Abstract: The invention relates to a pressure sensor comprising a housing (12), a membrane (26) arranged in said housing and which can be deflected by the pressure to be measured, a light source (LED) having an optical axis, a light detector having an optical axis and a light blocker (36) that is coupled to the membrane and that can be deflected thereby, the blocker being arranged in the beam path of the light source. The light source and the light detector are arranged inside the housing (12), wherein their optical axes lie parallel to one another. A first prism (40) is assigned to the light source and a second prism (42) is assigned to the light detector in such a way that an uninterrupted beam path from the light source through both prisms to the light detector is obtained. To this end, the light blocker (36) is arranged between the two prisms.

Abstract: A pressure sensor device for producing a signal indicative of a pressure of a fluid to be monitored, including a housing having a fluid conduit for receiving the fluid to be monitored and a diaphragm positioned at an end of the fluid conduit. The diaphragm includes at least first and second portions, wherein a thickness of the first portion is less than a thickness of the second portion. A transducer is bonded to a surface of the first portion of the diaphragm and including piezoresistive elements for sending the signal. Preferred is a circular second portion and an annular first portion around the outer edge of the second portion. The housing is preferably tubular and includes an annular shoulder for mounting the diaphragm, along with an annular groove on the outer surface of the first portion and connecting the first portion to the annular shoulder.

Abstract: An arrangement for measuring the true position of a diaphragm within a diaphragm valve assembly utilizes a thin conductive element disposed in the valve between the diaphragm membrane and the actuator. The conductive element and the valve body are then used as the plates of a parallel plate capacitor, where the measured capacitance will vary as a function of the position of the diaphragm mambrane, having a first value when the diaphragm is in the “open” position and a second value when the diaphragm is in the “closed” position. Position values between the “open” and “closed” positions can also be determined, as well as the presence of different fluids within the valve body when the valve is in the “open” position.

Abstract: Several associated techniques and fiber optic constructions are disclosed to protect a diaphragm type fiber optic cylinder pressure sensor from the effects of maximum under hood temperatures and to minimize errors associated with rapidly changing under hood and engine temperatures. The techniques include electronic compensation in response to temperature change, fuel system cooling of the optoelectronic interface, construction of the interface and construction of the sensor tip.

Abstract: A pressure transducer designed to transform static pressure or dynamic pressure applied to a diaphragm into a corresponding electrical signal and a method of manufacturing the same are provided. The transducer includes a fixed electrode formed in an upper surface of a substrate and a moving electrode provided in the diaphragm disposed above the fixed electrode through a cavity. The substrate has formed in the bottom thereof at least one hole which is used in a manufacturing process for removing a sacrificial layer formed between the diaphragm and the upper surface of the substrate in dry etching to form the cavity.

Abstract: A high pressure sensor is provided with a single-piece pressure port machined from stainless steel and has no internal gaskets or seals. A housing surrounds the pressure port along a portion of its axial length. The housing and pressure port have mating configurations that prevent axial rotation when the pressure port is inserted into the assembled position in the housing. A retaining ring locks the pressure port axially with respect to the housing and is fixed in place by a fixative, such as epoxy.

Abstract: A port fitting (102) is formed with a closed, pedestal end forming a diaphragm (102a) on which a strain gauge sensor is mounted. A support member (106) is received on the pedestal end and is formed with a flat end wall (106a) having an aperture (106d) aligned with the sensor. A circuit assembly (108) is bonded to the flat end wall and the sensor wire bonded to the electronic circuit. A cover member (114) placed on the support member, is provided with a cavity for a metal shield member (118) fitted inside the cover member before assembly. The shield member is formed with spring members (118b) extending outside the perimeter of the cover member. The cover member is formed with circular cavities (114d) extending in an axial direction to provide seating for contact spring members (117), making electronic contact to the sensor electronics and protruding beyond the body of the cover member. The cover member is also fitted with a circular elastomer gasket member (116), providing an environmental seal.

Abstract: A pressure sensor is mounted integrally in a hydraulic valve body. The sensor has a base which extends into a bore formed in the valve body. The valve body bore is in communication with a pressurized hydraulic fluid. A first circumferential groove formed in the sensor base carries an O-ring which forms a seal between the sensor and the wall of the valve body bore. A second circumferential groove formed in the sensor base carries a spring ring which extends into a corresponding groove formed in the wall of the valve body groove. The spring ring cooperates with the sensor base and valve body bore grooves to retain the sensor in the valve body bore.

Abstract: The present invention relates to compact solid state silicon-based condenser microphone systems suitable for batch production. The combination of the different elements forming the microphone system is easier and more economical to manufacture compared to any other system disclosed in prior art. In addition the invention is compatible with electronic equipment manufacturing processes, such as SMD pick and place techniques. The invention uses a transducer chip comprising a chamber, a diaphragm that is positioned at the first lower surface and covering the second opening of the transducer chip. The transducer chip is flip-chip mounted onto a post-processed chip also comprising a chamber. The microphone system can be electrically connected to an external substrate by conventional techniques such as wire bonding.

Abstract: A pressure sensor includes a housing, an interior chamber of which is sealed by a diaphragm, and a flexible measuring element, which is positioned separately. In addition, the pressure sensor includes a transmission element, which is formed as a chip and is used to transmit force from the diaphragm to the measuring element. In response to a selected deformation of the measuring element, a stop element comes into contact with a region of the transmission element and opposes the applied force. Therefore, it forms an overload protection. The stop element may be configured as a bending bar and/or form a second measuring element, the first measuring element being configured to measure relatively low pressures, and the second measuring element or stop element being configured to measure relatively high pressures. The pressure sensor thus provides a plurality of measuring ranges.

Abstract: A pressure measuring device includes a housing which retains a pressure responsive element interconnected to an indicating member that moves relative to a dial face when a change of pressure is detected. A peripheral bumper is mounted to the housing exterior, the bumper including an extending portion which creates a discontinuous path for shock or impact loads applied to the bumper relative to a continual movement mechanism. The housing can further include a discontinuous region imposed in an engagement portion of the housing, the engagement portion permitting the housing to be directly attached to an inflatable blood pressure sleeve.

Abstract: A micromechanical differential pressure sensor device for measuring a pressure difference between two mutually separated spaces or media, in which two absolute pressure measuring devices are monolithically integrated on a single support substrate, in particular on a semiconductor chip. The absolute pressure measuring devices are preferably fabricated by surface micromachining.

Abstract: A method for manufacturing a sensor component, in particular, a thin-film high-pressure sensor, as well as a sensor component, is described, in which at least one measuring element, in particular an expansion measuring strip is arranged on a membrane, and separated from the membrane through an electrically insulating film, the measuring element being arranged on an electrically insulating substrate, which is mounted in a subsequent step onto the membrane on the side that faces away from the measuring element, so that the electrically insulating substrate forms the electrically insulating film. The electrically insulating substrate performs both a carrier function during the application of the expansion measuring strip to the substrate as well as an insulation function after the mounting of the substrate onto the membrane. In this way, the application of a separate insulation film made of silicon dioxide becomes unnecessary.

Abstract: A port fitting is formed with a closed, pedestal end forming a diaphragm on which a strain gauge sensor is mounted. A support member is received on the pedestal end and is formed with a flat end wall having an aperture aligned with the sensor. A portion of a flexible circuit assembly is bonded to the flat end wall with a connector disposed over the support member. A tubular outer housing is fitted over the several components and its bottom portion is welded to the port fitting while its top portion places a selected load on an O-ring received about the connector as well as internal components of the transducer. In one embodiment, a loading washer (72a) is disposed over the O-ring on a first portion (70a) of a two portion connector (70) and retained by a second connector portion (70b). Protrusions (76a1) formed on the tubular housing (76) pass through cut-outs in the second connector portion to place a load on the loading washer.

Abstract: A pressure sensor that is particularly suitable for the food industry and the measuring accuracy of which is stable over a long time, having a diaphragm seal with a separating diaphragm on which a pressure to be measured acts and having a ceramic measuring cell which is connected to the diaphragm seal exclusively by inorganic materials, is provided, in which sensor the separating diaphragm and all further sensor components coming into contact during measurement with a medium of which the pressure is to be measured are metallic.

Abstract: A pressure sensing unit has a pressure responsive member, a pressure sensor, and a hydraulic connector hydraulically connecting the pressure responsive member with the pressure sensor to produce an indication of sensed pressure. The hydraulic connector includes a tubular member and a longitudinal insert in the tubular member with hydraulic fluid in the tubular member between the insert and the member. The tubular member, the insert and the hydraulic fluid and the dimensions of the tubular member and the insert are such that the hydraulic fluid transmitted to the pressure sensor is substantially independent of temperature changes.

Abstract: An acceleration sensor includes a deflectable pressure measuring diaphragm and a counter-structure, which is deflectable as against the pressure measuring diaphragm. The acceleration sensor includes a detection means for detecting a deflection of the pressure measuring diaphragm as against the counter-structure. Further, a test mass is connected to the pressure measuring diaphragm or the counter-structure in order to be deflected from an idle position depending on an acceleration applied. The deflection of the test mass results in a change of the distance between the pressure measuring diaphragm and the counter-structure, which is detectable by the detection means.

Abstract: A fluid-filled elastic hollow body 2, includes a pressure sensor 4 for detecting the pressure of the fluid in the elastic hollow body, and an adapter 6 for coupling the elastic hollow body to an external movable member. The elastic hollow body 2, having a hollow sphere portion 2a having a roughly constant wall thickness, is deformed when an external contact load is applied causing a rise in its inner pressure detected by the pressure sensor 4. The invention provides: (1) that the sensor can accurately measure a contact load without being influenced by a change in direction of force measured; (2) that it can be attached easily and measure a load immediately after attachment; (3) that it is resistant against instantaneous shock load; (4) that it can easily model a substance when it comes in contact therewith; and (5) that its sensitivity does not deteriorate.

Abstract: A pressure mediator includes a base body; a divider diaphragm system having a first divider diaphragm and a second divider diaphragm, between which an intermediate chamber is enclosed in pressuretight fashion, in which the first surface of the first divider diaphragm, remote from the intermediate chamber, can be acted upon by the pressure prevailing in the first medium, and the first surface of the second divider diaphragm, remote from the intermediate chamber, is oriented toward the base body and is secured by its peripheral region to the base body, forming a pressure chamber between the base body and the second divider diaphragm, and the pressure chamber can be filled with the second medium and has a pressure chamber opening, through which the pressure can be transmitted by means of the second medium, and an exertion of pressure of the first divider diaphragm can also be transmitted to the second divider diaphragm via the intermediate volume; and having a sensor, for monitoring a property of the intermediat

Abstract: A semiconductor sensor chip is interposed between a sensor case and a housing. A first pressure is introduced from the sensor case and applied to a rear surface of the sensor chip, while a second pressure is introduced from the housing and applied to a front surface of the sensor chip. The sensor chip detects a pressure difference between the first and the second pressures and converts it into an electrical signal. The sensor chip is hermetically mounted in a depressed portion formed in the sensor case by charging a sealing material from holes formed around the depressed portion. The charging holes are positioned between terminals electrically connecting the sensor chip to an outside circuit to avoid enlarging the pressure sensor size by forming the charging holes.

Abstract: The invention concerns a pressure sensor (1), able to operate at high temperature and measure the pressure of a hostile medium, comprising: a sensing element (4) integrating a membrane (8) in monocrystalline silicon carbide, made by micro-machining a substrate in polycrystalline silicon carbide, a first surface of membrane (8) intended to contact said medium, a second surface of membrane (8) comprising membrane deformation detection means (9) connected to electric contacts (10) to connect electric connection means (11), the surfaces of sensing element (4) contacting said medium being chemically inert to this medium; a carrier (5) to support sensing element (4) so that said first surface of membrane (8) may be contacted with said medium and the second surface of membrane (8) may be shielded from said medium, carrier (5) being in polycrystalline silicon carbide; a seal strip (6), in material containing silicon carbide, brazed between carrier (5) and sensing element (4) to protect the second surface of membra

Abstract: A pressure sensor includes a pressure sensor element that is provided with a pressure sensor membrane. The pressure sensor element is held in a receiving part in a defined position during operation within a permissible operating pressure range by a spring element. When the permissible range is exceeded, a relative movement, acting against the spring force, between the pressure sensor element and the receiving part takes place, thereby increasing the volume of the space immediately upstream of the pressure sensor membrane. The design allows for a limitation of the pressure and for an effective protection of the pressure sensor membrane when the liquid is frozen.

Abstract: A pressure transducer which has a closed chamber which is full of oil or other non-compressible liquid. Pressure communicates with a diaphragm which defines one side of the closed chamber and the pressure communicates via the oil with a pressure sensor which is mounted within the oil spaced from the diaphragm. The liquid entered the closed chamber through a inlet hole with a selected volume driven into the closed chamber by a ball which is forcefully driven a selected distance into the inlet hole before stopping at the end of the inlet hole against a physical stop.

Abstract: A capacitor industrial process control transmitter includes a three-phase excitation circuit to charge a sensing capacitor and a compensation capacitor of the transmitter and transfer charges to an integrator. The sensing capacitor is charged during the first phase. During the second phase, the voltage to the sensing capacitor is reversed, and the charge on the sensing capacitor is pumped to the integrator. Also, the compensation capacitor is charged with the reversed voltage during the second phase. During the third phase, the voltage to the compensation capacitor is changed, and the charge on the compensation capacitor is pumped to the integrator.

Abstract: A pressure-measuring cell having a base and a diaphragm positioned on the base is deformed by a pressure being measured. A temperature-measuring sensor is positioned between the diaphragm and the base preferably embedded in a material layer that seals a compartment. The diaphragm is preferably made of a ceramic and the material layer is preferably made of a glass.

Abstract: A port fitting is formed with a closed, pedestal end forming a diaphragm on which a strain gauge sensor is mounted. A support member is received on the pedestal end and is formed with a flat end wall having an aperture aligned with the sensor. A portion of a flexible circuit assembly is bonded to the flat end wall with a connector disposed over the support member. A tubular outer housing is fitted over the several components and its bottom portion is welded to the port fitting while its top portion places a selected load on an O-ring received about the connector as well as internal components of the transducer. In one embodiment, a loading washer (72a) is disposed over the O-ring on a first portion (70a) of a two portion connector (70) and retained by a second connector portion (70b). Protrusions (76a1) formed on the tubular housing (76) pass through cut-outs in the second connector portion to place a load on the loading washer.

Abstract: A port fitting is formed with a closed, pedestal end forming a diaphragm on which a strain gauge sensor is mounted. A support member is received on the pedestal end and is formed with a flat end wall having an aperture aligned with the sensor. A portion of a flexible circuit assembly is bonded to the flat end wall with a connector disposed over the support member. A tubular outer housing is fitted over the several components and its bottom portion is welded to the port fitting while its top portion places a selected load on an O-ring received about the connector as well as internal components of the transducer. In one embodiment, a loading washer (72a) is disposed over the O-ring on a first portion (70a) of a two portion connector (70) and retained by a second connector portion (70b). Protrusions (76a1) formed on the tubular housing (76) pass through cut-outs in the second connector portion to place a load on the loading washer.

Abstract: A port fitting is formed with a closed, pedestal end forming a diaphragm on which a strain gauge sensor is mounted. A support member is received on the pedestal end and is formed with a flat end wall having an aperture aligned with the sensor. A portion of a flexible circuit assembly is bonded to the flat end wall with a connector disposed over the support member. A tubular outer housing is fitted over the several components and its bottom portion is welded to the port fitting while its top portion places a selected load on an O-ring received about the connector as well as internal components of the transducer. In one embodiment, a loading washer (72a) is disposed over the O-ring on a first portion (70a) of a two portion connector (70) and retained by a second connector portion (70b). Protrusions (76a1) formed on the tubular housing (76) pass through cut-outs in the second connector portion to place a load on the loading washer.

Abstract: A chamber in the interior of a housing communicates with the environment of the housing by means of a gas esxchange path, wherein a filter element with a hydrophobic and/or hydrophobicized, nanoporous material is placed in the gas exchange path. The chamber serves, e.g. to accomodate electronic circuitry, or it is chamed as a reference pressure chamber of a relative pressure sensor. The relative pressure sensor according to the present invention for capturing a measured pressure with respect to a reference pressure comprises a reference pressure path 23 which extends between a surface which can be exposed to the reference pressure and an opening in a reference pressure chamber 22, a filter element 30 which is arranged in the reference pressure path comprising a hydrophobic or hydrophobicized, nanoporous material. The filter element allows pressure compensation on account of its permeability to N2 and O2, while water molecules are selectively blocked.

Abstract: A port fitting is formed with a closed, pedestal end forming a diaphragm on which a strain gauge sensor is mounted. A support member is received on the pedestal end and is formed with a flat end wall having an aperture aligned with the sensor. A portion of a flexible circuit assembly is bonded to the flat end wall with a connector disposed over the support member. A tubular outer housing is fitted over the several components and its bottom portion is welded to the port fitting while its top portion places a selected load on an O-ring received about the connector as well as internal components of the transducer. In one embodiment, a loading washer (72a) is disposed over the O-ring on a first portion (70a) of a two portion connector (70) and retained by a second connector portion (70b). Protrusions (76a1) formed on the tubular housing (76) pass through cut-outs in the second connector portion to place a load on the loading washer.

Abstract: In a load detecting device, a hermetically sealed sensor chamber is constituted by a sensor head, a bellows, a housing and a stem. A sensor chip for detecting pressure is housed in the sensor chamber that is filled up with liquid. When load is applied to the sensor head, the bellows contracts axially to vary pressure of the liquid. The sensor chip senses the pressure of the liquid so that the load applied to the sensor chamber is detected with higher detecting accuracy.

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

Abstract: A pressure transmitter with a fluid isolator that includes a sensor tube and a fill tube that have “D” shaped ends that connect together in a port internal to the transmitter. The shaped ends can be brazed into the port for sealing. Fitting both the sensor tube and the fill tube in the same port provides a low cost isolator with reduced isolator liquid volume. The fluid isolator has an isolator diaphragm with a central diaphragm region overlying a central backing plate that includes a annular groove. The annular groove avoids slow response of the isolator after an overpressure condition.

Abstract: A pressure sensor element for mounting in a connecting element comprises an isolator body with a laterally projecting membrane. The laterally projecting membrane covering an opening of a passage through which the pressure present at the surface of the membrane is conveyed to a pressure transducer element by means of a hydraulic fluid. In order to mount the pressure sensor element, it is secured in a mounting aperture of the connecting element. The projecting perimeter of the membrane is secured to the surface surrounding the mounting aperture of the connecting element by means of a continuous seam. A membrane type ring in combination with a conventional membrane may be substituted for the projecting membrane, wherein the membrane type ring covers the gap between the pressure sensor element and the adapter element.

Abstract: There is provided an improved load transducer type metal diaphragm pressure sensor capable of accurately sensing pressures, which is low in cost, easy to fabricate, and suitable for mass-production. The metal diaphragm pressure sensor (1) comprises a disc-shaped metal diaphragm (2) having a pressure element to which a fluid pressure is applied; a strip-shaped beam member (4) of silicone spanning the diaphragm in a direction of the diameter of the diaphragm, said beam member (4) having electrically insulating insulation bases (3) at each of its ends and in its midsection, and being bonded to the metal diaphragm at each of its ends via the insulation bases (3a, 3b); a pin-shaped pivot (5) connected between the midsection of the beam member and the midsection of the metal diaphragm via the insulation base (3c); and a bridge circuit containing diffused resistor elements (6a, 6a′).

Abstract: A device for measuring the pressure of blood in a pipe (44) of an extracoporeal blood cicuit, includes a pressure measurement section (46) having a compartment (58) which is delimited especially by a main wall (64) and by a secondary wall (65) facing it. The two walls (64, 65) have a hole (66, 84) which is closed by a closure element (68, 86) which can be elastically deformed under the effect of the blood pressure, and the compartment (58) has a spacer (94) which transmits the movements from the closure element (86) of the secondary wall (65) to the closure element (68) of the main wall (64), so that a load sensor (56) can measure a force which corresponds to a so-called “negative” blood pressure.

Abstract: The invention relates to a pressure sensor consisting of a chip (11) which is mounted on a support wall (10) and which is provided with a resistance unit consisting of strip conductors and being arranged at the lower side (13) of a substrate (12). Said lower side faces the support wall (10). The resistance unit is located on a thin membrane (18). A recess (19) is located behind said membrane. The chip (11) is fixed on the support wall (10) by means of an elastic intermediate layer (26). The electrical components of the chip are protectively arranged between the substrate (12) and the support wall (10). The invention provides for an extremely flat sensor unit without additional sensor housing. Said sensor unit can even be used for measuring pressures in electrically conductive mediums.

Abstract: A test assembly includes a valve and a piston received in a casing. The valve includes a main passage and a flexible seal film is mounted to an end of the valve. The seal film seals the main passage and has two apertures. A radial passage is defined through the valve and communicates with the main passage. A sub-passage is located in parallel with the main passage and communicates with the radial passage and one of the apertures of the seal film. A control member is rotatably and radially inserted in the valve and has a first path radially through the shank of the control member and communicates with the main passage. A second path is defined in half way of the shank and communicates with the first passage.

Abstract: A low-mass pointer element for a pressure measuring mechanism is made from a lightweight plastic paper material and includes a center hub having a through aperture which is sized to accommodate a rotatable shaft end of the pressure measuring mechanism. An indicating end of the pointer element is sloped downwardly toward a dial face relative to the center hub to prevent parallax along with a counterbalancing portion. The indicating end is inwardly tapered to a flattened distal end to provide equivalent stiffness, but with considerably less mass so as to significantly reduce stress loads on a corresponding movement mechanism.

Abstract: A barometric pressure sensor including a base layer, a sensor layer and a reference layer. The base layer has a passageway between a pressure inlet and a mounting face. The sensor layer is bonded by an insulating bond to the mounting face and includes a conductive diaphragm. The reference layer is mounted on the sensor layer to form a reference vacuum cavity. The reference layer includes a conducting surface facing the conductive diaphragm across the reference vacuum cavity to form a pressure sensing capacitor.

Abstract: A differential pressure sensor has a first and a second measuring chamber. Each measuring chamber is limited by a rigid carrier plate and a diaphragm plate, which is formed in the region of the measuring chamber as a pressure-sensitive measuring diaphragm. To design the differential pressure sensor to be resistant to overloading, the carrier plate is arranged between a first and a second diaphragm plate and has congruent concave depressions on opposite sides in the plane of the plate. The depressions are connected to one another by a central duct, penetrating the carrier plate perpendicularly to the plane of the plates. In the region of the measuring chambers, the diaphragm plates are formed congruently in relation to the depressions as pressure-sensitive measuring diaphragms. The measuring chambers are coupled to one another by a ram guided axially movably in the duct.

Abstract: An electronic control apparatus contained within a housing comprises a printed circuit board with both electronic components and at least one pressure sensor. A pressure conduit is used to channel a pressure medium to be measured to the pressure sensor. The perimeter edge of the pressure conduit facing the pressure sensor is hermetically sealed around the pressure sensor, so that the other components on the printed circuit board, as well as the housing itself, are not subjected to the pressure medium to be measured.

Abstract: A pressure sensor includes a sensor device and a diaphragm. The diaphragm is exposed to a fluid, a pressure relative to which is detected using the sensor device. The diaphragm is made of a material having a pitting index, which is defined by the equation, (Cr+3.3Mo+20N), of 50 or greater and Ni content of 30 weight % or greater to prevent the diaphragm from corroding due to the fluid.

Abstract: The present invention lessens the amount of air entering between mating membranes of a pressure sensor. The pressure sensor of the present invention includes a transducer portion and separate patient or medical fluid transfer portion or dome. The transducer portion is reusable and the dome is disposable. The dome defines a fluid flow chamber that is bounded on one side by a dome membrane. Likewise, the transducer is mounted inside a housing, wherein the housing defines a surface that holds a transducer membrane. The two membranes mate when the dome is fitted onto the transducer housing. The pressure sensor enhances the seal between the mated membranes by creating higher localized contact stresses. The pressure sensor also reduces the amount of gas that permeates from the fluid chamber across the dome membrane and between the interface by making the dome membrane from a material having a low vapor transmission.

Abstract: A direct passage manometer includes a body into which at least two rectilinear channels open into a recessed curved surface at a central portion thereof. A diaphragm seals the curved surface at the center of the body and is fixed in place by a load cell. The load cell has a movement amplifying device and indicator mounted thereon. The movement amplifying device rests on the diaphragm, connects to the indicator and is fixed in place by the load cell. The opening holes of the two channels are elliptical in profile and machined so as to avoid any retention zones.

Abstract: The invention relates to a level detecting system for a powder container of a powder-coating apparatus. It contains an inductive proximity sensor (22) and an electrically insulating membrane (28) which is displaceable to-and-fro the proximity sensor and which is fitted on its inside surface opposite the proximity sensor with a metallic element (32) affixed to it and affecting the magnetic properties of the proximity sensor. The level detecting system operates regardless of any powder particles adhering to it.

Abstract: A differential pressure pickup with a small hysteresis volume which has a sensor element, two pressure measuring chambers adjacent thereto, two pressure receiving chambers closed off by separating diaphragms and two overload chambers separated from each other by an overload diaphragm, in which pickup the overload diaphragm has a closed outer edge and a closed inner edge and is firmly restrained along its outer edge and its inner edge.

Abstract: A gauge or differential pressure sensor has a base portion having walls which define a cavity within the base portion and a diaphragm portion positioned over the cavity. The base portion comprises silicon; the diaphragm portion comprises silicon; the substrate has a passageway from a surface of the substrate into the chamber; the walls of the cavity form an angle with the diaphragm of no more than ninety degrees; and the chamber has a depth of at least about 5 microns. Preferably, the pressure sensor has a lip within the passageway which prevents an adhesive used to glue the sensor to a base from flowing to the diaphragm and fouling it. The pressure sensor is made by forming a cavity in a first wafer, fusion bonding a second wafer over the first wafer in an oxidizing environment, and using the thin oxide formed when fusion bonding the wafers as an etch stop when opening the cavity to the atmosphere. Etch conditions are selected to form the preferred lip in the passageway.

Abstract: A non-contaminating pressure transducer module having an isolation member is disclosed. The isolation member isolates a pressure sensor within the transducer module from exposure to fluids flowing through a conduit in the module. The transducer module may be positioned in-line within a fluid flow circuit carrying corrosive materials, wherein the pressure transducer module produces a control signal proportional to either a gauge pressure or an absolute pressure of the fluid flow circuit. The pressure transducer module of the present invention also avoids the introduction of particulate, unwanted ions, or vapors into the flow circuit.

Abstract: A non-contaminating pressure transducer module having an isolation member is disclosed. The isolation member isolates a pressure sensor within the transducer module from exposure to ultra high purity fluids flowing through a conduit in the module without significantly affecting the accuracy of the pressure measurement. The transducer module may be positioned within a fluid flow circuit carrying corrosive materials, wherein the pressure transducer module produces a control signal proportional to either a gauge pressure or an absolute pressure of the fluid flow circuit. The pressure transducer module of the present invention also avoids the introduction of particulate, unwanted ions, or vapors into the flow circuit.