Abstract: An insertion-type vortex flowmeter that includes an obstruction element removably and replaceably disposed within a pipe. The obstruction element is configured to only partially span the inner diameter of the pipe, and employs multiple flange sub-assemblies to mount the obstruction element to the pipe. The flowmeter also employs a fluid conditioning element that has a major axis that extends axially within the pipe and transverse to the obstruction element.

Abstract: A solid state transducer is provided for a Coriolis flow meter having a flow tube adapted to vibrate at a predetermined resonance frequency to determine mass flow rate of a fluid passing therethrough. The driver includes a strain element, such as an elongated piezoelectric or magnetostrictive element fastened axially along the wall of the tube. The strain element is adapted to oscillate in the axial direction along with the tube wall to generate and/or sense vibration of the tube in response to. The transducer may be utilized as a driver or alternatively, as a sensor wherein the transducer is oscillated along with oscillation of tube wall in the axial direction to generate an output signal responsive thereto.

Abstract: An electropneumatic motor includes an electrically energizable magnetic circuit with an armature resiliently suspended in the air gap defined between two opposed pole pieces of differing dimensions. One of pole pieces includes an axially adjustable member of magnetic material. A fluid nozzle is carried by the other pole piece. Axial adjustment of the pole piece member affects the strength of the magnetic field. In one embodiment, the pole piece member includes a permanent magnet, which is axially movable relative to the armature, centered in the face of the pole piece. The combination of the fixed field from the permanent magnet and the electromagnetically induced variable field helps more nearly linearize the current to armature force relationship and increases the force on the armature. To determine the operating point of the motor, the suspension for the armature can be prestressed to force it as close as possible to the nozzle, and the magnet can be advanced until the armature is pulled off of the nozzle.

Abstract: A method of reducing noise in a mass flow measuring system includes equalizing the ratio of stiffness to mass of a sleeve located in a flow path to the ratio of stiffness to mass of a rod located within the sleeve. The method further includes recognizing a frequency signal from two capacitive sensors mounted to sense axial deflection of the sleeve relative to the rod. The frequency signal is twice the frequency signial from two capacitive sensors mounted to sense lateral deflection of the sleeve relative to the rod. An output of the capacitive sensors for sensing lateral deflection is connected to a conductance circuit and an output of two additional capacitive sensors mounted to sense lateral deflection is connected to the another conductance circuit. The method includes adjusting an output of one of the conductance circuits such that the sum of the outputs is zero.

Abstract: A vortex mass flowmeter includes a body for placement in a flow path of a fluid and four capacitive sensors. The body has a sleeve and a rod positioned within a chamber in the sleeve. Two of the capacitive sensors are mounted to sense lateral deflection of the sleeve relative to the rod and two of the capacitive sensors are mounted to sense axial deflection of the sleeve relative to the rod, thereby providing frequency signals related to shedding and drag, respectively. The shedding signal is dependent on the flow velocity, and the drag signal is dependent on the flow velocity and the fluid density.

Abstract: A magnetic flowmeter has a tube for carrying fluid along a longitudinal axis. The tube has faces transverse to the longitudinal axis and disposed at opposite ends of the tube. A liner on the inner surface of the tube extends out from an end of the tube and into a recess on one face to anchor the liner in place.

Abstract: A dual sensor vortex flow meter providing fluid connections for two sensors and containing isolation valves providing the further capability of separate valve control of the fluid communication to each of the dual sensors is herein disclosed. The vortex flow meter is mounted onto a flow meter body having an existing sensor cavity for housing a single sensor. The vortex flow meter is fitted into the existing sensor cavity by means of a dummy-cast sensor. On either side of the dummy sensor are apertures coupled to flow passages that transmit the alternating differential pressure fluctuations caused by the vortices from each side of the dummy sensor to the corresponding sides of each of the dual sensors. The dual sensor vortex flow meter may also include valves for controlling the process flow transmission to each of the sensors.

Abstract: A sensor for use in a vortex flow meter which is capable of measuring various physical characteristics of a flow in a single process penetration from a common source. A shedder bar in the vortex meter generates alternating vortices. The sensor is located in the shedder bar within the stream of the fluid flow. The shedder bar serves as a composite vortex-generating plate and sensing unit. The shedder bar is structured such that it is either removable from the flow pipe for calibration, replacement, cleaning and the like or is permanently welded into the flow pipe with smooth or rigid contact surfaces. The sensor comprises one or more sensing diaphragms containing piezoresistor elements arranged in a Wheatstone bridge configuration. The sensor produces electric signals indicative of flow velocity, fluid pressure, and temperature. These signals are transmitted to a processing element which computes additional flow parameters.

Abstract: A sensor for use in a vortex flow meter capable of measuring various physical characteristics of a flow in a single process penetration from a common source. A shedder bar in the vortex meter generates alternating vortices. The sensor, which is fluidly connected to the vortex meter, comprises one or more pressure and temperature sensing diaphragms containing piezoresistor elements arranged in a Wheatstone bridge configuration. The sensor produces electric signals indicative of flow velocity, fluid pressure, and temperature. These signals are transmitted to a processing element which computes additional flow parameters.

Abstract: An external electrode seal assembly (10) for magnetic flow meter tubes (12) is disclosed. The assembly includes a polymeric gasket (36) compressed between a head portion of an electrode (17) and an external seal area (18) of a ceramic tube (12). A stem portion (30) of the electrode extends from the head portion (28) to the interior wall (26) of the tube and is in contact with process fluid flowing through the tube. A clamp assembly (42) compresses the polymeric gasket (36) between the head portion (28) of the electrode (17) and the ceramic tube (12) to form the seal.

Abstract: A vortex sensor 14 measures a flow rate of a fluid flowing through a flow passage by detecting alternating pressure variations 26a and 28a generated by a shedding body 16 placed in the flow passage. The vortex sensor 14 includes a sensor housing 32 enclosing piezoelectric sensing elements 62, 64 which are acted on by a movable member 30. The lifetime of the sensing elements in the closed interior is enhanced by providing surface barriers, oxidizing exposed interior surfaces, or providing a gas reservoir. In applications where fluid leakage may be accepted, a controlled leak restrictor provides a limited rate diffusion path to the atmosphere allowing a minimum partial pressure of oxygen to be maintained.

Abstract: A vortex sensor 14 for measuring a flow rate of a fluid flowing through a flow passage. The flow rate is measured by detecting alternating pressure variations 26a and 28a generated by a shredding body 16 placed in the flow passage. The vortex sensor 14 includes a sensor housing 32 having two cavities 44 and 46 interconnected by a channel 42. An Axle 52 of a spool member 34 is slideably disposed in the channel 42 and allows each of two flange members 54 and 56, connected proximate each end of the axle 52, to shuttle back and forth with respect to the sensor housing 32. A piezoelectric sensing element 62, 64 and a biasing mechanism 58, 60 are disposed between the flange members 54 and 56 and the sensor housing 32. The alternating pressure variations are applied to each flange member 54, 56 causing the spool member 34 to shuttle back and forth. When the spool 34 moves, mechanical forces are coupled to each sensing element 62 and 64 by biasing mechanisms 58 and 60.

Abstract: A seal for ceramic flow tubes resistent to high temperature, pressure and corrosion factors is made by fusing a first polymer to the ceramic as a binding layer, fusing to the first layer a second flexible polymer layer chemically and temperature resistent to the process fluid, and holding the two layers under a resilient loading. The seal is highly leak tight, chemically durable, inexpensive to produce and repairable without sacrificing valuable components.

Abstract: A double-tuning-fork (DTF) resonator having electrical circuitry operable, if either tine breaks, to develop a characteristic electrical circuit condition which is detected to produce an indication of failure. In one preferred embodiment, the circuitry includes a dual series circuit for energizing the electrodes on the DTF tines, with (1) a first series circuit passing down one tine to the remote end thereof, across the support segment at that end of the DTF, and back up the other tine, and (2) a second series circuit passing down the other tine to the remote end thereof, across said support segment at that end, and back up the first-mentioned tine. If either tine breaks, or if there is fracture of another part of the DTF carrying an electrode energizing lead, vibratory excitation of both tines ceases, and the output signal is caused to go to a level (e.g. zero) clearly indicating failure of the instrument.

Abstract: A resonant wire instrument for producing a measurement signal, which is derived from the resonant frequency of a vibratable wire tensioned in accordance with the magnitude of a physical variable being measured, wherein a force impulse produced mechanically by an apparatus is applied to displace laterally one end of the vibratable wire so as to excite the wire into resonant motion. In one embodiment, the one end is rigidly attached to a housing and a piston applies a transverse force impulse to that end by momentarily striking the housing. In another embodiment, the one end is connected to a piezoelectric crystal which responds to a short-duration electric field to displace momentarily that end.

Abstract: An ultrasonic flowmeter of the upstream/downstream sonic propagation type includes two transducers mounted externally on the same side of a flow conduit. The transducers are coupled to respective sonic probes which transmit and receive acoustic pulses between the transducers through the fluid by "bouncing" the pulses off the opposite pipe wall. Additionally the meter maintains a smooth bore in the measurement region so that the acoustic pulses are refracted at the probe/fluid interface and hence propagate along a sonic path that varies depending on the sonic velocities within the fluid and the probe. An acoustic path of known length is included within at least one of the probes along which a portion of the generated acoustic pulses propagates, thereby providing for a third sonic measurement which represents the transmit time in the probe.

Abstract: A gas chromatograph having a pneumatic detector adapted to produce a component concentration measurement signal that is relatively unaffected by changes in carrier flow rate. The detector includes an orifice connected in the flow stream at the output end of the chromatographic column to produce a pressure signal responsive to density. This orifice signal also responds to flow rate of the fluid passing through the column. A capillary is connected in series with the orifice to produce a second flow-responsive pressure signal which is subtracted from the orifice signal in a way to effectively eliminate changes in the final measurement output signal due to changes in flow rate while leaving the signal variations due to changes in density, i.e. concentration.

Abstract: An all-pneumatic process chromatograph having a pneumatically-actuated sample-injection valve, an orifice connected in the column output line to develop a pressure signal corresponding to fluid density, a pneumatic amplifier for strengthening the pressure signal, and pneumatically-operated control means for developing a periodic sample-valve actuating signal and for selecting a particular peak of interest at a controllable time following injection of the sample. The pneumatic control means includes means automatically operable to adjust the time of peak selection in response to changes in actual peak elution time. The temperature-sensitive elements of the apparatus are contained in a chamber which is heated by a source of steam heat, with the rate of heat transfer being regulated pneumatically to maintain a relatively constant temperature within the chamber.

Abstract: A gas chromatograph having a pneumatic detector adapted to produce a component concentration measurement signal that is relatively unaffected by changes in carrier flow rate. The detector includes an orifice connected in the flow stream at the output end of the chromatographic column to produce a pressure signal responsive to density. This orifice signal also responds to flow rate of the fluid passing through the column. A capillary is connected in series with the orifice to produce a second flow-responsive pressure signal which is subtracted from the orifice signal in a way to effectively eliminate changes in the final measurement output signal due to changes in flow rate while leaving the signal variations due to changes in density, i.e. concentration.

Abstract: An all-pneumatic process chromatograph having a pneumatically-actuated sample-injection valve, an orifice connected in the column output line to develop a pressure signal corresponding to fluid density, a pneumatic amplifier for strengthening the pressure signal, and pneumatically-operated control means for developing a periodic sample-valve actuating signal and for selecting a particular peak of interest at a controllable time following injection of the sample. The pneumatic control means includes means automatically operable to adjust the time of peak selection in response to changes in actual peak elution time. The temperature-sensitive elements of the apparatus are contained in a chamber which is heated by a source of steam heat, with the rate of heat transfer being regulated pneumatically to maintain a relatively constant temperature within the chamber.