Vibronic measuring system

Abstract

The invention relates to a measuring system comprising a measuring transducer having at least one measuring tube, an exciter arrangement, a sensor arrangement and an electronic transformer circuit (US) having measurement and control electronics (DSV) and having drive electronics (EXc) connected to the measurement and control electronics and / or controlled by the measurement and control electronics. The drive electronics for its part is designed, controlled by the measurement and control electronics, to generate an electrical driver signal (e1) in a first operating mode (I) and thereby to feed electrical power into the exciter arrangement in such a manner that the at least one measuring tube executes forced mechanical vibrations at a vibration frequency predefined by the electrical drive signal at least during a first measuring interval, and in a second operating mode (II), to suspend generation of the electrical driver signal in such a manner that no electrical power is fed into the exciter arrangement by the drive electronics during said suspension.

Description

[0001] Vibronic measuring system

[0002] The invention relates to a vibronic measuring system with a vibration-type measuring transducer and an electronic converter circuit connected thereto.

[0003] In industrial measurement technology, vibronic measuring systems are often used for the highly accurate determination of a mass flow rate (mass flow) of a medium flowing in a process line, such as a pipeline, such as a liquid, a gas, or a dispersion. These systems are often formed by a converter circuit, usually formed by at least one microprocessor, and a vibration-type measuring transducer electrically connected to the converter circuit and through which the medium to be measured flows during operation. Examples of such vibronic measuring systems, for example, designed as Coriolis mass flow meters and / or density and / or viscosity meters, include:in EP-A 816 807, US-A 2002 / 0033043, US-A 2006 / 0096390, US-A 2007 / 0062309, US-A 2007 / 0119264, US-A 2008 / 0011101, US-A 2008 / 0047362, US-A 2008 / 0190195, US-A 2008 / 0250871, the.

[0004] US-A 2010 / 0005887, US-A 2010 / 0011882, US-A 2010 / 0257943, US-A 2011 / 0161017, US-A 2011 / 0178738, US-A 2011 / 0219872, US-A 2011 / 0265580,

[0005] US-A 2011 / 0271756, US-A 2012 / 0123705, US-A 2013 / 0042700, US-A 2016 / 0313162, US-A 2017 / 0261474, US-A 2020 / 0408581, US-A 44 91 009, US-A 47 56 198, US-A 47 77 833, US-A 48 01 897, US-A 48 76 898, US-A 49 96 871, the

[0006] US-A 50 09 109, US-A 52 87 754, US-A 52 91 792, US-A 53 49 872,

[0007] US-A 57 05 754, US-A 57 96 010, US-A 57 96 011, US-A 58 04 742,

[0008] US-A 58 31 178, US-A 59 45 609, US-A 59 65 824, US-A 60 06 609,

[0009] US-A 60 92 429, US-B 62 23 605, US-B 63 11 136, US-B 64 77 901 ,

[0010] US-B 65 05 518, US-B 65 13 393, US-B 66 51 513, US-B 66 66 098,

[0011] US-B 67 11 958, US-B 68 40 109, US-B 69 20 798, US-B 70 17 424,

[0012] US-B 70 40 181 , US-B 70 77 014, US-B 72 00 503, US-B 72 16 549,

[0013] US-B 72 96 484, US-B 73 25 462, US-B 73 60 451, US-B 77 92 646,

[0014] US-B 79 54 388, US-B 83 33 120, US-B 86 95 436, WO-A 00 / 19175, WO-A 00 / 34748, WO-A 01 / 02816, WO-A 01 / 71291, WO-A 02 / 060805,

[0015] WO-A 2005 / 093381, WO-A 2007 / 043996, WO-A 2008 / 013545, WO-A 2008 / 059262, WO-A 2010 / 099276, WO-A 2013 / 092104, WO-A 2014 / 151829, WO-A 2016 / 058745, WO-A 2017 / 069749, WO-A 2017 / 123214, WO-A 2017 / 143579, WO-A 85 / 05677, WO-A 88 / 02853, WO-A 89 / 00679, WO-A 94 / 21999, WO-A 95 / 03528, the

[0016] WO-A 95 / 16897, WO-A 95 / 29385, WO-A 98 / 02725, WO-A 99 / 40394 or the (unpublished) international patent application PCT / EP2021 / 083169.

[0017] The measuring transducer of each of the measuring systems shown therein comprises at least one measuring tube which is at least partially straight and / or at least partially curved, e.g. U-, V-, S-, Z- or Q-shaped, with a lumen surrounded by a tube wall for guiding the medium.

[0018] The at least one measuring tube of such a transducer is designed to carry a medium in its lumen and to be vibrated during this process, particularly in such a way that it performs useful oscillations, namely mechanical oscillations around a rest position with a useful frequency that is also determined by the density of the medium and can therefore be used as a measure of the density. In conventional measuring systems of the type in question, not least Coriolis mass flowmeters, bending oscillations at a natural resonance frequency typically serve as useful oscillations, for example, those bending oscillations that correspond to a natural fundamental bending oscillation mode inherent in the transducer, in which the oscillations of the measuring tube are such resonant oscillations that exhibit exactly one antinode.In the case of a measuring tube that is curved at least in sections, the useful vibrations are also typically designed in such a way that the measuring tube oscillates around an imaginary vibration axis that imaginarily connects an inlet and an outlet end of the measuring tube, in the manner of a cantilever clamped at one end. In contrast, in the case of measuring transducers with a straight measuring tube, the useful vibrations are usually bending vibrations in a single imaginary vibration plane. It is also known to occasionally excite at least one measuring tube to temporarily continuous forced vibrations outside of resonance, for example for the purpose of carrying out recurring checks of the measuring transducer during operation of the measuring system, or occasionally to enable free damped vibrations of at least one measuring tube and to evaluate these vibrations in each case, for example in order to, among other things,also described in the aforementioned EP-A 816 807, US-A 2011 / 0178738 or US-A 2012 / 0123705, to detect any damage to at least one measuring tube as early as possible, which could cause an undesirable reduction in the measuring accuracy and / or the operational reliability of the respective measuring system. In the case of measuring transducers with two measuring tubes, these are usually integrated into the respective process line via a distributor piece on the inlet side extending between the measuring tubes and an inlet-side connecting flange, and via a distributor piece on the outlet side extending between the measuring tubes and an outlet-side connecting flange. In the case of measuring transducers with a single measuring tube, the latter usually communicates with the process line via a connecting pipe opening into the inlet side and a connecting pipe opening into the outlet side.Furthermore, measuring transducers with a single measuring tube each comprise at least one single-piece or multi-piece counteroscillator, for example, tubular, box-shaped, or plate-shaped, which is coupled to the measuring tube on the inlet side, forming a first coupling zone, and which is coupled to the measuring tube on the outlet side, forming a second coupling zone, and which, during operation, is essentially stationary or oscillates opposite to the measuring tube. The inner part of the measuring transducer, formed by the measuring tube and counteroscillator, is usually held in a protective measuring transducer housing solely by means of the two connecting tubes through which the measuring tube communicates with the process line during operation, particularly in a manner that allows oscillations of the inner part relative to the measuring transducer housing.In the measuring transducers shown, for example, in US-A 52 91 792, US-A 57 96 010, US-A 59 45 609, US-B 70 77 014, US-A 2007 / 0119264, WO-A 01 / 02 816 or WO-A 99 / 40 394 with a single, essentially straight measuring tube, the latter and the counteroscillator are aligned essentially coaxially with one another, as is quite common in conventional measuring transducers, in that the counteroscillator is designed as an essentially straight hollow cylinder and is arranged in the measuring transducer such that the measuring tube is at least partially encased by the counteroscillator. The materials used for such counteroscillators, especially when titanium, tantalum or zirconium are used for the measuring tube, are usually comparatively inexpensive types of steel, such as structural steel or free-cutting steel.

[0019] In order to actively excite or maintain vibrations of the at least one measuring tube, not least also the aforementioned useful vibrations, measuring transducers of the vibration type further comprise an electromechanical vibration exciter which, during operation, acts differentially on the at least one measuring tube and the possibly present counter-oscillator or the possibly present other measuring tube.The vibration exciter, which is electrically connected to the aforementioned converter circuit by means of a pair of electrical connecting lines, for example in the form of connecting wires and / or conductor tracks of a flexible printed circuit board, serves in particular to convert an electrical excitation power fed in by means of the same drive signal into a driving force acting on the at least one measuring tube at an application point formed by the vibration exciter by means of an electrical drive signal provided in the converter circuit and correspondingly conditioned, namely at least adapted to changing vibration properties of the at least one measuring tube. The drive electronics are also particularly designed to adjust the drive signal by means of internal control such that it has a signal frequency corresponding to the useful frequency to be excited, which occasionally also changes over time.The drive signal can, for example, occasionally be switched off during operation of the respective measuring system, for example in order to enable the aforementioned free damped oscillations of the at least one measuring tube or, for example, as proposed in the aforementioned WO-A 2017 / 143579, in order to protect the drive electronics from overload.

[0020] Vibration exciters of commercially available vibration-type measuring transducers or vibronic measuring systems of the type in question are typically constructed in the manner of an oscillating coil operating according to the electrodynamic principle, namely by means of a coil - in the case of measuring transducers with a measuring tube and a counter-oscillator coupled to it, usually fixed to the latter - and a permanent magnet which interacts with the at least one coil and serves as an armature, which is correspondingly fixed to the measuring tube to be moved. The permanent magnet and the coil are usually aligned such that they are essentially coaxial with one another. Furthermore, in conventional measuring transducers, the vibration exciter is usually designed and positioned such that it acts essentially centrally on the at least one measuring tube. As an alternative to a vibration exciter which acts more centrally and directly on the measuring tube,in the above-mentioned US-A 60 92 429, for example also by means of two not in the center of the measuring tube, but rather fixed to the inlet or outlet side.

[0021] Vibration exciters can be used to actively excite mechanical vibrations of at least one measuring tube or, as proposed, inter alia, in US-B 62 23 605 or US-A 55 31 126, excitation arrangements formed, for example, by means of a vibration exciter acting between the possibly present counter-oscillator and the measuring transducer housing can be used.

[0022] Due to the useful vibrations of the at least one measuring tube, Coriolis forces are known to be induced in the flowing medium, which are dependent on the instantaneous mass flow rate – not least in the case where the useful vibrations of the at least one measuring tube are bending vibrations. These, in turn, can cause Coriolis vibrations with a useful frequency that are dependent on the mass flow rate and superimposed on the useful vibrations. This allows a transit time or phase difference, which is also dependent on the mass flow rate and can therefore also be used as a measure for mass flow measurement, to be detected between the inlet-side and outlet-side vibrational movements of the at least one measuring tube that performs the useful vibrations and is simultaneously flowed through by the medium.In the case of a measuring tube which is curved at least in sections and in which a vibration mode is selected for the useful vibrations in which the measuring tube is allowed to oscillate in the manner of a cantilever clamped at one end, the resulting Coriolis vibrations correspond, for example, to that bending vibration mode - occasionally also referred to as twist mode - in which the measuring tube executes torsional vibrations about an imaginary torsional vibration axis oriented perpendicular to the aforementioned imaginary vibration axis, whereas in the case of a straight measuring tube, the useful vibrations of which are designed as bending vibrations in a single imaginary vibration plane, the Coriolis vibrations are, for example, bending vibrations which are essentially coplanar with the useful vibrations.

[0023] In order to detect both inlet-side and outlet-side vibrational movements of the at least one measuring tube, not least also those corresponding to the useful vibrations, and to generate at least two electrical vibration measurement signals influenced by the mass flow rate to be measured, measuring transducers of the type in question further comprise two or more vibration sensors spaced apart from one another along the measuring tube, for example each electrically connected to one another in the aforementioned converter circuit by means of its own pair of electrical connecting lines.Each of the vibration sensors is configured to convert the aforementioned vibration movements into a vibration measurement signal representing them, which contains a useful signal component, namely a (spectral) signal component with a signal frequency corresponding to the useful frequency, and to provide this vibration measurement signal to the converter circuit, for example, namely a measuring and control electronics unit of the converter circuit formed by at least one microprocessor, for further, possibly also digital, processing. Furthermore, the at least two vibration sensors are designed and arranged such that the vibration measurement signals generated thereby not only each have a useful signal component, as already mentioned, but also that a transit time or phase difference, dependent on the mass flow rate, can be measured between the useful signal components of both vibration measurement signals.Based on this phase difference, the converter circuit or its measuring and control electronics repeatedly determines mass flow rate measured values ​​representing the mass flow rate. In addition to measuring the mass flow rate, the density and / or viscosity of the medium can also be measured—for example, based on the useful frequency and / or the electrical excitation power required to excite or maintain the useful oscillations, or the damping of the useful oscillations determined on this basis—and output by the converter circuit together with the measured mass flow rate in the form of qualified measured values. Investigations on conventional, especiallyVibronic measuring systems, each designed as a Coriolis mass flow meter, have shown that, despite a constant mass flow rate, there is occasionally a significant phase error between the aforementioned useful signal components of both vibration measurement signals, for example such that a temporal change in the phase difference can be observed which can no longer be neglected, or that the phase difference established between the same useful signal components occasionally has a fleeting, but nevertheless non-negligible, interference component which is not dependent on the mass flow rate; this applies, among other things, in applications with media which change rapidly over time in terms of density and / or viscosity or composition, in applications with inhomogeneous media, namely media which have two or more different phases, in applications with time-dependent orintermittently flowing medium or in applications where the medium is occasionally changed during the measurement, such as in filling plants or in refueling devices.

[0024] As discussed, among other things, in the aforementioned US-A 2020 / 0408581, WO-A 2017 / 069749, or US-B 79 54 388, the aforementioned phase error can result, for example, from electromagnetic coupling of the oscillation signals and the driver signal (crosstalk), for example within the converter circuit and / or within the measuring transducer. Furthermore, such a phase error can also be attributed, among other things, to the fact that the useful oscillations actively excited by the oscillation exciter are asymmetrically damped with respect to an imaginary line of action of the driving force driving the useful oscillations, such that the excited useful oscillations—especially in measuring transducers with a single oscillation exciter acting centrally on at least one measuring tube—have a disturbance component comparable to Coriolis oscillations.

[0025] In order to reduce or eliminate phase errors caused by electromagnetic coupling, the drive electronics of the measuring system shown in US-A 2020 / 0408581 are, among other things, also designed, controlled by the measuring and control electronics, to operate optionally in a first operating mode which effects the aforementioned active excitation of the useful oscillations by means of the electrical drive signal and subsequently temporarily in a second operating mode which does not supply an electrical drive signal, in such a way that at least one measuring tube (with drive electronics operating in the first operating mode) executes forced oscillations at least during a first measuring interval and (with drive electronics operating in the second operating mode) executes free damped oscillations at least during a second measuring interval.In addition, the measuring and control electronics of the measuring system shown in US-A 2020 / 0408581 are designed to determine the mass flow measured value based on the first and second vibration measuring signals received at least during a second measuring interval and no longer containing the aforementioned interference component, or on their respective phase difference which no longer contains the phase error.

[0026] One disadvantage of such a determination of mass flow measured values ​​is that the required phase angles or phase differences must be determined based on the vibration signals of the decaying free vibrations, which are actually less suitable with regard to their (signal-to-noise ratio) or their signal-to-noise ratio (SN).

[0027] Based on the aforementioned prior art, it is an object of the invention to improve vibronic measuring systems of the aforementioned type in such a way that the time-varying phase error during operation can be repeatedly determined at least approximately, in particular quantified, and / or taken into account accordingly when determining mass flow measured values.

[0028] To achieve the object, the invention consists in a vibronic measuring system, for example a Coriolis mass flow meter, which measuring system comprises:

[0029] • a measuring transducer with at least one measuring tube, with an excitation arrangement and with a sensor arrangement;

[0030] • and an electronic converter circuit which is electrically coupled to both the excitation arrangement and the sensor arrangement, for example formed by means of at least one microprocessor and / or programmable, with a measuring and control electronics and with a drive electronics which is connected to the measuring and control electronics, for example electrically, and / or controlled by the measuring and control electronics;

[0031] • wherein the measuring tube is designed to carry a fluid measuring substance, for example a gas, a liquid or a dispersion, which flows at least temporarily and is allowed to vibrate during this time;

[0032] • wherein the excitation arrangement is configured to convert electrical power fed thereto into mechanical power causing forced mechanical vibrations of the at least one measuring tube; wherein the sensor arrangement is configured to detect mechanical vibrations of the at least one measuring tube and to provide a first vibration measurement signal at least partially representing vibration movements of the at least one measuring tube and at least one second vibration measurement signal at least partially representing vibration movements of the at least one measuring tube, for example in such a way that the same first and second vibration measurement signals follow a change in a mass flow rate of the medium being conveyed in the measuring tube with a change in a phase difference, namely a change in a difference between a phase angle of the first vibration measurement signal and a phase angle of the second vibration measurement signal;

[0033] • wherein the drive electronics are configured to generate an electrical drive signal in a first operating mode and thus to feed electrical power into the excitation arrangement, such that the at least one measuring tube executes forced mechanical oscillations with at least one useful frequency, namely an oscillation frequency predetermined by the electrical drive signal, for example corresponding to a resonance frequency of the measuring transducer, and the first oscillation measurement signal has a first phase angle and the second oscillation measurement signal has a second phase angle,

[0034] • and wherein the drive electronics are configured to suspend generation of the electrical drive signal in a second operating mode such that during this time no electrical power is fed into the excitation arrangement by the drive electronics;

[0035] • wherein the measuring and control electronics are set up to control the drive electronics in such a way that the drive electronics initially operate in the first operating mode, for example temporarily and / or for longer than a reciprocal of the useful frequency and / or for more than 10 ms in each case, and at least one measuring tube (with drive electronics operating in the first operating mode) carries out forced oscillations at least during a first measuring interval, for example corresponding to more than a reciprocal of the useful frequency and / or for longer than 10 ms, and that the drive electronics then changes from the first operating mode to the second operating mode (and vice versa) or operates alternately in the first operating mode or in the second operating mode, whereby at least one measuring tube (with drive electronics operating in the second operating mode) carries out forced oscillations at least during a,for example, more than one reciprocal of the useful frequency corresponding and / or longer than 10 ms and / or less than 1 s lasting, second measuring interval, carries out free damped oscillations and the first oscillation measurement signal has a third phase angle and the second oscillation measurement signal has a fourth phase angle; • and wherein the measuring and control electronics are set up to receive and evaluate the first and second oscillation measurement signals, namely to determine one or more, for example digital, mass flow measurement values, namely the mass flow rate (of the medium carried in the at least one measuring tube), based on at least one first and second oscillation measurement signals received during one or more first measuring intervals, and to determine one or more, for example digital, mass flow measurement values, based on one or more first and second oscillation measurement signals received during one or more first and second measuring intervals,Phase error measured values ​​namely a, for example absolute or relative, (measurement) deviation of one or more first phase angles (of the first vibration measurement signal received during one or more first measuring intervals) from one or more third phase angles (of the first vibration measurement signal received during one or more second measuring intervals) and / or a, for example absolute or relative, (measurement) deviation of one or more second phase angles (of the second vibration measurement signal received during one or more first measuring intervals) from one or more fourth phase angles (of the second vibration measurement signal received during one or more second measuring intervals) and / or a, for example absolute or relative,To determine the (measurement) deviation of one or more first phase differences of the first and second vibration measurement signals received during one or more first measurement intervals from one or more second phase differences of the first and second vibration measurement signals received during one or more second measurement intervals.

[0036] Furthermore, the invention also consists in using such a measuring system for measuring and / or monitoring a fluid medium flowing at least temporarily in a pipeline, for example at least temporarily inhomogeneous and / or at least temporarily 2- or multi-phase, for example a gas, a liquid or a dispersion.

[0037] According to a first embodiment of the measuring system of the invention, it is further provided that the measuring and control electronics are set up to determine one or more mass flow measured values ​​using one or more phase error measured values, for example in such a way that the measuring and control electronics are set up to determine at least one correction value which is useful for reducing or compensating a phase error contained in the first phase differences (of the first and second vibration measurement signals received during one or more first measuring intervals) using one or more phase error measured values ​​and to take this into account when determining the mass flow measured values ​​or to calculate the mass flow measured values ​​using the at least one correction value.

[0038] According to a second embodiment of the measuring system of the invention, it is further provided that the measuring and control electronics are set up to calculate, using a plurality of phase error measured values, one or more characteristic values ​​for at least one statistical (measurement system) characteristic value, for example a position measure or a dispersion measure of a measurement value ensemble comprising several phase error measured values, for example in such a way that one or more characteristic values ​​quantify a (central) tendency of the phase error measured values ​​and / or that one or more characteristic values ​​quantify a dispersion parameter of the phase error measured values.

[0039] According to a third embodiment of the measuring system of the invention, it is further provided that one or more phase error measured values ​​represent, for example quantify, a (central) tendency, for example a mode, a median, an (empirical) mean value, of the (measurement) deviation of one or more first phase angles from one or more second phase angles.

[0040] According to a fourth embodiment of the measuring system of the invention, it is further provided that one or more phase error measured values ​​represent, for example quantify, a (central) tendency, for example a mode, a median, an (empirical) mean value, of the (measurement) deviation of one or more third phase angles from one or more fourth phase angles.

[0041] According to a fifth embodiment of the measuring system of the invention, it is further provided that one or more phase error measured values ​​represent, for example quantify, a (central) tendency, for example a mode, a median, an (empirical) mean value, of the (measurement) deviation of one or more first phase differences from one or more second phase differences.

[0042] According to a sixth embodiment of the measuring system of the invention, it is further provided that one or more phase error measured values ​​represent, for example, quantify, a dispersion parameter, for example, an (empirical) variance, an (empirical) standard deviation, or a range, of the (measurement) deviation of one or more first phase angles from one or more second phase angles. According to a seventh embodiment of the measuring system of the invention, it is further provided that one or more phase error measured values ​​represent, for example, quantify, a dispersion parameter, for example, an (empirical) variance, an (empirical) standard deviation, or a range, of the (measurement) deviation of one or more second phase angles from one or more fourth phase angles.

[0043] According to an eighth embodiment of the measuring system of the invention, it is further provided that one or more phase error measured values ​​represent, for example quantify, a scatter parameter, for example an (empirical) variance, an (empirical) standard deviation or a range, of the (measurement) deviation of one or more first phase differences from one or more second phase differences.

[0044] According to a ninth embodiment of the measuring system of the invention, it is further provided that the measuring and control electronics are configured to determine a deviation of one or more phase error measured values ​​from at least one phase error reference value, for example representing a phase error measured value determined under reference conditions and / or during a (re-)calibration of the measuring system.

[0045] According to a tenth embodiment of the measuring system of the invention, it is further provided that the measuring and control electronics are set up to compare one or more phase error measured values ​​with at least one phase error threshold value, for example one that is specific to the measuring system and / or represents a maximum permissible phase error measured value or a fault in the measuring system and / or the measured substance, for example to output a (fault) message if one or more phase error measured values ​​have exceeded at least one phase error threshold value.

[0046] According to an eleventh embodiment of the measuring system of the invention, it is further provided that the measuring and control electronics are configured to determine one or more mass flow measured values ​​based also on first and second vibration measurement signals received during one or more second measuring intervals. According to a twelfth embodiment of the measuring system of the invention, it is further provided that the measuring and control electronics are configured to determine one or more (first) phase angle measured values, for example digital, representing the first phase angle (of the first vibration measurement signal received during one or more first measuring intervals), based on first vibration measurement signals received during one or more first measuring intervals.

[0047] According to a thirteenth embodiment of the measuring system of the invention, it is further provided that the measuring and control electronics are configured to determine, based on second vibration measurement signals received during one or more first measurement intervals, one or more (second) phase angle measurement values, for example digital, representing the second phase angle (of the second vibration measurement signal received during one or more first measurement intervals).

[0048] According to a fourteenth embodiment of the measuring system of the invention, it is further provided that the measuring and control electronics are configured to determine, based on first vibration measurement signals received during one or more first measurement intervals, one or more (third) phase angle measurement values, for example digital, representing the third phase angle (of the first vibration measurement signal received during one or more second measurement intervals).

[0049] According to a fifteenth embodiment of the measuring system of the invention, it is further provided that the measuring and control electronics are configured to determine, based on second vibration measurement signals received during one or more second measurement intervals, one or more (fourth) phase angle measurement values, for example digital, representing the fourth phase angle (of the second vibration measurement signal received during one or more second measurement intervals).

[0050] According to a sixteenth embodiment of the measuring system of the invention, it is further provided that the measuring and control electronics are set up to generate one or more, for example digital, (first) phase difference measurement values ​​(X A<pi), nämlich die (erste) Phasendifferenz der (während eines oder mehreren ersten Meßintervallen empfangenen) ersten und zweiten Schwingungsmeßsignale repräsentierende Meßwerte zu ermitteln. Diese Ausgestaltung der Erfindung weiterbildend ist ferner vorgesehen, daß die Meß- und Steuerelektronik eingerichtet ist, einen oder mehrere Massestrom-Meßwerte unter Verwendung eines oder mehrere erster Phasendifferenz-Meßwerte zu ermitteln. Nach einer siebzehnten Ausgestaltung des Meßsystems der Erfindung ist ferner vorgesehen, daß die Meß- und Steuerelektronik eingerichtet ist, basierend auf während eines oder mehreren zweiten Meßintervallen empfangenen ersten und zweiten Schwingungsmeßsignalen einen oder mehrere, beispielsweise digitale, (zweite) Phasendifferenz-Meßwerte, nämlich die (zweite) Phasendifferenz der (während eines oder mehreren zweiten Meßintervallen empfangenen) ersten und zweiten Schwingungsmeßsignale repräsentierende Meßwerte zu ermitteln.Developing this embodiment of the invention, it is further provided that the measuring and control electronics are configured to determine one or more mass flow measured values ​​using one or more second phase difference measured values.

[0051] According to an eighteenth embodiment of the measuring system of the invention, it is further provided that the converter circuit, for example its measuring and control electronics, is set up, for example when the drive electronics are operating in the first operating mode or before the drive electronics are switched from the first to the second operating mode, to generate a message, for example by means of a control signal and / or to transmit it to a display element of the measuring system, which message indicates or causes the mass flow of the medium being conveyed in the at least one measuring tube to be set to a constant, for example zero, (mass flow) value.

[0052] According to a nineteenth embodiment of the measuring system of the invention, it is further provided that the converter circuit, for example namely its measuring and control electronics, is set up to effect a, for example multiple, change of the drive electronics from the first operating mode to the second operating mode (and vice versa) automatically, for example time and / or event controlled, and / or based on a control signal applied to the converter circuit, for example triggered by a (start) command transmitted thereby and / or a message transmitted thereby that the mass flow of the medium being measured in the at least one measuring tube is constant or zero.

[0053] According to a twentieth embodiment of the measuring system of the invention, it is further provided that the sensor arrangement for detecting mechanical vibrations of the at least one measuring tube comprises a first vibration sensor (51) providing the first vibration measurement signal - for example, an electrodynamic and / or inlet-side one - and a second vibration sensor providing the second vibration measurement signal - for example, an electrodynamic and / or outlet-side one and / or identical in construction to the first vibration sensor - for example, no further vibration sensor apart from the first and second vibration sensors. According to a twenty-first embodiment of the measuring system of the invention, it is further provided that the exciter arrangement for exciting vibrations of the at least one measuring tube comprises a first vibration exciter, for example, an electrodynamic and / or single one.

[0054] According to a twenty-second embodiment of the measuring system of the invention, it is further provided that the drive electronics are electrically connected to the excitation arrangement.

[0055] According to a twenty-third embodiment of the measuring system of the invention, it is further provided that the measuring and control electronics are electrically coupled to the sensor arrangement.

[0056] According to a twenty-fourth embodiment of the measuring system of the invention, it is further provided that the measuring and control electronics have a first analog-to-digital converter for the first vibration measurement signal and a second analog-to-digital converter for the second vibration measurement signal.

[0057] According to a twenty-fifth embodiment of the measuring system of the invention, the measuring and control electronics are configured to determine phase error measured values ​​(also) in the case that the measuring medium flows through the measuring transducer at a mass flow rate different from zero, for example, at least approximately constant or stationary for several successive first and second measuring intervals.

[0058] According to a first development of the measuring system of the invention, this further comprises: a display element.

[0059] According to a first embodiment of the first further development, it is further provided that the converter circuit is configured to generate control signals for the display element and to output them to the display element.

[0060] According to a second embodiment of the first development, it is further provided that the display element is configured to receive and process one or more control signals from the converter circuit, for example, to display one or more messages transmitted by means of one or more control signals. According to a second development of the measuring system of the invention, it further comprises: an operating element.

[0061] According to a first embodiment of the second further development, it is further provided that the operating element is configured to convert one or more manual inputs into one or more control signals, for example containing one or more (control) commands for the converter circuit, and to send them to the converter circuit.

[0062] According to a second embodiment of the second further development, it is further provided that the converter circuit is configured to receive and process one or more control signals from the control element, for example containing one or more (control) commands, for example to execute one or more (control) commands transmitted by means of one or more control signals.

[0063] A basic idea of ​​the invention is to occasionally suspend the active excitation of the useful oscillations required for measuring the mass flow rate during the acquisition of said useful oscillations, namely to not feed any drive signal into the excitation arrangement, whereby the coupling of the electrical excitation signal into each of the at least two oscillation signals - recognized here as a cause of the aforementioned interference components or the resulting phase error - as well as the asymmetric driving of the useful oscillations as a whole is avoided, and to determine the phase error (during operation of the measuring system) based on both the oscillation signals for the actively excited (useful) oscillations and the oscillation signals for free (damped) oscillations, for example to quantify it and / or to take the contribution of the phase error into account accordingly when determining the mass flow measured values, in particular to reduce or eliminate it.

[0064] One advantage of the invention is that established measuring transducers and converter circuits for conventional Coriolis mass flowmeters - for example, those known from the aforementioned US-B 63 11 136 or US-A 2020 / 0408581 or those offered by the applicant itself for Coriolis mass flowmeters (http: / / www.endress.com / de / messgeraete-fuer-die- prozesstechnik / produktfinder?filter.business-area=flow&filter.measuring-principle- parameter=coriolis&filter.text=) - can in principle be adopted, namely if necessary even by comparatively minor modifications of the software or firmware of the respective converter circuits, for example by appropriate retrofitting of already installed measuring systems on site. The invention and advantageous embodiments thereof are explained in more detail below with reference to exemplary embodiments illustrated in the figures of the drawing. The same orParts with the same function or functioning in the same way are provided with the same reference numerals in all figures; where clarity requires it or it otherwise seems expedient, previously mentioned reference numerals have been omitted in subsequent figures. Further advantageous embodiments or developments, in particular combinations of partial aspects of the invention initially explained only individually, will become apparent from the figures of the drawing and / or from the claims themselves.

[0065] In detail:

[0066] Fig. 1 is a vector diagram for signal components of vibration measurement signals generated by conventional Coriolis mass flow meters;

[0067] Fig. 2 a Coriolis mass flow meter, here designed as a compact measuring device;

[0068] Fig. 3 shows schematically in the form of a block diagram a converter circuit, particularly also suitable for a Coriolis mass flow meter according to Fig. 2, with a vibration-type measuring transducer connected thereto or a Coriolis mass flow meter according to Fig. 2;

[0069] Fig. 4 is a phasor diagram (phasor diagram with stationary pointers) for signal components of vibration measurement signals generated by a Coriolis mass flow meter according to Fig. 2 or by a converter circuit connected to a vibration-type transducer according to Fig. 3.

[0070] In Fig. 2 or 3, a process line (not shown here) - such as a pipeline of an industrial plant, for example a bottling plant or a

[0071] A refueling device - insertable vibronic measuring system for flowable, especially fluid or pourable, media, for example also a medium that is at least temporarily two- or multi-phase or inhomogeneous. The measuring system, designed for example as a Coriolis mass flow meter, is used in particular to measure and / or monitor a mass flow rate m or to determine mass flow measured values ​​(XM) representing the mass flow rate of a fluid medium that is guided in the aforementioned process line or is at least temporarily allowed to flow therein, for example a gas, a liquid or a dispersion. Furthermore, the measuring system can also be used to additionally determine a density p and / or a viscosity r| of the medium. According to one embodiment of the invention, the measuring system is used to determine mass flow measured values ​​of a medium to be transferred, for example with a predetermined orto use a predeterminable quantity of a measuring substance to be transferred from a supplier to a customer, for example a liquefied gas, such as a liquid gas containing methane and / or ethane and / or propane and / or butane or a liquefied natural gas (LNG) or a mixture of substances formed using liquid hydrocarbons, for example petroleum or a liquid fuel. The measuring system can accordingly also be designed, for example, as a component of a transfer point for goods transport subject to legal metrology, such as a refueling station, and / or as a component of a transfer point of the type shown in the aforementioned WO-A 02 / 060805, WO-A 2008 / 013545, WO-A 2010 / 099276, WO-A 2014 / 151829 or WO-A 2016 / 058745.

[0072] The measuring system comprises a physical-electrical measuring transducer MW which is connected to the process line via an inlet end #111 and an outlet end #112 and which is designed to be flowed through by the measuring medium during operation, as well as an electronic converter circuit US which is electrically coupled to it - in particular supplied with electrical energy during operation by means of internal energy storage and / or externally via a connecting cable.

[0073] Advantageously, the converter circuit US, which can also be programmed and / or remotely parameterized, can also be designed in such a way that, during operation of the measuring system, it can exchange measurement and / or other operating data, such as current measured values ​​or setting and / or diagnostic values ​​used to control the measuring system, with a higher-level electronic data processing system (not shown here), 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. This can include, for example, current measured values ​​or setting and / or diagnostic values ​​used to control the measuring system. Accordingly, the converter circuit US can, for example, have connection electronics which, during operation, are fed by a (central) evaluation and supply unit provided in the aforementioned data processing system and located remote from the measuring system. For example, the converter circuit US (orThe converter circuit (their aforementioned connection electronics) can be designed such that it can be electrically connected to the external electronic data processing system via a two-wire connection 2L, possibly also configured as a 4-20 mA current loop, and can thereby both draw the electrical power required for the operation of the measuring system from the aforementioned evaluation and supply unit of the data processing system and transmit measured values ​​to the data processing system, for example, by (load) modulation of a direct current supply fed by the evaluation and supply unit. Furthermore, the converter circuit US can also be designed such that it can be nominally operated with a maximum power of 1 W or less and / or is intrinsically safe.

[0074] The measuring transducer MW is a vibration-type measuring transducer, namely a measuring transducer with at least one measuring tube 10, with an excitation arrangement 41, and with a sensor arrangement (51, 52). The at least one measuring tube 10 is designed to guide the at least temporarily flowing fluid medium (or to be flowed through by the same medium) and to be vibrated at least temporarily during this time. The at least one measuring tube 10 can be housed within a transducer housing 100, together with the excitation arrangement (41) and the sensor arrangement, as well as any other components of the measuring transducer, as indicated in Fig. 3 or readily apparent from a synopsis of Figs. 2 and 3.Bei dem Meßwandler kann es sich beispielsweise auch um einen aus dem Stand der Technik, nicht zuletzt auch den eingangs erwähnten EP-A 816 807, US-A 2002 / 0033043, US-A 2006 / 0096390, US-A 2007 / 0062309, US-A 2007 / 0119264, US-A 2008 / 0011101 , US-A 2008 / 0047362, US-A 2008 / 0190195, US-A 2008 / 0250871 , US-A 2010 / 0005887, US-A 2010 / 0011882, US-A 2010 / 0257943, US-A 2011 / 0161017, US-A 2011 / 0178738, US-A 2011 / 0219872, US-A 2011 / 0265580, US-A 2011 / 0271756, US-A 2012 / 0123705, US-A 2013 / 0042700,.

[0075] US-A 2016 / 0313162, US-A 2017 / 0261474, US-A 2020 / 0408581. US-A 44 91 009, US-A 47 56 198, US-A 47 77 833, US-A 48 01 897, US-A 48 76 898, US-A 49 96 871 , US-A 50 09 109,

[0076] US-A 52 87 754, US-A 52 91 792, US-A 53 49 872, US-A 57 05 754, US-A 57 96 010,

[0077] US-A 57 96 011 , US-A 58 04 742, US-A 58 31 178, US-A 59 45 609, US-A 59 65 824,

[0078] US-A 60 06 609, US-A 60 92 429, US-B 62 23 605, US-B 63 11 136, US-B 64 77 901 ,

[0079] US-B 65 05 518, US-B 65 13 393, US-B 66 51 513, US-B 66 66 098, US-B 67 11 958,

[0080] US-B 68 40 109, US-B 69 20 798, US-B 70 17 424, US-B 70 40 181 , US-B 70 77 014,

[0081] US-B 72 00 503, US-B 72 16 549, US-B 72 96 484, US-B 73 25 462, US-B 73 60 451 ,

[0082] US-B 77 92 646, US-B 79 54 388, US-B 83 33 120, US-B 86 95 436, WO-A 00 / 19175, WO-A 00 / 34748, WO-A 01 / 02816, WO-A 01 / 71291 , WO-A 02 / 060805, WO-A 2005 / 093381 , WO-A 2007 / 043996, WO-A 2008 / 013545, WO-A 2008 / 059262, WO-A 2010 / 099276, WO-A 2013 / 092104, WO-A 2014 / 151829, WO-A 2016 / 058745, WO-A 2017 / 069749,

[0083] WO-A 2017 / 123214, WO-A 2017 / 143579, WO-A 85 / 05677, WO-A 88 / 02853, WO-A 89 / 00679, WO-A 94 / 21999, WO-A 95 / 03528, WO-A 95 / 16897, WO-A 95 / 29385, WO-A 98 / 02725,

[0084] These may be conventional vibration-type transducers known from WO-A 99 / 40 394 or PCT / EP2017 / 067826.The excitation arrangement of the measuring transducer is accordingly designed to convert electrical power fed thereto into mechanical power causing forced mechanical vibrations of the at least one measuring tube, while the sensor arrangement of the measuring transducer is designed to detect mechanical vibrations of the at least one measuring tube 10 and to provide a first vibration measurement signal s1 representing at least partially vibration movements of the at least one measuring tube, as well as at least one second vibration measurement signal s2 representing at least partially vibration movements of the at least one measuring tube; this in particular in such a way that the same vibration measurement signal corresponds to a change in the mass flow rate of the medium carried in the measuring tube with a change in at least one phase difference Acp12 (Acp12*), namely a change in at least one difference between a phase angle φ 1 of the vibration measurement signal s1 (orone of its spectral signal components) and a phase angle cp2 of the vibration measurement signal s2 (or one of its spectral signal components). Furthermore, the vibration measurement signals s1, s2 can have at least one signal frequency and / or signal amplitude dependent on the density and / or viscosity of the medium. According to a further embodiment of the invention, the sensor arrangement according to the invention comprises a first vibration sensor 51 - for example, an electrodynamic, piezoelectric, or capacitive one - attached to the inlet side of at least one measuring tube or arranged in the vicinity thereof, and a second vibration sensor 52 - for example, an electrodynamic, piezoelectric, or capacitive one - attached to the outlet side of at least one measuring tube or arranged in the vicinity thereof. As is quite common with vibration-type measuring transducers and is also shown in Fig.As indicated in Fig. 3, the vibration sensors 51, 52 can, for example, also each be positioned at the same distance from the center of the at least one measuring tube 10. Furthermore, the two vibration sensors 51, 52 can also be the only vibration sensors used to detect vibrations of the at least one measuring tube 10, such that the sensor arrangement has no further vibration sensors apart from the vibration sensors 51, 52. According to a further embodiment of the invention, the exciter arrangement is formed by means of at least one electromechanical—for example, an electrodynamic, electromagnetic, or piezoelectric—vibration exciter 41, which—as also indicated in Fig. 3—can, for example, be positioned centrally of the at least one measuring tube 10 and / or can be the only vibration exciter of the exciter arrangement or of the measuring transducer formed thereby that causes vibrations of the at least one measuring tube.Furthermore, the measuring transducer can also contain, for example, a temperature measuring arrangement 71 for detecting temperatures within the pipe arrangement and / or a strain measuring arrangement for detecting mechanical stresses within the pipe arrangement. To process the vibration measurement signals s1, s2 supplied by the measuring transducer, the converter circuit US further comprises a measuring and control electronics DSV. As schematically shown in Fig. 3, this measuring and control electronics DSV is electrically connected to the measuring transducer MW or its sensor arrangement 51, 52 and is configured to receive and evaluate the aforementioned vibration measurement signals s1, s2, namely, to determine analog and / or digital mass flow measurement values ​​representing the mass flow rate based on the at least two vibration measurement signals s1, s2, and optionally also to output them, for example in the form of digital values.The vibration measurement signals s1, s2 generated by the measuring transducer MW and fed to the converter circuit US or the measurement and control electronics DSV provided therein, for example via electrical connecting lines, can also be preprocessed there, for example, pre-amplified, filtered, and digitized. According to a further embodiment of the invention, the measurement and control electronics DSV accordingly has a first measurement signal input for the vibration measurement signal s1 and at least one second measurement signal input for the vibration measurement signal s2, and the measurement and control electronics DSV is further configured to determine the aforementioned phase difference from the same vibration measurement signals s1, s2.In addition, the measuring and control electronics DSV can also be configured to determine the respective aforementioned phase angle and / or at least one signal frequency and / or one signal amplitude from at least one of the applied vibration measurement signals s1, s2, for example, to generate, during operation, a sequence of digital phase values ​​representing the respective phase angle and / or a sequence of digital frequency values ​​representing the signal frequency and / or a sequence of digital amplitude values ​​representing the signal amplitude. According to a further embodiment of the invention, the measuring and control electronics DSV has a digital phase output and a digital amplitude output.In addition, the measuring and control electronics DSV is also designed to output an amplitude sequence, namely a sequence of digital amplitude values ​​determined on the basis of at least one of the vibration measurement signals, for example quantifying the signal amplitude of one of the vibration measurement signals, at the amplitude output, and a phase sequence, namely a sequence of digital phase values ​​determined on the basis of the vibration measurement signals, at the phase output.

[0085] The measuring and control electronics DSV can, for example, also be implemented by means of a microcomputer provided in the converter circuit US, for example realized by means of a digital signal processor DSP, and by means of program codes implemented and executed therein. The program codes can, for example, be stored persistently in a non-volatile data memory EEPROM of the microcomputer and, when the microcomputer is started, loaded into a volatile data memory RAM, for example integrated in the microcomputer. The vibration measurement signals s1, s2 are, as already indicated, to be converted into corresponding digital signals for processing in the microcomputer by means of corresponding analog-to-digital converters (A / D converters) of the measuring and control electronics DSV or the converter circuit US formed thereby; see, for example, the aforementioned US-B 63 11 136 or US-A 2011 / 0271756.Accordingly, according to a further embodiment, a first analog-to-digital converter for the first vibration measurement signal and a second analog-to-digital converter for the second vibration measurement signal are provided in the measuring and control electronics.

[0086] To control the measuring transducer, the converter circuit US, as also shown schematically in Fig. 3 in the manner of a block diagram, further comprises a drive electronics Exc which is electrically coupled to the excitation arrangement - for example, connected to the excitation arrangement via electrical connecting lines - and to the measuring and control electronics DSV - for example, via a digital bus internal to the converter circuit - or connected or electrically coupled.

[0087] The drive electronics Exc and the measuring and control electronics DSV, as well as other electronic components of the converter circuit US that serve to operate the measuring system, such as an internal power supply circuit VS for providing internal DC supply voltages and / or transmitting and receiving electronics COM that serve to communicate with a higher-level measurement data processing system or an external fieldbus, can - as is also readily apparent from a synopsis of Figs. 2 and 3 - also be housed, for example, in a corresponding electronics housing 200, in particular one that is impact- and / or explosion-proof and / or hermetically sealed. This electronics housing 200 can, for example - as also shown in Figs. 2 and 3 - be mounted on the aforementioned converter housing 100 to form a vibronic measuring system or a Coriolis mass flowmeter in a compact design.

[0088] The electrical connection of the measuring transducer MW to the converter circuit US can be established using appropriate electrical connecting cables and corresponding cable bushings. The connecting cables can be designed, at least in part, as electrical conductors, at least partially covered by electrical insulation, e.g., as twisted-pair cables, ribbon cables, and / or coaxial cables. Alternatively or additionally, the connecting cables can also be formed, at least in part, by conductor tracks on a printed circuit board, especially a flexible one, possibly coated.In order to visualize measured values ​​generated internally by the measuring system and / or status messages generated internally by the measuring system, such as an error message or an alarm, on site and / or to operate the measuring system on site, the measuring system can further comprise a display element HMI1 that communicates at least temporarily with the converter circuit US and / or an operating element HMI2 that communicates at least temporarily with the converter circuit US, such as an LCD, OLED or TFT display placed in the aforementioned electronics housing 200 behind a window provided therein, as well as a corresponding input keyboard and / or a touchscreen (as a combined display and operating element).According to a further embodiment of the invention, the control element HMI2 is configured to convert one or more manual inputs (of a user of the measuring system) into one or more control signals, for example also containing one or more (control) commands for the converter circuit US, and to send them to the converter circuit US.

[0089] Accordingly, the converter circuit US can also be configured to receive and process one or more control signals from the control element HMI2, possibly also containing one or more (control) commands, for example, namely to execute one or more (control) commands transmitted by means of one or more control signals. Alternatively or additionally, the converter circuit can also be configured to generate control signals for the aforementioned display element HMI1 and output them to the display element HMI1. In addition, the display element HMI1 can be configured accordingly to receive and process one or more control signals from the converter circuit US, for example, namely to display one or more messages transmitted by means of one or more control signals.

[0090] The drive electronics Exc of the measuring system is in particular designed to be operated temporarily in a first operating mode I and to generate in said first operating mode I an electrical drive signal e1 - for example bipolar and / or at least temporarily periodic, possibly also harmonic - and thus to feed electrical power into the excitation arrangement in such a way that the at least one measuring tube - for example also causing Coriolis forces in the medium flowing through the at least one measuring tube - carries out forced mechanical oscillations with at least one useful frequency fN, namely an oscillation frequency predetermined by the electrical drive signal e1 or a (useful) signal component E1 thereof, in particular corresponding to a resonance frequency of the measuring transducer, or that each of the oscillation measuring signals s1, s2 - as also indicated in Fig. 4, in each case a useful signal component S1* orS2*, namely a (spectral) signal component with a signal frequency corresponding to the useful frequency.

[0091] Driver signal e1 can accordingly be, for example, a harmonic electrical signal forming the aforementioned signal component E1 determining the useful frequency fN, or, for example, also an electrical signal composed of several (spectral) signal components, but nevertheless containing the aforementioned signal component E1, multi-frequency, and possibly also periodic for a predeterminable period of time. In addition, the measuring and control electronics are particularly designed to control the drive electronics Exc in such a way that the drive electronics operate in the aforementioned first operating mode I, in particular temporarily and / or for longer than a reciprocal value (1 / fN) of the useful frequency fN and / or continuously and / or repeatedly for more than 10 ms in each case, and that at least one measuring tube (with drive electronics operating in the first operating mode) at least during one, in particularperforms forced oscillations corresponding to more than a reciprocal value (1 / fN) of the useful frequency fN and / or lasting longer than 10 ms during the first measurement interval.

[0092] To set or measure the useful frequency fN, the drive electronics can, for example, have one or more phase-locked loops (PLL), as is quite common in vibronic measuring systems of the type in question or Coriolis mass flow meters. According to a further embodiment of the invention, the drive electronics Exc has a digital frequency output. Furthermore, the drive electronics Exc is also configured to output a frequency sequence, namely a sequence of digital frequency values ​​quantifying the signal frequency set for the drive signal e1, for example, the currently set useful frequency (or the signal frequency of its signal component E1), at the same frequency output.According to a further embodiment of the invention, it is further provided that the aforementioned phase output of the measuring and control electronics DSV is electrically connected to a phase input, formed, for example, by a phase comparator provided within the drive electronics Exc. This phase comparator can, for example, also be configured to detect a phase difference between the aforementioned signal component E1 of the driver signal e1 and at least one of the aforementioned useful components S1*, S2* and / or to determine the extent of this phase difference. Furthermore, the amplitude output of the measuring and control electronics DSV can also be electrically connected to an amplitude input of the drive electronics Exc that detects the amplitude of the signal component or the oscillations excited thereby in the at least one measuring tube.

[0093] The aforementioned (forced) mechanical vibrations excited by means of the drive electronics Exc and the excitation arrangement (41) connected thereto can - as is quite common in vibronic measuring systems of the type in question, not least also Coriolis mass flow meters - be, for example, bending vibrations of the at least one measuring tube 10 around an associated rest position, wherein the useful frequency fN can be set, for example, to be an instantaneous resonance frequency of a fundamental bending vibration mode of the at least one measuring tube 10 having only a single antinode, which resonance frequency also depends on the density and / or viscosity of the medium conveyed in the at least one measuring tube.

[0094] As a result of vibrations of the at least one measuring tube 10, for example the aforementioned bending vibrations, Coriolis forces can be generated in the medium flowing through the at least one measuring tube; this in particular in such a way that each of the aforementioned useful signal components S1*, S2* of the vibration measurement signals s1 and s2 each has a (spectral) measurement component S1 ' or S2' with a signal frequency corresponding to the useful frequency fN and a phase angle dependent on the mass flow rate m of the medium flowing through the measuring transducer MW (S1 ' = f(m), S2' = f(m)). Consequently, as also indicated in Fig. 4, a phase difference Acp12 (Acp12 = f(m)) dependent on the same mass flow rate m exists between the measurement component S1 ' of the vibration signal s1 and the measurement component S2' of the vibration signal s2.

[0095] The measuring and control electronics DSV is accordingly also set up to evaluate the first and second vibration measurement signals s1, s2, namely based on vibration measurement signals s1, s2 received at least during one or more of the aforementioned first measuring intervals, for example based on a corresponding first phase difference Acp12*, namely a difference between the respective phase angle cp1* of the vibration measurement signal s1 (received during one or more first measuring intervals) (or its useful signal component S1*) and the respective phase angle cp2 of the vibration measurement signal s2 (received during one or more first measuring intervals) (or useful signal component S2*), to determine one or more, for example also digital, mass flow measurement values ​​XM, namely the mass flow rate (of the medium carried in at least one measuring tube) representing measurement values.

[0096] According to a further embodiment of the invention, the measuring and control electronics are further configured to initially determine one or more, in particular digital, (first) phase difference measurement values ​​X based on vibration measurement signals s1, s2 received during one or more first measurement intervals. A(pi to determine, each of which represents the first phase difference Acp12* (of the vibration measurement signals s1, s2 received during one or more first measurement intervals), for example, to determine one or more of the aforementioned mass flow measurement values ​​XM using one or more (first) phase difference measurement values ​​X A(piAlternatively or additionally, the measuring and control electronics can be further configured to generate, based on vibration measurement signals s1 received during one or more first measuring intervals, one or more (first) phase angle measurement values ​​X, in particular digital ones, representing the first phase angle cp1* (of the vibration measurement signal s1 received during one or more first measuring intervals). <pi und / oder basierend auf während eines oder mehreren ersten Meßintervallen empfangenen Schwingungsmeßsignalen s2 einen oder mehrere den zweiten Phasenwinkel cp2* (des während eines oder mehreren ersten Meßintervallen empfangenen Schwingungsmeßsignals s2) repräsentierende, insb. digitale, (zweite) Phasenwinkel-Meßwerte X<p2 zu ermitteln. Die vorbezeichneten Phasenwinkel cp1*, cp2* bzw. Phasenwinkel-Meßwerte X<pi , X<p2 können beispielsweise in Referenz zum elektrischen Treibersignal e1 oder auch zu einem, insb.by means of the measuring and control electronics DSV or the drive electronics Exc generated, internal (clock) reference signal of the converter circuit US with a clock frequency corresponding to the useful frequency, for example as a phase difference to the useful signal component E1 of the electrical driver signal e1 or to the previously designated (clock) reference signal.

[0097] As already mentioned, when the drive electronics Exc is operating in the first operating mode or when the drive signal e1 is fed into the excitation arrangement, each of the

[0098] Vibration measurement signals s1, s2 - as also indicated in Fig. 4 or evident from a combination of Figs. 1 and 4 - in addition to the aforementioned measurement component S1' or S2', each also has an undesirable interference component S1" or S2" with the same frequency, each with a phase angle dependent on the aforementioned signal component E1 of the driver signal e1 and an amplitude likewise dependent on the same signal component E1. As also indicated in Fig. 4, the phase angles and / or the amplitudes of the interference components S1" or S2" can differ from one another. In addition, the same phase angles and amplitudes can vary during operation, for example as a result of a changing useful frequency and / or a changing amplitude of the signal component E1 or depending on the medium contained in at least one measuring tube.The aforementioned interference components can result, for example, from an electromagnetic coupling of the driver signal into the oscillation signals or from aging or (over)loading of the measuring transducer or the measuring system formed by it.

[0099] Due to the aforementioned interference components S1" and S2" contained in the vibration measurement signals s1, s2 and their useful signal components S1*, S2*, the (first) phase difference Acp12* actually measurable between the same useful signal components S1*, S2* when the drive electronics Exc is operating in the first operating mode is not solely dependent on the mass flow rate m (Acp12* = f(m, E1 )) or, conversely, the same phase difference Acp12*, as can be seen from Fig. 4, can deviate significantly from the phase difference Acp12 established between the measuring components S1', S2' (Acp12* Acp12). In other words, the vibration measurement signals s1, s2 and their

[0100] Useful signal components S1*, S2* have corresponding phase errors Err (Err ~ Acp12* - Acp12) caused by the aforementioned interference components S1" and S2" respectively.

[0101] For the earliest possible, yet reliable detection of the aforementioned interference component S1", S2" in the vibration measurement signals s1, s2 or a corresponding phase error Err of the vibration measurement signals, if necessary.also for a respective quantification and / or compensation during ongoing operation of the measuring system, the drive electronics Exc is further configured to occasionally also operate in a second operating mode during operation, for example to be switched from the aforementioned first operating mode I to the second operating mode II and to suspend generation of the electrical drive signal e1 in said second operating mode, such that during this time no electrical power is fed into the excitation arrangement by the drive electronics and that up to now, for example during the (previous) first operating mode I, forced mechanical oscillations of the at least one measuring tube are replaced by free damped oscillations; this, for example, also in such a way that the drive electronics Exc occasionally operates or alternates alternately in the first operating mode I or in the second operating mode II.changes several times from the first operating mode I to the second operating mode and back again to the first operating mode I. As can also be seen from Fig. 4, a temporary interruption or switching off of the driver signal e1 may, on the one hand, result in an amplitude (|S1**|, |S2**|) of each of the useful signal components S1**, S2** of the vibration measurement signals s1, s2 generated during the second operating mode being significantly smaller than the amplitudes (|S*11 , |S*21) of each of the useful signal components S1*, S2* detected when the drive electronics Exc is operating in the first operating mode I. On the other hand, this switching off of the driver signal e1 also leads in particular to the useful signal components S1**, S2** then not detecting the aforementioned interference components S1", S2" or only detecting them to a very limited extent due to the absence of the driver signal e1.no longer containing and thus essentially correspond to the measuring components S1', S2', so that the measurable phase difference Acp12** established between the useful signal components S1**, S2** then corresponds very precisely to the phase difference Acp12 actually required for measuring the mass flow rate m (Acp12** = Acp 12). Conversely, with knowledge of both the first phase difference Acp12* and the second phase difference Acp12**, or the respective phase angles of the useful signal components, the aforementioned

[0102] Phase errors Err (Err ~ Acp12* - Acp12**) can be at least approximately determined or quantified during operation of the measuring system. Accordingly, the measuring and control electronics DSV is also configured to occasionally, for example, time- or event-controlled, cause or induce a change of the drive electronics Exc from the first operating mode to the second operating mode (and vice versa) during operation of the measuring system, such that at least one measuring tube 10, with the drive electronics Exc in the second operating mode, executes free damped oscillations at least during a - for example, predetermined and / or adaptable - second measuring interval, and to receive the (respective) oscillation measurement signals s1, s2 during one or more second measuring intervals.In addition, the measuring and control electronics DSV of the measuring system according to the invention is also configured to evaluate the vibration measurement signals s1, s2 received during one or more first and second measuring intervals, namely to determine one or more, for example, digital, phase error measurement values ​​XEIT ZU based on these vibration measurement signals s1, s2 (received during one or more first and second measuring intervals). For this purpose, the measuring and control electronics DSV can, as already indicated, be configured, for example, to initiate the change of the drive electronics Exc from the first operating mode I to the second operating mode II or vice versa, in each case automatically, for example, time- or event-controlled.Alternatively or additionally, the measuring and control electronics DSV can also be configured to effect the aforementioned change of the drive electronics Exc from the first operating mode I to the second operating mode II based on a control signal, possibly also generated externally of the converter circuit US. This control signal can, for example, be generated by means of the aforementioned control element HMI2 or by the aforementioned data processing system (connected to the measuring system) and received via the aforementioned transmitting and receiving electronics COM. In addition, the control signal can, for example, contain a message reporting the mass flow as stationary and / or the measured material as inhomogeneous and / or a control command (directly) initiating the change from the first operating mode I to the second operating mode II.

[0103] In the measuring system according to the invention, the phase error measured values ​​XEIT are in particular those measured values ​​which represent, for example quantify, a (measurement) deviation of one or more first phase differences Acp12* (of the vibration measurement signals s1, s2 received during one or more first measuring intervals) from one or more second phase differences Acp12** of the vibration measurement signals s1, s2 received during one or more second measuring intervals.Alternatively or additionally, phase error measured values ​​XErr can also be measured values ​​that represent or quantify a (measurement) deviation of one or more first phase angles cp1* (of the vibration measurement signal s1 received during one or more first measurement intervals) from one or more third phase angles cp1** of the vibration measurement signal s1 received during one or more second measurement intervals and / or a (measurement) deviation of one or more second phase angles cp2* (of the vibration measurement signal s2 received during one or more first measurement intervals) from one or more fourth phase angles cp2** of the vibration measurement signal s2 received during one or more second measurement intervals. Furthermore, one or more phase error measured values ​​XErr can also represent or quantify a time derivative (of first and / or higher order) of at least one of the aforementioned (measurement) deviations.The aforementioned (measurement) deviation can also be, for example, an absolute or a relative (measurement) deviation. The aforementioned (third) phase angle cp1** and (fourth) phase angle cp2** can, for example, be very easily measured (just like the phase angles cp1* and cp2*, respectively) as a phase difference from the aforementioned (clock) reference signal.

[0104] The second measurement interval or the second operating mode II can advantageously be selected such that the second measurement interval and / or the second operating mode II each last longer than 10 ms (milliseconds), for example, even more than 100 ms, and / or each last longer than a reciprocal (1 / fN) of the useful frequency, for example, even longer than five times the same reciprocal. Alternatively or additionally, the second measurement interval or the second operating mode II can be selected such that they are each shorter than 1 s (second).

[0105] According to a further embodiment of the invention, the measuring and control electronics DSV is further configured to effect the change of the drive electronics Exc from the first operating mode to the second operating mode in a time-controlled manner or to carry it out in a time-controlled manner, for example in such a way that the change or, conversely, a change from the second operating mode II back to the first operating mode I takes place cyclically or in a time-controlled manner several times within a predetermined or predeterminable period of time.The measuring and control electronics and / or the drive electronics can also be set up, for example, to carry out the change of the drive electronics from the first operating mode to the second operating mode cyclically, such that the drive electronics change from the first operating mode to the second operating mode several times within a cycle and vice versa and / or that the drive electronics are predominantly operated in the first operating mode within a cycle and / or that the drive electronics are operated in the first operating mode at least as often and / or as long within a cycle as in the second operating mode.

[0106] The phase error measured values ​​XErr can also be used, for example, to check the measuring system and / or the medium being measured, for example to determine whether the measuring system is subject to a fault, possibly even an irreversible one, and / or to determine whether one or more material parameters of the medium are outside of a specified specification. Alternatively or additionally, phase error measured values ​​XE^ can also be taken into account when determining the mass flow measured values ​​XM, for example by setting up the measuring and control electronics to calculate correction values ​​that compensate for the respective phase error Err using one or more phase error measured values ​​XEIT during operation of the measuring system, or to determine one or more (future) mass flow measured values ​​XM using one or more phase error measured values ​​XEIT.

[0107] Accordingly, according to a further embodiment of the invention, the measuring and control electronics DSV is set up to use one or more phase error measurement values ​​XEIT to reduce or compensate for at least one phase error occurring in the first phase differences Acp12* (the phase difference received during one or more first measuring intervals).

[0108] Vibration measurement signals s1, s2) and to take this into account when determining the mass flow measurement values ​​XM or to calculate the mass flow measurement values ​​XM using the at least one correction value. Alternatively or additionally, the measuring and control electronics DSV can also be configured to determine one or more mass flow measurement values ​​XM based on vibration measurement signals s1, s2 received during one or more second measurement intervals. According to a further embodiment of the invention, the measuring and control electronics is therefore also configured to determine one or more, for example also digital, (second) phase difference measurement values ​​X A(p 2**, such that the same phase difference measured values ​​X A(p2** are the (second) phase difference Acp12** of the vibration measurement signals s1, s2 (received during one or more second measurement intervals). In addition, the measuring and control electronics DSV can be configured to calculate one or more mass flow measurement values ​​XM using one or more such phase difference measurement values ​​X representing the (second) phase difference Acp12**. A(p 2**. Alternatively or additionally, the measuring and control electronics DSV can also be configured to calculate one or more phase error measured values ​​XEIT based on a deviation between the first and second mass flow measured values.

[0109] Phase error measured values ​​XErr can also serve as a measure of the viscosity of the medium, or the phase error measured values ​​XEIT can be converted into viscosity measured values ​​Xr| together with a measuring system-specific (calibration) factor Kr] (Xr] ~ Kr] • XE^). The aforementioned compensation of the phase error Err, if necessary also the calculation of the aforementioned correction value used to compensate for the phase error Err, as well as the checking of the measuring system or medium, can be carried out, for example, based on statistical calculations carried out using several phase error measured values ​​XE^ determined consecutively, or using key figures of descriptive and / or inductive statistics determined for the same phase error measured values ​​XE^; this can advantageously also be done on-site, if necessary.even without interrupting the operation of the industrial plant involving the measuring system, and / or in the event that the medium flows through the measuring transducer at a mass flow rate (m > 0 and / or dm / dt « 0) which is different from zero, in particular at least approximately constant or stationary for several successive first and second measuring intervals.For this purpose, according to a further embodiment of the invention, the measuring and control electronics DSV is further configured to calculate, using a plurality of phase error measured values ​​XEIT, one or more characteristic values ​​for at least one statistical (measurement system) characteristic, for example, a position measure or a dispersion measure of a measurement value ensemble comprising several phase error measured values ​​XEIT, for example, such that one or more characteristic values ​​quantify a (central) tendency of the phase error measured values ​​XErr and / or that one or more characteristic values ​​quantify a dispersion of the phase error measured values ​​XEU around one or more of their position measures. Such a (measurement system) characteristic can each be, for example, a mode, a median, an (empirical) mean, an (empirical) variance, an (empirical) standard deviation, or a range (of the phase error measured values ​​XErr).Alternatively or in addition, one or more phase error measured values ​​XE^ can also be determined in such a way that they themselves each represent or quantify such a parameter of the (descriptive) statistics; thus, one or more phase error measured values ​​XE^ can themselves already serve as key figure values ​​for the at least one statistical (measurement system) key figure. Not least for this purpose, the measuring and control electronics can also be set up to determine one or more phase error measured values ​​XErr in such a way that they each represent or quantify a (central) tendency of the (measurement) deviation of the first phase angle cp1* from the third phase angle cp1** and / or the second phase angle cp2* from the fourth phase angle cp2** and / or the first phase difference Acp12* from the second phase difference Acp12**.quantify and / or that they each represent or quantify a measure of dispersion of the (measurement) deviation of first phase angle cp1* from second phase angles cp1** and / or second phase angle cp2* from fourth phase angles cp2** and / or first phase differences Acp12* from second phase differences Acp12**.In the aforementioned case that one or more phase error measured values ​​XErr are calculated by means of the measuring and control electronics DSV based on a deviation between first and second mass flow measured values, one of the phase error measured values ​​XErr can also represent a difference between a first mass flow measured value and a second mass flow measured value determined immediately before or after it and / or a position measure for a plurality of such differences between first and second mass flow measured values ​​and / or a difference between position measures determined for a plurality of first and second mass flow measured values ​​and / or a dispersion measure for a plurality of such differences between first and second mass flow measured values ​​and / or a difference between dispersion measures determined for a plurality of first and second mass flow measured values.

[0110] A check of the measuring system or medium, for example on site or during ongoing operation of the respective system, can also be carried out by comparing one or more phase error measured values ​​XErr with one or more (phase error) reference values ​​or (phase error) threshold values; this can be done, for example, in such a way that phase error measured values ​​XE^ which represent rapidly varying and / or strongly fluctuating or merely temporary measurement deviations or which exceed a predetermined level are evaluated as an indicator of a disturbance in the medium, for example in the form of a multi-phase flow and / or due to foreign substances entrained in the medium, and / or in such a way that phase error measured values ​​XErr which represent slowly and / or continuously increasing measurement deviations or which exceed a predetermined level are evaluated as an indicator representing a disturbance in the measuring transducer.

[0111] Accordingly, according to a further embodiment of the invention, the measuring and control electronics DSV is further configured to determine a deviation of one or more phase error measured values ​​XErr from at least one associated phase error reference value, for example representing a phase error measured value XE^ determined (in advance) under reference conditions and / or during a (re-)calibration of the measuring system, and / or to compare one or more phase error measured values ​​XE^ with at least one (measuring system-specific) phase error threshold value, for example representing a maximum permissible phase error measured value XErr, MAX or a disturbance of the measuring system and / or the measured substance.In addition, the measuring and control electronics DSV can also be configured to output a corresponding (fault) message, for example, also via the aforementioned display element HMI1, if one or more phase error measured values ​​XErr have exceeded the aforementioned at least one phase error threshold value. The aforementioned phase error reference values ​​or phase error threshold values ​​can be determined at least partially, for example, by the manufacturer (ex works) and / or during on-site calibration of the measuring system (under reference conditions), possibly also on a recurring basis, and stored accordingly in the converter circuit, for example, in a non-volatile (data) memory of the converter circuit US, such as the aforementioned non-volatile data memory EEPROM.

[0112] Although, as already mentioned, the determination of the phase error Err can also be carried out when the medium flows through the measuring transducer at a mass flow other than zero, it can be advantageous, not least when the measuring system is used in a plant or a process with a (highly) dynamic mass flow, such that the respective medium regularly has a non-stationary and / or highly temporally changing mass flow rate, to introduce or provide a mass flow in the plant that is as stationary as possible or at most slightly fluctuating, or conversely to report such a stationary mass flow to the measuring system, at least for a short period of time required to determine the phase error measured value XEIT. For this purpose, the measuring and control electronics or the converter circuit US formed thereby are further configured according to a further embodiment of the invention (with drive electronics Exc or operating in the first operating mode I).before switching the drive electronics Exc from the first to the second operating mode), to generate a message, for example, namely to output it by means of the aforementioned control signal and / or to transmit it to the aforementioned display element HMI1, which indicates or causes the mass flow of the medium carried in the at least one measuring tube to be set to a constant, for example, zero, (mass flow) value. Alternatively or additionally, the measuring and control electronics DSV or the converter circuit US formed thereby can also be set up, based on a control signal applied to the converter circuit US, for example, triggered by a (start) command transmitted thereby and / or a message transmitted thereby that the mass flow of the medium carried in the at least one measuring tube is constant or zero, to generate a, if necessaryto cause the drive electronics to change from the first operating mode to the second operating mode (and vice versa), even multiple times.

Claims

PATENT CLAIMS 1. Vibronal measuring system, in particular Coriolis mass flow meter, comprising: - a measuring transducer - with at least one measuring tube, - with a pathogen arrangement - and with a sensor array; - as well as an electronic converter circuit (US) electrically coupled to both the excitation arrangement and the sensor arrangement, in particular formed by means of at least one microprocessor and / or programmable - with a measurement and control electronics (DSV) - and with drive electronics (Exc) connected to the measurement and control electronics, especially electrically, and / or controlled by the measurement and control electronics; - wherein the measuring tube is set up to guide a fluid measuring substance, in particular a gas, a liquid or a dispersion, which flows at least intermittently, and is vibrated during this time; - wherein the excitation arrangement is configured to convert electrical power fed into it into forced mechanical vibrations of the at least one measuring tube; - wherein the sensor arrangement is configured to detect mechanical vibrations of the at least one measuring tube and to provide a first vibration measurement signal (s1) representing at least a portion of the vibration movements of the at least one measuring tube, as well as at least a second vibration measurement signal (s2) representing at least a portion of the vibration movements of the at least one measuring tube, in particular such that the same first and second vibration measurement signals follow a change in the mass flow rate of the medium guided in the measuring tube with a change in a phase difference, namely a change in the difference between a phase angle of the first vibration measurement signal and a phase angle of the second vibration measurement signal; - wherein the drive electronics (Exc) are configured to generate an electrical driver signal (e1) in a first operating mode (I) and thereby feed electrical power into the excitation arrangement, such that - that at least one measuring tube performs forced mechanical vibrations with at least one useful frequency, namely a vibration frequency specified by the electrical driver signal, in particular corresponding to a resonance frequency of the measuring transducer - and the first vibration measurement signal (s1) has a first phase angle and the second vibration measurement signal (s2) has a second phase angle, - and where the drive electronics (Exc) are set up, - in a second operating mode (II) to suspend the generation of the electrical driver signal, such that no electrical power is fed into the excitation arrangement by the drive electronics (Exc) during this time; - wherein the measuring and control electronics (DSV) is configured to control the drive electronics in such a way, - that the drive electronics, in particular temporarily and / or for longer than a reciprocal of the operating frequency and / or lasting more than 10 ms each time, initially operate in the first operating mode and that at least one measuring tube (with drive electronics operating in the first operating mode) performs forced oscillations at least during a first measurement interval, in particular corresponding to more than a reciprocal of the operating frequency and / or lasting longer than 10 ms, - and that the drive electronics subsequently switch from the first operating mode (I) to the second operating mode (II) (and vice versa) or operate alternately in the first operating mode (I) or in the second operating mode (II), whereby at least one measuring tube (with drive electronics operating in the second operating mode) performs free damped oscillations at least during a second measurement interval, in particular one that corresponds to more than a reciprocal of the operating frequency and / or lasts longer than 10 ms and / or less than 1 s, and that the first oscillation measurement signal (s1) has a third phase angle and the second oscillation measurement signal (s2) has a fourth phase angle; - and wherein the measuring and control electronics are set up to receive and evaluate the first and second vibration measurement signals, namely - to determine one or more mass flow measurement values ​​(XM), in particular digital ones, representing the mass flow rate (of the substance being measured in at least one measuring tube), based on first and second vibration measurement signals received at least during one or more first measurement intervals, - as well as based on one or more, in particular digital, phase error measurement values ​​(XEIT) received during one or more first and second measurement intervals, namely a, in particular absolute or relative, (measurement) deviation of one or more first phase angles (of the first vibration measurement signal received during one or more first measurement intervals) from one or more third phase angles (of the first vibration measurement signal received during one or more second measurement intervals) and / or a, in particular absolute or relative, (measurement) deviation of one or more second phase angles (of the second vibration measurement signal received during one or more first measurement intervals) from one or more fourth phase angles (of the second vibration measurement signal received during one or more second measurement intervals) and / or a, in particularto determine absolute or relative (measurement) deviations of one or more first phase differences of the first and second vibration measurement signals received during one or more first measurement intervals from one or more second phase differences of the first and second vibration measurement signals received during one or more second measurement intervals.

2. Measuring system according to one of the preceding claims, - wherein the measuring and control electronics are configured to determine one or more mass current measurements (XM) using one or more phase error measurements (XEIT), in particular such that the measuring and control electronics are configured to determine, using one or more phase error measurements (XEIT), at least one correction value suitable for reducing or compensating a phase error contained in the first phase differences (of the first and second vibration measurement signals received during one or more first measurement intervals) and to take this correction value into account when determining the mass current measurements (XM) or to calculate the mass current measurements (XM) using the at least one correction value; and / or - wherein the measuring and control electronics are configured to calculate, using a plurality of phase error measurements (XEIT), one or more key figure values ​​for at least one statistical (measuring system) key figure, in particular a measure of location or a measure of dispersion of a set of measurements comprising several phase error measurements (XEIT), in particular such that one or more key figure values ​​indicate a (central) trend of the phase error measurements (XEIT) quantify and / or that one or more key figure values ​​quantify a dispersion parameter of the phase error measurements (XEIT).

3. Measuring system according to one of the preceding claims, - wherein one or more phase error measurements (XErr) represent, in particular quantify, a (central) tendency, in particular a mode, a median, an (empirical) mean, of the (measured) deviation of one or more first phase angles from one or more second phase angles; and / or - wherein one or more phase error measurements (XE^) represent, in particular quantify, a (central) tendency, in particular a mode, a median, an (empirical) mean, of the (measured) deviation of one or more third phase angles from one or more fourth phase angles; and / or - wherein one or more phase error measurements (XE^) represent, in particular quantify, a (central) tendency, in particular a mode, a median, an (empirical) mean, of the (measured) deviation of one or more first phase differences from one or more second phase differences; and / or - wherein one or more phase error measurements (XE^) represent, in particular quantify, a dispersion parameter, in particular an (empirical) variance, an (empirical) standard deviation or a range, of the (measurement) deviation of one or more first phase angles from one or more second phase angles; and / or - wherein one or more phase error measurements (XE^) represent, in particular quantify, a dispersion parameter, in particular an (empirical) variance, an (empirical) standard deviation or a range, of the (measurement) deviation of one or more second phase angles from one or more fourth phase angles; and / or - where one or more phase error measurements (XE^) represent, in particular quantify, a dispersion parameter, in particular an (empirical) variance, an (empirical) standard deviation or a range, of the (measurement) deviation of one or more first phase differences from one or more second phase differences.

4. Measuring system according to one of the preceding claims, - wherein the measuring and control electronics are configured to determine a deviation of one or more phase error measured values ​​(XE^) from at least one phase error reference value, in particular a phase error measured value (XE^) determined under reference conditions and / or during a (re-)calibration of the measuring system; and / or - wherein the measuring and control electronics are set up to measure one or more phase error values ​​(XE^) with at least one, in particular measuring system specific and / or a maximum permissible phase error value (XErr, MAX) or a disturbance of the measuring system and / or the phase error threshold representing the measured substance, in particular to issue a (fault) message if one or more Phase error EIT (XEIT) measurements showed that very few exceeded a phase error threshold.

5. Measuring system according to one of the preceding claims, wherein the measuring and control electronics are configured to determine one or more mass current measurement values ​​(XM) based also on first and second vibration measurement signals received during one or more second measurement intervals.

6. Measuring system according to one of the preceding claims, wherein the measuring and control electronics are configured, based on first vibration measurement signals received during one or more first measurement intervals, to generate one or more, in particular digital, (first) phase angle measurement values ​​(X) representing the first phase angle (of the first vibration measurement signal received during one or more first measurement intervals). <pi) zu ermitteln.

7. Measuring system according to one of the preceding claims, wherein the measuring and control electronics are configured to determine, based on second vibration measurement signals received during one or more first measurement intervals, one or more, in particular digital, (second) phase angle measurement values ​​(X^) representing the second phase angle (of the second vibration measurement signal received during one or more first measurement intervals).

8. Measuring system according to one of the preceding claims, wherein the measuring and control electronics are configured to determine, based on first vibration measurement signals received during one or more first measurement intervals, one or more (third) phase angle measurement values ​​(X^) representing the third phase angle (of the first vibration measurement signal received during one or more second measurement intervals), in particular digital (third) phase angle measurement values ​​(X^).

9. Measuring system according to one of the preceding claims, wherein the measuring and control electronics are configured to determine, based on second vibration measurement signals received during one or more second measurement intervals, one or more, in particular digital, (fourth) phase angle measurement values ​​(X^) representing the fourth phase angle (of the second vibration measurement signal received during one or more second measurement intervals).

10. Measuring system according to one of the preceding claims, wherein the measuring and control electronics are configured to generate one or more, in particular digital, (first) phase difference measured values ​​(X) based on first and second vibration measurement signals received during one or more first measurement intervals. A <pi), nämlich die (erste) Phasendifferenz der (während eines oder mehreren ersten Meßintervallen empfangenen) ersten und zweiten Schwingungsmeßsignale repräsentierende Meßwerte zu ermitteln.

11. Measuring system according to the preceding claim, wherein the measuring and control electronics are configured to measure one or more mass current measurements (XM) using one or more first phase difference measurements (X A(p i) to determine.

12. Measuring system according to one of the preceding claims, wherein the measuring and control electronics are configured to generate one or more, in particular digital, (second) phase difference measured values ​​(X) based on first and second vibration measurement signals received during one or more second measurement intervals. A(p 2) namely to determine the (second) phase difference of the first and second vibration measurement signals (received during one or more second measurement intervals).

13. Measuring system according to the preceding claim, wherein the measuring and control electronics are configured to measure one or more mass current measurements (XM) using one or more second phase difference measurements (X A(p2) to determine.

14. Measuring system according to one of the preceding claims, - wherein the converter circuit, in particular its measuring and control electronics, is configured, in particular when the drive electronics are operating in the first operating mode or before switching the drive electronics from the first to the second operating mode, to generate a message, in particular to output a control signal and / or to transmit it to a display element of the measuring system, which indicates or causes the mass flow of the medium guided in at least one measuring tube to be set to a constant, in particular zero, (mass flow) value; and / or - wherein the converter circuit, in particular its measuring and control electronics, is set up to be automatically controlled, in particular by time and / or event, and / or based on a control signal applied to the converter circuit, in particular triggered by a (start) command transmitted therein and / or a message transmitted therein indicating that the mass flow of the medium guided in at least one measuring tube is constant or zero, to effect a, in particular multiple, change of the drive electronics from the first operating mode to the second operating mode (and vice versa).

15. Measuring system according to one of the preceding claims, further comprising: a display element (HMI1).

16. Measuring system according to the preceding claim, - wherein the converter circuit is configured to generate control signals for the display element (HMI1) and output them to the display element (HM11); and / or - wherein the display element (H Ml 1 ) is configured to receive and process one or more control signals from the converter circuit, in particular to display one or more messages transmitted by means of one or more control signals.

17. Measuring system according to one of the preceding claims, further comprising: an operating element (HMI2).

18. Measuring system according to the preceding claim, - wherein the control element (HMI2) is configured to convert one or more manual inputs into one or more control signals, in particular containing one or more (control) commands for the converter circuit, and send them to the converter circuit; and / or - wherein the converter circuit is configured to receive and process one or more control signals from the operating element (HMI2), in particular containing one or more (control) commands, and in particular to execute one or more (control) commands transmitted by means of one or more control signals.

19. Measuring system according to one of the preceding claims, - wherein the sensor arrangement for detecting mechanical vibrations of the at least one measuring tube comprises a first vibration sensor (51) providing the first vibration measurement signal – in particular electrodynamic and / or inlet-side – and a second vibration sensor (52) providing the second vibration measurement signal – in particular electrodynamic and / or outlet-side and / or identical in construction to the first vibration sensor, in particular namely no further vibration sensor apart from the first and second vibration sensors; and / or - wherein the excitation arrangement for exciting vibrations of the at least one measuring tube comprises a first vibration exciter (41), in particular an electrodynamic and / or single first vibration exciter; and / or - wherein the drive electronics are electrically connected to the excitation arrangement; and / or - wherein the measuring and control electronics are electrically coupled to the sensor arrangement; and / or - wherein the measuring and control electronics comprise a first analog-to-digital converter for the first vibration measurement signal and a second analog-to-digital converter for the second vibration measurement signal.

20. Measuring system according to one of the preceding claims, wherein the measuring and control electronics are configured to determine phase error measurement values ​​(XEIT) (also) in the case that a mass flow rate of non-zero mass flowing through the measuring transducer is at least approximately constant or stationary for several successive first and second measurement intervals.

21. Use of a measuring system according to one of the preceding claims for measuring and / or monitoring a fluid substance flowing at least temporarily in a pipeline, in particular a fluid substance that is at least temporarily inhomogeneous and / or at least temporarily two-phase or multi-phase, in particular a gas, a liquid or a dispersion.

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