor and method for its manufacture. Preferably, the pressure sensor is used as an absolute pressure sensor. The pressure sensor includes a pressure sensor chip of semiconductor material, the pressure sensor chip including a piezoresistive diaphragm. The pressure sensor is arranged in a casing which has an aperture for transmitting the ambient pressure to the diaphragm of the pressure sensor chip. The pressure sensor chip is fastened on a conductive tape and the conductive tape is a component of the casing. The casing consists of a hard synthetic material and contains the pressure sensor chip. The casing is configured so that the method of manufacture and tooling for manufacture allow cost-efficient production. The casing also offers protection for the pressure sensor during testing, equipping and during application in a circuit.

Abstract: A pressure transducer for in particular the measurement of relatively high pressures in the range of 10,000-50,000 psi and including an elongated frame having a capillary tube extending therethrough and employing a coupler at one end of the frame for sensing input pressure. A sensing member is provided disposed about the capillary tube at the other end of the frame and has, defined with the capillary tube, a sensing chamber in communication with the capillary tube. A recess is provided in the sensing member defining a relatively thin wall adjacent the annular sensing chamber. This wall has a pressure responsive sensing surface that extends substantially parallel to the capillary tube length and upon which strain gages are secured. A method as described for securing the capillary tube with the sensing member in a liquid tight manner.

Abstract: An isolator apparatus for coupling pressure from a pressurized fluid carried in a conduit to a pressure sensor in a pressure transmitter having an isolation diaphragm, isolation fluid, and a pressure sealing ring for providing an annular seal around an active region of the isolation diaphragm. The isolator apparatus includes a rigid support for spacing the pressure sealing ring away from the active region which reduces pressure measurement errors related to temperature-induced isolation fluid expansion, such that the annular seal overhangs the isolation diaphragm's active region.

Abstract: A pressure gauge which may be operably coupled to a fluid pressure supply device and a balloon catheter. The pressure gauge includes a mechanism which impedes a contaminant, such as corrosion and acid flux, from entering the pressurized fluid being measured. In one embodiment, this mechanism may include a piston positioned in a piston chamber. The piston has at least one, and preferably two, O-rings nested therearound to provide a seal with the piston chamber's wall. The piston may include an inter-gasket pressure chamber positioned between two O-rings which is communicated to the top or bottom of the piston, resulting in pressure equilibrium. Several inter-gasket pressure chambers may be provided.

Abstract: A liquid filled differential pressure detector comprises two pressure sensors. Each sensor is constructed of one or more capsules, which are pairs of diaphragms sealed at their peripheries. The innermost diaphragms are interconnected by a tube which contains a rod assembly. The interior of the sensors and interconnection tube form a sealed volume filled with a incompressible liquid. The rod assembly contacts the outermost diaphragm of the sensors and is displaced by expansion and contraction of the capsules caused by a differential pressure change against the outer surface of the sensors. The motion of the rod assembly is transformed into an electrical signal to indicate the pressure measurement. The apparatus is symmetrical about the center point of the tube to reduce error caused by the fluid's thermal expansion by causing equal and opposite forces to cancel, thereby preventing motion of the rod assembly.

Abstract: A deflecting diaphragm differential pressure sensor is formed so all electrical elements and connections from external circuitry to the sensor are isolated from the pressure media. The deflecting, pressure sensing diaphragm is made of a semi-conductor material, having piezoresistors disposed on a surface thereof to form strain gages to sense deflection of the diaphragm. The strain gage resistors are media isolated by a layer that overlies the strain gage resistors. All forms of the invention provide environmental protection for the electrical connections for external circuitry, which are subject to corrosion from the pressure media.

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

Abstract: A pressure transmitter is coupled directly to an industry standard flange adapter union having a standard bolt hole spacing. Small diameter isolator diaphragms are positioned on the transmitter housing at locations so that the industry standard flange adapter union which couple fluid pressure sources to act on the isolator diaphragms without an intermediate large flange or manifold as is presently required and using the fasteners for the adapter union to complete the coupling. The smaller isolaters fit within the bolt hole spacing of the industry standard adapter union.

Abstract: A transducer, particularly for ballistic high pressure measurements, comprises an assembly body, with a shoulder sealing section and a sensor member, which can be received in a recess in the assembly body. The assembly body can be screwed into a component, e.g. a gun barrel, the measurement area on the sealing section being sealed. The assembly body has a tubular extension extending beyond the sealing section, which extension encompasses the sensor member on a cylindrical fitting face. The high sealing forces required for sealing the measurement area are kept remote from the sensor member. The measuring sensitivity of the transducer is therefore independent of the prevailing tightening torques. A cylindrical gap between the sensor member and assembly body provides additional insulation between the sealing forces and the prestress forces prevailing in the sensor member. The cylindrical gap is sealed against the pressure medium by a force fit or weld between the assembly body and the sensor member.

Abstract: A flange mounted pressure transmitter uses a filled assembly having pressure transmitting fill fluid in a sealed capillary extending between a barrier diaphragm exposed to a fluid being monitored and a pressure sensor located in a housing attached to one end of a protective extension tube containing the capillary and supporting the diaphragm at the other end thereof. A gasket ring and a transmitter mounting flange are located on the exterior surface of the protecting tube and are arranged to provide a means for attaching the extension tube to a housing containing the fluid being monitored. The gasket ring is arranged to be welded to the exterior surface of the extension tube at a selectable distance from the barrier diaphragm which is effective to produce a desired location of the extension tube and the diaphragm within the housing containing the fluid being monitored.

Abstract: A fluid pressure transmitter suitable for use in potentially explosive atmospheres of the type comprising a measuring transducer provided with inductive, capacitive or resistive sensor means, the transducer having at least one measuring chamber in which electrical or electronic transducing elements are located, the measuring chamber being defined on one side by a measuring diaphragm and carrying on the other side at least one flameproof joint capable to permit passage of a pressure fluid in a direction towards or away from the measuring diaphragm. In order to ensure, at the same time, the compliance with explosion safety regulations, a sufficient pressure fluid flow rate and a great simplicity in structure and in carrying out the contruction, the flameproof joint or joints consist of one or more peripheral grooves provided at the interface that is defined by a small cylinder when force-fitted in a corresponding recess.

Abstract: A solid state semiconductor pressure sensor is described in which the pressure sensor element is protected from the ambient whose pressure is being measured by a combination of a pressure transfer medium and a thin covering membrane. A method is described for applying the thin covering membrane so as to substantially avoid entrapment of air or formation of voids in the pressure transfer medium which would degrade the performance of the sensor. The pressure transfer medium is a gel-like material such as a silicone rubber. The membrane is chosen to be substantially impermeable to the ambients being measured and sufficiently flexible to avoid attenuation of the input pressure signal. The membrane is cast in place by applying a thin liquid coating or a heat deformable film over the pressure transfer medium and then converting it into a thin solid membrane stuck to the pressure transfer medium and the pressure sensor body.

Abstract: A capacitive pressure sensor that is fabricated by a batch process affords isolation for the sensing element and leads from the pressure media and provides stress isolation as well. The pressure sensor is made up of a sandwich construction including a silicon wafer which is etched from one side to make cavities in a plurality of desired locations to form deflecting diaphragms, one surface of which acts as a capacitor plate. A glass layer is metalized on both sides and has holes drilled in locations that align with the diaphragms formed on the silicon wafer. The glass layer is anodically bonded to the wafer to form capacitance gap of a few microns relative to the one surface of each diaphragm. The assembly of the metalized glass layer and the silicon wafer is in a preferred form sandwiched between two additional layers, and bonded together in a vacuum atmosphere. The four layer sandwich is then cut up into individual sensors.

Abstract: An arrangement for monitoring pressure pulses in gas/particulate material media flowing through pipelines and/or containers includes an annular metallic housing which surrounds a flow passage and has in its interior an annular chamber which extends around the flow passage and is separated therefrom by a barrier layer of a wear resistant and porous material. Connecting ports for connecting the annular chamber respectively to a pulse conduit leading to a pressure measuring device and to a source of a rinsing gas open into the annular chamber.

Abstract: A pressure transducer assembly is disclosed for directly monitoring pressure in a fluid which flows through the assembly. The assembly includes a housing defining a chamber therewithin and having an inlet port and an outlet port in fluid-flow communication with the chamber. An electrically insulated body element is sealed within the chamber dividing the chamber into a first chamber and a second chamber. The first chamber is in fluid-flow communication with the inlet and outlet ports. The second chamber is separated from the first chamber by a fluid-tight seal such that any fluid present in the first chamber cannot enter the second chamber. A pressure transducer sensor is secured in the insulated body and exposed to the first chamber such that the sensor can determine the pressure in a fluid in the first chamber and convert the pressure into electric impulses. The sensor is separated from the fluid in the first chamber by an insulating medium across which fluid pressure can be determined.