Abstract: A Coriolis mass flowmeter which comprises at least first and second generally parallel flowtubes, each of which includes a first half that is connected to an inlet manifold and a second half that is connected to an outlet manifold, a first brace bar which is attached to the first halves of the flowtubes, and a second brace bar which is attached to the second halves of the flowtubes. The first and second brace bars are oriented on the flowtubes such that, when the flowtubes are vibrated in at least one of a driven mode of vibration and a Coriolis mode of vibration, the resulting reaction forces at the inlet and outlet manifolds are less than those that exist when the first and second brace bars are oriented generally perpendicular to the flowtubes.

Abstract: A Coriolis mass flowmeter having a flowtube and excitation circuitry, coupled to the flowtube, that can excite the flowtube at varying frequencies of vibration and a method of operating the same to compensate for effects of fluid compressibility. In one embodiment, the Coriolis mass flowmeter includes: (1) flowrate measurement circuitry, coupled to the flowtube, that measures a first mass flowrate of a fluid flowing through the flowtube at a first vibration frequency and a second mass flowrate of the fluid at a second vibration frequency and (2) fluid compressibility compensation circuitry, coupled to the flowrate measurement circuitry, that employs the first and second mass flowrates to determine a frequency response of the fluid and a fluid compressibility compensation adjustment from the frequency response.

Abstract: A system for, and method of, compensating for a boundary condition effect on a Coriolis meter having (at least) two sensors for generating preliminary signals that are a function of fluid flow through the meter and a Coriolis meter employing the system or the method. In one embodiment, the system includes: (1) signal combination circuitry, couplable to the (at least) two sensors, that develops an imaginary difference signal based on the preliminary signals and (2) boundary effect compensation circuitry, coupled to the signal combination circuitry, that calculates a boundary effect compensation factor based on the imaginary difference signal.

Abstract: A signal processing apparatus and method for measuring a mass flow rate of a fluid flowing in conjunction with a surface of a Coriolis mass flow meter and a field-provable Coriolis mass flow meter. The apparatus includes: (1) a driver for creating a prescribed vibration in the surface, (2) a motion sensor for measuring a motion of the surface, (3) response characteristic determination circuitry, coupled to the motion sensor, for determining a response characteristic of the surface and (4) flow rate calculation circuitry, coupled to the response characteristic determination circuitry, for calculating a measured mass flow rate of the fluid as a function of the motion and the response characteristic. The field-provable meter employs the response characteristic to monitor or compare meter performance without requiring a separate proving device.

Abstract: In the field of Coriolis mass flow meters, determination of the true zero of the meter has always been problematic due to zero drift effects with changing boundary conditions and fluid parameters. Disclosed are apparatus and methods for determining the true mass flow related component of the signal of the meter separately from errors caused by changing boundary conditions and fluid parameters.

Abstract: A method of compensating for at least one of pressure and density with a Coriolis meter, the meter having two modes of vibration impressed thereon, a fluid in the meter altering the modes of vibration to produce altered modes of vibration. The method includes the steps of: (1) measuring both the altered modes of vibration with a detector circuit at a selected working point and (2) simultaneously solving for the at least one of pressure and density, the at least one of pressure and density directly determined thereby to allow resulting flow-related signals produced by the meter substantially insensitive to a change in the at least one of pressure and density.

Abstract: A flow meter apparatus for measuring attributes of a fluid using the Coriolis principle is disclosed. The apparatus comprises (1) a body capable of being inserted into and surrounded by the fluid, (2) an actuator, disposed within the body, for vibrating a surface of the body in a radial mode of vibration, the vibrating surface developing Coriolis forces within the fluid, (3) a detector, coupled to the surface, for measuring motion of the surface, the motion being a function of Coriolis forces developed in the fluid and (4) a circuit, coupled to the measuring detector, for determining an attribute of the fluid as a function of the motion of the surface. In a preferred embodiment of the invention, a conduit surrounds the apparatus and is coupled to the detector. The apparatus allows precise detection of mass flow rate, pressure, density and viscosity of the fluid surrounding the apparatus.

Abstract: Several Radial Mode Coriolis mass flow rate meter geometries and electronic circuits are described that may be made to be sensitive to pressure or density changes. In one embodiment, the meter comprises: (1) a flow conduit for containing a fluid having a physical characteristic, the fluid adapted to flow in the conduit at an unknown rate, (2) a drive circuit for creating a vibration in the flow conduit, the fluid altering the vibration as a function of the physical characteristic and the flow rate, (3) a detector circuit for measuring the altered vibration at a working point and producing a signal representing an uncompensated mass flow rate of the fluid and (4) a computation circuit for calculating a compensated mass flow rate of the fluid proportional to the uncompensated rate by 1/.OMEGA.1.sup.n, where .OMEGA.1 is a driven natural frequency of the flow conduit and n is a number chosen as a function of the working point, the compensated rate thereby reduced of effects of the physical characteristic.

Abstract: Several Radial Mode Coriolis mass flow rate meter geometries and electronic circuits are described that may be made to be sensitive to pressure or density changes. In one embodiment, the meter comprises: (1) a flow conduit for containing a fluid having a physical characteristic, the fluid adapted to flow in the conduit at an unknown rate, (2) a drive circuit for creating a vibration in the flow conduit, the fluid altering the vibration as a function of the physical characteristic and the flow rate, (3) a detector circuit for measuring the altered vibration at a working point and producing a signal representing an uncompensated mass flow rate of the fluid and (4) a computation circuit for calculating a compensated mass flow rate of the fluid proportional to the uncompensated rate by 1/.OMEGA.1.sup.n, where .OMEGA.1 is a driven natural frequency of the flow conduit and n is a number chosen as a function of the working point, the compensated rate thereby reduced of effects of the physical characteristic.

Abstract: A flow meter apparatus for measuring attributes of a fluid using the Coriolis principle is disclosed. The apparatus comprises (1) a body capable of being inserted into and surrounded by the fluid, (2) an actuator, disposed within the body, for vibrating a surface of the body in a radial mode of vibration, the vibrating surface developing Coriolis forces within the fluid, (3) a detector, coupled to the surface, for measuring motion of the surface, the motion being a function of Coriolis forces developed in the fluid and (4) a circuit, coupled to the measuring detector, for determining an attribute of the fluid as a function of the motion of the surface. In a preferred embodiment of the invention, a conduit surrounds the apparatus and is coupled to the detector. The apparatus allows precise detection of mass flow rate, pressure, density and viscosity of the fluid surrounding the apparatus.

Abstract: A flow meter apparatus for measuring the mass flow rate of a fluid using the Coriolis principle. A single straight flow conduit is employed which is vibrated in a radial-mode of vibration. Coriolis forces are thereby produced along the walls of the flow conduit which deform the conduit's cross-sectional shape as a function of mass flow rate. Additional embodiments are disclosed employing vibration of selected portions of the flow conduit walls. In addition, a method is described to determine the pressure and the density of a fluid by simultaneously vibrating a flow conduit in two modes of vibration and thereby determining pressure and density based on changes in each frequency.