Abstract: An apparatus for measuring differential pressure includes first and second sensor units. The first sensor unit detects directly a first pressure of a substance at a first position and acquires a first detection result that indicates the first pressure. The second sensor unit detects directly a second pressure of the substance at a second position different from the first position. The second sensor unit acquires a second detection result that indicates the second pressure and receives the first detection result from the first sensor unit. The second sensor unit calculates a differential pressure between the first and second positions with reference to the first and second detection results.

Abstract: A measuring apparatus includes at least one microsensor having at least two chambers filled with a gas. The chambers are connected to one another by at least one channel. Moreover, the chambers are sealed off to the outside in a gastight manner. Also provided is a detection device for detecting a gas stream flowing in the channel, which gas stream arises on account of different pressures prevailing in the chambers. The invention also relates to a method for producing the microsensor according to the invention.

Abstract: A manometer integrated into a manual resuscitator includes a housing with a communication path, and a pressure gauge integrally forming part of the housing. A sensing chamber and an atmospheric chamber are separated by a diaphragm subject to distortion by differential pressure between the chambers, with a spring to restore the diaphragm upon equalization of the pressures. A shaft journaled in a first bearing on the diaphragm and a second bearing in one of the chambers rotates in the bearings upon diaphragm distortion, and an indicator on the shaft indicates differences in pressure between the chambers.

Abstract: A method for measuring average velocity pressure of a stack comprises the following steps. First, a total pressure measuring device is provided. The total pressure measuring device then measures the total pressure at a first location in the stack. Next, physical parameters comprising a distance between the first location and an outlet of the stack, a diameter and shape thereof are obtained. A formula of a static pressure and the average velocity pressure between the outlet and the first location is obtained by comparing the physical parameters to known fluid mechanics data. Finally, the average velocity pressure is obtained from the formula and the total pressure.

Abstract: A probe 10,170 is provided that measures the speed of sound and/or vortical disturbances propagating in a single phase fluid flow and/or multiphase mixture to determine parameters, such as mixture quality, particle size, vapor/mass ratio, liquid/vapor ratio, mass flow rate, enthalpy and volumetric flow rate of the flow in a pipe or unconfined space, for example, using acoustic and/or dynamic pressures. The probe includes a spatial array of unsteady pressure sensors 15-18 placed at predetermined axial locations x1-xN disposed axially along a tube 14. For measuring at least one parameter of a saturated vapor/liquid mixture 12, such as steam, flowing in the tube 14. The pressure sensors 15-18 provide acoustic pressure signals P1(t)-PN(t) to a signal processing unit 30 which determines the speed of sound amix propagating through of the saturated vapor/liquid mixture 12 in the tube 14 using acoustic spatial array signal processing techniques.

Abstract: Reliability and accuracy in a pressure measurement transmitter are provided by employing a plurality of absolute or gauge pressure sensors operating in conjunction with a differential pressure sensor. A method is also provided to perform diagnostics based upon the readings of the three pressure sensors. Further, should one of the three pressure sensors fail, a reasonable estimate of process pressure being measured by the failed sensor can be generated based upon the remaining two sensors.

Abstract: A pressure sensor has a case having a first side and a second side, and a sensing portion mounted to the case. A first diaphragm is disposed on the first side of the case such that a first chamber is defined. A second diaphragm is disposed on the second side of the case such that a second chamber is defined. The first chamber and the second chamber are filled with a pressure medium such as an oil. The case forms an introduction passage for introducing the pressure medium into the first chamber and the second chamber. In a condition that the first chamber and the second chamber are filled with the pressure medium, the introduction passage is sealed by a sealing part so that the first chamber and the second chamber are separated from each other and from an outside of the case.

Abstract: A differential pressure indicator and method of configuring a differential pressure indicator is provided. The differential pressure indicator is configurable to provide open circuit or closed circuit logic and includes a housing, a pressure responsive element, a post, first, second and third electrical contacts and an electrical insulator from an insulative material. The electrical insulator separates the third electrical contact from either the first contact or the second contact to provide a desired type of logic. The differential pressure indicator may use substantially similar components to provide either open circuit or closed circuit logic or the components may be rearranged to provide either open circuit or closed circuit logic.

Abstract: The invention relates to a device and a method for the status monitoring of a pressure measuring unit in an absolute or differential or relative pressure transducer, a pressure-sensitive element installed in the pressure measuring unit being impinged with at least one pressure generated by at least one membrane. During a defined diagnosis time interval, a testing element integrated in the pressure measuring unit is induced to undergo a change in volume, preferably by electrical activation. The pressure difference caused as a result in the pressure measuring unit is registered by a pressure-sensitive element. The curve registered during a diagnosis time interval is compared with a reference curve recorded with the pressure measuring unit intact. A fault indication is given if the deviations between the registered curve and the reference curve exceed predetermined tolerance values.

Abstract: An inflatable air cell pressure transducer. The air cell has a concavity formed therein. The concavity has two edges, wherein increased pressure within the air cell causes contraction of the concavity moving the two edges closer.

Abstract: A pressure pickup probe assembly includes a probe housing, a plurality of openings, and a pickup probe. The probe housing is configured to be mounted within, and extend at least substantially across, a flow passage. The probe housing further includes at least an inner surface and an outer surface. The probe housing inner surface defines at least a plenum therein. The plurality of openings is formed in the probe housing, and each opening extends between the probe housing inner and outer surfaces and is in fluid communication with the probe housing plenum. The pickup probe is disposed at least partially within the probe housing, and has at least a first end, a second end, and a bore extending between the first and second ends and that is in fluid communication with the probe housing plenum.

Abstract: A pressure pickup, having a pressure chamber, which is located between a separating membrane and a platform. A pressure canal for hydraulic transmission of pressure to a measuring cell, includes, for dynamic overload protection, a Venturi throttle implemented by providing that the pressure canal has at least one segment whose flow cross section is variable. Such segment is preferably provided in the form of an annular canal. The flow cross section can be changed, for example, by an axial shifting of a conical inner wall relative to a complementary, conical outer wall, or by the deforming of an elastic inner or outer wall of the annular canal.

Abstract: A dual gauge assembly. In an exemplary embodiment, the dual gauge assembly includes a housing. Further, a display face is disposed within the housing for displaying a pressure range. In addition, an indicating device is disposed within the housing for indicating pressure for at least two different pressure sources. Moreover, at least two ports are coupled to the housing for pneumatically coupling the at least two different pressure sources to the indicator assembly. The indicating device provides a visual indication of the at least two different pressure sources within the single housing.

Abstract: According to the present invention, there is provided a high-precision differential pressure sensor which is not affected by a considerable change in baseline pressure. A differential pressure sensor of the present invention includes: a pair of diaphragms, each including a diaphragm portion capable of being deformed due to application of a pressure and a support portion for holding an outer peripheral edge of the diaphragm portion; a pair of fixed electrodes in disk-like form fixed to the support portions of the diaphragms; and a movable electrode including a disk-like electrode portion and shaft-like projections extending in opposite directions from a central portion of the electrode portion. The shaft-like projections extend at a right angle relative to the electrode portion, and the movable electrode is secured to central portions of the diaphragms through the shaft-like projections so that the electrode portion faces each of the fixed electrodes in a predetermined spaced relationship.

Abstract: The ultra-precision micro-differential pressure measuring device comprises a device body 1 having an inner space part therein, a pressure receiving plate 3 which is installed inside the inner space of the device body 1 and divides the said inner space hermetically into a lower space 7 and an upper part space 8, an electronic weighing and pressure converting device 2 which is installed in the lower space 7, and supports and secures the pressure receiving plate 3, and a liquid sealing part R which liquid-seals the outer peripheral part of the aforementioned pressure receiving plate 3 and maintains the air-tightness between the lower space 7 and the upper space 8. A micro-differential pressure between a pressure P1 inside the upper space 8 and a pressure P2 inside the lower space 7 is measured by the electronic weighing and pressure converting device 2 through the pressure receiving plate 3.

Abstract: A fiber optic differential pressure sensor. In a described embodiment, a differential pressure sensor system for use in a subterranean well includes a fluid property sensing housing having a flow passage formed therethrough. A differential pressure sensor has an optical fiber extending in a wall having a first side and a second side, each of the first and second sides being exposed to pressure in the flow passage.

Abstract: A differential pressure detection type pressure sensor includes: a casing having a concavity; a pressure detection element disposed on a bottom of the concavity; a through hole; a first protection member in the concavity; and a second protection member in the through hole. The pressure detection element has one side facing the bottom of the concavity and the other side facing an opening of the concavity. The through hole includes one opening on the bottom of the concavity and the other opening on a part of the casing. The height of the first protection member facing the opening of the concavity and the height of the second protection member in the other opening of the through hole are on a same plane.

Abstract: A differential pressure transducer which incorporates a Fabry-Perot sensor for direct quantitative measurements of the distance displaced by a piston abutting two pressure boundaries is described. The apparatus includes a piston with an annular protrusion which is fitted into a transducer housing having a peripheral groove that serves as a stop to prevent damage to the in overpressure situations. A method of measuring differential pressure using a Fabry-Perot sensor is also contemplated.

Abstract: A dual gauge system determines pressures of two separately contained gases by use of two separate pointer—Bourdon tube sections within the dual gauge. The Bourdon tube of a first one of the sections is gaseously coupled to a first one of the contained gases to determine pressure of the first one of the contained gases and a Bourdon tube of a second one of the sections is gaseously coupled to a second one of the contained gases to determine pressure of the second one of the contained gases. Accuracy of pressure determination is enhanced by allowing for separate calibration of each of the two gauge sections.

Abstract: A pressure sensor (30) for sensing a fluid pressure in harsh environments such as the air pressure in a tire, by using a chamber (58) partially defined by a flexible membrane (50), the flexible membrane (50) is a laminate having at least two layers wherein at least one of the layers is at least partially formed from conductive material, and the chamber (58) containing a fluid at a reference pressure, such that the flexible membrane (50) deflects from any pressure difference between the reference pressure and the fluid pressure; and, associated circuitry (34) for converting deflection of the flexible membrane (50) into an output signal indicative of the fluid pressure. Forming the membrane from a number of separately deposited layers alleviates internal stress in the membrane (50). The layers can be different materials specifically selected to withstand harsh environments.

Abstract: A differential pressure sensor includes a measuring mechanism having a chamber on the high-pressure side that is sealed by a first dividing membrane, and a chamber 6 on the low-pressure side that is sealed by a second dividing membrane. The first dividing membrane is loadable with a pressure acting on the high-pressure side and the second dividing membrane with a pressure acting on the low-pressure side, and the chamber on the high-pressure side is separated from the chamber on the low-pressure side by a pressure-sensitive element, especially a measuring membrane, and the chambers of the high- and low-pressure sides are filled with a transfer medium. For damping of overload pulses acting on the first dividing membrane on the high-pressure side, a hydraulic throttle is provided, which is arranged on the low-pressure side between the second dividing membrane and the pressure-sensitive element.

Abstract: A pressure sensing device for measuring the pressure of a fluid, comprising: a measurement diaphragm which is at least partially made of semiconductor material, is provided with a first surface and a second surface which are exposed respectively to a first pressure and to a second pressure, and undergoes a deformation following the application of the first pressure and of the second pressure; and a resonant element made of semiconductor material which is provided with a first end portion and with a second end portion for mechanically coupling the resonant element to the measurement diaphragm, the oscillation frequency of the resonant element varying according to the deformation to which the measurement diaphragm is subjected; and first circuit means for generating a sensing signal which is indicative of the oscillation frequency of the resonant element.

Abstract: A pitot pressure sensing probe assembly is made up of individual components comprising a barrel formed with a longitudinal interior passageway and a conical end cap at its leading end. A strut that has stamped or formed sections secured together to form the strut with a compound curvature includes a neck that has a bore to receive a hub of the barrel. The end cap has a pitot port for sensing fluid pressure. The barrel includes a water trap at its leading end for trapping water and permitting it to drain through a hole in the conical end cap. The longitudinal internal passageyway carries the fluid pressure sensed by the pitot port to remote instruments. The individual components are easily formed and are secured together to make the pitot pressure sensing probe assembly.

Abstract: A pitot pressure sensing probe assembly is made up of individual components comprising a barrel formed with a longitudinal interior passageway and a conical end cap at its leading end. A strut that has stamped or formed sections secured together to form the strut with a compound curvature includes a neck that has a bore to receive a hub of the barrel. The end cap has a pitot port for sensing fluid pressure. The barrel includes a water trap at its leading end for trapping water and permitting it to drain through a hole in the conical end cap. The longitudinal internal passageyway carries the fluid pressure sensed by the pitot port to remote instruments. The individual components are easily formed and are secured together to make the pitot pressure sensing probe assembly.

Abstract: A probe 10,170 is provided that measures the speed of sound and/or vortical disturbances propagating in a single phase fluid flow and/or multiphase mixture to determine parameters, such as mixture quality, particle size, vapor/mass ratio, liquid/vapor ratio, mass flow rate, enthalpy and volumetric flow rate of the flow in a pipe or unconfined space, for example, using acoustic and/or dynamic pressures. The probe includes a spatial array of unsteady pressure sensors 15-18 placed at predetermined axial locations x1-xN disposed axially along a tube 14.for measuring at least one parameter of a saturated vapor/liquid mixture 12, such as steam, flowing in the tube 14. The pressure sensors 15-18 provide acoustic pressure signals P1(t)-PN(t) to a signal processing unit 30 which determines the speed of sound amix propagating through of the saturated vapor/liquid mixture 12 in the tube 14 using acoustic spatial array signal processing techniques.

Abstract: A differential static pressure measuring or activating device measuring fluid flow through a duct including two pitot tubes each including a proximal end connected to a valve, a distal end portion located in the duct extending generally parallel to each other and perpendicular to the air flow through the duct having open distal ends and a plate located between the distal end portions of the tubes creating a differential static pressure between the open ends of the tubes. The open distal ends of the tubes incline toward the plate such that the open ends face toward and away from the direction of the gas flow through the duct.

Abstract: Regulator for precision control of pressure based on a means of measuring pressure differentials. More specifically, the present invention provides a pressure control that tracks a relatively high background pressure, and applies a positive or negative offset to create the small pressure differentials that can be utilized to transport fluids within a capillary network. The present invention is also directed to a method of controlling microfluidic elements (such as donut cavities) with a high degree of precision. In high performance liquid chromatography applications, this is accomplished using tracking pressure regulators to measure and respond to the difference between the liquid pump pressure and the regulated pneumatic pressure.

Abstract: The dynamic stiffness of a flight control actuator is assessed by providing an actuator control system that includes an actuator and a portion of the actuator is coupled to an aircraft control surface. A command signal is applied to the actuator control system, which causes the production of a pressure differential across the actuator in response to the command signal that is based on the ability of the actuator to react to an inertial load generated by an acceleration of the aircraft control surface. A pressure signal representative of the pressure differential across the actuator is processed and the pressure signal is compared to known pressure differential values produced under similar conditions for specific actuator and specific control surface combinations.

Abstract: The present invention provides a stable differential pressure measurement system. Two micro-machined semiconductive capacitive sensors each has a diaphragm exposed on one side and having a sealed partially evacuated chamber within the sensor on the other side of the diaphragm. A circuit corrects the slope responses and offsets of the capacitive sensor output signals to provide an accurate differential pressure measurement. Sensitive electronics are buried within the sensors and isolated within the sealed housing to protect them from harsh surrounding media. Such harsh surrounding media can be found when the system is used in an automobile exhaust system.

Abstract: A method and device for void fraction measurement in a gas/liquid two-phase stratified flow system in disclosed. A couple of pressure-signal tubes are mounted to the through into the top and bottom walls of the horizontal pipeline portion of the flow system to measure the pressure differential value between the top and bottom interior position thereof. The height of liquid phase level of the stratified flow is calculated from the pressure differential value and the liquid-phase density. The void fraction is derived from the known geometric relation between the height of liquid-phase level and the cross section of the pipe. Each of the pressure-signal tubes is encased within a cylindrical cooling case to avoid flashing phenomenon from occurring within the pressure-signal tube. This method is applicable for the flow at steady or transient state under high temperature/pressure condition.

Abstract: A differential fluid pressure assembly (10) has an inner differential fluid pressure gauge (14) enclosed by an outer fluid-tight housing (12). A low pressure fluid inlet (34) is in fluid communication with the space (32) defined by the outer housing (12). A high pressure fluid inlet (38) extends through the outer housing (12) and is in fluid communication with a bourdon tube (44) within the differential pressure gauge (14). Low pressure fluid inlet (34) is connected to a low pressure line (36) extending to a low pressure fluid source. High pressure fluid inlet (38) is connected to a high pressure fluid line (40) extending to a high pressure fluid source for measurement of the differential fluid pressure between a low pressure source and a high pressure source.

Abstract: A differential pressure sensor comprises a pair of bourdon tubes disposed in an arrangement wherein deflections of the two bourdon tubes resulting from fluid pressures connected thereto take place in two opposite directions and the deflective extremities of the two bourdon tubes are linked to one another by a linkage, which linkage is coupled to a transducer that converts the displacement of the linkage to an electrical parameter such as the ohmic resistance, capacitance, reluctance, or resonance frequency as a measure of differential values between two pressures respectively connected to the two bourdon tubes.

Abstract: A position sensor includes a vibrating elongated member with a marker retained thereto in a sliding relationship thereon, wherein the marker coupled to a displacement of a target corresponding to a change of a physical quantity alters the natural frequency of the vibrating elongated member and, consequently, the numerical value of the physical quantity is determined from the natural frequency of the vibrating elongated member.

Abstract: A pressure transducer in the nature of a differential pressure transmitter including an instrument housing defining a chamber in which is mounted a sensing transducer one of several known types powered to provide a gauge signal that is to be supplied to instrumentation such as a controller or recorder, with the pressure sensing arrangement of the instrument being in the form of two oppositely coiled bourdon tubes mounted one on either side of the sensing transducer, with like ends of the tubes each mounting an output lever, which levers are respectively resiliently connected to the movable element of the transducer and in an oppositely acting manner, with the other ends of the respective tubes being separately connected to a mounting block arranged to provide for connection of the respective tubes to separate, externally located, sources of pressure fluids, and with one of the output levers being adjustable as to length for calibrating the instrument so that the action of the two tubes on the sensing transduc

Abstract: A digital differential pressure sensor with relatively low sensitivity to common mode line pressure errors. The sensor includes an airtight enclosure having a pair of pressure ports through which pressures are coupled to opposite sides of a pressure-sensing diaphragm, bellows, or Bourdon tube. The pressure-sensing elements generate torques which are transmitted by a shaft to stress-sensitive resonators which are isolated from the torque-producing elements by a sealed, flexible tube.

Abstract: A pressure gauge assembly for gauging and having an open-fronted casing connectable through check valving to one or more pressure lines, the valving being front-ported for receiving and normally held open by a plug inserted in each such port, the gauge of the assembly being so connected to the casing as to be removable therefrom only after removal of the one or more plugs and consequent closing of the check valving without either dismounting or uncoupling the casing from any pressure line.

Abstract: A pressure measuring device is provided with an indicator such as a bourdon tube (10) for indicating the absolute value of the difference in pressure between fluids applied to the indicator through first and second conduits (15) and (20). Valve means (25) including an element (100) actuable in response to the pressure in conduits (15) and (20) consistently applies the higher pressure fluid to that portion of the indicator adapted to receive such higher pressure fluid and the lower pressure fluid to that portion of the indicator adapted to receive the lower pressure fluid. Optical means such as transmitter (115) and receiver (120) are provided for indication of the sign (positive or negative) of the pressure difference.

Abstract: A precision metering device for very small quantities of fluids, in which a controlled deflection of one or more selected portions of a Bourdon tube are used to give precise metering of fluids in amounts of only a few microliters or less, and in which a single one of the precision metering devices may be used to provide selected variations of the small amounts of dispensed fluid and with different fluids, usually without extra purging procedures.

Abstract: A Bourdon tube apparatus is provided for monitoring the pressure of a fluid pressure source. The output of the Bourdon tube is translated into a curvilinear motion which is transmitted to a linearly movable actuator valve or indicator. To enhance the force output linear response or linear output of the Bourdon tube actuator, an abutment block is provided which contacts one or more turns of the Bourdon tube adjacent its closed end to prevent expansion movement of the Bourdon tube in a direction opposite to the desired linear output movement. The Bourdon tube is mounted for calibrational purposes by having its open end connected by a flexible pipe to a support post which is rotationally mounted for movement about its longitudinal axis and defines a fluid conduit connection between the pressure source being monitored and the open end of the Bourdon tube.

Abstract: An apparatus for protecting a pressure differential sensor from exceeding a maximum allowable pressure differential. The apparatus has a housing which has a low-pressure chamber and a high-pressure chamber. A pressure-sensitive member separates the high-pressure chamber and the low-pressure chamber from one another. A blocking member is provided for blocking the entrance of fluid into the high-pressure chamber in response to the pressure-sensitive member sensing an initial differential pressure between the high-pressure chamber and the low-pressure chamber which exceeds the maximum allowable differential pressure. There may also be provided equilibration structure for creating a hysteresis loop as to the magnitude of the pressure differential between the high-pressure chamber and the low-pressure chamber.

Abstract: A differential pressure gauge of the type comprising a controlling magnetic helix device carrying a pressure indicating pointer, the position of which is controlled by a magnet magnetically coupled to same and mounted on the free end of a helically coiled bourdon tube exposed to differential pressures within the gauge and anchored in the gauge housing at its other end for this purpose. The magnet has a planar pole face paralleling the axis of the helix and defines a magnetic axis that is normal to and intersects the helix axis. The gauge housing defines an integral one piece pressure wall that separates and physically seals the helix from the magnet and bourdon tube and defines within the gauge housing pressure cavity an operating space within which the magnet and its supporting bourdon tube are mounted and operate.

Abstract: Apparatus is disclosed for sensing fluid pressure by mechanical flexure of a tube according to the principles of the Bourdon tube, wherein the tube forms a part of the fluid flow path, and where the pressure may be sensed during both dynamic and static fluid flow conditions.

Abstract: Device for the continuous monitoring and remote indication of the prevailing operating condition of internal combustion engines serving preferably as a drive for motor vehicles based on the vacuum pressure occurring in the intake manifold, characterized by the combination of the following features: two Bourdon tubes are used as pressure measuring members, which Bourdon tubes are fastened each with one end rigidly on a common carrier, of which one Bourdon tube is completely closed and consequently is influenced only by outside air pressure, while the other Bourdon tube is connectable to the suction intake manifold of the internal combustion engine; arrangement of a carrier body for a number of contact elements at the free end of the Bourdon tube which is influenced by the outer air pressure, which contact elements by means of electrical lines are to be brought into connection with preferably optical indicator means such as different colored diodes and lamps, respectively; and arrangement of a carrier body for

Abstract: A pressure gauge assembly for aircraft tires and the like having a helical coil bourdon tube sensor capable of indicating a pressure differential between a monitored source of pressure and a calibrated reference source of pressure. The reference pressure is applied to one surface of the bourdon tube coils while the monitored pressure is applied to the other surface of the coils. The resultant movement is a linear indication of any pressure differential. A valve assembly can be provided with the pressure gauge assembly to permit fluidic access to the monitored pressure. If the volume of the monitored pressure is variable such as an aircraft tire, the secondary source of calibrated pressure can be provided with a predetermined pressure relative to the normal tire pressure to compensate for any volumetric changes in the tire during operation. In an alternative embodiment, the bourdon tube can be used to monitor the pressure in a fire extinguisher for indicating any leaks.

Abstract: Sensors, or transducers, which utilize elongated magnetically saturable tubes with sense lines that run through the tubes for simultaneous sensing of a plurality of parameters are disclosed. One version involves a single sensing element which has a first pair of diametrically disposed magnetic poles responsive to one condition that is positioned adjacent to one end of the tube and a second pair of diametrically disposed magnets responsive to another condition that is positioned adjacent to the other end of the tube. Another version involves two elements which have temperature vs. inductance characteristics which intersect, and a pair of diametrically disposed magnets responsive to another condition positioned adjacent the two elements.