Abstract: A pipe having a pipe element for conveying a medium in a flow direction and having a flange element for connecting the pipe element to a connection partner. The pipe element has a pipe body with a media passage opening for conveying the medium in the flow direction. The flange element has a flange body with a media passage opening for conveying the medium in the flow direction. The flange element is arranged at one end of the pipe element in such a way that the media passage openings at least substantially overlap. The pipe has a sensor element which is arranged in the flange body in such a way that at least a portion of the sensor element can be in contact with the medium.

Abstract: An assembly includes a first enclosed flexible pressure chamber. A first extension arm extends from a first endwall of the first enclosed flexible pressure chamber. A second enclosed flexible pressure chamber includes a second extension arm extending from a second endwall of the second enclosed flexible pressure chamber. A lever arm is disposed on a pivot. A first end of the lever arm is attached to the first extension arm and a second end of the lever arm is attached to the second extension arm. A variable restriction element is connected to the second end of the lever arm.

Abstract: A device for controlling fluid flow pressure and flow rate is disclosed. The device includes a first orifice plate, a second orifice plate housed in a tubular structure. The first orifice plate includes a first orifice of a first diameter (d1) and the first orifice is positioned near an edge of the first orifice plate. The second orifice plate includes a second orifice of a second diameter (d2) and the second orifice is positioned near an edge of the second orifice plate. The tubular structure has an effective diameter (D) comprising the first orifice plate and the second orifice plate placed at perpendicular direction to the fluid flow within the tubular structure, separated by an optimum distance (X).

Abstract: A device for damping pressure pulses, in particular in a pressure sensor. The pressure sensor includes a housing. A damping insert, on whose peripheral surface runs a damping channel, is located in the pressure channel of the housing.

Abstract: A tunable pressure transducer assembly that comprises a sensing element disposed within a housing, wherein the sensing element is adapted to output a signal substantially indicative of an applied pressure, and a filter assembly also disposed within the housing. In one example embodiment, a method includes receiving, at a filter assembly having a tube, a cap and a cavity defined by a housing, a pressure, wherein the cap is positioned to set a predetermined volume of the cavity and the tube is associated with an application of the pressure to the cavity, wherein the pressure includes a static pressure component and a dynamic pressure component; filtering, by the tube and the cavity, at least a portion of the dynamic pressure component of the pressure to obtain a filtered pressure; outputting, from the filter assembly, the filtered pressure; and wherein the filtered pressure is used to determine the static pressure component of the pressure.

Abstract: A differential pressure transducer employing a coiled tube to eliminate varying pressure fluctuations is provided. In one embodiment, a method comprises receiving, at an inlet tube of a dampening chamber, a main pressure, wherein the main pressure includes a static pressure component and a dynamic pressure component; filtering, by the inlet tube, at least a portion of the dynamic pressure component of the main pressure; outputting, from the inlet tube, a first filtered main pressure; receiving, at a volume cavity of the dampening chamber, the first filtered main pressure, wherein the volume cavity is operatively coupled to the inlet tube; filtering, by the volume cavity, at least a portion of the dynamic pressure component of the first filtered main pressure; outputting, from the volume cavity, a second filtered main pressure; and wherein the dampening chamber is tuned to a predetermined resonance frequency.

Abstract: A fluid pressure spike attenuation device and a method of attenuating a fluid pressure spike are provided. A fluid channel extends through an inlet body from a first open end to a second open end. The inlet body can be connected to a fluid pressure source and receive a fluid from the fluid pressure source. The fluid channel has an increased cross-sectional area to attenuate a fluid pressure spike entering the fluid channel at the first open end. A sensing element is in fluid communication with the second open end. The sensing element senses a property of the fluid in the fluid channel. The method includes providing an inlet body defining a fluid channel. The method also includes attenuating a fluid pressure spike by dissipating a pressure wave as it moves through the increased cross-sectional area of the fluid channel.

Abstract: The present invention relates to a measuring device having a pressure sensor, with the pressure sensor having a measuring cell designed to detect a pressure. It is provided that the measuring cell of the pressure sensor is arranged in or adjacent to a protective cell filled with a measuring fluid that can be coupled to a fluid to be measured via at least one separating membrane. It is furthermore provided that a damping device is arranged in the protective cell between the separating membrane and the measuring cell, said damping device including a restrictor and a downstream volume expansion means that provides an increased volume between the restrictor and the measuring cell in the event of a pressure increase in the measuring fluid.

Abstract: A piezoresistive pressure sensor that uses a protective gel to protect the piezoresistive device is susceptible to lead wire failure by vibration-induced waves in the protective gel. Such waves can be reduced and the device made more robust by the use of three-dimensional structures in the gel, which are configured to reduce and/or re-direct vibration-induced pressure waves in the gel. The structures are referred to as “breakwaters” in that they protect lead wires and lead wire connections from wave fronts and the damage that wave-induced pressure on the lead wires causes.

Abstract: A compressor unit is particularly suitable for compressing air in portable and/or transportable devices. The compressor unit includes a motor, a compressor, and a pressure gauge (manometer). The pressure gauge is connected to the compressor unit through a threaded connection and the supply of the pressure medium to the pressure gauge travels through the threads.

Abstract: A pressure sensor is arranged on a supply/discharge pipe of a reactive gas to be supplied to or discharged from a fuel cell, and measures the pressure of the reactive gas in the pipe. The pressure sensor is provided with an engaging section which has a screw and engages with a pipe wall of the pipe; a pressure detecting section, which faces a reactive gas channel of the pipe and detects the pressure inside the pipe by displacement; a displacement sensor, which is arranged in the pressure detecting sensor and measures displacement of the pressure detecting section; and a buffer section, which connects the engaging section with the pressure detecting section by sandwiching a buffer layer which communicates with the reactive gas channel of the pipe, and eliminates abnormal displacement of the pressure detecting section by deforming to a stress generated by torque of the screw, at the time when the pressure sensor is engaged with the pipe.

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

Abstract: A pressure detector for detecting a high side pressure from a high pressure side impulse line and a low side pressure from a low pressure side impulse line includes a high side pressure variance calculating section for calculating a high side pressure variance from a high side pressure fluctuation calculated from a high side pressure signal, a low side pressure variance calculating section for calculating a low side pressure variance from a low side pressure fluctuation calculated from a low side pressure signal, a rate calculating section for calculating a variable according to a ratio of the high side pressure variance to the low side pressure variance, and a determining section for determining blockage of the high pressure side impulse line or blockage of the low pressure side impulse line based on a value of the variable.

Abstract: A relative pressure sensor comprises two chambers and two separating membranes respectively provided for a process pressure and an ambient pressure. The chambers are separated by a pressure-sensitive element and are filled with a transmission medium. In order to attenuate process-side overload pulses, which act upon the first separating membrane, a hydraulic damper is provided that is placed on the side of the atmosphere between the second separating membrane and the pressure-sensitive element. The pressure-sensitive element is a piezoresistive silicon chip, the transmission medium consists of silicone oil, and the damper is comprised of a filter element made of sintered bronze having 29% porosity and an 11 micrometer pore diameter. The filter element has a length of 8 mm and a diameter of 2 mm.

Abstract: An apparatus and method for pressure sensing includes a Bourdon tube connected to a source of fluid pressure for sensing pressure changes therein, the Bourdon tube containing a pressure sensitive medium, a socket having a bore therethrough and positioned to fluidly connect the Bourdon tube with the source of pressure, a diaphragm positioned in the bore between the Bourdon tube and the source of pressure so as to isolate the pressure sensitive medium from the fluid whose pressure is sensed, and a dampener positioned between the diaphragm and the Bourdon tube, the dampener having a porous metallic body effective for substantially dampening transmission of a pressure pulse from the source of pressure to the pressure sensitive medium.

Abstract: An apparatus and method for pressure sensing comprises a Bourdon tube connected to a source of fluid pressure for sensing pressure changes therein, the Bourdon tube containing a pressure sensitive medium, a socket having a bore therethrough and positioned to fluidly connect the Bourdon tube with the source of pressure, a diaphragm positioned in the bore between the Bourdon tube and the source of pressure so as to isolate the pressure sensitive medium from the fluid whose pressure is sensed, and a dampener positioned between the diaphragm and the Bourdon tube, the dampener having a porous metallic body effective for substantially dampening transmission of a pressure pulse from the source of pressure to the pressure sensitive medium.

Abstract: A probe for measuring pressure oscillations includes an inner tube functioning as a measuring tube, an outer tube positioned so as to envelop the measuring tube, a toroidal space open to one side being defined between an outer wall of the measuring tube and an inner wall of the outer tube, a pressure transmitter, which is in connection with the interior of the measuring tube in the area of a transmitter end of the measuring tube, and a semi-infinite tube, which is connected at a first end to the transmitter end of the measuring tube, and which is connected at a second end to the toroidal space. The semi-infinite tube is constructed as a winding positioned around at least one of the measuring tube and the outer tube, thereby providing a compact and robust construction of a probe module, which is suitable especially for continuous use in the measuring of combustor pulsations in gas turbines.

Abstract: A high-pressure sensor specially for monitoring pulsating hydraulic pressure impulses, as for example in injection systems of combustion engines is provided with a pressure space shaped balloon-like before the diaphragm part, enabling optimal measuring signals to be combined simultaneously with significantly reduced mechanical forces in the welded joint. In addition, welding techniques are proposed enabling a gapless internal welding zone to be achieved, so that notch effects and migratory cracks resulting from these and leading to fractures are obviated. As optimal connection between measuring head and threaded body a two-stage welding routine is proposed first an internal weld is performed by electrical upset welding and then external welding by electron beam, inert gas or laser welding.

Abstract: In a pressure-measuring device (10) for measuring pressure fluctuations in a space (15) which is filled with hot gases at a first temperature (T1) and is delimited by at least one wall (12, 14) from an outer space (28) which is at a lower second temperature (T3), in particular for measuring pressure fluctuations in the combustion chamber (15) of a gas turbine (11), a measuring tube (16) largely free of end reflections with regard to the pressure fluctuations is passed from the space (15) through the at least one wall (12, 14) into the outer space (28), and, in the outer space (28) behind the at least one wall (12, 14), a pressure sensor (18) for sensing the pressure fluctuations is connected to the measuring tube (16, 21, 23).

Abstract: A pressure difference detector for detecting a pressure difference between atmospheric pressure and a fuel system vapor pressure to be measured, includes a pressure dampening member 17a for dampening the flow of atmospheric air between an introducing inlet 11a and a reference pressure chamber 12 to limit the air flow rate to a value smaller than a leakage flow rate between the chamber and a fuel system vapor pressure introducing inlet 11b due to a leaking 0 ring seal. This prevents an erroneous judgment that the fuel system is leaking.

Abstract: A fuel injection and control system for a V-type, two cycle, crankcase compression, internal combustion engine. The fuel injection system includes fuel injectors positioned in the valley of the engine and which are supplied with fuel under pressure from a fuel tank through a line in which a fuel filter and fuel pump are positioned. The fuel pump and fuel filter are disposed at one end of the engine and the amount of pressure supplied to the fuel injectors is controlled by a pressure regulator that regulates pressure by bypassing excess fuel back to the fuel filter upstream of the filter element. A throttle control and throttle position sensor are disposed at the opposite end of the engine and exhaust control valves are provided outside of the valley of the "V" of the engine.

Abstract: A pressure transducer is shown having a pressure responsive movable diaphragm which effectively forms a wall of a pressure chamber; the diaphragm upon sensing fluid pressure thereagainst is effective for accordingly varying an electrical resistance; a passage operatively interconnects the pressure chamber with a source of fluid whereby the fluid and its pressure are communicated to the pressure chamber; the passage is shown as being helically formed in order to, within a limited axial length about which the helical passage is formed, sufficiently damp perturbations in the pressure of the fluid.

Abstract: A pressure/control gage (12) includes a housing (4) defining an elongate, generally funnel shaped fluid chamber (6) having an open end (8) at the base of the fluid chamber. The open end is sealed by a diaphragm (10). The sealed fluid chamber includes a liquid (26), such as mercury, and a gas (28) defining an interface (30) between the two. The liquid is positioned against the inner surface (20) of the diaphragm. The outer surface (22) of the diaphragm is coupled to a source of pressure (18). The location of the interface changes according to the pressure applied to the outer surface of the diaphragm. Preferably the housing is clear, so the interface can be visually observed, with visual markings (32, 34) indicating the pressure. Also disclosed is a novel surge control valve (40) in which a resilient material (42) is positioned transversely across the fluid passageway (24) connecting the pressure source and the diaphragm.

Abstract: A control console for a gas die cylinder system which includes a plurality of gas die cylinders to which gas under pressure is provided wherein the control console comprises a body including an inlet for gas, a pressure chamber communicating with said inlet, a visual pressure gauge of the direct pressure type communicating with the chamber. An outlet extends from the chamber to the exterior of the body and a one way pressure control valve is provided between the outlet and the chamber and operable upon predetermined pressure in the outlet to modulate and maintain the pressure in the chamber at a predetermined pressure thereby minimizing oscillations and vibrations in the direct type pressure gauge.

Abstract: A flow restricting device is described which includes a conduit with a flow inhibitor therein. A plug stem is placed inside a passage in the inhibitor such that it can slide axially, while the head of the plug, which has a larger cross-sectional area than the passage, remains outside the passage. When the fluid pressure upstream of the flow inhibitor is greater than the fluid pressure downstream thereof, the head of the plug is forced against the face of the inhibitor and flow is restricted. To facilitate resetting of the inhibitor, the head allows a small amount of flow to pass to the downstream side, thereby equalizing the pressure across the device.

Abstract: This disclosure sets forth a fluid flow line which extends at one end from a fluid source at a pressure to be measured comprised of fluids contained within a well borehole, and the fluid flow line has a "J" shaped component to trap debris and trash to prevent it from flowing the full length of the fluid flow line and contacting a pressure transducer. The flow line is further defined by the threaded connection of two structural components making up the sonde wherein the components thread together and threads are sufficiently spaced apart to form an elongate helix as part of the flow path.

Abstract: A pressure transducer is shown having a pressure responsive movable diaphragm which effectively forms a wall of a pressure chamber; the diaphragm upon sensing fluid pressure thereagainst is effective for accordingly varying an electrical resistance; a passage operatively interconnects the pressure chamber with a source of fluid whereby the fluid and its pressure are communicated to the pressure chamber; the passage is shown as being helically formed in order to, within a limited axial length about which the helical passage is formed, sufficiently damp perturbations in the pressure of the fluid.

Abstract: An improvement to a flow control system is disclosed which comprises a transducer apparatus having dampening means to prevent or reduce the destructive effect of water hammers in such fluid control systems. This is especially useful in surgical irrigation and aspiration systems. The dampening means functions by diverting the transient fluid waves away from the delicate pressure-sensing means until a portion of the kinetic energy contained therein is dispersed.

Abstract: The waveform of a blood pressure of a patient is corrected by a pressure correcting mechanism having an air chamber having a volume ranging from 1 to 150 .mu.l and a resistance passage having one end communicating with the air chamber and the other end with a blood pressure measuring line. The resistance passage has a cross-sectional area ranging from 2000 to 160,000 .mu.m.sup.2 and a length ranging from 0.5 to 40 mm. A fluid such as a physiological saline solution filled in the blood pressure measuring line can flow through the resistance passage into the air chamber to dampen an extraneous pressure wave transmitted through the blood pressure measuring line.

Abstract: A lubricating system for an internal combustion engine including a separate lubricating pump that operates with cyclically operating pressure. Detecting means are incorporated for damping the output pressure of the pump and sensing the damped pressure to insure adequate operation of the system.

Abstract: A drilling fluid saver valve apparatus incorporating a pressure test device. The apparatus includes a tubular body having a valve seat and a closure check valve moveably mounted in spring loaded relation within the body to be normally seated in closed relation to permit flow of fluids under pressure only from a drilling kelly into the drillpipe, and a pressure test device connected into a side port formed in the body between the valve seat and drillpipe.

Abstract: A damping device for use in conjunction with a circulatory pressure measuring system to attenuate resonant pressure waves therein includes a series connector for connection to the pressure measuring system. An integrally connected parallel portion includes a capillary tube fluid resistance element in communication with the series connector. A flexible membrane isolates the capillary tube from a fixed volume gas chamber located adjacent the flexible membrane.

Abstract: An ink jet printing device including a printing head having a nozzle through which ink can be ejected. The head includes an internal chamber ink and ink ejection is caused by internal pressure pulses. The internal chamber is formed in part by a deformable diaphragm which prevents extreme ambient temperature variations from causing damaging liquid pressure fluctuations.

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

Abstract: A differential pressure transmitter has a body wherein a pressure transmission passage filled with a pressure transmission medium is formed. A differential-pressure/displacement converting element is disposed in the body to partition the passage into a high-pressure side section and a low-pressure side section. A first seal port through which the transmission medium is charged into the high-pressure side section and a second seal port through which the transmission medium is charged into the low-pressure side section are formed in the body. First and second throttle members capable of being taken out through the seal ports are disposed in the high- and low-pressure side sections to throttle the sections.

Abstract: A low oil pressure sensor (32) is provided for direct mounting to a lubrication pump (4) for direct sensing of differential pump pressure. An internal sensor body portion (40) is exposed to the internal pump environment and has a magnetically permeable piston (48) axially slideable therein. High and low pressure aperture ports (56 and 50) through the internal sensor body sidewalls communicate respective high and low pressure sides of the pump to respective axial ends (58 and 54) of the piston. A radial gap (60) between the piston (48) and the interior sidewall (62) of the internal body portion provides a long narrow axial damping passage for damping high pressure pulses and transients from the high pressure side of the pump, to prevent false triggering. A magnetic coil (66) in the body detects piston movement according to changed flux linkage.

Abstract: An improved differential pressure transducer is provided having static overpressure protection means. The overpressure protection means includes spring-loaded element being shiftable in response to an overpressure condition.

Abstract: A ruggedized depth transducer for measuring ambient hydrostatic pressure adjacent an acoustic source wherein the transducer includes a housing having a depth sensor mounted therein. The housing further includes a bore for placing the depth sensor in fluid communication with the ambient pressure. Mounted within the housing bore are a series of mechanical filters for attenuating high-intensity pressure spikes generated by the acoustic source from damaging the depth sensor contained within the housing. The mechanical filters allow gradual changes in ambient pressure to pass into the bore and influence the depth sensor.

Abstract: A weight carrier rests on a floating ceramic ball supported within a nozzle by flow-regulated air. The air flows in an inlet path within the nozzle to support the ball and then exits through an outlet path downstream of the ball. A pressure regulator maintain a selected pressure in correspondence with a given weight on the ball. Dampening is provided in the nozzle itself rather than in a canister external thereto. Helical input and output paths wind around the axis of the nozzle to and from the ball. The cross section of the exit path increases with distance from the ball. The path may comprise an thread of increasing depth in an adjustment screw received in a cylindrical bore along the axis of the nozzle.

Abstract: A pressure dome in which the wall forming the cavity containing fluid under a pressure that is to be measured has such a low compliance as to prevent expansion or contraction of the base of the dome resulting from changes in its temperature from causing the diaphragm of a transducer coupled thereto from buckling.

Abstract: Apparatus for removing undesirable resonance in a closed, tubular fluid flow system permitting more accurate transducer measurement of varying fluid pressure within the system is disclosed. The apparatus includes a compliant air cavity coupled to the system via a small diameter aperture, or passage. The cavity is within an elongated pipe, or tube, the proximal end of which is inserted in a conventional cylindrical sleeve and includes the small diameter passage for coupling the air cavity to the fluid system. A plurality of such elogated tubes, each having a predetermined length and thus a predetermined cavity size, are provided for selective insertion in the cylindrical sleeve for providing the fluid flow system with a fixed series hydraulic resistance and an incrementally variable parallel hydraulic capacitance for matching the hydraulic impedance of the system.

Abstract: A hydraulic accumulator unit having a volume variable against the force of a spring and a restrictor are provided for eliminating slow pressure fluctuations in a measuring instrument responsive to fluid pressure, through which restrictor the hydraulic accumulator unit is connected to the fluid subjected to the pressure fluctuations. The measuring instrument measures the pressure in the accumulator unit.

Abstract: A method of sensing a knocking taking place in an internal combustion engine through the sensing of pulsative component of the cooling water pressure or lubricating oil pressure. The sensing of the pulsative component is made by removing the static component from the composite pressure which is the sum of the pulsative component and the static component. An apparatus for sensing a knocking taking place in an internal combustion engine has a differential pressure sensing mechanism including a pressure sensing diaphragm and a pulsation absorption mechanism. The pressure sensing diaphragm receives at its one side the composite cooling water pressure or composite lubricating oil pressure which is the sum of the pulsative component and static component. The pulsation absorption mechanism absorbs the pulsative component from the composite pressure so as to transmit only the static component of the pressure to the other side of the pressure sensing diaphragm.

Abstract: A generally cylindrical plug is adapted for a snug fit in a socket bore communicating with the inlet of a pressure gauge. The plug includes an upstream portion and an axially contiguous downstream portion, each cooperating with the surrounding surface of the socket bore to define a continuous flow path communicating inward to the sensing unit of the gauge. Through the upstream portion, the flow path is annular in cross-section between the plug surface and the bore surface while the downstream portion defines a helical flow path communicating with the open bore downstream thereof. Dimensionally critical in the relationship of the flow path defined in the upstream portion, versus the flow path defined in the downstream portion is the requirement that the former have a clearance dimension relatively smaller than the minimum clearance dimension through the cross-section of the latter.

Abstract: The subject matter of the invention is an impeller flow-meter, particularly for accurate measurement of the flow rate of liquid fuel fed to an internal-combustion engine.In the flow-meter according to the invention, an impeller chamber (1) is provided with an inlet pipe (2), surrounded coaxially by an ante-chamber (3). A supply pipe (4) is provided for the liquid fuel and an offtake pipe for excess fuel, these pipes being situated in different planes along the axis of ante-chamber (3). A space (6) is located between the entrance end of inlet pipe (2) and the exit end of supply pipe (4). A slot (7) is formed between the outer wall of inlet pipe (2) and the inner wall of the coaxial ante-chamber (3). The slot (7) communicates with space (6) and offtake pipe (5). As a result of this structure, pulsations in the liquid supply, which would affect the impeller accuracy, are substantially extinguished in space (6) before reaching the impeller chamber (1).

Abstract: A novel apparatus and method for suppressing unwanted resonance in an electromanometry system. The apparatus includes a compliant air cavity connected through a variable impedance device which is coupled in parallel to the liquid-filled catheter of the electromanometry system. By varying the hydraulic impedance through which the compliant air cavity is coupled to the system, precise impedance matching capability is provided over a wide range of hydraulic impedance values, thereby permitting suppression of unwanted resonance and improved frequency response of recorded waveforms in a wide variety of catheter-transducer systems.

Abstract: A device for measuring pore water pressure in soils employs a pore pressure sound (2) as a sensing member and a closed measuring system (5,6) for creating the least possible disturbance in soils having a low degree of permeability, such as clay. The closed liquid-filled measuring system comprises a hypodermic needle type (20) of connection between the pore pressure sound and a measuring device (3), said needle being operative to penetrate a member of resilient material to extend into a liquid-filled chamber in said pore pressure sound and transfer a reading of the pore water pressure to said measuring device.

Abstract: A pulsation dampener providing high attenuation in a narrow quiet band or frequency. The pulsation dampener is tuned to provide a reflected wave 180.degree. out of phase in the narrow band to cancel the undesired pulsation. A silicone polymer contained by a diaphragm is used as the dampening fluid. The pulsation dampener operation is virtually unaffected by changes in working fluid pressure or density. The latter aspect makes the pulsation dampener particularly well suited for use in well drilling operations where pressure pulses in the drilling fluid are used to transmit information to the surface.

Abstract: A pressure indicating device according to the present invention includes a diaphragm assembly engaging one extremity of an indicator actuating means whereby flexing of the diaphragm caused by fluid pressure or other force will induce movement of the indicator actuating means. Movement of an indicator in relation to a fixed delineated face caused by movement of the indicator actuating mechanism results in a visual representation of reading bearing some predetermined relationship to the pressure causing the flexing of the diaphragm.

Abstract: A directional device operating similar to a wind vane has a hollow vertical shaft which is journalled in a housing containing three chambers in communication. An air inlet port is located on the side of the directional vane and communicates through the hollow journalled shaft into the first chamber. A small aperture in the wall between the first and second chambers dampens the movement of the fluid flow from chamber 1 to chamber 2. A conventional baffle separates the second and third chambers and simultaneously allows fluid flow from the second to the third chamber while further damping the fluid flow to such a point that the fluid in the third chamber is substantially static. The third chamber is in communication with a differential pressure gauge which then compares the static pressure in chamber 3 with another pressure source.