METHOD AND COMPUTER PROGRAM PRODUCT FOR DETERMINING THE MEASUREMENT UNCERTAINTY OF A MEASURING SYSTEM

Description

Technical area

[0001] The invention relates to a method and a computer program product for determining the measurement uncertainty of a measurement system according to the preamble of the independent claim. State of the art

[0002] As is well known, a physical quantity is measured using a measuring system. This physical quantity can be a force, a weight, a temperature, etc. The physical quantity is represented as a measured value, expressed as a number and a unit. The unit is usually standardized in Newtons (N), kilograms (kg), Kelvin (K), etc.

[0003] Generally, several steps, separated in time and space, are necessary to acquire a physical quantity. For example, if a temperature is measured in a measuring chamber, a sensor located in the chamber detects an electrical resistance as an electrical voltage. This voltage is transmitted via a signal cable as a measurement signal to an evaluation unit located remotely from the measuring chamber. There, the measurement signal is amplified and displayed as a measured value. The temperature measurement occurs before the display of the measured value. Such a measuring system therefore has several transmission elements, such as a sensor, a measuring cable, and an evaluation unit, which together form a measurement chain. Directly adjacent transmission elements in the measurement chain are related to each other in a cause-and-effect relationship for acquiring the physical quantity.

[0004] The measurement of a physical quantity is subject to measurement uncertainty, as the measured value always deviates from the true value. Therefore, ISO / IEC Guide 98-3:2008-09 requires that the physical quantity be represented as a best estimate with an associated coverage interval. The best estimate is an arithmetic mean of several measured values. The measurement uncertainty is the difference between an upper and lower limit of the coverage interval and the best estimate. The true value lies within the coverage interval with a predefined probability of being found.

[0005] Measurement uncertainty is a function of the influencing factors of the transfer elements. Each influencing factor is represented as an influencing value. A best influencing value is an arithmetic mean of several influencing factors. To determine the measurement uncertainty, a model-based approach is used according to ISO / IEC Guide 98-3:2008-09. First, the influencing factors of the transfer elements are identified, and then, for each identified influencing factor, a best influencing value and a measurement uncertainty contribution associated with the best influencing value are calculated.

[0006] It is generally desirable for users of a measuring system to know the measurement uncertainty with which a physical quantity is measured by the system. For example, the measuring system is part of a production plant for industrial goods. It frequently happens that the production plant is oversized solely due to an unknown measurement uncertainty, or that an unknown measurement uncertainty leads to defective parts during the production of the industrial goods. In both cases, the unknown measurement uncertainty results in additional costs for investment and production.

[0007] To determine the measurement uncertainty of a measurement system, a model-based approach is necessary, involving the identification of the relevant influencing factors of the transfer elements and the calculation of the best influencing values ​​and the associated measurement uncertainties. Users of measurement systems often shy away from the time and resources required for such a model-based approach. A method for fitting a model to determine measurement uncertainties is known from US 2008 / 125982.

[0008] The object of the present invention is to provide a method for determining the measurement uncertainty of a measuring system, which method requires little time and material expenditure. Description of the invention

[0009] This problem is solved by the features of an independent claim.

[0010] The invention relates to a method for determining the measurement uncertainty of a measuring system; which measuring system detects a physical quantity; which measuring system has several transmission elements; which transmission elements form a measurement chain for detecting the physical quantity, wherein directly adjacent transmission elements in the measurement chain are in a cause-and-effect relationship to each other; comprising the steps: a) reading information for identifying the transmission elements of the measurement chain by a computer program; b) reading readable labels of influencing factors of the identified transmission elements by the computer program, and determining the relevance of the influencing factors of the identified transmission elements to the measurement uncertainty of the measuring system by the computer program;and c) use of influencing factors identified as relevant for calculating the measurement uncertainty of the measurement system by the computer program product.;

[0011] The patent applicant has determined that, as a commercial provider of measurement systems, she possesses sufficient expertise to assist a user of an existing measurement system in determining its measurement uncertainty. This is because users often assemble their measurement chains from existing transmission elements, selecting them based on their ease of availability. However, the user is unaware of the measurement uncertainty of the system.

[0012] This is where the invention comes into play. In the method according to the invention, the user is provided with the applicant's expert knowledge. The transmission elements of the measurement chain assembled by the user are identified, and the influencing factors of the identified transmission elements on the measurement uncertainty of the measurement system are determined. The measurement uncertainty of the measurement system is then calculated using these determined influencing factors.

[0013] Preferably, for each identified influencing factor, a measurement uncertainty contribution is provided, corresponding to a best estimate of the identified influencing factor. The measurement uncertainty of the measuring system is calculated from the provided measurement uncertainty contributions. For the user, the inventive method involves minimal time and material expenditure.

[0014] Steps a) to c) in the inventive process for determining the measurement uncertainty of a measuring system are carried out by a computer program product. Brief description of the drawings

[0015] The invention will now be explained in more detail using the figures as an example. They show Fig. 1 shows a representation of a measuring system with several transfer elements; Fig. 2 shows a diagram of the steps in the procedure for determining the measurement uncertainty of the measuring system according to Fig. 1 Fig. 3 shows a representation of a computing system for a computer program product for carrying out the method according to Fig. 2 Fig. 4 shows a representation of a first embodiment of the computing system according to Fig. 3 to carry out step a) of the procedure according Fig. 2 Fig. 5 shows a representation of a second embodiment of the computing system according to Fig. 3 to carry out step a) of the procedure according Fig. 2Fig. 6 A representation of a first embodiment of a method according to step c) Fig. 2 calculated measurement uncertainty from measurement uncertainty contributions; Fig. 7 A representation of a second embodiment of a procedure according to step c) Fig. 2 calculated measurement uncertainty from measurement uncertainty contributions; Fig. 8 a representation of the adjustment of the power of the measuring system with that in the first embodiment of the method according to Fig. 2 and 6 calculated measurement uncertainty; and Fig. 9 a representation of the adjustment of the power of the measuring system with that in the second embodiment of the method according to Fig. 2 and 7 calculated measurement uncertainty. Ways to implement the invention

[0016] Fig. 1Figure 1 shows an embodiment of a measuring system S with several transmission elements G1-G4. As explained in the introduction, the measuring system S serves to detect a physical quantity. For this purpose, the transmission elements G1-G4 form a measuring chain K. Directly adjacent transmission elements G1-G4 of the measuring chain K, for example, transmission elements G1 and G2, or transmission elements G2 and G3, are related to each other in a cause-and-effect relationship for detecting the physical quantity. In the embodiment according to Figure 1, the transmission elements G1-G4 are connected in a cause-and-effect relationship. Fig. 1 Four transfer elements G1-G4 are shown; with knowledge of the invention, the person skilled in the art can of course implement a measuring system with more or fewer transfer elements.

[0017] The transmission element G1 is a sensor, such as a pressure sensor, an accelerometer, a temperature sensor, etc. The sensor measures the physical quantity (pressure, acceleration, temperature, etc.) and generates an analog signal, such as an electrical current or voltage. For a piezoelectric sensor, the physical quantity can be measured at a frequency of up to 100 kHz. Under normal conditions, the analog signal of a piezoelectric sensor is proportional to the physical quantity. A piezoelectric sensor can measure force with a sensitivity of a few pC / N. However, this sensitivity changes with the ambient temperature and the age of the piezoelectric sensor.The analog measurement signal also exhibits a deviation from proportionality to the physical quantity being measured, which is referred to as the linearity of the piezoelectric sensor. Finally, the analog measurement signal is only reproducible with a measurement accuracy equal to that of the piezoelectric sensor. A first influencing factor E11 of the transfer element G1 relevant to the measurement uncertainty U of the measurement system S is the "temperature dependence of the measurement sensitivity of the piezoelectric sensor." A second influencing factor E12 of the transfer element G1 relevant to the measurement uncertainty U of the measurement system S is the "age-related change in the measurement sensitivity of the piezoelectric sensor." A third influencing factor E13 of the transfer element G1 relevant to the measurement uncertainty U of the measurement system S is the "linearity of the piezoelectric sensor."A fourth influencing factor E14 of the transfer element G1 that is relevant to the measurement uncertainty U of the measurement system S is the "reproducibility of the analog measurement signal".

[0018] The transmission element G2 is a signal cable that transmits the analog measurement signal from the sensor to an electrical amplifier. For piezoelectric sensors, the analog measurement signal can have a measurement frequency of up to 100 kHz and an electrical charge of a few pC. The cable impedance of the signal cable is crucial here. Especially if the signal cable is not terminated with a characteristic impedance, the cable impedance changes at the input. A first influencing factor E21 of the transmission element G2, relevant to the measurement uncertainty U of the measurement system S, is the "length of the signal cable". A second influencing factor E22 of the transmission element G2, relevant to the measurement uncertainty U of the measurement system S, is the "transmission frequency".

[0019] The transfer element G3 is the electrical amplifier, which receives the transmitted analog measurement signal, amplifies it electrically, and converts it into a digital measurement signal. A first influencing factor E31 of the transfer element G3 relevant to the measurement uncertainty U of the measurement system S is the "measurement accuracy of the electrical amplifier." A second influencing factor E32 of the transfer element G3 relevant to the measurement uncertainty U of the measurement system S is the "crosstalk between input channels of the electrical amplifier."

[0020] The transmission element G4 is an evaluation unit that evaluates the digital measurement signal. The evaluation unit comprises a data processing processor, a data storage unit, and a display. For evaluation, the digital measurement signal can be loaded into a computer program running on the data processing processor. The computer program can then further process the digital measurement signal. The digital measurement signal can be stored in the data storage unit. It can also be displayed on the display. A first influencing factor E41 of the transmission element G4, relevant to the measurement uncertainty U of the measurement system S, is a "rounding error during further processing." A second influencing factor E42 of the transmission element G4, relevant to the measurement uncertainty U of the measurement system S, is a "speed of further processing."

[0021] With knowledge of the present invention, the person skilled in the art can implement a measuring system with other transmission elements and other relevant influencing variables.

[0022] Fig. 2This is a scheme of steps a) to e) in method V for determining the measurement uncertainty U of the measuring system S. Steps a) to c) are essential to the invention. The further steps d) and e) are optional. In step a), the transfer elements G1-G4 of the measuring chain K are identified. In step b), the influences E11-E42 of the identified transfer elements G1-G4 on the measurement uncertainty U of the measuring system S are determined. In step c), the determined influences E11-E42 are used to calculate the measurement uncertainty U of the measuring system S. In step d), at least one identified transfer element G1-G4 with a measurement uncertainty contribution U11-U44 that deviates from an average measurement uncertainty contribution UØ is determined. And in step e) at least one substitute transfer element G1*-G4* with substitute measurement uncertainty contribution U11*-U44* is determined for the at least one specific transfer element G1-G4.

[0023] Fig. 3Figure 1 shows a computing system R for a computer program product C for carrying out the procedure V to determine the measurement uncertainty U of the measuring system S. The computing system R comprises a data processing processor R1, a data storage device R2, at least one input unit R3, R3', an output unit R4, and at least one communication unit R5, R5'. The computing system R can be a commercially available computer. The input unit R3, R3' can be a computer keyboard, a computer mouse, a touchscreen, a data interface, etc. The output unit R4 can be a computer monitor, a touchscreen, etc. The communication unit R5, R5' communicates data between the components of the computing system R. The communication unit R5, R5' can be a network such as the Internet, a computer bus such as the Peripheral Component Interconnect Express (PCIe) bus, etc.The data interface is connected to the communication unit R5, R5' in the embodiment of a network, it can communicate in the network according to a network protocol such as the Internet Protocol (IP), the PCIe protocol, and it can be accessed in the network via a network address.

[0024] Individual components of the computing system R can be located at the user's measuring system S, or they can be located remotely from the user's measuring system S. For the purposes of this invention, "remotely" means any distance whatsoever. The components of the computing system R can also be located arbitrarily far apart from one another. For example, only the input unit R3 and the output unit R4 can be located at the user's location, while the data processing processor R1 and the data storage unit R2 are located remotely from the user. Furthermore, the components of the computing system R can be present multiple times. For instance, a first input unit R3 and a first output unit R4 can be located at the user's location, while a second input unit R3' is located remotely from the user. It is also possible for the computing system R to have a first communication unit R5 and a second communication unit R5'.

[0025] The computer program product C can be stored in the data memory R2 and loaded from the data memory R2 into the data processing processor R1 and can be executed in the data processing processor R1 to carry out the procedure V for determining the measurement uncertainty U of the measuring system S.

[0026] To execute step a), digital information data I for identifying the transmission elements G1-G4 is read into the computer program product C. The digital information data I is read from the data storage R2 via the input unit R3 and the communication unit R5.

[0027] In the first embodiment of step a) after Fig. 4The user can enter information for identifying the transmission elements G1-G4 of the measuring chain K via the input unit R3 in the form of a computer keyboard, or the user can enter information for identifying the transmission elements G1-G4 of the measuring chain K on the input unit R3 in the form of a touchscreen by selecting transmission elements depicted on it. The information entered at the input unit R3 is then communicated as digital information data I via the communication unit R5 to the data processing processor R1 and read there by the computer program product C.

[0028] In the second embodiment of step a) after Fig. 5The user can input information for identifying the transmission elements G1-G4 of the measuring chain K via a first input unit R3 in the form of a computer keyboard or a computer touchscreen. The computer is in Fig. 5Not shown in the figures. The first input unit R3 is connected to the first communication unit R5 via the computer in a network configuration. The first input unit R3 calls the network address of the second input unit R3' via the computer and the first communication unit R5 in a data interface configuration. The input information from the first input unit R3 is then communicated as digital information data I to the network address of the second input unit R3'. The digital information data I communicated to the second input unit R3' is communicated via the second communication unit R5 to the data processing processor R1 and read there by the computer program C.

[0029] With further reference to Fig. 5Is it also possible that, in a third embodiment of step a), the computer program product C automatically reads digital information data for the identification of the transmission elements G1-G4 of the measuring chain K without user interaction? For this purpose, the transmission elements G1-G4 have at least one information transmitter such as a Transducer Electronic Data Sheet (TEDS) according to the standard Institute of Electrical and Electronics Engineers (IEEE) 1451. The information transmitter is in Fig. 5Not shown in figures. The information provider is a data storage device. Digital information data I from the transmission elements G1-G4 is stored in the information provider. The information provider is connected to the first communication unit R5, in the embodiment of a network, via at least one first input unit R3 in the embodiment of a data interface. The computer program product C is connected to the first communication unit R5 via the second input unit R3' in the embodiment of a data interface. The computer program product C calls the network address of the at least one first input unit R3 via the second input unit R3' and the first communication unit R5. The digital information data I is then communicated from the information provider thus called to the network address of the second input unit R3'.The digital information data I communicated to the second input unit R3' are communicated via the second communication unit R5' to the data processing processor R1 and read in there by the computer program product C.

[0030] With knowledge of the present invention, a person skilled in the art can combine the three embodiments of step a) presented above. According to the first embodiment of step a), the user can enter information for identifying the transmission elements G2-G4 via a touchless screen by selecting transmission elements depicted thereon, while according to the third embodiment of step a), the computer program product C automatically reads in digital information data of the transmission element G1.

[0031] In step b), the computer program C determines the influencing factors E11-E42 on the measurement uncertainty U of the measurement system S for the identified transfer elements G1-G4. For this purpose, the computer program C accesses the data memory R2 containing previously determined influencing factors E11-E42 of transfer elements G1-G4. A distinction is made between relevant and irrelevant influencing factors. An influencing factor is relevant if it makes a significant contribution to the measurement uncertainty U of the measurement system S. Preferably, those influencing factors are considered relevant which have the largest absolute values ​​in the measurement uncertainty U of the measurement system S and which, in total, contribute at least 80% to the measurement uncertainty U of the measurement system S. The relevance of an influencing factor is determined beforehand.Preferably, only relevant influencing factors are considered when determining the factors affecting the measurement uncertainty U of the measuring system S. Preferably, relevant influencing factors have a legible label indicating "relevant," while irrelevant influencing factors have a legible label indicating "not relevant." The computer program C can read the labels and, by recognizing the information on the labels, determine the relevance of the influencing factors to the measurement uncertainty U of the measuring system S.

[0032] The computer program product C determines at least one relevant influencing variable E11-E42 for each identified transmission element G1-G4 and loads it from the data memory R2. For the identified transmission element G1 in the embodiment of a piezoelectric sensor, the computer program product C loads the relevant influencing variables E11-E14 "temperature dependence of the measurement sensitivity of the piezoelectric sensor", "age-related change in the measurement sensitivity of the piezoelectric sensor", "linearity of the piezoelectric sensor", and "reproducibility of the analog measurement signal" from the data memory R2. For a signal cable as an identified transmission element G2, the computer program product C loads the relevant influencing variables E21, E22 "length of the signal cable", and "transmission frequency" from the data memory R2.For an electrical amplifier, identified as the transmission element G3, the computer program product C loads the relevant parameters E31 and E32, "measurement accuracy of the electrical amplifier" and "crosstalk between input channels of the electrical amplifier," from data memory R2. For an evaluation unit, identified as the transmission element G4, the computer program product C loads the relevant parameters E41 and E42, "rounding error during further processing" and "speed during further processing," from data memory R2. The relevant parameters E11-E42 loaded from data memory R2 are communicated via the communication unit R5 to the data processing processor R1 and read there by the computer program product C.

[0033] In step c), the computer program product C uses the determined influencing variables E11-E42 to calculate the measurement uncertainty U of the measuring system S. For this purpose, the data memory R2 also stores best estimates of the influences and the measurement uncertainty contributions associated with these best estimates for the previously determined influencing variables. In data memory R2, a measurement uncertainty contribution associated with the best estimate of the influence is provided for each influencing variable. For each determined influencing variable E11-E42, the computer program product C loads a measurement uncertainty contribution U11-U42 associated with the best estimate of the determined influencing variable E11-E42 from data memory R2. The measurement uncertainty contributions U11-U42 loaded from data memory R2 are communicated to the data processing processor R1 via the communication unit R5 and read there by the computer program product C.

[0034] The computer program product C displays the calculated measurement uncertainty U of the measuring system S on the output unit R4. As in the two embodiments according to Figs. 6 and 7 The ordinate represents the magnitude B of the measurement uncertainty contributions U11-U42, and the abscissa represents the number A of measurement uncertainty contributions U11-U42. The computer program C calculates the measurement uncertainty U of the measurement system S by summing the squares of the measurement uncertainty contributions U11-U42 and taking the square root of the resulting sum.

[0035] In the first embodiment according to Fig. 6 The measurement uncertainty U = 9.3 for ten measurement uncertainty contributions U11-U42.

[0036] In the second embodiment according to Fig. 7 The measurement uncertainty U = 9.1 for ten measurement uncertainty contributions U11-U42.

[0037] In step d), the computer program product C determines at least one identified transfer element G1-G4 with an extreme measurement uncertainty contribution U11-U42. For the purposes of the invention, a measurement uncertainty contribution U11-U42 is extreme if it is smaller or larger than at least one of the other measurement uncertainty contributions U11-U42.

[0038] In the first embodiment according to Fig. 6 For a calculated measurement uncertainty U of a measurement system S, seven measurement uncertainty contributions U11, U21, U22, U31, U32, U41, U42 are extreme, with the three measurement uncertainty contributions U11, U41, U42 being the smallest, and the four measurement uncertainty contributions U21, U22, U31, U32 being the largest.

[0039] In the second embodiment of a calculated measurement uncertainty U of a measuring system S according to Fig. 7Six measurement uncertainty contributions U12, U13, U14, U21, U32, U42 are extreme, with the two measurement uncertainty contributions U32, U42 being the smallest, and the four measurement uncertainty contributions U12, U13, U14, U21 being the largest.

[0040] In Figs. 8 and 9 Two examples of the measurement uncertainty U of a measuring system S are shown as a function of the power L of a measuring system S. The ordinate represents the measurement uncertainty U of the measuring system S, and the abscissa represents the power L of the measuring system S. The measurement uncertainty U of the measuring system S is a multidimensional characteristic map and depends on parameters of the power L of the measuring system S, such as performance, availability, number of maintenance cycles, maintenance quality, purchase price, environmental influences, etc. The measurement uncertainty U of the measuring system S with the transfer functions G1-G4 is represented as the point S(G1, G2, G3, G4).

[0041] By representing the measurement uncertainty U in the exemplary embodiments according to Fig. 6 to 9 The user not only becomes aware of the measurement uncertainty U of the measuring system S, but can also assess the measurement uncertainty U of the measuring system S as a function of the power L of the measuring system S.

[0042] For the example presented at the beginning, a measuring system as part of a production plant for industrial goods, where the production plant is oversized due to an unknown measurement uncertainty, it shows Fig. 6 a first embodiment of the measurement uncertainty U calculated for the measuring system S and Fig. 8A first embodiment of the calculated measurement uncertainty U as a function of the power L of the measuring system S. The user recognizes that the measurement uncertainty contributions U41, U42 for the relevant influencing variables E41, E42 "rounding error in further processing" and "speed in further processing" are smallest. This finding leads to the conclusion that the identified transfer element G4 is oversized as an evaluation unit. To save on investment costs, the computer program product C replaces the identified transfer element G4 with a substitute transfer element G4*, which has comparatively larger substitute measurement uncertainty contributions U41*, U42*.

[0043] And for the example of a measuring system as part of a production plant for industrial goods, also presented at the beginning, where the production of the industrial goods leads to defective parts due to an unknown measurement uncertainty, it shows Fig. 7 a second embodiment of the measurement uncertainty U calculated for the measuring system S and Fig. 9A second embodiment of the calculated measurement uncertainty U as a function of the power L of the measuring system S. The user recognizes that the measurement uncertainty contributions U12-U14, U21 are largest for the relevant influencing variables E12 "age-related change in the measurement sensitivity of the piezoelectric sensor", E13 "linearity of the piezoelectric sensor", E14 "reproducibility of the analog measurement signal", and E21 "length of the signal cable". This finding leads to the conclusion that the specific transfer elements G1, G2 exhibit above-average measurement uncertainty contributions U12-U14, U21. To reduce the number of defective parts and thus also the production costs, the computer program product C replaces at least one specific transmission element G1, G2 with a replacement transmission element G1*, G2*, which has a comparatively smaller replacement measurement uncertainty contribution U12*-U14*, U21*.

[0044] In step e), the computer program product C determines at least one substitute transmission element G1*-G4* with a substitute measurement uncertainty contribution U11*-U42* for the at least one specific identified transmission element G1-G4. For this purpose, digital information data I, I* of transmission elements G1-G4, G1*-G4* are stored in the data memory R2. The digital information data I, I* are essential technical characteristics of transmission elements G1-G4, G1*-G4*. These essential technical characteristics identify the transmission elements G1-G4, G1*-G4*. Preferably, the data memory R2 stores essential technical characteristics of a very large number of transmission elements G1-G4, G1*-G4*. This ensures that at least one equivalent substitute transmission element G1*-G4* is stored for a specific identified transmission element G1-G4.In accordance with the invention, a replacement transmission element G1*-G4* is equivalent if it matches the identified transmission element G1-G4 in its essential features and if it differs from the identified transmission element G1-G4 only in at least one measurement uncertainty contribution U11-U42.

[0045] Thus, the transmission element G1 of the measuring system S is a sensor, and for the embodiment of a piezoelectric sensor, the essential technical characteristics are the measuring range, the measuring sensitivity, the measuring accuracy, etc.

[0046] The transmission element G2 of the measuring system S is a signal cable. The essential technical characteristics of the signal cable are the cable impedance at the input of the signal cable, the length of the signal cable, etc.

[0047] The transfer element G3 of the measuring system S is an electrical amplifier. The essential characteristics of the electrical amplifier are its measurement accuracy, crosstalk between input channels, etc.

[0048] And the transmission element G4 of the measuring system S is an evaluation unit. The essential technical characteristics of the evaluation unit are the accuracy in further processing, the speed in further processing, etc.

[0049] Based on the essential technical characteristics of the transmission elements G1-G4 and G1*-G4* stored in the data memory, the computer program product C can find at least one replacement transmission element G1*-G4* in the data memory R2. To do this, the computer program product C compares the digital information I of the specific transmission element G1-G4 with the digital information I* of replacement transmission elements G1*-G4* stored in the data memory R2. The computer program product C identifies at least one equivalent replacement transmission element G1*-G4* for the specific transmission element G1-G4 and loads the digital information I* of the replacement transmission element G1*-G4* from the data memory R2.

[0050] With the digital information I* of the replacement transmission element G1*-G4*, the replacement transmission element G1*-G4* is physically provided, for example by procurement, and the specified transmission element G1-G4 is replaced by the physically provided replacement transmission element G1*-G4* in the measuring system S.

[0051] In the first embodiment according to Fig. 8 The measuring system S (G1, G2, G3, G4) is replaced by the substitute transmission element G4* to form a substitute measuring system S* (G1, G2, G3, G4*). The measurement uncertainty U of the substitute measuring system S* increases due to the comparatively larger substitute measurement uncertainty contributions U41*-U44*. The increase in measurement uncertainty U from the measuring system S (G1, G2, G3, G4) to the substitute measuring system S* (G1, G2, G3, G4*) is in Fig. 8 marked by an arrow.

[0052] In the second embodiment according to Fig. 9In the measurement system S (G1, G2, G3, G4), the transfer element G2 is first replaced by the substitute transfer element G2* to form a first substitute measurement system S* (G1, G2*, G3, G4). The first substitute measurement system S* is then replaced by replacing the transfer element G1 with the substitute transfer element G1* to form a second substitute measurement system S* (G1*, G2*, G3, G4). The measurement uncertainty U of the substitute measurement system S* decreases due to the comparatively smaller substitute measurement uncertainty contributions U12* and U21*. The decrease in measurement uncertainty U from the measurement system S (G1, G2, G3, G4) to the first substitute measurement system S* (G1, G2*, G3, G4) and from there to the second substitute measurement system S* (G1*, G2*, G3, G4) is in Fig. 9 marked by an arrow. List of reference symbols

[0053] a) Identification of the transmission elements of the measurement chain b) Determination of the influence of the identified transmission elements on the measurement uncertainty of the measurement system c) Use of the determined influence elements to calculate the measurement uncertainty of the measurement system d) Determination of an identified transmission element with an extreme measurement uncertainty contribution e) Determination of a substitute transmission element with a substitute measurement uncertainty contribution for the identified transmission element A Number B Amount C Computer program product E11-E42 Determined influence element G1-G4 Transmission element G1*-G4*Substitute transmission element I, I* Digital information data K Measurement chain L Power R Computer system S Measuring system S* Substitute measuring system U Measurement uncertainty U11-U42 Measurement uncertainty contribution U11*-U42* Substitute measurement uncertainty contribution V Method R1 Data processing processor R2 Data storage R3, R3' Input unit R4 Output unit R5, R5'Communication Unit

Claims

1. A method (V) executed by a computer system (R) for determining the measurement uncertainty (U) of a measuring system (S); which measuring system (S) detects a physical measurement variable; wherein said measuring system (S) comprises a plurality of transmission links (G1-G4); and which transmission links (G1-G4) form a measuring chain (K) for detecting the physical measurement variable, wherein a transmission element (G1) is a sensor, a transmission element (G2) is a signal cable, a transmission element (G3) is an electric amplifier and a transmission element (G4) is an evaluation unit, wherein directly adjacent transmission links (G1-G4) are in a cause-and-effect relationship to one another in the measuring chain (K); and wherein the computer system (R) comprises a data processing processor (R1) and a computer program product (C), which computer program product (C) is executable in the data processing processor (R1) for carrying out the method; characterized by the steps of: a) input of information for identifying the transmission links (G1-G4) of the measuring chain (K) at an input unit (R3) and communication of the input information as digital information data (I) via at least one communication unit (R5, R5') to the data processing processor (R1) or calling up a digital information carrier with digital information data (I) of the transmission elements (G1-G4) of the measuring chain (K) stored therein and communicating the input information as digital information data (I) to the data processing processor (R1) via at least one communication unit (R5, R5'); reading the digital information data (I) by the computer program product (C); b) accessing a data memory (R2) of the computer system (R) by the computer program product (C) with predetermined influencing variables of transmission links (G1-G4) stored in the data memory (R2); reading in legible labels of influencing variables (E11-E42) of the identified transmission links (G1-G4) by the computer program product (C), and determining a relevance of the influencing variables (E11-E42) of the identified transmission links (G1-G4) for the measurement uncertainty (U) of the measuring system (S) by the computer program product (C); in that the computer program product (C) determines for each identified transmission link (G1-G4) at least one relevant influencing variable (E11-E42) attributed to the identified transmission link (G1-G4), wherein those influencing variables (E11-E42) are relevant, which influencing variables (E11-E42) have the largest contributions to the measurement uncertainty (U) of the measuring system (S) and which influencing variables (E11-E42) have a total contribution of at least 80% to the measurement uncertainty (U) of the measuring system (S); and that the computer program product (C) loads the determined influence quantity (E11-E42) from the data memory (R2; and c) using influencing variables (E11-E42) found to be relevant for calculating the measurement uncertainty (U) of the measuring system (S) by the computer program product (C).

2. The method (V) according to claim 1, characterized by a step: d) determining at least one identified transmission link (G1-G4) with an important measurement uncertainty contribution (U11-U42), which important measurement uncertainty contribution (U11-U42) is smaller or higher than at least one of the other measurement uncertainty contributions (U11-U42).

3. The method (V) according to claim 2, characterized by a step: e) determining at least one replacement transmission link (G1*-G4*) having a replacement measurement uncertainty contribution (U11*-U42*) for the at least one particular identified transmission link (G1-G4).

4. The method (V) according to claim 3, characterized in that the determined replacement transmission link (G1*-G4*) is physically provided; and in that the particular transmission link (G1-G4) is replaced in the measuring system (S) by the physically provided replacement transmission link (G1*-G4*).

5. The method (V) according to claim 3, characterized in that the calculated measurement uncertainty (U) is displayed on an output unit (R4).

6. A computer program product (C) for performing the method according to any of the claims 1 to 5, which computer program product (C) is loadable in a data processing processor (R1) of a computer system (R), characterized in that the computer program product (C) carries out steps a) to c).

7. The computer program product (C) according to claim 6, characterized in that for executing step a) the computer program product (C) reads in digital information data (I) for identifying the transmission links (G1-G4) of the measuring chain (K); the computer system (R) comprises an input unit (R3) and a communication unit (R5); information for identifying the transmission links (G1-G4) of the measuring chain (K) can be entered via the input unit (R3); and in that the communication unit (R5) communicates information entered at the input unit (R3) as digital information data to the data processing processor (R1).

8. The computer program product (C) according to claim 6, characterized in that for executing step a) the computer program product (C) reads in digital information data (I) for identifying the transmission links (G1-G4) of the measuring chain (K); the computer system (R) comprises a first input unit (R3), a second input unit (R3'), a first communication unit (R5) and a second communication unit (R5'); the first communication unit (R5) is a network; each input unit (R3, R3') is connected to the first communication unit (R5); information for identifying the transmission links (G1-G4) of the measuring chain (K) can be entered via the first input unit (R3); the first input unit (R3) calls a network address of the second input unit (R3') via the first communication unit (R5) and communicates input information as digital information data (I) to the second input unit (R3') called; and in that the second communication unit (R5') communicates digital information (I) communicated to the second input unit (R3') to the data processing processor (R1).

9. The computer program product (C) according to claim 6, characterized in that for executing step a) the computer program product (C) reads in digital information data for identifying the transmission links (G1-G4) of the measuring chain (K); the computer system (R) comprises at least a first input unit (R3), a second input unit (R3'), a first communication unit (R5) and a second communication unit (R5'); the first communication unit (R5) is a network; each input unit (R3, R3') is connected to the first communication unit (R5); the transmission links (G1-G4) comprise at least one information carrier; the information carrier stores digital information data (I) of the transmission links (G1-G4); the information carrier is connected to the first communication unit (R5) via the first input unit (R3); the computer program product (C) calls the network address of the first input unit (R3) in the network; the information carrier called in this way communicates digital information data (I) to the network address of the input unit (R3); and in that the communication unit (R5) communicates digital information (I) communicated to the second input unit (R3) to the data processing processor (R1).

10. The computer program product (C) according to any of the claims 6 to 9, characterized in that the computer system (R) comprises a data memory (R2); wherein for predetermined influencing variables of transmission links (G1-G4) best influence estimates and measurement uncertainty contributions (U11-U42) associated with the best influence estimates are stored in the data memory (R2); for carrying out step c) the computer program product (C) retrieves for each determined influencing variable (E11-E42) a measurement uncertainty contribution (U11-U42) associated with the best influence estimate of the determined influencing variable (E11-E42) from the data memory (R2); and in that the computer program product (C) calculates the measurement uncertainty (U) of the measuring system (S) by summing up the squares of the measurement uncertainty contributions (U11-U42) and calculating a square root of the sum.

11. The computer program product (C) according to claim 10, characterized in that for carrying out a step d) the computer program product determines at least one identified transmission link (G1-G4) that has an important measurement uncertainty contribution (U11-U42), which important measurement uncertainty contribution (U11-U42) is smaller or higher than at least one of the other measurement uncertainty contributions (U11-U42).

12. The computer program product (C) according to claim 11, characterized in that the computer system (R) comprises a data memory (R2); wherein digital information data (I*) of replacement transmission links (G1*-G4*) are stored in the data memory (R2), wherein a replacement transmission link (G1*-G4*) is equivalent if it matches with the particular identified transmission link (G1-G4) in essential characteristics and if it differs from the particular transmission link (G1-G4) in only at least one measurement uncertainty contribution (U11-U42); and in that the computer program product (C) compares digital information (I) of the particular transmission link (G1-G4) with digital information (I*) of replacement transmission links (G1*-G4*) stored in the data memory (R2).

13. The computer program product (C) according to claim 12, characterized in that for carrying out a step e) the computer program product (C) determines that a replacement transmission link (G1*-G4*) is equivalent to the particular transmission link (G1-G4); and in that the computer program product (C) retrieves digital information (I) of the determined replacement transmission link (G1*-G4*) from the data memory (R2).