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5526685 Fluid flow rate measuring and controlling apparatus and method for using same
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5526685 FLUID FLOW RATE MEASURING AND CONTROLLING APPARATUS AND METHOD FOR USING SAME Davis Homer Atlanta, GA, UNITED STATES assigned to Graseby Andersen Inc A volumetric flow control apparatus and method for measuring and controlling the volumetric flow rate and flow volume of a fluid. The apparatus comprises a reciprocating diaphragm meter having a diaphragm mounted for reciprocating movement and a diaphragm position indicator assembly for monitoring the position of the diaphragm as it reciprocates. As a fluid under pressure passes through the reciprocating diaphragm meter the diaphragm reciprocates through at least one meter cycle during which the meter passes a fixed volume of fluid per meter cycle. A timer responsive to the diaphragm position indicator is provided to measure the elapsed time for the meter diaphragm to reciprocate through at least one meter cycle. A processor calculates the volume flow rate of the fluid passing through the reciprocating diaphragm meter by dividing the fixed volume of fluid passed by the meter in a meter cycle by the elapsed time measured during the meter cycle. The volume flow rate of fluid passing through the reciprocating diaphragm meter is controlled by a controller which compares the measured flow rate to a desired flow rate and then causes the pressure differential across the reciprocating diaphragm meter to be changed to increase or decrease the fluid flow rate.
5526698 CAPACITANCE TYPE ELECTROMAGNETIC FLOWMETER Sakurai Yutak; lshihara assigned to Hitachi Ltd
Tami
Katsuta,
JAPAN
A capacitance type electromagnetic flowmeter whose output is relatively free from fluctuations caused by external vibrations has a flow tube supported in a casing member by means of members having elasticity and viscosity (eg, O-rings). Magnetic parts such as coils and a core are fixed to the casing member so as to define a space therewith, and protective rings are kept liquid-tight with respect to the flow tube by O-rings interposed therebetween. The equivalent mass of the flowmeter section vibrating integrally with the flow tube is reduced to increase the resonance frequency. Further, since the flow tube is insulated from vibrations of the protective
rings,, the flow is less subject to vibrations, decreasing fluctuations in output due to vibrations.
thereby external
5526699 ULTRASONIC GAS FLOW MEASUREMENT METHOD AND APPARATUS Dorr John A Crofton, MD, UNITED STATES to Xecutek Corporation
assigned
PCT No. PCT/US92/06180 Sec. 371 Date Jan. 28, 1994 Sec. 102(e) Date Jan. 28, 1994 PCT Filed Jul. 29, 1992 PCT Pub. No. WO93/03334 PCT Pub. Date Feb. 18, 1993. A transit time gas flow meter comprising a pair of transducers mounted at an oblique angle to a gas flow in a duct for measuring transit time of an ultrasonic pulse in both directions between the transducers and a computer to determine the difference between transit times as a measure of the velocity of a gas stream flowing in the duct. Each transducer is carried in a mounting assembly which is comprised of a U-shaped frame member having a base and leg members and an ultrasonic reflection surface formed on the base of a U-shaped frame member. A transducer is mounted between said legs and at a reference target carried on the U-shaped frame member and is positioned at the edge of the gas, and the ultrasonic transit time to each said reference target is subtracted by the computer means from the transit times from each transducer to the other transducer, to zero flow calibrate the transit time flow meter and to improve the accuracy measurement.
5530639 BRIDGE PULSE CONTROLLED CONSTANT CURRENT DRIVER FOR MAGNETIC FLOWMETER Schulz Robert K; Pro John D Plymouth, STATES assigned to Rosemount Inc
MN, UNITED
A magnetic flowmeter system provides a volumetric flow rate output and has a coil receiving a magnetic field producing coil current from the current supply circuitry. The current supply circuitry includes an H-bridge transistor circuit having first and second switches which couple one of the first and second coil wires to a supply conductor. Third and fourth switches of the bridge circuit couple the other of the first and second coil wires to a
5526685 FLUID FLOW RATE MEASURING AND CONTROLLING APPARATUS AND METHOD FOR USING SAME Davis Homer Atlanta, GA, UNITED STATES assigned to Graseby Andersen Inc A volumetric flow control apparatus and method for measuring and controlling the volumetric flow rate and flow volume of a fluid. The apparatus comprises a reciprocating diaphragm meter having a diaphragm mounted for reciprocating movement and a diaphragm position indicator assembly for monitoring the position of the diaphragm as it reciprocates. As a fluid under pressure passes through the reciprocating diaphragm meter the diaphragm reciprocates through at least one meter cycle during which the meter passes a fixed volume of fluid per meter cycle. A timer responsive to the diaphragm position indicator is provided to measure the elapsed time for the meter diaphragm to reciprocate through at least one meter cycle. A processor calculates the volume flow rate of the fluid passing through the reciprocating diaphragm meter by dividing the fixed volume of fluid passed by the meter in a meter cycle by the elapsed time measured during the meter cycle. The volume flow rate of fluid passing through the reciprocating diaphragm meter is controlled by a controller which compares the measured flow rate to a desired flow rate and then causes the pressure differential across the reciprocating diaphragm meter to be changed to increase or decrease the fluid flow rate.
5526698 CAPACITANCE TYPE ELECTROMAGNETIC FLOWMETER Sakurai Yutak; lshihara assigned to Hitachi Ltd
Tami
Katsuta,
JAPAN
A capacitance type electromagnetic flowmeter whose output is relatively free from fluctuations caused by external vibrations has a flow tube supported in a casing member by means of members having elasticity and viscosity (eg, O-rings). Magnetic parts such as coils and a core are fixed to the casing member so as to define a space therewith, and protective rings are kept liquid-tight with respect to the flow tube by O-rings interposed therebetween. The equivalent mass of the flowmeter section vibrating integrally with the flow tube is reduced to increase the resonance frequency. Further, since the flow tube is insulated from vibrations of the protective
rings,, the flow is less subject to vibrations, decreasing fluctuations in output due to vibrations.
thereby external
5526699 ULTRASONIC GAS FLOW MEASUREMENT METHOD AND APPARATUS Dorr John A Crofton, MD, UNITED STATES to Xecutek Corporation
assigned
PCT No. PCT/US92/06180 Sec. 371 Date Jan. 28, 1994 Sec. 102(e) Date Jan. 28, 1994 PCT Filed Jul. 29, 1992 PCT Pub. No. WO93/03334 PCT Pub. Date Feb. 18, 1993. A transit time gas flow meter comprising a pair of transducers mounted at an oblique angle to a gas flow in a duct for measuring transit time of an ultrasonic pulse in both directions between the transducers and a computer to determine the difference between transit times as a measure of the velocity of a gas stream flowing in the duct. Each transducer is carried in a mounting assembly which is comprised of a U-shaped frame member having a base and leg members and an ultrasonic reflection surface formed on the base of a U-shaped frame member. A transducer is mounted between said legs and at a reference target carried on the U-shaped frame member and is positioned at the edge of the gas, and the ultrasonic transit time to each said reference target is subtracted by the computer means from the transit times from each transducer to the other transducer, to zero flow calibrate the transit time flow meter and to improve the accuracy measurement.
5530639 BRIDGE PULSE CONTROLLED CONSTANT CURRENT DRIVER FOR MAGNETIC FLOWMETER Schulz Robert K; Pro John D Plymouth, STATES assigned to Rosemount Inc
MN, UNITED
A magnetic flowmeter system provides a volumetric flow rate output and has a coil receiving a magnetic field producing coil current from the current supply circuitry. The current supply circuitry includes an H-bridge transistor circuit having first and second switches which couple one of the first and second coil wires to a supply conductor. Third and fourth switches of the bridge circuit couple the other of the first and second coil wires to a