Abstract: A system for monitoring the condition of impulse lines to a differential pressure sensor. The lines may be connected at two locations of a pressure source, such as a pipe having a fluid flow. One line may direct a pressure of the source to one side of a piezoelectric diaphragm and another line may direct another pressure to the other side of the piezoelectric diaphragm. The diaphragm may provide an electrical indication of the differential pressure between both sides of the diaphragm. One of the lines may also be connected to a piezoelectric diaphragm of a static pressure sensor. The latter diaphragm may provide an electrical indication of static pressure. Detection and comparison of noise levels of the electrical indications of the pressures may indicate if one or both lines are plugged, and which one if not both.

Abstract: A flowmeter detector for determining the flow volume of a fluid medium that includes a measuring line having first and second ends and a fluid medium entry and exit ports adjacent the fist and second ends and fluid medium flowing between the entry and exit ports is disclosed. An acoustic transducer is located at each end of the measuring line and each acoustic transducer has an overall dimension less than the cross-section diameter of the measuring line. The acoustic transducers are first operated to simultaneously transmit pulsed acoustic energy into the measuring line. The transducers are subsequently operated to receive the acoustic energy propagated through the measuring line. The flow volume is determined by evaluating the difference in the travel times of the pulsed acoustic energy propagated through the measuring line.

Abstract: A method and control system that monitors the high frequency or commonly referred to as the “noise” component of a measurement signal to detect plugging conditions in fluid flow systems monitored by DP-cell based sensors. This high frequency component has contributions from the process factors like disturbances, user actions and random effects like turbulence. A test statistic &thgr;(t) has been developed that monitors the proportion of variance introduced by the first two factors and the third factor. By monitoring this proportion, it is possible to detect a frozen sensor that is characterized by a dramatic reduction in the variance due to process factors over a sufficiently long detection window. The method and control system uses random sampling intervals to improve data quality. The sampling rate is also reduced by taking samples at a lower rate and then reconstructing the original signal from fewer data points.

Abstract: A method and control system that monitors the high frequency or commonly referred to as the “noise” component of a measurement signal to detect plugging conditions in fluid flow systems monitored by DP-cell based sensors. This high frequency component has contributions from the process factors like disturbances, user actions and random effects like turbulence. A test statistic &thgr;(t) has been developed that monitors the proportion of variance introduced by the first two factors and the third factor. By monitoring this proportion, it is possible to detect a frozen sensor that is characterized by a dramatic reduction in the variance due to process factors over a sufficiently long detection window. The method and control system uses random sampling intervals to improve data quality. The sampling rate is also reduced by taking samples at a lower rate and then reconstructing the original signal from fewer data points.

Abstract: A flowmeter detector for determining the flow volume of a fluid medium that includes a measuring line having first and second ends and a fluid medium entry and exit ports adjacent the fist and second ends and fluid medium flowing between the entry and exit ports is disclosed. An acoustic transducer is located at each end of the measuring line and each acoustic transducer has an overall dimension less than the cross-section diameter of the measuring line. The acoustic transducers are first operated to simultaneously transmit pulsed acoustic energy into the measuring line. The transducers are subsequently operated to receive the acoustic energy propagated through the measuring line. The flow volume is determined by evaluating the difference in the travel times of the pulsed acoustic energy propagated through the measuring line.

Abstract: The apparatus of the invention includes a sensor header and a sensor cover which are coupled to a prior art diaphragm assembly. The sensor header is provided with two piezoresistive silicon membrane strain gauges. One side of both strain gauges is exposed to fluid at upstream high pressure. The other side of the first strain gauge is exposed to fluid at downstream low pressure and the other side of the second strain gauge is exposed to the atmosphere. The sensor header is provided with a first port which is fluidly coupled to the first membrane strain gauge and extends to the surface of the header at a first location. The sensor header is provided with a second port which is fluidly coupled to the second membrane strain gauge and extends to the surface of the header at a second location. The sensor cover defines two isolated annular spaces around the sensor header, a first annular space around the first location and a second annular space around the second location.

Abstract: A meter body for use in a pressure transmitter in a continuous pressurized transmission system. The meter body is cylindrical in form with a bottom end (including a flexible diaphragm) adapted to engage a flexible gasket to form a so-called "sanitary-seal" connection. The top end is configured to be connected to a sensor capsule.

Abstract: A manifold which mounts a transmitter to a pipeline comprises a body of rectangular-like shape. The body has a first surface and a second surface at right angles to the first surface. The second surface of the body includes a first and second input port, and the first surface of the body includes corresponding first and second output ports. The body also includes a first and second channel internal to the body such that fluid is conducted between the first input port and the first output port, and fluid is conducted between the second input port and the second output port. The body further includes an internal crossover channel between the first channel and the second channel. A third channel is provided internal to the body for permitting steam to flow therein, thereby providing heat to the manifold. A first and second valve is included for controlling the conducting of fluid in the first channel and the second channel, respectively.

Abstract: A manifold which mounts a transmitter to a pipeline comprises a body of rectangular-like shape. The body has a first surface and a second surface at right angles to the first surface. The second surface of the body includes a first and second input port, and the first surface of the body includes corresponding first and second output ports. The body also includes a first and second channel internal to the body such that fluid is conducted between the first input port and the first output port, and fluid is conducted between the second input port and the second output port. The body further includes an internal crossover channel between the first channel and the second channel. A first and second valve is included for controlling the conducting of fluid in the first channel and the second channel, respectively. A third valve is included which controls the flow of fluid in the internal crossover channel.

Abstract: A pressure transmitter comprises a first housing having a first and second diaphragm for receiving a first and second process fluid under a first and second pressure, respectively. The first and second diaphragm is deflected in response to the first and second pressure of the process fluid. A second housing includes a printed wire board. A first and second capillary tube is included, the first capillary tube being operatively coupled to the first diaphragm and the second capillary tube being operatively coupled to the second diaphragm, each corresponding capillary tube having an internal fluid therein. A sensor package, having a sensor element, is mounted internally within the second housing, and is coupled to the first and second capillary tubes such that the sensor element provides a first signal which is coupled to electrical circuit components mounted on the printed wire board to output a signal representative of the differential pressure of the process fluid.

Abstract: The apparatus for sensing pressure comprises a header, having at least one input port for receiving a substance under pressure. A substrate, having a wafer-like shape with a relatively large surface area in comparision to its thickness, includes at least one internal passage to couple the substance under pressure. A pressure sensing element is mounted onto the surface of the substrate over an exit port of the internal passage coupling the substance under pressure. The substrate is bonded to a surface of the header at extreme locations from a location in which the pressure sensing element is mounted. Thus isolation is provided for the pressure sensing element from unwanted stresses induced in the substrate.

Abstract: A pressure sensor package, having a dual-in-line package (DIP) structure as commonly used in the semiconductor industry, comprises a first layer of predetermined material, having at least one internal passage for transmitting a fluid under pressure from a first surface of the first layer to a second surface of the first layer. A pressure sensitive element is bonded to the first surface of the first layer, and covers an exit from the first surface of the internal passage. A lead package, has a plurality of pins, each pin being perpendicular to the first surface of the first layer and placed along a first and second length of the first layer exterior to the pressure sensor package, and having a spacing conforming to the DIP configuration. Predetermined points of the pressure sensitive element are electrically connected to predetermined pins. A second layer of predetermined material is bonded to the first surface of the first layer providing an enclosed spaced for the pressure sensitive element.

Abstract: An absolute pressure transducer includes a hollow glass tube supporting across one end thereof a differential pressure responsive semiconductor plate having piezoresistive elements diffused therein and an evacuated sealed chamber within the tube exposed to the plate. A method for making the transducer and providing the evacuated chamber within the tube adjacent to the plate includes the steps of mounting the plate across the end of the tube to form a first fluid-tight seal therewith, inserting a loose glass plug within the tube to define the chamber, exposing the interior of the tube to a vacuum, concurrently heating the tube in the vicinity of the plug to allow the heated tube wall to constrict around the plug in response to the internal vacuum and to fuse with the plug to form a second fluid-tight seal therewith and allowing the tube and plug to cool to trap the vacuum in the chamber.

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

Abstract: A pressure sensor header uses a layered assembly of a first and a second metal layer with an intermediate ceramic layer having a radial surface groove providing a fluid passage between a peripheral fluid port and a hole extending through the first layer between the groove and an outer surface of the first layer. A plurality of electrically conductive pins are arranged to extend through the layered assembly and are sealed to the upper and lower metal headers with glass seals to provide a fluid-tight seal. The seals on the metal pins provide a means for retaining the layered assembly in a predetermined configuration while the radial groove and the hole through the first layer provide a fluid path to a pressure transducer element supported on the first layer of the header and having an internal fluid path aligned with the hole through the first layer. Electrical connections to the metal pins provide electrical signal paths between the transducer element and associated electrical circuits.

Abstract: A fluid differential pressure transmitter assembly includes a pressure sensor housing having a spacer within the housing to minimize the internal fill fluid used to conduct fluid pressure from a fluid inlet port to a pressure sensor located within the housing in the form of a pressure responsive diaphragm. Input pressures are applied to respective sides of the diaphragm to produce an electrical signal output representative of the differential pressure from piezoresistive elements deposited on the diaphragm. The sensor is electrically connected by flexible wires to electrically conductive paths supported on an end surface of the spacer. The conductive paths are, in turn, electrically connected to electrode wires at electrically conductive support junctions between the spacer and the electrode wires.

Abstract: A butterfly valve having a valve body and a valve disc which is rotated to produce an engagement with a peripheral edge of the disc and an annular seat or wall defined by a portion of an internal fluid passage in the valve body uses a seal ring member mounted in an annular groove in the valve body adjacent to the annular seat. The seal ring member includes a pair of bowed seal rings arranged in a "V" within a triangular shaped annular recess in the wall of the fluid passage in the valve body. One side, i.e., an inner side, of each of the seal rings projects from the triangular recess to contact the edge of the valve disc to form a fluid-tight seal in response to fluid pressure acting on a convex face of a seal ring to flatten the seal ring. The other side of each of the seal rings contacts a respective corner of the recess with the convex faces of the seal rings facing each other.

Abstract: A distance measuring apparatus and a differential pressure transmitter utilizing the same having an ultrasonic element reflector mounted between a pair of ultrasonic transducers. The alternate operation of the ultrasonic transducers produces a pair of transducer energizing signals which are related to the relative separation of the reflector element from the transducers. In one embodiment, the reflector element is mounted within a closed pressure vessel divided internally by an ultrasonic reflector diaphragm with a pair of fluid inlet lines admitting respective pressurized fluids to corresponding sides of the reflector diaphragm.