A Coriolis mass flowmeter having at least one curved measuring tube having an inlet end, outlet end and a central curved section between the inlet end and outlet end, a carrier bridge extending between the inlet end and outlet end of the measuring tube and fixing the measuring tube ends, at least one oscillation generator attached to the measuring tube, at least one oscillation sensor for detecting measuring tube oscillations, an evaluation unit for evaluating detected measuring tube oscillations, and wherein the measuring tube extends through at least one opening from an inner area of the carrier bridge out of the carrier bridge into the outer area of the carrier bridge, the central curved section running outside of the carrier bridge. A conductor guiding structure is arranged on the carrier bridge extending toward the oscillation sensor and the conductor arrangement fixed on the conductor guiding structure.

Coriolis mass flowmeter

At least one parameter of at least one fluid in a pipe (12) is measured using a spatial array of acoustic pressure sensors (14, 16, 18) placed at predetermined axial locations x1,x2,x3 along the pipe (12). The pressure sensors (14, 16, 18) provide acoustic pressure signals P1(t), P2(t), P3(t) on lines (20, 22, 24) which are provided to signal processing logic (60) which determines the speed of sound amix of the fluid (or mixture) in the pipe (12) using acoustic spatial array signal processing techniques with the direction of propagation of the acoustic signals along the longitudinal axis of the pipe (12). Numerous spatial array processing techniques may be employed to determined the speed of sound amix. The speed of sound amix is provided to logic (48) which calculates the percent composition of the mixture, e.g., water fraction, or any other parameter of the mixture or fluid which is related to the sound speed amix. The logic (60) may also determine the mach number (MX) of the fluid. The acoustic pressure signals P1(t), P2(t), P3(t) measured are lower frequency (and longer wavelength) signals than those used for ultrasonic flow meters, and thus is more tolerant to inhomogeneities in the flow. No external source is required and thus may operate using passive listening. The invention will work with arbitrary sensor spacing and with as few as two sensors if certain information is known about the acoustic properties of the system.

Fluid parameter measurement in pipes using acoustic pressures

https://www.repository.cam.ac.uk/bitstream/handle/1810/246007/Coriolis-draft-paper-V8.1-FMI-Larger-Fonts.pdf?sequence=1

Coriolis flowmeters: a review of developments over the past 20 years, and an assessment of the state of the art and likely future directions

A multiphase flow meter distributed system is disclosed that is capable of measuring phase flow rates of a multiphase fluid. The distributed system includes at least one flow meter disposed along the pipe, an additional sensor disposed along the pipe spatially removed from the flow meter, and a multiphase flow model that receives flow related parameters from the flow meter and the additional sensor to calculate the phase flow rates. The flow meter provides parameters such as pressure, temperature, fluid sound speed and/or velocity of the fluid, and the additional sensor provides a parameter indicative of pressure and or temperature of the fluid. Depending on production needs and the reservoir dimensions, the distributed system may utilize a plurality of flow meters disposed at several locations along the pipe and may further include a plurality of additional sensors as well. The distributed system preferably uses fiber optic sensors with bragg gratings. This enables the system to have a high tolerance for long term exposure to harsh temperature environments and also provides the advantage of multiplexing the flow meters and/or sensors together.

Distributed sound speed measurements for multiphase flow measurement

An apparatus for non-intrusively sensing fluid flow within a pipe is provided. The apparatus includes a first sensing array for sensing acoustic signals traveling at the speed of sound through fluid flow within the pipe, a second sensing array for sensing local pressure variations traveling with the fluid flow, and a housing attached to the pipe for enclosing the sensing arrays. The first sensing array includes a plurality of first optical pressure sensors and the second sensing array includes a plurality of second optical pressure sensors.

Apparatus for sensing fluid in a pipe

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 apparati 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. Accordingly, an apparatus for measuring a mass flow rate of a fluid flowing relative to a flow conduit includes: (1) a force driver for vibrating the flow conduit; (2) a sensor for measuring a resulting motion of the flow conduit and producing a sensed motion signal indicative thereof, the resulting motion containing a Coriolis mode component and a boundary condition mode component; (3) signal processing circuitry, coupled to the sensor to receive the sensed motion signal therefrom, for determining a magnitude of the Coriolis mode component of the resulting motion; and (4) output circuitry for producing an output signal proportional to the mass flow rate, the output signal substantially free of influence from the boundary condition mode component of the sensed motion signal.

Signal processing apparati and methods for attenuating shifts in zero intercept attributable to a changing boundary condition in a coriolis mass flow meter

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

Signal processing and field proving methods and circuits for a coriolis mass flow meter

An example fluid parameter sensor and meter is disclosed to measure at least one parameter of a fluid. In an example, the fluid parameter meter includes an outer conduit. A sensor element assembly is disposed in the outer conduit and has at least one straight uniform sensor element with an open interior to convey the fluid inside of the sensor element assembly. At least one mounting flexure is fixedly attached to the sensor element assembly and to the outer conduit. The at least one mounting flexure is configured to enable the sensor element assembly to vibrate in a natural radial mode shape of vibration. At least one vibration driver causes the sensor element assembly to vibrate. At least one vibration sensor senses the vibration of the sensor element assembly.

Fluid parameter sensor and meter

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.

System and method for employing an imaginary difference signal component to compensate for boundary condition effects on a coriolis mass flow meter

An ionization gauge that measures pressure has an electron source that emits electrons, and an anode that defines an ionization space. The gauge also includes a collector electrode to collect ions formed by an impact between the electrons and a gas and to measure pressure based on the collected ions. The electron source is dynamically varied in emission current between a plurality of emission levels dependent on pressure and a second parameter other than pressure. The ionization gauge may also vary various operating parameters of the gauge components according to parameters stored in a non-volatile memory and selected by a user.

Michael N. Schott

Papers

Signal processing apparati and methods for attenuating shifts in zero intercept attributable to a changing boundary condition in a coriolis mass flow meter

Signal processing and field proving methods and circuits for a coriolis mass flow meter

Fluid parameter sensor and meter

System and method for employing an imaginary difference signal component to compensate for boundary condition effects on a coriolis mass flow meter

Ionization gauge with emission current and bias potential control