Abstract: A mass flowmeter and a method for operating a mass flowmeter is based on the Coriolis principle and incorporates a Coriolis measuring tube, an oscillator associated with and stimulating said Coriolis measuring tube, and a transducer associated with the Coriolis measuring tube and which collects Coriolis forces and/or oscillations based on Coriolis forces. The electric power consumed in the mass flowmeter is controlled as a function of the available electric power. This permits the efficient use of the available electric power, thus permitting the operation of the mass flowmeter via a two wire interface that serves for both the input of electric power and the output of measuring data.

Abstract: A process parameter associated with a material contained in a vibrating structure is estimated. A plurality of motion signals representing motion at a plurality of locations of the vibrating structure are received. The received plurality of motion signals are force filtered with a force filter to produce a force-filtered motion signal that discriminates motion attributable to a force of interest among a plurality of forces acting on the vibrating structure. A process parameter associated with the material contained in the vibrating structure is estimated from the force filtered motion signal. Preferably, a plurality of motion signal values is generated from the received plurality of motion signals, and force filtering includes the step of applying a force filter matrix to the plurality of motion signal values to produce a force filtered motion signal value. A process parameter, such as mass flow, density or the like, is then estimated from the force filtered motion signal value.

Abstract: Motion signals representing motion of a conduit of a mass flowmeter are mode selective filtered to generate a plurality of mode selective filtered motion signals such that the plurality of mode selective filtered motion signals preferentially represent motion associated with a vibrational mode of the conduit. A plurality of time difference estimates is generated from the plurality of mode selective filtered motion signals. A correlation measure is generated from the plurality of time difference estimates. A status of the mass flowmeter system is determined from the generated correlation measure. In some embodiments, the correlation measure comprises an intercept parameter of a scaling function that relates the plurality of time difference estimates to a plurality of reference time differences representing motion of the conduit at a known mass flow. In other embodiments, the correlation measure comprises a correlation coefficient estimated from the plurality of time difference estimates.

Abstract: A capacitive pick off sensor for a mass flow measurement device is disclosed. The mass flow measurement device includes a flow sensor tube and a drive device for vibrating the flow sensor tube. The capacitive pick off sensor includes at least one conductive plate connectable to a first voltage potential and adapted to be situated adjacent the flow sensor tube which is connected to a second voltage potential. The conductive plate is positioned relative to the flow sensor tube so as to define a gap therebetween The capacitance between the conductive plate and the flow sensor tube varies due to the relative motion of the conductive plate and the flow sensor tube when the flow sensor tube is vibrated. In other aspects of the present invention, the flow sensor tube is situated in a housing and the drive device is positioned outside the housing for vibrating the flow sensor tube.

Abstract: A method for testing a Coriolis transducer having a mass adapted vibrate along a vibratory direction in a resonant structure and undergo a displacement along a sensitive axis, perpendicular to the vibration, in response to an angular rate about a mutually perpendicular rate sensing axis. In the absence of an angular rate about the rate sensing axis, forces, FTEST VIBRATORY and FTEST SENSITIVE are applied on the mass along the direction of vibration and along the sensitive axis, respectively, in a predetermined ratio, N. The output VOUT TEST of the transducer is measured in response to the forces, FTEST VIBRATORY and FTEST SENSITIVE.

Abstract: A Coriolis mass flow sensor includes a flow sensor tube, a drive device situated relative to the flow sensor tube so as to cause the flow sensor tube to vibrate, and capacitance displacement gauges situated relative to the flow sensor tube so as to measure the twist in the flow sensor tube due to Coriolis force. In specific embodiments, electromagnetic, electrostatic, acoustic, and/or piezoelectric drives are used to vibrate the flow sensor tube. In still further embodiments, piezoelectric devices are used both to vibrate the flow sensor tube and measure the twist in the flow sensor tube. In accordance with certain embodiments of the invention, the Coriolis mass flow controller further includes an integrated flow control device adapted to receive fluid from the flow sensor tube and provide flow control.

Abstract: A Coriolis flowmeter is operated to generate accurate output material flow information over a wide temperature range that includes cryogenic temperatures. Heretofore, temperature compensation was provided using linear expressions that erroneously assumed the value of Young's Modulus E varied linearly with temperature. This resulted in unacceptable output information errors. The Coriolis flowmeter of the present invention uses non-linear compensation information stored in memory to generate accurate non-linear temperature compensated material flow output information at all temperatures including cryogenic temperatures. In one embodiment, the stored non-linear information represents measured values of Young's Modulus E that are used to generate accurate temperature compensated material flow output information.

Abstract: A method for testing a Coriolis transducer having a mass adapted vibrate along a vibratory direction in a resonant structure and undergo a displacement along a sensitive axis, perpendicular to the vibration, in response to an angular rate about a mutually perpendicular rate sensing axis. In the absence of an angular rate about the rate sensing axis, forces, FTEST VIBRATORY and FTEST SENSITIVE, are applied on the mass along the direction of vibration and along the sensitive axis, respectively, in a predetermined ratio, N. The output VOUT TEST of the transducer is measured in response to the forces, FTEST VIBRATORY and FTEST SENSITIVE.

Abstract: A process for activating an oscillator serving to oscillate a Coriolis line of a Coriolis mass flowmeter for moving fluids, and of a power supply circuit system for an oscillator of a mass flowmeter for moving fluids operating by the Coriolis principle. The oscillator is supplied a pulse-width-modulated pulsed sinusoidal signal. The resulting heat-loss reduction in an amplifier circuit leads to a better utilization of the energy available for supplying the oscillator.

Abstract: A digital flowmeter includes a vibratable conduit, a driver connected to the conduit and operable to impart motion to the conduit, and a sensor connected to the conduit and operable to sense the motion of the conduit. A control and measurement system is connected to the driver and the sensor. The control and measurement system includes circuitry to receive a sensor signal from the sensor, generate a drive signal based on the sensor signal using digital signal processing, supply the drive signal to the driver, and generate a measurement of a property of a two-phase material flowing through the conduit based on the signal from the sensor.

Abstract: 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.

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 initializing parameters in a drive circuit. This invention applies initial drive signals to a drive circuit which causes said flow tube to vibrate. The configuration of the flow tube is then determined from pick-off signals received from pick-off sensors associated with the flow tube. Parameters for generation of said drive signals are then set based upon the configuration of said flow tube.

Abstract: A method of correcting the phase difference between first and second data signals from a Coriolis flowmeter using three parallel input stages which process the signals and a pair of phase detectors for receiving the signals by delivering the first and second signals continuously to first and second input stages, respectively, to produce processed data signals therefrom while delivering the first and second signals alternately to the third input stage to produce a processed data signal therefrom, routing the processed data signals to at least one additional phase detector to produce first and second corrective phase differences, and producing a corrected phase difference by summing the uncorrected phase difference and the difference between the first and second corrective phase differences. A circuit for carrying out the method is also disclosed.

Abstract: A flowmeter and a method of determining the mass flow rate. The flowmeter has a first measuring tube and a second measuring tube which are arranged in a common housing and are connected to one another mechanically. Also provided are an excitation device for exciting the measuring tubes to oscillation, and a detector device for detecting oscillation parameters which is connected to an evaluating device, which determines a mass flow rate signal for each measuring tube from output signals from the detector device. The object is to improve the measuring accuracy in cases in which identical conditions do not prevail in the measuring tubes. For that purpose, an amplitude detecting device is provided which detects the amplitude of the oscillation of each measuring tube, and a correcting device is connected to the evaluating device, which correcting device has a flow input and an amplitude input for each measuring tube.

Abstract: A process parameter such as mass flow is determined in a vibrating conduit process parameter sensor using a complex modal transformation estimated from a plurality of motion signals representing motion of the parameter sensor conduit. According to an aspect of the invention, a complex eigenvector is provided representing motion of the conduit at the plurality of locations at a known mass flow. A plurality of motion signals is received from a plurality of motion transducers, the plurality of motion signals indicating motion at a plurality of locations on the conduit as a material flows through the conduit. A complex modal transformation relating the received plurality of motion signals to the complex eigenvector is estimated. Mass flow through the conduit is estimated from the known mass flow and the estimated complex modal transformation. Related apparatus and computer program products are also discussed.

Abstract: A fluid property monitor includes a transducer assembly to impart multiple frequency energy to a conduit in one or more modes and to receive resonant frequency energy from the conduit. The resonant frequency energy is responsive to the imparted energy, the conduit and a fluid in the conduit. The fluid property monitor can also be defined as including: a frequency signal generator connected to cause multiple frequency energy to be transferred to a conduit having a fluid to be monitored; and a spectral analysis signal processor connected to receive and process electrical signals generated in response to vibrations propagated through the conduit and the fluid in the conduit in response to transferred multiple frequency energy. Particular implementations can be adapted as a densitometer, a coherent flow detector, and other particular fluid parameter detectors.

Abstract: The accuracy of this method is comparable to that of the measurement of liquids. The fluid flows through at least one flow tube (4) of a mass flow sensor (1) of a Coriolis mass flow/density meter, which flow tube vibrates at a frequency f being equal to or in the vicinity of the instantaneous mechanical resonance frequency of the flow tube (4) having a vibrator (16). A first and second vibration sensor (17, 18) are attached to the flow tube, deliver a first and a second sensor signal (x17, x18), and are positioned at a given distance from each other in the direction of flow. The flow tube (4) is surrounded by a support frame or a support tube (15) or held by a support plate so as to be capable of vibrating. The sensor signals (x17, x18) have a phase difference from which a signal qf is formed; it is multiplied by a function f(c) dependent on the speed of sound c in the fluid which can be approximated by a function f(Tm) dependent on the current temperature Tm of the flow tube (4).

Abstract: This circuit is suitable for flow tubes (4) the vibration frequency of which is in the order of 1 kHz. A fluid to be measured flows through the tube (4) vibrating in operation at a frequency determined by the density of the fluid. Attached to the tube (4) are electromagnetic vibration sensors (17, 18) positioned at a given distance from each other delivering sinusoidal sensor signals (x17, x18). Impedance-matching devices (31, 32) are fed by the sensor signals. Inputs of an intermediate switch (35) are connected to the outputs of impedance-matching devices. Additional impedance-matching device (33, 34) are fed by outputs of the intermediate switch. Low-pass filters (37, 38) are connected to the outputs of the additional impedance matching devices. The upper cutoff frequency of low-pass filter (37) differs by about 10% to 15% from the upper cutoff frequency of low-pass filter (38). Zero-crossing detector (39, 40) are fed by the outputs of the low-pass filters.

Abstract: A drive system is taught for controlling the modal content of any number of drive signals used to excite any number of drives on a vibrating conduit such as is found in a Coriolis mass flowmeter or a vibrating tube densimeter. One or more motion signals are obtained from one or more spatially distinct feedback sensors. The motion signals are preferably filtered using a multi-channel modal filter to decompose the motion signals, each of which contain modal content at a plurality of vibration modes, into n single degree of freedom modal response signals. Each modal response signal corresponds to one of the vibration modes at which the vibrating conduit is excited. The n modal response signals are input to a drive channel having a separate processing channel for each of the n modal response signals.

Abstract: A self-characterizing vibrating conduit sensor for measuring a process parameter in a material processing system includes a conduit configured to contain material from the material processing system and a plurality of motion transducers operative to produce a plurality of motion signals representing motion at a plurality of locations on the conduit. A modal parameter estimator is configured to receive the plurality of motion signals and operative to estimate a modal parameter from the received plurality of motion signals. The modal parameter, e.g., a modal filter parameter or a force projection parameter, relates behavior of the conduit to behavior of a single degree of freedom (SDOF) system. A process parameter estimator is configured to receive the plurality of motion signals, responsive to the modal parameter estimator and operative to estimate a process parameter associated with a material in the conduit from the received plurality of motion signals according to the estimated modal parameter.

Abstract: In a coriolis flow meter, two drivers are provided and a measure of mass flow rate derived from the adjustment of the input signals to each driver required to achieve a desired phase shift in the output. This may give higher accuracy compared to conventional meters in which the phase shift is simply measured, and may also enable determination of other characteristics of the fluid.

Abstract: A Coriolis flowmeter is operable as a vibrating tube densitometer where a flowtube is driven to vibrate at a fundamental frequency from which density of the material flowing through the flowtube may be calculated. The drive gain is monitored as an indicator of multiphase flow including gas and liquid components where a substantial increase in drive gain indicates gas damping of the flowtube vibrations due to a transient bubble entering the flowtube. The gas damping effects of the transient bubble and the correspondingly reduced density readings are remediated by the use of historical density measurements corresponding to periods of flow when no transient bubble has entered the flowtube.

Abstract: 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.

Abstract: The invention relates to a closed system. It consists of a spirally-wound elastic pipe (1), inside which a fluid flows, and a straight rubber pipe (2) extending in the center of the spiral, inside which pipe the fluid is so arranged as to flow in the opposite direction, i.e. the fluid circulates inside a closed circuit formed in this way. The system is so arranged as to be extended and compressed so that the internal forces therein enter into a state of imbalance during the actual extension and compression process, and so that the system is thereby so arranged as to begin to move because of the internal forces, which can be utilized as an energy source.

Abstract: A system for initializing parameters of a transmitter connected to a Coriolis flowmeter. This invention applies initial drive signals to a drive circuit which causes a flow tube to vibrate. The type of the flow tube is then determined from signals received from pick-off sensors associated with the flow tube. Parameters for generation of said drive signals are then set based upon the type of said flow tube.

Abstract: A digital flowmeter includes a vibratable conduit, a driver connected to the conduit and operable to impart motion to the conduit, and a sensor connected to the conduit and operable to sense the motion of the conduit. A control and measurement system is connected between the driver and the sensor. The control and measurement system includes circuitry to receive a sensor signal from the sensor, generate a drive signal based on the sensor signal using digital signal processing, supply the drive signal to the driver, and generate a measurement of a property of material flowing through the conduit based on the signal from the sensor.

Abstract: Method and apparatus are provided for determining pressure using a non-intrusive sensor that is easily attachable to the plumbing of a pressurized system. A bent mode implementation and a hoop mode implementation of the invention are disclosed. Each of these implementations is able to non-intrusively measure pressure while fluid is flowing. As well, each implementation may be used to measure mass flow rate simultaneously with pressure. An ultra low noise control system is provided for making pressure measurements during gas flow. The control system includes two tunable digital bandpass filters with center frequencies that are responsive to a clock frequency. The clock frequency is divided by a factor of N to produce a driving vibrational signal for resonating a metal sensor section.

Abstract: In an electromagnetic flowmeter, the conventional derivation of flow velocity is corrected or replaced by an alternative calculation to take into account estimated non-linear dependence of field strength produced by the coil with applied coil current. This can be used to enable more accurate measurement, over a wider range of coil current. The improved accuracy allows the coil current to be adjusted to optimise power consumption; the adjustment of coil current in this manner is another aspect of the invention.

Abstract: A plurality of motion signals is received representing motion at a plurality of locations of a vibrating conduit containing material. The received plurality of motion signals is processed to resolve the motion into a plurality of real normal modal components. A process parameter is estimated from a real normal modal component of the plurality of real normal modal components. According to one aspect, the motion signals may be processed by applying a mode pass filter to produce an output that preferentially represents a component of the motion associated with a real normal mode of the vibrating conduit. A process parameter may be estimated from the filtered output using, for example, conventional phase difference techniques. According to another aspect, real normal modal motion is estimated from the received plurality of motion signals, and a process parameter is estimated from the estimated real normal modal motion.

Abstract: A process parameter sensor for a material processing system includes a conduit configured to contain material from the material processing system. A plurality of motion transducers is operative to produce a plurality of motion signals representing motion at a number of locations on the conduit. An overdetermined process parameter estimator is responsive to the plurality of motion transducers and configured to receive the plurality of motion signals. The overdetermined process parameter estimator is operative to resolve conduit motion into motion attributable to each of a predetermined number of forces and to estimate a process parameter associated with a material in the conduit according to the resolved motion, wherein the number of locations exceeds the number of forces such that the plurality of motion signals provides an overdetermined information set for resolution of conduit motion into motion attributable to the predetermined number of forces.

Abstract: An oscillatory vibration driver is operably connected to a Coriolis flowmeter for use in vibrating the meter flow tubes. The meter electronics contain a mimetic circuit that permits use of the driver as a signal pickoff which provides a measurement of back electromotive force for use in calculating mass flow rate and density from the Coriolis flowmeter. The mimetic circuit contains an analog coil and magnet that facilitate the measurement of back electromotive force, or the mimetic circuit may comprise digital means.

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 drive system for a vibrating tube-based measurement instrument employing a spatial filter to produce a drive signal having modal content only at a desired vibration mode. Multiple feedback sensors located at different locations along a vibrating tube produce multiple feedback sensors. Each feedback signal has applied to it a weighting or gain factor. All of the weighted feedback signals are then summed to produce a drive signal, or a signal proportional to a drive signal, having improved modal content as compared to any of the feedback signals by themselves. The weighting factors are selected by any of several means. One method is to build the eigenvector matrix for the vibrating flow tube by extracting the eigenvectors from a finite element model of the vibrating structure. The inverse or psuedo-inverse of the eigenvector matrix is calculated to obtain the modal filter vector. The appropriate set of weighting coefficients are selected from the modal filter vector.