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

Apparatus and accompanying methods for use therein for a Coriolis mass flow rate meter which is substantially immune to noise, and more particularly, to such a meter that is substantially unaffected by noise that occurs at substantially any frequency different from a fundamental frequency at which the flow tube(s) in the meter vibrate Specifically, the meter relies on measuring mass flow rate by determining the phase difference that occurs between real and imaginary components of the discrete fourier transform (DFT) of both the left and right velocity sensor waveforms evaluated at the fundamental frequency at which the flow tubes vibrate The fundamental frequency is located, during an initialization operation, by providing a power spectrum, determined through use of the DFT, of one of the sensor signals and then selecting that frequency at which the magnitude of the power spectrum reaches a maximum value In addition, the frequency at which both velocity sensor signals is sampled is readjusted in response to any change in the phase of one of the velocity sensor signals, as transformed using the DFT, in order to assure that the sampling frequency always remains substantially equal to a pre-defined integer multiple of the fundamental frequency Furthermore, the meter, through use of the numerical value of any such phase change, also provides a density indication which is also substantially immune to such noise

Coriolis mass flow rate meter having a substantially increased noise immunity

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 flowmeter is disclosed. The flowmeter includes a vibratable conduit, and a driver connected to the conduit that is operable to impart motion to the conduit. A sensor is connected to the conduit and is operable to sense the motion of the conduit and generate a sensor signal. A controller is connected to receive the sensor signal. The controller is operable to detect a single-phase flow condition and process the sensor signal using a first process during the single-phase flow condition to generate a validated mass-flow measurement. The controller is also operable to detect a two-phase flow condition and process the sensor signal using a second process during the two-phase flow condition to generate the validated mass-flow measurement.

Correcting for two-phase flow in a digital flowmeter

We present the first mass-flow sensor in silicon, based on the Coriolis-force principle. The sensor consists of a double-loop tube resonator structure with a size of only 9/spl times/18/spl times/1 mm. The tube structure is excited electrostatically into a resonance-bending or torsion vibration mode. A liquid mass flow passing through the tube induces a Coriolis force, resulting in a twisting angular motion phase shifted and perpendicular to the excitation. The excitation and Coriolis-induced angular motion are detected optically. The amplitude of the induced angular motion is linearly proportional to the mass flow and, thus, a measure thereof. The sensor can be used for measurement of fluid density since the resonance frequency of the sensor is a function of the fluid density. The measurements show the device to be a true mass-flow sensor with direction sensitivity and high linearity in the investigated flow range of as low as 0-0.5 g/s in either direction. A sensitivity of 2.95 (mV/V)/(g/s) and standard deviation for the measured values of 0.012 mV/V are demonstrated.

A silicon resonant sensor structure for Coriolis mass-flow measurements

A flow meter apparatus for measuring the mass flow rates of fluids passed through two essentially parallel, cantilever mounted U-shaped flow tubes where, instead of the fluid serially passing through one of the U-shaped flow tubes and then through the second U-shaped flow tube, the fluid is essentially evenly divided and half of the fluid is passed through one U-shaped flow tube and the other half of the fluid is passed through the other U-shaped flow tube. The two U-shaped flow tubes are sinusoidally driven as the tines of a tuning fork, and when a fluid is passed through the oscillating U-shaped flow tubes Coriolis forces are generated which torsionally deflect the U-shaped flow tubes. Such torsional deflections are a function of the mass flow rate of the fluid passing through the two U-shaped flow tubes.

Ronald Reed Longmont Colorado Us Cage

Papers

Parallel path Coriolis mass flow rate meter