RU2452935C2 - Measuring system for medium flowing in process pipeline - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: measuring system comprises: at least one temperature sensor, at least one pressure sensor, at least one flow sensor and an electronic measuring unit. The temperature sensor is placed at a temperature measurement point, reacts mainly to local temperature (ϑ) of the flowing medium and transmits at least one temperature measurement signal under the effect of the local temperature of the medium being measured. The pressure sensor is placed at a pressure measurement point, reacts mainly to local, particularly static, pressure (p) of the flowing medium and transmits at least one pressure measurement signal under the effect of the local pressure (p) of the medium being measured. The electronic measuring unit is connected, at least temporarily, to the temperature sensor, pressure sensor and flow sensor. The electronic measuring unit determines a pre-measured density value which is density the flowing medium is only assumed to have at a virtual density measurement point, particularly a density measurement point lying at a predetermined distance along the axis of flow from the pressure measurement point and/or temperature measurement point. The electronic measuring unit, using said pre-measured density value, as well as at least a density correction value determined during operation and depending on the flow rate of the medium as well as local temperature which is predominant at the temperature measurement point, at least temporarily, at least one measured density value, particularly a digital measured density value, different from the pre-measured density value and which, in form of an instantaneous value, is more accurate than the pre-measured density value, the local density (ρ) which the flowing medium actually has at the virtual density measurement point.

EFFECT: high accuracy of measuring pressure or temperature of fluid medium.

44 cl, 4 dwg, 1 tbl

Description

The invention relates to a measuring system for measuring a density of a medium that is variable with respect to a thermodynamic state, in particular at least partially compressible, flowing in a process pipe, such as a process pipe or pipe, along the flow axis in the measurement system. The measuring system takes measurements by means of a temperature sensor, a pressure sensor and a measuring electronic unit, which in each case communicates, at least temporarily, with the temperature sensor and the pressure sensor, and outputs at least temporarily at least one a measured density value representing, as accurately as possible, the local density of this current medium.

To register the measured variables of the current medium describing the technological process, such as the thermodynamic state variable, the density, or the measured variables derived from them, and to output the measured values correspondingly representing such measured variables, measurement systems are used in the measurement technology of the production process that are installed close to this process. This is realized, in particular, also in connection with the automation of chemical processes or processes, including the addition of value to materials. These measurement systems are often composed of two or more separate lower-level measurement devices that communicate with each other, and each of which is located directly on or in the process pipeline through which the medium flows. The measured variables to be recorded may include, in addition to density, also, for example, other variables of the thermodynamic state, in particular those variables that are capable of being recorded by the sensor and, as a result, are directly measured, such as, for example, pressure or temperature, directly or indirectly measured flow parameters, such as, for example, flow rate, volumetric flow rate, such as specific volumetric flow rate, or mass flow rate, such as specific mass flow rate, or other complex transport variables, such as, for example, heat flux, as well as other measured variables related to a particular medium, such as, for example, the viscosity of at least partially liquid, powdery, vaporous or gaseous media transferred to technological pipeline, implemented, for example, in the form of a main pipe.

In particular, for the indirect (referred to below as virtual) density measurement based on pressure and temperature measurement signals generated by appropriate sensors, as well as measured variables, possibly derived from them, for example, mass flow or volume flow, a large number of industrial standards that recommend a largely standardized, and therefore comparable, way of calculating, in particular, also using directly the registrar th e and therefore actually measured temperatures and / or pressures, and which find their application as a function of the application and environment. Examples of such standards include, by way of example, the IAWPS Industrial Formulation 1997 for the Thermodynamic Properties of Water and Steam (IAWPS - IF97) IAWPS Industrial Standard 1997 for the Thermodynamic Properties of Water and Steam (International Association for the Properties of Water and Steam - International Association for the Thermodynamic Properties of Water and Steam), "AGA Manual for the Determination of Supercompressibility Factors for Natural Gas - PAR Research Project NX-19" ("AGA Handbook for determining the compressibility coefficients for natural gas - Scientific American Gas Association Research Project PAR NX - 19 "(AGA - NX19, Library of Congress, 63-23358), International Organization for Standardization ISO 12213: 2006, Section 1-3" Natural gas - Calculation of compression factor "(" Natural gas - calculation of the compression ratio "), as well as the AGA document mentioned there Compressibility Factors for Natural Gas and Other Related Hydrocarbon Gases ", American Gas Association Transmission Measurement Committee Report No. 8 (AGA-8) (American Gas Association: Compressibility Factors for Natural Gas and Other Associated Hydrocarbon Gases", Report No. 8 GAS Transportation and Measurement Committee) and "High Accuracy Compressibility Factor Calculation for Natural Gases and Similar Mixtures by Use of a Truncated Viral Equation", GERG Technical Monograph TM2 1998 & Fortschritt-Berichte VDI (Progress Reports of the Association of German Engineers ), Series 6, No. 231 1989 ("Highly accurate calculation of the compressibility factor for natural gases and similar mixtures st truncated using "viral" equation. "Technical Monograph TM 2, with GERG, the 1998 and Fortschritt-Berichte VDI (Association of Interim reports of German Engineers), Series 6, No. 231 1989) (SGERG-88).

Often, density determination can also serve to convert a directly measured mass flow, ultimately, to an indirectly or virtually measured volume flow or vice versa. For direct measurement of flow parameters, which serve as primary measured variables for this, respectively, for example, local flow rate, local volumetric flow rate or local mass flow rate, the measuring systems of this type include at least one corresponding flow sensor, which, reacting, at least mainly to the flow parameter, which is initially recorded for this current medium, or also to changes in this parameter, it gives at least m D, one measurement signal, in particular an electrical measurement signal, which is under the influence of the respective primary measured variable registered and representing it as accurately as possible. This at least one flow sensor can then be implemented in such a way as to contact the medium at least partially, for example, being immersed in it, or to take measurements externally through the wall of the process pipe or membrane, or aperture. Usually, in this case, the flow sensor is created by, most often, a very sophisticated flow transducer, which is properly installed directly in the process pipe or in the bypass that transfers the medium.

The flow transducers on the market are usually made in the form of pre-calibrated prefabricated modules equipped with a carrier tube that is built into the corresponding process pipeline and also with at least one element that is pre-assembled with it and converts the physical parameter into an electrical signal. This conversion element, possibly in combination with the carrier tube itself and / or other components of the flow transducer, in particular passively-injected components, such as, for example, flow obstructions protruding into the flow, and / or active components of the flow transducer, such as for example, a solenoid device located externally on the support tube to create a magnetic field, or sound-producing elements, forms at least one flow sensor supplying a measuring signal. In industrial measurement technology, in particular, magneto-inductive flow transducers, flow transducers that evaluate the travel time of ultrasonic waves created in the current medium, vortex flow transducers, in particular vortex flow transducers, flow transducers with oscillating measuring tubes, differential flow transducers pressure, or thermal flow meters. The principles of construction and operation of magnetically inductive flow transducers are described, for example, in EP-A 1039269, US-A 6031740, US-A 5540103, US-A 5351554, US-A 4563904, while these principles for ultrasonic flow transducers are presented, for example , in US - In 6397683, US - In 6330831, US - In 6293156, US - In 6189389, US - A 5531124, US - A 5463905, US - A 5131279, US - A 4787252. Since there are also other of the above measurement principles commonly practiced in industrial flow meters is likewise sufficiently well known to those skilled in the art. Anna the art, further explanation of these and other measurement principles adopted in industrial technology and the measurements carried out by measuring the flow transducers may be omitted here.

Industrial measuring systems that record flow parameters often include systems in which at least one of the places of change giving the actual measurement signals and, therefore, hereinafter referred to as real, is formed by a compact measuring device integrated in the pipeline having a transducer flow rate of the above kind. Other examples of such measuring systems, in particular measuring systems, formed by compact, integrated in the pipeline measuring devices with flow converters, known inherently to specialists in this field of technology, in addition, are presented in detail, among other things, in EP - A 605944, EP - A 984248, EP - A 1767908, GB - A 2142725, US - A 4308754, US - A 4420983, US - A 4468971, US - A 4524610, US - A 4716770, US - A 4768384, US - A 5052229, US - A 5052230, US - A 5131279, US - A 5231884, US - A 5359881, US - A 5458005, US - A 5469748, US - A 5687100, US - A 5796011, US - A 5808209, US - A 6003384, US - A 6053054, US - A 6006609, US - B 6352000, US - B 6397683, US - B 6513393, US - B 6644132, US - B 6651513, US - B 6651512, US - B 6880410, US - B 6910387, US - B 6938496, US - B 6988418, US - B 7007556, US - B 7010366, US - A 2002 / 0096208, US-A 2004/0255695, US - A 2005/0092101, US - A 2006/0266127, WO - A 88/02476, WO - A 88/02853, WO - A 95/08758, WO - A 95/16897 , WO - A 97/25595, WO - A 97/46851, WO - A 98/43051, WO - A 00/36379, WO - A 00/14485, WO - A 01/02816, WO - A 02/086426, WO - A 04/023081 or WO - A 04/081500, WO - A 05/095902, as well as in previously unpublished applications DE 102006034296.8 and 102006047815.0 of the copyright holder of this invention.

For further processing or evaluation of the measuring signals issued in the measuring systems, such systems further comprise at least one corresponding measuring electronic unit. A measuring electronic unit, correspondingly communicating with a suitable measuring transducer, in particular also with at least one transducer element, gives out during operation, using at least one measuring signal, at least one periodically measured value, which is an instantaneous representation of the measured variable, respectively, for example, the measured value of the mass flow rate, the measured value of the volumetric flow rate, the measured density value, measured th value of viscosity measured pressure value measured temperature value or the like. Measured values, especially indirectly or also virtually measured density values, are often determined in this case by highly sophisticated calculations in accordance with one of the mentioned industry standards, for example "AGA 4", "AGA 8", "AGA - NX19," IAWPS - IF97 "," SGERG - 88 "or the like.

To accommodate the measuring electronic unit, such measuring systems most often include the corresponding housing of the electronic unit, which, as proposed, for example, in US-A 6397683 or WO-A 00/36379, can be located at a distance from the transmitter and connected to him through a flexible cable. However, as an alternative to this or in addition to this, the housing of the electronic unit can also, as shown, for example, in EP-A 903651 or EP-A 1008836, be located directly on the transmitter or on the housing of the transmitter, separately located in a measuring transducer in such a way as to form a compact measuring device integrated in the pipeline, for example, a Coriolis mass flow / density measuring device, an ultrasonic flow measuring device yes, the vortex flow measurement device, a thermal flow measuring device magnetoinductive flow measuring device or similar device. In the case where the housing of the electronic unit is located on the housing of the transmitter, the housing of the electronic unit, as shown, for example, in EP-A 984248, US-A 4716770, or US-A 6352000, often also serves to accommodate some mechanical components inside it a measuring transducer, such as, for example, elements that are deformed during work on the basis of mechanical stresses, membrane, rod, sleeve or tubular deformable or vibrating elements; in this regard, also compare US - B 6352000, mentioned above.

In the case of measuring systems of the described type, the measuring electronic unit usually has an electrical connection via electric wires or wirelessly by radio to the described electronic data processing system, most often located at a spatial distance and also being spatially distributed with respect to the measuring electronic unit. To this data processing system, the measured values issued by the measuring system are sent as soon as possible. The measured values are sent by means of the measured value signals carrying the measured values. Measuring systems of the described type, in addition, are usually connected via a data transmission network (based on wired and / or radio communication), provided within the framework of the described data processing system, to each other and / or to the corresponding electronic process control units, for example, programmable logic controllers (PLCs) installed locally or process control computers installed in the remote control room where they are being sent I measured values issued by the measuring system and properly represented in digital form, and appropriately encoded. Using computers for process control, the transmitted measured values can be further processed and visualized using appropriate software components as corresponding measurement results, for example, on monitors and / or converted into control signals for other lower-level devices, such as, for example, controlled Magnetically valves, electric motors, etc., implemented as actuators for controlling process. Accordingly, the data processing system also usually serves to convert the signal of the measured value supplied from the measuring electronic unit in accordance with the requirements of the data transmission networks located below (in the data stream), for example, correspondingly representing such a signal in digital form and, if necessary by converting it to the appropriate telegram and / or evaluating it locally. For such purposes, these data processing systems provide for evaluating circuits having electrical connections with corresponding connecting lines that carry out preliminary or subsequent processing, and, if necessary, appropriately convert the measured values received from the measuring electronic unit. For data transmission in such industrial data processing systems, at least in certain areas, in particular, serial, field buses, such as, for example, FOUNDATION FIELDBUS, CAN (controller local area bus), CAN-OPEN (open local bus controller networks), RACKBUS - RS 485, PROFIBUS, etc., or, for example, also networks based on the ETHERNET standard, as well as the corresponding standardized data transfer protocols, which are most often independent of the application.

Usually, using control computers, in addition to such visualization, control and process control, it is also possible to carry out remote maintenance, parameterization and / or monitoring of the connected measuring system. Accordingly, the measuring electronic unit of modern low-level measuring devices allows, in addition to transmitting the actual measured values, also transmit various settings and / or operating parameters used in the measuring system, such as, for example, calibration data, ranges of measured values and / or also diagnostic values defined internally in lower-level devices. In support of this, operational data intended for the measurement system can most often be sent in a similar manner via the aforementioned data networks, which are most often hybrid in terms of data transfer physics and / or data transfer logic.

In addition to the evaluation circuits required for processing and converting the measured values supplied from the connected measuring electronic unit, data processing systems of the described type most often also include power supply circuits used to supply the connected measuring electronic unit, and, as a result, also the corresponding measuring systems of electrical energy or power. Power supply circuits provide the electronic unit of the corresponding measuring device with the proper voltage supply, which, if necessary, is supplied directly via the connected field bus and feeds the power lines connected to the electronic unit of the measuring device, as well as the electric currents flowing in it. The power supply circuit in this case, for example, can be designed entirely for one measuring electronic unit and be placed together with an evaluation circuit associated with a specific measuring device, for example, being connected in such a way as to form an appropriate fieldbus adapter in a housing common to both of them implemented, for example, in the form of a T-profile module. However, it is also not unusual to place such evaluating and power supply circuits in each case in separate buildings, if necessary, at a spatial distance from each other, and properly connect them with wires to each other via external cables.

In the case of industrial measuring systems belonging to the type considered here, often, as a result, we are talking about spatially distributed measuring systems, and in each case, many measured variables of the same and / or different types are locally recorded by sensors in real, separated from other measuring points located along the axis of the flow in the measuring system defined by the process pipeline. These measured variables are supplied to the common measuring electronic unit in the form of corresponding electrical measuring signals via wires, for example, also with the so-called HART®-MULTIDROP method or also with the so-called packet-exclusive mode, and / or wirelessly, in particular by radio, and / or in an optical manner, optionally also encoded in a digital signal or in a digitally transmitted telegram. For the case described above in which such a measuring system is formed by a flow transducer, there is therefore the possibility, for example, in addition to at least one practically directly recorded flow parameter, serving as a primary measured variable, for example, volumetric flow , determine, at least indirectly, and, as a result, measure by means of the same measuring electronic unit, at least virtually, using other remotely recorded measurement variables, for example, remotely detectable local or remote temperature detected local pressure in the environment, and also are output from the secondary measured variables, such as, for example, mass flow rate and / or density.

Experimental studies of distributed measuring systems of the type under consideration, which, as shown, for example, also in US-B 6651512, determine, using directly measured volumetric flow rate and virtually measured density, mass flow rate as an indirectly measured variable, showed that, in particular , also despite the fact that the use of both internally and externally measured variables proved to be very accurate in the measurement ranges common to the corresponding internal On the diameter of the process pipeline, significant errors can occur as a result of a measurement virtual in the above sense. These errors may well lie in the range of, basically, 5% of the actually measured variable, or even beyond. In particular, when defining measurable variables, such as, for example, volumetric flow rate, temperature or pressure, as intermediate variables actually measured, and / or density as an intermediate variable, measured virtually in accordance with the measurement and calculation methods recommended in the aforementioned industrial standards.

In addition, comparative studies in this case additionally showed that the aforementioned measurement errors can demonstrate, among other things, a certain dependence on the instantaneous Reynolds number for the flow, as well as on the instantaneous thermodynamic state of the medium. However, in this regard, it was also found that in numerous industrial applications, especially those related to compressible media and / or at least two-phase media, the Reynolds number or thermodynamic state of the medium can vary greatly not only chronologically, but also and spatially, especially in the direction of the flow axis in the measuring system. In addition to embodiments having at least partially compressible media, in addition, embodiments, in particular, also exhibit significant lateral sensitivity to spatial changes in the Reynolds number or thermodynamic state when the measurement of at least one of measured variables occurs at the measurement location (real or virtual), in which the process pipeline has an inner diameter that varies from at least one of the places of change (real Whether virtual) to another. This, for example, is the case with the use of flow formers that reduce the cross-section of the pipeline (in the same way as it happens in the case of, for example, nozzles serving as so-called pressure reducing elements), which can be used in the inlet region of flow meters, or also when using flow formers that increase the cross-section of the pipeline (the so-called diffusers) in the outlet region of the flow meters. Measuring systems with such reduction elements and / or diffusers are described, for example, in GB - A 2142725, US - A 5808209, US - A 2005/0092101, US - B 6880410, US - B 6644132, US - A 6053054, US - B 6644132, US - A 5052229 or US - B 6513393 and are used, for example, to improve the accuracy of measurement of flow transmitters. In this case, it was also found that such transverse sensitivities caused by the use of pressure reducing elements and / or diffusers are significant for ratios of internal diameters between mainly 0.6 and 0.7, while their influence for ratios of internal diameters with extreme diameter differences of less than 0.2 are very small.

Another area of application with significant sensitivity to the aforementioned changes, as regards their effect on the required measurement accuracy, is also those measuring systems that are designed to measure the flow rate of heavy gases, such as, possibly, carbon dioxide or also phosgene, or long chain carbon compounds having a molecular weight of more than 30 g / mol.

The above-described spatial change in the Reynolds number can, in turn, lead to the fact that practically each of the above-mentioned, real-life places of change in the distributed measuring system, has, during operation, a local value of the Reynolds number, which deviates significantly from the local Reynolds number of each of the other measurement points also used. Similarly, the aforementioned change in the thermodynamic state would also lead to the fact that the measuring points of the distributed measuring system located at a distance from each other may have thermodynamic states that are different from each other. In view of this, therefore, each of the measured variables, which are measured on a distributed basis, would have to be adjusted in accordance with the specific corresponding local value of the Reynolds number and / or the specific corresponding local thermodynamic state, which, in the absence of the information required for this, namely in each case, other but remotely measured state variables are not directly feasible. If, for example, the density and / or mass flow rate, calculated on the basis of the measured state variables - pressure and temperature, were calculated without taking into account the change in the Reynolds number or the thermodynamic state, then the result would be an additional measurement error, which has an essentially quadratic dependence on flow rates. Accordingly, for the aforementioned configuration, at flow velocities less than 10 m / s, the currently required measurement accuracy, generally from 0.1% to 0.5%, is practically no longer significant.

Based on the above-described disadvantages of measuring systems of the described type, especially those that determine mass flow rate or volumetric flow rate, the objective of the present invention is to increase the measurement accuracy for such secondary measured variables, determined using spatially distributed variables of a thermodynamic state, such as pressure and / or temperature.

To solve this problem, a measuring system has been created for measuring the density of the medium, which is variable in part of the thermodynamic state, in particular, at least partially compressible, flowing in the process pipeline along the flow axis in the measuring system. To this end, the measuring system comprises at least one temperature sensor located at the temperature measurement site, responding mainly to the local temperature (ϑ) of the flowing medium and supplying at least one temperature measurement signal influenced by the local temperature medium to be measured; at least one pressure sensor located in the place of pressure measurement, reacting mainly to local pressure (p), in particular the static pressure of the flowing medium and supplying at least one pressure measurement signal under the influence of local pressure (p) in the medium to be measured; and a measuring electronic unit, in each case communicating, at least temporarily, at least with a temperature sensor and a pressure sensor, wherein the measuring electronic unit, using both signals: a temperature measurement signal and also at least a measurement signal pressure, determines, in particular, in accordance with one of the industry standards AGA 8, AGA NX - 19, SGERG - 88 IAWPS - IF97, ISO 12213: 2006, a preliminary measured density value representing the density that the current medium only supposedly has in the usual place of density measurement, in particular in the virtual place of density measurement, located at a predetermined distance along the flow axis, from the place of pressure measurement and / or the place of temperature measurement, and the measuring electronic unit, using this preliminary measured density value, is equal to and applying at least one density correction value, determined during operation and depending both on the flow rate of the medium and also on the local temperature prevailing in the place of temperature measurement tours, gives at least temporarily at least one measured density value, in particular a digital measured density value, different from the preliminary measured density value and representing, as an instantaneous value, more accurately than the preliminary measured density value, local density ( ρ), which the current medium actually has in the virtual place of density measurement.

In the first embodiment of the invention, it is provided that the density correction value corresponds to the instantaneous local variability of at least one variable of the thermodynamic state of the medium, in particular, while such instantaneous local variability refers to the medium to be measured at the current time, as well as to the instantaneous circumstances of the installation, and / or despite the fact that such instantaneous local variability takes place along the axis of the flow in the measuring system, and / or the correction value local density corresponds to the instantaneous variability of the Reynolds number of the flowing medium, in particular, given that the local variability of the Reynolds number relates to the environment and / or type-measuring system, or, moreover, that the instantaneous variability of the Reynolds number occurs along the axis of flow in the measuring system.

In a second preferred embodiment of the invention, it is provided that the measuring electronic unit determines periodically during operation a density error corresponding to a deviation, in particular a relative deviation, of the preliminary measured density value from the measured density value, and, in particular, also gives such an error in the form of a numerical measured density values. It is further provided that the measuring electronic unit provides an instantaneous density error in the form of a numerical value of the density error and / or compares the instantaneous density error with at least one predetermined reference value and, based on this comparison, temporarily generates an alarm signaling about an undesirable, in particular, unacceptably high discrepancy between the preliminary measured density value and the measured density value.

In a third preferred embodiment of the invention, it is provided that the measuring electronic unit determines the measured density value using both values from among the preliminary measured density value and also the density correction value.

In a fourth preferred embodiment of the invention, it is provided that the measuring electronic unit determines the measured density value using both values from among the preliminary measured density value and also the density correction value, and that the measuring electronic unit applies the density correction value when generating the measured density value only when it is at least one and, in particular, lies in the range from 1 to 1.2.

In a fifth preferred embodiment of the invention, it is provided that the measuring electronic unit determines the measured density value using both values from the preliminary measured density value and also the density correction value, and that the measuring electronic unit applies the density correction value when generating the measured density value only when it is the largest unit, and, in particular, lies in the range from 0.8 to 1.

In a sixth preferred embodiment of the invention, it is provided that the measuring electronic unit periodically compares the density correction value with at least one predetermined reference value during operation. It is additionally provided that the measuring electronic unit, based on a comparison of the density correction value and the reference value, quantitatively signals the instant deviation of the density correction value from the reference value and / or generates, temporarily, an alarm signaling an undesirable, in particular, unacceptably high discrepancy between density correction value and corresponding reference value.

In a seventh preferred embodiment of the invention, it is provided that the measuring electronic unit comprises a data memory, in particular a non-volatile data memory, which stores at least temporarily at least one parameter of the measuring system, which determines exclusively the medium to be measured at a given moment in time, in particular, such a system parameter as the specific heat (c _p ) of the medium to be measured at the current time, the molar mass (n) of the medium and / or the number (f) of vibrational degrees freedom of atoms or molecules of the medium, which is determined by the molecular structure of the medium.

In an eighth preferred embodiment of the invention, it is provided that the measuring electronic unit determines the measured density value using at least one parameter of the measuring system that determines exclusively the medium to be measured at the current time.

In a ninth preferred embodiment of the invention, it is provided that the measuring electronic unit comprises a data memory, in particular a non-volatile data memory, which stores at least temporarily at least one parameter of the measuring system, which defines both the medium to be measured by the measuring system, and and instant circumstances of the installation of the measuring system, while the circumstances of the installation are determined by the location (relative to each other) of the places of pressure change, t temperature and density, as well as, in each case, the shape and size of the process pipeline in the areas of pressure, temperature and density. The measuring electronic unit also determines the measured density value using this at least one parameter of the measuring system, which determines both the medium to be measured at the current time by the measuring system and also the instant circumstances of the installation of the measuring system.

In a tenth preferred embodiment of the invention, it is provided that the measuring electronic unit comprises a data memory, in particular a non-volatile data memory, which stores at least temporarily at least one parameter of the measuring system related to the first view, defining the medium to be measured in the current time, in particular, the specific heat of the medium to be measured at the current time, the molar mass of the medium and / or the number of degrees of freedom of the medium, and which stores, by m at least temporarily, at least one parameter of the measuring system related to the second type, which determines both the medium to be measured at the current moment of time and also the instantaneous circumstances of the installation of the measuring system, while the circumstances of the installation are set by the location (relative to each other ) places of change in pressure, temperature and density, as well as, in each case, the shape and size of the process pipe in the areas of places of pressure, temperature and density, and electrons unit determines the measured density using the at least a parameter measurement system pertaining to the first type and a parameter of the measuring system referring to the second form.

In an eleventh preferred embodiment of the invention, it is provided that the measuring electronic unit receives, at least temporarily, the numerical values of the parameter, in particular the numerical values of the parameter determined in a manner external to the measuring system and / or recently in time, for at least one parameter of the measuring system that determines the medium to be measured, and / or the instant circumstances of the installation of the measuring system, in particular, the heat capacity (c _p ) for the medium to be measurement, which represents the specific heat (c _p ), previously determined and / or measured at a distance from the density measurement site for the medium to be measured.

In a twelfth preferred embodiment of the invention, it is provided that the measuring electronic unit communicates, in particular via a field bus, at least temporarily, in particular via wires and / or radio, with a superior electronic data processing system. Additionally, it is provided that the measuring electronic unit transmits the measured density value to the data processing system, and / or the measuring electronic unit receives, from the data processing system, at least temporarily, the parameters of the measuring system that determine the numerical values of the parameters for the medium to be measured at the moment time, in particular, its thermodynamic properties and / or its chemical composition, in particular, the specific heat (c _p ) of the medium to be measured at the current time nor the molar mass (n) of the medium to be measured at the current time, and / or the number (f) of degrees of vibrational freedom of atoms or molecules of the medium to be measured at the current time, and / or that the measuring electronic unit is connected to an electronic processing system data via a fieldbus, in particular a serial fieldbus.

In a thirteenth preferred embodiment of the invention, it is provided that the measuring electronic unit determines, during operation, at least temporarily, the specific heat (c _p ) of the medium to be measured at the current time, in particular, based on the formula:

,

,

in which n represents the molar mass, R is the absolute gas constant, with R = 8.3143 J / (K · mol) and f is the number (determined by the molecular structure of the medium) of the degrees of vibrational freedom of its atoms or molecules.

In a fourteenth preferred embodiment of the invention, it is provided that the measuring electronic unit periodically generates a measured temperature value, in particular a digital measured temperature value, based on a temperature measurement signal, and wherein the measured temperature value represents, as an instantaneous value, the temperature of the medium at the temperature measurement site .

In a fifteenth preferred embodiment of the invention, it is provided that the measuring electronic unit periodically generates a measured pressure value, in particular a digital measured pressure value, based on the pressure measurement signal, and the measured pressure value represents, as an instantaneous value, the pressure of the medium prevailing in the medium in particular at the place of pressure measurement.

In a sixteenth preferred embodiment of the invention, it is provided that the measuring system further comprises a flow sensor located at the place of flow measurement and reacting mainly to a local flow parameter, in particular a flow parameter averaged over the cross section of the process pipe, in particular, the flow rate, volumetric flow rate or mass flow rate, of the medium to be measured, in particular also on their changes, and the flow sensor provides at least one measurement signal flow rate grains influenced by this local flow parameter.

In addition, it is provided that the measuring electronic unit communicates, at least temporarily, also with the flow sensor, and the measuring electronic unit determines the measured density value, using also a flow measurement signal; and / or

the medium has a thermodynamic state in the virtual place of density measurement corresponding to the thermodynamic state of the medium at the place of velocity measurement; and / or

the virtual location of the density measurement and the location of the flow measurement, at least partially overlap each other, in particular, they are the same; and / or

the temperature measurement location and the flow measurement location overlap at least partially, in particular, they coincide; and / or

the pressure measurement location and the flow measurement location overlap at least partially; and / or

the measured density value represents the local density of the medium in the area of the flow sensor; and / or

the measuring electronic unit communicates with the flow sensor via a field bus, in particular a serial field bus, and / or wirelessly via radio; and / or

the measuring electronic unit communicates, at least temporarily, with the flow sensor, while the measuring electronic unit determines, using at least a flow measurement signal, a measured speed value, in particular a digital measured flow value, which represents the speed as an instantaneous value flow of the current environment.

In a seventeenth preferred embodiment of the invention, it is provided that the measuring electronic unit also provides a measured density value using at least one numerical correction coefficient, in particular a correction coefficient stored in digital form, which corresponds to local variability taking place along the flow axis in measuring system, in particular, local variability (determined in advance or during operation) of at least one thermodynamic variable th state of the environment, particularly temperature, pressure or density, and / or corresponds to the local variation taking place along the axis of flow in the measuring system, in particular local variability (defined in advance or during operation) the Reynolds number of the flowing medium.

It is further provided that at least one correction factor is determined taking into account the medium actually being measured, in particular its composition and / or its thermodynamic properties, in particular during calibration of the measuring system using a known reference medium and / or during start-up of the measuring system at the place of its operation; and / or

the measuring electronic unit determines the correction factor at least once during the start-up of the measuring system; and / or

the measuring electronic unit determines the correction factor periodically during operation of the measuring system, in particular, in connection with a change in at least one chemical property of the medium to be measured, or in connection with the replacement of this medium by another medium; and / or

the measuring electronic unit determines this at least one correction coefficient based on a predetermined specific heat capacity (c _p ) of the medium currently available, in particular heat capacity, determined in dialogue with the user and / or external to the measuring electronic block way; and / or

the measuring electronic unit comprises a data memory storing this at least one correction factor, in particular a data memory implemented as a table memory and / or non-volatile memory; and / or

a data memory stores a plurality of correction factors determined in advance for various environments and / or for various installation circumstances; and / or

the measuring electronic unit selects this at least one correction factor, taking into account the environment available at the current time, as well as the installation circumstances available at the current time, from the set of correction factors stored in the data memory.

In the eighteenth preferred embodiment of the invention provides that the measuring electronic unit, based on the pressure measurement signal, as well as on the temperature measurement signal, determines the preliminary measured density value, in particular, in accordance with one of the industry standards AGA 8, AGA NX - 19, SGERG - 88 IAWPS - IF97, ISO 12213: 2006, representing the density that the current medium only supposedly has in a virtual density measurement location.

It is additionally provided that the measuring electronic unit periodically determines during operation a density error corresponding to a deviation, in particular the relative deviation of the preliminary measured density value from the measured density value, and, in particular, also gives such an error in the form of a numerical, measured density value; and / or

the measuring electronic unit provides an instantaneous density error corresponding to a deviation, in particular a relative deviation of the preliminary measured density value from the measured density value, in the form of a numerical value of the density error and / or compares the instantaneous density error with at least one predetermined reference value and, Based on this comparison, it generates, temporarily, an alarm signaling an undesirable, in particular, unacceptably high discrepancy m I am waiting for the preliminary measurement density value and the measured value of density.

In a nineteenth preferred embodiment of the invention, it is provided that the measuring system further comprises at least one flow sensor located at the place of flow measurement and reacting mainly to a local flow parameter, in particular a flow parameter averaged over the cross section of the process pipe in particular, the flow rate, volumetric flow rate or mass flow rate of the medium to be measured, in particular, also on changes in this parameter, and the supply, at least dynes flow measurement signal being influenced by the local flow parameter, wherein

the measuring electronic unit communicates, at least temporarily, with the flow sensor, and the measuring electronic unit, using at least a flow measurement signal, determines the measured value of the volumetric flow rate, in particular the digital measured value of the volumetric flow rate, representing, in the form instantaneous value, specific volumetric flow rate of the current medium; and / or

the measuring electronic unit determines, using at least the measured density value and the measured value of the volumetric flow rate, the measured mass flow rate value, in particular the digital measured mass flow rate value, representing, in the form of an instantaneous value, the specific mass flow rate of the current medium; and / or

wherein the measuring electronic unit determines, using at least the temperature measurement signal, the pressure measurement signal and the flow measurement signal, the measured mass flow rate, in particular the digital measured mass flow value, representing, in the form of an instantaneous value, the specific mass flow rate of the current environment; and / or

the flow measurement site is located upstream of the temperature measurement site and / or upstream of the pressure measurement site; and / or

this at least one flow sensor is formed by at least one piezoelectric element and / or by at least one piezoresistive element; and / or

this at least one flow sensor is formed by at least one element - electrical resistance, in particular, an element - resistance, through which at least temporarily flows a heating electric current; and / or

this at least one flow sensor is formed by at least one measuring electrode measuring electric potentials, in particular a measuring electrode in contact with the current medium; and / or

this at least one flow sensor is formed by at least one measuring capacitor responsive to changes in the flow parameter; and / or

this at least one flow sensor, especially a flow sensor protruding at least partially into the lumen of the process pipe, is located downstream of at least one body of a streamlined shape immersed in the medium and protruding into the lumen of the process pipe .

In a twentieth preferred embodiment of the invention, it is provided that the measuring electronic unit communicates with the temperature sensor via a field bus, in particular a serial field bus, and / or wirelessly by radio.

In a twenty-first preferred embodiment of the invention, it is provided that the measuring electronic unit communicates with the pressure sensor via a fieldbus, in particular a serial fieldbus, and / or wirelessly by radio.

In a twenty-second preferred embodiment of the invention, it is provided that the medium at the site of the density measurement is in a thermodynamic state that differs, at least temporarily, to a large extent, in particular to a degree significant for the required accuracy for the accuracy of the measurement of the measuring system, in that relates to at least one local variable of the thermodynamic state, in particular temperature and / or pressure and / or density, from the thermodynamic state of the medium in the place of measurement temperature and / or thermodynamic state of the medium at the place of pressure measurement.

In a twenty-third preferred embodiment of the invention, it is provided that the current medium has a Reynolds number greater than 1000.

In a twenty-fourth preferred embodiment of the invention, it is provided that the medium is compressible, having, in particular, compressibility K = −1 / V × dV / dp, which is greater than 10 ⁻⁶ bar ⁻¹ (10 ⁻¹¹ Pa ⁻¹ ), and / or is at least partially gaseous. The medium, in this case, may be a gas filled with solid particles and / or liquid droplets.

In a twenty-fifth preferred embodiment of the invention, it is provided that the medium has two or more phases. One phase of the medium may then be a liquid, and / or the medium may be a liquid containing gas and / or solid particles.

In a twenty-sixth preferred embodiment of the invention, it is provided that the measuring system further comprises a display element that supports, at least temporarily, communication with the measuring electronic unit, for visually indicating at least the measured density value.

In a twenty-seventh preferred embodiment of the invention, it is provided that the process pipeline is implemented in at least some of its sections, especially in the region of at least the density measurement point and / or in the region of at least the pressure measurement point, such as a pipeline, essentially stable in shape, at least under the action of operating pressure, in particular in the form of a rigid pipe and / or pipe having a circular cross section.

In a twenty-eighth preferred embodiment of the invention, it is provided that the process pipe is implemented in at least some of its sections, especially in the area between the place of density measurement and the place of pressure measurement and / or between the place of density measurement and the place of temperature measurement, as essentially , a straight pipe, in particular a pipe having a circular cross section.

In a twenty-ninth preferred embodiment of the invention, it is provided that the process pipe has an inner diameter at the virtual density measurement site that is different from the internal diameter of the process pipe at the pressure measurement site. It is preferable that the inner diameter of the process pipe is larger at the pressure measurement site than the inner diameter of the process pipe at the virtual density measurement site, in particular, it is provided that the ratio of the inner diameters: the inner diameter of the process pipe at the pressure measurement site to the inner diameter of the process pipe at the virtual measurement site density, maintained greater than 1.1.

In a thirtieth preferred embodiment of the invention, it is provided that the ratio of the inner diameters: the inner diameter of the process pipe at the pressure measurement site to the inner diameter of the process pipe at the virtual density measurement site is maintained less than 5.

In the thirty-first preferred embodiment of the invention, it is provided that the ratio of the inner diameters: the inner diameter of the process pipe at the pressure measurement site to the inner diameter of the process pipe at the virtual density measurement site is maintained in the range from 1.2 to 3.1.

In a thirty-second preferred embodiment of the invention, it is provided that the process pipeline has a straight section between the virtual density measurement site and the pressure measurement site, which is implemented as a diffuser, in particular a funnel-shaped diffuser having a lumen widening in the direction of flow, in particular continuously expanding.

In a thirty-third preferred embodiment of the invention, it is provided that the process pipeline has a straight section between the virtual density measurement site and the pressure measurement site, which is implemented as a nozzle, in particular a funnel-shaped nozzle having a lumen tapering in the direction of flow, in particular tapering continuously.

In a thirty-fourth preferred embodiment of the invention, it is provided that the process pipe has an inner diameter at the virtual density measurement site that is substantially equal to the internal diameter of the process pipe at the pressure measurement site.

In a thirty-fifth preferred embodiment of the invention, it is provided that the process pipe has an inner diameter at the virtual density measurement site that is different from the inside diameter of the process pipe at the temperature measurement site. It is preferable that the inside diameter of the process pipe is larger at the temperature measurement site than the inside diameter at the virtual density measurement site, in particular that the ratio of the inside diameters: the inside diameter of the process pipe at the temperature measurement site to the inside diameter of the process pipe at the virtual density measurement site is supported by greater than 1.1.

In a thirty-sixth preferred embodiment of the invention, it is provided that the ratio of the inner diameters: the inner diameter of the process pipe at the temperature measurement site to the inner diameter of the process pipe at the virtual density measurement site is maintained less than 5.

In a thirty-seventh preferred embodiment of the invention, it is provided that the ratio of the inner diameters: the inner diameter of the process pipe at the temperature measurement site to the inner diameter of the process pipe at the virtual density measurement site is maintained in the range from 1.2 to 3.1.

In a thirty-eighth preferred embodiment of the invention, it is provided that the process pipe has a straight section between the virtual density measuring point and the temperature measuring point, implemented as a diffuser, in particular a funnel-shaped diffuser having a lumen widening in the direction of flow, in particular continuously expanding.

In a thirty-ninth preferred embodiment of the invention, it is provided that the process pipe has a straight section made between a virtual density measuring point and a temperature measuring place in the form of a nozzle, in particular a funnel-shaped nozzle having a lumen becoming narrower in the flow direction, in particular continuously narrower .

In a fortieth preferred embodiment of the invention, it is provided that the process pipe has an internal diameter substantially equal to the internal diameter of the process pipe at the temperature measurement site at the virtual density measurement site.

In a forty-first preferred embodiment, the virtual density measurement site is located upstream of the temperature measurement site and / or upstream of the pressure measurement site.

In a forty-second preferred embodiment of the invention, it is provided that the pressure measuring point is located downstream of the temperature measuring point.

In a forty-third preferred embodiment of the invention, it is provided that the distance by which the pressure measurement location is away from the virtual density measurement site is different from the distance by which the temperature measurement location is away from the virtual density measurement site.

In a forty-fourth preferred embodiment of the invention, it is provided that the distance by which the pressure measurement location is away from the virtual density measurement site is greater than the distance by which the temperature measurement location is away from the virtual density measurement site.

In a forty-fifth preferred embodiment of the invention, it is provided that the distance by which the pressure measurement location is away from the virtual density measurement site is greater than the internal diameter of the process pipe at the pressure measurement location, and / or wherein the distance by which the pressure measurement location is away from the place temperature measurements larger than the inside diameter of the process pipe at the pressure measurement site. Further, the distance by which the pressure measurement place is located away from the virtual density measurement place corresponds to at least three times, in particular more than five times the internal diameter of the process pipe at the pressure measurement place, and / or the distance by which the pressure measurement place spaced from the place of temperature measurement, corresponds to at least three times, in particular, more than five times the inner diameter of the process pipe at the point of pressure measurement.

In a forty-sixth preferred embodiment of the invention, it is provided that the measuring electronic unit comprises a microcomputer. It is further envisaged that the measuring electronic unit provides at least a measured density value by means of a microcomputer.

In a forty-seventh preferred embodiment of the invention, it is provided that the measuring system further comprises at least one housing of the electronic unit, in particular a housing that is resistant to explosions and / or pressure and / or shock and / or weathering, in which, at least partially, the measuring electronic unit is located. It is further envisaged that this at least one, in particular metal, housing of the electronic unit is attached to the process pipe and / or located in the immediate vicinity of the virtual density measurement site.

The main idea of the invention is to improve the measurement accuracy of measuring systems of the described type, determining with improved accuracy the density derived from actually real, but, however, necessarily measured in a distributed manner, state variables. This output density serves as a central measured variable in numerous applications of industrial measurement technology in the case of current media. Improved accuracy is achieved by taking into account the possible spatial change (in particular, also the degree of this change) of the Reynolds number and / or thermodynamic state of the current medium. In the case of a measuring system according to the invention, this is achieved by reliably calculating the density, by correlating it with some reference location, previously determined for a particular measuring system and serving as a fixed measurement location. Density is thus measured virtually. The measurement accuracy with which the measuring system determines the local density can be further significantly improved by the fact that the measurement system determines the mentioned density also takes into account the locally measured, existing flow velocity, in order to further compensate for the error accompanying the mentioned changes in the Reynolds number and / or thermodynamic state of the current environment.

The invention is based on the unexpected fact that a spatial change in the Reynolds number and / or thermodynamic state, and the associated measurement errors, can be projected onto a single coordinate lying in the direction of flow and / or coinciding with the axis of the stream in the measuring system and thus can be transformed into an appropriately simplified set of parameters of the measuring system, which can be determined, at least advantageously, in advance, experimentally and / or using a computer, for example, during calibration of a measuring system, at the time of completion of its manufacture and / or during its start-up. Spatial changes or their degree and, as a result, also a set of device parameters are truly individual for each specific measuring system and each specific medium, so that the calibration is individual, but such a calibration can in this case, however, be considered invariant with respect to possible changes in the Reynolds number and / or thermodynamic state that occur during operation, if the measuring system remains unchanged with the medium essentially constant, as for its chemical composition. For a given distributed measuring system, the magnitude of the changes in the thermodynamic state occurring along the flow axis can be determined in advance so that their influence can be calibrated and, as a result, also compensated with an accuracy sufficient for measurements, and it was surprisingly found that the change is largely constant for a given measuring system with a constant medium, so that such a change can be transformed into a set of truly individual, but also permanent device parameters.

An advantage of the invention is that this fundamental method can be adapted to numerous already installed measuring systems, at least to the extent that the electronic unit of the measuring device allows for the modification of the corresponding data processing software.

The invention, as well as additional preferred embodiments thereof, will now be explained below based on preferred embodiments of the invention, if necessary with reference to the drawings, in which the following is presented:

figure 1 is a perspective view from the side of the measuring system for measuring local density, which has a medium flowing in the process pipe at the place of measurement of density, by means of a pressure sensor located at the place of pressure measurement, and a temperature sensor located at the place of temperature measurement;

figure 2 - the measuring system shown in figure 1, this time in the form of a structural diagram;

figa, 3b are perspective views and partially cut, at different angles, of a vortex flow transducer suitable for use in the measuring system shown in figure 1, and operating in accordance with the vortex principle; and

Figa-4h, 5 is a sectional view of various embodiments of the process pipeline and for the relative location of individual places of change in the measuring system shown in Fig.1.

Figure 1 shows in schematic form a measuring system (1), which can be built on a modular basis and which is designed to determine, at least temporarily, and very accurately and, equally, very reliably the density of the medium flowing in technological pipeline (20) and in order to convert such a density, sometimes even in real time, into a corresponding reliable, for example, even a digital, measured value (X _ρ ) of density. In addition to a single-phase medium, it is also possible that the medium may have two or more phases. Examples of media include, for example, gas, liquid (which may contain gas and / or solid particles), gas containing solid particles and / or droplets of liquid, steam or water vapor (which may be saturated steam or dry steam) or the like, such as hydrogen, nitrogen, chlorine, oxygen, helium or the compounds and / or mixtures formed therefrom, such as, for example, carbon dioxide, water, phosgene, air, natural gas or other hydrocarbon mixtures.

In particular, the measuring system is designed for very accurate measurement of the density of the current medium, also for the case in which the medium is variable in terms of the thermodynamic state along the flow axis in the measuring system, which, for example, can occur in situations where which inside the technological pipeline there is a chemical reaction of the medium, either for piecewise cooled media or for piecewise heated media, compressible media and / or in the case of technological pipelines, cross section ryh changes in the flow direction axis. This measuring system, in addition, is designed to determine the density of current media having a Reynolds number (Re) greater than 1000, and / or compressible media having a compressibility (K) of more than 10 ^-6 bar ^-1 (10 ^{- 11} Pa ^-1 ).

For this, the measuring system contains at least one temperature sensor located in the place (M _ϑ ) of the temperature measurement, reacting mainly to the local temperature (ϑ) and giving at least one signal (x _□ ) of the temperature measurement under the influence of such a local temperature of the flowing medium to be measured; as well as at least one pressure sensor located in the place (M _p ) of the pressure measurement, reacting mainly to local, for example, static and / or absolute pressure (p) of the flowing medium to be measured, and supplying at least one pressure measurement signal (x _p ) influenced by such local pressure in this medium. Although the pressure measurement location in the example of the embodiment of the invention shown here is located downstream of the temperature measurement location, of course, if necessary, it can also be located upstream of the temperature measurement location.

In addition to the temperature sensor and the pressure sensor, the measuring system further comprises at least one measuring electronic unit 100, supporting at least temporarily communication with both the temperature sensor and the pressure sensor and receiving, by wire and / or wirelessly, measuring signals (x _ϑ ), (x _p ) from the temperature sensor and pressure sensor. The measuring signals (x _ϑ ), (x _p ), if necessary, can be properly converted before being sent to the measuring electronic unit 100.

The temperature sensor can, for example, be an industrial temperature sensor, such as, for example, a thermocouple or resistance thermometer of the Pt 100 or Pt 1000 type, while the pressure sensor can, for example, be an industrial pressure sensor, particular absolute and / or relative, for example a sensor with a capacitive element for measuring pressure. Of course, if necessary, other pressure measuring elements can also be used that convert pressure values recorded and transmitted from the medium into the corresponding measuring signals, as well as other suitable temperature sensors. In addition, the temperature sensor can be provided, for example, as a component of an independent temperature measuring device, industrial type, having its own electronic unit of the measuring device. Such temperature measuring devices, which are inherently known to those skilled in the art, are widely recognized in process measurement technology and are sold, for example, also by Endress + Hauser Wetzer GmbH + Co. KG, under the designations "Easytemp TSM" or "Omnigrad T ". As an alternative to this or in addition to this, the temperature sensor can, as explained in more detail below, also be implemented as an integral part of a complex measuring device integrated into the pipeline, possibly even registering a plurality of measured variables of the current medium. The pressure sensor can also be an integral part of such a complex integrated in the pipeline measuring device or component of an independent pressure measuring device, industrial type, with its own electronic unit of the measuring device. Such pressure measuring devices, similarly known to those skilled in the art, are also widely recognized in the process measurement technology and are sold, for example, also by the company "Endress + Hauser Wetzer GmbH + Co. KG", under the designations "Cerabar S", "Cerabar M "or" Cerabar T ". However, in addition, the pressure sensor and the temperature sensor can also be provided in the form of a single measuring device for measuring pressure and temperature, for example, in the form of an industrial combined measuring device, which is proposed in WO-A 97/48970.

As schematically shown in FIG. 1, the measuring electronic unit can be placed, at least partially, in the housing 110 of the electronic unit, in particular the housing, which is resistant to explosions and / or pressure and / or shock and / or atmospheric impacts. The housing 110 of the electronic unit, made, for example, of metal, can, as also shown in figure 1, if necessary, be installed on the process pipeline.

For further processing of the pressure measurement signal and the temperature measurement signal carried out inside the measuring system, one embodiment of the invention additionally provides a microcomputer (μC) in the measuring electronic unit, which also serves, in particular, to provide a measured density value (X _ρ ) and which can be formed for example, by means of at least one microprocessor and / or by means of at least one signal processing processor. As an alternative to this or in addition to this, specialized application integrated circuits (ASICs) and / or programmable logic components or systems, such as, for example, so-called FPGAs, can also be used to implement a microcomputer (µC) (user programmable gate arrays) and / or can be used, which is also proposed in WO-A 03/098154, the so-called SOPC-systems (systems on a programmable chip). In addition, in another embodiment of the invention, the measuring electronic unit contains at least one display element for the human-machine interface, located, for example, in the immediate vicinity of the measuring electronic unit and supporting, at least temporarily, communication with this measuring electronic unit, in particular with a microcomputer, possibly provided therein, for visual indication of at least the measured density value. The display element for the human-machine interface, in this case, can also be implemented in the form of a combined display and service element, which makes it possible, in addition to visualizing the measured values, also entering user service commands that specify parameters and / or control the measuring electronic unit .

The measuring electronic unit periodically generates, based on the temperature measurement signal, for example, also using, if necessary, the provided microcomputer, a measured temperature value (X _ϑ ), in particular a digital value representing the local temperature of the medium as an instantaneous value, in particular the temperature of the medium in place of the temperature measurement, and / or that the measuring electronic unit periodically generates, based on a signal (x _p) of the pressure measurement, e.g., in turn, to-Application iem, if necessary, provided the microcomputer, the measured value (X _p) pressure, in particular a digital value representing the instantaneous value of the pressure prevailing in a medium, in particular pressure measurement site.

At least for the case described above, in which the measuring system is formed by two, or also more independent measuring devices, in the case of the measuring system according to the invention, also the measuring electronic unit can be implemented by means of a suitable connection, by wires and / or wirelessly, the electronic unit of individual measuring devices, thus forming subcomponents of the measuring electronic unit, and can, as a result, also be compiled in a modular principle. The measuring electronics can communicate with a temperature sensor and / or a pressure sensor, for example, via a fieldbus, in particular a serial fieldbus. As an alternative to a distributed design, the measuring electronic unit can, however, if necessary, also be implemented in the form of a single module into which the measuring signals generated by pressure and / or temperature sensors are supplied directly.

If necessary, at least two electronic units of the measuring devices, or subcomponents of the electronic unit 100 ₁ , 100 ₂ , must be so interconnected by a method known to specialists in this field of technology that during operation of at least one of these two electronic units 100 ₁ , 100 ₂ measuring devices, respectively, the issued measurement data could be transmitted in at least one direction to another unit, thus functioning as a main electronic unit. This can be implemented by a method known to specialists in this field of technology, in the form of measuring signals encoded by their voltage, their current and / or their frequency, and / or in the form of measured values, dressed in the form of digitally encoded telegrams, for example, by HART® - MULTIDROP or in batch-exclusive mode. However, instead, data connections supported in two directions between two electronic units 100 ₁ , 100 ₂ measuring devices can also be used to transmit locally defined, measured variables, in each case, respectively, to another electronic unit 100 ₁ , 100 ₂ measuring devices, for example, via an external fieldbus. To make the necessary connection between the two electronic units 100 ₁ , 100 ₂ measuring devices, you can usefully use standard interfaces, respectively adopted in the technology of industrial measurements and automation, such as, for example, 4-20 mA current loops transmitted via wires, if necessary also in combination with HART® or other applicable fieldbus protocols and / or corresponding radio connections.

At least one measuring electronic unit 100 ₁ , 100 ₂ , in addition, is designed so that it supports, at least temporarily, communication, as shown schematically in figure 1, with the data processing system described above with respect to it, and in such a way that, at least during a normal measuring operation, the measured values periodically determined by the measuring system are transmitted, if necessary, even in the form of a digitally encoded telegram, in as short a time as possible, and / or real-time data processing system. To register the measured values transmitted from the measuring electronic unit, the data processing system 2 is further provided with at least one evaluating circuit 80, which maintains, at least temporarily, appropriate communication with it. The data processing system 2 may, for example, be part of an automatic control unit located adjacent to the process or also a remote process control system having a plurality of process control computers and / or digital programmable logic controllers that are spatially distributed within an industrial enterprise and interconnected via an appropriate data network, in particular also by digital fieldbus. Similarly, the data processing system can be connected to additional measuring devices and / or to control devices, such as, for example, valves or pumps involved in the process. The data processing system further comprises at least one field bus (FB), in particular a serial field bus, designed to transmit digital measurement data and / or operating data. This at least one field bus (FB) may, for example, be a bus operating in accordance with one of the standards adopted in the field of automation of production processes, such as for example FOUNDATION FIELDBUS, PROFIBUS, CANBUS, MODBUS, RACKBUS - RS 485 or like them. The above evaluation circuit 80 is connected to at least one field bus specifically for transmitting measured values received in the form of digital measurement data from the measurement system. Depending on how the field bus and the measuring electronic unit are implemented, the latter can be connected to the data processing system 2 either directly or by means of an adapter that accordingly converts the signal carrying the measured value.

The measuring electronic unit and the data processing system 2, located, if necessary, at a considerable spatial distance from it, in a further improvement of the invention are electrically connected to each other by means of at least one pair (2 L) of wires through which during operation at least temporarily, current (I) flows, in particular a variable current (I). This current can be supplied, for example, from an external source of electric energy or power 70 provided in this superior data processing system. During operation, the power supply 70 provides at least one supply voltage (U _V ), in particular a unipolar supply voltage, generating current (I) flowing in a pair (2 L) of wires. The power supply, in this case, can be, for example, a battery and / or a circuit of a constant or alternating current voltage source, fed through an internal power supply network of the enterprise. To connect, in particular, with the possibility of disconnecting this at least one pair (2 L) of wires to the measuring electronic unit 100a, and thus to the measuring system 1 itself, such a unit further comprises at least one available from outside the terminal pair.

For the above-described case of a measuring electronic unit assembled on a modular basis from separate subcomponents, each of the subcomponents 100 ₁ , 100 ₂ can, for example, be connected separately to an external power supply, for example, also through the aforementioned 4-20 mA current loop. However, as an alternative to or in addition to this, one of the subcomponents 100 ₁ , 100 ₂ can also be connected to the other subcomponent so that it can, at least temporarily, supply such other subcomponent with electrical energy.

The measuring electronic unit is also made in such a way that the measured values generated internally in the measuring system, whether now, the measured values of a single recorded measured variable or the measured values of various recorded measured variables, such as, for example, determined density and determined mass flow, are transmitted at least partially through this at least one pair (2 L) of wires of the data processing system 2. A pair (2 L) of electrical wires, in this case, can be part of the so-called two-wire current loop, which has proven itself in industrial measurement technology. Then, for this case, on the one hand, the measured values generated at least temporarily are transmitted through this single pair (2 L) of wires to a higher data processing system in the form of a load modulated current (for example, via traditional communication circuits) in the loop, in particular, a clocked or continuously changing current in the loop, and on the other hand, through this pair (2 L) of wires, the measuring electronic unit and, thus, the measuring system are supplied by means of a corresponding, in particular, clocked a DC current, at least temporarily and / or at least partially, by electric energy or electric power (I _N · U _N ).

The measuring electronic unit 100 is also intended to generate, during operation, a plurality of measured values, in particular digital measured values representing at least partially this at least one measured variable, and to transmit such values, at least in part, via the terminals and a pair (2 L) of wires appropriately connected therewith to the connected data processing system 2 in a form suitable for the data processing system 2. If necessary, the measuring system, in this regard, can be further improved so that the measuring electronic unit 100 and the data processing system 2 are also connected to each other by means of at least one additional second pair of wires (not shown in the drawing) ) through which, during operation, at least temporarily, an electric current flows. For this case, the measuring system can additionally transmit internally generated measured values, at least in part, also through an additional pair of wires to the data processing system. As an alternative to this or in addition to this, the measuring system and the data processing system can also communicate with each other wirelessly, for example via radio waves. In particular, for this latter case, it may also be preferable to supply the measuring system with electrical energy, in particular also exclusively, by means of an internal and / or external, in particular a replaceable and / or rechargeable battery and / or fuel cell. In addition, the measuring system can be additionally powered, partially or exclusively, by means of power converters using regenerative energy sources and placed directly on the lower level measuring device and / or placed at a distance from it, examples of such power converters are, for example, heat generators, solar panels , wind generators and the like.

The measuring system can communicate via the measuring electronic unit, at least temporarily, with an external service and control module, for example, a portable service module or a programming device provided in the described data processing system, data related to a specific device, such as settings, internal in relation to the measuring device, for the measuring electronic unit and / or diagnostic parameters internal to the measuring system IU. To this end, at least one communication circuit (COM) is further provided in the measuring electronic unit 100, which controls the communication of at least one pair (2 L) of wires. In particular, the communication circuitry is used to convert data related to a particular measuring system to be sent to signals capable of being transmitted via a pair (2 L) of electrical wires, and then to supply such signals to the wires. Alternatively, the communication circuit (COM) may, however, also be designed to receive data related to a particular measuring system, for example, a set of settings to be changed for the measuring electronic unit, sent from the outside via a suitable pair of electrical wires. A communications circuit may, for example, be an interface circuit that operates in accordance with the HART @ - Field - Communications - Protocol (HART Communication Foundation, HART Communication Foundation, Austin, TX) , USA), in which a high-frequency alternating voltage encoded by FM (frequency shift keying) is used as a signal carrier, or, however, also an interface circuit operating in accordance with the PROFIBUS standard (high-speed digital technology bus standard Logical equipment). If necessary, the measuring electronic unit can also additionally have direct access to external processes (for example, in the operating environment of the described data processing system) that communicate with the measuring electronic unit 100 and process the data.

) измерения плотности. Виртуальное место (

) измерения плотности в таком случае, как может быть отнесено к эталонному месту, выбираемому во время работы из множества заданных эталонных мест и, таким образом, быть определенным образом изменяющейся по своему местоположению, так и оно может также сохраняться фиксированным по своему местоположению. По меньшей мере, для последнего случая дополнительный вариант выполнения изобретения предусматривает, что корпус электронного блока с расположенным в нем измерительным электронным блоком размещается в непосредственной близости от виртуального места (

) измерения плотности. Определение виртуального места (

) измерения плотности происходит, в таком случае, путем соответствующего конфигурирования измерительного электронного блока, в частности, вычислительным способом, исполняемым при этом в целях измерения плотности, учитывающего положение и геометрический характер реальных мест (М_р), (M_ϑ) измерения. Предусматривается, что виртуальное место (

) измерения плотности расположено выше по течению от места (М_ϑ) измерения температуры и/или выше по течению от места (М_р) измерения давления. Кроме того, для определения плотности может быть предпочтительным позволить месту измерения плотности совпасть либо с местом измерения температуры, либо с местом измерения давления.The measuring system according to the invention further provides that the measuring electronic unit generates during operation, using at least a temperature measurement signal (x _ϑ ), as well as a pressure measurement signal (x _p ), a measured value (X _ρ ) density in such a way that it represents the instantaneous value of the local density that the current medium actually has in an imaginary reference place (which can also be located at a predetermined distance from the real place of pressure measurement and / whether there is a real place for measuring temperature along the flow axis), determined locally within the process pipeline 20. This is a virtual reference place, due to the lack of an appropriate density sensor in it and in order to distinguish it from actually formed and, thus, real places of change created by means of a temperature sensor and a pressure sensor, referred to as a virtual place (

) density measurements. Virtual Place (

) density measurements in such a case, which can be attributed to a reference location selected during operation from a plurality of predetermined reference locations and, thus, to be changed in a certain way in its location, and it can also be kept fixed in its location. At least for the latter case, an additional embodiment of the invention provides that the housing of the electronic unit with the measuring electronic unit located therein is located in the immediate vicinity of the virtual location (

) density measurements. Definition of a virtual place (

) the density measurement occurs, in this case, by appropriate configuration of the measuring electronic unit, in particular, by a computational method, which is executed in order to measure the density, taking into account the position and geometric nature of the real places (M _p ), (M _ϑ ) measurements. Virtual location (

) the density measurement is located upstream of the location (M _ϑ ) of the temperature measurement and / or upstream of the location (M _p ) of the pressure measurement. In addition, to determine the density, it may be preferable to allow the density measurement site to coincide with either the temperature measurement site or the pressure measurement site.

) измерения плотности, по меньшей мере временно, в частности, в период времени, относящийся к выдаче измеренного значения плотности, и/или периодически, величину, в значительной степени (по меньшей мере, в смысле точности измерения, требуемой для измерения плотности) иную, чем в, по меньшей мере, одном из реальных мест изменения, подающих фактические сигналы измерения, соответственно, в месте измерения температуры и/или месте измерения давления. Следует учесть, что среда в виртуальном месте измерения плотности находится, по меньшей мере временно, в термодинамическом состоянии и/или в состоянии потока, которое (которые) отличается (отличаются) в значительной степени, в частности в степени, значительной для требуемой точности измерения измерительной системы, в том, что касается, по меньшей мере, одной локальный, переменной термодинамического состояния (температуры, давления, плотности и т.д.), от термодинамического состояния среды в месте измерения температуры и/или от термодинамического состояния среды в месте измерения давления. Это пространственное изменение термодинамического состояния и/или состояния потока в текущей среде может возникнуть, как уже было упомянуто, например, в случае сжимаемой среды, среды, реагирующей в технологическом трубопроводе, дополнительно охлаждаемой среды или дополнительно нагреваемой среды. Кроме того, такое изменение термодинамического состояния и/или состояния потока можно также вызвать, позволяя среде, протекать по технологическому трубопроводу, сечение которого сужается и/или сечение которого расширяется вдоль оси потока, таким образом, как это имеет место, например, при применении в технологическом трубопроводе сопел или диффузоров, так что среда ускоряется или замедляется, что, сообразно случаю, сопровождается сжатием или расширением этой среды.The current medium has at least one state variable, for example temperature, and / or pressure, and / or density, and / or Reynolds number (Re), which (which), individually or together, accepts (accepts) virtual location (

) measuring the density, at least temporarily, in particular during a period of time related to the issue of the measured density value, and / or periodically, a value substantially (at least in terms of the measurement accuracy required for density measurement) different, than in at least one of the real places of change, giving the actual measurement signals, respectively, at the point of temperature measurement and / or the place of pressure measurement. It should be noted that the medium in the virtual place of density measurement is at least temporarily in the thermodynamic state and / or in the flow state, which (which) differs (differ) to a large extent, in particular, to a degree significant for the required measurement accuracy system, in regard to at least one local, variable thermodynamic state (temperature, pressure, density, etc.), from the thermodynamic state of the medium in the place of temperature measurement and / or from thermodynamic the state of the medium at the place of pressure measurement. This spatial change in the thermodynamic state and / or flow state in the current medium can occur, as already mentioned, for example, in the case of a compressible medium, a medium that reacts in a process pipe, an additionally cooled medium, or an additionally heated medium. In addition, such a change in the thermodynamic state and / or flow state can also be caused by allowing the medium to flow through the process pipe, the cross section of which narrows and / or the cross section expands along the flow axis, in the same way as, for example, when used in the process line of nozzles or diffusers, so that the medium accelerates or slows down, which, according to the case, is accompanied by compression or expansion of this medium.

) плотности, например, в соответствии с одним из упомянутых промышленных стандартов AGA 8, AGA NX - 19, SGERG - 88 IAWPS - IF97, ISO 12213:2006, для представления плотности, которую текущая среда лишь предположительно имеет в виртуальном месте измерения плотности, что объясняется предварительным пренебрежением рассматриваемыми пространственными изменениями в том, что касается термодинамического состояния и/или состояния потока.For this reason, it is additionally provided that the measuring electronic unit, based on the pressure measurement signal, as well as on the temperature measurement signal, first determines the preliminary measured value (

) density, for example, in accordance with one of the mentioned industry standards AGA 8, AGA NX - 19, SGERG - 88 IAWPS - IF97, ISO 12213: 2006, to represent the density that the current medium only supposedly has in the virtual place of density measurement, which due to a preliminary neglect of the considered spatial changes in terms of the thermodynamic state and / or flow state.

) плотности, в таком случае, может выполняться, по меньшей мере временно, в частности, также и для, по меньшей мере частично, газообразных сред, таких как природный газ, воздух, метан, фосген и т.д., на основе формулы:Determination of the preliminary measured value (

) density, in this case, can be performed at least temporarily, in particular also for at least partially gaseous media such as natural gas, air, methane, phosgene, etc., based on the formula:

in which n is the molar mass, z is the gas compressibility coefficient determined in accordance with one of the industry standards AGA 8, AGA NX - 19, SGERG - 88 IAWPS - IF97, ISO 12213: 2006 and / or using a temperature measurement signal and / or pressure measurement signal, and R _M is the relative gas constant of the medium corresponding to the absolute gas constant (R) normalized to the molar mass (n) of the medium, respectively: R / n, with R = 8.3143 J / (K Mol).

) плотности, по меньшей мере временно, в частности, в случае сред, содержащих, по меньшей мере частично, пар, основываясь на формуле:As an alternative to this or in addition to this, the measuring electronic unit can determine the preliminary measured value (

) densities, at least temporarily, in particular in the case of media containing at least partially steam, based on the formula:

in which π _IAWPS-IF97 = X _p / P * _IAWPS-IF97 and γ _IAWPS-IF97 = g _IAWPS-IF97 / (R _M * X _ϑ ), while P *, is a critical pressure related to a particular medium in accordance with industry standard IAWPS - IF97, in particular 16.53 MPa for the case in which the medium to be measured is water, above which the medium to be measured cannot be liquid, ag _IAWPS-IF97 - free enthalpy related to the medium ( Gibbs free energy) according to industry standard IAWPS - IF97.

) плотности и, таким образом, в конце концов, также и для фактического измеренного значения (Х_ρ) плотности, в таком случае, может быть выполнен автоматически и/или в диалоге с пользователем на месте или посредством вышестоящей системы обработки данных - полуавтоматически, при необходимости также с учетом измеренного на текущий момент давления и измеренной на текущий момент температуры и/или в соответствии со способом выбора, предложенным в упомянутом в начале WO - А 2004/023081.The choice of a really appropriate current calculation formula for the preliminary measured value (

) density and, therefore, in the end, also for the actual measured value (X _ρ ) of the density, in this case, can be performed automatically and / or in dialogue with the user on the spot or through a superior data processing system - semi-automatically, at necessary also taking into account the pressure measured at the current moment and the temperature measured at the current moment and / or in accordance with the selection method proposed in the aforementioned WO-A 2004/023081.

In a preferred embodiment of the invention, it is provided that the measuring electronic unit provides a measured density value, also applying at least one numerical correction coefficient (K), for example, a digitally stored correction factor that corresponds to local variability related to a particular a measuring system and a specific medium and arising along the axis of the flow of the medium for at least one variable of the thermodynamic state of the medium, in particular the temperature s, most pressure or density, and / or that corresponds to a local variation related to a particular measurement system and particular environment and emerging along the axis of flow for a Reynolds number of the flowing medium.

The aforementioned local variability and, as a result, the correction coefficient (K), in this case, can be determined in advance, at least for measuring systems with remaining constant conditions, and / or, during operation, for example, taking into account the environment, in fact to be measured, in particular, its chemical composition and / or its thermodynamic properties. The determination of the correction factor (K) can occur, for example, during calibration of the measuring system using a known reference medium and / or during start-up of the measuring system at the place of operation. For certain options, in particular for media whose chemical composition remains constant and whose thermodynamic properties remain constant, it may be sufficient to determine this at least one correction factor (K) at least once, only during start-up measuring system. However, in the case of media that change significantly during the operation of the measuring system, in terms of their composition and / or thermodynamic properties, if necessary also as a result of replacing such a medium, it can be very useful for the measuring electronic unit to determine the correction factor (K) periodically also after start-up, during operation of the measuring system. The determination of the correction coefficient (K), in this case, can be performed on the basis of a specific heat capacity (c) determined in advance with a user, locally or remotely, and / or in a manner external to the measuring electronic unit (c _p ) the current environment. For example, the specific heat (c _p ) or also other parameters for determining the medium to be measured at a given moment in time can be transferred from the data processing system to the measuring electronic unit and, thus, also to the measuring system.

The measuring electronic unit contains, especially for simplifying the determination of the correction factor (K), at least one data memory 16, in particular a non-volatile data memory, for storing the parameters of the measuring system required for the measuring system to work, in particular, for determining its functionality for measuring and transmitting data. In particular, in this case, it is further provided that the data memory, for example, a data memory in the form of a tabular memory and / or non-volatile memory, stores at least temporarily this at least one correction factor (K), if necessary, This is also the case when the measuring electronic unit is turned off. For example, the data memory may also store for this purpose a plurality of correction factors defined for different environments and / or for various installation circumstances, so that the measuring electronic unit can choose from at least one of the many correction factors stored in the data memory a correction factor (K) suitable for the current time, taking into account the environment available at the current time, as well as the circumstances of the installation at the current time.

In particular, also for determining the correction coefficient (K), the data memory preferably stores at least temporarily at least one parameter (SP _M ) of the measuring system related to the first view, which determines exclusively the medium to be measured at the current time and that the measuring electronic unit determines the measured value (X _ρ ) of the density using at least this at least one parameter (SP _M ) of the measuring system related to the first view. The parameter (SP _M ) of the measuring system related to the first type can be, for example, the specific heat (c _p ) of the medium to be measured at the current time, the molar mass (n) of the medium and / or the number (f) of vibrational degrees of freedom atoms or molecules of the medium, which is determined by the molecular structure of the medium, and / or the parameters derived from them, such as, for example, the coefficient of real gas or also the gas compressibility, if necessary, also determined in accordance with one of the industry standards AGA 8, AGA NX - 19, SGE RG - 88 IAWPS - IF97, ISO 12213: 2006. Thus, in order to determine the medium to be measured at the current moment of time, two or more of these parameters (SP _M ) of the measuring system belonging to the first type, having different dimensions and / or units, can be stored in the data memory, respectively.

In a preferred embodiment of the invention, it is further provided that the data memory stores at least temporarily at least one parameter (SP _ME ) of the measuring system, related to the second view, defining as the medium to be measured at the current time, so and also the instant circumstances of the installation of the measuring system, and that the measuring electronic unit determines the measured value (X _ρ ) of the density, using at least the parameter (SP _ME ) of the measuring system related to the second type, and, in particular, however, also applying the parameter (SP _M ) of the measuring system related to the first view. The circumstances of the installation, in this case, are set, at least to the extent that they are important for determining the measured density value, by the location (relative to each other) of the place (s) of pressure, temperature and density measurement, as well as , in each case, by the shape and size of the process pipeline in the area of the place (s) of pressure, temperature and density measurement. Consequently, the parameter (SP _ME ) of the measuring system related to the second view can, for example, be part of a set of parameters that reflect information about the measurement locations with regard to their actual locations and the actual nature of the process pipeline in the area of the places of change, as well also about the thermodynamic properties of the medium to be measured at the current moment in time, or it can also be a numerical value of a complex parameter that takes such effects into account, we finally determine of, for example, experimentally and / or empirically, during the first operation of the measuring system, possibly also with the use of the parameter (SP _M) of the measuring systems belonging to the first type.

In addition, the measuring electronic unit receives, at least temporarily, in particular in the form of telegrams from the data processing system and / or determined in the shortest time, the numerical values of the parameters for the parameters (SP _M , SP _ME ) of at least one medium , to be measured, and / or measuring system, determining the instant circumstances of the installation of the measuring system, for example, respectively, heat capacity (c _p ) for the medium to be measured at the current time and / or in the future. The heat capacity (c _p ) or another system parameter (SP _M ) of the system related to the first type, which can also be transferred in the same way, in this case, can be determined in advance by means of an appropriate measurement performed, for example, by the density measurement site and / or also external to measuring system in a way and / or by input from the user, if necessary also using a higher data processing system. In addition, in the measuring system according to the invention, therefore, it is also provided that the measuring electronic unit, supporting at least temporarily, by wire or radio communication with the electronic data processing system, transmits the measured density value to the data processing system, and / or the measuring electronic unit, at least temporarily, receives from the data processing system numerical values of the parameters, in particular in the form of a standardized telegram, for the medium to be measured at the moment time, for example, respectively, the parameters (SP _M ) of the measuring system related to the first type, determining its thermodynamic properties and / or its chemical composition. If required, it is also possible to determine, by means of a data processing system, the parameters (SP _ME ) of the measuring system related to the second type and to transmit such parameters in the form of numerical values of the parameters directly to the measuring electronic unit.

For the described case, in which the measuring electronic unit should automatically determine during operation, at least temporarily, based on the parameters (S _M ) of the system related to the first type, the specific heat (with _p ) of the medium to be measured at the current time, such a determination can be made, for example, based on the formula:

in which n represents the parameter of the measuring system - the molar mass, R - the absolute gas constant, with R = 8.3143 J / (K · mol), and f - the parameter of the measuring system - the number of vibrational degrees of freedom of atoms or molecules of the medium to be measurement at the current time.

Preferably, the correction factor is determined solely by the medium to be measured at the current time, in particular, its chemical composition, as well as the physical parameters directly derived from it, as well as a specific embodiment of the measuring system in terms of installation dimensions and installation positions of individual places of change, as well as the size and shape of the process pipeline in the area of places of change, so that, in the end, it is largely n independent of actually measured measured variables, pressure and temperature.

Due to the fact that the change in the thermodynamic or flow state of the current medium, and at the same time the measurement accuracy of such measuring systems, can also be determined jointly by the actual flow rate of the medium, the preferred embodiment of the invention furthermore provides that the measuring electronic unit determines a measured value (X _ρ) density, applying, at least, the value (X _K) density correction determined during operation and the like depending on the flow rate Reda, as well as from local temperature prevailing at the place of the temperature measurement. This density correction value (X _K ), in this case, is embodied in such a way that it corresponds to the instantaneous local variability of at least the variable thermodynamic state of the medium, in particular, such a variable that depends on the medium to be measured at the current time , as well as from the instant circumstances of the installation, and / or which corresponds to the instantaneous local variability of the Reynolds number of the current medium, in particular, such variability, which is a consequence of the medium and / or measurement design system and takes place along the axis of the flow in the measuring system.

At least temporarily, in the measuring electronic unit, the corresponding measured velocity value (X _v ) is available, representing in the form of an instantaneous value, as close to the current moment of time as possible, the flow rate of the medium flowing in the measuring system.

Then, using the measured value (X _v ) of the speed and the measured value (X _ϑ ) of the temperature, as well as the correction coefficient (K) already mentioned, the density correction value (X _K ) can be determined using the measuring electronic unit based on the formula:

) плотности посредством вычислительного алгоритма, основанного на расчетной формуле (1) и/или на расчетной формуле (2), измеренное значение (Х_ρ) плотности для виртуальной измеренной плотности может быть очень просто и быстро определено с применением обоих значений из числа: предварительного измеренного значения (

) плотности, а также, дополнительно, значения (X_K) коррекции плотности, при помощи формулы:At least for the case described above, in which the measuring electronic unit 100 determines a preliminary measured value (

) density using a computational algorithm based on calculation formula (1) and / or calculation formula (2), the measured value (X _ρ ) of the density for the virtual measured density can be very easily and quickly determined using both of the following values: preliminary measured values (

) density, and, in addition, the values (X _K ) of the density correction, using the formula:

Accordingly, in a preferred embodiment of the invention, the measuring electronic unit is configured so that it determines the measured density value (X _ρ ) using the above formulas (4), (5), like (1) or 2, at least temporarily, based on the formula:

and / or, at least temporarily, based on the formula:

) плотности и измеренного значения (Х_ρ) плотности, в частности, таких значений, определенных в соответствии со стандартами в вышеупомянутом смысле, и также выдает такую погрешность в форме численного значения погрешности плотности. Недопустимо высокое расхождение между предварительным измеренным значением (

) плотности и измеренным значением (Х_ρ) плотности или между значением (X_K) коррекции плотности и соответствующим эталонным значением может, например, быть отнесено за счет ошибочного задания параметров измерительного электронного блока, или неожиданного изменения среды, подлежащей измерению, и/или повреждения установки, содержащей технологический трубопровод. Предусматривается, что измерительный электронный блок применяет значение (X_K) коррекции плотности при генерировании измеренного значения (Х_ρ) плотности только тогда, когда оно составляет, по меньшей мере, единицу, в частности лежит в диапазоне от 1 до 1,2. В варианте выполнения изобретения, альтернативном этому, измерительный электронный блок сконфигурирован таким образом, что он применяет значение (X_K) коррекции плотности при генерировании измеренного значения (Х_ρ) плотности только тогда, когда оно составляет, самое большее, единицу, в частности лежит в диапазоне от 0,8 до 1. В дополнение к этому, может быть предпочтительным для пользователя, когда измерительный электронный блок выводит мгновенную погрешность плотности в форме численного значения погрешности плотности и/или сравнивает мгновенную погрешность плотности, по меньшей мере, с одним заранее заданным эталонным значением и, основываясь на этом сравнении, генерирует, временно, сигнал тревоги, который сигнализирует о нежелательном, в частности, недопустимо высоком расхождении между предварительным измеренным значением (

) плотности и измеренным значением (Х_ρ) плотности, например, на месте, посредством элемента отображения интерфейса «человек-машина».In order to check the reliability of the instantly determined measured density value, for example, during the self-test of the measuring system, the measuring electronic unit in the preferred embodiment of the invention periodically compares the density correction value (X _K ) with at least one reference value during operation, relating to a specific predetermined measuring system. With further improvement, it is envisaged that the measuring electronic unit, based on a comparison of the density correction value (X _K ) and the reference value, quantitatively signals the instantaneous deviation of the density correction value (X _K ) from the reference value and / or temporarily generates an alarm signaling about an undesirable, in particular, an unacceptably high discrepancy between the density correction value (X _K ) and the corresponding reference value. As an alternative to this or in addition to this, the measuring electronic unit is also implemented in such a way that it determines, periodically during operation, a density error that corresponds to the deviation, in particular the relative deviation, of the preliminary measured value (

) density and the measured value (X _ρ ) of the density, in particular, such values determined in accordance with the standards in the above sense, and also gives such an error in the form of a numerical value of the density error. Unacceptably high discrepancy between the preliminary measured value (

) of the density and the measured value (X _ρ ) of the density or between the value (X _K ) of the density correction and the corresponding reference value can, for example, be attributed to an erroneous setting of the parameters of the measuring electronic unit, or an unexpected change in the medium to be measured, and / or damage installation containing the technological pipeline. It is envisaged that the measuring electronic unit applies the density correction value (X _K ) when generating the measured density value (X _ρ ) only when it is at least one, in particular in the range from 1 to 1.2. In an embodiment of the invention, an alternative to this, the measuring electronic unit is configured so that it applies the density correction value (X _K ) when generating the measured density value (X _ρ ) only when it is at most unity, in particular lies in the range from 0.8 to 1. In addition, it may be preferable for the user when the measuring electronic unit displays an instantaneous density error in the form of a numerical value of the density error and / or compares mg a new density error with at least one predetermined reference value and, based on this comparison, temporarily generates an alarm signal that signals an undesirable, in particular, unacceptably high discrepancy between the preliminary measured value (

) density and the measured value (X _ρ ) of the density, for example, in place, through the display element of the interface "man-machine".

The measuring system additionally provides at least one flow measurement signal (x _v ) influenced by the local flow rate. This is done, in particular, also for the purpose of automatically and in the shortest possible time determining the value (X _K ) of the density correction. In order to supply this at least one flow measurement signal (x _v ), the measuring system is equipped with at least one flow sensor located at the speed measurement location (M _v ) in order to mainly respond to local speed the flow of the medium to be measured, in particular by the flow rate averaged over the cross section of the process pipe, in particular, also by changes in this flow rate. During operation, the measuring electronic unit 100 and the flow sensor, therefore, communicate, at least temporarily, with each other, at least in such a way that the measuring electronic unit has at least temporarily at its disposal a signal (x _v ) flow measurement generated by a flow sensor. In particular, in this case, it is further provided that the measuring electronic unit determines the measured density value (X _ρ ) also using the flow measurement signal. At least for this, the measuring electronic unit communicates, at least temporarily, also with the flow sensor, for example, also via an external fieldbus and / or wirelessly via radio. In addition, it is envisaged that the measured density value is generated by the electronic unit of the measuring device in such a way that it represents the local density of the medium in the area of the flow sensor.

In the embodiment of the invention shown here, at least a flow sensor, in particular, however, also one of the electronic modules of the measuring electronic unit, is made by means of an industrial type measuring device integrated in the pipeline for current media, for example, a device implemented as a compact device. The measuring device integrated in the pipeline comprises at least one carrier pipe which is essentially rigid and sufficiently resistant to pressure through which the medium to be measured flows during operation, in particular a carrier pipe inserted into the route of the process pipe and, therefore, image forming a rectilinear section of this pipeline. The actual flow sensor is appropriately located on and / or in the carrier tube. Depending on the application, the carrier tube can be made, for example, of metal, plastic and / or ceramic.

The flow sensor is preferably made compact measuring device built into the pipeline in the form of a vortex flowmeter inserted into the route of the process pipeline. Such vortex flow meters have traditionally been used for high-precision recording, as a primary physical measured variable, the flow rate and / or volumetric flow rate of flowing media, in particular media with high temperature and / or high pressure.

Figures 3a and 3b show in cross-section a vortex flowmeter, in one case, if you look at it in the direction of flow (Fig. 3a), and in another case, if you look at it in the direction opposite to the direction of flow (Fig. 3b). The vortex flowmeter contains a vortex sensor 30 attached to the pipe wall 21 of the carrier tube 20, serving as a straight section of the process pipe. The vortex sensor 30 protrudes through a bore hole 22 made in the wall 21 of the tube, and serves as a flow sensor in the aforementioned sense. The vortex sensor 30 may, for example, be a vortex sensor with dynamic compensation, equipped with a blade immersed in the medium and a capacitive transducer element detecting its deformations, as is also described in US-A 6003384.

In the inner part of the carrier tube 20, which itself is inserted into the pipeline, for example, by means of corresponding flange connections, in addition, a streamlined body 40 is located along one of the diameters of the carrier tube, which is firmly connected to the carrier tube 20 in diametrically opposite places 41 , 41 * attachments. The center of the bored hole 22 and the center of the attachment site 41 lie on the generatrix of the carrier tube 20. The non-streamlined body 40 comprises a collision surface 42 against which the medium to be measured flows during operation. In addition, the non-streamlined body 40 has two side surfaces, of which only the side surface 43 facing us is visible in FIGS. 3a and 3b. The impact surface 42 and the side surfaces form two dividing edges, of which only two of them are fully visible. the separation edge 44 facing us, while the location of the rear separation edge is seen in FIG. The non-streamlined body 40 shown in FIGS. 3a and 3b has, here, substantially the shape of a straight triangular column, that is, a perpendicular column of triangular cross section. However, if necessary, to perform the measuring system according to the invention, it is also possible to use non-streamlined bodies having a different shape.

The flow of the medium against the impact surface 42 forms a Karman vortex path downstream of the streamlined body in a known manner, in which vortices are alternately separated from each dividing edge and then move downstream in the current medium. These swirls carried away by the flow, in turn, generate local pressure fluctuations in the current medium, and their time-related separation frequency, respectively, their so-called swirl frequency, is a measure for the flow velocity and / or volumetric flow rate of the medium. The pressure fluctuations removed from the carried-out vortices are then converted by means of a vortex sensor 30, formed here by means of a blade and placed downstream of the body of a streamlined shape, into a swirl signal corresponding to the local flow velocity and serving as an electrical signal (x _v ) for flow measurement.

The transducer element 36 provides the aforementioned measurement signal, the frequency of which is proportional to the volumetric flow rate of the current medium.

The vortex sensor 30 is inserted downstream of the non-streamlined body 40 into the bored hole 22 in the pipe wall 21 of the carrier tube 20 and seals the bored hole 22 against the flow of medium from the inside of the carrier tube 20 to the outer surface of the carrier tube 20, which is achieved by screw connection of the vortex sensor 30 with a wall 21. For this purpose, for example, four screws are used, of which the screws 5, 6, 7 are visible in FIGS. 3a and 3b. The parts of the vortex sensor, which are visible in FIGS. 3a and 3b, are a wedge-shaped sensor blade 31 protruding through a bore hole 22 in the tube wall 21 into the interior of the carrier tube 20, and a housing cap 32. The housing cap 32 ends with a extension 322 with an introduction between them having a thin wall of the intermediate portion 323; in this regard, compare also the already mentioned US-A 6003384. The blade of the sensor 31 has main surfaces, of which only the main surface 311 is visible in FIGS. 3a and 3b. The main surfaces are exposed along said generatrix of the carrier tube 20 and form the leading edge 313. The blade 31 the sensor may also have other spatial forms; so, for example, it may have two parallel main surfaces that form two parallel leading edges. The blade 31 of the sensor is shorter than the diameter of the carrier tube 20; in addition, it is rigid to bending and may contain, for example, a blind hole, into which a conversion element in the form of a thermocouple or resistance thermometer can be inserted, which serve to determine the temperature of the medium, if necessary, to generate a temperature measurement signal and, therefore, also to perform the temperature measurement site itself; in this regard, compare the already mentioned US-B 6988418 or US-B 6910387. In order for the blind hole 314 to have a sufficient diameter, wall sections protrude from the main surfaces, such a wall section 315 is indicated in Fig. 3a. Blind hole 314 reaches a place near the leading edge 313 and has a bottom there.

The vortex sensor 30 also includes a diaphragm 33 that covers the bored hole 22 and has a first surface 331 facing the medium and a second surface 332 facing away from the medium; see Figs. 3 and 4. The blade 31 of the sensor is attached to the surface 331, while the element 36 that converts the physical parameter into an electrical signal and reacts to the bending or movement of the blade 31 is attached to the surface 332. The blade 31 of the sensor, the diaphragm 33, as well as its annular edge 333 can be made of a single piece of material, such as metal, in particular stainless steel.

It should be noted here that instead of the vortex flowmeter shown here by way of example, having at least one non-streamlined body protruding into the lumen of the process pipe and immersed in the medium, and at least one downstream flow sensor from this at least one non-streamlined body, in particular, a flow sensor protruding at least partially into the lumen of the process pipe, it is possible to create at least one flow sensor supplying the squeezed flow measurement signal, and therefore, to form a flow measurement site, as such, also use other measuring devices built into the pipeline, equally recognized in the automation technology of the production process, examples of which are, for example, magnetically inductive flow meters, heat flow meters, measuring devices differential pressure flow, ultrasonic flow meters or the like. The flow sensor itself can, in this case, which is also common with such measuring devices, and depending on the implemented measurement principle, be formed by at least an element of electrical resistance, in particular, an element of resistance through which it flows, at least temporarily, heating an electric current; by means of at least one measuring electrode measuring electric potentials, in particular, a measuring electrode in contact with the current medium; by at least one measuring capacitor responsive to changes in the flow parameter; and / or by means of at least one piezoelectric element and / or piezoresistive element. The flow sensor can, especially in the case when a measuring capacitor and / or a piezoelectric or piezoresistive element is used to form the flow sensor, is a sensor that is periodically subjected to mechanical deformations during operation under the influence of a medium flowing in the measuring system to generate a measurement signal, and / or which during operation periodically moves relative to the position of static equilibrium under the influence of a medium flowing in the measuring tube, which is common This is precisely the case, with the exception of the aforementioned in-line measuring devices that measure the flow parameter based on vortices carried away in the stream with the formation of the Karman vortex track, for example, also for such in-line measuring devices that measure the flow parameters of the considered type based on differences pressure. For the latter case, this at least one flow sensor can be formed, for example, by at least one obstruction in the flow path, which narrows the cross section of the process pipe, in particular the flow diaphragm or nozzle, as well as by means of at least one differential pressure sensor, which detects the differential pressure that occurs on this obstacle in the flow path and provides a differential pressure measuring signal. This at least one differential pressure sensor, in this case, can be formed, for example, partially by means of a pressure sensor located in the place of pressure measurement. As an alternative to the aforementioned types of sensor or measuring device, this at least one flow sensor can also be made in combination with a straight section of the process pipe, while vibrations of such a straight section, actively excited from the outside by means of an exciter and / or in a passive manner by the medium itself, are detected by at least one transforming element, recording, for example, electrodynamic or optoelectronic sp particular, mechanical vibrations and the corresponding oscillating signal, thus, as is known, takes place, for example, also in the case of Coriolis mass flowmeters. The Coriolis mass flow meters available on the market are typically pipelines built in the pipeline, which are compact measuring devices in which at least one measuring tube equipped externally with vibration exciters and sensors is inserted through the flanges into the route of the process pipe, forming a straight line a section vibrating at least temporarily during operation.

The use of measuring systems with a measuring device of the aforementioned type integrated in the pipeline thus makes it possible, in addition to the virtually measured density, to determine with high accuracy, if necessary also in real time, other measured variables, in particular mass flow, volumetric flow rate, flow rate, viscosity, pressure, temperature and / or the like.

At least in the case of the use of a flow sensor internal to the measuring system, it is also possible to also determine the aforementioned correction factor (K) directly, in advance, in particular also during the “wet” calibration. For example, the correction factor (K) can be very simply selected so that the formula holds:

) плотности, определяемое для эталонной среды, заданной, по меньшей мере, в том, что касается ее фактической плотности (ρ_Ref), имеет от такой плотности (ρ_Ref) эталонной среды. В результате, ΔХρ может рассматриваться практически также как погрешность измерения, присущая измерительной системе, то есть погрешность измерения, которую предварительное измеренное значение (

) плотности, определяемое посредством самой измерительной системы, несет в себе в виртуальном месте измерения по сравнению с фактической плотностью. Зная предварительное измеренное значение (

) плотности, равно как также и фактическую плотность (ρ_Ref) эталонной среды, можно количественно определить эту погрешность измерения следующим образом:in which ΔXρ corresponds to a deviation determined in advance, in particular, during calibration of the same and / or essentially equivalent measuring system with a known reference medium and / or during the start-up of the measuring system at the place of use, for example, calculated and / or the measured deviation related to a particular measuring system, which is the preliminary measured value (

) the density determined for the reference medium given at least in terms of its actual density (ρ _Ref ) has such a density (ρ _Ref ) of the reference medium. As a result, ΔХρ can be considered almost the same as the measurement error inherent in the measuring system, i.e., the measurement error, which is the preliminary measured value (

) the density, determined by the measuring system itself, carries a virtual measurement location in comparison with the actual density. Knowing the preliminary measured value (

) density, as well as the actual density (ρ _Ref ) of the reference medium, this measurement error can be quantified as follows:

so that the correction factor (K), as a result, must be selected so that it satisfies as accurately as possible the following formula:

However, in addition to this, at least in the case of using a flow sensor internal to the measurement system, it is also quite possible to determine the correction factor (K) experimentally by means of a reference measurement system and corresponding reference media and / or by computer simulation and, based on him, extrapolate further numerical values for correction factors (K) for other measuring systems similar to the reference measuring system, and / or for other media.

The measuring electronic unit, using at least a flow measurement signal, also determines the measured speed value (X _v ), in particular the digital measured speed value (X _v ), which in the form of an instantaneous value represents the flow rate of the current medium, and / or measuring electronic unit, using at least the flow measurement signal, and determines a measured value (X _v) volume flow, for example a digital measured value of the volume flow, which represents an instantaneous value of the specific Removable flow of the current environment. As an alternative to this or in addition to this, the measuring electronic unit, using at least a temperature measurement signal and a pressure measurement signal or a measured density value, as well as a flow measurement signal or a measured volumetric flow rate derived from it, can the operating time, in addition, determine the measured value (X _m ) of the mass flow rate, for example, the digital measured value of the mass flow rate, which represents, as an instantaneous value, the specific mass flow rate or the integ summed, that is, the summed mass flow rate.

To simplify the design of the measuring system and, along with this, to further improve the accuracy of the measured density value, the flow sensor can preferably be placed in such a way that, as is proposed, for example, also in US - B 6988418 or US - B 6910387, at least, the place of flow measurement and the place of temperature measurement, or, as is proposed, for example, also in US Pat. No. 7,075,556, at least the place of flow measurement and the place of pressure measurement at least partially overlap each other, in particular, they coincide them. However, as an alternative, the flow measurement site may, as schematically shown in FIGS. 1 and 2, also be located away from the temperature measurement site and / or the pressure measurement site, for example, upstream of the temperature measurement site and / or higher downstream from the pressure measurement site.

The temperature sensor of the measuring system and / or the pressure sensor, as is proposed, for example, also in US-В 6988418, US-В 6910387 or US-В 6651512, are likewise provided by means of a measuring device integrated in the pipeline containing a flow sensor, for example, built-in piping of the measuring device in the form of a compact measuring device.

In a preferred embodiment, the virtual density measurement site and the flow measurement location are selected such that the medium has a thermodynamic state in the virtual density measurement location corresponding to the thermodynamic state of the medium at the speed measurement location, and / or the medium has a density and measurement location in the virtual measurement location speeds are essentially equal Reynolds numbers. This can, for example, be achieved by defining a virtual density measurement site such that it and the flow measurement location at least partially overlap, in particular, coincide. Accordingly, the measured value of the density should be determined so that it accurately represents the local density of the medium in the area of the flow sensor, and, therefore, also accurately represents the local density of the medium in the place of measurement of speed.

To further simplify the measurement, another embodiment of the measuring system provides that the process pipe is essentially a straight pipe, so that it does not have bends or bends in at least some of its sections, especially in the area between the density measurement site and the place of pressure measurement and / or between the place of measuring density and the place of measuring temperature. In addition, the process pipeline should be implemented in at least some of its sections, especially in the area of the place of temperature measurement and / or in the area of the place of pressure measurement, as a pipeline essentially stable in shape, at least under the action of working pressure , in particular a rigid conduit and / or conduit having a circular cross section.

The aforementioned change is carried out during operation to a large extent in a certain way by providing the process pipeline, at least at the virtual density measurement site, with an internal diameter (D1) different from the internal diameter (D2) of the process pipe at the pressure measurement site. Another embodiment of the invention further provides that the process pipe has an inner diameter (D1) at the virtual density measurement site that is different from the inside diameter (D3) of the process pipe at the temperature measurement site and / or that the inside diameter (D2) of the process pipe at the measurement site pressure differs from the internal diameter (D3) of the process pipe at the temperature measurement site. A detailed examination, thus, as a result, there is a large number of combining possibilities with regard to the location of individual places of change relative to each other, as well as the choice of the internal diameter of the process pipeline at specific measurement sites. The selection of particularly suitable embodiments for this is also shown schematically in FIGS. 4a, 4b, 4c, 4d, 4e, 4f and 4h.

As shown in the figures, it may be preferable to implement the measuring system so that the inner diameter (D2) of the process pipe is larger at the pressure measurement site than the inner diameter (D3) of the process pipe at the temperature measurement site, or, however, also in this way so that the inner diameter (D3) of the process pipe at the temperature measurement site is larger than the inner diameter (D2) of the process pipe at the pressure measurement site. As an alternative to this or in addition to this, the inner diameter (D2) of the process pipe at the pressure measurement site can also be chosen so that it is larger than the inner diameter, (D1) of the process pipe at the virtual density measurement site, and / or the inner diameter (D3) of the process pipe at the temperature measurement site can be selected so that it is larger than the inner diameter (D1) at the virtual density measurement site. In particular, it is further envisaged that the ratio (D3 / D1) of the inner diameters: the inner diameter (D3) of the process pipe at the temperature measurement site to the inner diameter (D1) of the process pipe at the virtual density measurement site is greater than 1.1 and / or less than 5, for example, respectively, lies in the range from 1.2 to 3.1. In addition, at least for this case, it is preferable when the process pipe at the virtual density measurement site has an inner diameter (D1) that is substantially equal to the inside diameter (D2) of the process pipe at the temperature measurement site. In another embodiment, the invention provides that the ratio (D2 / D1) of the inner diameters: the inner diameter (D2) of the process pipe at the pressure measurement location to the inside diameter (D1) of the process pipe at the virtual density measurement site is maintained greater than 1.1 and / or less than 5, for example, respectively, lies in the range from 1.2 to 3.1. For this case, it is preferable that the process pipe at the virtual density measurement site has an inner diameter (D1) that is substantially equal to the inside diameter (D3) of the process pipe at the temperature measurement site.

The differences between the inner diameters (D1), (D2), (D3), respectively, can, depending on the desired configuration, be realized by supplying a process pipeline between at least two of the above mentioned places of change, for example, respectively, between the virtual a density measuring point and a temperature measuring place and / or a pressure measuring place, or also between a temperature measuring place and a pressure measuring place, a straight section realized as a diffuser, in particular a funnel-shaped fuzor having a lumen, expanding in the flow direction, in particular continuously widening in the flow direction, or a straight portion, which is configured as a nozzle, in particular a funnel-shaped nozzle having a lumen narrowing in the flow direction, in particular continuously tapered in flow direction.

In addition, experimental studies have shown that the measurement sites in the preferred embodiment should be positioned or set so that the distance (L21) by which the pressure measurement site is away from the virtual density measurement site is different from the distance (L31) by which temperature measurement is far from the virtual place of density measurement. For example, it can be very preferable for measurement when the distance (L21) by which the pressure measurement location is away from the virtual density measurement location is greater than the distance (L31) by which the temperature measurement location is away from the virtual density measurement location and / or when the distance (L21) by which the place of pressure measurement is distant from the virtual place of measurement of density, and / or the distance (L23) by which the place of pressure measurement is distant from the place of measurement of temperature is larger than the inner diameter (D2) Skog pipeline pressure measurement site. In this case, the distance (L21) and / or the distance (L23), comprising at least three times, in particular more than five times the inner diameter (D2), are recognized as quite suitable.

For additional information on the layout and dimensioning of the process pipe of the measuring system regarding the aforementioned installation lengths and / or ratios of the internal diameters in the case of using a pressure reducing element and / or diffuser, as well as other versions of the process pipe upstream of the flow sensor and / or downstream of the flow sensor, a direct reference is hereby made to previously unpublished applications DE 102006034296.8 and 102006047815.0 of the copyright holder this invention, or similar applications, and their respective disclosures should, therefore, be construed as belonging to this application.

Further studies with the measuring systems according to the invention additionally showed for the locations of the places of temperature, pressure and density changes shown in FIGS. 4a, 4b, 4c, 4d relative to each other, as well as with respect to the aforementioned ratios of the inner diameters, that the density correction value determined for them, at least in accordance with formula (4) and used to determine the measured density value in accordance with formula (1) or 2, must always be greater than one; otherwise, as already mentioned, a malfunctioning measuring system or disruption to the enterprise would have been obtained. Similarly, for the combinations shown in FIGS. 4e, 4f, 4g, and 4h, the density correction value, provided that the same calculation formulas are applied, should always be less than one.

In addition, table 1 shows the combinations with respect to the internal diameters (D1), (D2), (D3), in each case in mm, and the gases selected as the medium, as well as, in each case, respectively, a suitable correction factor (K) in units of measurement K · s ² · m ^-2 , especially suitable for a measuring system with a flow sensor in accordance with the exemplary embodiment shown in FIGS. 2 and 3.

Table 1 Gas D1, D3 D2 TO CH ₄ (n = 16 gmol ^-1 , f = 6) 13.9 24.3 27851,08558 13.9 26.7 26084,12357 13.9 27,2 25671.22129 13.9 28.5 24567.65186 13.9 38.1 17069,51792 13.9 40.9 15350.28348 13.9 41.2 15178,90947 13.9 43.1 14147.85441 24.3 38.1 3086,763684 24.3 40.9 3035,482335 24.3 41.2 3026,384008 24.3 43.1 2957,410639 24.3 49.2 2662,97974 24.3 52.6 2484,170531 24.3 52.7 2478,934254 24.3 54.5 2385,462689 38.1 49.2 448,2000215 38.1 52.6 487,9209744 38.1 54.5 500.3838513 38.1 73.7 459,369374 38.1 78 435.8925863 38.1 78.1 435,337907 38.1 82.5 410,9043438 49.2 73.7 183.0929623 49.2 78 183.4977725 49.2 78.1 183,4687956 49.2 82.5 180.8940523 49.2 97 162,4571647 49.2 102.3 154,3167919 49.2 102,4 154.1619225 49.2 107.1 146,8997624 73.7 97 32,98911974 73.7 102,4 35.0370316 73.7 107.1 36,01526944 73.7 146 32,12475476 73.7 151 31,10798557 73.7 154.2 30,45138942 73.7 159.3 29,40598339 97 146 12,12975471 97 151 12.16106709 97 154.2 12,14098846 97 159.3 12.05687371 97 199.9 10.30674712 97 202.7 10.16121596

97 206.5 9,963705636 97 207.3 9.922187549 146 199.9 2,245529752 146 202.7 2,273600656 146 206.5 2,304852917 146 207.3 2,310502276 146 248.8 2,317268815 146 254.5 2.291734778 146 258.8 2,2702775 146 260,4 2.261877863 Natural gas (n = 16 ..., 40 g · mol ^-1 , depending on the composition, f = 6) 13.9 24.3 31170,01324 13.9 26.7 29190.34938 13.9 27,2 28727,93943 13.9 28.5 27492,24479 13.9 38.1 19099,80535 13.9 40.9 17175,91318 13.9 41.2 16984,14311 13.9 43.1 15830.39114 24.3 38.1 3455.020015 24.3 40.9 3397,337203 24.3 41.2 3387,128821 24.3 43.1 3309,793458 24.3 49.2 2980,007098 24.3 52.6 2779.822049 24.3 52.7 2773,96038 24.3 54.5 2669,329455 38.1 49.2 501.8495813 38.1 52.6 546,2444885 38.1 54.5 560,159696 38.1 73.7 514,0710105 38.1 78 487.7826811 38.1 78.1 487.1616486 38.1 82.5 459.8077209 49.2 73.7 204,9496071 49.2 78 205,3864268 49.2 78.1 205,3536589 49.2 82.5 202,458931 49.2 97 181,8004079 49.2 102.3 172.6858252 49.2 102,4 172.5124389 49.2 107.1 164.3825333 73.7 97 36.93625048 73.7 102,4 39,22468158 73.7 107.1 40,31654938 73.7 146 35,94964274 73.7 151 34,81116896 73.7 154.2 34.07605503 73.7 159.3 32.90573249 97 146 13,57764009 97 151 13.61203427 97 154.2 13,58918743 97 159.3 13.49451405 97 199.9 11,53365739 97 202.7 11,37072445 97 206.5 11,14960825 97 207.3 11,10312955 146 199.9 2,5139906 146 202.7 2,545346756 146 206.5 2,580243371 146 207.3 2,586549405 146 248.8 2.593473866 146 254.5 2,564840534 146 258.8 2,540788021 146 260,4 2.531374101 H ₂ O (n = 18 gmol ^-1 , f = 6) 13.9 24.3 31256.24144 13.9 26.7 29271.0454 13.9 27,2 28807,34836 13.9 28.5 27568,21927 13.9 38.1 19152.54293 13.9 40.9 17223,33422 13.9 41.2 17031,03432 13.9 43.1 15874.09507 24.3 38.1 3464,588763 24.3 40.9 3406,738816 24.3 41.2 3396,501521 24.3 43.1 3318,948505 24.3 49.2 2988.242826 24.3 52.6 2787.502227 24.3 52.7 2781,624305 24.3 54.5 2676,703394 38.1 49.2 503,2441144 38.1 52.6 547,7602846 38.1 54.5 561,7131315 38.1 73.7 515,492087 38.1 78 489,1306726 38.1 78.1 488.5079154 38.1 82.5 461.07809 49.2 73.7 205,5175663 49.2 78 205,9551717 49.2 78.1 205,9223044

49.2 82.5 203,0192259 49.2 97 182.3029139 49.2 102.3 173,1630088 49.2 102,4 172.9891412 49.2 107.1 164.8366844 73.7 97 37.03884498 73.7 102,4 39,33351491 73.7 107.1 40,42832654 73.7 146 36,04900682 73.7 151 34,90736955 73.7 154.2 34,1702149 73.7 159.3 32,99664598 97 146 13,61526406 97 151 13,64973647 97 154.2 13,62681665 97 159.3 13.53186744 97 199.9 11,56552973 97 202.7 11,40214452 97 206.5 11,18041482 97 207.3 11,1338072 146 199.9 2,52096787 146 202.7 2,552409208 146 206.5 2,587400279 146 207.3 2,593723327 146 248.8 2,600650057 146 254.5 2,571936044 146 258.8 2,547815996 146 260,4 2,538375687 Air (n = 29 gmol ^-1 , f = 5) 13.9 24.3 50338,90921 13.9 26.7 47124,38089 13.9 27,2 46375,14885 13.9 28.5 44,374.58191 13.9 38.1 30815,23069 13.9 40.9 27710,05332 13.9 41.2 27400,56851 13.9 43.1 25538,71377 24.3 38.1 5583,208016 24.3 41.2 5470,96068 24.3 43.1 5344,897321 24.3 49.2 4810,117614 24.3 52.6 4486,285526 24.3 52.7 4476.808075 24.3 54.5 4307.671069 38.1 49.2 812.4565419 38.1 52.6 883,65719 38.1 54.5 905,8569033

38.1 73.7 829,8882553 38.1 78 787.3215533 38.1 78.1 786,316573 38.1 82.5 742.0716954 49.2 73.7 331.3026455 49.2 78 331.8738927 49.2 78.1 331,8181848 49.2 82.5 327,0348906 49.2 97 293.4714706 49.2 102.3 278,7184046 49.2 102,4 278,437899 49.2 107.1 265,289832 73.7 97 59.78309893 73.7 102,4 63,449488 73.7 107.1 65,18836646 73.7 146 58,03092489 73.7 151 56,18799037 73.7 154.2 54,9986214 73.7 159.3 53,10590103 97 146 21.94754221 97 151 21,99771435 97 154.2 21.95771667 97 159.3 21,80041304 97 199.9 18,61596382 97 202.7 18.35235887 97 206.5 17,99471318 97 207.3 17,91954828 146 199.9 4,067220274 146 202.7 4,117361285 146 206.5 4.173054129 146 207.3 4,183100739 146 248.8 4,188923875 146 254.5 4,142218763 146 258.8 4,103061713 146 260,4 4.087749585

Claims (44)

1. A measuring system for measuring the density flowing along the technological line; varying along the imaginary axis of the flow of the measuring system in relation to the thermodynamic state, in particular of at least partially compressible medium, containing at least one installed in place (M _ϑ ) temperature measurement primarily reacting to local temperature (ϑ) of the flowing medium a temperature sensor adapted to generate at least one measurement signal (X _θ) the temperature is influenced by the local temperature of the medium, at least one mounted nny in place of (M _p) of the pressure measurement initially responds to local, in particular the static pressure (p) which flows past the fluid pressure sensor adapted to generate at least one undergoing local pressure influence (p) in the measurement medium the measurement signal (X _p) of pressure, and mounted in the primary flow measurement site responsive to the local parameter of flow of the medium flow sensor adapted to generate at least one lock is influenced of a flow parameter of a flow measurement signal and at least temporarily connected to at least temperature and pressure sensors and also to a flow sensor, a measurement electronic unit, which is configured to, by means of a temperature measurement signal and at least a pressure measurement signal determination of the preliminary measured value (

) a density representing the density that the flowing medium only supposedly has in the virtual place of density measurement, the measuring electronic unit being configured to periodically generate, based on the temperature measuring signal, a measured temperature value (X _ϑ ) that represents the local temperature of the medium at a given moment, measuring electronic unit by means of at least a measuring signal of the flow is configured to determine the measured value (X _v ) of the velocity, which represents the current velocity of the medium, and the measuring electronic unit by means of the measured value (X _v ) of the velocity, as well as the measured value (X _ϑ ) of the temperature, is configured to determine at least one dependent as the flow velocity of the medium and the prevailing at the measurement site local temperature temperature obtained to the time of passage of the correction value (X _K) density, wherein the electronic measuring unit by means of preliminary measurements Nogo values (

) density, as well as at least one correction value (X _K ) of density made with the possibility of at least temporary formation of at least one different from the preliminary measured value (

) the density of the measured value (X _ρ ) of the density that currently represents the local density (ρ) that the flowing medium has in a virtual place (

) density measurements, more accurately than the preliminary measured value (

) density. 2. The system according to claim 1, in which the measuring electronic unit is configured to periodically determine during operation a density error corresponding, in particular, to a relative deviation from the preliminary measured value (

) density and the measured value (X _ρ ) of the density, in particular, with the possibility of issuing a density error at the moment in the form of a numerical value of the density error, and / or comparing with at least one predetermined reference value and based on this comparison of the time supply an alarm signaling an undesirable, in particular, unacceptably high variance between the preliminary measured value (

) density and the measured value (X _ρ ) of the density. 3. The system according to claim 1 or 2, in which the measuring electronic unit is configured to use the correction value (X _K ) of the density when generating the measured value (X _ρ ) of the density only when it is at most one, in particular in the range from 0.8 to 1. 4. The system according to claim 1 or 2, in which the measuring electronic unit is configured to periodically compare when operating the density correction value (X _K ) with at least one predetermined reference value, in particular, such that the measuring electronic unit Based on the comparison of the correction value (X _K ) of the density and the reference value, it is possible to quantitatively signal the deviation at the moment of the correction value (X _K ) of the density from the reference value and / or the temporary supply of Evogi, indicating an undesirable and / or unacceptably high dispersion between the correction value (X _K ) of the density and the corresponding reference value. 5. The system according to claim 1 or 2, in which the measuring electronic unit contains, in particular, a non-volatile data memory in which at least one parameter (SP _M ) of the system specifying only the specifically measured medium is stored in particular, the specific heat c _{p of the} specifically measured medium, the molar mass n of the medium and / or the number f of vibrational degrees of freedom of its atoms or molecules determined by the molecular structure of the medium. 6. The system according to claim 5, in which the measuring electronic unit is configured to determine the measured value (X _ρ ) of the density by means of at least one specifying only a specifically measured medium parameter (SP _M ) of the system. 7. The system according to claim 1 or 2, in which the measuring electronic unit contains, in particular, a non-volatile data memory in which at least temporarily stores at least one medium specifying specifically measured by the system and the installation position of the system in currently parameter (SP _ME) system, wherein the installation position is also determined by arrangement of the pressure measuring points, temperature and density with respect to each other, and accordingly the shape and size of the process line in a zone months and measuring the pressure, density and / or temperature. 8. The system according to claim 7, in which the measuring electronic unit is configured to determine the measured value (X _ρ ) of the density using at least one specifying the medium specifically measured by the system and the situation of the system’s installation at the moment (SP _ME ) system. 9. The system according to claim 1 or 2, in which the measuring electronic unit, at least temporarily, in particular by wires and / or by radio is connected to the data processing system, in particular, via a field bus. 10. The system according to claim 9, in which the measuring electronic unit is configured to transmit the measured density value to the data processing system, and / or the measuring electronic unit is configured to at least temporarily receive from the data processing system numerical parametric values specifying specifically medium to be measured, in particular its thermodynamic properties and / or its chemical composition, parameters (SP _M ), in particular specific heat c _{p of the} medium specifically measured, molar mass n is specifically measured medium and / or the number f of vibrational degrees of freedom of atoms or molecules of a specifically measured medium, and / or the measuring electronic unit is connected to the electronic data processing system via, in particular, a serial field bus. 11. The system according to claim 1 or 2, in which the measuring electronic unit is configured to periodically generate, based on the pressure measuring signal, a measured value (X _p ) of pressure, in particular digital, which represents the pressure currently prevailing in the medium, in particular in place of pressure measurement. 12. The system according to claim 1 or 2, in which the flow parameter represented by the flow signal of the flow sensor is a flow velocity of the medium measured over the cross section of the process line. 13. The system according to claim 1 or 2, in which the medium has a thermodynamic state in the virtual place of density measurement corresponding to the thermodynamic state of the medium at the place of change of speed, and / or the virtual place of density measurement and the place of flow measurement, at least partially overlap, in particular, and / or the place of measuring the temperature and the place of measuring the flow are at least partially overlapped, in particular they are combined and / or the place of measuring the pressure and the place of measuring the flow, at least partially overlap are connected, and / or the measuring electronic unit is connected to the flow sensor via, in particular, a serial field bus and / or wirelessly via radio, and / or wherein the measured density value represents the local density of the medium in the area of the flow sensor. 14. The system according to claim 1 or 2, in which the measured value (X _v ) of the speed is digital. 15. The system according to claim 1 or 2, in which the measured value (X _ϑ ) of the temperature is digital. 16. The system of clause 15, in which the measuring electronic unit is configured to determine the correction value (X _K ) of the density by means of the measured value (X _v ) of the speed and the measured value (X _ϑ ) of the temperature. 17. The system according to claim 1 or 2, in which the measuring electronic unit is configured to generate a measured density value also by means of at least one digital compensation factor (K) stored, in particular, in digital form, which corresponds to the calculated in particular, previously and / or during operation occurring along the flow axis of the measuring system of local variability of at least one parameter of the thermodynamic state of the medium, in particular temperature, pressure or density, and / or calculated, in particular, pre-and / or operation that occurs along the flow axis of the measuring system of the local variability of the Reynolds number of the flowing medium. 18. The system according to clause 16, in which the measuring electronic unit is configured to determine the correction value (X _K ) density also by at least one pre-calculated, in particular, stored in digital form compensation factor (K), in particular based on the rule:

19. The system according to 17, in which at least one compensating coefficient (K) is determined taking into account the specifically measured medium, in particular its composition and / or thermodynamic properties, in particular, during calibration of the measuring system with a known reference medium and / or during commissioning of the measuring system on site. 20. The system according to claim 19, in which the measuring electronic unit is configured to determine at least once the compensation factor (K) during the start-up of the measuring system in operation, and / or wherein the measuring electronic unit is configured to determine the compensating coefficient (K) during operation of the measuring system periodically, in particular, together with a change in at least one chemical property of the medium to be measured or its replacement with another, and / or the measuring electronic unit is made with the ability to determine at least one compensating coefficient (K) using a predetermined, in particular, dialogue with the user and / or outside the measuring electronic unit of the specific heat Cp of a particular medium. 21. The system according to 17, in which the measuring electronic unit contains, in particular, in the form of a tabular memory and / or non-volatile data memory, which stores at least one compensation factor (K). 22. The system of claim 21, wherein the data memory stores a plurality of compensating coefficients previously computed for various environments and / or embedding situations. 23. The system according to item 22, in which the measuring electronic unit is configured to select at least one compensating coefficient (K) from the set of compensating coefficients stored in the data memory, taking into account a specific environment and a specific installation position. 24. The system according to 17, in which the compensating coefficient (K) is selected so that it satisfies the rule:

where ΔХρ corresponds previously, in particular, during the calibration process with the same and / or basically the same type of measuring system as the known reference medium and / or during the start-up of the measuring system in operation, identified on the spot, for example, calculated and / or measured specific for measuring system deviation, which is the preliminary measured value (

) the density detected for a specific density, at least with respect to its specific density ρ _{Ref of the} reference medium, has from the same density ρ _{Ref of the} reference medium. 25. The system according to paragraph 24, in which the compensating coefficient (K) satisfies the rule:

26. The system according to 17, in which the measuring electronic unit is configured to determine at least a pre-measured value (X _ρ ) of the density based on the rule:

where n is the molar mass, z is the real gas coefficient of the medium calculated according to one of the industry standards AGA 8, AGA NX-19, SGERG-88 IAWPS-IF97, ISO 12213: 2006 and / or by means of a measuring signal of temperature and / or pressure, a R _M is the relative gas constant of the measured medium, which corresponds to the absolute gas constant R / n normalized by the molar mass n of the medium at R = 8.3143 J / (K mol). 27. The system according to 17, in which the measuring electronic unit is configured to determine at least a pre-measured value (X _ρ ) of the density based on the rule:

where P * is the medium-specific critical pressure according to the industry standard IAWPS-IF97, in particular 16.53 MPa, if the medium being measured is water above which this medium cannot be liquid in any case, ag _IAWPS-IF97 - environment-specific free enthalpy (Gibbs free energy) according to industry standard IAWPS-IF97. 28. The system of claim 12, wherein the measuring electronic unit is at least temporarily connected to the flow sensor, and wherein the measuring electronic unit is configured to determine a measured value (X _v ) of the volumetric flow rate by at least a measuring flow signal , in particular digital, which represents the fraction of the volumetric flow rate of the flowing medium at the moment. 29. The system according to claim 1 or 2, in which the measuring electronic unit is configured to use the correction value (X _K ) of the density when generating the measured value (X _ρ ) of the density only when it is at least 1, in particular lies in the range from 1 to 1.2. 30. The system according to claim 1 or 2, in which the measuring electronic unit by at least measuring signals of temperature, pressure and flow is configured to determine the measured value of the mass flow rate, in particular digital, which represents the fraction of the mass flow rate of the flowing medium in a given the moment and / or the place of measurement of the flow is located upstream in front of the place of temperature measurement and / or the place of pressure measurement. 31. The system according to claim 1 or 2, in which at least one flow sensor is formed by at least one piezoelectric and / or at least one piezoresistive element or at least one electric resistive element, made with the possibility of flowing through it at least temporarily the heating current, and / or at least one, in particular in contact with the flowing medium, made with the possibility of removal of electric potentials by a measuring electrode, or at least one reacting on treason the flow parameter is measured by a measuring capacitor, and at least one flow sensor is subject to mechanical deformation during operation under the influence of a medium flowing in the measuring system or is made with the possibility of periodic displacement relative to a static initial position under the influence of a medium flowing in the measuring tube, or at least , one flow sensor is formed of at least one placed in the technological highway, made with the possibility of at least a temporary vibration and when working with a measuring tube, as well as at least one made with the possibility of registering the vibrations of the measuring tube, in particular, an electrodynamic or optoelectronic vibration sensor, or at least one obstruction of the flow narrowing the cross section of the technological line, in particular a shutter or nozzle , as well as at least one differential pressure sensor, formed, in particular, partially installed in the place of pressure measurement pressure sensor, configured to register The pressure difference above the obstacle and the formation of the measuring signal representing it, or the measuring system contains at least one retaining body, which is immersed in the medium and located, in particular, upstream of the flow sensor in front of the flow sensor. 32. The system according to claim 1 or 2, in which the medium is in a thermodynamic state, which is at least temporarily significant, in particular in a degree significant for a given measurement accuracy of the measuring system, differs with respect to at least one local parameter thermodynamic state, in particular temperature, and / or pressure, and / or density, from the thermodynamic state of the medium in the place of temperature measurement and / or from the thermodynamic state of the medium in the place of pressure measurement, and / or the flowing medium has t Reynolds number 1000, and / or medium is compressible, in particular has a compressibility κ = -1 / V · dV / dp more than 10 ^-6 bar ^-1, and / or at least partially gaseous, in particular, such so that the medium is saturated with solid particles and / or drops of gas, and / or the medium is two or more phase, in particular, in such a way that one phase of the medium is liquid, and / or the medium is saturated with gas and / or solid particles liquid. 33. The system according to claim 1 or 2, in which the technological line, at least in certain areas, in particular in the area of at least the place of density measurement and / or in the area of at least the place of pressure measurement, is made in the form of a basically form-stable under working pressure, in particular a severe and / or circular in cross-section, a pipeline, and / or a process line, at least in separate sections, in particular in the area between the density and pressure measuring points and / or between the places density and temperature measurements , made in the form of a basically direct, in particular circular in cross-section, pipeline, and / or wherein the process line has a gauge (D1) in the virtual place of density measurement that differs from its caliber (D2) at the place of pressure measurement, in particular, thus that the caliber (D2) of the technological line at the place of pressure measurement is greater than its caliber (D1) at the virtual place of density measurement and / or the ratio of the caliber (D2) of the technological line at the place of pressure measurement to its caliber (D1) in the virtual place of density measurement by is kept greater than 1.1, and / or the ratio of the gauge (D2) of the technological line at the pressure measuring point to its gauge (D1) at the virtual density measuring point is maintained less than 5, and / or the ratio of the caliber (D2) of the technological line at the place of pressure measurement to its caliber (D1) in the virtual density measurement site is maintained in the range from 1.2 to 3.1, and / or the process line has a caliber (D1) in the virtual density measurement site, basically equal to its caliber (D2) at the pressure measurement site , and the technological master it has a section between the virtual density measurement site and the pressure measurement site, which is made, in particular, in the form of a funnel-shaped diffuser with an internal channel expanding, in particular continuously in the direction of flow, and / or the process line has a virtual density measurement site and the measurement place pressure section, which is made in the form, in particular, of a funnel-shaped nozzle with a tapering, in particular, continuously in the direction of flow of the inner channel. 34. The system according to claim 1 or 2, in which the process line has a caliber (D1) in a virtual place for measuring density, different from its caliber (D3) at the place of temperature measurement. 35. The system according to clause 34, in which the caliber (D3) of the technological line at the temperature measurement site is greater than its caliber (D1) in the virtual place of density measurement, and / or the ratio of the caliber (D3) of the technological line at the place of temperature measurement to its caliber ( D1) in the virtual place of density measurement is supported by more than 1.1, and / or the ratio of the caliber (D3) of the technological line at the place of measurement of temperature to its caliber (D1) in the virtual place of measurement of density is supported less than 5, and / or the ratio of caliber (D3) technology highway in place of the temperature measurement to its caliber (D1) in the virtual location measurement of density is maintained in the range from 1.2 to 3.1. 36. The system of claim 34, wherein the process line has a section between the virtual density measurement site and the temperature measurement site, which is made in the form of, in particular, a funnel-shaped diffuser with an internal channel expanding, in particular continuously in the direction of flow. 37. The system of claim 34, wherein the process line has a section between the virtual density measurement site and the temperature measurement site, which is made in the form of, in particular, a funnel-shaped nozzle with a narrowing channel, in particular, continuously flowing in the direction of flow. 38. The system according to claim 1 or 2, in which the technological line has a caliber (D1) in the virtual place of density measurement, basically equal to its caliber (D3) at the place of temperature measurement. 39. The system according to claim 1 or 2, in which the virtual density measurement location is located upstream in front of the temperature measurement location and / or pressure measurement location, and / or the pressure measurement location is located downstream of the temperature measurement location, and / or distance (L ₂₁₎ of the density measuring pressure measurement position to the virtual space differs from the distance (L ₃₁₎ of measuring the temperature of the measurement site to a virtual space density, and / or the distance (L ₂₁₎ from the pressure measurement position to the virtual measuring point is tighter STI greater than the distance (L ₃₁₎ of the density measurement temperature measurement space to a virtual space, and / or the distance (L ₂₁₎ of the density measuring pressure measurement space to a virtual space larger gauge (D2) the process line at the point of pressure measurement, and / or the distance (L ₂₃ ) from the place of pressure measurement to the place of temperature measurement is larger than the caliber (D2) of the process line at the place of pressure measurement, in particular, so that the distance (L ₂₁ ) from the place of pressure measurement to the virtual place of density measurement with corresponds to at least 3-fold, in particular more than 5-fold, the caliber (D2) of the process line at the pressure measurement site, and / or wherein the distance (L ₂₃ ) from the pressure measurement point to the temperature measurement point corresponds to at least 3 times, in particular more than 5 times, the caliber (D2) of the process line at the pressure measurement site. 40. The system according to claim 1 or 2, in which the measuring electronic unit through, in particular, a serial field bus and / or wirelessly via radio is connected to a temperature sensor, and / or the measuring electronic unit through, in particular, a serial field bus and / or wirelessly connected by radio to a pressure sensor, and / or the measuring electronic unit comprises a microcomputer, which serves, in particular, to generate at least a measured density value (X _ρ ). 41. The system according to claim 1 or 2, containing at least one, in particular, explosion-proof, and / or resistant to pressure, and / or shockproof, and / or weather-resistant, and / or metal, and / or mounted on a technological line, and / or a housing installed in the immediate vicinity of the virtual density measurement site, in which at least partially a measuring electronic unit is located, and / or containing an indicator for visual display at least temporarily connected to the measuring electronic unit, at least from measured value of density. 42. The system according to claim 1 or 2, in which the correction value (X _K ) of the density corresponds to, in particular, the particular medium being measured and the installation position at the moment and / or the local variability at the moment arising along the flow axis of the measurement system, at least one local parameter of the thermodynamic state of the medium and / or due to the design of the measuring system, and / or local changeability at the given moment of the Reynolds number fluid medium and / or measuring electronic unit is configured to at least temporarily determine a preliminary measured value (

) density based on the rule:

where n is the molar mass, z is the real gas coefficient of the medium calculated according to one of the industrial standards AGA 8, AGA NX-19, SGERG-88 IAWPS-IF97, ISO 12213: 2006 and / or by means of a measuring signal of temperature and / or pressure, a R _M is the relative gas constant of the medium being measured, which corresponds to the absolute gas constant R / n normalized by the molar mass n of the medium at R = 8.3143 J / (K mol), and / or the measuring electronic unit is configured to at least temporarily determining the preliminary measured value (

) density based on the rule:

where π _IAWPS-IF97 = X _p / P * _IAWPS-IF97 and γ _IAWPS-IF97 = g _IAWPS-IF97 / (R _M * X _ϑ ), P * is the medium-specific critical pressure according to the industry standard IAWPS-IF97, in particular 16.53 MPa, if the medium being measured is water above which this medium cannot in any case be liquid, ag _IAWPS-IF97 is _medium -specific free enthalpy (Gibbs free energy) according to the industry standard IAWPS-IF97, and / or the measuring electronic unit is arranged to determine the measured value (X _ρ) by using both density was measured prior nnogo values (

) density, and the correction value (X _K ) of the density, in particular based on the rule:

and / or a measuring electronic unit, by means of at least a measured density value and a measured volumetric flow rate value, is configured to determine a measured mass flow rate value (X _m ), in particular a digital one, which represents the fraction of the mass flow rate of the flowing medium at a given moment. 43. The system according to claim 1 or 2, in which the measuring electronic unit contains, in particular, a non-volatile data memory in which at least one parameter specifying a particular medium to be measured is stored temporarily (SP _M ) of the first kind system, in particular the specific heat of the medium particularly, molar mass and / or the number of degrees of freedom of the medium, and at least one specifying specifically measured by the system environment and the loading position of the system at the moment parameter (SP _ME) of the second type system, and the installation position is also determined by the location of the pressure, temperature and density measurement points with respect to each other, as well as by the shape and size of the process line in the area of the place of measuring pressure, density and / or temperature, and the measuring electronic unit is configured to determine the measured value (X _ρ ) of the density by at least a parameter (SP _M ) of the first kind and a parameter (SP _ME ) of the second kind of system, and / or the measuring electronic unit is made with the possibility of at least temporary reception, in particular, calculated outside the measuring system and / or close in time of the numerical parametric values of at least one parameter that specifies the medium to be measured and / or the current installation position of the system (SP _M , SP _ME ), in particular c _p the specific heat of the medium, which is pre-calculated and / or measured at a distance from the measuring point density specific heat of the medium c _p, and / or the measuring electronic unit is adapted to POSSIBILITY determining during operation, at least at times, specific heat c _p specifically the medium, in particular, on the basis of rules:

where n is the molar mass, R is the absolute gas constant with R = 8.3143 J / (K mol), af is the number of vibrational degrees of freedom of its atoms or molecules determined by the molecular structure of the medium. 44. The use of the measuring system according to any one of claims 1 to 43 for recording and outputting density, as well as at least one measured parameter, in particular mass flow rate, volumetric flow rate, flow rate, viscosity, pressure, temperature flowing through the process lines of the medium, in particular hydrogen, nitrogen, chlorine, oxygen, helium or the compounds and / or mixtures formed by them, in particular carbon dioxide, water, phosgene, natural gas or air.

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