VIBRONIC MEASURING SYSTEM

Description

[0001] The invention relates to a vibronic measuring system formed by means of a vibration-type measuring transducer and electrically connected measuring system electronics, in particular a Coriolis mass flow meter or Coriolis mass flow / density meter, for measuring and / or monitoring at least one measured quantity of a flowing medium.

[0002] A generic vibronic measuring system is described, for example, in DE-A 10 2009 055 069, US-A 2006 / 0266129, US-A 2007 / 0113678, US-A 2010 / 0011882, US-A 2012 / 0123705, US-A 2017 / 0356777, US-B 63 11 136, US-A 56 02 345, US-A 59 26 096, US-B 64 57 372, WO-A 2009 / 136943, WO-A 2019 / 017891, WO-A 2019 / 081169, WO-A described in 2019 / 081170, WO-A 2020 / 126285, WO-A 87 / 06691, WO-A 96 / 05484, WO-A 96 / 08697, WO-A 97 / 26508, WO-A 99 / 39164 or its own unpublished international patent application PCT / EP2020 / 084119.Each of the aforementioned measuring systems comprises a transducer with a pipe arrangement for guiding the flowing fluid, an excitation arrangement for converting electrical power into mechanical power useful for exciting and maintaining forced mechanical vibrations of the pipe arrangement, and a sensor arrangement for detecting mechanical vibrations of the pipe arrangement and for providing vibration signals representing the vibration movements of the pipe arrangement, as well as measuring and operating electronics electrically coupled to the transducer, namely both to its excitation arrangement and to its sensor arrangement, for controlling the transducer and for evaluating vibration signals supplied by the transducer.

[0003] Pipe arrangements shown in US-A 2012 / 0123705, US-A 56 02 345, US-A 59 26 096, WO-A 2009 / 136943, WO-A 87 / 06691, WO-A 96 / 05484, WO-A 96 / 08697, WO-A 97 / 26508, WO-A 99 / 39164 or WO-A 2019 / 017891 each have a first flow divider with exactly two flow openings (serving here as a pipe branch or inlet-side), a second flow divider with exactly two flow openings (identical in construction to the first flow divider and serving here as a pipe union or outlet-side), and two pipes, namely a first pipe and a second pipe. while the pipe arrangements shown in DE-A 10 2009 055 069, WO-A 96 / 08697, US-A 2017 / 0356777, WO-A 2019 / 081169, WO-A 2019 / 081170, WO-A 2020 / 126285 or the aforementioned patent application PCT / EP2020 / 084119 each have a - here serving as a pipe branch orThe system comprises an inlet-side first flow divider with exactly four flow openings, a second flow divider identical in construction to the first flow divider (serving here as a conduit junction) with exactly four flow openings, and four pipes: a first pipe, a second pipe, a third pipe, and a fourth pipe. Each pipe extends from its respective first end to its respective second end, with a specified pipe length, and each pipe has a lumen enclosed by a metallic pipe wall, extending from its respective first end to its respective second end.Furthermore, each of the pipes is connected to each of the first and second flow dividers, such that the first pipe opens with its first end into a first flow opening of the first flow divider and with its second end into a first flow opening of the second flow divider, and the second pipe opens with its first end into a second flow opening of the first flow divider and with its second end into a second flow opening of the second flow divider.that the first tube opens at its first end into a first flow opening of the first flow divider and at its second end into a first flow opening of the second flow divider; the second tube opens at its first end into a second flow opening of the first flow divider and at its second end into a second flow opening of the second flow divider; the third tube opens at its first end into a third flow opening of the first flow divider and at its second end into a third flow opening of the second flow divider; and the fourth tube opens at its first end into a fourth flow opening of the first flow divider and at its second end into a fourth flow opening of the second flow divider. Furthermore, each tube of each tube arrangement is also configured to be filled with a fluid and vibrated during this process.

[0004] In the measuring systems shown in DE-A 10 2009 055 069, US-A 56 02 345, WO-A 2009 / 136943, WO-A 96 / 08697, WO-A 97 / 26508, WO-A 99 / 39164, WO-A 2019 / 017891 or PCT / EP2020 / 084119, each of the excitation arrangements also has two electrodynamic vibration exciters, of which a first vibration exciter is mechanically connected to the first tube and electrically to the measuring and operating electronics, and a second vibration exciter is mechanically connected to the second tube and electrically to the measuring and operating electronics. Each of the first and second vibration exciters is also equipped to convert electrical mechanical power useful in exciting vibrations of the respective pipes, or to introduce a time-varying driving force into the respective pipe at a respective point of application formed by means of the respective vibration exciter on the pipe mechanically connected to it.

[0005] The measuring system electronics are also designed to energize the respective vibration exciters, namely to generate electrical drive signals and feed them into the vibration exciters, such that the first and second tubes or the first, second, third and fourth tubes perform at least partially useful vibrations, namely forced mechanical vibrations with at least one or more useful frequencies, namely vibration frequencies specified by the drive signals, for example also corresponding to one or more resonance frequencies of the tube arrangement, whereby the useful vibrations are also suitable, among other things, to cause Coriolis forces in the measuring medium flowing through the tubes, which depend on the mass flow.To detect vibrations of the pipe assembly, the sensor arrangement comprises four spaced-apart vibration sensors, for example, electrodynamic sensors. A first and a second vibration sensor are mechanically connected to the first pipe and the first and third pipes, respectively, and a third and a fourth vibration sensor are mechanically connected to the second pipe and the second and fourth pipes, respectively. Each vibration sensor is also configured to detect vibrations of the mechanically connected first, second, third, and fourth pipes, respectively, and to generate a corresponding vibration signal, representing these vibrations, and transmit this signal to the measurement system electronics.

[0006] Furthermore, each of the aforementioned measuring systems also includes a support frame designed as a transducer protective housing, which is attached to the flow dividers of the pipe assembly. In the case of the measuring transducers shown in WO-A 96 / 08697, WO-A 2019 / 017891 or PCT / EP2020 / 084119, the support frame and the pipe assembly are specifically detachably connected to each other, for example to allow the replacement of a defective or worn pipe assembly with an intact one on site.

[0007] As discussed in, among others, the aforementioned US-A 2012 / 0123705, US-A 2006 / 0266129, WO-A 99 / 39164, and PCT / EP2020 / 084119, vibration-type transducers, and thus the measurement systems formed by them, can be subjected to a multitude of stresses during their service life, which may extend over several years. These stresses can cause significant deviations of the measurement system from a reference state determined beforehand, for example, during calibration at the manufacturer's plant and / or during commissioning of the measurement system. Consequently, they can significantly reduce the measurement accuracy with which the system ultimately translates the medium parameters to be measured into the corresponding measured values. Examples of such stresses, which ultimately result in irreversible changes to the vibration behavior of at least one measuring tube, whether they occur once or repeatedly, are...Examples of factors that can cause problems, whether permanent or temporary, include overheating, high temperature shocks, or other thermally induced overloads of the at least one measuring tube; high pressure surges in the medium; excessive clamping forces and / or vibration forces exerted on the transducer by the process line, resulting in cracking and / or plastic deformation in the at least one measuring tube; internal erosion of the at least one measuring tube caused by the medium in the transducer, for example, through corrosion and / or abrasion, thus reducing its wall thickness; the formation of deposits on the medium-contacting inner surface of the at least one measuring tube; material fatigue; or other signs of wear on the at least one measuring tube. Furthermore, during the operation of the measuring system, the at least one vibration exciter and each of the vibration sensors may also be affected, for example, by thermally induced overload or...Aging can cause changes relevant to measurement accuracy, such as alterations to the electrical impedance of the transducer. As a result of such stresses, the transducer's inherent transfer function—the function by which the transducer, driven by at least one driver signal, ultimately converts the medium parameter to be measured into the respective vibration signals—varies in a manner that is not immediately apparent or predictable, but which can sometimes be detrimental to the desired high measurement accuracy. Consequently, the entire measurement system operates incorrectly. Furthermore, such overloads, which also affect the overall structural integrity of the transducer, can impair the functionality of the measurement system or, in some cases, even lead to leakage or explosion of the transducer.Such changes, which also affect the operational reliability of measuring systems of the type in question, can have catastrophic consequences for the entire process plant and the people present therein, particularly in the case of toxic and / or highly flammable media or gases under high pressure. In light of this, measuring systems of the type in question are usually subjected to recurring inspections, for example as part of predictive maintenance measures, and, if necessary, such as in the case of diagnosed increased measurement inaccuracy, are occasionally recalibrated or replaced.

[0008] In order to detect as early as possible a deviation of the measuring system from a previously determined reference state (or, for example, in the case of a subsequently installed pipe arrangement or, as proposed, among others, in WO-A 2019 / 017891, a reference state to be implemented on-site) that exceeds a predetermined tolerance, and thus to diagnose errors in the measuring system caused by the transducer, and the associated significant reduction in measurement accuracy or operational reliability of measuring systems of the type in question, the aforementioned changes in such measuring systems are proposed, for example, in US-A 2012 / 0123705, US-A 2010 / 0011882, US-A 2007 / 0113678, WO-A 96 / 05484, WO-A 99 / 39164 or US-A 59 26 096, by comparing current vibration responses of selected components, namely those determined during operation. of the measuring transducer ornamely system parameters representing vibration responses, for example a measuring tube stiffness, a multitude of damping factors, possibly also frequency-selectively acquired, ratios of mechanical natural or resonance frequencies of at least one measuring tube or other predetermined transducer transfer functions describing, and thus characterizing, the measuring system, etc., are applied to selected - broadband or frequency-selective - vibration excitations, such as an impact or a continuous, possibly also multi-modal, vibration excitation of one or more of the natural frequencies of the tubes, with parameters previously determined appropriately in the reference state of the measuring system.

[0009] To compare the transducer transfer functions (system functions of the transducer) or the reference system parameters representing them, in order to generate a corresponding system status or fault message, such as an alarm, when a correspondingly predefined threshold value representing a still acceptable tolerance level is exceeded, i.e., when diagnosing a fault.

[0010] One object of the invention is therefore to improve vibronic measuring systems of the aforementioned type in such a way that – not least, but also with the already conventional, and thus established, measuring systems of the type in question with "onboard" vibration exciters and sensors – the occurrence of any disturbances of the measuring system, such as wear or aging of the respective transducer that reduces the measuring accuracy and / or the operational reliability of the measuring system, and / or faulty assembly or installation of the transducer, can be detected as early and reliably as possible, and possibly also signaled; this should be done in particular largely independently of the medium flowing in the transducer and under largely, if necessary,also the exclusive use of proven designs for such measuring systems, not least for the measuring transducers used in them to date, as well as the extensive retention of proven technologies and architectures of already established measuring and operating electronics.

[0011] To solve this problem, the invention comprises a vibronic measuring system, in particular a Coriolis mass flow meter or a Coriolis mass flow / density meter, for measuring and / or monitoring at least one flow parameter, in particular a time-varying one, in particular a mass flow rate, a volume flow rate and / or a flow velocity, and / or for measuring and / or monitoring at least one material parameter, in particular a time-varying one, in particular a density and / or a viscosity, of a flowing medium, in particular a gas, a liquid or a dispersion, according to claim 1.

[0012] The measuring system, designed, for example, as an in-line measuring device and / or a compact measuring device, comprises: a measuring transducer with a pipe arrangement for guiding the flowing medium, with an excitation arrangement for converting electrical power into mechanical power useful for exciting and maintaining forced mechanical vibrations of the pipe arrangement, and with a sensor arrangement for detecting mechanical vibrations of the pipe arrangement and for providing vibration signals representing the vibration movements of the pipe arrangement, as well as measuring system electronics electrically coupled to the measuring transducer, namely both to its excitation arrangement and to its sensor arrangement, for example by means of electrical connecting lines, for example formed by means of at least one microprocessor and / or arranged in an electronic protective housing, for controlling the measuring transducer and for evaluating vibration signals supplied by the measuring transducer.

[0013] The pipe arrangement comprises a first flow divider, serving, for example, as a pipe branch and / or on the inlet side, with at least two flow openings; a second flow divider, identical in construction to the first flow divider and / or serving as a pipe junction and / or on the outlet side, with at least two flow openings; a first pipe, for example, at least partially curved and / or at least partially straight; and a second pipe, for example, at least partially curved and / or at least partially straight, and / or identical in construction to the first pipe and / or at least partially parallel to the first pipe. Each of the first and second pipes of the pipe arrangement extends from its respective first end to its respective second end with a certain pipe length and each has a connection made of, for example, a metallic,The lumen of the pipe assembly is enclosed by a pipe wall and extends from the first end of each pipe to the second end of the same pipe. Each of the first and second pipes of the pipe assembly is connected to each of the first and second flow dividers, such that the first pipe opens at its first end into a first flow opening of the first flow divider and at its second end into a first flow opening of the second flow divider, and the second pipe opens at its first end into a second flow opening of the first flow divider and at its second end into a second flow opening of the second flow divider. Each of the first and second pipes of the pipe assembly is configured to be filled with a fluid and vibrated during this process. The first and second pipes of the pipe assembly are thus mechanically coupled to each other, at least via the first and second flow dividers.such that forced mechanical vibrations of the first tube cause coupled mechanical vibrations of the second tube, and forced mechanical vibrations of the second tube cause coupled mechanical vibrations of the first tube. The excitation arrangement comprises two vibration exciters, for example, electrodynamic and / or identical in construction, of which a first vibration exciter is mechanically connected to the first tube, for example, positioned centrally on the first tube, and a second vibration exciter is mechanically connected to the second tube, for example, positioned centrally on the second tube, and of which each is configured to convert electrical power into mechanical power using a time-varying electrical current, in particular such that at each,A time-varying driving force acts on the first and second pipes, respectively, by means of the respective vibration exciter at the point of application formed by the mechanically connected pipe. The sensor arrangement comprises at least four vibration sensors, for example, electrodynamic and / or identical and / or spaced apart from each other. A first vibration sensor and a second vibration sensor are positioned on the first pipe, spaced apart from each other, for example, symmetrically to the first vibration exciter, and are, for example, at least partially mechanically connected to the first pipe. A third vibration sensor and a fourth vibration sensor are positioned on the second pipe, spaced apart from each other, for example, symmetrically to the second vibration exciter, and are, for example, at least partially mechanically connected to the second pipe. Each of the first and second vibration sensors is configured as follows:to detect vibrations of the first pipe and convert them into a first or second vibration signal representing the same vibrations, for example, electrical or optical, such that each of the first and second vibration signals contains one or more sinusoidal signal components, each with a frequency corresponding to a vibration frequency of the first pipe; and each of the third and fourth vibration sensors is configured to detect vibrations of the second pipe and convert them into a third or fourth vibration signal representing the same vibrations, for example, electrical or optical, such that each of the third and fourth vibration signals contains one or more sinusoidal signal components, each with a frequency corresponding to a vibration frequency of the second pipe.

[0014] The measuring system electronics are configured to energize the first vibration exciter, namely to feed an electrical first driver signal into the first vibration exciter, causing the first tube to perform forced mechanical vibrations, for example bending vibrations, with one or more vibration frequencies specified by the first driver signal, and the second tube to perform mechanical vibrations coupled with at least one of the vibrations of the first tube; and to energize the second vibration exciter, namely to feed an electrical second driver signal into the second vibration exciter simultaneously with the first driver signal, causing the second tube to perform forced mechanical vibrations, for example bending vibrations, with one or more vibration frequencies specified by the second driver signal, and the first tube to perform mechanical vibrations coupled with vibrations of the second tube.

[0015] In the measuring system according to the invention, the measuring system electronics are further configured in a first operating mode: ▪ to generate and feed into the first vibration exciter both the first driver signal with at least one first useful current component, namely a sinusoidal current component dominant or sole with respect to a current intensity, with an (AC) frequency and a phase angle, and the second driver signal with at least one first useful current component, namely a sinusoidal current component dominant or sole with respect to a current intensity, with an (AC) frequency corresponding to the (AC) frequency of the first useful current components of the first driver signal and a phase angle differing from the phase angle of the first useful current components of the first driver signal, for example by 180°, such that the first and second driver signals have a first drive phase difference, namely one of, for example, 180°,difference between the phase angles of their first useful current components, that the first tube exhibits at least partially, for example predominantly, first useful vibrations, namely mechanical vibrations forced by the (energized) first vibration exciter with at least one first useful frequency, namely a vibration frequency corresponding to the (AC) frequency of the first useful current component of the first driver signal and with a first useful phase, namely a vibration phase corresponding to the phase angle of the first useful current component of the first driver signal, for example at least at the location of the first vibration exciter, and the second tube exhibits at least partially, for example predominantly, second useful vibrations, namely mechanical vibrations forced by the (energized) second vibration exciter with the first useful frequency and with a second useful phase, namely a vibration phase corresponding to the phase angle of the first useful current component of the first driver signal, for example at least at the location of the second vibration exciter,The oscillation phase corresponds to the phase angle of the first useful current components of the second driver signal, for example, such that the second useful oscillations are out of phase or inversely opposite to the first useful oscillations, and / or that the first and second useful oscillations are suitable for inducing Coriolis forces in the flowing medium that depend on the mass flow rate, and that each of the first, second, third, and fourth oscillation signals has a first useful signal component, namely a respective sinusoidal signal component with a frequency corresponding to the first useful frequency, ▪ and to receive and evaluate the first, second, third, and fourth oscillation signals, namely on the basis of the oscillation signals, for example, at least on the basis of each of the useful signal components, which have at least one physical ,

[0016] To determine quantifiable measured values ​​(sequentially). Furthermore, the measuring system electronics are specifically configured to operate in a second operating mode, which may be activated prior to and / or subsequent to the first operating mode, and / or may last for more than 10 ms, and / or may be time-limited, and / or may be restarted repeatedly. ▪ to generate and feed into the first vibration exciter both the first driver signal with a second useful current component, namely a sinusoidal current component dominant or sole with respect to a current intensity, with an (AC) frequency and a phase angle, and the second driver signal with at least one second useful current component, namely a sinusoidal current component dominant or sole with respect to a current intensity, with an (AC) frequency corresponding to the (AC) frequency of the second useful current components of the first driver signal and a phase angle that deviates from the phase angle of the second useful current components of the first driver signal by less than 180°, for example, corresponding to the phase angle of the second useful current components of the first driver signal, in such a way,that the first and second driver signals exhibit a second drive phase difference, for example 0°, which deviates from the first drive phase difference, for example by 180°, namely a difference between the phase angles of their second useful current components; that the first tube exhibits at least partially, for example predominantly, third useful vibrations, namely mechanical vibrations forced by the (energized) first vibration exciter with at least a second useful frequency, namely a vibration frequency corresponding to the (AC) frequency of the second useful current component of the first driver signal and with a third useful phase, namely a vibration phase corresponding to the phase angle of the second useful current component of the first driver signal, for example at least at the location of the first vibration exciter; and the second tube exhibits at least partially, for example predominantly, fourth useful vibrations.namely, to execute mechanical vibrations forced by the (energized) second vibration exciter with the second useful frequency and with a fourth useful phase, namely a vibration phase corresponding, for example, at least at the location of the second vibration exciter, to the phase angle of the second useful current components of the second driver signal, for example, such that the fourth useful vibrations are in phase with the third useful vibrations, and that each of the first, second, third, and fourth vibration signals has a second useful signal component, namely a respective sinusoidal signal component with a frequency corresponding to the second useful frequency, ▪ as well as to receive and evaluate the first, second, third, and fourth vibration signals, namely on the basis of the first and third and / or second and fourth vibration signals received in the second operating mode,For example, to calibrate the measuring system and / or to check or detect whether a defect exists that, for example, reduces the functionality of the measuring system and / or causes a malfunction of the measuring system and / or reduces the integrity of at least one of the first, second, third and fourth vibration signals or measured values ​​obtained therefrom and / or causes a measurement error of measured values ​​obtained from at least one of the first, second, third and fourth vibration signals, based on the respective amplitude of the second useful signal component of the first and third vibration signals and / or based on the respective phase angle of the second useful signal component of the second and fourth vibration signals.A malfunction of the measuring system may be present, for example due to a deposit on the inside of the pipe wall of one or more of the pipes and / or due to a reduction in the wall thickness of one or more of the pipes and / or due to aging of one or more of the vibration sensors and / or vibration exciters and / or due to incorrect assembly and / or installation of the transducer.

[0017] Furthermore, the invention also consists in using the aforementioned measuring system to measure at least one flow parameter, for example a mass flow rate and / or a volume flow rate, and / or at least one material parameter, for example a density and / or a viscosity, of a fluid substance, in particular a gas, a liquid or a dispersion, flowing in a pipeline.

[0018] According to a first embodiment of the invention, it is further provided that the measuring system electronics are configured to also receive and evaluate the first vibration signal and / or the second vibration signal in the second operating mode.

[0019] According to a second embodiment of the invention, it is further provided that the measuring system electronics are configured to determine, on the basis of at least one of the third and fourth vibration signals received in the second operating mode, for example, each of the third and fourth vibration signals, the at least one physical measured quantity (in successive time), quantifying measured values, for example, also to compare with measured values ​​for the same measured quantity determined on the basis of vibration signals received in the first operating mode.

[0020] According to a third embodiment of the invention, it is further provided that the measuring system electronics are configured to obtain or determine the respective useful signal component from at least one of the first and second vibration signals received in the first operating mode, for example, both in the first operating mode and in the second operating mode, for example, from each of the first and second vibration signals, as well as from at least one of the third and fourth vibration signals received in the first operating mode, for example, from each of the third and fourth vibration signals.

[0021] According to a fourth embodiment of the invention, it is further provided that each of the useful signal components of the first, second, third, and fourth oscillation signals has a phase angle that depends on a mass flow rate of the measured substance. Further developing this embodiment of the invention, it is also provided that the measuring system electronics are configured, at least in the first operating mode, to determine mass flow rate measurements—namely, measured values ​​representing the mass flow rate of the flowing measured substance—based on a first (measurement) phase difference, namely a difference between the phase angle of the useful signal component of the first oscillation signal and the phase angle of the useful component of the second oscillation signal, and based on a second (measurement) phase difference, namely a difference between the phase angle of the useful signal component of the third oscillation signal and the phase angle of the useful signal component of the fourth oscillation signal, for example, to calculate these measurements.

[0022] According to a fifth embodiment of the invention, it is further provided that the measuring system electronics are configured to calculate one or more characteristic values ​​for at least one measuring system characteristic on the basis of one or more of the vibration signals received in the second operating mode. This characteristic value defines an operating state, for example, a system function (transfer function) inherent in the measuring system that determines one or more functional dependencies of one or more of the vibration signals on one or more of the driver signals, or the functionality of the measuring system. This can be achieved, for example, by determining the measuring system characteristic value from one or more parameters of a relationship between at least the second useful current components of the first and second driver signals and at least one of the second useful signal components of the first, second,The system function of the measuring system mediating the third and fourth vibration signals is dependent on this embodiment of the invention. It is further provided that the measuring system characteristic number depends on a (system) amplitude ratio between, for example, an absolute or relative deviation of an amplitude of the second useful current component of the second driver signal from an amplitude of the second useful current component of the first driver signal and an, for example, absolute or relative deviation of an amplitude of the second useful signal component of the third vibration signal from an amplitude of the second useful signal component of the first vibration signal and / or an, for example, absolute or relative deviation of an amplitude of the second useful signal component of the fourth vibration signal from an amplitude of the second useful signal component of the second vibration signal.For example, the system amplitude ratio is quantified as a sum of the deviations of the second useful signal components. According to another embodiment of the invention, the measurement system characteristic is determined by a system amplitude ratio between, for example, an absolute or relative deviation of the amplitude of the second useful current component of the second driver signal from the amplitude of the second useful current components of the first driver signal (e1) and, for example, an absolute or relative deviation (Δs13) of the amplitude of the second useful signal component of the third oscillation signal from the amplitude of the second useful signal component of the first oscillation signal and / or an absolute or relative deviation of the amplitude of the second useful signal component of the fourth oscillation signal from the amplitude of the second useful signal component of the second oscillation signal.For example, the measurement system characteristic value can be dependent on, or quantified by, a sum of the deviations of the second useful signal components, the same (system) amplitude ratio. Furthermore, the measurement system characteristic value can also be formed such that it depends on, or quantifies, a (system) phase difference between, the second useful signal component of at least one of the first and second vibration measurement signals, in particular a sum of the second useful signal component of the first and second vibration signals, and the second useful signal component of at least one of the third and fourth vibration measurement signals, in particular a sum of the second useful signal component of the third and fourth vibration signals. Alternatively or additionally, the measurement system electronics can also be configured to correlate one or more characteristic values ​​for the aforementioned measurement system characteristic value with one or more values ​​specific to the measurement system characteristic value.for example, to compare reference values ​​determined by the manufacturer of the measuring system and / or during the manufacture and / or commissioning of the measuring system, for example, one or more reference values ​​representing reduced functionality of the measuring transducer and / or one or more reference values ​​representing a malfunction of the measuring transducer and / or one or more reference values ​​representing a defective measuring transducer, for example, to evaluate and / or quantify a deviation of one or more of the characteristic values ​​from one or more of the reference values, and / or the measuring system electronics may further be configured to determine,whether one or more key figure values ​​for the measuring system key figure are greater than one or more reference values ​​representing reduced functionality of the measuring transducer and / or greater than one or more reference values ​​representing a malfunction of the measuring transducer and / or greater than one or more reference values ​​representing a measuring transducer that is no longer intact, for example in order to issue a message signaling this or declared as a (fault) alarm.

[0023] According to a sixth embodiment of the invention, it is further provided that the measuring system electronics have a non-volatile electronic data storage device (EEPROM) which is designed to retain digital data, for example even without an applied operating voltage, for example to store one or more pre-determined reference values ​​for the measuring system characteristic.

[0024] According to a seventh embodiment of the invention, it is further provided that the measuring system electronics are configured to provide the first and / or second useful current component of the first and second driver signals with an (alternating current) frequency that deviates from a resonance frequency of the first tube and / or a resonance frequency of the second tube by less than 1% of that resonance frequency, fr1, and / or by less than 1 Hz.

[0025] According to an eighth embodiment of the invention, the first and second tubes have at least one common resonant frequency, fr12, and it is further provided that the measuring system electronics are configured to provide, in the first operating mode, the first useful current component of the first and second driver signals, respectively, with an (AC) frequency that deviates from the same common resonant frequency, fr12, of the first and second tubes by less than 1% of the same resonant frequency, fr12, and / or by less than 1 Hz.

[0026] According to a ninth embodiment of the invention, the measuring transducer possesses a first natural bending vibration mode in which the first and second tubes can or do perform anti-phase or anti-parallel mechanical vibrations, for example, bending vibrations (anti-parallel mode), and a second natural bending vibration mode in which the first and second tubes can or do perform in-phase mechanical vibrations, for example, bending vibrations (parallel mode). Further developing this embodiment of the invention, the measuring system electronics are also configured to, in the first operating mode, feed the first and second driver signals, which force the anti-phase mechanical vibrations, into the first and second tubes.to feed the second vibration exciter, for example, the first useful current components of the first and second driver signals with an (AC) frequency that deviates from a resonance frequency, fr12, of the first natural bending vibration mode by less than 1% of that resonance frequency and / or by less than 1 Hz, and / or with phase angles causing a first drive phase difference of 180°, and in the second operating mode to feed the in-phase mechanical vibrations of the first and second driver signals into the first and second drivers respectively.to feed the second vibration exciter, for example, the first useful current components of the first and second driver signals with an (AC) frequency that deviates from a resonance frequency, fr22, of the second natural bending vibration mode by less than 1% of that resonance frequency and / or by less than 1 Hz, and / or with phase angles resulting in a second drive phase difference of 0°. Alternatively or additionally, the excitation arrangement, or the first and second vibration exciters, are further configured, in particular when driven by the first and second driver signals, to excite mechanical (resonance) vibrations of the first and second tubes corresponding to the aforementioned natural parallel vibration mode.

[0027] According to a tenth embodiment of the invention, it is further provided that the measuring system electronics are configured in the first operating mode to generate the first and second driver signals with a first drive amplitude difference, for example a predefinable and / or variable, namely a difference, for example zero, between an amplitude of the first useful current components of the first driver signal and an amplitude of the first useful current components of the second driver signal, and to feed them into the first or second vibration exciter.

[0028] According to an eleventh embodiment of the invention, it is further provided that the measuring system electronics are configured in the second operating mode to generate the first and second driver signals with a second drive amplitude difference corresponding, for example, to the first drive amplitude difference and / or being predefinable and / or variable, namely a difference, for example, of zero, between an amplitude of the second useful current components of the first driver signal and an amplitude of the second useful current components of the second driver signal, and to feed these into the first or second vibration exciter.

[0029] According to a twelfth embodiment of the invention, the measuring system electronics are further configured to determine a (modal) damping of the first and second tubes for second useful vibrations based on the first and second driver signals supplied in the second operating mode, for example, based on the second useful current components of the first and second driver signals, as well as based on the first and third vibration signals, for example, based on the second useful signal components of the first and third vibration signals, and / or the second and fourth vibration signals, for example, based on the second useful signal components of the second and fourth vibration signals. Further developing this embodiment of the invention, it is also provided that the determined (modal) damping of the first and second tubes for second useful vibrations is compared with at least one component that indicates reduced functionality or...to compare a reference value representing a defect in the measuring transducer, or, in the event of a deviation that is too large, namely exceeding a specified (fault) reference value, to issue a message, for example declared as a (fault) alarm.Alternatively or additionally, the measuring system electronics can also be configured to determine a (modal) damping of the first and second tubes for first useful vibrations based on the first and second driver signals fed in during the first operating mode, for example, based on the first useful current components of the first and second driver signals, as well as based on the first and third vibration signals, for example, based on the first useful signal components of the first and third vibration signals, and / or the second and fourth vibration signals, for example, based on the first useful signal components of the second and fourth vibration signals, for example, to relate or normalize the (modal) damping of the first and second tubes for second useful vibrations and to compare it with a correspondingly specified (disturbance) reference value.

[0030] According to a thirteenth embodiment of the invention, it is further provided that the measuring system electronics are configured to detect, on the basis of at least one of the first, second, third and fourth vibration signals received in the second operating mode, in particular their respective second useful signal component, whether a defect, for example, that reduces the functionality of the measuring system and / or causes a malfunction of the measuring system and / or compromises the integrity of at least one of the first, second, third and fourth vibration signals, or vice versa, has occurred.A disturbance of the measuring system that reduces the measured values ​​obtained and / or provokes a measurement error in the measured values ​​obtained therefrom, for example due to a coating on the inside of the pipe wall of one or more of the pipes and / or due to a reduction in the wall thickness of the pipe wall of one or more of the pipes and / or due to aging of one or more of the vibration sensors and / or vibration exciters.

[0031] According to a fourteenth embodiment of the invention, it is further provided that the measuring system electronics are configured to determine a first (test) amplitude difference, namely a difference between the amplitude of the second useful signal components of the first and third oscillation signals, based on the first and third oscillation signals received in the second operating mode, in particular to compare with at least one reference value representing reduced functionality or a defect of the measuring transducer, or, in the event of a deviation that is too large, namely exceeding a predetermined reference value, to output a message, in particular declared as a (fault) alarm.

[0032] According to a fifteenth embodiment of the invention, it is further provided that the measuring system electronics are configured to determine a first (test) phase difference, namely a difference between a phase angle of the second useful signal components of the first and third oscillation signals, on the basis of the first and third oscillation signals received in the second operating mode, in particular to compare with at least one reference value representing reduced functionality or a defect of the measuring transducer, or, in the event of a deviation that is too large, namely exceeding a specified reference value, to output a message, for example declared as a (fault) alarm.

[0033] According to a sixteenth embodiment of the invention, it is further provided that the measuring system electronics are configured to determine a second (test) amplitude difference, namely a difference between the amplitude of the second useful signal components of the second and fourth oscillation signals, based on the second and fourth oscillation signals received in the second operating mode, for example, to compare with at least one reference value representing reduced functionality or a defect of the measuring transducer, or, in the event of a deviation that is too large, namely exceeding a predetermined reference value, to output a message, for example, declared as a (fault) alarm.

[0034] According to a seventeenth embodiment of the invention, it is further provided that the measuring system electronics are configured to determine a second (test) phase difference, namely a difference between a phase angle of the second useful signal components of the second and fourth oscillation signals, based on the second and fourth oscillation signals received in the second operating mode, for example to compare with at least one reference value representing reduced functionality or a defect of the measuring transducer, or, in the event of a deviation that is too large, namely exceeding a specified reference value, to output a message, for example declared as a (fault) alarm.

[0035] According to an eighteenth embodiment of the invention, it is further provided that the disturbance of the measuring system comprises a change, for example irreversible, of one or more vibration properties of the pipe arrangement, for example due to a reduction in the wall thickness of the pipe wall of one or more of the pipes and / or due to plastic deformation of one or more of the pipes and / or due to a coating on an inside of the pipe wall of one or more of the pipes and / or due to a crack in the pipe wall of one or more of the pipes.

[0036] According to a nineteenth embodiment of the invention, it is further provided that the disturbance of the measuring system comprises a change, for example irreversible, of one or more flow properties of the pipe arrangement, for example due to a reduction of a flow cross-section of the pipe arrangement, for example as a result of a blockage of one or more of the pipes and / or as a result of a coating on an inside of the pipe wall of one or more of the pipes.

[0037] According to a twentieth embodiment of the invention, it is further provided that the disturbance of the measuring system comprises a change, for example irreversible, of one or more electromechanical transducer properties, for example due to aging of one or more of the vibration sensors and / or vibration exciters and / or due to a change of a respective mechanical connection between one or more vibration sensors or one or more vibration exciters and the respective tube.

[0038] According to a twenty-first embodiment of the invention, it is further provided that the malfunction of the measuring system comprises a faulty installation and / or assembly of the measuring transducer or the measuring system formed therewith.

[0039] According to a twenty-second embodiment of the invention, it is further provided that the pipe arrangement comprises a first coupler element, for example positioned further away from the second flow divider than from the first flow divider, and mechanically connected to each of the pipes, for example in the form of a plate, as well as a second coupler element, for example positioned further away from the first flow divider than from the second flow divider, and mechanically connected to each of the pipes, for example in the form of a plate and / or identical in construction to the first coupler element.

[0040] According to a twenty-third embodiment of the invention, it is further provided that the measuring transducer possesses a natural bending vibration mode, for example a fundamental bending vibration mode, in which the first and second tubes can or do perform antiphase mechanical vibrations, and wherein the measuring system electronics are configured to feed first and second driver signals into the first and second vibration exciters in the first operating mode, forcing such antiphase mechanical vibrations, for example, by providing the first and second useful current components with an (AC) frequency that deviates from a resonance frequency, fr12, of the bending vibration mode by less than 1% of that resonance frequency and / or by less than 1 Hz.

[0041] According to a twenty-fourth embodiment of the invention, it is further provided that the first vibration exciter is arranged to convert electrical power into mechanical power with a time-varying electrical current in such a way that a time-varying driving force acts on the first tube at a point of application formed by means of the first vibration exciter on the first tube mechanically connected thereto.

[0042] According to a twenty-fifth embodiment of the invention, it is further provided that the second vibration exciter is arranged to convert electrical power into mechanical power with a time-varying electrical current in such a way that a time-varying driving force acts on the second tube at a point of application formed by means of the second vibration exciter on the second tube mechanically connected thereto.

[0043] According to a twenty-sixth embodiment of the invention, it is further provided that the first vibration exciter is not mechanically connected to the second tube.

[0044] According to a twenty-seventh embodiment of the invention, it is further provided that the first vibration exciter has no component mechanically connected to the second tube.

[0045] According to a twenty-eighth embodiment of the invention, it is further provided that the second vibration exciter is not mechanically connected to the first tube.

[0046] According to a twenty-ninth embodiment of the invention, it is further provided that the second vibration exciter has no component mechanically connected to the first tube.

[0047] According to a thirtieth embodiment of the invention, it is further provided that the excitation arrangement has no further vibration exciter mechanically connected to the first tube other than the first vibration exciter.

[0048] According to a thirty-first embodiment of the invention, it is further provided that the excitation arrangement has no further vibration exciter mechanically connected to the second tube, apart from the second vibration exciter.

[0049] According to a first embodiment of the invention, both the first flow divider and the second flow divider each have, for example, exactly four flow openings, and the pipe arrangement comprises a third pipe, which is, for example, at least partially curved and / or at least partially straight and / or at least partially parallel to the first pipe, and a fourth pipe, which is, for example, at least partially curved and / or at least partially straight and / or structurally identical to the third pipe and / or at least partially parallel to the third pipe, wherein each of the third and fourth pipes of the pipe arrangement extends from a respective first end of the respective pipe to a respective second end of the same pipe with a respective pipe length and each has a section enclosed by a pipe wall, for example, made of metal.each tube has a lumen extending from the respective first end of the respective tube to the respective second end of the same tube, and wherein each of the third and fourth tubes of the tube arrangement is connected to each of the first and second flow dividers, such that the third tube opens with its first end into a third flow opening of the first flow divider and with its second end into a third flow opening of the second flow divider, and the fourth tube opens with its first end into a fourth flow opening of the first flow divider and with its second end into a fourth flow opening of the second flow divider, and that each of the third and fourth tubes of the tube arrangement is each configured to be filled with a fluid and vibrated during this process.

[0050] According to a first embodiment of the first further development of the invention, it is further provided that the third and fourth pipes of the pipe arrangement are mechanically coupled to each other at least via the first and second flow dividers, such that forced mechanical vibrations of the third pipe cause mechanical vibrations coupled to it in the fourth pipe and forced mechanical vibrations of the fourth pipe cause mechanical vibrations coupled to it in the third pipe, and / or that forced mechanical vibrations of the first and third pipes, for example, opposing bending vibrations of the first and third pipes, cause mechanical vibrations coupled to them in each of the second and fourth pipes, for example, opposing bending vibrations of the second and fourth pipes, and forced mechanical vibrations of the second and fourth pipes, for example, opposing bending vibrations of the second and fourth pipes,This results in coupled mechanical vibrations in each of the first and third tubes, for example, opposing bending vibrations of the first and third tubes, and / or forced mechanical vibrations in each of the first, second, third, and fourth tubes cause coupled mechanical vibrations in each of the other first, second, third, and fourth tubes, respectively. The first vibration exciter can further be configured to excite mechanical vibrations in the first and third tubes, for example, differentially, and the second vibration exciter can be configured to excite mechanical vibrations in the second and fourth tubes, for example, differentially.

[0051] According to a second embodiment of the first further development of the invention, it is further provided that the first vibration exciter is mechanically connected to both the first tube and the third tube, and that the second vibration exciter is mechanically connected to both the second tube and the fourth tube.

[0052] According to a third embodiment of the first further development of the invention, it is further provided that each of the first and second vibration sensors is configured to detect vibration movements of the first and third tubes, for example differentially, such that each of the first and second vibration signals represents, for example, antiphase vibration movements of the first and third tubes; and wherein each of the third and fourth vibration sensors is configured to detect vibration movements of the second and fourth tubes, for example differentially, such that each of the third and fourth vibration signals, for example antiphase, represents vibration movements of the second and fourth tubes.

[0053] According to a fourth embodiment of the first further development of the invention, it is further provided that the first and second vibration sensors are mechanically connected to both the first tube and the third tube, and that the third and fourth vibration sensors are mechanically connected to both the second tube and the fourth tube.

[0054] According to a fifth embodiment of the first further development of the invention, it is further provided that the first, second, third and fourth pipes are only identical in pairs, for example in such a way that the first pipe is only identical to the third pipe and that the second pipe is only identical to the fourth pipe.

[0055] According to a sixth embodiment of the first further development of the invention, it is further provided that each of the four tubes has a caliber that is equal to the caliber of each of the other tubes.

[0056] According to a seventh embodiment of the first further development of the invention, it is further provided that the pipe wall of each of the four pipes has a wall thickness that is equal to the wall thickness of each of the other pipes.

[0057] According to a second further development of the invention, the measuring system further comprises a support frame, for example designed as a converter protective housing, wherein the support frame and pipe arrangement are attached to each other, for example releasably, by means of their first and second flow dividers.

[0058] According to a first embodiment of the second further development of the invention, it is further provided that the first and second vibration exciters are mechanically connected to the support structure.

[0059] According to a second embodiment of the second further development of the invention, it is further provided that the first, second, third and fourth vibration sensors are mechanically connected to the support frame.

[0060] According to a third further development of the invention, the measuring system further comprises an electronic protective housing for the measuring system electronics, for example attached to a support frame of the measuring transducer.

[0061] A basic idea of ​​the invention is to use the sensitivity of vibration-type measuring transducers, inherent in the parallel vibration modes, to changes in the measuring transducer in order to monitor the functionality of the vibronic measuring system formed thereby, or to be able to detect any disturbance of the measuring system at an early stage based on changes in the vibration characteristics of at least one of the parallel vibration modes, for example even using only "onboard" means.

[0062] The invention and advantageous embodiments thereof are explained in more detail below with reference to exemplary embodiments illustrated in the figures of the drawing. Identical, equivalent, or similarly functioning parts are designated with the same reference numerals in all figures; where clarity requires it or it otherwise appears appropriate, previously mentioned reference numerals are omitted in subsequent figures. Further advantageous embodiments or developments, in particular combinations of aspects of the invention initially described only individually, will also become apparent from the figures of the drawing and / or from the claims themselves.

[0063] Specifically, we show: Fig. 1 schematically shows an embodiment of a measuring system according to the invention; Figs. 2 and 3 schematically show a further variant of a measuring system according to the invention; and Figs. 4 and 5 show phasor diagrams for operation of a measuring system according to the invention. Fig. 1 or according to the Fig. 2 and 3 generated driver and vibration signals.

[0064] In Fig. 1 Figures 2 and 3 are schematically depicted embodiments or configurations of a vibronic measuring system used for measuring and / or monitoring at least one, in particular time-varying, measured quantity of a fluid FL that flows at least intermittently, for example, a fluid that is at least intermittently two-phase or multi-phase or inhomogeneous. The measured quantity can be, for example, a flow parameter such as a mass flow rate ṁ, a volume flow rate, and / or a flow velocity, or a material parameter such as a density ρ and / or a viscosity η of the fluid FL. The measuring system is specifically designed and configured to be integrated into a process line system carrying a fluid FL serving as the measured quantity—for example, a gas, a liquid, or a dispersion—and is operated by the fluid FL, which is supplied to the system via a process line.The system is designed to allow the measured substance FL to flow through the system, at least temporarily, before the fluid is discharged. Furthermore, the measuring system is intended to determine, and in particular calculate and / or output, at least one quantifiable physical quantity (successively over time), possibly also digital measured values ​​XM. The process line can be, for example, a pipeline, such as a pipeline of a filling plant, a refueling device, or another industrial plant.

[0065] As in Fig. 1 , 2As shown in Figure 3 or as can be readily seen from their combination, the measuring system comprises a vibration transducer 10, namely a transducer with a pipe arrangement formed by means of at least two, for example exactly two or exactly four - for example at least pairwise identical - pipes (111, 121, 112, 122), an excitation arrangement (31, 32) for converting electrical power into exciting and maintaining forced mechanical vibrations of the pipes, and a sensor arrangement (41, 42, 43, 44) for detecting mechanical vibrations of the pipe arrangement and for providing vibration signals (s1, s2, s3, s4) representing vibration movements of the pipe arrangement, in particular of its pipes, for example electrical or optical.As is quite common with such measuring transducers, the pipe arrangement can furthermore have two flow dividers (21, 22) connected (fluidically) to at least two pipes.

[0066] The measuring transducer MW is also designed to be connected to the aforementioned process line system via an inlet end 10+, formed, for example, by one of the aforementioned flow dividers and / or enclosed by a connecting flange, and an outlet end 10#, formed, for example, by the other of the aforementioned flow dividers and / or enclosed by a connecting flange, and to be subjected to a flow of the measured substance FL during operation. Furthermore, each of the tubes in its tube arrangement is also designed to guide a partial volume of the measured substance FL into its respective lumen and to vibrate it during this process, for example, by means of a flow control device.Forced mechanical vibrations, corresponding to at least one measured quantity and / or excited by means of the excitation arrangement, are performed around a respective static equilibrium position. This is achieved in particular by vibrating each of the tubes in the tube arrangement while fluid flows through it from its respective first end towards its respective second end. As is quite common with transducers of this type, the aforementioned forced mechanical vibrations can be, at least partially, forced bending vibrations of the tubes around a respective imaginary axis of vibration of the tube arrangement, which intersects the respective tube. This is achieved in particular by ensuring that the aforementioned (two or four) imaginary axes of vibration are essentially parallel to each other – for example, in the case of tubes in a static equilibrium position.In addition to the measuring transducer 10, the measuring system also comprises measuring system electronics 20, which are electrically coupled to it, namely both to the aforementioned excitation arrangement of the measuring transducer and to the aforementioned sensor arrangement of the measuring transducer, for example by means of appropriate electrical connecting lines, and which are formed in particular by means of at least one microprocessor (µC) and / or arranged in an electronic protective housing (200) and / or serve as a transmitter, for controlling the measuring transducer, in particular for causing the aforementioned mechanical vibrations of the pipes, and for evaluating vibration signals supplied by the measuring transducer, for example for determining the aforementioned measured values.

[0067] The aforementioned excitation arrangement of the measuring transducer 10 is specifically designed and configured to convert electrical power supplied therein (by the measuring system electronics 20) into mechanical power, such that the pipe arrangement, in particular each of its pipes, performs forced mechanical vibrations around a static equilibrium position at least temporarily, while the sensor arrangement is designed and configured tois designed to detect mechanical vibrations of the pipe assembly, not least mechanical vibrations and / or bending vibrations of the pipes forced by means of the excitation arrangement, and to provide a first vibration signal s1, a second vibration signal s2, a third vibration signal s3 and a fourth vibration signal s4, of which - for example, electrical - vibration signals s1, s2, s3, s4 each represents at least partially the vibrational movements of one or more of the pipes of the pipe assembly, for example, each by means of a respective variable electrical voltage corresponding to the vibrational movements of the pipes; this in particular in such a way that - as in . Fig. 4 indicated - the vibration signals s1, s2, (or each a spectral signal component sN1 or sN2 thereof) follow a change in the mass flow rate of the measured substance guided in the pipe arrangement with a change in a first phase difference Δcp12, namely a change in the difference between a phase angle of the vibration signal s1 and a phase angle of the vibration signal s2, and that the vibration signals s3, s4 (or each a spectral signal component sN3 or sN2 thereof)sN4 thereof) a change in the mass flow rate of the measured substance guided in the pipe arrangement with a change in a second phase difference Δcp34, namely a change in a difference between a phase angle of the vibration signal s3 and a phase angle of the vibration signal s4, and / or in such a way that each of the aforementioned vibration signals s1, s2, s3, s4 follows a change in the density of the measured substance guided in the pipe arrangement, each with a change in the respective signal frequency of at least one spectral signal component.

[0068] According to a further embodiment of the invention, the pipe arrangement, as already indicated, comprises a first flow divider 21, for example serving as a pipe branch and / or on the inlet side, with at least two flow openings (21a, 21b), a second flow divider 22, for example identical in construction to the first flow divider 21 and / or serving as a pipe junction and / or on the outlet side, with at least two flow openings (22a, 22b), and a first pipe 111, in particular at least partially curved and / or at least partially straight, and a second pipe 112, for example at least partially curved and / or at least partially straight and / or identical in construction to the first pipe and / or parallel to the first pipe at least partially.Each of the tubes 111, 112 extends from its respective first end to its respective second end by a specified length and has a lumen enclosed by a tube wall, for example, made of metal, extending from its respective first end to its respective second end. Each of the tubes 111, 112 of the tube arrangement is connected to each of the flow dividers 21, 22, such that the first end of tube 111 opens into a first flow opening 21a of the flow divider 21 and its second end opens into a first flow opening 22a of the flow divider 22, and the first end of tube 112 opens into a second flow opening 21b of the flow divider 21 and its second end opens into a second flow opening 22b of the flow divider 22.In addition to pipes 111 and 112, the pipe arrangement can include further pipes, for example, as in . Fig. 3 indicated or from a summary of Fig. 2 and 3As can be seen, there are two more pipes, and thus, as also shown in the aforementioned US-A 56 02 345, WO-A 96 / 08697, US-A 2017 / 0356777, WO-A 2019 / 081169, WO-A 2019 / 081170 or the international patent application PCT / EP2020 / 084119, a total of four pipes. Accordingly, according to a further embodiment of the invention, both the flow divider 21 and the flow divider 22 each have, in particular, exactly four flow openings, and the pipe arrangement includes a third pipe 113, which is in particular at least partially curved and / or at least partially straight and / or at least partially parallel to the pipe 111, and a fourth pipe 114, which is in particular at least partially curved and / or at least partially straight and / or structurally identical to the pipe 113 and / or at least partially parallel to the pipe 113.Each of the aforementioned tubes 113, 114 of the tube arrangement extends from a respective first end of the respective tube to a respective second end of the same tube with a respective tube length and each has a lumen enclosed by a, for example, metallic, tube wall, extending from the respective first end of the respective tube to the respective second end of the same tube.Furthermore, each of the pipes 113, 114 is connected to each of the flow dividers 21, 22, such that the pipe 113 opens with its first end into a third flow opening 21c of the flow divider 21 and with its second end into a third flow opening of the flow divider 22, and the pipe 114 opens with its first end into a fourth flow opening 21d of the flow divider 21 and with its second end into a fourth flow opening 22d of the flow divider 22; this is done in such a way that the pipe arrangement has exactly four pipes, and thus, apart from the aforementioned pipes 111, 112, 121, 122, no other pipe is connected to the flow divider 21 and the flow divider 22.

[0069] In the aforementioned case where the pipes of the pipe arrangement are curved, the aforementioned pipe length corresponds to a straight length or a length along an imaginary center line of the respective pipe. The pipe length of pipe 111 is preferably equal to the pipe length of pipe 112. In the case of a pipe arrangement with four pipes, the pipe length of pipe 113 is preferably equal to the pipe length of pipe 114; for example, the pipe length of pipe 111 may be equal to the pipe length of pipe 112 but greater than the pipe length of both pipe 113 and pipe 114, or the pipe length of pipe 113 may be equal to the pipe length of pipe 114 but less than the pipe length of both pipe 111 and pipe 112.According to a further embodiment of the invention, the wall of each of the tubes in the tube arrangement has a predetermined wall thickness – for example, also essentially uniform – and can – as is quite common with tube arrangements of the type in question or with measuring transducers or measuring systems formed therewith – consist, for example, of the same material and / or a metal, in particular, stainless steel or a nickel-based alloy; this can also be the case, for example, that the wall of each of the tubes in the tube arrangement has a wall thickness equal to the wall thickness of the other tube or each of the other tubes and / or that each of the tubes in the tube arrangement has a caliber, namely an inner diameter, equal to the caliber of the other tube or each of the other tubes.According to a further embodiment of the invention, each of the tubes has a diameter of at least 1 mm, for example, also more than 10 mm, and / or the wall thickness of each tube has a minimum wall thickness of at least 0.5 mm, for example, also more than 1.5 mm, and / or is equal to the minimum wall thickness of each of the other tubes. The tubes of the tube arrangement can also, for example, each be formed in one piece, for example, seamlessly or, at least in the case of a metal tube wall, with a welded seam, and / or each be formed by bending a tubular semi-finished product, for example, such that each tube is essentially V-shaped or has a V-shaped silhouette, and / or that each tube ultimately has a tube shape lying in a single (bending) plane.In the aforementioned case where the pipe arrangement has four pipes, the pipes can, for example, be designed in such a way that they are only identical in pairs, for example, that pipe 111 is only identical to pipe 112 and that pipe 113 is only identical to pipe 114.

[0070] To adjust the mechanical vibration characteristics of the pipe assembly, not least to tune one or more resonant frequencies of its pipes, the pipe assembly can be, as also in Fig. 1 as indicated, furthermore a first coupler element 23, positioned in particular further away from the flow divider 22 than from the flow divider 21, and mechanically connected to each of its tubes, for example, a plate-shaped element, and at least one second coupler element 24, positioned in particular further away from the flow divider 21 than from the flow divider 22, and mechanically connected to each of its tubes, for example, a plate-shaped element and / or identical in construction to the coupler element 23. For connecting the tube arrangement orThe measuring transducer or measuring system formed by this, together with the aforementioned process line carrying the fluid FL, can also have a first connection flange on the flow divider 21 – for example, for connecting the pipe assembly to a line segment of the aforementioned process line that supplies the fluid FL during operation – and a second connection flange on the flow divider 22 – for example, for connecting the pipe assembly to a line segment of the process line that discharges the fluid FL. Each of the aforementioned connection flanges can, for example, have a sealing surface for a fluid-tight or leak-free connection of the pipe assembly to the respective line segment of the process line.

[0071] According to a further embodiment of the invention, the measuring system also comprises a support frame 100, which is in particular rigid against bending and / or torsion, wherein – as also in Fig. 1 schematically depicted – the aforementioned support frame 100 and the pipe arrangement are attached to one another, for example, releasably, by means of the flow dividers 21, 21. To protect the transducer or its components from harmful environmental influences, to prevent unwanted noise emissions from the vibrating pipes, or to collect measuring fluid that has escaped from a leaking pipe arrangement, the aforementioned support frame 100 can, as is quite common in vibronic measuring systems of the type in question, also be designed as a transducer protective housing enclosing the pipes 111, 112 of the pipe arrangement, for example, such that the transducer protective housing has a pressure resistance that is greater than the maximum pressure resistance of the pipes of the pipe arrangement and / or that is more than 50 bar.

[0072] In the measuring system according to the invention, as already mentioned, each of the tubes of the tube arrangement, i.e., each of the tubes 111, 112 and, if applicable, also of the tubes 113, 114, is specifically configured to be permeated by a flow of measuring medium FL (or a partial volume thereof) and vibrated during this process. For this purpose, the excitation arrangement in the measuring system according to the invention has two vibration exciters 31, 32, for example, electrodynamic and / or identical in construction, of which one, for example, electrodynamic or piezoelectric, first vibration exciter 31 is mechanically connected to the tube 112 (but not to the tube 113), for example, positioned centrally on the tube 111, in particular.namely, no (excitation) component mechanically connected to the tube 112, and of which a second vibration exciter 32, for example electrodynamic or piezoelectric, is mechanically connected to the tube 112 (but not to the tube 111), for example, positioned centrally on the tube 112, in particular, does not have a (excitation) component mechanically connected to the tube 111. Each of the vibration exciters 31, 32 is also each configured to convert electrical power into mechanical power with a time-varying electrical current, in particular such that a time-varying driving force acts on the respective tube at a respective point of application formed by the respective vibration exciter on the tube mechanically connected to it.According to a further embodiment of the invention, it is further provided that the excitation arrangement has no further vibration exciter mechanically connected to the tube 111 in addition to the vibration exciter 31 and / or that the excitation arrangement has no further vibration exciter mechanically connected to the tube 112 in addition to the vibration exciter 32.

[0073] In the aforementioned case where the pipe arrangement comprises four pipes, according to a further embodiment of the invention, the vibration exciter 31 is configured to excite mechanical vibrations of the two pipes 111, 113, and the vibration exciter 32 is configured to excite mechanical vibrations of the two other pipes 112, 114; this is done in particular in such a way that the vibration exciter 31 acts differentially on the two pipes 111, 113, namely can introduce or does introduce only opposite excitation forces into the two pipes 111, 113, and that the vibration exciter 32 acts differentially on the two pipes 112, 114, namely can introduce or does introduce only opposite excitation forces into the two pipes 112, 114.The vibration exciter 31 can, for example, be mechanically connected to both pipe 111 and pipe 113, and the vibration exciter 32 can, accordingly, be mechanically connected to both pipe 112 and pipe 114, for example, such that the aforementioned respective driving force acts on both pipe 111 and pipe 113, or on both pipe 112 and pipe 114. Finally, in the other case, where the measuring system comprises the aforementioned support frame and the pipe arrangement with exactly two pipes, the vibration exciters 31 and 32 can, for example, be partially mechanically connected to the support frame 100, for example, such that the aforementioned respective driving force acts on both pipe 111 and pipe 112, respectively, and on the support frame itself.

[0074] To generate the aforementioned vibration signals s1, s2, s3, s4, the sensor arrangement comprises at least four vibration sensors, for example, identical in construction and / or spaced apart from one another. A first vibration sensor 41 and a second vibration sensor 42, for example, electrodynamic or optical, are positioned on the tube 111 at a distance from one another, for example, symmetrically to the vibration exciter 31. A third vibration sensor 43 and a fourth vibration sensor 44, for example, electrodynamic or optical, are positioned on the tube 112 at a distance from one another, in particular symmetrically to the vibration exciter 32. Each of the vibration sensors 41, 42 is configured to detect vibrations of the tube 111 and accordingly feed them into the aforementioned vibration signal s1 or s4.to convert the aforementioned vibration signal s2, and each of the vibration sensors 41, 42 is configured to detect vibrations of the pipe 112 and convert them accordingly into the aforementioned vibration signal s3 or the aforementioned vibration signal s4; in particular, such that each vibration signal s1, s2, s3, s4 represents the corresponding vibrations, or that each of the vibration signals s1, s2, s3, s4 contains one or more sinusoidal signal components, each with a frequency corresponding to a vibration frequency of the vibrations of the respective pipe 111 or 112. As also in . Fig. 1 indicated or from a summary of Fig. 1 , 2 and 3It is readily apparent that the vibration sensors 41, 42, 43, 44 can also be positioned, for example, such that vibration sensor 41 and vibration sensor 43 each detect inlet-side vibration movements of the pipe 111 and that vibration sensor 42 and vibration sensor 44 each detect outlet-side vibration movements of the pipe 112.

[0075] Furthermore, the vibration sensors can, for example, be positioned such that the vibration sensor 41 is equidistant from the aforementioned flow divider 21 as the vibration sensor 42 is from the aforementioned flow divider 22 and / or that the vibration sensor 43 is equidistant from the aforementioned flow divider 21 as the vibration sensor 44 is from the aforementioned flow divider 22, and / or in such a way that the two vibration sensors 41, 42 are each equidistant from the aforementioned vibration exciter 31 and / or the two vibration sensors 43, 44 are each equidistant from the aforementioned vibration exciter 32.

[0076] Particularly in the aforementioned case where the vibration sensors are electrodynamic, i.e., constructed in the manner of a moving coil or voice coil, a further embodiment of the invention provides that both vibration sensor 41 and vibration sensor 42 are at least partially mechanically connected to the tube 111, but in particular not to the tube 112, and that both vibration sensor 43 and vibration sensor 44 are at least partially mechanically connected to the tube 112, but in particular not to the tube 111. In the other case, where the measuring system has a support frame and the tube arrangement comprises exactly two tubes, the vibration sensors can accordingly also be partially mechanically connected to the support frame; for example, such that vibration sensors 41, 42, 43, and 44 each detect vibrational movements of the tubes 111 and 112, respectively, relative to the support frame.For this purpose, the vibration sensors 51, 52 can each be mechanically connected to both the tube 111 and the support frame, and the vibration sensors 53, 54 can each be mechanically connected to both the tube 112 and the support frame. For the other case described above, where the tube arrangement has four tubes, the following applies, as also in . Fig. 2 and 3As indicated, or readily apparent from their combination, both vibration sensor 41 and vibration sensor 42 can be mechanically connected to each of the two pipes 111, 113, and both vibration sensor 43 and vibration sensor 44 can be mechanically connected to each of the two pipes 112, 114, for example, such that vibration sensor 41 and vibration sensor 43 each detect inlet-side vibrations of the pipes 111, 112, 113 and 114 respectively, and that vibration sensor 42 and vibration sensor 44 each detect outlet-side vibrations of the pipes 111, 112, 113 and 114 respectively. Furthermore, vibration sensors 41, 42 can be configured in this case to detect opposing, i.e., out-of-phase, vibrations, if necessary.to also detect opposing vibration movements of the pipes 111, 1113 and to convert them into the respective vibration signal s41, s42 (representing the same vibration movements) and accordingly each of the aforementioned vibration sensors 43, 44 can also be configured to detect opposing, i.e., out-of-phase, possiblyto detect opposing vibration movements of the pipes 112, 114 and to convert them into the respective vibration signal (representing the same vibration movements); for example, by means of the vibration sensors 41, 42 being configured to detect the vibration movements of the two pipes 111, 113 differentially, namely to convert only opposing vibration movements of the same pipes 111, 113 into the respective vibration signal s1, s2, and by means of the vibration sensors 43, 44 being configured to detect the vibration movements of the two pipes 112, 114 differentially, namely to convert only opposing vibration movements of the same pipes 112, 114 into the respective vibration signal s3, s4. For this purpose, the vibration sensors 51, 52 can each be mechanically connected to both the tube 111 and the tube 113, and the vibration sensors 53, 54 can each be mechanically connected to both the tube 112 and the tube 114.

[0077] To further improve the accuracy with which the XM measured values ​​are determined, the transducer – as also in Fig. 1 schematically represented - furthermore, temperature sensors 71, 72, for example directly attached to one of the pipes of the pipe arrangement, are useful for detecting temperatures within the pipe arrangement and providing corresponding temperature measurement signals θ1, θ2 and / or strain sensors, for example directly attached to one of the pipes of the pipe arrangement, are useful for detecting mechanical stresses within the pipe arrangement and providing corresponding strain measurement signals.

[0078] As already mentioned, in addition to the transducer 10, the measuring system comprises measuring system electronics 20 that are electrically coupled to it, to the excitation arrangement of the transducer 10, and to its sensor arrangement. The measuring system electronics 20 can, for example, be programmable and / or remotely configurable, for instance, by means of at least one microprocessor and / or at least one digital signal processor (DSP) and / or by means of a programmable logic gate (FPGA) and / or by means of a customer-specific programmed logic gate (ASIC). Furthermore, the measuring system electronics 20 can be supplied with the electrical energy required during operation by means of internal energy storage devices and / or externally via a connecting cable. The electrical coupling or...Connecting the measuring transducer 10 to the measuring system electronics 20 can be accomplished using appropriate electrical connecting cables and cable glands. The connecting cables can be designed, at least partially, as electrical conductors, or at least partially as conductors sheathed in electrical insulation, e.g., in the form of twisted-pair cables, ribbon cables, and / or coaxial cables. Alternatively or additionally, the connecting cables can also be formed, at least partially, by conductor tracks on a printed circuit board, particularly a flexible one, which may be coated. The measuring system electronics 20 can also be – as in . Fig. 1 schematically represented - for example, housed in a suitable, in particular impact- and / or explosion-proof and / or at least splash-proof, dedicated electronics housing 200 and also designed in such a way that it can exchange measurement and / or other operating data, such as status messages, with a higher-level (not shown here) electronic data processing system, for example a programmable logic controller (PLC), a personal computer and / or a workstation, via a data transmission system, for example a fieldbus system and / or wirelessly via radio, during operation of the measuring system, such as current measured values ​​or setting and / or diagnostic values ​​used for the control of the measuring system.Accordingly, the measuring system electronics 20 can, for example, include such a transmitting and receiving circuit COM, which, during operation, is powered by a (central) evaluation and supply unit provided in the aforementioned data processing system and located remotely from the measuring system. For example, the measuring system electronics 20 (or its aforementioned transmitting and receiving circuit COM) can also be designed such that it can be electrically connected to the aforementioned external electronic data processing system via a two-wire connection 2L, which may also be configured as a 4-20 mA current loop, and can thereby obtain both the electrical power required for the operation of the measuring system from the aforementioned evaluation and supply unit of the data processing system and, if necessary,The measurement system electronics 20 can transmit digitized measured values ​​to the data processing system, for example, by (load) modulation of a DC supply current fed by the evaluation and supply unit. Furthermore, the measurement system electronics 20 can also be designed to operate nominally with a maximum power of 1 W or less and / or be intrinsically safe. The measurement system electronics 20 can also be modularly designed, for example, such that various electronic components of the measurement system electronics 20, such as a measurement and evaluation circuit DSV (for example, formed by one or more microprocessors and / or by one or more digital signal processors) for processing and evaluating the (oscillatory) measurement signals provided by the transducer 10, a driver circuit Exc for controlling the transducer, etc., can be integrated.whose excitation arrangement, an internal power supply circuit VS for providing one or more internal operating voltages, and / or the aforementioned transmit and receive circuit COM for communication with a higher-level measurement data processing system or an external fieldbus, are each arranged on one or more separate printed circuit boards and / or each formed by means of one or more separate microprocessors. As shown in the... Fig. 1 As can be seen, the aforementioned transmit and receive circuit COM can, for example, also be intended for the output (xm) of measured values ​​(XM) determined internally by the measurement system, for example by the aforementioned measurement and control circuit DSV. Accordingly, the transmit and receive circuit COM can also be configured to convert received measured values ​​XM into an output signal xm that provides the same measured values ​​XM and conforms to an industry standard, such as DIN IEC 60381-1:1985-11, IEC 61784-1 CPF1 (Foundation Fieldbus), IEC 61784-1 CPF3 (Profibus), IEC 61158 or IEC 61784-1 CPF9 (HART).To visualize measurement values ​​(XM) and / or status messages generated internally by the measurement system, such as an error message or an alarm, on-site, the measurement system may also have a display and control element (HMI) that communicates, at least temporarily, with the measurement system electronics 20. This could include an LCD, OLED, or TFT display placed behind a window provided therein in the aforementioned electronics housing 200, as well as a corresponding keypad and / or touchscreen. If the measurement system has the aforementioned support frame 100, which is designed as a converter protective housing, the electronics protective housing 200 can be used as described in [reference missing]. Fig. 1 schematically represented, for example attached to the same support structure.

[0079] The measuring system electronics 20 are specifically configured to energize the vibration exciter 31, namely to feed an electrical first driver signal e1 into the first vibration exciter 31, and to energize the second vibration exciter 32, namely to feed an electrical second driver signal e2 into the second vibration exciter 32 simultaneously with the first driver signal e1, thereby causing the pipe 111 or the pipes 111, 113 to perform forced mechanical vibrations, for example, bending vibrations, with one or more vibration frequencies specified by the driver signal e1, and the pipe 112 or the pipes 112, 114 to perform forced mechanical vibrations, for example, bending vibrations, with one or more vibration frequencies specified by the driver signal e2. To generate the driver signals e1, e2, the measuring system electronics 20 can – as also in Fig. 1 schematically represented and, as is quite common with such measurement systems, one or more separate ones, each using one or more phase-controlled loops (PLLs). phase locked loop ) formed, driver circuits Exc exhibit.

[0080] Furthermore, the measuring system electronics of the measuring system according to the invention are configured in a first operating mode to generate and feed into the vibration exciter 31 both the driver signal e1 with at least one first useful current component eN11, namely a sinusoidal current component with a (current) frequency and phase angle that is dominant or the only component with respect to a current intensity, and the driver signal e2 with at least one first useful current component eN21, namely a sinusoidal current component with respect to a current intensity that is dominant or the only component with respect to a current intensity, having a (current) frequency corresponding to the (AC) frequency of the useful current components eN11 of the driver signal e1 and a phase angle that deviates from the phase angle of said useful current components eN11 of the driver signal e1, for example by 180°, such that the driver signals e1,e2 exhibits a first drive phase difference Δe1, namely a difference, in particular of 180°, between the phase angles of their (first) useful current components eN11, eN21, and that the pipe 111 exhibits at least partially, in particular predominantly, first useful vibrations, namely mechanical vibrations forced by the (energized) vibration exciter 31 with at least one first useful frequency fN1, namely a vibration frequency corresponding to the (alternating current) frequency of the useful current component eN11 and with a first useful phase, namely a vibration phase corresponding, in particular at least at the location of the vibration exciter 31, to the phase angle of the useful current component eN11, and the pipe 12 exhibits at least partially, in particular predominantly, second useful vibrations, namely mechanical vibrations forced by the (energized) vibration exciter 32 with the first useful frequency fN1 and with a second useful phase, namely one, especially at least at the location of the second vibration exciter,The oscillation phase corresponds to the phase angle of the useful current components eN21 of the driver signal e2; this is done in such a way that the second useful oscillations (of tube 112) are out of phase or inversely opposite to the first useful oscillations (of tube 111), or that the first and second useful oscillations are suitable for inducing Coriolis forces in the flowing medium that depend on the mass flow rate. As a result of the aforementioned first and second useful oscillations, each oscillation signal s1, s2, s3, s4 also exhibits – as in , Fig. 4 As indicated, each first (spectral) useful signal component sN11, sN21, sN31, or sN41, namely a respective sinusoidal signal component with a frequency corresponding to the first useful frequency fN1, is generated. According to a further embodiment of the invention, the measuring system electronics are further configured, in the first operating mode, to generate the driver signals e1, e2 with a first drive amplitude difference, which can be specified and / or varied, namely a difference (e.g., zero) between the amplitude of the useful current components eN11 of the driver signal e1 and the amplitude of the useful current components eN21 of the driver signal e2, and to feed this difference into the vibration exciter 31 or 32.

[0081] The program codes executed during operation of the measuring system in the measuring system electronics 20, for example, in one or more of the aforementioned microprocessors or digital signal processors of the measuring system electronics 20, can each be persistently stored, for example, in one or more non-volatile data storage devices (EEPROMs) of the measuring system electronics 20, which can retain digital data even without an applied operating voltage. Upon startup, these data are loaded into a volatile data storage device (RAM) provided in the measuring system electronics 20 or the aforementioned measuring and evaluation circuit DSV, for example, integrated into the microprocessor. The vibration signals s1, s2, s3, s4 are available for processing in the microprocessor or...In the digital signal processor, the signals must first be converted into corresponding digital signals using appropriate analog-to-digital converters (A / D), for example, by digitizing the respective signal voltage of each of the – here electrical – vibration signals s1, s2, s3, s4 in a suitable manner; see, for example, the aforementioned US-B 63 11 136. Accordingly, in the measurement system electronics 20, for example, in the aforementioned measurement and evaluation circuit DSV, appropriate analog-to-digital converters for the vibration signals s1, s2, s3, s4 and / or at least a non-volatile electronic data storage device (EEPROM) may be provided, which is designed to retain digital data, for example, even without an applied operating voltage.

[0082] The aforementioned (AC) frequency of the useful current components eN11 and eN21, i.e., the first and second useful frequencies, respectively, can, for example, correspond to a resonance frequency of the tube arrangement that depends on the density of the measuring medium FL guided in the tube arrangement—for example, namely, a lowest resonance frequency of tube 111 and / or tube 112. Accordingly, the measuring system electronics 20, according to a further embodiment of the invention, is further configured to provide the useful current component eN1 of the driver signal e1 and the useful current component eN2 of the driver signal e2 each with an (AC) frequency that deviates from a resonance frequency fr1 of tube 111 by less than 1% of that resonance frequency fr1 and / or by less than 1 Hz, or that deviates from a resonance frequency fr2 of tube 112 by less than 1% of that resonance frequency fr2 and / or by less than 1 Hz.In the typical case where the aforementioned resonant frequencies fr1, fr2 are equal (fr1 = fr2), and thus the tubes 111, 112 have at least one common resonant frequency fr12, the measuring system electronics can further be configured, in particular, to provide the useful current component eN1, eN2 with an (AC) frequency that deviates from the aforementioned common resonant frequency fr12 by less than 1% of that resonant frequency fr12 and / or by less than 1 Hz. The aforementioned common resonant frequency fr12 can, for example, be a resonant frequency fr12 of a (first) natural (bending) vibration mode inherent in the measuring transducer, for example, a fundamental bending vibration mode, in which the two tubes 111, 112 can perform opposing or out-of-phase mechanical (bending) vibrations.to execute, therefore the measuring system electronics can also be set up to feed in the first operating mode namely antiphase mechanical vibrations forcing driver signals e1, e2 into the vibration exciters 31, 32.

[0083] In addition to generating the two driver signals e1, e2, the measuring system electronics 20 are also configured to receive and evaluate the vibration signals s1, s2, s3, s4 in the first operating mode, namely to determine the aforementioned measured values ​​for at least one physical quantity based on the vibration signals s1, s2, s3, s4, and not least on at least one of the aforementioned useful signal components sN11, sN21, sN31, sN41, for example, mass flow measured values, namely the mass flow values ​​XM representing the mass flow of the measured substance FL, based on the aforementioned first phase difference Δcp12 and / or on the aforementioned second phase difference Δϕ34, and / or to generate at least one of the vibration signals s1, s2, s3, s4 based on at least one signal frequency, for example, based on the aforementioned useful frequency. fN 1 at least one of the vibration signals s1, s2, s3, s4, density measurements,namely to generate measured values ​​representing the density ρ of the measured substance FL; This also applies, for example, to measuring systems of the type in question, not least also to those derived from the aforementioned US-A 2006 / 0266129, US-A 2007 / 0113678, US-A 2010 / 0011882, US-A 2012 / 0123705, US-A 2017 / 0356777, US-A 56 02 345, US-A 59 26 096, US-B 64 57 372, WO-A 2009 / 136943, WO-A 2019 / 017891, WO-A 2019 / 081169, WO-A 2019 / 081170, WO-A 87 / 06691, the WO-A 96 / 05484, WO-A 96 / 08697, WO-A 97 / 26508, WO-A 99 / 39164 or WO-A 2020 / 126285 known measuring systems in a typical manner.

[0084] According to a further embodiment of the invention, the measuring system electronics 20 are accordingly also configured to generate mass flow measurement values ​​representing the mass flow in the first operating mode based on the aforementioned phase differences Δϕ12, Δcp34, for example by means of a phase difference-to-mass flow measurement characteristic function programmed into the measuring system electronics, namely a characteristic function of the measuring system electronics, optionally also designed as a (linear) parameter function, according to which a determined phase difference is converted into mass flow measurement values ​​X m. According to a further embodiment of the invention, the measuring system electronics 20 are also configured to determine the resonance frequency fR1 or the resonance frequency fr12, for example, based on the useful current component eN1, eN2, at least one of the driver signals e1, e2 and / or the useful signal component sN11, sN21, sN31, respectively.sN41 to determine frequency values ​​Xf representing at least one of the vibration measurement signals s1, s2, s3, s4, namely the resonance frequency fR1 or fR12; this can also be used, for example, to calculate density measurement values ​​Xρ representing the density based on such frequency values ​​Xf, for instance according to a corresponding resonance frequency-to-density measurement characteristic function of the measurement system electronics. Alternatively or additionally, the measurement system electronics 20 can also be provided or configured to generate viscosity measurement values, namely measurement values ​​representing the viscosity of the measured substance FL, in the first operating mode based on at least one of the vibration measurement signals s1, s2, s3, s4, and / or at least one of the driver signals e1, e2, for example according to a damping-to-viscosity measurement characteristic function of the measurement system electronics. The processing of the vibration measurement signals s1, s2, s3, s4, if applicable.The aforementioned driver circuit(s) Exc, which is quite common in such measuring systems, can also be controlled - as in . Fig. 2 or 3 each shown schematically - for example also by means of the aforementioned measuring and evaluation circuit DSV.

[0085] The program codes executed during operation of the measuring system in the measuring system electronics 20, for example, in one or more of the aforementioned microprocessors or digital signal processors of the measuring system electronics 20, can each be persistently stored, for example, in one or more non-volatile data storage devices (EEPROMs) of the measuring system electronics 20, which can retain digital data even without an applied operating voltage. Upon startup, these data are loaded into a volatile data storage device (RAM) provided in the measuring system electronics 20 or the aforementioned measuring and evaluation circuit DSV, for example, integrated into the microprocessor. The vibration measurement signals s1, s2, s3, s4 are available for processing in the microprocessor or...In the digital signal processor, the signals must first be converted into corresponding digital signals using appropriate analog-to-digital converters (A / D), for example, by digitizing the respective signal voltage of each of the – here electrical – vibration measurement signals s1, s2, s3, s4 in a suitable manner; see, for example, the aforementioned US-B 63 11 136. Accordingly, the measurement system electronics 20, for example, the aforementioned measurement and evaluation circuit DSV, can include appropriate analog-to-digital converters for the vibration measurement signals s1, s2, s3, s4 and / or at least a non-volatile electronic data storage device (EEPROM) designed to retain digital data, for example, even without an applied operating voltage. To further improve the accuracy with which the measured values ​​XM are ultimately determined, the measuring transducer – as also in . Fig. 2 or 3 each schematically represented and as is quite common with such measuring systems - furthermore, also temperature sensors 71 (71, 72) serving to detect temperatures within the pipe arrangement and to provide one or more corresponding temperature measurement signals θ1 (θ1, θ2), for example, each directly attached to at least one pipe of the pipe arrangement, and / or a strain sensor serving to detect mechanical stresses within the pipe arrangement and to provide one or more corresponding strain measurement signals, for example, each directly attached to one of the pipes of the pipe arrangement, and the measuring system electronics may further be configured to receive and process the temperature or strain measurement signals, in particular to use them in determining the measured values.

[0086] As already mentioned, vibration-type transducers, and thus the vibronic measuring systems formed with them, can be subjected to a multitude of stresses during their service life, which can cause significant deviations of the transducer or the measuring system from a previously determined reference state, for example, an initial delivery state and / or a state during the commissioning of the measuring system on site; this can particularly occur in such a way that the pipe assembly, for example due to overloading, suffers damage that changes the vibration characteristics of at least one pipe, or that the transducer as a whole is damaged because, among other things, one or more system functions (transfer functions) inherent in the transducer or corresponding measurement functions formed in the measuring system are no longer correct compared to a respective (reference) system function of the original transducer.The (reference) measurement function of the measuring system is accordingly altered. Changes in the vibration characteristics of the at least one tube can, for example, be attributed to changes in one or more modal parameters, namely bending stiffness, mass, and / or damping, each determining one of the aforementioned vibration modes. This results in one or more (natural) vibration modes deviating from their respective counterparts when the transducer is in the reference state. This regularly occurs in such a way that an original—typically essentially homogeneous or uniform—distribution of the aforementioned (system) parameters (modal) bending stiffness, (modal) mass, and (modal) damping is altered, becoming increasingly uneven. Furthermore, during the operating time of the measuring system, the at least one vibration exciter, as well as each of the vibration sensors, can also be affected, for example, by thermally induced (over)loading or...Aging can cause changes relevant to measurement accuracy, such as alterations to the electrical impedance of the transducer. Overloads that can damage the pipe assembly or the transducer as a whole can include, for example, high temperatures or temperature shocks, excessive pressures or pressure surges in the fluid being measured, excessive clamping forces and / or vibration forces exerted on the transducer by the process control, detrimental properties of the fluid being measured, or material fatigue, among other factors.a significant reduction in the wall thickness of the pipe wall, for example due to corrosion and / or abrasion of the pipe wall of at least one pipe caused by the measuring medium, or a significant reduction in the flow cross-section of the pipe arrangement, for example due to at least partial clogging of the pipe arrangement and / or due to a solid coating on the inside of the pipe wall in contact with the measuring medium, a plastic deformation of the at least one pipe or even a crack formation within the pipe arrangement, for example namely the pipe wall, may result, and thus even lead to the transducer no longer being safe.

[0087] The aforementioned damage to the transducer or its tube assembly can, in particular, lead to one or more system functions or a corresponding measurement function—for example, a (scale) zero point and / or a change in the phase difference of the first useful signal components related to a change in mass flow rate—corresponding to the (measurement) sensitivity (slope of the characteristic curve function) of the aforementioned phase difference-to-mass flow rate measurement characteristic curve function, being subject to corresponding changes over time, especially exhibiting drift. As a result of such (over-)loads of the transducer, which may occur repeatedly and / or over a longer period, it can be damaged to such an extent during its operating life that its functionality or the functionality of the measurement system as a whole is significantly impaired.is completely restricted; this may also result in a disturbance or a malfunction of the measuring system, possibly leading to measurement errors in the determination of the measured values, for example because the integrity of at least one of the vibration measurement signals or the measured values ​​obtained from them is significantly reduced, thus significantly reducing the measurement accuracy of the measuring system with which it ultimately maps the measured quantity to be recorded into the corresponding measured values ​​compared to an initial or nominal measurement accuracy of the original or intact measuring system.

[0088] To check the measuring system, for example, to detect and report any changes in the measuring transducer, such as its mechanical and / or electrical properties, or any resulting defect in the measuring transducer or the measuring system formed therewith, as early and reliably as possible, the measuring system electronics 20 of the measuring system according to the invention are further configured, in a second operating mode activated, for example, prior to and / or subsequent to the first operating mode, in particular also during a self-diagnosis of the measuring system, to generate the driver signal e1 with a second useful current component eN12, namely a sinusoidal current component with a (alternating current) frequency and phase angle that is dominant or the only component with respect to a current intensity, and to feed this into the vibration exciter 31.as well as generating the driver signal e2 with at least one second useful current component eN22, namely a sinusoidal current component dominant with respect to a current intensity or the only sinusoidal current component with an (alternating current) frequency corresponding to the (alternating current) frequency of the useful current components eN12 of the driver signal e1 and a phase angle that deviates from the phase angle of the useful current components eN12 of the driver signal e1 by less than 180°, for example, corresponding to the phase angle of the useful current components eN12 of the driver signal e1, and feeding it into the vibration exciter 32, such that the driver signals e1, e2 have a second drive phase difference that deviates from the aforementioned drive phase difference Δe1, for example, by 180°, namely a difference, for example, of 0°, between the phase angles of their (second) useful current components eN12, eN22, and that pipe 111 at least partially, in particular predominantly,third useful vibrations, namely mechanical vibrations forced by the (energized) vibration exciter 31 with at least a second useful frequency fN2, namely a vibration frequency corresponding to the (alternating current) frequency of the (second) useful current component eN12 of the driver signal e1 and with a third useful phase, namely a vibration phase corresponding, in particular at least at the location of the vibration exciter 31, to the phase angle of the useful current component eN12 of the driver signal e1, and the tube 112 performs at least partially, in particular predominantly, fourth useful vibrations, namely mechanical vibrations forced by the (energized) vibration exciter 32 with the aforementioned useful frequency fN2 and with a fourth useful phase, namely a vibration phase corresponding, in particular at least at the location of the vibration exciter 32, to the phase angle of the useful current components eN22 of the driver signal e2; this in particular in the manner thatthat the fourth useful oscillations (of the tube 12) are in phase with the third useful oscillations (of the tube 11). According to a further embodiment of the invention, the measuring system electronics are further configured, in the second operating mode, to generate the driver signals e1, e2 with a second drive amplitude difference, corresponding, for example, to the aforementioned first drive amplitude difference and / or being predefinable and / or variable, namely a difference, for example also zero, between an amplitude of the useful current components eN12 of the driver signal e1 and an amplitude of the useful current components eN22 of the driver signal e2, and to feed this difference into the first or second vibration exciter. The measuring system electronics 20 can, for example, be configured to repeatedly start the second operating mode for a limited time period of more than 10 ms, in particular also more than 100 ms.

[0089] The aforementioned (alternating current) frequency of the useful current components eN12 and eN22, respectively, the third and fourth useful frequency, can, for example, be a resonance frequency of at least one of the tubes 111, 112, or, for example, a resonance frequency fr34 of a natural (parallel) vibration mode inherent in the measuring transducer, in which the two tubes 111, 112 can or do perform in-phase mechanical (resonance) vibrations, for example, in-phase bending vibrations.Accordingly, the measuring system electronics 20, according to a further embodiment of the invention, is further configured to provide the useful current component eN12 of the driver signal e1 and the useful current component eN22 of the driver signal e2, each with an (AC) frequency that deviates from a resonance frequency of at least one of the tubes 111, 112, for example, the aforementioned resonance frequency fr34, by less than 1% of that resonance frequency and / or by less than 1 Hz; this can also be achieved, for example, with a second drive phase difference of 0° or such that the third and fourth useful oscillations of the aforementioned natural parallel oscillation mode are corresponding (resonance) oscillations of the tubes 111, 112. Furthermore, the excitation arrangement (31, 32) is also configured accordingly.The first and second vibration exciters are set up to excite mechanical (resonance) vibrations of the tubes 111, 112, corresponding to the aforementioned natural parallel vibration mode, controlled by the driver signals (e1, e2).

[0090] As a result of the third and fourth useful oscillations, each oscillation signal exhibits s1, s2, s3, s4 - as also in Fig. 5 indicated - each a second (spectral) useful signal component sN12, sN22, sN32 or sN42, namely a respective sinusoidal signal component with a frequency corresponding to the second useful frequency fN2.The measuring system electronics 20 according to the invention are also configured to receive and evaluate the vibration signals s1, s2, s3, s4 in the second operating mode, namely to calibrate the measuring system on the basis of the first and third vibration signals s1, s3 and / or the second and fourth vibration signals s2, s4 received in the second operating mode, for example, on the basis of a respective amplitude of the useful signal component sN12, sN32 of the vibration signals s1, s3 and / or a respective amplitude of the useful signal component sN22, sN42 of the vibration signals s2, s4 and / or on the basis of a respective phase angle of the useful signal components sN12, sN32 of the vibration signals s1, s3 and / or a respective phase angle of the useful signal components sN22, sN42 of the vibration signals s2, s4. to check the measuring system or to detect whether there is a malfunction in the measuring system.As already mentioned, such a disturbance of the measuring system can occur, for example, due to a deposit on the inner wall of one or more of the pipes, a reduction in the wall thickness of one or more of the pipes, aging of one or more of the vibration sensors and / or vibration exciters, or incorrect assembly and / or installation of the transducer. Furthermore, such a disturbance of the measuring system can also lead to a reduction in the overall functionality of the measuring system or to a malfunction of the measuring system, for example, such that the integrity of at least one of the vibration signals s1, s2, s3, s4 or the measured values ​​obtained from them in the first operating mode is reduced, possibly to such an extent that measured values ​​obtained from at least one of the vibration signals s1, s2, s3, s4 in the first operating mode exhibit an impermissible measurement error.

[0091] According to a further embodiment of the invention, the measuring system electronics 20 are also specifically designed to detect, on the basis of at least one of the vibration signals s2, s1, s3, s4 received in the second operating mode, in particular their respective useful signal component sN11, sN21, sN31, sN41, whether a disturbance ε of the measuring system is present, for example, a disturbance that reduces the functionality of the measuring system or causes a malfunction of the measuring system and / or that reduces the integrity of at least one of the vibration signals s1, s2, s3, s4, and thus can also reduce the integrity of measured values ​​obtained from the vibration signals s1, s2, s3, s4 and / or provoke a measurement error of said measured values.This disturbance ε can, for example, significantly influence the phase angle and / or amplitude of one or more of the useful signal components sN11, sN21, sN31, sN41, such that the aforementioned phase difference Δcp12 deviates from the phase difference Δcp34 and / or a corresponding reference value by more than a previously determined tolerance. Furthermore, the measuring system electronics 20 can also be configured to issue a (fault) message, for example, declared as a (fault) alarm, if a disturbance ε of the measuring system is detected. This disturbance ε of the measuring system can, as already mentioned, occur, for example, due to a coating on the inside of the pipe wall of one or more of the pipes, a reduction in the wall thickness of one or more of the pipes, aging of one or more of the vibration sensors, and / or aging of one or more of the vibration exciters.The aforementioned disturbance ε of the measuring system can also include, in particular, a change, possibly irreversible, in one or more vibration characteristics of the pipe assembly, for example, due to a reduction in the wall thickness of one or more of the pipes, and / or due to plastic deformation of one or more of the pipes, and / or due to a coating on the inside of one or more of the pipe walls, and / or due to a crack in the pipe wall of one or more of the pipes. This is especially true if the aforementioned support structure and the pipe assembly are detachably attached to one another, as also proposed in the aforementioned WO-A 96 / 08697 or WO-A 2019 / 017891, for example, to facilitate the assembly or installation of the support structure and pipe assembly on-site at the respective measuring point.To enable the measurement system to function in its vicinity, the disturbance ε of the measuring system can, for example, include a faulty assembly of the support structure and pipe arrangement. Furthermore, the disturbance of the measuring system can also include a potentially irreversible change in one or more flow characteristics of the pipe arrangement, such as a reduction in the flow cross-section of the pipe arrangement, for example, due to a blockage of one or more of the pipes and / or due to a deposit on the inner surface of the pipe wall of one or more of the pipes, and / or a potentially irreversible change in one or more electromechanical transducer characteristics, for example, due to the aging of one or more of the vibration sensors and / or vibration exciters, and / or due to a change in a respective mechanical connection between one or more vibration sensors or one or more vibration exciters and the respective pipe.However, a disturbance of the measuring system can also be a change, possibly irreversible, of a (scale) zero point of the measuring system, which may correspond, for example, to a previously mentioned phase difference Δϕ12, Δcp34 measured with the measured substance at rest, and / or a change, possibly irreversible, of a (measurement) sensitivity of the measuring system, which may correspond to a change in the phase difference Δcp12, Δcp34 related to a change in the mass flow rate.

[0092] To check the measuring system, the measuring system electronics according to a further embodiment of the invention are further equipped to determine, on the basis of the vibration signals s1, s3 received in the second operating mode, a first (test) amplitude difference, namely a difference between an amplitude of the useful signal component sN12 of the vibration signal s1 and an amplitude of the useful signal component sN32 of the vibration signal s3 and / or a first (test) phase difference, namely a difference between a phase angle of the useful signal components sN12 of the vibration signal s1 and the useful signal components sN32 of the vibration signal s3.Alternatively or additionally, the measuring system electronics are also designed to determine a second (test) amplitude difference, namely a difference between an amplitude of the useful signal component sN22 of the vibration signal s2 and an amplitude of the useful signal component sN42 of the vibration signal s4, and / or a second (test) phase difference, namely a difference between a phase angle of the useful signal components sN22 of the vibration signal s2 and the useful signal components sN42 of the vibration signal s4, based on the vibration signals s2, s4 received in the second operating mode. According to a further embodiment of the invention, the measuring system electronics are further configured to determine at least one (modal) damping of the tubes 11, 12 for the third or third operating modes based on at least one of the driver signals e1, e2 fed in during the second operating mode and on at least one of the vibration signals s1, s2, s3, s4 received during the second operating mode.fourth useful vibrations to determine, for example, on the basis of the second useful current components eN12, eN2 at least one of the driver signals e1, e2, as well as on the basis of the useful signal components sN12, sN32 of the vibration signals s1, s3 and / or the useful signal components sN22, sN42 of the vibration signals s2, s4. Furthermore, the measuring system electronics can also be configured to compare one or more of the aforementioned measured parameters, namely at least one of the first or second (test) amplitude differences, at least one of the first or second (test) phase differences and / or at least one of the modal attenuations, with at least one associated reference value representing reduced functionality or a defect of the measuring transducer, for example, in order to issue a message, possibly also declared as a (fault) alarm, if the deviation of the respective parameter is too large, i.e., exceeding a predetermined limit.According to a further embodiment of the invention, it is also provided that the second operating mode is started or the measuring system is checked if the measuring transducer is not filled with fluid or if the measured substance is stationary within it, i.e., at a mass flow rate of zero. Alternatively or additionally, the measuring system can be checked, as also in . Fig. 5 indicated, but can also be carried out with a measuring transducer through which a fluid or the measuring substance flows, i.e. with a mass flow rate other than zero, for example also with a predetermined (known) and / or constant reference mass flow rate.

[0093] To detect the presence of a disturbance that impairs the functionality of the sensor, and thus the measurement accuracy of the measuring system, the measuring system electronics 20, according to a further embodiment of the invention, are further configured to evaluate one or more characteristic values ​​for the at least one measuring system characteristic MK1, for example, by comparing each of these values ​​with one or more reference values ​​BK1 1 (BK1 1 , BK1 2 ,...BK1 i ...) previously determined for the same measuring system characteristic MK1, for example, stored in the aforementioned non-volatile electronic data storage EEPROM. The measuring system characteristic MK1 or...A given characteristic value can, for example, characterize an operating state of the measuring system, namely quantify a system function (transfer function) inherent in the measuring system that determines one or more functional dependencies of one or more of the vibration signals s1, s2, s3, s4 on one or more of the driver signals e1, e2, or determine the functionality of the measuring system. Furthermore, the measuring system electronics 20 can also be configured to determine whether one or more characteristic values ​​for the measuring system characteristic MK1 are greater than one or more such reference values ​​for the measuring system characteristic MK1, for example, representing a measuring system that is no longer intact, and, if necessary, to output the corresponding (fault) message, for example, by displaying it locally and / or transmitting it as a status message to the aforementioned electronic data processing system.Accordingly, according to a further embodiment of the invention, the measuring system electronics are configured to calculate one or more characteristic values ​​for the at least one measuring system characteristic MK1 based on one or more of the vibration signals s1, s2, s3, s4 received in the second operating mode, such that the measuring system characteristic MK1 depends on one or more of the (system) parameters of one of the aforementioned system functions of the measuring system mediating between at least one of the second useful current components eN12, eN22 of the driver signals e1, e2 and at least one of the second useful signal components sN12, sN22, sN32, sN42 of the vibration signals s1, s2, s3, s4, for example also one of the aforementioned (modal) dampings of the tubes 111, 112 for the respective third or fourth useful vibrations and / or a ratio of one of the (modal) dampings of the tubes 111, 112 for the respective third or fourth useful vibrations. 112 for the respective third orfourth useful vibrations and a (modal) damping of the tubes 11, 12 for the respective first and / or second useful vibrations of the tubes 111, 112. The measurement system identifier MK1 can, for example, depend on a (system) amplitude ratio between a deviation Δe of the amplitude of the useful current component eN22 of the driver signal e2 from the amplitude of the useful current components eN12 of the driver signal e1 and a deviation Δs13 of the amplitude of the useful signal component sN13 of the vibration signal s3 from the amplitude of the useful signal component s12 of the vibration signal s1 and / or a deviation Δs24 of the amplitude of the useful signal component sN42 of the vibration signal s4 from the amplitude of the useful signal component sN22 of the vibration signal s2, for example also a sum Δs13+Δs24 of the same deviations, or one of the aforementioned (system) amplitude ratios Δs13 / Δe. Quantify Δs24 / Δe, Δs13 / Δe+Δs24 / Δe.The aforementioned deviations can be absolute or relative. Alternatively or additionally, the measurement system characteristic K1 can also be calculated by quantifying a (system) phase difference between the second useful signal component sN12, sN22 (at least one of the vibration measurement signals s1, s2, for example, a sum sN12+sN22 of the useful signal component sN12, sN22 of the vibration signals s1, s2) and the second useful signal component sN32, sN42 (at least one of the vibration measurement signals s3, s4, for example, a sum sN32+sN42 of the second useful signal component sN32, sN42 of the vibration signals s3, s4), for example, by quantifying one of the aforementioned (system) phase differences. The aforementioned reference values ​​for the measurement system identifier MK1 may, for example, represent a reduced functionality of the sensor (attributable to one of the aforementioned disturbances).These reference values ​​represent a malfunction of the sensor (attributable to one of the aforementioned disturbances). Such reference values ​​can be determined in advance, for example, by the manufacturer of the measuring system, during a (factory) calibration performed during the manufacturing of the measuring system, during on-site commissioning, and / or during operation of the measuring system. This can be done, for example, by first determining the respective measuring system identifier MK1 for the completed, and therefore intact, measuring system, converting it into the reference value BK1 1 using a tolerance value corresponding to a still tolerable influence, and storing it in the EEPROM data memory. The determination of the identifier values ​​MK1 and BK1 1 is then carried out by the manufacturer of the measuring system.As already indicated, the detection of a fault in the measuring system can also be automated, for example, by time-controlled operation and / or depending on changes in other diagnostic values, and can be initiated or suspended. Alternatively or additionally, the determination of the key performance indicator (KPI) values ​​can also be initiated and / or suspended externally from the measuring system, for example, from the aforementioned electronic data processing system via the aforementioned COM transmit and receive circuit and / or from on-site operating personnel via the aforementioned HMI display and control element. Accordingly, the measuring system electronics 20 are configured to determine at least the KPI values ​​for K1, if applicable.namely to receive and evaluate the start command initiating the aforementioned evaluation, namely to detect an input of the start command and then initiate a determination of the key figure values ​​for the first measurement system key figure MK1 and / or the measurement system electronics are configured to receive and evaluate a stop command that at least temporarily prevents the determination of the key figure values ​​for the measurement system key figure MK1, namely to detect an input of the stop command and then at least temporarily halt a determination of the key figure values ​​for the measurement system key figure MK1.

Claims

1. A vibronic measuring system, in particular a Coriolis mass flow meter or Coriolis mass flow / density meter, for measuring and / or monitoring at least one, in particular time-variable, flow parameter, in particular a mass flow, a volume flow and / or a flow velocity, and / or for measuring and / or monitoring at least one, in particular time-variable, substance parameter, in particular a density and / or a viscosity, of a flowing measured substance, in particular a gas, a liquid or a dispersion, said measuring system, in particular a measuring system configured as an in-line measuring device and / or measuring device with a compact design, comprising: • a measuring transducer (10) ∘ with a tube arrangement for conveying the flowing measured substance, ∘ with an exciter arrangement for converting electrical power into mechanical power serving to excite and maintain forced mechanical oscillations of the tube arrangement, ∘ and with a sensor arrangement for registering mechanical oscillations of the tube arrangement and for providing oscillation signals each representing oscillatory movements of the tube arrangement; • and measuring system electronics (20) electrically coupled to the measuring transducer (10), that is to say both to its exciter arrangement and to its sensor arrangement, in particular by means of electrical connecting cables, and formed, in particular, by means of at least one microprocessor and / or arranged in an electronics protective housing, for operating the measuring transducer and for evaluating oscillation signals delivered from the measuring transducer; • wherein the tube arrangement has ∘ a first tube (111), in particular at least sectionally bent and / or at least sectionally straight, and at least a second tube (112), in particular at least sectionally bent and / or at least sectionally straight and / or of identical structure to the first tube and / or at least sectionally parallel to the first tube, ∘ wherein each of the first and second tubes of the tube arrangement extends in each case from a respective first end of the respective tube to a respective second end of said tube with a respective tube length and has in each case a lumen surrounded by an, in particular metal, tube wall and extending in each case from the respective first end of the respective tube to the respective second end of said tube, ∘ and wherein each of the first and second tubes of the tube arrangement in each case is adapted to be flowed through by the measured substance and during that to be caused to vibrate; • wherein the exciter arrangement has two, in particular electrodynamic and / or structurally identical, oscillation exciters (31, 32) of which ∘ a first oscillation exciter (31) is mechanically connected to the first tube, in particular positioned centrally on the first tube, ∘ and a second oscillation exciter (32) is mechanically connected to the second tube, in particular positioned centrally on the second tube, • wherein each of the first and second oscillation exciters is in each case adapted to convert electrical power of a time-variable electrical current into mechanical power, in particular such that at a respective point of engagement formed by means of the respective oscillation exciter on the tube mechanically connected to it in each case, a time-variable driving force acts on the first or second tube; • wherein the sensor arrangement has at least four, in particular electrodynamic and / or structurally identical and / or spaced apart from one another, oscillation sensors, of which ∘ a first oscillation sensor (41) and a second oscillation sensor (42) are positioned spaced apart from one another, in particular symmetrically to the first oscillation exciter (31), on the first tube, that is to say, in particular, at least partially mechanically connected to the first tube, ∘ and a third oscillation sensor (43) and a fourth oscillation sensor (44) are positioned spaced apart from one another, in particular symmetrically to the second oscillation exciter (32), on the second tube, that is to say, in particular, at least partially mechanically connected to the second tube; • wherein each of the first and second oscillation sensors is in each case adapted to register oscillatory movements of the first tube and to convert them into an, in particular electrical or optical, first or second oscillation signal representing said oscillatory movements, in particular such that each of the first and second oscillation signals in each case contains one or more sinusoidal signal components with in each case a frequency corresponding to an oscillation frequency of oscillatory movements of the first tube; • wherein each of the third and fourth oscillation sensors is in each case adapted to register oscillatory movements of the second tube and to convert them into an, in particular electrical or optical, third or fourth oscillation signal representing said oscillatory movements, in particular such that each of the third and fourth oscillation signals in each case contains one or more sinusoidal signal components with in each case a frequency corresponding to an oscillation frequency of oscillatory movements of the second tube; • wherein the measuring system electronics (20) are adapted ∘ to supply electrical current to the first oscillation exciter (31), that is to say to supply an electrical first driver signal (e1) to the first oscillation exciter (31), whereby the first tube executes forced mechanical oscillations, in particular bending oscillations, with one or more oscillation frequencies predetermined by the first driver signal (e1), ∘ and to supply electrical current to the second oscillation exciter (32), that is to say to supply an electrical second driver signal (e2) to the second oscillation exciter (32) at the same time as the first driver signal (e1), whereby the second tube executes forced mechanical oscillations, in particular bending oscillations, with one or more oscillation frequencies predetermined by the second driver signal (e2), • wherein the measuring system electronics are adapted: ∘ in a first operating mode ∘ to produce both the first driver signal (e1) with at least a first useful current component (eN11), that is to say a current component that is dominating as regards a current strength or a single sinusoidal current component, with an (alternating current) frequency and a phase angle, and to supply this to the first oscillation exciter, ∘ and to produce the second driver signal (e2) with at least a first useful current component (eN21), that is to say a current component that is dominating as regards a current strength or a single sinusoidal current component, with an (alternating current) frequency corresponding to the (alternating current) frequency of the first useful current components (eN11) of the first driver signal (e1) and a phase angle that differs from the phase angle of the first useful current components (eN11) of the first driver signal (e1), in particular by 180°, and to supply this to the second oscillation exciter such ∘ that the first and second driver signals have a first drive phase difference (L1e1), that is to say a difference, in particular equal to 180°, between the phase angles of their first useful current components, ∘ that the first tube executes at least partially, in particular predominantly, first useful oscillations, that is to say mechanical oscillations forced by the first oscillation exciter (supplied with current) and with at least a first useful frequency, that is to say an oscillation frequency corresponding to the (alternating current) frequency of the first useful current component of the first driver signal, and with a first useful phase, that is to say an oscillation phase corresponding to the phase angle of the first useful current component of the first driver signal, in particular at least at the location of the first oscillation exciter, and that the second tube executes at least partially, in particular predominantly, second useful oscillations, that is to say mechanical oscillations forced by the second oscillation exciter (supplied with current) and with the first useful frequency and with a second useful phase, that is to say an oscillation phase corresponding to the phase angle of the first useful current components of the second driver signal, in particular at least at the location of the second oscillation exciter, in particular such that the second useful oscillations are opposite phase or mirror-inverted to the first useful oscillations and / or that the first and second useful oscillations are suitable for effecting Coriolis forces dependent on the mass flow in the flowing measured substance, ∘ and that each of the first, second, third and fourth oscillation signals has in each case a first useful signal component (sN11; sN21; sN31; sN41), that is to say a respective sinusoidal signal component with a frequency corresponding to the first useful frequency; • and in a second operating mode, in particular activated before and / or after the first operating mode and / or lasting for more than 10 ms and / or temporarily and / or restarted repeatedly, ∘ to produce both the first driver signal (e1) with a second useful current component (eN12), that is to say a current component that is dominating as regards a current strength or a single sinusoidal current component, with an (alternating current) frequency and a phase angle, and to supply this to the first oscillation exciter, ∘ and to produce the second driver signal (e2) with at least a second useful current component (eN22), that is to say a current component that is dominating as regards a current strength or a single sinusoidal current component, with an (alternating current) frequency corresponding to the (alternating current) frequency of the second useful current components (eN12) of the first driver signal (e1) and a phase angle that differs from the phase angle of the second useful current components (eN12) of the first driver signal (e1) by less than 180°, in particular a phase angle corresponding to the phase angle of the second useful current components (eN12) of the first driver signal (e1), and to supply this to the second oscillation exciter such ∘ that the first and second driver signals have a second drive phase difference, in particular equal to 0°, that differs, in particular by 180°, from the first drive phase difference, that is to say a difference between the phase angles of their second useful current components, ∘ that the first tube executes at least partially, in particular predominantly, third useful oscillations, that is to say mechanical oscillations forced by the first oscillation exciter (supplied with current) and with at least a second useful frequency, that is to say an oscillation frequency corresponding to the (alternating current) frequency of the second useful current component of the first driver signal and with a third useful phase, that is to say an oscillation phase corresponding to the phase angle of the second useful current component of the first driver signal, in particular at least at the location of the first oscillation exciter, and that the second tube executes at least partially, in particular predominantly, fourth useful oscillations, that is to say mechanical oscillations forced by the second oscillation exciter (supplied with current) and with the second useful frequency and with a fourth useful phase, that is to say an oscillation phase corresponding to the phase angle of the second useful current components of the second driver signal, in particular at least at the location of the second oscillation exciter, in particular such that the fourth useful oscillations are in phase with the third useful oscillations, ∘ and that each of the first, second, third and fourth oscillation signals has in each case a second useful signal component (sN12; sN22; sN32; sN42), that is to say a respective sinusoidal signal component with a frequency corresponding to the second useful frequency; • and wherein the measuring system electronics are adapted: ∘ in the first operating mode to receive and to evaluate the first, second, third and fourth oscillation signals, that is to say by reference to the oscillation signals, that is to say, in particular, at least by reference to in each case one of the useful signal components, to ascertain measured values quantifying the at least one physical measured variable (sequentially in time), ∘ and in the second operating mode to receive and to evaluate the first, second, third and fourth oscillation signals, that is to say by reference to the first and third and / or second and fourth oscillation signals received in the second operating mode, that is to say, in particular, by reference to a respective amplitude of the second useful signal component (sN12, sN32) of the first and third oscillation signals and / or a respective amplitude of the second useful signal component (sN22, sN42) of the second and fourth oscillation signals and / or by reference to a respective phase angle of the second useful signal components (sN12, sN32) of the first and third oscillation signals and / or a respective phase angle of the second useful signal components (sN22, sN42) of the second and fourth oscillation signals, to calibrate the measuring system and / or to check the measuring system or to detect whether there is a disturbance of the measuring system, in particular a disturbance lessening an ability of the measuring system to function and / or bringing about a malfunctioning of the measuring system and / or reducing an integrity of at least one of the first, second, third and fourth oscillation signals, or measured values obtained therefrom and / or provoking a measurement error of measured values obtained from at least one of the first, second, third and fourth oscillation signals, in particular a disturbance due to a deposit on an inside of the tube wall of one or more of the tubes and / or due to a reduced thickness of the tube wall of one or more of the tubes and / or due to an aging of one or more of the oscillation sensors and / or oscillation exciters and / or an incorrect installation and / or assembly of the measuring transducer.

2. The measuring system as claimed in one of the preceding claims, wherein the measuring system electronics (20) are adapted to provide the first and / or second useful current component of the first and second driver signals with an (alternating current) frequency that differs from a resonant frequency, fr1, of the first tube and / or a resonant frequency, fr2, of the second tube by less than 1% of said resonant frequency, fr1, and / or by less than 1 Hz.

3. The measuring system as claimed in one of the preceding claims, wherein the first and second tubes have at least one common resonant frequency, fr12, and wherein the measuring system electronics are adapted in the first operating mode to provide the first useful current component of the first and second driver signals in each case with an (alternating current) frequency that differs from said common resonant frequency, fr12, of the first and second tubes by less than 1% of said resonant frequency, fr12, and / or by less than 1 Hz.

4. The measuring system as claimed in one of the preceding claims, • wherein the measuring transducer has a first natural bending oscillation mode, in which the first and second tubes can execute or execute opposite phase or mirror-inverted mechanical oscillations (anti-parallel mode), and wherein the measuring system electronics are adapted in the first operating mode to supply first and second driver signals forcing said opposite phase mechanical oscillations to the first and second oscillation exciters, that is to say, in particular, to provide the first useful current components of the first and second driver signals with an (alternating current) frequency that differs from a resonant frequency, fr12, of the first natural bending oscillation mode by less than 1% of said resonant frequency and / or by less than 1 Hz, and / or with phase angles effecting a first drive phase difference of 180°; • and wherein the measuring transducer has a second natural bending oscillation mode, in particular a bending oscillation basic mode, in which the first and second tubes can execute or execute opposite phase mechanical oscillations (parallel mode), and wherein the measuring system electronics are adapted in the second operating mode to supply first and second driver signals forcing said opposite phase mechanical oscillations to the first and second oscillation exciters, that is to say, in particular, to provide the first useful current components of the first and second driver signals with an (alternating current) frequency that differs from a resonant frequency, fr22, of the second natural bending oscillation mode by less than 1% of said resonant frequency and / or by less than 1 Hz, and / or with phase angles effecting a second drive phase difference of 0°.

5. The measuring system as claimed in one of the preceding claims, wherein the measuring system electronics are adapted, by reference to at least one of the first, second, third and fourth oscillation signals received in the second operating mode, that is to say, in particular, their respective second useful signal component, to detect whether there is a disturbance of the measuring system, in particular a disturbance lessening an ability of the measuring system to function and / or bringing about a malfunctioning of the measuring system and / or reducing an integrity of at least one of the first, second, third and fourth oscillation signals, or measured values obtained therefrom and / or provoking a measurement error of measured values obtained therefrom, in particular a disturbance due to a deposit on an inside of the tube wall of one or more of the tubes and / or due to a reduced thickness of the tube wall of one or more of the tubes and / or due to an aging of one or more of the oscillation sensors and / or oscillation exciters.

6. The measuring system as claimed in one of the preceding claims, wherein each of the first useful signal components of the first, second, third and fourth oscillation signals has in each case a phase angle dependent on a mass flow of a measured substance flowing through the tube arrangement and the measuring transducer of which it forms part.

7. The measuring system as claimed in the preceding claim, wherein the measuring system electronics (20) are adapted, at least in the first operating mode, by reference to a first (measuring) phase difference, that is to say a difference between the phase angle of the first useful signal component of the first oscillation signal and the phase angle of the first useful component of the second oscillation signal and / or by reference to a second (measuring) phase difference, that is to say a difference between the phase angle of the first useful signal component of the third oscillation signal and the phase angle of the first useful signal component of the fourth oscillation signal, to ascertain, that is to say, in particular, to calculate, mass flow measured values, that is to say measured values representing the mass flow of the flowing measured substance.

8. The measuring system as claimed in claims 5 and 7, wherein the disturbance of the measuring system comprises an, in particular irreversible, change of a (scale) zero point of the measuring system corresponding to a first and / or second phase difference measured while the measured substance was stationary, and / or a (measuring) sensitivity of the measuring system corresponding to a change of the first and / or second (measuring) phase difference by reference to a change of the mass flow.

9. The measuring system as claimed in the preceding claim, • wherein the disturbance of the measuring system comprises an, in particular irreversible, change of one or more oscillation characteristics of the tube arrangement, in particular due to a reduced thickness of the tube wall of one or more of the tubes and / or due to a plastic deformation of one or more of the tubes and / or due to a deposit on an inside of the tube wall of one or more of the tubes and / or due to a crack in the tube wall of one or more of the tubes; • and / or wherein the disturbance of the measuring system comprises an, in particular irreversible, change of one or more flow characteristics of the tube arrangement, in particular due to a reduced flow cross-section of the tube arrangement, in particular as a result of a blockage of one or more of the tubes and / or as a result of a deposit on an inside of the tube wall of one or more of the tubes; • and / or wherein the disturbance of the measuring system comprises an, in particular irreversible, change of one or more electromechanical transducer properties, in particular due to an aging of one or more of the oscillation sensors and / or oscillation exciters and / or due to a change of a respective mechanical connection between one or more oscillation sensors or one or more oscillation exciters and the respective tube; • and / or wherein the disturbance of the measuring system comprises an incorrect installation and / or assembly of the measuring transducer or the measuring system of which it forms part.

10. The measuring system as claimed in one of the preceding claims, • wherein the measuring system electronics are adapted to obtain or to ascertain the respective first useful signal component, that is to say, in particular, a respective amplitude and / or a respective phase angle, from each of the first, second, third and fourth oscillation signals received in the first operating mode; and / or • wherein the measuring system electronics are adapted to obtain or to ascertain the respective second useful signal component, that is to say, in particular, a respective amplitude and / or a respective phase angle, from each of the first, second, third and fourth oscillation signals received in the second operating mode; and / or • wherein the measuring system electronics are adapted, by reference to the first and third oscillation signals received in the second operating mode, to ascertain a first (test) amplitude difference, that is to say a difference between an amplitude of the second useful signal components of the first and third oscillation signals, that is to say, in particular, to compare this with at least one reference value representing a lessened functionality or a defect of the measuring transducer or, in the case of too large a difference, that is to say a difference exceeding a reference value predetermined therefor, to output a notification, in particular declared as a (disturbance) alarm; and / or • wherein the measuring system electronics are adapted, by reference to the first and third oscillation signals received in the second operating mode, to ascertain a first (test) phase difference, that is to say a difference between a phase angle of the second useful signal components of the first and third oscillation signals, that is to say, in particular, to compare this with at least one reference value representing a lessened functionality or a defect of the measuring transducer or, in the case of too large a difference, that is to say a difference exceeding a reference value predetermined therefor, to output a notification, in particular declared as a (disturbance) alarm; and / or • wherein the measuring system electronics are adapted, by reference to the second and fourth oscillation signals received in the second operating mode, to ascertain a second (test) amplitude difference, that is to say a difference between an amplitude of the second useful signal components of the second and fourth oscillation signals, that is to say, in particular, to compare this with at least one reference value representing a lessened functionality or a defect of the measuring transducer or, in the case of too large a difference, that is to say a difference exceeding a reference value predetermined therefor, to output a notification, in particular declared as a (disturbance) alarm; and / or • wherein the measuring system electronics are adapted, by reference to the second and fourth oscillation signals received in the second operating mode, to ascertain a second (test) phase difference, that is to say a difference between a phase angle of the second useful signal components of the second and fourth oscillation signals, that is to say, in particular, to compare this with at least one reference value representing a lessened functionality or a defect of the measuring transducer or, in the case of too large a difference, that is to say a difference exceeding a reference value predetermined therefor, to output a notification, in particular declared as a (disturbance) alarm; and / or • wherein the measuring system electronics are adapted in the first operating mode to provide the first and second driver signals with an, in particular predefinable and / or adjustable, first drive amplitude difference, that is to say with a difference, in particular one equal to zero, between an amplitude of the first useful current components (eN11) of the first driver signal and an amplitude of the first useful current components (eN21) of the second driver signal and to supply this to the first or second oscillation exciter; and / or • wherein the measuring system electronics are adapted in the second operating mode to provide the first and second driver signals with a second drive amplitude difference, in particular one that corresponds to the first drive amplitude difference and / or is predefinable and / or adjustable, namely a difference, in particular equal to zero, between an amplitude of the second useful current components (eN12) of the first driver signal and an amplitude of the second useful current components (eN22) of the second driver signal, and to supply this to the first or second oscillation exciter; and / or • wherein the measuring system electronics are adapted, by reference to the first and second driver signals supplied in the second operating mode, that is to say, in particular, by reference to the second useful current components (eN12, eN2) of the first and second driver signals (e2, e2), and by reference to the first and third oscillation signals, that is to say, in particular, by reference to the second useful signal components of the first and third oscillation signals, and / or the second and fourth oscillation signals, that is to say, in particular, by reference to the second useful signal components of the second and fourth oscillation signals, to ascertain a (modal) damping of the first and second tubes for second useful oscillations, that is to say, in particular, to compare this with at least one reference value representing a lessened functionality or a defect of the measuring transducer or, in the case of too large a difference, that is to say a difference exceeding a reference value predetermined therefor, to output a notification, in particular declared as a (disturbance) alarm.

11. The measuring system as claimed in one of the preceding claims, wherein the measuring system electronics are adapted, by reference to one or more of the first, second, third and fourth oscillation signals received in the second operating mode, to calculate one or more values for at least one measuring system characterizing number (MK1) that characterizes an operating state, in particular a system function (transfer function) inherent in the measuring system and determining one or more functional dependencies of one or more of the oscillation signals of one or more of the driver signals, or determining a functionality of the measuring system, in particular such that said measuring system characterizing number is dependent on one or more parameters of a system function of the measuring system mediating between at least the second useful current components of the first and second driver signals and at least one of the second useful signal components of the first, second, third and fourth oscillation signals.

12. The measuring system as claimed in claim 11, wherein the measuring system characterizing number (MK1) depends on a system amplitude ratio between an, in particular absolute or relative, deviation (Δe) of an amplitude of the second useful current component of the second driver signal (e2) from an amplitude of the second useful current components of the first driver signal (e1) and an, in particular absolute or relative, deviation (Δs13) of an amplitude of the second useful signal component of the third oscillation signal from an amplitude of the second useful signal component of the first oscillation signal and / or an, in particular absolute or relative, deviation (Δs24) of an amplitude of the second useful signal component of the fourth oscillation signal from an amplitude of the second useful signal component of the second oscillation signal, in particular a total (Δs13+Δs24) of the deviations of the second useful signal components, that is to say, in particular, quantifies said (system) amplitude ratio (Δs13 / Δe; Δs24 / Δe; Δs13 / Δe+Δs24 / Δe).

13. The measuring system as claimed in claim 11, wherein the measuring system characterizing number (K1) is dependent on a (system) phase difference between the second useful signal component (sN12; sN22) of at least one of the first and second oscillation measurement signals, in particular a total (sN12+sN22) of the second useful signal component (sN12, sN22) of the first and second oscillation signals, and the second useful signal component (sN32; sN42) of at least one of the third and fourth oscillation measurement signals, in particular a total (sN32+sN42) of the second useful signal component of the third and fourth oscillation signals, in particular quantifies said (system) phase difference.

14. The measuring system as claimed in one of claims 11 to 13, wherein the measuring system electronics (20) are adapted to compare one or more values for the measuring system characterizing number in each case with one or more reference values ascertained for the measuring system characterizing number, in particular by the manufacturer of the measuring system and / or during manufacture and / or a start-up of the measuring system, in particular one or more reference values representing a lessened functionality of the measuring transducer and / or one or more reference values representing a malfunctioning of the measuring transducer and / or one or more reference values representing a defective measuring transducer, in particular to evaluate and / or to quantify a deviation of one or more of the characterizing number values from one or more of the reference values.

15. The measuring system as claimed in the preceding claim, wherein the measuring system electronics (20) are adapted to ascertain whether one or more values for the measuring system characterizing number (MK1) is greater than the at least one reference value for the measuring system characterizing number, that is to say, in particular, if one or more values for the measuring system characterizing number is greater than one or more reference values representing a lessened functionality of the measuring transducer and / or greater than one or more reference values representing a malfunctioning of the measuring transducer and / or greater than one or more reference values representing a no longer intact measuring transducer, to output a notification signaling this, in particular declared as a (disturbance) alarm.

16. The measuring system as claimed in one of the preceding claims, wherein the measuring system electronics (20) have a non-volatile memory (EEPROM) that is adapted to provide digital data, in particular even in the absence of operating voltage, that is to say, in particular, to store one or more previously ascertained reference values for a measuring system characterizing number.

17. The measuring system as claimed in one of claims 14 and 15, each in conjunction with claim 16, wherein there are stored in the electronic memory one or more reference values for the measuring system characterizing number, in particular previously ascertained by the manufacturer of the measuring system and / or during manufacture of the measuring system and / or during operation of the measuring system, that is to say, in particular, one or more reference values representing a lessened functionality of the measuring transducer and / or that is to say one or more reference values representing a malfunctioning of the measuring transducer.

18. The measuring system as claimed in the preceding claim, wherein the measuring system electronics (20) are adapted to compare one or more values for the measuring system characterizing number in each case with one or more reference values for the measuring system characterizing number stored in the memory.

19. The measuring system as claimed in the preceding claim, • wherein the first and second oscillation exciters (31) are mechanically connected to the support structure; and / or • wherein the first, second, third and fourth oscillation sensors are mechanically connected to the support structure.

20. The measuring system as claimed in one of the preceding claims, • wherein the first oscillation exciter is adapted to convert electrical power of a time-variable electrical current into mechanical power such that, at a point of engagement formed by means of the first oscillation exciter on the first tube mechanically connected to it, a time-variable driving force acts on the first tube; and / or • wherein the second oscillation exciter is adapted to convert electrical power of a time-variable electrical current into mechanical power such that, at a point of engagement formed by means of the second oscillation exciter on the second tube mechanically connected to it, a time-variable driving force acts on the second tube; and / or • wherein the first oscillation exciter (31) is not mechanically connected to the second tube or does not have any components that are mechanically connected to the second tube; and / or • wherein the second oscillation exciter (31) is not mechanically connected to the first tube or does not have any components that are mechanically connected to the first tube; and / or • wherein the exciter arrangement, with the exception of the first oscillation exciter, does not have any other oscillation exciters that are mechanically connected to the first tube; and / or • wherein the exciter arrangement, with the exception of the second oscillation exciter, does not have any other oscillation exciters that are mechanically connected to the second tube.