Procedure for a measuring instrument and measuring instrument

Abstract

A method for automatically selecting a mapping function (AF) from a set (MAF) of at least two predefined mapping functions for a measuring instrument, wherein the measuring instrument is configured to acquire a measured value of a process measurement of a medium (ME), wherein the mapping function (AF) describes a functional relationship between at least one auxiliary measurement (HG) and a measurement derived from the process measurement; wherein the method comprises at least the following steps: determining at least one first measured value (ME1) of a first decision measurement (E1); determining at least one first measured value (ME2) of a second decision measurement (E2); determining a relationship (B) between the measured values ​​(ME1, ME2) of the decision measurements (E1, E2); selecting a mapping function (AF) depending on the relationship (B).

Description

[0001] This invention relates to a method for automatically selecting an imaging function for a measuring instrument, a method for creating a set of imaging functions for a measuring instrument, and a measuring instrument that applies the methods.

[0002] In automation technology, particularly in process automation, field devices are frequently used to detect and / or control process variables. Sensors, such as those integrated into level gauges, flow meters, pressure and temperature gauges, pH / ORP meters, conductivity meters, etc., are used to detect process variables, measuring levels, flow rates, pressure, temperature, pH, ORP, and conductivity. Actuators, such as valves or pumps, are used to control process variables, changing the flow rate of a liquid in a pipe section or the fill level in a container. In principle, field devices are all those devices used close to the process that provide or process process-relevant information.

[0003] In the context of the invention, field devices also include remote I / Os, radio adapters, and electronic components in general that are arranged at the field level. A large number of such field devices are manufactured and distributed by Endress+Hauser.

[0004] Determining the dielectric constant (also known as the relative permittivity or simply permittivity) of a medium is of great interest for solids, liquids (such as fuels), and mixtures of liquids and solids (such as wastewater, chemicals, or foodstuffs), as this value can provide a reliable indicator of impurities and / or quality. According to current technology, the capacitive measurement principle can be used to determine the dielectric constant of liquid media. This principle utilizes the effect that the capacitance of a capacitor changes proportionally with the dielectric constant of the medium between the two electrodes of the capacitor.

[0005] Another method for determining the dielectric constant of a medium is a sensor array designed to interact with the medium using electromagnetic waves. German patent DE102019131504A1 describes, among other things, the measurement of dielectric constant to determine the solids content. In this method, electromagnetic signals in the form of signal sequences of varying frequencies (in the gigahertz range) are transmitted via an antenna array into a medium located in a measuring tube and then received. Based on the transit time and attenuation of the signal sequences, medium properties such as the solids content can be determined.

[0006] The measurement of the dielectric constant of a medium can be distorted if there is a (possibly small) admixture of another substance, possibly in a different state of matter than the medium. For example, air inclusions in granular materials, moisture content in granular or powdered materials, air bubbles, or suspended particles in a liquid medium can lead to changes in the measured dielectric constant that are difficult to predict. In these cases, according to the state of the art, an average dielectric constant of the mixture is determined and mapped to a known measurement value of the desired quantity, which is determined, for example, by a reference measuring instrument independently of the dielectric constant measurement.In this process, a mapping function (or transfer function) is formed, which makes it possible to map a dielectric value determined by a measuring instrument to a corrected measured value of a specific measured quantity.

[0007] Determining a measured value of a process parameter in a process with a mixed process medium containing variable proportions by mapping a permittivity measurement has the disadvantage that the mapping function used to map a mean value to the process parameter is generally dependent on the variable proportions of the process medium. For processes with a process medium containing variable proportions, the mapping function must therefore be manually adjusted for every variation in the process medium. The challenge lies in simplifying or even eliminating this necessary manual adjustment of the mapping function to the process medium.

[0008] The invention solves the problem with a method according to claim 1, with a method according to claim 9, and a measuring device according to claim 12.

[0009] The inventive method for automatically selecting a mapping function from a set of at least two predefined mapping functions for a measuring instrument, wherein the measuring instrument is configured to acquire a measured value of a process measurement of a medium, wherein the mapping function describes a functional relationship between at least one auxiliary measurement and a measurement derived from the process measurement; wherein the method comprises at least the following steps: determining at least one first measured value of a first decision measurement; determining at least one first measured value of a second decision measurement; determining a relationship between the measured values ​​of the decision measurements; selecting a mapping function depending on the relationship.

[0010] The invention has the advantage that a measuring device applying the method according to the invention can automatically determine and select a mapping function for mapping a measured value of a process quantity to a reference measured value of a reference quantity. A measuring device configured to apply the method according to the invention acquires measured values ​​of a quantity, with the mapping function being automatically selected, wherein the measured values ​​mapped by the automatically set mapping function correspond (within tolerances) to measured values ​​that a reference measuring device would display when acquiring the same quantity.

[0011] Here, the mapping function, which can also be called transfer function or system function, describes a mathematical relationship between an input and an output signal of a measuring device, and in particular maps a measured value, a measured quantity, a decision measured quantity, or similar, acquired by the measuring device to a reference measured value of a reference measured quantity.

[0012] In a further development of the method according to the invention, at least one first decision measurement variable is a specific measurement variable; wherein at least one first auxiliary measurement variable is the specific measurement variable.

[0013] The advantage of this further development is that the decision parameters and the auxiliary parameters are derived from the same set of parameters, and in particular, comprise the same parameters. In one embodiment of the invention, the first decision parameter corresponds exactly to the first auxiliary parameter, and the second decision parameter corresponds exactly to the second auxiliary parameter.

[0014] In a further embodiment of the method, a mapping function from the set of at least two predefined mapping functions comprises a relationship between auxiliary measurements and at least one measurement of the first auxiliary measurement. The advantage of this embodiment is that each mapping function from the set of at least two predefined mapping functions can be assigned to a relationship between the measurement values ​​of the auxiliary measurements, whereby a given relationship between the auxiliary measurements allows for the unambiguous assignment of a mapping function. In this context, different media can exhibit the same relationship between the auxiliary measurements and the same assigned mapping function.

[0015] In a further refinement of the procedure, the procedure continues to include the following steps: Determining a decision metric relationship between the at least one first measured value of the first decision metric and the at least one second measured value of the second decision metric; Comparing the decision metric relationship between the at least one first measured value of the first decision metric and the at least one first measured value of the second decision metric with the auxiliary metric relationship between the at least one measured value of the first auxiliary metric and the at least one measured value of the second auxiliary metric.

[0016] This design has the advantage that a relationship between the decision-making variables can be transferred to a relationship between the auxiliary variables, thus enabling the assignment of a mapping function. The comparison between the relationship of the decision-making variable and the relationship of the auxiliary variables can be mathematical in nature.

[0017] In a further embodiment of the procedure, the relationship between the decision-making parameters is a straight line; where the straight line includes a slope and an intercept.

[0018] This design has the advantage that the comparison of a relationship between auxiliary measurements parameterized by a straight line and a set of measured values ​​of decision-making variables arranged in data tuples can be easily digitized. Furthermore, the measuring device itself can determine the straight line and its parameters, for example, through linear regression.

[0019] In a further embodiment of the procedure, the relationship between the measured values ​​of the decision parameters, on the basis of which the selection of the mapping function takes place, includes the slope and / or the y-intercept.

[0020] This design has the advantage that a mathematical comparison of measured values ​​of the decision parameters arranged in data tuples with the slope and / or the y-intercept enables a determination of the mapping function to be assigned.

[0021] In a further embodiment of the procedure, determining the at least one measured value of the first decision parameter and / or the at least one measured value of the second decision parameter includes applying, in particular, various mathematical models to a measurement signal.

[0022] This design has the advantage that different mathematical models can be used to differentiate between different media using different and / or complementary components of the measurement signal.

[0023] In a further embodiment of the method, the measuring device generates a measurement signal based on a microwave signal; wherein the first decision measurement variable and the second decision measurement variable are generated based on, in particular different, parts of a permittivity spectrum of the measurement signal.

[0024] This advanced training has the advantage that a measurement signal originating from a microwave signal can encompass multiple frequency ranges, which interact differently with various media and therefore contain different information about the medium. This advantage can be utilized, for example, by employing two (or more) models, each of which bases the calculation of a measured value on at least one sub-range of the measurement signal's frequency spectrum, while that sub-range is not used, or only partially used, by the other model.

[0025] The inventive method for creating a set of mapping functions for a measuring instrument comprises a procedure that is performed for each medium from a set of at least two media, wherein the procedure comprises the following steps: acquiring several data tuples, wherein a data tuple comprises a measured value of a first auxiliary quantity of the medium acquired by the measuring instrument, a measured value of a second auxiliary quantity of the medium acquired by the measuring instrument, and a reference measured value of a reference measured quantity; determining a mapping function from the data tuples, wherein the mapping function comprises the functional relationship between the measured values ​​of the first auxiliary quantity and the reference measured values; determining a relationship between the measured values ​​of the first auxiliary quantity and the measured values ​​of the second auxiliary quantity.

[0026] The method according to the invention has the advantage that a mapping function is created for each medium of a specific selection of media using the measuring device, which mapping function makes it possible to map a measured value acquired with the measuring device to a reference measured value. Furthermore, it has the advantage that the mapping functions are assigned to a relationship between the auxiliary measured variables, whereby determining a relationship between auxiliary measured variables enables the assignment of a mapping function.

[0027] In a further development of the method according to the invention, determining the relationship between the auxiliary measured variables includes a compensation calculation.

[0028] A least squares adjustment, as defined here, is a mathematical optimization method for fitting the parameters of a given mathematical function to measured values, in this context represented by the measured values ​​of the first and second auxiliary variables contained in the data tuples. This approach has the advantage that the least squares adjustment can be executed by a program running on a microcontroller, enabling a measuring device with suitable hardware to perform this procedure itself. A further advantage is that the relationship between the auxiliary variables can be expressed in terms of the function's parameters.

[0029] In a further embodiment of the method, the relationship between auxiliary measurements includes a regression line with a slope and an intercept. The advantage of this embodiment is that a regression line is the simplest form of function that can be determined by least squares calculations, and that it has only two fundamental parameters. (Additional parameters of the regression line can include uncertainties in the fundamental parameters and / or the accuracy of a mathematical method.)

[0030] The measuring device according to the invention for detecting a measured quantity of a medium, configured for automatically selecting a mapping function based on a detected measurement signal of the medium, comprises: A sensor configured to generate a measurement signal; A data storage device configured to contain a set of at least two predefined mapping functions for a measuring device and an auxiliary measurement relationship between the first auxiliary measurement and the second auxiliary measurement according to an embodiment of the method according to the invention for creating a set of mapping functions for a measuring device;A measuring and operating circuit, wherein the measuring and operating circuit is configured to determine a measured value of a first decision measurement variable based on the measuring signal, wherein the measuring and operating circuit is configured to determine a measured value of a second decision measurement variable based on the measuring signal, wherein the measuring and operating circuit is configured to carry out an embodiment of the inventive method for automatically selecting an imaging function from a set of at least two predetermined imaging functions for a measuring device.

[0031] In a further development of the measuring device according to the invention, the measuring and operating circuit is configured to detect an imaging function and to include the detected imaging function in the data set and / or to store it in the data memory.

[0032] This further development has the advantage that the data set, which contains the set of at least two predefined mapping functions, can be generated using the measuring device according to the invention. For example, the measuring device can be used to create and save the data set for different media using the inventive method for generating a set of mapping functions for the measuring device.

[0033] The invention is further explained using the following figures. It shows: Fig. 1 an embodiment of the inventive method for the automatic selection of an imaging function; Fig. 2 an embodiment of the inventive method for creating a set of mapping functions; Fig. 3. A configuration of an imaging function; Fig. 4. A design of the relationship between decision metrics; Fig. 5 a schematic representation of an embodiment of the inventive method for the automatic selection of an imaging function; Fig. 6 an embodiment of the measuring device according to the invention.

[0034] The in Fig. Figure 1, an embodiment of the inventive method for the automatic selection of a mapping function AF, shows the first step, determining at least one first measured value ME1 of a first decision metric E1; the second step, determining at least one first measured value ME2 of a second decision metric E2; the third step, determining a relationship B between the measured values ​​ME1 and ME2 of the decision metrics E1 and E2; and the fourth step, selecting a mapping function AF depending on the relationship B. In this embodiment, the relationship B between the decision metrics E1 and E2 comprises a functional, in particular linear, decision metric relationship ZE between the decision metrics E1 and E2.The determined decision metric relationship ZE is compared with an auxiliary metric relationship ZH, where a comparison involves the mathematical comparison of parameters of a mathematical function, and each auxiliary metric relationship ZH is assigned a mapping function AF from the set MAF of mapping functions AF. In this specific example, automatic selection means determining the auxiliary metric relationship ZH that best matches the determined decision metric relationship ZE, and selecting the mapping function AF assigned to the best-matching auxiliary metric relationship ZH.

[0035] The in Fig. Figure 2, an embodiment of the inventive method for creating a set of MAF mapping functions AF for a number of different media ME, ME', ME'', comprises a first step, acquiring several data tuples DT, with measured values ​​MH1, MH2 of the auxiliary measured quantities H1, H2 and the measured value MR of the reference measured quantity R; a second step, determining a mapping function AF from an auxiliary measured quantity H1, H2 to a reference measured quantity R; and a third step, determining an auxiliary measured quantity relationship ZH between the measured values ​​MH1, MH2 of the auxiliary measured quantities H1, H2. In this embodiment, a mapping function AF and a uniquely assigned auxiliary measured quantity relationship ZH are created for each medium, both of which are stored, for example, in a data set.In this context, subsets of the different media ME, ME', ME'' can have the same mapping function AF if they have the same auxiliary measurement relationship ZH (within tolerances).

[0036] The in Fig. Figure 3, illustrating a mapping function AF, shows a coordinate system with a first axis, on which measured values ​​ME1 of the first decision variable E1 are plotted, and a second axis, on which the reference measured values ​​MR are plotted. Also shown as points are tuples (ME1, MR), each containing a measured value ME1 of the first decision variable E1 and a reference measured value MR. In this configuration, the measured values ​​ME1 and MR were acquired within a predetermined time interval and are thus correlated. A tuple (ME1, MR) represents a mapping of a measured value ME1 of the decision variable to a reference measured value MR of the reference variable R. From the set of tuples (ME1, MR), a functional relationship between the measured values ​​ME1 and MR can be determined using a mathematical procedure, such as least squares.In this example, the relationship is linear and can be parameterized by a regression line G with a y-intercept GA and a slope GS. The regression line G is therefore a mathematical parameterization of the mapping function AF from the first decision variable E1 to the reference variable R. The complete description of the... Fig. 3 can be transferred to the first auxiliary measurement quantity H1 and the associated measurement values ​​MH1, where EH1 is replaced by MH1 and E1 by H1.

[0037] The in Fig. Figure 4, illustrating the relationship between decision parameters E1 and E2, shows a coordinate system with a first axis and a second axis. The first axis plots measured values ​​ME1 of the first decision parameter E1, and the second axis plots measured values ​​ME2 of the second decision parameter E2. The tuples (ME1, ME2) are represented as points in the coordinate system, each containing one measured value ME1 of the first decision parameter E1 and one measured value ME2 of the second decision parameter E2 for a medium ME. In this illustration, the measured values ​​ME1 and ME2 of a tuple are generated by different models using the same measurement signal MS (not shown here).From the set of tuples (ME1, ME2), a functional relationship between the measured values ​​ME1, ME2 can be determined using a mathematical procedure, such as least squares. In this example, the relationship is linear and allows for a mathematical parameterization of the decision metric relationship ZE. The figure contains further tuples (ME1', ME2') which comprise measured values ​​ME1', ME2' acquired in a different medium ME'. Based on these additional tuples (ME1', ME2'), another decision metric relationship ZE' is determined, which in this example is also linear and can be mathematically parameterized accordingly. This figure illustrates how a decision metric relationship ZE, ZE' enables a differentiation between media ME, ME'. The complete description of the... Fig. 4 can be applied to the auxiliary measured quantities H1, H2 and the associated measured values ​​MH1, MH2, where EH1 is replaced by MH1, EH2 by MH2, E1 by H1, and E2 by H2.

[0038] The in Fig. Figure 5, a schematic representation of the inventive method for the automatic selection of a mapping function, shows how, based on a captured decision measurement variable E1, two, in particular different, measured values ​​ME11 and ME22 are determined using a model 1 and a model 2. These measured values ​​exhibit a decision measurement variable relationship ZE1, which is automatically determined, for example, by a measuring and operating circuit of a measuring device. Based on the determined decision measurement variable relationship ZE1, a mapping function AF1 associated with the decision measurement variable relationship ZE1 is automatically selected from a set of mapping functions MAF with at least two predefined mapping functions AF for a measuring device. Using the mapping function AF1, the measuring device can map one, in particular any, of the measured values ​​ME11 and ME12 to a reference measurement value MR1. Similarly, for a second decision metric E2, the measured values ​​ME21, ME22 are determined using Model 1 and Model 2, whereby a decision metric relationship ZE2 is determined based on the measured values ​​ME21, ME22, whereby an associated mapping function AF2 is determined based on the decision metric relationship ZE2 using the set of mapping functions MAF with at least two predefined mapping functions AF for a measuring device, whereby one of the measured values ​​ME21, ME22 is mapped to a reference measurement MR2 based on the mapping function AF2.

[0039] Fig. Figure 5 further shows an exemplary embodiment of the set of mapping functions MAF for a measuring device, which is presented here as a table, wherein the first row comprises the decision-measurement relationships ZE1, ZE2, and wherein the second row comprises the associated mapping functions AF1, AF2. According to the method of the invention, for example, a measuring and operating circuit can access this table and, after determining a decision-measurement relationship ZE1, ZE1, ZE2, select the associated mapping function AF1, AF2 from the table. In this example, the measuring and operating circuit identifies the determined decision-measurement relationship ZE1, ZE2 and identifies it with one of the entries in the first row. The associated mapping function AF1, AF2 is then determined as the mapping function AF1, AF2 which is in the same column as the determined decision-measurement relationship ZE1, ZE2.

[0040] The in Fig.Figure 6, an embodiment of the measuring device according to the invention, shows the medium ME guided in the measuring tube MR, and the sensor MA arranged in the measuring tube MR, which is configured to generate a measurement signal MS (not shown here) and transmit it to the measuring and operating circuit MB. The measuring and operating circuit MB is configured to determine a first measured value (ME1) of a first decision-making variable E1 and a second measured value (ME2) of a second decision-making variable E2 based on the measurement signal MS. Based on the measured values ​​ME1, ME2, and based on the set MAF of at least two predefined mapping functions AF for a measuring device and an auxiliary measurement variable relationship ZH contained in a data storage device DS connected to the measuring and operating circuit MB, the measuring and operating circuit MB performs a method according to the invention for automatically selecting a mapping function AF and selects a mapping function.Specifically, this means that the measuring device uses the measured values ​​ME1 and ME2 to determine which mapping function AF from the data memory DS should be used to map the decision measured values ​​ME1 to reference measured values ​​MR. This version of the measuring device also features an input-output module IO, which allows information to be transmitted to the measurement and operating circuit MB, for example, by a user. This transmission enables, for instance, the input of a reference measured value MR of a reference measured quantity R, making it possible to store data tuples comprising measured values ​​ME1, ME2, and reference measured values ​​MR in the data memory DS. Based on these data tuples, the measurement and operating circuit MB can then determine a mapping function AF and incorporate it into a data record and / or store it in the data memory DS. Reference symbol list AF, AF1, AF2 Image function MAF: Set of at least two predefined mapping functions ME Medium HG auxiliary measurement E1 first decision metric E2 second decision metric ME1, ME11, ME12 Measured value of the first decision measure ME2, ME21, ME22 Measured value of the second decision metric B relationship H1 first auxiliary measurement H2 second auxiliary measurement MH1 Measured value of the first auxiliary measurement MH2 measured value of the second auxiliary measurement ZH Auxiliary Measurement Variable Relationship ZE, ZE1, ZE2 Decision Metrics Relationship G Straight GS incline GA axis section MS measurement signal MME quantity of at least two media DT data tuples R Reference measurement MR, MR1, MR2 Reference measurement MA sensor DS Data Storage MB measuring and operating circuit QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 102019131504A1

[0005]

Claims

[1] Method for automatically selecting a mapping function (MF) from a set (MMF) of at least two predefined mapping functions for a measuring instrument, wherein the measuring instrument is configured to acquire a measured value of a process measurement of a medium (M), wherein the mapping function (MF) describes a functional relationship between at least one auxiliary measurement (AM) and a measurement derived from the process measurement; wherein the method comprises at least the following steps: - Determining at least one first measured value (ME1) of a first decision metric (E1); - Determining at least one first measured value (ME2) of a second decision metric (E2); - Determining a relationship (B) between the measured values ​​(ME1, ME2) of the decision metrics (E1, E2); - Selecting a mapping function (AF) depending on the relationship (B). [2] Method according to claim 1, - where at least one first decision metric (E1) is a specific metric; - where at least one first auxiliary quantity (H1) is the determined quantity. [3] Method according to one of claims 1 or 2, - wherein a mapping function (AF) from the set (MAF) of at least two given mapping functions includes an auxiliary measurement relationship (ZH) between at least one measurement (MH1) of the first auxiliary measurement (H1) and at least one measurement (MH2) of a second auxiliary measurement (H2). [4] The method of claim 3, further comprising the following steps: - Determining a decision metric relationship (ZE) of at least one first measured value (ME1) of the first decision metric (E1) and at least one second measured value (ME2) of the second decision metric (E2); - Comparing the decision measure relationship (ZE) of the at least one first measurement (ME1) of the first decision variable (E1) and the at least one first measurement (ME2) of the second decision variable (E2) with the auxiliary measure relationship (ZH) between the at least one measurement (MH1) of the first auxiliary measure (H1) and the at least one measurement (MH2) of the second auxiliary measure (H2). [5] Method according to any one of claims 1 to 4, - where the decision measure relationship (ZE) is a straight line (G); - where the straight line (G) includes a slope (GS) and an y-intercept (GA). [6] Method according to claim 5, - where the relationship of the measured values ​​(ME1, ME2) of the decision variables (E1, E2) on the basis of which the selection of the mapping function (AF) takes place includes the slope (GS) and / or the y-intercept (GA). [7] Method according to any one of claims 1 to 6, - wherein determining the at least one measured value (ME1) of the first decision measure (E1) and / or the at least one measured value (ME2) of the second decision measure (E2) involves applying, in particular, different mathematical models to a measurement signal (MS). [8] Method according to any one of claims 1 to 7, - wherein the measuring device generates a measurement signal (MS) based on a microwave signal; - wherein the first decision measure (E1) and the second decision measure (E2) are generated from, in particular different, parts of a permittivity spectrum of the measurement signal (MS). [9] Method for creating a set (MAF) of mapping functions for a measuring instrument, comprising a procedure that is performed for each medium (ME) from a set of at least two media (MME), the procedure comprising the following steps: - Capturing multiple data tuples (DT), ◯ Where a data tuple (DT) comprises a measured value (MH1) of a first auxiliary quantity (H1) of the medium (ME) acquired by the measuring instrument, a measured value (MH2) of a second auxiliary quantity (H2) of the medium (ME) acquired by the measuring instrument and a reference measured value (MR) of a reference quantity (R); - Determining a mapping function based on the data tuples (DT), ◯ where the mapping function (DT) includes the functional relationship between the measured values ​​(MH1) of the first auxiliary quantity (H1) and the reference measured values ​​(MR) of a reference quantity (R); - Determining a relationship (ZH) between the measured values ​​(MH1) of the first auxiliary quantity (H1) and the measured values ​​(MH2) of the second auxiliary quantity (H2). [10] Method according to claim 9, - where determining the auxiliary measurement relationship (ZH) includes a reconciliation calculation. [11] Method according to one of claims 9 or 10, - where the auxiliary measurement relationship (APR) includes a regression line with a slope and an y-intercept. [12] Measuring instrument for detecting a measured quantity of a medium (ME), configured for automatically selecting an imaging function (AF) based on a detected measurement signal (MS) of the medium (ME), comprising: - A measuring sensor (MA) configured to generate a measurement signal (MS); - A data storage device (DS), ◯ designed to include a set (MAF) of at least two predefined mapping functions for a measuring instrument and an auxiliary measurement relationship (ZH) between the first auxiliary measurement (H1) and the second auxiliary measurement (H2) according to one of claims 9 to 12; - A measuring and operating circuit (MB), ◯ wherein the measuring and operating circuit is configured to determine a measured value (ME1) of a first decision measurement variable (E1) based on the measuring signal (MS), ◯ wherein the measuring and operating circuit (MB) is configured to determine a measured value (ME2) of a second decision measurement variable (E2) based on the measuring signal (MS), ◯ wherein the measuring and operating circuit (MB) is configured to carry out a method according to any one of claims 1 to 8. [13] Measuring device according to claim 10, - wherein the measuring and operating circuit is configured to detect an imaging function and to include the detected imaging function in the data set and / or to store it in the data storage.

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