Krohne Messtechnik Gmbh

Krohne Ag

Kourosh Kolahi

Ralf Storm

Andreas Poremba

Johannes Kunze

Thorsten Schröder

A method for operating a Coriolis mass flowmeter in which the interferences when calculating the medium parameters is considered by the eigenfrequency (f) of the oscillation of the measuring tube being determined in the first and second natural modes during operation of the Coriolis mass flowmeter, and at least one medium parameter ({dot over (m)}) is calculated with the aid of the oscillation measuring variable (&#x394;t) by means of a calculation rule representing a mathematic relation between the oscillation measuring variable (&#x394;t), the medium parameter ({dot over (m)}) and the eigenfrequencies (f, f) of the oscillations of the measuring tube in the first natural mode and the second natural mode, and the medium parameter ({dot over (m)}) being determined taking into consideration the current determined eigenfrequencies (f, f) of the oscillations of the measuring tub in the first natural mode and the second natural mode as well as the oscillation measuring variable (&#x394;t).

Method for operating a Coriolis mass flowmeter

A method for operating a Coriolis mass flowmeter that has at least one measuring tube with medium flowing through it involves exciting the measuring tube excited to oscillation, detecting the oscillations of the measuring tube and determining the density of the medium. Detection of the state and a change in the state of a Coriolis mass flowmeter is achieved by determining a calibration temperature and a calibration density sensitivity of the Coriolis mass flowmeter using the detected oscillations, at a temperature differing from the calibration temperature, and a density sensitivity of the flowmeter determined using the detected oscillations. A measurement rate of change of the density sensitivity is determined and a forecast rate of change of the density sensitivity is calculated using a forecast algorithm, and at a given deviation of the measurement rate of change from the forecast rate of change r, a deviation signal is generated.

A method for operating a resonant measurement system has at least one: adjustment device, electric actuation device, electromagnetic vibration generator, vibrating element, and vibration recorder. The adjustment device generates an output signal to trigger the electric actuation device, the electric actuation device provides an electric excitation signal to the electromagnetic drive, the electromagnetic drive excites the vibrating element to the same vibration in at least one normal mode, and the excited vibration is sensed by the vibration recorder and is output as an output signal. To approach, maintain and readjust a resonant point as an operating point of the resonant measurement system, the phase difference between the output signal of the vibration recorder and the adjustment device output signal is acquired, an adjustment deviation is calculated from a predefined phase difference and the acquired phase difference, and the adjustment deviation provided to the adjustment device as an input signal.

Method for operating a resonance-measuring system and respective resonance system

A method for operating a Coriolis mass flowmeter having at least one measuring tube, at least one oscillation generator, at least one oscillation sensor and at least one strain sensor. The oscillation generator is actuated with an oscillation excitation signal and the measuring tube is excited to oscillation by the oscillation generator, the oscillation of the measuring tube is detected by the oscillation sensor and an oscillation sensor signal is generated. The strain sensor is mechanically coupled to the measuring tube via a connection. A change of the mechanical coupling via the connection can be determined by the oscillation of the measuring tube being measured by the strain sensor and a strain sensor signal generated representing oscillation of the measuring tube, a correlation between the strain sensor signal and an oscillation signal representing the oscillation of the measuring tube is identified, and a temporal change of the correlation is determined.

Method for operating a coriolis mass flowmeter and associated coriolis mass flowmeter

A method for operating a Coriolis mass flowmeter () having at least one measuring tube () and at least one sensor (), wherein the sensor () emits an electric sensor signal depending on the temperature of the sensor (), the sensor () is mechanically coupled to the rest of the Coriolis mass flowmeter () via a connection () and the connection () has a thermal resistance. To provide a method for operating a Coriolis mass flowmeter that makes recognition of a change in the connection possible an electric excitation signal is generated, the excitation signal is impressed in the sensor (), the sensor signal influenced by the excitation signal is detected, a change between the detected sensor signal and a reference signal is determined and the change between the detected sensor signal and the reference signal is associated with a change in the thermal resistance.

Method for operating a Coriolis mass flowmeter and corresponding Coriolis mass flowmeter

A method for operating a Coriolis mass flow measuring device having at least one measuring pipe through which a medium flows, at least one vibration generator, at least a first vibration sensor, at least a second vibration sensor and at least a control and analyzing unit. The detection of measurement variables or diagnosis parameters is achieved with increased accuracy and security in that the control and analyzing unit calculates, at least indirectly and in a ratiometric manner, at least a derived secondary variable based on a primary measurement, wherein interested primary measurement signals are transmitted alternately to the control and analyzing unit via different measurement channels and wherein, based on the various values obtained from the different measurement channels regarding the primary measurement signals, compensation values of the transmitted primary measurement signals are calculated and used as a basis for the calculation of the derived secondary variable.

Method for operating a resonance measuring system

Method for operating a resonant measurement system, especially a Coriolis mass flow meter, so as to be excitable in a linear operating range, the driving terminal current triggered by an electric excitation signal and the driving terminal voltage of the electromagnetic drive triggered by the electric excitation signal are measured. The driving power is determined from the driving terminal current and the driving terminal voltage, and if the driving terminal current exceeds a given maximum driving terminal current, and/or if the driving terminal voltage exceeds a given maximum driving terminal voltage and/or if the driving power exceeds a given maximum driving power, the electric excitation signal is limited to a threshold value such that the driving terminal current remains below the given maximum driving terminal current, and/or the driving terminal voltage remains below the given maximum driving terminal voltage, and/or the driving power remains below the maximum driving power.

Method for operating a resonant measurement system

A method for operating a Coriolis mass flowmeter in which a simple and reliable detection of a multi-phase flow is implemented by determining at least one first measured value for at least one state variable that is dependent on the amplitude in a multi-phase medium, exciting the measuring tube with the oscillation generator to oscillate at a predetermined oscillation frequency and a first amplitude, and to oscillate with the excitation frequency and a second amplitude, detecting the resulting oscillation of the measuring tube and determining at least a second measured value for the state variable that is dependent on the amplitude in a multi-phase medium from the determined resulting oscillation, and using the deviation of at least one of the first measured value from at least a corresponding second value as an indicator for the presence of a multi-phase flow.

A Coriolis mass flowmeter () having at least one sensor arrangement (), at least one transducer () and at least one housing (), wherein the sensor arrangement () has at least one measuring tube () that can be excited to oscillation, at least one oscillation generator () and at least one oscillation sensor (), wherein the transducer () at least in part has evaluation and power electronics for controlling and measurement evaluation of the sensor arrangement, wherein the sensor arrangement () and the transducer () are arranged adjacent to one another in a common volume defined by the housing (). A Coriolis mass flowmeter of the described type, in which the physical interaction between the sensor arrangement and transducer is reduced, is realized by the provision of a thermal barrier () arranged at least in a space between the sensor arrangement () and the transducer ().

Coriolis mass flowmeter with thermally, electrically, and magnetically isolated electronics

A method for operating a resonance measuring system, in particular a Coriolis mass flowmeter, an oscillation element is excited to oscillation and the oscillations of the oscillation element are detected by an oscillation sensor and are formed as at least one response signal of a respective eigenform. Orthogonal projection components of the response signal are created, at least a first value corresponding to an eigenfrequency of the resonance measuring system is determined with at least a part of the alternating components of the projection components, at least a second value corresponding to the eigenfrequency of the resonance measuring system is determined with at least a part of the constant components of the projection components and the first and the second value correspondents are used for exciting the resonance measuring system with at least one control in at least one control loop in the eigenform corresponding to the eigenfrequency.

Method for operating a resonance measuring system and a resonance measuring system

A method for operating a resonance-measuring system, in particular, a Coriolis mass flowmeter, having at least one oscillation element, at least one oscillation driver and at least one oscillation sensor, the oscillation element being excited to oscillation in at least one control using at least one control loop by at least one oscillation driver being excited by at least one excitation signal and the excited oscillations of the oscillation element being detected by the oscillation sensors as at least one response signal. At least one set variable of the closed loop is varied in a pre-determined manner and by evaluating at least one resulting excitation signal and/or at least one resulting response signal with the help of a mathematical model of the resonance-measuring system, at least one parameter of the excited eigenform is selectively identified.

Method for operating a resonance-measuring system and a resonance-measuring system

A process for operating a Coriolis mass flow rate measurement device which has at least one measurement tube, the measurement tube being excited into vibrations with a predetermined excitation frequency and a predetermined excitation phase. The response phase which is achieved thereby and the rate of change of the response phase are detected and the excitation frequency is changed by the frequency amount which arises based on a predetermined function from the detected rate of change of the response phase. This makes it possible to maintain continuous measurement of the mass rate of flow even if two-phase flows occur.

Process for operation of a Coriolis mass flow rate measurement device

A method for operating a mass flowmeter that employs the Coriolis principle and through which flows a medium, wherein the mass flowmeter incorporates a measuring tube that can be stimulated to oscillate, the measuring tube is stimulated to oscillate at a minimum of two mutually different frequencies and/or in at least two mutually different natural oscillating modes, and the resulting oscillations of the measuring tube are recorded. The density of the medium flowing through the measuring tube is determined by evaluating the acquired oscillations of the measuring tube on the basis of a physical-mathematical model for the dynamics of the mass flowmeter. In this fashion, highly accurate measurements are obtained for determining the density of the medium flowing through the measuring tube.

Method for operating a mass flow meter

A method for operating a mass flowmeter that employs the Coriolis principle and through which flows a medium, the flowmeter including a measuring tube through which passes a medium, which measuring tube is stimulated into oscillating and the resulting oscillatory response of the measuring tube is measured includes the step of gauging the pressure of the medium flowing through the measuring tube by evaluating the collected oscillatory response on the basis of a physical-mathematical model for the dynamics of the mass flowmeter. Thus, without requiring any additional devices, it is possible for a Coriolis mass flowmeter, apart from measuring the mass flow, to also measure the pressure in the measuring tube.

A method for operating a Coriolis mass flowmeter incorporates a measuring tube through which flows a medium and which is stimulated into oscillating at a minimum of one frequency, the resulting oscillations of the measuring tube being detected and measured. The viscosity of the medium flowing through the measuring tube is determined as a function of the pressure drop along the measuring tube, thus permitting a precise determination of the viscosity in simple and reliable fashion.

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Duisburg, Germany

Kourosh Kolahi