Abstract: A method and apparatus for preventing flow rate errors derived from an ultrasonic flow meter utilized in semiconductor fabrication operations. The ultrasonic flow meter is generally configured to include an extension chamber connected to a thin branch tube of the ultrasonic flow meter. A venturi tube can be positioned at an outflow location of the ultrasonic flow meter, such that the thin branch tube is broached into the venturi tube, wherein bubbles contained in a slurry flow are forced directly into the outflow location to thereby prevent inaccurate flow measurements derived from the ultrasonic flow meter. The extension chamber may be configured to reduce an inflow velocity associated with the slurry slow and ensure that the bubbles with not drift with the slurry flow. Additionally, a diameter of the branch tube may be configured such that the diameter is much smaller than a diameter associated with an inflow and/or outflow tube of the ultrasonic flow meter.

Abstract: An improved method and system for measuring a multi-phase flow in a pressure flow meter. An extended throat venturi is used and pressure of the multi-phase flow is measured at three or more positions in the venturi, which define two or more pressure differentials in the flow conduit. The differential pressures are then used to calculate the mass flow of the gas phase, the total mass flow, and the liquid phase. The system for determining the mass flow of the high void fraction fluid flow and the gas flow includes taking into account a pressure drop experienced by the gas phase due to work performed by the gas phase in accelerating the liquid phase.

Abstract: An apparatus for sampling the emission content of an exhaust gas from an exhaust source has an exhaust inlet adapted for connecting the exhaust source with a venturi metering device for measuring the flow rate of the exhaust gas. The venturi metering device includes a housing having an entrance section, a throat section, and an exit section, the throat section having a smaller diameter than the entrance and exit sections. The housing includes first and second pressure transducers that produce an electrical output that characterizes the pressure that the pressure sensing means senses, the electrical outlet enabling a computer of the venturi metering device to accurately measure the pulsating flow of the exhaust gas in both directions.

Abstract: An air is fed from an air supply source to a detecting nozzle via a first fixed throttle section. The air is jetted from the detecting nozzle to the workpiece W to obtain a nozzle back pressure for detecting a position of a workpiece W. A first diffuser section is disposed downstream of the first fixed throttle section.

Abstract: A method and apparatus for fluid flow straightening and measurement introduces a venturi in-line with existing conduit. A fluid velocity measuring device is positioned in the throat of the venturi and measurements of velocity at multiple points in a plane perpendicular to the direction of fluid flow are taken. The velocity data points are then averaged and produce an output signal from which fluid flow rate can be determined.

Abstract: A pressure signal from a differential pressure transducer is dynamically compensated for error, such as zero point drift, due to time passage or temperature change. A processor associated with a pressure transducer employs an algorithm to continuously monitor the pressure signal to determine when signal characteristics indicate zero signal level. Then the algorithm determines a current correction factor or updates a previously determined correction factor, and records the current correction factor in a non-volatile memory as a function of ambient temperature. When the signal characteristics indicate other than a zero signal level, such as when differential pressure is non-zero, the algorithm recalls from memory and applies the most recently determined correction factor for a corresponding ambient temperature. Suitable time intervals for determining a current correction factor are found by monitoring the process signal and seeking those time periods when the signal is both calm and quiet, i.e.

Abstract: A flow rate and flow velocity measurement device has a divided flow pipe (332) which is attached so as to be orthogonal to an intake pipe (1) of an engine, and into which a flow in the intake pipe (1) is introduced, an inlet plate (334) which extends in a direction orthogonal to a flow direction in the intake pipe (1) and forms a U-shape form pipe passage in the divided flow pipe (332) and a detection element (331) which is disposed so as to be exposed to a flow in the divided flow pipe (332) outside the intake pipe (1) and detects a flow rate and a flow velocity, wherein one end of the inlet plate (334) protrudes into the intake pipe (1) while passing a top opening of the divided flow pipe (332), and the divided flow pipe (332) has a flow passage structure symmetrical with the detection element (331) being made a center, so that an equivalent detection element (331) output is obtained in regard to both cases in which a fluid flows through the intake pipe (1) in a normal direction and a reverse direction.

Abstract: A fluid flow device for determining fluid flow rates in soils includes a conduit for receiving a fluid. The conduit has a reduced channel portion to form a reduced channel portion which amplifies the fluid flow rate of the fluid. A sensor device is coupled in sensing relation relative to the conduit and configured for measuring the amplified fluid flow rate as the fluid flows through the reduced channel portion.

Abstract: Improvement in a mass air flow meter having a static pressure manifold disposed upstream from an air flow path for sample air and capable of accumulating a volume of air therein, the flow path constructed to receive an air flow transducer, the static pressure manifold having an inlet arrangement in communication with the kinematic main air flow traveling through the meter so as to be capable of sensing different static pressures thereof, the static pressure manifold having a single outlet serving as the sole inlet for the sample air to be measured by the air flow transducer, the static pressure of the air accumulated in the static pressure manifold being such that it functions as a resultant average of the different static pressures sensed at its inlet arrangement, the static pressure manifold providing substantial immunity for the meter in respect to turbulent air flow upstream therefrom.

Abstract: A precision flowmeter is adapted to measure at least one of mass flow rate and flow velocity of a fluid, at steady or transient state, in a bi-directional low-velocity flow system. The flowmeter includes pressure taps and static pressure taps, passing from the interior of a tubular main body and through a wall of the tubular main body, and a plurality of impact tubes located circumferentially spaced-apart and extending axially parallel through a conical wall of the tubular main body toward a center of the cylindrical throat portion. The pressure taps correspond in number to the plurality of impact tubes and communicate with inner ends of the corresponding plurality of impact tubes, and static pressure taps pass through walls of the upstream and downstream tubular channel sections and through the tubular throat portion. A method for measuring at least one of flow rate and flow velocity of a fluid is also disclosed.

Abstract: A method of determining a rate of flow of a first gas in a pipe includes placing a flow-restricting device in the pipe such that the device and/or the pipe define a first channel section and a second channel section. The second channel section is disposed downstream from the first channel section. The first channel section has a first cross-sectional area. The second channel section having a second cross-sectional area less than the first cross-sectional area. A source of a second gas is provided in fluid communication with the second channel section. A low pressure in the second channel section is caused by an increased flow velocity and creates a flow of the second gas into the second channel section. A rate of a flow of the second gas into said second channel section is measured. A mathematical relationship between the rate of the flow of the second gas into the second channel section and the rate of flow of the first gas in the pipe is ascertained.

Abstract: A flow rate detector mechanism using variable Venturi therein, comprising: a variable flow rate generator, comprising: a core 11; and a variable Venturi 12; wherein a throat (flow passage) cross-sectional area defined between the core and the venturi is able to be changed by shifting relative positions of the core and the venturi in a direction of axes thereof, and further comprising a flow rate calculation processing portion 30 for calculating a flow rate based on the relative positions in the direction of the axes thereof and for outputting the calculated flow rate, thereby continuously changing the constant flow rate, without occurrence of any disturbance therein.

Abstract: The invention relates to a flow rate measurement method adapted to oil effluents made up of multiphase fluid mixtures comprising water, oil, and gas. The effluent is passed through a Venturi in which the effluent is subjected to a pressure drop (&Dgr;p), a mean value (<&Dgr;p>) of the pressure drop is determined over a period t1 corresponding to a frequency f1 that is low relative to the frequency at which gas and liquid alternate in a slug flow regime, a mean value (<&rgr;m>) is determined for the density of the fluid mixture at the constriction of the Venturi over said period t1, and a total mass flow rate value <Q> is deduced for the period t1 under consideration from the mean values of pressure drop and of density.

Abstract: The invention relates to a method of characterizing an oil borehole effluent, formed by a multiphase fluid mixture typically containing water, oil, and gas. According to the invention, a gadolinium 153 source is used to emit gamma rays at a first energy level of about 100 keV and at a second energy level of about 40 keV, and the attenuation of the gamma rays at these two energy levels is measured after the rays have passed through the effluent.

Abstract: A method is provided for measuring fluid flow characteristics in a multiphase fluid stream which passes through a venturi flow meter. The liquid holdup (&agr;1,I) is measured at or near the inlet of the venturi and a slip factor (S) is determined. The slip factor expresses the difference between the gas and liquid velocity at a selected location in the venturi and is based on the measured level of liquid holdup. The fluid flow characteristics are calculated on the basis of an algorithm which takes into account the measured liquid holdup (&agr;1,I) at the inlet of the venturi and different slip factors at the inlet (Si) and in the throat of the venturi (St).

Abstract: A device for measuring fluid flow rates has a body defining a conduit for the fluid, the body having selectable first and second configurations, in the first configuration the body presents a first constriction in the conduit for measuring a first range of fluid flow rates, and in a second configuration the body presents a second construction in the conduit for measuring a second range of fluid flow rates, the second constriction being narrower than the first constriction, the body being arranged for operative connection to parts for determining the pressure difference between each constriction.

Abstract: The present invention relates to an adaptable controller for controlling environmental systems, and more particularly to an improved computer-controlled irrigation and lighting system. Scheduling is selected using a unique graphical user interface and is transmitted to the controller remotely. Sensing devices for water flow to determine leaks and calculate usage using venturi are provided which communicate with the controller to adjust output in real time based on the measurements.

Abstract: An improved method and system for measuring a multiphase flow in a pressure flow meter. An extended throat venturi is used and pressure of the multiphase flow is measured at three or more positions in the venturi, which define two or more pressure differentials in the flow conduit. The differential pressures are then used to calculate the mass flow of the gas phase, the total mass flow, and the liquid phase. The method for determining the mass flow of the high void fraction fluid flow and the gas flow includes certain steps. The first step is calculating a gas density for the gas flow. The next two steps are finding a normalized gas mass flow rate through the venturi and computing a gas mass flow rate. The following step is estimating the gas velocity in the venturi tube throat.

Abstract: A flowmeter used to measure the flow rate of a fluid in a conduit includes a flow restrictor insert. The conduit is coupled to an upstream and downsteam conduit portion and includes three pressure measuring stations axially spaced along the conduit wall. The flow restrictor insert includes two cylindrical portions, the second of which has a diameter larger than the first. The flow restrictor insert is positioned in the flowmeter conduit such that the first cylindrical portion is aligned with the second pressure measuring station and the second cylindrical portion is aligned with the third pressure measuring station. When a fluid flows through the conduit, the flow restrictor insert causes the fluid to diverge around the cylindrical portions thereby creating a venturi effect. The fluid flow rate is calculated from the pressure differentials derived from the data measured at the three pressure measuring stations.

Abstract: A flow rate and flow velocity measurement device has a divided flow pipe 332 which is attached so as to be orthogonal to an intake pipe 1 of an engine, and into which a flow in the intake pipe 1 is introduced, an inlet plate 334 which extends in a direction orthogonal to a flow direction in the intake pipe 1 and forms a U-shape form pipe passage in the divided flow pipe 332, and a detection element 331 which is disposed so as to be exposed to a flow in the divided flow pipe 332 outside the intake pipe 1 and detects a flow rate and a flow velocity, wherein one end of the inlet plate 334 protrudes into the intake pipe 1 while passing a top opening of the divided flow pipe 332, and the divided flow pipe 332 has a flow passage structure symmetrical with the detection element 331 being made a center, so that an equivalent detection element 331 output is obtained in regard to both cases in which a fluid flows through the intake pipe 1 in a normal direction and a reverse direction.

Abstract: A multiphase flowmeter (30) is mounted on the piping via which a multiphase fluid flows out from a hydrocarbon well, so as to measure the flow rates of the various phases of the fluid. A back-pressure valve (34) is placed in the piping downstream from the flowmeter (30) so as to enable the pressure in the flowmeter to be adjusted, whereby the flow conditions of the fluid in the flowmeter (30) can be made compatible with the measurement domain of the flowmeter.

Abstract: The invention is an apparatus and a method for characterizing the flow of a multi-phase fluid. The fluid is first mixed continuously as it flows from a first to a second end of a first section, such that the fluid is substantially homogeneous at a first point and such that the substantial homogeneity of the fluid is maintained between the first point and a second point in the first section, and a first pressure drop is measured at a first location in the first section between the first and second points. The fluid is second mixed continuously as it flows from a first to a second end of a second section, such that the fluid is substantially homogeneous at a first point and such that the substantial homogeneity of the fluid is maintained between the first point and a second point in the second section, and a second pressure drop is measured at a second location in the second section between the first and second points.

Abstract: An assembly for measuring the mass flow and flow rate of gases such as are used in semiconductor fabrication processes. The assembly includes an axial flow passage, viz., a capillary tube with a bore of about 0.050 inch diameter and a wall thickness of about 0.002 inch, having a downstream end connected to a diffuser section having an axially symmetric, diverging passage. Gas exiting the diffuser section has a low pressure drop because the gas has expanded at a low, controlled rate, converting velocity head into pressure head, and because the tube and diffuser section passage are in-line, eliminating right-angle turns. The assembly also includes two resistance thermometers, coils of iron-nickel alloy wire about 0.0004 inch in diameter, providing a differential temperature measurement with a time constant of less than 4 seconds.

Abstract: An air induction assembly 10 disposed in an intake passage through which air flows to an engine. The air induction assembly 10 has a conduit member 20 which defines an air flow path. A mass air flow sensor (MAFS) 30 is located in the intermediate conduit portion and is in fluid communication with the air flow path. The MAFS 30 being operative to generate an output signal corresponding to air flow rate within the intermediate conduit portion A plurality of flow conditioning elements (FCEs) 22 in the airflow path produce a uniform airflow with low turbulent fluctuations to the MAFS 30 under all vehicle and engine speeds without excessively restricting the air flowing to the engine.

Abstract: A valve assembly for use in heating, ventilating and air conditioning systems. The valve assembly includes a valve body having a chamber in which is rotatably mounted a quarter-turn flow control ball valve. A valve body nut having an outlet port is threadably mounted on the valve body adjacent the outlet end of the valve body chamber. A flow venturi is removably mounted in the inlet end of the valve body. A pipe union tailpiece is detachably mounted on the inlet end of the valve body. A pair of pressure/temperature readout ports are mounted on the valve body for use in determining the rate of fluid flow through the venturi. A vent plug is mounted on the valve body for venting air from the ball valve chamber.