RU2320964C2 - Device for measuring physical parameters - Google Patents

Abstract

FIELD: invention is assigned for measuring mass consumption, density, viscosity and pressure of medium containing in reservoir or in flow along pipeline.

SUBSTANCE: device has sensor of vibration types and electronic block connected with sensor. Sensor arrangement of sensor has first and second sensor elements for giving measuring signals (S_1, S₂) and first and second temperature sensors for giving temperature measuring signal (θ₁,θ₂). Using measuring signal (S₁) and meaning (K₁) of correction for measuring signal (S₁), electronic block works measuring meaning (X) presenting physical parameter. At that electronic block calculates meaning (K₁) of correction with aid of temporary characteristic of temperature signal (θ₁) taking into consideration meanings of temperature registered before that by temperature sensor. Invention provides good compensation in measuring signal of temperature mistake in unadjusted transitional field of distribution of temperature inside sensor at using of only small number of temperature sensors.

EFFECT: measures mass consumption, density, viscosity or pressure of medium.

23 cl, 8 dwg

Description

The invention relates to a measuring device for measuring at least one physical process parameter, in particular mass flow, density, viscosity, pressure, etc. medium contained in the tank or flowing through the pipeline.

In industrial measurement technology, in particular also in connection with the automation of chemical or technological processes, in order to generate on-site analog or digital signals of measured values representing process parameters, measuring devices installed near the process, so-called field measuring devices, are used. Examples of similar processes known to those skilled in the art and per se are described in detail in EP-A 984248, EP-A 1158289, US-A 3878725, US-A 4308754, US-A 4468971, US-A 4524610, US-A 4574328, US-A 4594584, US-A 4617607, US-A 4716770, US-A 4768384, US-A 4850213, US-A 5052230, US-A 5131279, US-A 5231884, US-A 5359881, US-A 5363341, US-A 5469748, US-A 5604685, US-A 5687100, US-A 5796011, US-A 6006609, US-B 6236322, US-B 6352000, US-B 6397683, WO-A 8802476, WO-A 8802853, WO-A 9516897, WO-A 0036379, WO-A 0014485, WO-A 0102816 or WO-A 02086426.

Recorded process parameters may be, for example, mass flow rate, density, viscosity, level or limit level, pressure or temperature, and the like. liquid, powder, vapor or gaseous medium flowing or stored in an appropriate tank, such as a pipe or tank.

To register the corresponding process parameters, the measuring device contains a corresponding, for the most part physico-electric sensor, which is mounted in the wall of the tank-guiding medium or in the piping-guiding medium and serves to generate at least one, in particular an electric, measuring signal, as much as possible accurately representing the initially recorded process parameter. To this end, the sensor is connected to a corresponding electronic unit of the measuring device, which also serves, in particular, to process or evaluate at least one measuring signal.

In addition, measuring devices of the described kind are connected via a data transmission system connected to the electronic unit of the measuring device to each other and / or to the corresponding process control modules of the VM, where they, for example, are transmitted via a current loop (4-20 mA) and / or a digital data bus signals of measured values. Serial fieldbus systems such as Profibus-A, Foundation Fieldbus, as well as the corresponding transmission protocols, are used as data transmission systems. Using VM process controls, the transmitted measured value signals can be processed and displayed in the form of corresponding measurement results, for example, on monitors and / or converted into control signals for process executive organs, for example, electromagnetic valves, electric motors, etc.

To accommodate the electronic unit of the measuring device, such measuring devices further comprise a housing, which, as proposed, for example, in US-A 6397683 or WO-A 0036379, can be located far from the field measuring device and connected to it only by a flexible wire or which as disclosed, for example, in EP-A 903651 or EP-A 1008836, is located directly on the sensor or separately housing the sensor. Often, the housing of the electronic unit serves then, as described, for example, in EP-A 984248, US-A 4594584, US-A 4716770 or US-A 6352000, also to accommodate some mechanical components of the sensor, for example, deformable when operating under mechanical action of the membrane -, rod-, sleeve- or tube-shaped deformation or vibrating bodies (US-A 6352000).

In particular, in EP-A 1158289, US-A 4768384, US-A 5359881, US-A 5687100, WO-A 8802476, WO-A 9516897 or WO-A 0102816 described measuring instruments for measuring at least one physical process parameter, in particular mass flow rate, density, viscosity, pressure, etc., flowing through a pipeline medium, in which the sensor contains:

- at least one measuring tube, which guides the flowing, in particular forced to flow the medium;

- an excitation device electrically connected to the electronic unit of the measuring device with a mechanical action on the measuring tube, in particular an electrodynamic or electromagnetic oscillation exciter for driving the measuring tube;

- a sensing device that generates measuring signals, which contains at least one that primarily responds to the physical parameter of the process, in particular also to changes in the parameter, the first and second sensor elements and, through the sensor elements, supplies at least one first, which is influenced physical parameter of the process, and second measuring signals;

- moreover, the electronic unit of the measuring device delivers at least one excitation signal serving to control the exciter, causing the measuring tube to vibrate at least temporarily during operation;

- moreover, both sensor elements respond to vibration of the measuring tube from the input and output sides;

- moreover, the measuring signals supplied by the sensor elements represent the mechanical vibrations of the vibrating measuring tube exposed to the medium.

In addition, such a vibration-type measuring device includes a measuring tube with vibration exciters and sensors located on it, as well as possible additional components of a housing sensor.

If the measuring device of the vibration type is used as a Coriolis mass flow meter, the electronic unit of the measuring device determines, among other things, the phase difference between the two sensor elements supplied by the measuring signals, here oscillation signals, and generates a measured value signal at its output, which in accordance with the time characteristic of the phase difference represents the measured value of the mass flow rate.

As you know, measuring instruments of the described type, in particular their respective sensor, in addition to the above described, initially recorded process parameters can also be affected by other physical parameters, in particular not influenced, in particular the temperature of the process or the environment.

In particular, for measuring instruments working with vibrating measuring tubes, for example Coriolis mass flow meters, densitometers and / or viscometers, the thermally caused variable expansion of the measuring tube can also lead to the fact that the sensor, in addition to sensitivity to the primary measured parameters, for example mass flow, density and / or viscosity, will also have a transverse sensitivity to the currently prevailing temperature distribution in the sensor. Due to such temperature-related parasitic influences on the oscillatory characteristic of the sensor, it is practically upset. Therefore, the measuring signal supplied by the electronic unit of the measuring device may be erroneous if this “detuning” is not taken into account.

To compensate for temperature-related parasitic influences on the measuring signals supplied by the sensor and / or on the signals of the measured values from Coriolis mass flow meters or Coriolis mass flow meters / densitometers derived from them by the electronic unit of the measuring device, at least one temperature sensor is usually also provided, for example, to measure the temperature of a measuring tube or surrounding a measuring tube in a sensor device space (US-A 5359881, US-A 5687100 or WO-A 8802476).

In the measuring instruments described here, in order to compensate for the temperature effects on the elastic moduli of the respective measuring tubes by means of a temperature sensor placed on a bent measuring tube, for example Pt100, Pt1000 or a thermocouple, an electric temperature measuring signal corresponding to the temperature of the medium to be measured is first generated. Then, in the electronic unit of the measuring device, by multiplying by constant, time-invariant coefficients, the correction coefficient is taken into account, taking into account the influence of the measured temperature on the elastic modulus, and, thus, introduced into the correction of the measured value signal, for example, the mass flow signal and / or density signal. To smooth the temperature measurement signal or to improve the signal-to-noise ratio, appropriate digital signal filters can be used, as suggested, for example, in WO-A 8802476.

In addition to such vibration-type measuring instruments with a bent measuring tube, the specialist further knows vibration-type measuring devices with one straight measuring tube or with two measuring tubes (US-A 4524610, US-A 4768384, US-A 6006609, WO-A 00144485 or WO-A 0102816). For such measuring instruments with one straight measuring tube, the sensor usually has a carrier element suspended in its housing with the possibility of oscillation, fixed on the measuring tube to hold the vibration pathogen and sensor elements, which also serves to unblock, from the point of view of the vibration technique, a vibrating measuring tube from the connected pipeline. The supporting element can be made, for example, in the form of a tubular compensation cylinder or a box-shaped supporting frame located coaxially with the measuring tube.

Due to their special design, vibration-type measuring instruments with a direct measuring tube or direct measuring tubes react to temperature changes not only with the already mentioned change in the elastic modulus, but also cause temperature-related changes in mechanical stresses inside the measuring tube and, possibly, also inside the supporting element and / or sensor housing changes in the sensitivity of the sensor to the primary process parameters.

Such mechanical stresses caused by temperature, in particular, voltages acting coaxially with the measuring tube, can have various causes that can occur individually or in combination with each other. Even if the measuring tube and the supporting element or the sensor body have basically the same temperature, temperature-dependent mechanical stresses can occur if the supporting tube and the oscillating system are composed of different materials with different coefficients of thermal expansion. Such temperature effects even more strongly affect the measurement result if the temperature of the measuring tube differs from the temperature of the carrier pipe. This happens, in particular, when it is necessary to measure the process medium, the temperature of which differs from the ambient temperature. In very hot or very cold environments, a very large temperature difference can occur between the carrier or sensor housing and the measuring tubes.

To compensate also for such temperature-sensitive sensors that change the sensitivity of the sensor to the primary process parameters, for example, US-A 4768384, US-A 5231884 or WO-A 0102816 describe measures taken for this purpose. At the same time, using at least one additional temperature sensor located on the sensor housing, the influence of temperature-dependent extensions or voltages of the sensor housing on the measured value signal is compensated due to the fact that an additional correction factor is taken into account in the electronic unit of the measuring device, taking into account the influence of the measured temperature on the expansion or distribution of stresses in the sensor, and include it in the measured value signal. To form this correction coefficient, each of the temperature signals is simultaneously and without delay multiplied by constant coefficients and, if necessary, also by itself.

It turned out, however, that the temperature distribution during the operation of measuring instruments of the described kind, on the one hand, in particular, due to a constant medium temperature that is not supported in most cases, can be subject to significant fluctuations, and, therefore, inside the measuring device, In particular, also inside the sensor, dynamic compensation processes regarding temperature distribution are re-noted. On the other hand, these temporary changes in the temperature distribution, due to different specific thermal diffusivities or heat capacities of individual sensor components, for example a measuring tube or sensor housing, can quickly act on different individual sensor components determining the sensitivity of the sensor, so that temperature profiles or gradients recorded two or more temperature sensors can be subject to dynamic changes.

However, for measuring instruments in which, as disclosed, for example, in US-A 4768384 or WO-A 0102816, static algorithms that take into account only instantaneous temperature values are used to calculate the corresponding correction coefficients of the measuring signal, this can lead to the fact that, despite the use of such correction coefficients derived, however, from different ones recorded with a local temperature distribution, but always constant in relation to each other, significant inaccuracies can arise and the signal of the measured value in the transient temperature distribution mode, namely for a relatively long period of time. Studies have further shown that such causing, in particular, changes in mechanical stresses inside the sensor, transient transition regions of the temperature distribution can last from several minutes to several hours, and that during this often rather long duration of the transient temperature distribution, the influence of locally recorded temperatures on the measuring signal or measuring signals can also vary with respect to each other.

The possibility of reducing such errors in the measuring signal can consist of such sensors with a vibrating measuring tube, for example, in order to establish a plurality of temperature sensors with a distribution along the measuring tube and along the sensor housing and / or along the supporting element, if necessary, for a single measuring tube sensors.

The disadvantage of such a solution should be seen, in particular, in that, as the number of temperature sensors used increases, the manufacturing costs also increase noticeably. Not to mention the costs of the temperature sensors themselves, the costs of their installation and wiring also increase.

In addition, an increase in the number of temperature sensors can also lead to an increase in the probability of failure of the sensor device itself, in particular when the temperature sensors are fixed on components that vibrate when operating at a high frequency, for example, a measuring tube or a carrier element made in the form of a response vibrator.

The objective of the invention is therefore to improve the measuring instruments for processes of the kind described above in such a way that even in the transient transition region of the temperature distribution inside their respective sensor, the temperature-related errors in the measuring signal are substantially compensated and that, in order to calculate the most accurate correction value for temperature effects on the measuring signal required as few temperature sensors as possible.

To solve this problem, the invention consists in a measuring device for measuring at least one physical parameter of the process, in particular mass flow, density, viscosity, pressure, etc. the medium contained in the tank or flowing through a pipeline including a sensor with a sensing device that supplies measuring signals, which contains at least one first sensor element that primarily responds to the physical parameter of the process, in particular also to changes in the process parameter, and by the first sensor element delivers at least one first measuring signal subject to the physical parameter of the process and, in addition, at least one first located in the sensor a temperature sensor that locally senses the first temperature in the sensor, and which, through at least one temperature sensor, provides at least one first temperature measurement signal representing the first temperature in the sensor, as well as an electronic unit, which, when used, at least the first measuring signal and when using the first correction factor for at least the first measuring signal generates at least one instantly representing the physical the measured parameter, in particular mass flow rate, density, viscosity or pressure, moreover, the electronic unit of the measuring device during operation calculates the first correction coefficient using the time characteristic of at least the first temperature measuring signal due to the fact that the temperature values were also taken into account, previously recorded by the first temperature sensor.

According to a preferred first embodiment of the invention, the electronic unit of the measuring device reacts with a change in the first correction value to a change in the first temperature measurement signal corresponding to a change in the first temperature with a time delay.

According to a preferred second embodiment of the invention, the sensor device comprises at least one located in the sensor, in particular remote from the first temperature sensor, a second temperature sensor that locally senses the second temperature in the sensor, and the sensor device via the second temperature sensor delivers at least one second temperature representing the second temperature measuring signal.

According to a preferred third embodiment of the invention, the meter electronics calculates the first correction value also using the second temperature measurement signal.

According to a preferred fourth embodiment of the invention, the meter electronics calculates a second correction value using the time characteristic of at least the second temperature measurement signal and generates a measured value also using the second correction value.

According to a preferred fifth embodiment of the invention, the electronic unit of the measuring device includes a filter stage for generating at least a first correction value, the first temperature measuring signal being supplied to the first signal input of the filter stage.

According to a preferred sixth embodiment, the filter stage comprises a first analog-to-digital converter for a first temperature measurement signal, converting it into a first digital signal.

According to a preferred seventh embodiment, the filter stage includes a first digital filter for a first digital signal.

According to a preferred eighth embodiment of the invention, the first digital filter is a recursive filter.

According to a preferred ninth embodiment, the first digital filter is a non-recursive filter.

According to a preferred tenth embodiment of the invention, the first digital filter supplies the first correction value to the first signal input of the filter stage.

According to a preferred eleventh embodiment of the invention, the filter stage also serves to generate a second correction value, the second temperature measurement signal being supplied to the second signal input of the filter stage, and it contains a second analog-to-digital converter for the second temperature measurement signal, which converts it into a second digital signal.

According to a preferred twelfth embodiment, the filter stage includes a second digital filter for a second digital signal.

According to a preferred thirteenth embodiment, the sensor includes at least one measuring tube for passing, in particular, a flowing medium.

According to a preferred fourteenth embodiment, at least one of both temperature sensors is located on or near the measuring tube.

According to a preferred fifteenth embodiment of the invention, the sensor includes a housing at least partially covering the measuring tube.

According to a preferred sixteenth embodiment, at least one of the two temperature sensors is fixed to or located at least near the sensor body.

According to a preferred seventeenth embodiment of the invention, the sensor further electrically connected to the electronic unit of the measuring device, mechanically acting on the measuring tube, in particular electrodynamic or electromagnetic, a vibration exciter for driving the measuring tube, and the electronic unit of the measuring device delivers at least one driving signal for controlling the vibration pathogen, so that the measuring tube is at least temporarily in Brier at work.

According to a preferred eighteenth embodiment, the first sensor element responds to vibrations of the measuring tube, in particular from the input or output side, and the measuring signal supplied by the first sensor element represents the mechanical vibrations of the vibrating measuring tube affected by the medium.

According to a preferred nineteenth embodiment of the invention, the sensor includes a carrier element suspended in its housing, in particular with the possibility of oscillation, mounted on the measuring tube to hold the oscillator and at least the first sensor element.

According to a preferred twentieth embodiment of the invention, at least one temperature sensor is fixed to or located at least near the carrier element.

According to a preferred twenty-first embodiment of the invention, the sensor device comprises at least one second sensor element responsive to the physical process parameter and supplies, via the second sensor element, at least one second measurement signal, which is affected by the physical parameter of the process, the electronic unit the measuring device also generates the measured value using the second measuring signal.

The main idea of the invention consists, firstly, in determining the instantaneous sensitivity of the sensor to the measured process parameter, depending on its instantaneous internal temperature distribution and the corresponding compensation of the measurement signals subjected to it. Secondly, the invention concerns the fact that, using previously measured temperatures, it is sufficient to accurately evaluate the instantaneous sensitivity distribution of temperature in the sensor, in particular also using as few temperature sensors as possible.

Another advantage of the invention is, in addition to the small cost of circuitry for measuring temperature, also that more degrees of freedom are created for positioning the temperature sensors inside the sensor, since now the corresponding position of the temperature sensor can also be included in the correction when processing the supplied temperature measurement signal. Thus, temperature sensors can be optimally positioned, in particular also from the point of view of installation and / or wiring technique.

For example, with the vibration-type measuring instruments mentioned above, this also has the advantage that temperature sensors, in order to evaluate the effective temperature distribution in the measuring tube and / or, if necessary, the supporting element, can also be completely fixed on non-vibrating sensor components, for example, the transmitter housing .

Figure 1: in perspective, when viewed from the side, a measuring instrument for processes.

Figure 2: the type of block diagram is intended for the measuring device in figure 1, the electronic unit associated with the sensor of the vibration type.

Figure 3: partially in section, an example embodiment of the sensor intended for the measuring device in figure 1 is a vibration-type sensor in perspective in the first side view.

Figure 4: the sensor of figure 2 in perspective with a second side view.

Figure 5: an example implementation of an electromechanical device for exciting the sensor of figure 2.

6: as a block diagram designed for the electronic unit of the measuring device in figure 2, the processing circuit.

7: a schematic example of possible temperature curves inside the sensor of FIG. 2.

FIG. 8: according to the type of flowchart, the processing circuit of FIG. 6.

Figures 1 and 2 show an example of the implementation of a measuring device, for example, a Coriolis mass flow meter, densitometer and / or measuring device 1 with a vibration sensor 10 preferably placed in the housing 100 and with the housing 200, in which the electronic unit 50 is electrically connected to the sensor 10 .

The measuring device 1 serves to register a process parameter, for example, mass flow rate, density and / or viscosity flowing through a medium pipe and converting a measured value signal instantly representing this process parameter; the pipeline is not shown for clarity.

To pass the medium, the sensor 10 contains a measuring tube 13, which during operation is forced to vibrate mainly in the mode of bending vibrations so that reaction forces, such as Coriolis forces, acceleration forces and / or friction forces, which depend on the process parameter, are created in the flowing medium and have a reverse effect on the sensor 10 with the possibility of measurement, i.e. registration by sensors and electronic processing.

Figures 3 and 4 show an example of a vibration-type physicoelectric conversion device serving as a sensor 10. The design of such a conversion device is described in detail, for example, in US-A 6006609.

To pass the medium to be measured, the sensor 10 includes at least one measuring tube 13 having an input 11 and an output 12 ends with a predetermined, elastically deformable during operation, internal channel 13A and a predetermined conditional passage.

The elastic deformation of the inner channel 13A of the measuring tube means here that in order to create the already mentioned inherent in the medium and, thus, describing the reaction forces medium, the spatial shape and / or spatial position of the internal channel 13A is changed cyclically within the elastic range of the measuring tube 13, in a predetermined manner particularly periodically (US-A 4801897, US-A 5648616, US-A 5796011 or US-A 6006609). If necessary, the measuring tube, as described, for example, in EP-A 1260798, can also be bent. In addition, it is possible, for example, also to use two bent or straight measuring tubes instead of one measuring tube. Other suitable embodiments of such transducer devices serving as sensors 10 are described in detail, for example, in US-A 5301557, US-A 5357811, US-A 5557973, US-A 5602345, US-A 5648616 or US-A 5796011.

As a material for a straight line in FIGS. 3 and 4, the measuring tube 13 is particularly suitable, for example, titanium alloys. Instead of titanium alloys, for example, stainless steel, tantalum or zirconium and the like can also be used for similar, in particular also bent, measuring tubes.

The measuring tube 13, communicating in the usual way on the input and output sides, respectively, with the inlet and outlet of the medium pipe, is clamped with the possibility of oscillation in a rigid, in particular bending and torsionally rigid, covered by the housing 100 of the supporting frame 14.

The carrier frame 14 is fixed to the measuring tube 13 from the input side by means of the input plate 213, and from the output side by the output plate 223, and the respective extensions 131, 132 of the measuring tube 13 pass through both. Further, the carrier frame 14 contains the first 24 and second 34 side plates fixed on the input 213 and output 223 plates so that they extend almost parallel to the measuring tube 13 and are located at a distance from it, as well as from each other (figure 3). Thereby, the side surfaces of both side plates 24, 34 facing each other are also parallel to each other.

On the side plates 24, 34 at a distance from the measuring tube 13, a longitudinal rod 25 is fixed, serving as a damping oscillation of the measuring tube 13 of the balancing mass. The longitudinal rod 25 extends, as shown in FIG. 4, almost parallel to the entire vibrational length of the measuring tube 13; this, however, is not necessary, and if necessary, the longitudinal shaft 25 can be made, of course, also shorter.

The carrier frame 14 with both side plates 24, 34, input 213 and output 223 plates and a longitudinal rod 25 has, therefore, a longitudinal line of gravity, which runs almost parallel to the middle axis 13B of the measuring tube, imaginatively connecting the input 11 and output 12 ends.

In figure 3 and 4, the screw heads indicate that the said fixing of the side plates 24, 34 on the input 213 and output 223 plates and on the longitudinal shaft 25 can be made up; however, other suitable and well-known types of fasteners may be used.

If the sensor 10 needs to be mounted detachably on the pipeline, the first flange 19 is molded on the measuring tube 13 from the input side and the second flange 20 from the output side (Fig. 1); Instead of flanges 19, 20 for detachable connection with the pipeline, other connecting elements can also be molded, for example, the so-called Triclamp connections, indicated in Fig. 3. If necessary, the measuring tube 13 can also be connected directly to the pipeline, for example by welding or high-temperature soldering, etc.

To create the mentioned reaction forces, the measuring tube 13 when the sensor 10 is driven by an electromechanical excitation device 16 connected to the measuring tube is forced to vibrate at a predetermined oscillation frequency, in particular a natural resonant frequency, in the so-called useful mode, as a result of which it is elastically deformed by a predetermined way. As already mentioned, this resonant frequency also depends on the instantaneous density of the medium.

In the illustrated embodiment, the vibrating measuring tube 13, as is customary with such transducer devices of the flexural-vibrational type, spatially, in particular laterally, deviates from the static resting position; the same applies practically to such converting devices in which one or several bent measuring tubes cantilever around the corresponding longitudinal axis connecting imaginatively the corresponding input and output ends, or to such converting devices in which one or more straight measuring tubes make only flat bending vibrations around its longitudinal axis. In another case, when the transducer of the peristaltic radial-vibrational type is used as the sensor 10, as described, for example, in the aforementioned publication WO-A 95/16897, and the cross section of the vibrating measuring tube is symmetrically deformed in the usual way, the longitudinal axis of the measuring tube remains in its static resting position.

Excitation device 16 serves to transform fed to the electronic control unit 50 electric power P excitation _exc create acting on the measuring tube 13 of the excitation force F _exc. The excitation power P _exc serves during excitation with a natural resonant frequency almost only to compensate for the fraction of power taken from the oscillatory system as a result of the mechanical and inherent friction medium. To achieve the highest possible efficiency, the excitation power P _exc is therefore set as accurate as possible with the ability to maintain, basically, the oscillations of the measuring tube 13 in the desired useful mode, for example, with a fundamental resonant frequency.

In order to transfer the excitation force F _exc to the measuring tube 13, the excitation device 16, as shown in FIG. 5, comprises a rigid linkage mechanism 15 driven by an electromagnetic and / or electrodynamic way with a console 154 flexibly rigidly fixed to the measuring tube 13 and a yoke 163. Yoke 163 is also flexurally rigidly fixed on the end of the console 154 that is distant from the measuring tube 13, namely, so that it is located above and across the measuring tube 13.

As the console 154 can serve, for example, a metal washer, which places the measuring tube 13 in the hole. With regard to other suitable arrangements of the linkage 15, reference should here be made to the aforementioned publication US-A 6006609. The linkage 15 is T-shaped and is arranged to act on the measuring tube 13 approximately in the middle between the input 11 and output 12 ends (FIG. 5) As a result, when working, she experiences in the middle her greatest lateral deviation.

To drive the linkage mechanism 15, the excitation device 16 includes, in FIG. 5, a first excitation coil 26 and a corresponding first permanent magnetic armature 27, as well as a second excitation coil 36 and a corresponding second permanent magnetic armature 37. Both preferably connected in series coils 26, 36 excitations are fixed on both sides of the measuring tube 13 under the yoke 163 on the supporting frame 14, in particular detachable, so that they are in operation with their respective armature 27 or 37. In case of need Mosti both coils 26, 36 of excitation may be, by itself, is also connected in parallel.

As shown in FIGS. 3 and 5, both anchors 27, 37 are fixed on the yoke 163 at such a distance from each other that when the sensor 10 is operating, the anchor 27 is penetrated by the almost magnetic field of the excitation coil 26, and the armature 37 is penetrated by the magnetic field of the excitation coil 36 and they move due to the action of the corresponding electrodynamic and / or electromagnetic forces.

The movement of the anchors 27, 37 created by the magnetic fields of the coils 26, 36 are transmitted from the yoke 163 and the console 154 to the measuring tube 13. These movements of the anchors 27, 37 are such that the yoke 163 deviates from its rest position alternately in the direction of the side plate 24, then in the direction of the side plate 34. The corresponding axis of rotation of the linkage 15, parallel to the already mentioned middle axis 13B of the measuring tube, can pass, for example, through the console 154.

The supporting frame 14 serving as a supporting element for the excitation device 16 further includes a connection to the side plates 24, 34, in particular detachably, a holder 29 for holding the excitation coils 26, 36 and, if necessary, the individual components of the magnetic brake device described below 217.

The sensor 10 in this embodiment, the lateral deviations of the vibrating measuring tube 13, firmly clamped at the input 11 and output 12 ends, simultaneously cause elastic deformation of its inner channel 13A, made almost the entire length of the measuring tube 13.

Further, in the measuring tube 13, due to the torque acting on it through the lever mechanism 15, simultaneously with lateral deviations, at least in some sections, twisting occurs around the middle axis 13B, so that the measuring tube 13 oscillates practically in a mixed bending mode serving as a useful mode vibrational-twisting mode. The twisting of the measuring tube 13 can be such that the lateral deviation of the end of the console 154, which is spaced apart from the measuring tube 13, is either equal to or opposite to the lateral deviation of the measuring tube 13. The measuring tube 13 can therefore undergo torsional vibrations in the corresponding case of equal direction of the first - vibrational-torsional mode or, in the corresponding case of anti-directionality, the second flexural-vibrational-torsional mode. Then, the sensor 10 has a natural fundamental resonance frequency of the second flexural-vibrational-torsional mode, for example, 900 Hz, approximately twice as high as in the first flexural-vibrational-torsional mode.

If the measuring tube 13 is to oscillate during operation only in the second bending-vibrational-twisting mode, the magnetic braking device 217 based on the principle of eddy currents is built into the excitation device 16, which serves to stabilize the position of the said axis of rotation. By means of the magnetic braking device 217, it can therefore be ensured that the measuring tube 13 oscillates continuously in the second bending-vibrational-twisting mode and that, thereby, possible external spurious influences on the measuring tube 13 will not lead to a spontaneous transition to another, in particular, not in the first, bending-vibrational-torsional mode. Details of such a magnetic braking device are described in detail in US-A 6006609.

It should also be mentioned here that, in accordance with the second bending-vibrational-twisting mode of the measuring tube 13 deviated, its imaginary middle axis 13B is practically slightly deformed and, thereby, forms not a plane, but rather, weakly convex surface. Further, the path lying on this surface, described by the midpoint of the middle axis of the measuring tube, has a minimum curvature of all the paths described by the middle axis of the measuring tube.

In order to force the measuring tube 13 to vibrate, the excitation device 16 is also supplied with an oscillation excitation current i _exc , in particular of an adjustable amplitude and an adjustable excitation frequency f _exc , with the possibility of it flowing through the excitation coils 26, 36 during operation and generating the necessary for the movement of the anchors 27, 37 magnetic fields. As shown schematically in FIG. 2, the excitation current i _exc is supplied by the operating circuit 50A provided in the electronic unit 50, and it can be, for example, a harmonic alternating current. The excitation frequency f _{exc of the} excitation current i _exc excitation in the embodiment shown here is selected or installed with the possibility of torsional vibration of the laterally oscillating measuring tube 13, if possible, exclusively in the second bending-vibrational-torsional mode.

To detect deformations of the measuring tube 13, the sensor 10 further includes a sensor device 60, which, as shown in FIGS. 2, 3, by means of at least one vibration-sensitive measuring tube 13 of the first sensor element 17 generates a first one representing them, in particular analog, measuring signal s ₁ . The sensor element 17 can be formed, for example, by a permanent magnetic armature, which is fixed on the measuring tube 13 and is in interaction with the sensor coil held by the supporting frame 14.

Particularly suitable as the sensor element 17 are those which, based on the electrodynamic principle, detect the deflection rate of the measuring tube 13. Accelerometer-measuring electrodynamic or path-measuring resistive or optical sensors can also be used. Of course, other sensors known to the person skilled in the art and suitable for detecting such vibrations can be used, for example, recording the stretching of the measuring tube 13.

The sensor device 60 further includes, in particular, a second sensor element 18, identical to the first sensor element 17, by which it also supplies a second measuring signal s ₂ representing the vibrations of the measuring tube 13. Both sensor elements 17, 18 are separated from each other by this embodiment along the measuring tube 13, in particular, are located in the sensor 10 at the same distance from the middle of the measuring tube 13, with the possibility of local registration by means of a sensor device 60 of the vibrations of the measuring tube 13 from the input and output sides and conversion to the corresponding measuring signals s ₁ , s ₂ .

The first s ₁ and, if necessary, the second s ₂ measuring signals, each of which in the usual way corresponds to the instantaneous oscillation frequency of the measuring tube 13, are supplied, as shown in FIG. 2, to the measuring device provided in the electronic unit 50, mainly digital, processing circuit 50B, which is used to calculate, in particular, a numerical instantly representing the recorded process parameter, in particular mass flow, density, viscosity or pressure, the measured value of X and its conversion anija a corresponding, removable from the output signal processing circuit measured value.

According to one preferred embodiment of the invention, the processing circuit 50B is implemented using the microcomputer measuring device provided in the electronic unit 50, which is suitably programmed to calculate the measured value X using the measurement signals provided by the sensor device 60. For the implementation of a microcomputer, for example, both traditional microprocessors and modern signal processors can be used.

While the density or viscosity of the sensor depicted here can be determined using one of the measuring signals s ₁ , s ₂ , if mass flow rate is to be measured, both measuring signals s ₁ , s ₂ are used in a manner known to those skilled in the art. in order, for example, to realistically in the time range of the signal or comprehensively in the frequency range of the signal, calculate the phase difference, which is primarily dependent on the mass flow rate.

The measuring device is also equipped with means that compensate the temperature-related effects on the used measuring signals s ₁ and / or s ₂ and, thus, the high accuracy of the measured value signal also over a wide temperature range also during a change in the temperature distribution inside the sensor.

For this purpose, at least one first temperature sensor 40 is provided in the sensor device 60, which serves to record the first temperature T ₁ at the first measurement location in the sensor and to generate a first electrical, in particular continuous, corresponding to this recorded temperature T ₁ temperature measurement signal θ ₁ . For this, the temperature sensor 40 is arranged in the sensor so that the temperature measurement signal θ ₁ supplied by it, at least with a steady temperature distribution inside the sensor, correlates as well as possible with the temperature of the process medium; it should also be mentioned here that the temperature measuring signal θ ₁ predominantly represents, however, an absolutely measured first temperature, but it can also be, for example, a temperature difference measured relative to a constantly maintained reference temperature.

According to one preferred embodiment of the invention, the temperature sensor 40 is located in the sensor with the ability to measure mainly the temperature of the measuring tube 13 and supplying the first electrical temperature measuring signal θ ₁ corresponding to this measured temperature. The temperature sensor 40 can be placed for this, for example, directly on the measuring tube 13, but then it would be constantly subjected to mechanical vibrations, which, in turn, would bring problems with regard to long-term strength. In the depicted exemplary embodiment, the temperature sensor 40 is therefore located mainly on one of the relatively less strongly oscillating extensions 131, 132 of the measuring tube 13, here from the output side.

According to another preferred embodiment of the invention, to increase the accuracy of the measurement, a second temperature sensor 41 is provided in the sensor device 60, which is located in the sensor 10 with the possibility of detecting a second temperature T ₂ in a second measurement location remote from the first measurement location. For this purpose, the temperature sensor 41, according to one preferred variant of this improvement of the invention, is located on the inner side of the wall of the sensor housing 100, so that it measures practically the temperature of the housing 100 as the second temperature T _2. The temperature sensor 41 can also be fixed, for example, to support frame 14.

Otherwise, it should also be pointed out that with regard to temperature compensation of the measuring signals, it is possible to practically ignore the restrictions on the location of the temperature sensors 40, 41 inside the sensor, which, therefore, gives many other possibilities for positioning at least one temperature sensor 40, as well as other, if necessary, provided temperature sensors. In addition, temperature sensors that can be used are known to those skilled in the art, in particular, temperature sensors and the like, which have been used so far in traditional sensors. Mainly for these applications, in particular, temperature-dependent resistors made of metal, for example Pt100 or Pt1000, or from a semiconductor material, are considered. In addition, if necessary, to compensate for the temperature-related effects of at least one measuring signal, in addition to the temperature sensors 40, 41, other temperature sensors located in the measuring device, for example, also close to the case of the electronic unit, can be taken into account .

As shown in FIGS. 2 or 6, the temperature measurement signals θ ₁ , θ ₂ generated by the temperature sensors 40, 41 and taken at the output of the sensor device 60 are also supplied to the processing circuit 50B and are thus available for further processing, in particular, compensation of the measurement signals s ₁ , s ₂ .

According to one preferred embodiment of the invention, the measuring signal s ₁ , as shown schematically in FIG. 6, is first converted to a temperature-uncompensated or unadjusted intermediate measured value X 'by means of the measuring stage MS provided in the processing circuit 30B. Then, again, by means of a processing circuit 50B using at least one temperature measurement signal θ ₁ supplied by the sensor device 60, they are corrected and converted to the measured value X. However, it is preferable, however, to correct the intermediate measured value X ', at least the temperature sensor θ ₂ supplied by the sensor device 60.

To correct the intermediate measured value X 'inside the corresponding correction stage KS of the processing circuit 50B, at least one first analog or digital correction value K ₁ is determined for the uncorrected intermediate measured value X' derived from at least one measurement signal s ₁ . Further, the thus calculated correction value K ₁ can then be simply multiplied by the uncorrected measured value X 'in the correction stage KS, according to the following simple function:

The correction value K ₁ formed by the correction stage KS is formed, as shown in FIG. 6, taking into account the temperature measuring signal θ ₁ , mainly, however, taking into account at least both temperature measuring signals θ ₁ , θ ₂ supplied by the sensor device.

According to the invention, in addition, at least one used for calculating at least one correction value K _1, the temperature measurement signal θ _{1 is} preliminarily converted into a temperature evaluation signal θ ₁ ^′ . The generation of the temperature evaluation signal θ ₁ ^′ serves to evaluate and transform the instantaneous temperature distribution affected by the temporal characteristics of the first temperature measurement signal θ ₁ as much as possible, namely taking into account not only the instantaneous value of the temperature measurement signal θ ₁ , as suggested in the above-mentioned publications US-A 4768384, US-A 5687100, WO-A 8802476 or WO-A 0102816, but also using the previous signal values. Therefore, using the temperature sensor 40, the temperature values previously recorded by the temperature T ₁ are taken into account. An example of possible characteristics of temperatures T ₁ , T ₂ in the transition region of the time interval t ₂ -t _{1 is} shown schematically in FIG. 7. If necessary, when generating the measured value of X, it is possible, in addition to the temperature evaluation signal θ ₁ ^{′, to} take into account, of course, also the instantaneous value of the temperature measurement signal θ _{1 itself} .

According to one preferred embodiment of the invention, the temperature evaluation signal θ ₁ ^{′ is} generated by the electronic unit 50 of the measuring device based on the following mathematical relation:

Where:

G ₁₀ - variable or maintained constant, in particular, however, a coefficient independent of the measured temperatures;

G ₁₁ is the weighting function of the signal filter, by which the temperature measuring signal θ ₁ supplied by the sensor device is collapsed.

The correction value K ₁ can be calculated using the temperature evaluation signal θ ₁ ^′ by means of simple, in particular linear, mathematical relations, for example, the following:

where k ₁₁ is the first coefficient determining the relationship between the effective temperature measured by the measuring signal θ ₁ and the correction value K ₁ , which is based on the first parameter that is actually taken into account and affects the sensitivity, for example, changing the mechanical stress axially to the measuring tube 13.

If necessary, it is possible, in addition, to calculate the temperature evaluation signal θ ₁ ^′, also take into account, for example, the amplitude-modulated temperature measurement signal θ ₁ in the form of G ₁₂ * θ ₁ ² or the amplitude-modulated temperature measurement signal θ ₂ temperature measuring signal θ ₁ in the form of G ₁₃ * θ ₁ , θ ₂ .

According to one preferred refinement of the invention, for calculating the correction value K ₁ , at least the temperature measuring signal θ _{2 is also} preliminarily converted to the corresponding second temperature evaluation signal θ ₂ ^' , for example, based on the following mathematical relation:

Neglecting possible higher-order terms, it is possible to modify the rule for calculating the correction value K ₁ , which is formulated in equation (3) and depends only on the temperature measuring signal θ _1, as follows:

so that the correction value K ₁ now depends on the temperature measurement signal θ ₁ . The second coefficient k ₁₂ introduced into equation (5), by analogy with equation (3), determines the relationship between the temperature estimated signal θ ₂ ^′ and the correction value K ₁ , which is also based on the first parameter actually taken into account.

Using equation (5), we can then clarify the rule for calculating the measured value of X formulated in equation (1) as follows:

According to one preferred embodiment of the invention, in particular in the case where the instantaneous temperature distribution simultaneously affects several parameters affecting the sensitivity of the sensor, in addition to the correction value K ₁ , a second correction value K ₂ is determined for the unadjusted intermediate measured value X '.

In the sensor depicted here, the instantaneous temperature distribution affects, for example, the elastic modulus of the measuring tube 13 and, although otherwise, the instantaneous distribution of mechanical stresses inside the sensor 10, in particular also inside the measuring tube 13. Accordingly, this instantaneous temperature distribution has also in various ways the effect on its vibrational characteristic, for example, with respect to the natural resonant frequencies of the measuring tube 13 or with respect to the relation between the amplitudes oscillations useful and Coriolis modes.

With this in mind, the calculation of the measured value of X in the correcting cascade occurs mainly on the basis of an expanded mathematical ratio in comparison with equation (1):

The conversion of the measuring signal s ₁ to an intermediate measured value X 'and its combination with a predominantly digital correction value K ₁ or correction values K ₁ , K ₂ has, among other things, the advantage that for this type of calculation of the measured value X using the intermediate measured value the values of X 'and the values of K ₁ , K ₂ corrections do not have to make practically any significant changes in traditional measuring instruments of processes even taking into account others that affect the sensitivity of the parameters. For example, the measured value of X, taking into account the second parameter that affects the sensitivity of the sensor, can simply be calculated as follows:

Where

k ₂₁ is a third coefficient that determines the relationship between the estimated temperature evaluation signal θ ₁ ^′ and the correction value K ₁ , which is based on the second parameter actually taken into account, for example, the changing elastic modulus.

A comparison of the coefficients in equations (6) and (8) shows that the K ₂ correction value can be calculated using the equation:

In order to generate at least one temperature evaluation signal θ ₁ ^{′, the} electronic unit of the measuring device according to the invention includes, according to one preferred embodiment, an upstream filter stage KS for filter temperature stage KS supplied by sensor device 60 for at least with at least one first filter SF ₁ for the temperature measurement signal θ ₁ (Fig.6). In the preferred case, when the correction circuit also uses the second temperature evaluation signal θ ₂ ^′ , at least one second filter SF ₂ for the temperature measurement signal θ _{2 is} further provided in the filter stage FS.

The filters SF ₁ , SF _{2 of the} signals of the filtering stage FS are calculated and coordinated with each other, in particular, they are configured according to their location and parameters with the possibility of as accurate as possible simulation of the measuring signal s ₁ and, if necessary, also the second measuring signal s ₂ the temperature distribution inside the sensor 10 via respectively defined thereby weighting function G _11, G ₂₁ and respectively folded temperature measurement signal θ ₁ or θ _2, namely taking into account not only instantaneous VALUE minutes respectively inputted temperature signal θ ₁ or θ _2, but using the previous temperature θ ₁ signal values or θ _2. In addition, the filters SF ₁ , SF ₂ signals, in particular in relation to the amplification and delay of the signals, are also calculated with the possibility of taking into account the compensating effect of at least an implicitly estimated instantaneous temperature distribution on sensitivity.

Advantageously, the weighting function G _{11 of the} signal filter SF ₁ is selected so that the temperature estimated signal θ ₁ ^′ as a reaction to a change, in particular an increase, of the temperature signal θ ₁ with a noticeable delay takes a value proportional to the instantaneous value of the temperature signal θ ₁ . Accordingly, the electronic unit 50 of the measuring device will then respond to a change in the first temperature measurement signal θ ₁ with a time delay by a change in the first correction value K ₁ . For example, the weight function G ₁₁ may have for this purpose, in addition to the proportionally amplified component, at least one time-integrating component of the first or higher order. Accordingly, the signal filter SF ₁ may be, for example, a low-pass filter.

Filtering devices that are really suitable for the respective type of sensor for the signal filters used can best be preliminarily determined and optimized when developing and designing the measuring device using the prototypes of the measuring device experimentally or using computer numerical calculations, for example, using finite element calculation algorithms. Based on pre-calculated, in particular empirically, filtering devices, it is then possible to determine filter parameters that are really suitable for the corresponding measuring device, for example, using calibration-specific measurements or specific to the type of measuring device, in particular in combination with calculation algorithms that determine numerically filter parameters and optimize them, for example by the least squares method or generisch.

According to one preferred refinement of the invention, the first temperature signal θ ₁ supplied by the sensor device 60 before further processing in the processing circuit, in any case, however, before calculating the correction value K ₁ by the first analog-to-digital converter AD ₁ , as shown schematically in FIG. .7 and 8 are read discretely in time and converted into a first digital signal θ _1D . Similarly, as schematically shown in FIG. 8, the second temperature signal θ ₂ used predominantly in the same way is converted into a second digital signal θ _2D by a second analog-to-digital converter AD ₂ .

In one embodiment of the invention, a digital filter SF _1D serves as a filter for the temperature measurement signal θ ₁ , which converts the following numerical algorithm to calculate the temperature evaluation signal θ ₁ :

moreover, at least two, preferably, however, more possible from M coefficients a _k are non-zero. Similarly, for the temperature measurement signal θ _2, you can use the second digital filter SF _2D (Fig. 8).

If in the general calculation rule given in equation (19), at least one of the possible N coefficients b _k differs from zero, then the digital filter SF _1D implemented in this way is a recursive filter with at least theoretically infinite impulse response; otherwise, the SF _1D digital filter is a non-recursive filter with a finite impulse response.

In the named case, when the temperature measuring signals θ ₁ , θ _{2 are} digitized, i.e. continue to be used in the form of sequences of readings of temperature measuring signals θ ₁ , θ ₂ , the filtering cascade FS using correspondingly powerful microprocessors, in particular signal processors, can be implemented almost completely through the mentioned microcomputer and corresponding software, which also includes calculation algorithms for digital signal filters. Further, it is possible to advantageously achieve the calculation _{of the} correction value K ₁ and the measured value X by executing appropriate computer programs by means of microcomputers.

Knowing the invention, the specialist is unlikely to have difficulties in developing a suitable digital or, if necessary, hybrid, i.e. a mixed analog-digital processing circuitry, in particular also a suitable filter stage, which, on the basis of the available temperature measuring signals θ ₁ , θ ₂ and the corresponding comparative measurements of the process parameter, would process the measuring signal s ₁ or measuring signals so that the uncorrected measured value X 'in combination with at least one correction K ₁ would give a measured value X of sufficient accuracy.

Claims (23)

1. A device for measuring at least one physical parameter, a process, in particular a mass flow rate, density, viscosity, pressure of a medium contained in a tank or flowing through a pipeline, including a sensor (10) of vibration type with measuring signals ( s ₁ , s ₂ ) a sensor device (60), which contains at least one first sensor element (17), which primarily responds to the physical parameter of the process, in particular also to changes in the process parameter, and by means of the first sensor element (17) by flushes at least one first exposed to a physical parameter of the process measurement signal (s _1), wherein the sensor device (60) comprises at least one second, initially responsive to a physical process parameter sensor element (18) and delivers by the second sensor element (18), at least one second measuring signal (s ₂ ) exposed to the physical parameter of the process and, in addition, at least one first temperature sensor (40) located in the sensor (10), are locally recorded the first temperature (T ₁ ) in the sensor (10), and which through at least one temperature sensor (40) provides at least one first temperature measuring signal (θ ₁ ) representing the first temperature (T ₁ ) in the sensor (10), as well as the electronic unit (50), which when using at least the first measuring signal (s ₁ ) and when using the first correction (K ₁ ), at least for the first measuring signal (s ₁ ) produces at least one instantly representing a physical parameter, measured with the beginning (X), in particular mass flow, density, viscosity or pressure, and the electronic unit (50) of the measuring device during operation calculates the first correction value (K ₁ ) using the time characteristic of at least the first temperature measuring signal (θ ₁ ) due to the fact that the temperature values previously recorded by the first temperature sensor (40) were also taken into account. 2. The device according to claim 1, characterized in that the electronic unit reacts to a change in the first temperature measurement signal (θ ₁ ) with a time delay by a change in the first correction value (K ₁ ). 3. The device according to claim 1 or 2, characterized in that the sensor device (60) contains at least one located in the sensor (10), in particular, at a distance from the first temperature sensor (40), the second temperature sensor ( 41), locally detecting the second temperature (T ₂ ) in the sensor (10), and the sensor device (60) through the second temperature sensor (41) provides at least one representing the second temperature (T ₂ ) the second temperature measuring signal ( θ ₂ ). 4. The device according to claim 3, characterized in that the electronic unit (50) calculates the first correction value (K ₁ ) also using the second temperature measuring signal (θ ₂ ). 5. The device according to claim 3 or 4, characterized in that the electronic unit (50) calculates the second correction value (K ₂ ) using the time characteristic of at least the second temperature measuring signal (62) and generates the measured value (X) also using the second correction value (K ₂ ). 6. The device according to one of claims 1 to 4, characterized in that the electronic unit (50) includes a filter stage (FS) for generating at least a first correction value (K ₁ ), the first temperature measuring signal ( θ ₁ ) is supplied to the first signal input of the filtering stage (FS). 7. The device according to claim 6, characterized in that the filtering stage (FS) contains a first analog-to-digital converter (AD ₁ ) of the first temperature measuring signal (θ ₁ ), converting it into a first digital signal (θ _1D ). 8. The device according to claim 7, characterized in that the filtering stage (FS) contains a first digital filter (SF _1D ) for the first digital signal (θ _1D ). 9. The device of claim 8, characterized in that the first digital filter (SF _1D ) is a recursive filter. 10. The device according to claim 8, characterized in that the first digital filter is a non-recursive filter. 11. The device according to claim 5, characterized in that the filtering stage (FS) also serves to generate a second correction value (K ₂ ), the second temperature measuring signal (θ ₂ ) being supplied to the second signal input of the filtering stage (FS), and contains a second analog-to-digital converter (AD ₂ ) of the second temperature measuring signal (θ ₂ ), converting it into a second digital signal (θ _2D ). 12. The device according to claim 7, characterized in that the filtering stage contains a second digital filter for a second digital signal (θ _2D ). 13. The device according to claim 1, characterized in that the sensor includes at least one measuring tube (13) for passing a flowing medium. 14. The device according to item 13, characterized in that at least one of both temperature sensors (40, 41) is located on the measuring tube (13) or near it. 15. The device according to one of claims 13-14, characterized in that the sensor (10) includes a housing (100) covering the measuring tube (13). 16. The device according to clause 15, characterized in that at least one of both temperature sensors (40, 41) is fixed to the sensor housing (100) or located at least near it. 17. The device according to item 13, characterized in that the sensor (10) further includes an electrically connected to the electronic unit (50) of the measuring device, mechanically acting on the measuring tube (13), in particular, an electrodynamic or electromagnetic exciter (16) oscillations for driving the measuring tube (13), and the electronic unit (50) of the measuring device delivers at least one excitation signal (i _exc ) serving to control the exciter (16), causing the measuring tube (13) at least temporarily vibration Rowan at work. 18. The device according to 17, characterized in that the first sensor element (17) responds to the vibration of the measuring tube (13), in particular, from the input or output side, and the measurement signal (si) supplied by the first sensor element (17) represents mechanical vibrations of a vibrating measuring tube (13) exposed to the medium. 19. The device according to claim 17 or 18, characterized in that the sensor (10) includes a carrier element (14) suspended in the measuring tube (13) suspended in its housing (100) to hold the pathogen (16) vibrations and at least a first sensor element (17). 20. The device according to claim 19, characterized in that at least one temperature sensor (40) is fixed on the supporting element (14) or located at least near it. 21. The device according to one of claims _{1 to 4} , characterized in that the electronic unit (50) of the measuring device converts the first temperature measuring signal (θ ₁ ) into a temperature estimation signal (θ ₁ '), which represents the change time signal (θ ₁ ) temperature measurement, instantaneous temperature distribution inside the sensor (10). 22. The device according to one of claims 13 and 14, characterized in that the electronic unit (50) of the measuring device converts the first temperature measuring signal (θ ₁ ) into a temperature estimation signal (θ ₁ ^' ), which represents the change time signal (θ ₁ ) temperature measurement, instantaneous temperature distribution inside the sensor (10). 23. The device according to one of paragraphs.17 and 18, characterized in that the electronic unit (50) of the measuring device converts the first temperature measuring signal (θ ₁ ) into a temperature estimation signal (θ ₁ ^' ), which represents the estimated time signal (θ ₁ ) temperature measurement, instantaneous temperature distribution inside the sensor (10).

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