Abstract: According to one embodiment of the invention, a computerized method for determining a flow rate of a fluid flowing through a conduit having an obstruction flow meter includes receiving a &bgr; ratio value indicative of a &bgr; ratio of the obstruction flow meter, receiving a pressure differential value indicative of a pressure differential across the obstruction flow meter, receiving a density value indicative of a density of the fluid, receiving a discharge coefficient formula for the obstruction flow meter, the discharge coefficient formula being a function of the &bgr; ratio of the obstruction flow meter and an Euler number for the fluid flowing through the conduit, and determining, by the computer, the flow rate based on the received &bgr; ratio value, the received pressure differential value, the received density value, and the received discharge coefficient formula. The determined flow rate may either be the volumetric flow rate or the mass flow rate.

Abstract: A method for controlling an engine during sensor degradation uses a remaining active sensor. The engine has an exhaust gas recirculation system utilizing pressure sensors upstream and downstream of an orifice. The downstream pressure sensor is coupled to the engine intake manifold and is also used for engine air-fuel ratio control.

Abstract: The goal is to reliably diagnose and compensate for a change in the gas flow passing through an exhaust gas recirculation line. For this purpose, according to a first method, the mass flow passing through the exhaust gas recirculation line is derived as a function of the position and the flow characteristic of the exhaust gas recirculation valve, and, according to a second method, the mass flow is derived from the fresh-air mass flow in the induction pipe and from the induction pipe pressure. Then the difference is determined between the mass flows as ascertained in accordance with the two methods, and from the difference one or plurality of correcting quantities is generated for the mass flow that is derived as a function of the valve position and of the flow characteristic.

Abstract: An integrated module is provided for measuring a flow rate of a fluid, whether gaseous or liquid, with a flow restrictor comprising a plurality of orifices adapted to a flow channel of the integrated module and a sensor mounted to measure a property of the fluid at said flow restrictor corresponding to the flow rate. The integrated module provided may be used in numerous flow systems, such as reactors, ventilators and respirators, and has the benefit of better laminarization of the flow as well as better calibration between the flow sensor and the flow restrictor for more accurate flow measurements.

Abstract: A process flow device that includes a self-averaging orifice plate type of primary flow element for measuring, by a differential pressure process, the volumetric rate of fluid flow at a point in a fluid carrying conduit where the velocity profile of the fluid is asymmetric with respect to the longitudinal axis of the conduit. The improved flow element comprises a planar flow-impeding plate disposed transversely across the interior of the conduit and perpendicular to the longitudinal axis thereof. The plate includes at least three circular apertures eccentrically disposed with respect to the longitudinal axis of the conduit to create static pressure averaging on the downstream side of the plate. Upstream and downstream static pressure sensing ports are respectively provided on opposite sides of the flow impeding plate.

Abstract: An exhaust gas recirculation systems directs exhaust gasses from an exhaust manifold to an intake manifold of an internal combustion engine. The exhaust gasses travel from the exhaust manifold, first passing through a flow control valve and then through a measuring orifice before entering the intake manifold. Pressure upstream of the orifice is used, along with correction pressure downstream of the orifice, to measure and control exhaust gas flow. Further, manifold pressure is determined from downstream pressure and the used along with the measured exhaust gas flow to calculated a cylinder air charge amount.

Abstract: A coupling having an integral orifice plate engages upstream and downstream segments of a landfill piping system. Upstream and downstream ports are respectively formed through the walls of the coupling adjacent the orifice plate. The difference in pressure at the ports is correlated to a flow rate through the pipe. Sensor fittings are threadably engaged with the ports, and to support the threadable engagement, the wall of the coupling through which the ports are formed has a thickness of at least around one-half inch.

Abstract: A differential flow plate insertable into a flow path including a flow interrupter extending about an outer periphery of the flow path forming a constricted flow opening and a temperature sensor channel disposed proximate to the flow interrupter.

Abstract: Semi-spherical supports are used in the piercing of small, consistently sized holes in a soft metal. In particular, a flow control device, such as an orifice plate, can be fabricated with small, consistently sized flow apertures to regulate flow in a gas flow regulating device. By using semi-spherical supports, the need for hand-punching and real-time flow calibration can be avoided and automated machinery with a tapered piercing tool can be used to fabricate the flow control device.

Abstract: A housing of a fume hood includes walls defining a chamber for containment of air therein. One of the walls defines an air passageway opening into the chamber, and a sensor is located outside of the chamber and measures airflow velocity through the air passageway into the fume hood. An elongate, perforated tubular member supported within the chamber includes a first end mounted to the wall of the chamber defining the air passageway in surrounding relation thereto, and a second, distal end substantially closed off from the contaminated air within the chamber whereby airflow through the air passageway into the fume hood generally must pass through a perforation in the tubular member to gain access into the air chamber. The tubular member extends across the width of the chamber and airflow velocity through the air passage is representative of overall air entry velocity into the air chamber.

Abstract: A flow meter for use in a flow stream with a tubular housing, including a fluid inlet and a fluid outlet, in the flow stream, with the inlet pressure exceeding the outlet pressure. The interior has an orifice defined in a crystalline silicon membrane, along crystal planes of the silicon so that the geometry of the orifices is precisely known and has a sharp knife edge rim profile. Where the fluid is a gas, pressure and temperature transducers measure conditions inside of the housing for application of gas law principles. By using instantaneous pressure and temperature in the chamber, mass flow through the outlet orifices of the chamber is computed and delivered as an output signal.

Abstract: An air flow measurement device includes a connector conduit with a constant inner diameter wall for the air flow, a transverse restrictor plate located within the conduit with a plurality of generally uniformly spaced apertures extending therethrough, and an annular mounting piece secured centrally about the conduit for securely mounting a pair of air pipes to the opposite ends of the conduit in air-tight engagement therewith. The restrictor plate is maintained in the connector conduit by a swaging operation which causes it to be expanded outwardly into tight engagement with the conduit wall. A pair of tank valves are mounted, by a special saddle, to the mounting piece, and passages are provided through the mounting piece and conduit wall for communication with the interior of the conduit just upstream and downstream of the restrictor plate whereby a differential pressure meter may be connected to the valves to measure the difference in pressure to thereby determine the air flow rate.

Abstract: An exhaust gas recirculation systems directs exhaust gasses from an exhaust manifold to an intake manifold of an internal combustion engine. The exhaust gasses travel from the exhaust manifold, first passing through a flow control valve and then through a measuring orifice before entering the intake manifold. Pressure difference across the orifice is used, along with correction factors based on the pressure difference and pressure downstream of the orifice, to measure and control exhaust gas flow.

Abstract: A modular apparatus for analyzing a fluid includes a disposable fluidic sensor module, a replaceable transducer module, and an expendable electronics package. The disposable fluidic sensor includes a fluidic flowmeter and a capillary structure formed in a plate-like member which receives a sample fluid flow. The fluidic flowmeter is responsive to the fluid flow to generate an output indicative of the flow rate of the fluid, and the capillary structure restricts the fluid flow such that a pressure drop across the capillary structure is related to the viscosity of the fluid. The fluidic flowmeter can be a fluidic oscillator whose oscillation frequency is related to the fluid flow rate. The oscillator flowmeter also serves as an orifice, with the pressure drop across the oscillator being related to the density of the fluid.

Abstract: An exhaust gas recirculation systems directs exhaust gasses from an exhaust manifold to an intake manifold of an internal combustion engine. The exhaust gasses travel from the exhaust manifold, first passing through a flow control valve and then through a measuring orifice before entering the intake manifold. Pressure difference across the orifice is used, along with correction factors based on the pressure difference and pressure downstream of the orifice, to measure and control exhaust gas flow.