Abstract: A pressure sensor comprises a diaphragm mounted on a housing and subject to pressure. Stress sensitive resistors are connected to circuit traces on the diaphragm which in turn are wirebonded to a compensation IC. The IC is directly mounted on the diaphragm principally or wholly in an area which is not subject to flexing. A connector has a dome partially covering the diaphragm and holds terminal blades having ends extending away from the diaphragm and opposite ends carrying bond pads located adjacent the diaphragm. An opening in the dome permits wirebonder access to connect bond pads on the traces with terminal bond pads. A cover is installed over the connector and sensor.

Abstract: A semiconductor chip, which is preferably designed as a pressure sensor, has on its rear side one or more depressions in which the pressure is measured by correspondingly designed diaphragms which are coupled to piezosensitive circuits. The surface of the depressions and, optionally, the rear side of the semiconductor chip are coated with a protective layer which ensures that the semiconductor is protected from aggressive media. The protective layer thereby makes it possible to use the sensor universally in acids, lyes or hot gases.

Abstract: A temperature compensation circuit is connected to the output of a strain gauge pressure sensor having a wheatstone bridge arrangement. The signal from the wheatstone bridge sensor is amplified and converted by an instrumentation amplifier to produce a load current proportional to the pressure applied to the pressure sensor. The load current indicates the actual pressure applied to the pressure sensor. Constant voltage and current regulators compensate for variations in the load current from the pressure sensor which result from temperature changes.

Abstract: A pressure sensor comprises a pressure-sensitive coupler body 2 having one end provided with a diaphragm 8 and strain gage 9 stacked together, an intermediate body 3 containing a printed board 21 and encircling the strain gate 9, and a signal-detective coupler body 4 opposed to the pressure-sensitive coupler body 2 via the intermediate body 3 to define a closed chamber in the intermediate body 3. The printed board 21 and the strain gage 9 are electrically connected by terminal elements 13 extended from the strain gage 9 into slidable contact with conductive elements 25 attached to an edge of the printed board 21. Vibrations or impulses produced in the diaphragm 8 are therefore absorbed by a relative displacement between the terminal elements 13 and the conductive elements 25 to protect the printed board 21 against such vibrations or impulses.

Abstract: A pressure sensor comprises a substrate and a layer defining together with said substrate a pressure sensor cavity, said layer including a diaphragmlike area which is adapted to be acted upon by an external pressure. A micro-miniaturizable pressure sensor of the above-mentioned type, which is used for differential pressure measurement or for relative pressure measurement, is provided on the basis of the features that said cavity is followed by a channel which extends along the surface of said substrate, said channel comprising a layered structure including also the layer which also defines the diaphragmlike area of the pressure sensor, the ratio of the width of the channel to the thickness of the layered structure above the channel being smaller than the ratio of the smallest extension of the diaphragmlike area in the diaphragm plane to the thickness of the diaphragmlike area.

Abstract: To ensure insensitivity to electromagnetic interference and to charge influences from the oil fill and achieve good long-term stability, this pressure-measuring arrangement comprises: a pressure sensor having a base and an associated diaphragm with strain gages deposited thereon; a header of insulating material with leads and with an oil filler neck, said header of insulating material having the base mounted thereon, and said leads making electrical contacts to the strain gages; a metal body having a first central recess in a first cross-sectional surface, a second central recess in a second cross-sectional surface facing away from the first cross-sectional surface, and a hole connecting the first recess with the second recess, said first cross-sectional surface being tightly joined at its edge to the header of insulating material, and said first recess accommodating the substrate and diaphragm without touching them; an electrically conductive foil having an opening, said foil being disposed in the first rece

Abstract: A differential pressure transmitter having a differential pressure sensor, a temperature sensor and a static pressure sensor all provided on the semiconductor substrate of a single semiconductor chip. A reference resistor is provided in a part of the chip. Resistances of the differential pressure sensor and the reference resistor are compared periodically in order to determine the condition including service life of the differential pressure sensor.

Abstract: A modular pressure sensor has a pressure-sensing element, electrical terminals, interconnections, and a support substrate. The pressure-sensing element produces an electrical signal indicative of pressure at local contacts and the interconnections apply the signal to the electrical terminals. The electrical terminals are secured to the substrate and extend along a peripheral surface of the substrate. The modular pressure sensor can mount, with different orientations, to a header to form a pressure transducer.

Abstract: In a pressure sensor, the force is introduced onto a piezoresistive measuring element via a diaphragm and a punch. Since no exact mechanical adjustment between the diaphragm and the measuring element is necessary, various relatively inexpensive forms of diaphragm with different measuring sensitivity can be used. The punch and the piezoresistive measuring element can be pushed through an opening in the housing and pressed onto the diaphragm so as to provide an interlocking frictional connection between the punch and the measuring element.

Abstract: A form of pressure sensor diaphragm and method of making that allows for the formation of long rectangular plate structures in semiconducting material, especially Silicon. A plurality or multiplicity of sensors may be constructed on a single chip, thus providing for absolute and relative sensing of pressure on a single device.

Abstract: A pressure sensor includes a diaphragm assembly with a pair of diaphragms joined together along a rim and having spaced apart centers to form a cavity between them. A pressure input applies a pressurized fluid to external surfaces of the diaphragms. The diaphragm assembly is connected to a mounting block along a tab leaving the remainder of the diaphragm free from solid mounting. Deflection of the diaphragm assembly is sensed and is related to applied pressure.

Abstract: An oil pressure sender unit is disclosed which employs a two-part housing with a reinforced rubber diaphragm disposed between the two housing parts in order to isolate a pressurized oil cavity from a dry circuit cavity which contains the electrical components of the sender unit. In the preferred embodiment the reinforced diaphragm includes a peripheral lip which mates with a corresponding groove located within one part of the housing which is a metal base. The base has an axially extending inlet passage with a damper plug inserted therein which together defines a plurality of volume chambers that receive high pressurized pulsating oil at the inlet side and, because of its design, delivers a smooth flow of high pressurized oil to the underside of the diaphragm. This causes less wear on the electrical contacts that engage a two-sided circuit card which has a resistor circuit on one side and an on/off circuit on the opposing side.

Abstract: A pressure sensor for fluids includes first, second, third and fourth strain gauges disposed on a diaphragm with prescribed spacing so that the majority of current flowing through the first strain gauge has a predetermined direction and the majority of current flowing through each of the second, third and fourth strain gauges has a direction identical with or opposite to the predetermined direction, first and second conductors interconnecting the first and second strain gauges and the third and fourth strain gauges, and first and second voltage leads connected to the first and second conductors from the side identical with or opposite to the direction of a vector product determined by a vector in the direction of current flow through the conductors and a vector in a direction normal to the diaphragm. The configuration causes voltages produced in the conductors by the Hall effect to cancel out, thus making the pressure sensor immune to the effect of magnetic fields.

Abstract: An absolute pressure sensor subassembly includes a top cap bonded to a pressure sensor die and enclosing a reference vacuum. The subassembly is initially held in place within a housing by a vacuum or sublimeable solid adhesive while wire bonds from the subassembly to the housing leads are completed. A self-contained adhesive drop on the inner surface of the housing cover contacts the sensor subassembly when the cover is placed on the housing body and the sensor subassembly is supported by the adhesive drop.

Abstract: A differential pressure sensor (10) has a sensor die (16) attached to a stress isolation package base (12) with a bonding glass (27) having a similar coefficient of thermal expansion. The bonding glass, and alternately an aluminum layer, provides a hermetic seal between the stress isolation base and sensor die. Pressure is applied to the sensor die port (24). A plastic housing (14) is attached to the stress isolation base with an adhesive (29). A port (23) in the plastic housing is filled with a silicone gel (22). A second pressure source is transferred by way of the silicone gel to the sensor die. Any hostile chemical entering the via contacts the first surface of the sensor die to assert pressure against a transducer circuit (25) to generate the electrical signals representative of the applied pressure but are isolated from the sensitive interconnects by the hermetic seal.

Abstract: A modular pressure sensor has a pressure-sensing element, electrical terminals, interconnections, and a support substrate. The pressure-sensing element produces an electrical signal indicative of pressure at local contacts and the interconnections apply the signal to the electrical terminals. The electrical terminals are secured to the substrate and extend along a peripheral surface of the substrate. The modular pressure sensor can mount, with different orientations, to a header to form a pressure transducer.

Abstract: A vacuum priming diagnostic cartridge that can be inserted in place of an ordinary ink jet cartridge to diagnose and indicate vacuum condition in an ink jet maintenance station of a printer. The diagnostic cartridge includes a manifold that communicates vacuum from the maintenance station to a vacuum detector. The detector is responsive to the amount of vacuum generated by the maintenance station during a priming operation. A detector signal from the detector is directed to an interpolating driver circuit that acts on the detector signal and provides an indication of the vacuum level sensed by outputting an output signal to activate one or more indicators.

Abstract: A pressure sensor includes an electrically insulating material covering wires for transmitting an electrical signal generated by a semiconductor pressure-sensing unit, the joints between the wires and the pressure-sensing unit, and the joints between the wires and leads connected to the wires for leading the electrical signal to the outside of the body casing of the sensor. Thus, detection of pressure is possible even in an intense-vibration environment, and it is also possible to reduce influences by changes in temperature.

Abstract: A pressure sensor is provided in which the pressure sensing components are isolated from a portion of an attached buffer member which is connected to a fluid conduit. The offset characteristic of the pressure sensor isolates stress from being transmitted between an attached external fluid conduit and the sensitive components of the pressure sensor. One embodiment of the pressure sensor solders a fluid conduit structure to a buffer member that is attached to a pressure sensor die. An alternative embodiment of the present invention avoids the need for making solder connections between the sensor structure and external components by utilizing elastomeric conductors and pressure seals in association with the pressure sensor composite structure and first and second housing structures. These elastomeric conductors also provide improved stress isolation. The housing structures are used to compress to the seal and the elastomeric conductor against selected portions of the composite sensor.

Abstract: A pressure measurement system includes a diaphragm and a chamber for exposing one side of the diaphragm to a fluid. A force transducer is provided for measuring force exerted by the fluid on the one side of the diaphragm independent of diaphragm position. A ferromagnetic plate is attached to the diaphragm to enable removable coupling of the diaphragm with a magnet permanently attached to the force transducer.

Abstract: A pressure transducer is provided with a housing member that attaches to a rigid and generally planar member, such as a ceramic circuit board. The legs of the housing member can pass through holes in the circuit board or, alternatively, can attach to edges thereof. The legs of the housing are provided with bails which have steps shaped to seize the circuit board after the legs are flexed to permit insertion of the board between them. The housing is provided with an opening that is shaped to receive a media seal, a pressure sensor die and a conductive seal between a surface of the opening and a surface of the ceramic circuit board. When the circuit board is attached to the housing, the seals and the pressure sensor die are compressed therebetween to provide good fluid sealing association between the components and to also provide electrical communication between components on the pressure sensor die and components on the circuit board.

Abstract: A pulsed pressure sensor circuit (11) with increased sensitivity for measuring low pressures. A pulse generation circuit (12) is enabled by a microprocessor (28) to output a voltage pulse. The voltage pulse biases a pressure sensor (17) which has a port exposed to a pressure to be sensed. The pressure sensor (17) outputs a differential voltage which is proportional to the pressure at the port. The differential voltage is amplified by an amplifier (23) which has an output coupled to the microprocessor (28). A voltage divider circuit (26) is coupled to the pulse generation circuit (12) and has an output coupled to the microprocessor (28). The microprocessor (28) samples the voltages at the output of the amplifier (23) and the output of the voltage divider circuit (26). Microprocessor (28) then calculates the pressure using the sampled voltages and data stored in memory.

Abstract: A low range pressure sensor includes a base plate of brittle material, and a diaphragm plate mounted on the base plate and sealed around a periphery to the base plate. Pressures are introduced to cause the diaphragm to deflect toward the base plate, and the deflection of the diaphragm is sensed through strain gauges to provide an indication of the pressure. The diaphragm is provided with a plurality of individual support posts on a side facing the base plate, so that when the diaphragm is deflected toward the base plate under high overpressures the support posts will support the diaphragm against movement to avoid failure or breakage of the diaphragm. The number of support posts can be varied as desired.

Abstract: A resistive strain gauge pressure sensor including upper and lower housings coacting to define a pressure chamber within the housing. A board member assembly is clamped between the housings and defines a diaphragm portion which extends across the pressure chamber to divide the pressure chamber into upper and lower chamber portions. The board member assembly includes a relatively thin plate member, including a diaphragm portion, and a relatively thick support member bonded to the upper face of the thin plate member and including an annular portion positioned in surrounding relation to the diaphragm portion. The circuitry of the sensor is screen printed onto the lower face of the plate member and includes the various resistor elements of the strain gauge assembly, the various elements of the conditioning circuit receiving the output of the strain gauge assembly, and the various further leads required to connect the circuitry elements to the terminals of the sensor.

Abstract: A resistive strain gauge pressure sensor including upper and lower housings coacting to define a pressure chamber within the housing. A board member is clamped between the housings and defines a diaphragm portion which extends across the pressure chamber to divide the pressure chamber into upper and lower chamber portions. All of the circuitry of the sensor is screen printed onto the lower planar face of the board member including the various resistor elements of the strain gauge assembly, the various elements of the conditioning circuit receiving the output of the strain gauge assembly, and the various further leads required to connect the circuitry elements to the terminals of the sensor. The sensor terminals are provided by a plurality of connector pins extending downwardly through the board member for connection at their respective lower ends to the circuitry provided on the lower face of the board member.

Abstract: A pressure sensitive sensor in which a pressure detecting convex portion is formed on the surface of a pressure-sensitive and conductive elastomer sheet, and an electrode is arranged on the reverse side of the pressure detecting convex portion for making it possible to detect a pressure acting in the direction in parallel or in the oblique direction with a slight angle with respect to the surface of a pressure-sensitive and conductive elastomer component. In addition, for obtaining a high detection density, a contact is made up with a face-defined body defining a pressure face, and a contacting convex portion is made to protrude from the face-defined body, where the contact is resiliently supported onto the pressure-sensitive elastomer sheet.

Abstract: A silicon micro sensor including a silicon substrate, a support element formed over an etched portion of the silicon substrate and a sensor element formed on the support element wherein the support element has a double layered structure including a silicon oxide film formed on the silicon substrate using the thermal oxidization method and an aluminum oxide film formed on the silicon oxide film using the sputtering method.

Abstract: A semiconductor pressure sensor according to the invention comprises a first semiconductor substrate and a second semiconductor substrate, disposed around the first substrate, so that signals obtained by the semiconductor pressure sensor under static or differential pressure conditions can be properly corrected and both static and differential pressures can be detected accurately and reliably measured on the same semiconductor substrates. Another object of the invention is provide a semiconductor pressure sensor which utilizes a single substrate with an aperture, which acts as a pressure overload stop mechanism, and which does not suffer from any effects of diaphragm deformation as a result of possible pressure overload.

Abstract: A transmitter with a flame arresting header senses a pressure of a process fluid with a diaphragm which is sealed to the header. The diaphragm transfers the pressure of the process fluid acting an outer surface of the diaphragm to a fill fluid that isolates an inner surface of the diaphragm, and a pressure sensor enclosed in the transmitter senses the pressure of the fill fluid providing an output representative of the pressure of the process fluid. The header includes a chamber on the header's outer face and a passageway extending from the chamber to a tapered opening inside the transmitter with a first portion adjacent to the tapered opening shaped to receive an inlet tube leading to the sensor and a second flame isolating portion open to the chamber. The fill fluid fills the chamber, the passageway, and the inlet tube and is sealed in with a tapered seal pressed into the tapered opening around the inlet tube.

Abstract: The invention relates to sensors having field effect semiconductors. The sensor of the invention comprises a ring oscillator constituted by an odd number of CMOS inverters disposed in a zone sensitive to the physical property to be measured. In order to increase the sensitivity of the sensor, the N channel of the NMOS transistor in each CMOS inverter is disposed perpendicularly to the P channel of the PMOS transistor.

Abstract: This invention relates to a semiconductor sensor for detecting external physical forces, such as acceleration, contact pressures, air pressures, mechanical vibrations, etc. The semiconductor sensor according to this invention is characterized by the use of compound semiconductors of high piezoelectricity, such as GaAs, etc. Conventionally sensors of the cantilever type, diaphragm type, etc. are made of silicon. These prior art sensors have low detection sensitivity, and their characteristics tend to deteriorate. The sensor according to this invention is made of GaAs, which has high piezoelectricity and can retain good characteristics of the semiconductor even at high temperatures and includes a field-effect transistor formed on the GaAs for sensing a stress. The FET is driven by a constant current or a constant voltage so as to detect a change of an electrical characteristic (e.g., threshold characteristic) due to a stress.

Abstract: A semiconductor pressure sensor assembly, comprising a receptacle having a floor and including a first cavity recessed within a first portion of the floor, and a second cavity recessed within a second portion of the floor and connected to the first cavity at a first junction. A semiconductor pressure sensor is within the first cavity, and a plurality of bonding pads are disposed about a periphery of a top surface of the pressure sensor chip other than at a location of the first junction, a plurality of external conducting terminals are disposed about a periphery of the receptacle other than at the location of the first junction, and a plurality of wires connect the external conducting terminals to respective ones of the bonding pads. A gelatinous material is within the first and second cavities, and the second cavity serves as a first work region from which an excess of the gelatinous material within the first cavity can be removed.

Abstract: A control device for fluid containers (16) of a flexible material, particularly for controlling the level of stomi bags, comprises an elastic resistance element (10) having an electric resistance which changes by stretching of the element, which is adapted to be fixedly connected with the container wall at the ends thereof to extend over an extensible portion (17) of the container wall. Means (12) are provided for connecting an alarm means (19) reacting to a change in the resistance of the resistance element.

Abstract: A biomedical pressure sensor having a pressure sensing diaphragm is provided with a distensible membrane overlying the diaphragm, and the diaphragm is provided with one or more holes. During normal operation, externally applied pressure forces the membrane against the diaphragm so that the membrane and diaphragm deform under pressure as a unit and transmit pressure-applied forces to a force transducer within the probe housing. When a reference pressure exceeding the externally applied pressure is supplied within the probe housing, such reference pressure passes through the hole in the diaphragm and forces the membrane away from the diaphragm, thereby isolating the diaphragm from the externally applied pressure and bringing the diaphragm to a zero-differential pressure condition. Use of a hole in the diaphragm permits an extremely compact construction.

Abstract: An apparatus and method including a load cell mounting apparatus movably mounted on a load cell which applies either of two types of loads to the load cell as one type of load. The apparatus and method for applying either a tensile load or a compressive load to a load cell as a tensile load; and a tong assembly with such apparatus or in another aspect, for applying either a tensile load or a compressive load to a load cell as a compressive load; and, a tong assembly with such apparatus.

Abstract: A capillary rheometer including a plunger pressure transducer assembly which contains a liquid metal fill capillary passage therein. When the plunger is urged downward onto the melted polymer, a diaphragm at the end of the plunger senses the pressure within the melted polymer and transmits this pressure to the liquid metal fill. An additional diaphragm disposed in the opposite end of the plunger pressure transducer assembly senses this transmitted pressure within the liquid metal fill for an accurate indication of the pressure therein.

Abstract: A pressure transducer (50) of the type utilizing a diaphragm (8) with strain sensitive elements (14) formed in the diaphragm surface where the strain sensitive elements (14) are connected to an electronics assembly (4) to produce an electrical output in response to deflection of the diaphragm (8). A diaphragm assembly (26) is bonded to an intermediate support member (28) which is in turn bonded to a main support member (32) which is joined to a support collar (42) and hermetically sealed thereto with a sealing glass (40) where each element (2, 28, 32, 42) has a substantially matched coefficient of thermal expansion so as to reduce any induced thermal stresses and resultant measurement errors where the sealing glass (40) and the support collar (42) have a greater coefficient to produce a compressive type seal at high temperature.

Abstract: A diaphragm type pressure sensor comprises a transducer main body and a protective cover. The main body has a diaphragm portion, a support portion supporting the periphery of the diaphragm portion, and a trunk portion having a shoulder surface which surrounds the support portion and which forms a step surrounding the support portion. The support portion projects upwardly from the inner periphery of the shoulder surface, and is separated by the shoulder surface from the protective cover fitted over the trunk portion. Therefore, the diaphragm portion is not easily influenced by an external force applied to the trunk portion from the protective cover. The main body may further has an abutting surface which forms another step surrounding the support portion, and which abuts against a lower end of the protective cover.

Abstract: A resistive strain gauge pressure sensor including upper and lower housings coacting to define a pressure chamber within the housing. A board member is clamped between the housings and defines a diaphragm portion which extends across the pressure chamber to divide the pressure chamber into upper and lower chamber portions. All of the circuitry of the sensor is screen printed onto the lower planar face of the board member including the various resistor elements of the strain gauge assembly, the various elements of the conditioning circuit receiving the output of the strain gauge assembly, and the various further leads required to connect the circuitry elements to the terminals of the sensor. The sensor terminals are provided by a plurality of connector pins extending downwardly through the board member for connection at their respective lower ends to the circuitry provided on the lower face of the board member.

Abstract: A cartridge forming a pressure measuring device is composed of main casing, a bushing detachably screwed to the casing and a coupling piece detachably screwed to the casing. The coupling piece has a plug which serves to establish hydraulic connection with some appliance to permit hydraulic fluid to act on a diaphragm configured as an integral thin wall of the coupling piece. A strain gauge sensor is mounted on the diaphragm and produces electrical signals on leads as the diaphragm deflects as a result of exposure to the pressure fluid. An amplifier serves to amplify the signals from the sensor for further processing and utilisation. The amplifier is mounted to the coupling piece with the aid of elongate conductive pins which also serve to connect the sensor leads to the amplifier.

Abstract: A voltage-to-digital converter comprising a storage circuit for providing a storage capacitance with a plurality of selectable magnitudes. The storage circuit provides a charge output representative of applied voltage input signals and the selected capacitive magnitude. A charge accumulation circuit is coupled to the charge output. The total charge accumulated is proportional to the integral of the amount of charge discharged from the storage circuit. The charge accumulation circuit provides a balance output representative of a comparison of the accumulated charge and a reference charge.

Abstract: A precision pressure sensor in the form of a load cell has a mounting ring closed at one end by an end wall which has axially outwardly facing dead-end holes therein to form sensor beams each having an axially outwardly facing plane surface to which strain gages are bonded. The dead-end holes have bottoms forming sensor membranes. Opposite the closed end the mounting ring encloses a cavity forming a sensor space which is closed by a closure plug that simultaneously has a bore for admitting fluid under pressure to be measured into the sensor space. A ring groove in the end wall has approximately radially sloping surfaces which together with the dead-end holes determine the minimum cross-section of the measuring beams. The ring groove also determines the minimum thickness of the sensor membranes.

Abstract: A pressure sensing device comprising a body member and a cap member constructed with a simple snap-fit for assembly and disassembly. The assembled device permits non-bonded contact of conductive leads with electrically conductive elements of a pressure-responsive transducer die for sensing pressure and transmitting signals generated by the force of a pressurized medium in hollow a chamber of the body member. A seal provides for functional reliability independent of thermal cycling stresses.

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: The invention relates to a pressure or force sensor having an axially symmetrical, force-receiving circular plate spring which has a reinforced edge region (5) which serves as a support on a carrier, said spring being provided with strain gauges. To prevent radial sliding motions between the carrier and the circular plate spring the carrier is fitted at the reinforced edge region of the circular plate spring in an annular zone, in which the radial expansion is substantially zero.

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

Abstract: A first substrate having a working region, a flexible region, and a fixed region is prepared. Resistance elements are formed within the flexible region on a first surface of this substrate. A portion of the first substrate is removed. Thus, the flexible region is allowed to have flexibility. A second substrate is connected to a second surface of the first substrate. The second substrate is cut later into two portions of a working portion and a pedestal. The working portion is connected to the working region of the first substrate, and the pedestal is connected to the fixed region of the first substrate. In order to control displacements in upward and downward directions of the working portion, control substrates are further connected. A force applied to the working portion by acceleration or magnetism is detected as changes in the resistance values of the resistance elements.

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: An electric transducer has a casing with a plurality of walls defining a pair of chambers, and one of the walls interposed between the chambers defines a diaphragm for deflection in response to fluid pressure in one of the chambers. A strain gauge disposed on the one wall in the other of the chambers spans the diaphragm for conjoint deflection therewith to establish an output voltage correlative with the diaphragm deflection, and an electronic amplifier in the other chamber is connected in circuit relation with the strain gauge for amplifying the output voltage.

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