Measuring system

Abstract

The measuring system is used for sensing two temporally variable primary measured variables (x1, x2) and / or secondary measured variables (y1) derived therefrom. It comprises a measuring electronics, an active sensor element (C1), a passive sensor element (R1) and an electrical connection line. The sensor element (C1) generates a voltage dependent on x1, while the sensor element (R1) varies its resistance dependent on x2. Within a defined interval (t1), measurement electronics drive a measurement current through R1 and interrupt the current before (t2) and after (t3) the interval, as a result of rising and falling current edges occurring in transition intervals (t4, t5). Furthermore, the measuring electronics temporarily sense and analyse the voltages (u1, u2), and the measurement is effected in a specific time interval in order to allow a fault-free and accurate evaluation.

Description

Technical Field

[0001] The present invention relates to a measurement system for measuring two (time-variable) primary (process) analytes of a fluid analyte and / or for measuring a (time-variable) secondary (process) analyte obtained from at least one of the primary (process) analytes. Background Technology

[0002] In U.S. patent applications 2003 / 0061887, 2004 / 0216532, 2009 / 0038406, 2022 / 0057240, WO2004 / 023081, WO 2022 / 128418 and (unpublished) German patent application 102022127160.9, the measurement system is described as being used to measure a time-variable primary first (process) analyte of a fluid analyte flowing in a (process) line, namely, a time-variable, particularly periodic, static pressure and / or a time-variable change or rate of change of the same pressure, and / or to measure a (time-variable) secondary (process) analyte derived from the same primary (process) analyte, in this case, the flow velocity and / or volumetric flow rate of the fluid analyte guided in the (process) line.

[0003] Each measurement system in the measurement system designed here as a vortex flowmeter (in a compact design) includes measurement system electronics, at least one first sensor element for detecting a first primary (process) measured variable, and at least one passive second sensor element for detecting a second primary (process) measured variable—i.e., temperature, which is variable over time—that is, a variable different from the first primary (process) measured variable (serving as an auxiliary measured variable). The first and second sensor elements are each electrically connected to the corresponding measurement system electronics via electrical connection lines (forming the first and second measurement channels of the respective measurement systems, respectively). Furthermore, the first sensor element is configured (in conjunction with the measurement system electronics) to generate or set a first electrical (measurement) voltage depending on the first primary measured variable, and the second sensor element is configured (in conjunction with the measurement system electronics) to generate or set a second electrical (measurement) voltage depending on the second primary measured variable.

[0004] In each of the aforementioned measurement systems, the measurement system electronics are housed in a protective electronic housing, for example, shockproof and / or weatherproof, and are each configured to determine one or more (digital) measured values ​​of primary and / or secondary (process) measured variables based on a (time-variable) first electrical (measuring) voltage and a second electrical (measuring) voltage, and output them as qualified measured values ​​of the measurement system. In the measurement system shown here, the measurement system electronics are also specifically designed to determine, at least based on the first electrical (measuring) voltage, the frequency of at least temporarily periodic pressure fluctuations within the flowing analyte—i.e., pressure fluctuations within the Karman vortex street formed in the flow of the analyte—used as a secondary (process) measured variable, and to determine, based on the same (vortex) frequency and a (temperature-dependent) second electrical (measuring) voltage, the measured value of the volume and / or mass flow of the analyte used as a secondary (process) measured variable. For example, the measurement system electronics can also be configured to determine the measured value of the (static) pressure of the (flowing) fluid analyte, which serves as the first primary (process) measured variable, based on a first electrical (measuring) voltage and a second electrical (measuring) voltage. Typically, the type of measurement system discussed is primarily designed as a low-power measurement system, for example, such that the corresponding measurement system electronics operate at least temporarily with an electrical (rated) power of less than 100 mW; this is particularly true when the measurement system electronics, or the measurement system formed therefrom, are connected via a current loop interface to a (4-20 mA) two-wire line suitable for transmitting electrical power and the measured value.

[0005] As shown in US-A 2003 / 0061887, US-A 2004 / 0216532, US-A 2009 / 0038406, and US-A 2022 / 0057240, the first sensor element can be designed, for example, as a capacitive (passive) sensor element, such that the sensor element has an electrical (sensor) capacitance and is configured to follow changes in a first primary (process) measured variable by means of a (measuring) capacitor—for example, formed using an electrode geometry that varies depending on the first primary measured variable. Furthermore, the measurement system electronics can be accordingly configured to charge or maintain a charge on the aforementioned (sensor) capacitor to generate a first electrical (measuring) voltage—for example, by means of a suitable charge-to-voltage converter (charge amplifier). In the aforementioned measurement system, the first sensor element is formed using at least one (measuring) capacitor, which is designed, for example, as a parallel-plate capacitor, and has an electrode geometry that varies depending on the first primary measured variable. For example, the first sensor element can also be formed by means of a (plate) capacitor having a dielectric that varies depending on the first primary measured variable, or it can also be a piezoelectric or current (active) sensor element. The second sensor element can typically be a passive (temperature) resistive sensor element, such that the sensor element has a temperature-dependent electrical (sensor) resistance, for example, a platinum measuring resistor (standardized according to EN IEC 60751), and is designed to use changes in this resistance to follow changes in the second primary measured variable. To generate a second electrical (measuring) voltage, the measurement system electronics can also be configured to excite the second sensor element, i.e., drive an (applied) electrical (measuring) current with a current intensity typically between approximately 0.05 mA and 0.5 mA through the second sensor element and its connection wires electrically connected to the measurement system electronics—for example, establishing a corresponding (resistance-proportional) voltage drop across the second sensor element.

[0006] In order to connect the first and second sensor elements, or the measurement system formed therewith, to the corresponding process or its corresponding analyte, the type of measurement system discussed typically also includes a metallic (process) coupling element, which is formed, for example, by means of a membrane and / or sleeve and / or plate, and is designed to be in contact (during operation of the measurement system) with the corresponding analyte, for example by the substance flowing onto and / or around it, and in particular, to have a (coupled element) temperature depending on the temperature of the analyte and / or to have a (elastic) strain depending on the pressure of the analyte.

[0007] In the measurement systems shown in US-A 2003 / 0061887, US-A 2004 / 0216532, US-A 2009 / 0038406, US-A 2022 / 0057240, and WO-A 2022 / 128418, the (process) coupling element is partially arranged within a (housing) connection fitting for holding the aforementioned electronic (protective) housing on a (process) line or on a measuring tube integrated therein, for example by means of a flange connection and / or in a tubular form, releasably connected to the electronic (protective) housing, and / or (mechanically) connected to it at a connection fitting remote from the electronic housing, and the aforementioned connection line is at least partially routed within the (housing) connection fitting. Furthermore, the (process) coupling element shown here is formed by means of a membrane-like deformable body and a paddle-shaped sensor plate molded thereon, and is specifically designed to be at least partially inserted into the lumen of a tube (for guiding the fluid analyte), for example, such that the (process) coupling element is inserted into the lumen through an opening in the wall of the closed tube and is (removably) fixed to the same tube wall. The coupling element can also be formed and arranged, for example, using a vibrating fork or vibrating rod, and can be at least partially inserted into the lumen of a container such as a tank or silo (for guiding the fluid analyte).

[0008] Furthermore, the coupling element is mechanically coupled to the first sensor element such that the first electrical (measured) voltage depends on the strain of the coupling element, or a change in the strain of the coupling element causes a change in the first electrical (measured) voltage—for example, by rigidly connecting at least one (movable) capacitor electrode of the (measuring) capacitor to the coupling element. Especially in the aforementioned case where the first sensor element is formed by means of at least one (measuring) capacitor, the first sensor element can also be an (integrated) component of the coupling element, for example, such that at least one (movable) capacitor electrode of the (measuring) capacitor is formed through the coupling element. Furthermore, the coupling element and the second sensor element are at least thermally coupled to each other, particularly both thermally and mechanically coupled, such that the second electrical (measured) voltage depends on the temperature of the coupling element, or a change in the temperature of the coupling element causes a change in the electrical (sensor) resistance of the second sensor element.

[0009] One drawback of the type of measurement system discussed is that the aforementioned connecting lines—at least when they are at least partially installed within the connecting fittings—are spaced less than 5 mm apart, and thus can be capacitively coupled to a considerable extent. Due to this coupling, the measuring current used to generate the second electrical (measuring) voltage can also cause interference in the first measuring channel through the second sensor element, thus affecting the first electrical (measuring) voltage and therefore the overall measurement accuracy of the measurement system; this is especially true if the measuring current changes abruptly, for example, by switching it on or off. To avoid the resulting measurement errors, switching operations that affect the corresponding measuring current are avoided in such a measurement system during the determination of the measured value, or conversely, the measuring current is kept as constant as possible to determine the measured value. Therefore, the total electrical power required for the operation of the aforementioned first and second measuring channels can reach approximately 0.5 to 2 mW, and thus, in the case of low-power measurement systems, is (occasionally) greater than 1% of the total available—although already low—electrical power (<100 mW). Summary of the Invention

[0010] Starting from the aforementioned prior art, one object of the present invention is to improve the type of measurement system discussed, such that the electrical power required to determine the measured value can be periodically reduced from the (maximum) electrical power required for the operation of the first and second measurement channels to a relatively low (minimum) electrical power, while still maintaining sufficiently high measurement accuracy or thus a sufficiently high update rate for the determined measured value.

[0011] To achieve this objective, the present invention comprises a measurement system for measuring a (time-variable) first primary (process) analyte, such as the (static) pressure of a fluid analyte (carried in an online manner and / or held in a container) and / or the time-variable change of that pressure, and a (time-variable) second primary (process) analyte different from the first primary (process) analyte, such as the temperature of the fluid analyte (carried in an online manner), and / or for measuring a (time-variable) secondary (process) analyte derived from at least one of the first and second primary (process) analytes, such as the mass flow rate of a fluid analyte carried in an online manner or the fill level of a fluid analyte held in a container. The measurement system includes: The measurement system electronics, for example, operate at a maximum power of less than 1W (watts) and / or are connected to a 2-wire system (4-20mA). At least one first sensor element (C1), such as capacitive and / or passive, for detecting the first primary (process) measured variable. At least one passive second sensor element (R1), such as a resistive element, is used to detect the measured variable in the second primary (process). And the first electrical connection, the second electrical connection, the third electrical connection, and the fourth electrical connection, for example, each being (at least) partially unshielded and / or not twisted together. The first sensor element is connected to the electronic components of the measurement system via a first connecting line and a second connecting line (forming the first measurement channel of the measurement system), for example, by a feedthrough placed in the middle. The second sensor element is connected to the measurement system electronics via a third and fourth connecting line (forming the second measurement channel of the measurement system), for example, by a feedthrough placed in the middle. Furthermore, at least one of the first and second connecting lines—for example, each of them—is capacitively (signal) coupled to at least one of the third and fourth connecting lines—for example, each of them—for example, by making the minimum distance between at least one of the first and second connecting lines and at least one of the third and fourth connecting lines less than 5 mm. The first sensor element is configured, for example, in conjunction with measurement system electronics, to generate and / or adjust a first electrical (measurement) voltage depending on the first primary (process) measured variable. Furthermore, the second sensor element has an electrical (sensor) resistance, which, for example, is not less than 90 ohms at a temperature of 20°C. And / or no more than 1.1k It is configured to follow the change in the second primary measured variable with the change in the same resistance. The measurement system electronics are configured to temporarily record and evaluate a first electrical (measured) voltage, for example, by digitizing it and / or determining a (digital) first (voltage) measurement value representing the (measured) voltage. The electronic components of the measurement system are configured as follows: A temporary voltage drop across the second sensor element is caused to excite the second sensor element, i.e., during a predetermined first (excitation) time interval t1 lasting for, for example, not less than 10 ms, a driving (measuring) current—e.g., an applied and / or constant and / or a maximum current having not less than 0.1 mA and / or achieving a maximum electrical power of not less than 0.4 mW in the second sensor element—is passed through the second sensor element and the third and fourth connecting lines. During a second time interval t2 preceding the first time interval and during a third time interval t3 following the first (excitation) time interval, the second sensor element is not excited or no driving (measuring) current is passed through the second sensor element and the third and fourth connecting lines. The wiring is configured such that the (measured) current has a (rising) first current edge, for example, at least temporarily and / or with an arithmetically averaged current rise rate of at least 0.1 mA / µs, during a fourth (transition) time interval that immediately follows the second (excitation) time interval and immediately precedes the first (excitation) time interval and lasts for example, at least 1 µs (µs), and the (measured) current has a (falling) second current edge, for example, at least temporarily and / or with an arithmetically averaged current fall rate of at least 0.1 mA / µs, during a fifth (transition) time interval that immediately follows the first (excitation) time interval and immediately precedes the third (excitation) time interval and lasts for example, at least 1 µs (µs), during a fifth (transition) time interval. Furthermore, the measurement system electronics are configured to detect and evaluate a second electrical (measured) voltage that depends on the voltage drop across the second sensor element during a first (excitation) time interval t1, for example, by digitizing it and / or determining a (digital) second (voltage) measurement value representing the (measured) voltage; The measurement system electronics are configured to determine one or more (digital) measured values ​​of a first primary (process) measured variable and / or one or more (digital) measured values ​​of a secondary (process) measured variable based at least on a first electrical (measuring) voltage, such as based on both a first electrical (measuring) voltage and a second electrical (measuring) voltage; for example, to determine them and output them as qualified measured values ​​of the measurement system. Furthermore, the measurement system electronics are configured, for example, to avoid measurement errors caused by (signal) coupling from the third and / or fourth connection lines to the first and / or second connection lines in the measured value determined for the first measured variable: The (qualified) measured value of the first primary (process) measured variable based on the first (measurement) voltage detected during the fourth (transition) time interval and the fifth (transition) time interval is not output. And / or not based on the first electrical (measurement) voltage applied during the fourth (transition) time interval and the fifth (transition) time interval to determine the measured value of the first primary (process) measured variable. And / or not output the (qualified) measured value of the secondary (process) variable determined based on the first (measurement) voltage detected during the fourth (transition) time interval and the fifth (transition) time interval. And / or the measured value of the secondary (process) measured variable is not determined based on the first electrical (measurement) voltage applied during the fourth (transition) time interval and the fifth (transition) time interval. And / or determine the (qualified) measured values ​​of the first primary (process) measured variable and / or secondary (process) measured variable during the fourth (transition) time interval based on the first (measured) voltage previously detected during the second time interval. And / or determine the (qualified) measured values ​​of the first primary (process) measured variable and / or secondary (process) measured variable during the fifth (transition) time interval based on the first (measured) voltage previously detected during the first time interval.

[0012] Furthermore, the present invention also comprises: using a measurement system to measure a first primary (process) analyte variable (e.g., time-varying (static) pressure) of a fluid analyte (carried in an online manner or held in a container), and a second primary (process) analyte variable (different from the first analyte variable), such as time-varying temperature.

[0013] According to a first embodiment of the measurement system of the present invention, the measurement system electronics are further provided to be configured as follows: It does not output the (qualified) measured value of the first primary (process) measured variable based on the first (measured) voltage detected during the (excitation) time interval. And / or not based on the first electrical (measurement) voltage applied during the (excitation) time interval to determine the measured value of the first primary (process) measured variable. And / or not output the (qualified) measured value of the secondary (process) measured variable determined based on the first (measured) voltage detected during the (excitation) time interval. And / or not based on the first electrical (measurement) voltage applied during the (excitation) time interval to determine the measured value of the secondary (process) measured variable. Further developing this embodiment of the invention, the measurement system electronics are also configured to determine (qualified) measured values ​​of the first primary (process) measured variable and / or the secondary (process) measured variable based on the first (measurement) voltage detected during the first time interval, and / or output (qualified) measured values ​​of the first primary (process) measured variable and / or the secondary (process) measured variable determined based on the first (measurement) voltage detected during the (excitation) time interval.

[0014] According to a second embodiment of the measurement system of the present invention, a first sensor element is further provided to have an electrical (sensor) capacitance of, for example, not less than 10 pF and / or not greater than 100 pF at a temperature of 20°C, and is configured to follow the change of the first primary (process) measured variable with the same change in (sensor) capacitance. The measurement system electronics are configured to charge or maintain a charge on the capacitance of the first sensor element, for example, at least during a second and a third time interval, to generate a first electrical (measurement) voltage. Further developing this embodiment of the invention, the measurement system electronics are also arranged such that the first electrical (measurement) voltage is substantially proportional to the charge of the (sensor) capacitance of the first sensor element.

[0015] According to a third embodiment of the measurement system of the present invention, the measurement system electronics are further provided to be configured to determine (voltage) measured values ​​representing a first (measured) voltage, for example, to determine them and store them in a (volatile) digital data storage device. Further developing this embodiment of the invention, the measurement system electronics are further configured to use one or more (voltage) measured values ​​representing the first (measured) voltage to determine one or more measured values ​​of a second primary (process) measured variable.

[0016] According to a fourth embodiment of the measurement system of the present invention, the measurement system electronics are further provided to be configured to determine (voltage) measured values ​​representing a second (measured) voltage, for example, to determine them and store them in a (volatile) digital data storage device. Further developing this embodiment of the invention, the measurement system electronics are also configured to use one or more (voltage) measured values ​​representing the second (measured) voltage to determine one or more measured values ​​of a first primary (process) measured variable, and / or to use one or more (voltage) measured values ​​representing the second (measured) voltage to determine one or more measured values ​​of a first primary (process) measured variable, and / or to use one or more (voltage) measured values ​​representing the second (measured) voltage to determine one or more measured values ​​of a second primary (process) measured variable.

[0017] According to a fifth embodiment of the measurement system of the present invention, the measurement system electronics are further provided to determine one or more (digital) measured values ​​of a second primary (process) measured variable based on a second electrical (measurement) voltage. For example, determining at least one measured value of a first primary (process) measured variable and / or a secondary (process) measured variable, each measured value serving as an auxiliary measured value, i.e., determining them and storing them in a (volatile) digital data storage device. Further developing this embodiment of the invention, the measurement system electronics are further configured to determine one or more measured values ​​of the first primary (process) measured variable using one or more measured values ​​of the second primary (process) measured variable.

[0018] According to a sixth embodiment of the measurement system of the present invention, the measurement system electronics are further provided to determine one or more (digital) measured values ​​of a second primary (process) measured variable based at least on a second electrical (measurement) voltage, for example based on both the second electrical (measurement) voltage and the first electrical (measurement) voltage, for example, to determine and output them as qualified measured values ​​of the measurement system.

[0019] According to a seventh embodiment of the measurement system of the present invention, each of the first connecting line and the second connecting line is at least partially unshielded, for example, completely unshielded.

[0020] According to an eighth embodiment of the measurement system of the present invention, each of the third and fourth connecting lines is further provided to be at least partially unshielded, for example, completely unshielded.

[0021] According to a ninth embodiment of the invention, each of the first connecting line and the second connecting line is at least partially formed by means of conductor traces arranged on a (flexible) printed circuit board.

[0022] According to a tenth embodiment of the measurement system of the present invention, each of the third and fourth connecting lines is at least partially formed by means of conductor traces arranged on a (flexible) circuit board.

[0023] According to an eleventh embodiment of the measurement system of the present invention, each of the first connecting line, the second connecting line, the third connecting line and the fourth connecting line is formed at least partially by means of conductor traces arranged on one and the same (flexible) circuit board.

[0024] According to a twelfth embodiment of the measurement system of the present invention, a first connecting line and a second connecting line are further provided to extend at least partially parallel to each other.

[0025] According to a thirteenth embodiment of the measurement system of the present invention, a third connecting line and a fourth connecting line are further provided to extend at least partially parallel to each other.

[0026] According to a fourteenth embodiment of the measurement system of the present invention, the first connecting line and the third connecting line are further provided to extend at least partially parallel to each other.

[0027] According to a fifteenth embodiment of the measurement system of the present invention, the first connecting line and the fourth connecting line are further provided to extend at least partially parallel to each other.

[0028] According to a sixteenth embodiment of the measurement system of the present invention, the first connecting line, the second connecting line, the third connecting line and the fourth connecting line are further provided to extend at least partially parallel to each other.

[0029] According to a seventeenth embodiment of the measurement system of the invention, the measurement system electronics have at least one operational amplifier, such as a FET or CMOS operational amplifier, wherein a first sensor element is electrically connected to the (high impedance) (voltage) input of the operational amplifier by means of a first connection line and a second connection line, for example by forming a charge-to-voltage converter of the measurement system electronics, and wherein the operational amplifier is configured to supply a first electrical (measured) voltage at its (voltage) output (when the measurement system electronics are operating in a first operating mode). Further developing this embodiment of the invention, the operational amplifier has, for example, a switchable (feedback) capacitor (Cf) whose (voltage) output is fed back to its (voltage) input. Advantageously, the (feedback) capacitor (Cf) may have a (feedback) capacitance of not less than 0.1 pF and / or not greater than 100 pF.

[0030] According to an eighteenth embodiment of the measurement system of the present invention, the measurement system electronics are further provided to have at least one, for example, switchable (electronic) current source, wherein a second sensor element is electrically connected to the (current) output of the current source by means of a third and a fourth connecting line, and wherein the current source is configured to supply (measurement) current.

[0031] According to a nineteenth embodiment of the measurement system of the present invention, the measurement system electronics are further provided to have at least one, for example, switchable (electronic) voltage source, wherein a second sensor element is electrically connected to the output of the voltage source by means of a third and a fourth connecting line, and wherein the voltage source is configured to drive (measure) current.

[0032] According to a twentieth embodiment of the measurement system of the present invention, the measurement system electronics are further provided to determine the sensor resistance of the second sensor element based on a second (measured) voltage.

[0033] According to the twenty-first embodiment of the present invention, a measurement system electronics device is further provided having at least one (reference) resistive element having, for example, a resistance of not less than 90 ohms at a temperature of 20°C. And / or no more than 1.1k The third electrical (reference) resistor is electrically connected to the second sensor element, for example, in series with the second sensor element. Further developing this embodiment of the invention, the measurement system electronics are configured to detect and evaluate a third electrical (reference) voltage depending on the voltage drop across the (reference) resistor element during a first (excitation) time interval, for example, by digitizing it and / or determining a (digital) third voltage measurement representing the reference voltage. Advantageously, the measurement system electronics can also be configured to determine the (sensor) resistance of the second sensor element based on the third (reference) voltage, for example, based on the second and third voltages and the (reference) resistor and / or proportionally.

[0034] According to a twenty-second embodiment of the present invention, a measurement system electronics is further provided to determine, at least based on a first electrical (measurement) voltage, the frequency of at least temporarily periodic pressure fluctuations (used as a secondary measured variable) within the fluid measured substance, for example, pressure fluctuations within a Karman vortex street formed in the flow of the measured substance.

[0035] According to a twenty-third embodiment of the present invention, a measurement system electronics is further provided to determine the measured value of the temperature of a (substance being measured) (used as a second primary measured variable) based at least on a second electrical (measurement) voltage, for example, a flowing fluid substance being measured.

[0036] According to a twenty-fourth embodiment of the present invention, a measurement system electronics is further provided to determine the measured value of the (static) pressure (used as a first primary measured variable) of the (flowing) fluid measured substance based on a first electrical (measuring) voltage and a second electrical (measuring) voltage.

[0037] According to a twenty-fifth embodiment of the present invention, a measurement system electronics is further provided to determine the measured value of the volumetric flow rate of the flowing (fluid) substance (used as a secondary measured variable) based on a first electrical (measuring) voltage and a second electrical (measuring) voltage.

[0038] According to a twenty-sixth embodiment of the present invention, a measurement system electronics is further provided to determine the measured value of the mass flow rate (used as a secondary measured variable) of the flowing (fluid) analyte based on a first electrical (measuring) voltage and a second electrical (measuring) voltage.

[0039] According to the twenty-seventh embodiment of the invention, the first sensor element is further provided to be formed by means of at least one (measuring) capacitor, for example designed as a parallel plate capacitor, for example having (capacitor) electrode geometry that varies depending on the first primary measured variable and / or having a dielectric that varies depending on the first primary measured variable.

[0040] According to the twenty-eighth embodiment of the present invention, the second sensor element (R1) is further provided to be formed by means of at least one platinum measuring resistor, such as Pt100 and / or Pt1000.

[0041] According to a first further development of the invention, the measurement system further includes at least one (electrical) feedthrough, such as explosion-proof (Ex-d) and / or conforming to international standard IEC 60079-1:2014.

[0042] According to a first embodiment of a further development of the present invention, a first connecting line, a second connecting line, a third connecting line, and a fourth connecting line are provided to be routed within a feedthrough.

[0043] According to a second embodiment of the first further development of the invention, it is provided that, for example, unshielded (connection) pins are electrically connected to the first connection line, the second connection line, the third connection line, and the fourth connection line.

[0044] According to a third embodiment of the first further development of the present invention, a feedthrough is provided that is placed in the middle between the first connecting line, the second connecting line, the third connecting line and the fourth connecting line.

[0045] According to a second further development of the invention, the measurement system further includes an electronic (protective) housing for the measurement system electronics, such as one that is resistant to explosion pressure (Ex-d) and / or conforms to international standard IEC 60079-1:2014.

[0046] According to a third further development of the invention, the measuring system further includes a (housing) connecting fitting, which, for example by means of a flange connection and / or in a tubular form, is releasably connected to the electronic (protective) housing. It is also advantageous that the first, second, third, and fourth connecting lines are at least partially routed within the (housing) connecting fitting, for example, such that they extend at least partially parallel to each other.

[0047] According to a fourth further development of the invention, the measurement system further includes a (process) coupling element, which is formed, for example, by means of a membrane and / or a sleeve and / or a plate, and is designed to be contacted (during operation of the measurement system) by a fluid analyte, for example by said analyte flowing onto and / or around it, such that the (process) coupling element has a (coupling element) temperature depending on the temperature of the analyte and / or such that the (process) coupling element has a (elastic) strain depending on the pressure of the analyte.

[0048] According to a first embodiment of the fourth further development of the invention, a coupling element is provided to respond to changes in the temperature of the analyte as the temperature of the coupling element changes, for example, such that the temperature of the coupling element deviates from the steady-state temperature of the analyte in steady state by less than 2 K (Kelvin).

[0049] According to a second embodiment of the fourth further development of the invention, a coupling element is provided that is configured to respond to changes in the pressure of the substance (the measured substance) using, for example, biaxial and / or elastic strain.

[0050] According to a third embodiment of the fourth further development of the invention, a coupling element is provided, which is arranged to be at least partially inserted into the lumen of a tube (for guiding the fluid analyte), for example, inserted into the lumen through an opening in the tube wall that closes the lumen and is (releasably) secured to the same tube wall.

[0051] According to a fourth embodiment of a further development of the invention, a coupling element is provided, which is arranged to be at least partially inserted into the lumen of a container (for guiding the fluid analyte), such as a can, for example inserted into the lumen through an opening in the container wall that closes the lumen and is (releasably) secured to the same container wall.

[0052] According to a fifth embodiment of the fourth further development of the invention, the coupling element is provided to be at least partially, for example entirely, composed of metal, such as (stainless) steel and / or nickel-based alloys.

[0053] According to a sixth embodiment of the fourth further development of the invention, the coupling element and the first sensor element are provided to be coupled to each other at least mechanically, for example, such that the first electrical (measured) voltage depends on the strain of the coupling element or such that a change in the strain of the coupling element causes a change in the first electrical (measured) voltage.

[0054] According to a seventh embodiment of the fourth further development of the present invention, a first sensor element is provided as an (integrated) assembly of a coupling element, for example, such that a first electrical (measured) voltage depends on the strain of the coupling element or such that a change in the strain of the coupling element causes a change in the first electrical (measured) voltage.

[0055] According to the fourth further development of the invention, an eighth embodiment further provides that the coupling element is partially arranged within the (housing) connection fitting of the measurement system, which is releasably connected to the electronic (protective) housing of the measurement system, for example by means of a flange connection and / or in a tubular form, and (mechanically) connected to the connection fitting (e.g., at the fitting end away from the electronic housing).

[0056] According to a fourth further development of the ninth embodiment of the invention, a first sensor element is further provided to be formed by means of at least one (measuring) capacitor, for example designed as a parallel plate capacitor, for example having (capacitor) electrode geometry that varies depending on the first primary measured variable and / or having a dielectric that varies depending on the first primary measured variable, wherein at least one, for example a movable (capacitor) electrode of the (measuring) capacitor is mechanically connected to or formed by means of a coupling element, and / or wherein the coupling element and the second sensor element are at least thermally coupled to each other, for example both thermally and mechanically coupled, for example such that the second electrical (measuring) voltage depends on the temperature of the coupling element or such that a change in the temperature of the coupling element causes a change in the electrical (sensor) resistance of the second sensor element.

[0057] According to a fifth further development of the invention, the measurement system further includes an electronic (protective) housing for the measurement system electronics, such as one that is resistant to explosion pressure (Ex-d) and / or conforms to international standard IEC 60079-1:2014.

[0058] The advantage of this invention is that, without compromising the measurement accuracy of the measurement system or its (measured value) update rate, the measurement current required to determine the second primary measured variable can be switched on or off in a manner optimized for the operation of the measurement system electronics. Attached Figure Description

[0059] The invention and its advantageous embodiments are explained in more detail below with reference to the exemplary embodiments shown in the accompanying drawings. In all the drawings, the same or identical components or functions are provided with the same reference numerals; for clarity, or if they appear obvious for other reasons, the aforementioned reference numerals are omitted in subsequent drawings. Further advantageous embodiments or developments, especially combinations of the aspects of the invention initially explained separately, further arise from the drawings and / or the claims themselves.

[0060] The diagram provides a detailed explanation of: Figure 1 A perspective side view of an exemplary embodiment of the measurement system according to the present invention is shown; Figure 2 It shows that according to Figure 1 A schematic partial cross-sectional side view of the measurement system; Figure 3 It shows the applicability according to Figure 1 A schematic diagram of an exemplary embodiment of the measurement system electronic device of the measurement system; Figure 4 The time graph shows the data based on... Figure 3 The measurement system uses electronic devices to measure voltage or current curves. Detailed Implementation

[0061] Figure 1 , Figure 2 and Figure 3 An exemplary embodiment of a measurement system is schematically illustrated for measuring a (time-variable) first primary (process) analyte variable, particularly the (static) pressure and / or time-variable change of the pressure of a fluid analyte carried in an online line and / or held in a container, and a (time-variable) second primary (process) analyte variable x2, different from the first primary (process) analyte variable x1, particularly the temperature of the fluid analyte carried in an online line, and / or for measuring a (time-variable) secondary (process) analyte variable y1 derived from at least one of the first and second primary (process) analytes variables, particularly the volumetric or mass flow rate of the fluid analyte carried in an online line or the fill level of a fluid analyte held in a container, such as a gas, liquid, or dispersion. The aforementioned line and / or container may each be designed as, for example, a device assembly of a heat supply network or turbine circuit, and thus the analyte may be, for example, steam, particularly saturated or superheated steam, or also, for example, condensate discharged from a steam line. However, the substance being tested can also be, for example, (compressed) natural gas or biogas, or, for example, (drinking) water; therefore, the pipes and / or containers can also be, for example, components of a natural gas or biogas plant, a gas supply network, or a water supply network. According to Figure 1 or Figure 2 The exemplary embodiment shown may include, for example, a (measuring) tube 3, which can be inserted into the aforementioned line during the process; it may also be designed as a (rigid) pipe and have (metal) walls 3 formed by the tube. A closed lumen 3', wherein the tube 3 or its lumen extends from the inlet end 3+ to the outlet end 3#, and is designed to guide the flow of the analyte (in the connecting line) or through which the same analyte passes in the main flow direction of the measurement system during operation. Figure 1 In the exemplary embodiment shown in Or 2, flanges are present at both the inlet end 3+ and the outlet end 3#, which in each case are used to create a leak-free flange connection with the corresponding flange on the inlet or outlet side segment of the line. Furthermore, as Figure 1 As shown in Figure 2, line 3 can be substantially straight, for example, in the form of a hollow cylinder with a circular cross-section at least partially, such that line 3 has an imaginary straight longitudinal axis L connecting the inlet end 3+ and the outlet end 3#. Figure 1 and Figure 2The measurement system shown by way of example is specifically designed as a (vortex counting) vortex flow meter, and accordingly also has a baffle 4 arranged in, for example, a prismatic or cylindrical cavity 3', which is designed to cause the flowing fluid to swirl, such that vortices with a separation frequency fv (fv~u) depending on the instantaneous flow velocity u of the fluid are generated in the fluid flowing through it, or a Karman vortex street is formed in the fluid flowing downstream of the baffle 4.

[0062] The measurement system according to the invention comprises: at least one measurement system electronics 2, which can operate, for example, with an energy flow of less than 360 W / h and / or with a maximum electrical power of less than 1 W (watt) – particularly less than 0.1 W; at least one first sensor element C1, for example capacitive and / or passive, for detecting a first primary (process) measured variable; and at least one second sensor element R1, for example resistive, for detecting a second primary (process) measured variable. Specifically, in the aforementioned case where the measurement system is designed as a vortex flowmeter, the first and second sensor elements can be designed or configured, for example, to detect the first and second primary (process) parameters of the fluid downstream of the aforementioned dam (during operation of the measurement system) or the Karman vortex street formed there, for example, such that the first primary (process) parameter x1 is (static) pressure or its change over time, with a (vortex) shedding rate or frequency (f) proportional to the fluid flow velocity u. V The fluctuation, and / or the second primary (process) parameter y1, is the (fluid) temperature of the (swirling) analyte. .

[0063] The measurement system electronics 2—which may be programmable, for example—may have interface circuitry, particularly designed as a TTY interface, for both wired power and wired signal transmission or measurement data transfer. By means of this interface circuitry, the measurement system (forming current loop 2L) can be electrically connected to a higher-level evaluation and power supply electronics that provides the electrical energy required by the measurement system during operation. For example, the measurement system electronics 2 can be configured to draw power from the aforementioned current loop 2L by means of (load) modulation of the electrical (loop) current driven by the evaluation and power supply electronics in current loop 2L and to transmit (measurement) data, for example, in the form of (4-20mA) unit signals conforming to DIN IEC 60381-1:1985-11. For temporary storage of digital (measurement) data, the measurement system electronics 2 may, for example, include at least one (volatile) digital data storage device (RAM).

[0064] To electrically connect the first sensor element C1 and the second sensor element R1 to the measurement system electronics 2, which can also be formed by means of at least one microprocessor (µC), the measurement system according to the invention further includes a first electrical connection line 401, a second electrical connection line 402, a third electrical connection line 403, and a fourth electrical connection line 404, particularly untwisted electrical connection lines. According to another embodiment of the invention, each of the first connection line 401 and the second connection line 402 and / or each of the third connection line 403 and the fourth connection line 404 is at least partially unshielded, and for example, completely unshielded, particularly for cost reasons, and / or the connection lines 401, 402, 403, and 404 are arranged, particularly for spatial reasons, such that the minimum distance between at least one of the first connection line 401 and the second connection line 402 and at least one of the third connection line 403 and the fourth connection line 404 is less than 5 mm. The first connection line 401 and the second connection line 402 and / or the third connection line 403 and the fourth connection line 404 can also be formed, for example, at least partially, by means of conductor traces arranged on a (flexible) printed circuit board. According to another embodiment of the invention, the first connecting line 401 and the second connecting line 402 and / or the third connecting line 403 and the fourth connecting line 404 and / or the first connecting line 401 and the third connecting line 403 and / or the first connecting line 401 and the fourth connecting line 404 extend at least partially parallel to each other, in particular such that the first connecting line 401, the second connecting line 402, the third connecting line 403 and the fourth connecting line 404 extend at least partially parallel to each other.

[0065] According to another embodiment of the invention, in order to house the measuring system electronics 2, the measuring system includes an electronics (protective) housing 20, such as explosion-proof (Ex-d) and / or conforming to international standard IEC 60079-1:2014. The mechanical connection between the electronics (protective) housing and the aforementioned wires or containers or with the sensor (protective) housing of the measuring system can be established, for example, by means of a (housing) connection fitting 30 of the measuring system, which itself can be releasably connected to the electronics (protective) housing 20 by means of a flange connection and / or a tubular connection. In this case, the first connecting wire 401, the second connecting wire 402, the third connecting wire 403, and the fourth connecting wire 404 can also be at least partially routed within the (housing) connection fitting 30, for example, such that they extend parallel to each other at least partially within the (housing) connection fitting 30, and / or adjacent connecting wires 401, 402, 403, 404 have at least partially a small distance of less than 5 mm. Especially in the aforementioned cases where the measurement system is housed within the aforementioned electronic device (protective) housing 20 and / or the first, second, third, and fourth connecting lines are at least partially guided within a (housing) connection fitting 30 connected to the same electronic device (protective) housing 20, the measurement system according to another embodiment of the invention further includes at least one (electrical) feedthrough 50, for example, explosion-proof (Ex-d) and / or compliant with international standard IEC 60079-1:2014. Advantageously, the first, second, third, and fourth connecting lines may be routed in portions within the feedthrough 50, and / or the feedthrough 50 may be positioned intermediately between the first connecting line 401, the second connecting line 402, the third connecting line 403, and the fourth connecting line 404. According to another embodiment of the invention, the feedthrough 50 has, for example, unshielded (connection) pins, and the feedthrough 50 is electrically connected to the first connecting line 401, the second connecting line 402, the third connecting line 403, and the fourth connecting line 404 by means of one of the respective (connection) pins.

[0066] For example Figure 2As illustrated in diagram 3, the first sensor element C1 is electrically connected to the measurement system electronics 2 via a first connecting line 401 and a second connecting line 402 (forming the first measurement channel of the measurement system), and the second sensor element R1 is electrically connected to the measurement system electronics 2 via a third connecting line 403 and a fourth connecting line 404 (forming the second measurement channel of the measurement system). For example, if necessary, a (housing) feedthrough 50 is also provided in the middle. Furthermore, the first sensor element C1 of the measurement system according to the invention is specifically designed (in conjunction with the measurement system electronics) to generate and / or set a first electrical (measurement) voltage u1 depending on a first primary (process) measured variable x1, and the measurement system electronics 2 is designed to temporarily detect and evaluate the first electrical (measurement) voltage u1, for example, by digitizing it and / or determining a (digital) first (voltage) measured value Xu1 representing the first (measurement) voltage u1. Especially in the aforementioned case where the measurement system is designed as a vortex flowmeter, the measurement system electronics 2 can also be configured, for example, to determine, at least based on a first electrical (measuring) voltage u1, the frequency (f) of at least temporarily periodic pressure fluctuations within the fluid being measured—particularly the pressure fluctuations within the aforementioned Karman vortex street—(used as a secondary measured variable) V The measured value is obtained by means of at least one measuring capacitor. According to another embodiment of the invention, the first sensor element C1 is designed as a capacitive sensor element (having at least one measuring capacitor). Specifically, the first sensor element C1 has an electrical (sensor) capacitance of not less than 10 pF (picofarad) and / or not greater than 100 pF, particularly at a temperature of 20°C, and / or consists of two or more partial capacitors, and the first sensor element is also configured to follow the change of the first primary (process) measured variable x1 by utilizing a change in the same (sensor) capacitance. Therefore, the first sensor element C1 can also be formed, for example, by means of at least one parallel plate capacitor, particularly having (capacitor) electrode geometry that depends on the change of the first primary measured variable x1 and / or having a dielectric that depends on the change of the first primary measured variable x1. To generate the first electrical (measuring) voltage u1, the measurement system electronics are further configured to at least temporarily charge or maintain a charge on the capacitance of the first sensor element C1; for example, the first electrical (measuring) voltage u1 is also made (substantially) proportional to the charge of the (sensor) capacitance of the first sensor element C1. The second sensor element R1 then has an electrical (sensor) resistance, which, particularly at a temperature of 20°C, is not less than 90 Ω. And / or no more than 1.1k And it is configured to follow the change of the second primary measured variable x2 by utilizing the change in the resistance of the same (sensor). According to another embodiment of the invention, the second sensor element R1 is formed by means of at least one platinum measuring resistor, such as Pt100 and / or Pt1000.

[0067] In the measurement system according to the invention, the measurement system electronics 2 are further configured to temporarily excite the second sensor element R1 so as to temporarily cause a voltage drop across the second sensor element R1, i.e., as well as Figure 4 As shown, during a predetermined first (excitation) time interval t1 lasting for, for example, not less than 100 ms, a driving electrical (measuring) current—particularly an applied and / or constant and / or maximum current having not less than 0.1 mA and / or a maximum electrical power of not less than 0.4 mW in the second sensor element R1—is passed through the second sensor element R1 and the third connection line 403 and the fourth connection line 404. Furthermore, during a second time interval t2 preceding the first time interval t1 and a third time interval t3 following the first (excitation) time interval t1, the second sensor element R1 is not excited, particularly to conserve power or energy, or no (measuring) current is driven through the second sensor element R1 and the third connection line 403 and the fourth connection line 403; this is achieved, in particular, by the fact that the (measuring) current i2, such as Figure 4 As schematically illustrated, at least during a fourth (transition) time interval t4 that follows the second time interval t2 and precedes the first (excitation) time interval t1 and lasts for, for example, not less than 1 µs, a first current edge is exhibited, for example, a current rise rate of at least temporarily and / or (arithmetically) on average of not less than 0.1 mA / µs over time; and the (measured) current i2 exhibits a second current edge that follows the first (excitation) time interval t1 and precedes the third time interval t3 and lasts for, for example, not less than 1 µs over time, a second current edge is exhibited, for example, a current fall rate of at least temporarily and / or (arithmetically) on average of not less than 0.1 mA / µs over time. Furthermore, the measurement system electronics 2 is configured to detect and evaluate a second electrical (measured) voltage u2, which depends on the voltage drop across the second sensor element R1, at least during the first (excitation) time interval t1, for example, by digitizing it and / or determining a (digital) second (voltage) measurement value Xu2 representing the second (measured) voltage u2. Additionally, the measurement system electronics 2 is also configured to determine one or more (digital) measured values ​​of a first primary (process) measured variable x1 and / or one or more (digital) measured values ​​of a secondary (process) measured variable y1, based at least on the first electrical (measured) voltage u1, and for example, also on both the first electrical (measured) voltage u1 and the second electrical (measured) voltage u2, and in particular, to determine them and output them as (qualified) measured values ​​X of the measurement system. MAccording to another embodiment of the invention, the measurement system electronics 2 is further configured to charge or maintain the charge of the capacitor of the first sensor element C1 at least during the second and third time intervals to achieve the first electrical (measured) voltage u1, and / or the measurement system electronics 2 is configured to determine the sensor resistance of the second sensor element R1 based on the second (measured) voltage u2. Advantageously, the measurement system electronics 2 can also be configured to represent the first (measured) voltage u1 (voltage) measured value Xu1, for example, by (temporarily) storing the aforementioned (voltage) measured value u1 in the aforementioned (volatile) digital data storage device and / or using one or more of the same (voltage) measured values ​​to determine one or more measured values ​​of the second primary (process) measured variable x2. Alternatively or additionally, the measurement system electronics 2 may also be configured to determine a (voltage) measured value Xu2 representing the second (measured) voltage u2, for example, so as to (temporarily) store these (voltage) measured values ​​Xu2 in the aforementioned (volatile) digital data storage device and / or use one or more of these (voltage) measured values ​​Xu2 to determine one or more measured values ​​of the first primary (process) measured variable and / or the second primary (process) measured variable x2 and / or the secondary (process) measured variable y1.

[0068] According to another embodiment of the invention, the measurement system electronics 2 is further configured to determine one or more (digital) measured values ​​of the second primary (process) measured variable x2 based on the second electrical (measuring) voltage u2, for example, storing the measured values ​​in the aforementioned (volatile) digital data storage device and / or using them as auxiliary measured values ​​for determining at least one measured value of the secondary and / or first primary (process) measured variables. Alternatively or additionally, the measurement system electronics 2 may also be advantageously configured to use one or more measured values ​​of the second primary (process) measured variable x2 to determine one or more measured values ​​of the first primary (process) measured variable x1. Particularly for the aforementioned case where the measurement system is designed as a vortex flowmeter, the measurement system electronics 2 may, for example, be configured to determine the temperature of the (measured substance) used as the second primary measured variable x2 based at least on the second electrical (measuring) voltage u2 of the (flowing) fluid measured substance. The measured values, and / or the measurement system electronics 2 can be configured to determine the measured values ​​of the volumetric flow rate v (used as a secondary measured variable) and / or the mass flow rate m (used as a secondary measured variable) of the flowing (fluid) analyte and / or the measured value of the (static) pressure p (used as a first primary measured variable x1) of the flowing (fluid) analyte based on a first electrical (measuring) voltage and a second electrical (measuring) voltage.

[0069] To provide the first electrical (measurement) voltage u1, the measurement system electronics 2 according to another embodiment of the invention has at least one operational amplifier OP, such as a FET or CMOS operational amplifier. Furthermore, a first sensor element C1 is electrically connected to the (high-impedance) (voltage) input of the operational amplifier OP via a first connection line 401 and a second connection line 402, specifically forming a charge-to-voltage converter for the measurement system electronics 2, and the operational amplifier is configured to supply the first electrical (measurement) voltage u1 at its (voltage) output (when the measurement system electronics is operating in a first operating mode). For this purpose, the operational amplifier OP may also have, for example, a (feedback) capacitor Cf, whose (voltage) output is connected back to its (voltage) input, particularly a switching capacitor, for example having a (feedback) capacitance of not less than 0.1 pF and / or not greater than 100 pF.

[0070] To provide a second electrical (measuring) voltage u2, the measurement system electronics 2 according to another embodiment of the invention has at least one (electronic) current source, which may also be switchable. Furthermore, the second sensor element R1 is electrically connected to the (current) output of the current source via a third connecting line 403 and a fourth connecting line 404, and the current source is configured to supply the (measuring) current i2, specifically such that the (measuring) current is an applied current or a current regulated to a set point. Instead of the aforementioned current source, the measurement system electronics 2 may also have, for example, at least one (electronic) voltage source VREF, which may also be switchable, which—as well as… Figure 3 The schematic diagram shows an electrical connection via an output and by means of a third connection line 403 and a fourth connection line 404 to the second sensor element R1, configured to drive (measure) current i2 or supply an (applied) voltage to drive (measure) current i2. Alternatively or additionally, the measurement system electronics 2 may also have at least one (reference) resistive element R2, which has a resistance of not less than 1000Ω, especially at a temperature of 20°C. and / or no more than 10k The electrical (reference) resistor is connected to the second sensor element R1, and in particular, is connected in series with the second sensor element R2. Furthermore, the measurement system electronics 2 can be configured to detect and evaluate a third electrical (reference) voltage u3 during the first (excitation) time interval, depending on the voltage drop across the (reference) resistor element R2, particularly by digitizing it and / or determining a (digital) third voltage measurement representing the reference voltage u3. Additionally, the measurement system electronics can be advantageously configured to determine the (sensor) resistance of the second sensor element R1 based on the third (reference) voltage u3, for example, based on the second voltage u2 and the third voltage u3, and the (reference) resistor and / or proportionally.

[0071] Specifically, in the aforementioned case where connecting lines 401, 402, 403, and 404 are at least partially unshielded and the minimum distance between at least one of the first and second connecting lines and at least one of the third and fourth connecting lines is less than 5 mm, at least one of the first connecting lines 401 and the second connecting line 402, and particularly each of them, is coupled to at least one of the third connecting lines 403 and the fourth connecting line 404, and particularly each of them; this is particularly capacitive and / or such that the aforementioned (measured) current i2 or its time variation flowing through the third connecting line 403 and the fourth connecting line 404 can cause (voltage) interference in the first measuring line 401 and the second measuring line 402, and thus cause (voltage) interference in the first electrical (measured) voltage u1. To minimize or avoid any interfering voltage, and particularly any associated measurement error in the measured value determined for the first measured variable x1 caused by such (signal) coupling from the third connection 403 and / or the fourth connection 404 to the first connection 401 and / or the second connection 402, the measurement system electronics 2 of the measurement system according to the invention is further configured not to output (qualified) measured values ​​X for the secondary and / or first primary (process) measured variables determined based on the first (measurement) voltage detected during the fourth (conversion) time interval and the fifth (conversion) time interval. M Alternatively, the measured values ​​for the secondary and / or primary (process) measured variables may not be determined based on the first electrical (measuring) voltage applied during the fourth (transition) time interval and the fifth (transition) time interval. Alternatively or additionally, the measurement system electronics of the measurement system according to the invention may also be configured to determine (qualified) measured values ​​for the secondary and / or primary (process) measured variables during the fourth (transition) time interval based on the first (measuring) voltage u1 previously detected during the second time interval, and / or to determine (qualified) measured values ​​for the secondary and / or primary (process) measured variables during the fifth (transition) time interval based on the first (measuring) voltage u1 previously detected during the first time interval t1. According to another embodiment of the invention, the measurement system electronics 2 are also configured to determine—in particular, determine and output—the (qualified) measured value X of the secondary and / or primary (process) measured variables based on the first (measuring) voltage u1 detected during the (excitation) time interval t1. MAlternatively, if necessary, for example to reduce the electrical power of the conversion and / or to avoid measurement errors, the measurement system electronics 2 may also be configured to output (qualified) measured values ​​of the secondary and / or first primary (process) measured variables x1 not based on the first (measurement) voltage u1 detected during the (excitation) time interval t1 and / or to determine the measured values ​​of the secondary and / or first primary (process) measured variables not based on the first electrical (measurement) voltage u1 applied during the (excitation) time interval. Furthermore, the measurement system electronics 2 may also be advantageously configured to determine one or more (digital) measured values ​​of the second primary (process) measured variable x2 based at least on the second electrical (measurement) voltage u2, particularly based on the second electrical (measurement) voltage u2 determined in the foregoing manner and the first electrical (measurement) voltage u1, and in particular to output them as qualified measured values ​​of the measurement system 2.

[0072] To connect the measurement system to a process that includes or guides the analyte in a leak-free or fluid-tight manner, and particularly to enable the establishment of an effective relationship (leading to measurement results) between the (fluid) analyte and at least a first and a second sensor element during operation of the measurement system, the measurement system according to another embodiment of the invention further includes a (process) coupling element 11, for example, formed by means of a membrane and / or a sleeve and / or a plate. According to another embodiment of the invention, the coupling element is at least partially, for example entirely, made of metal, particularly of (stainless) steel and / or a nickel-based alloy. The coupling element 11 is specifically designed to be in contact (during operation of the measurement system) with the aforementioned analyte, for example, with the substance flowing onto and / or around it; this particularly results in the (process) coupling element 11 having a (coupling element) temperature depending on the temperature of the analyte and / or a (elastic) strain depending on the pressure of the analyte. Accordingly, according to another embodiment, the aforementioned coupling element is also configured to specifically respond to changes in the pressure and strain of the analyte—e.g., biaxial and / or elastic strain—and to changes in the temperature of the analyte and the temperature of the coupling element, for example, such that the temperature of the coupling element deviates from the steady-state temperature of the analyte in steady state by less than 2 K (Kelvin). For example, the coupling element 11 can be arranged to be at least partially inserted into the lumen (3') of the tube (3) (for guiding the fluid analyte), particularly through the tube wall (3') of the closed lumen. The opening (3a) in the tube is inserted into the lumen and (releasably) fixed to the same tube wall. This is especially true in the aforementioned case where the measuring system is designed as a vortex flowmeter. Figure 2The coupling element 11, schematically shown, can be designed as, for example, a sensor fin protruding into the lumen 3' of the aforementioned tube 3. Alternatively, the coupling element 11 can also be arranged, for example, to be at least partially inserted into the lumen of a container (for guiding the fluid analyte), particularly a can, particularly through an opening in the container wall that closes the lumen and is (removably) fixed to the same container wall. In the aforementioned case where the measurement system has a connecting fitting 30, the coupling element 11 can also be arranged, for example, partially within the connecting fitting and / or can be (mechanically) connected to the connecting fitting, for example, at a fitting end remote from the aforementioned electronic housing 20. According to another embodiment of the invention, the coupling element 11 and the first sensor element C1 are at least mechanically coupled to each other, or the first sensor element C1 is designed as an (integrated) component of the coupling element 11; in particular, in each case, such that (during operation of the measurement system) the first electrical (measurement) voltage u1 depends at least on the strain of the coupling element 11, or a change in the strain of the coupling element 11 causes a change in the first electrical (measurement) voltage u1. In the aforementioned case where the first sensor element 11 is formed by means of at least one (measuring) capacitor designed as a parallel plate capacitor, at least one (capacitor) electrode of the (measuring) capacitor—e.g., a movable (capacitor) electrode—can be mechanically connected to or formed by means of the coupling element. According to another advantageous embodiment of the invention, the coupling element 11 and the second sensor element R1 can also be at least thermally coupled to each other, particularly both thermally and mechanically coupled; this makes it particularly likely that the second electrical (measuring) voltage u2 depends at least on the temperature of the coupling element, or that a change in the temperature of the coupling element causes a change in the electrical (sensor) resistance of the second sensor element R1.

Claims

1. A measurement system for measuring a (time-variable) first primary (process) analyte (x1), particularly the (static) pressure of a fluid analyte (carrying in an online manner and / or held in a container) and / or the time-variable change of that pressure, and a (time-variable) second primary (process) analyte (x2), different from the first primary (process) analyte, particularly the temperature of the fluid analyte (carrying in an online manner), and / or for measuring a (time-variable) secondary (process) analyte (y1), particularly the mass flow rate of a fluid analyte carried in an online manner or the fill level of a fluid analyte held in a container, derived from at least one of the first primary (process) analyte and the second primary (process) analyte, said measurement system comprising: - Measurement system electronics (2), particularly operating at a maximum power of less than 1W (watts) and / or connected to a (4-20mA) 2-wire system; - At least one first sensor element (C1), particularly capacitive and / or passive, for detecting the measured variable of the first primary (process). - At least one passive second sensor element (R1), particularly resistive, for detecting the measured variable of the second primary (process); - and the first electrical connection wire, the second electrical connection wire, the third electrical connection wire and the fourth electrical connection wire (401, 402, 403, 404), in particular each of them being (at least) partially unshielded and / or not twisted together; -The first sensor element is electrically connected to the measurement system electronics (2) by means of the first connecting line and the second connecting line (forming the first measurement channel of the measurement system), and in particular by means of the feedthrough (50) placed in the middle. -The second sensor element is electrically connected to the electronic components of the measurement system by means of the third and fourth connecting lines (forming the second measurement channel of the measurement system), particularly by means of a feedthrough (50) placed in the middle. -and wherein at least one of the first connecting line and the second connecting line (401, 402), in particular each, is capacitively (signal) coupled to at least one of the third connecting line and the fourth connecting line (403, 404), in particular each, in particular, by making the minimum distance between at least one of the first connecting line and the second connecting line and at least one of the third connecting line and the fourth connecting line less than 5 mm; - wherein the first sensor element (C1) is configured, in particular, in conjunction with the measurement system electronics, to generate and / or adjust a first electrical (measurement) voltage (u1) depending on the first primary (process) measured variable (x1). -And wherein the second sensor element (R1) has an electrical (sensor) resistance, said electrical (sensor) resistance being not less than 90 ohms, particularly at a temperature of 20°C. (ohms) and / or no more than 1.1k (kiloohms), and is configured to follow the change of the second primary measured variable (x2) with the change of the same resistance; -The measurement system electronics are configured to temporarily record and evaluate the first electrical (measured) voltage (u1), in particular to digitize it and / or determine a (digital) first (voltage) measured value (Xu1) representing the (measured) voltage. - Wherein, the electronic components of the measurement system are configured as --This temporarily causes a voltage drop across the second sensor element to temporarily excite the second sensor element. That is, during a predetermined first (excitation) time interval (t1) lasting at least 10 ms, a driving electrical (measuring) current (i2) is passed through the second sensor element and the third and fourth connecting lines, wherein the current is in particular an applied and / or constant and / or has a maximum current of at least 0.1 mA and / or achieves a maximum electrical power of at least 0.4 mW in the second sensor element. ---And during the second time interval (t2) preceding the first time interval and during the third time interval (t3) following the first (excitation) time interval, the second sensor element is not excited or the (measurement) current is not driven through the second sensor element and the third and fourth connecting lines. ---This causes the (measured) current to exhibit a (rising) first current edge during a fourth (transition) time interval (t4) that follows the second time interval and precedes the first (excitation) time interval and lasts for not less than 1 µs, in particular having a current rise rate that is at least temporarily and / or arithmetically averages at least 0.1 mA / µs over time. ---and such that the (measured) current has a (falling) second current edge during a fifth (transition) time interval (t5) that follows the first (excitation) time interval and precedes the third time interval and lasts, in particular, not less than 1 µs, and in particular has a current fall rate that is at least temporarily and / or arithmetically averages at least 0.1 mA / µs over time. --and wherein the measurement system electronics are configured to detect and evaluate a second electrical (measured) voltage (u2) depending on the voltage drop across the second sensor element during the first (excitation) time interval (t1), in particular to digitize it and / or determine a (digital) second (voltage) measurement (Xu2) representing the (measured) voltage. -The measurement system electronics are configured to determine one or more (digital) measured values ​​of the first primary (process) measured variable (x1) and / or one or more (digital) measured values ​​of the secondary (process) measured variable based at least on the first electrical (measurement) voltage (u1), and in particular on both the first electrical (measurement) voltage and the second electrical (measurement) voltage (u2), and in particular to determine them and output them as qualified measured values ​​(XM) of the measurement system. -And wherein the measurement system electronics are configured, in particular, to avoid measurement errors caused by (signal) coupling from the third and / or the fourth connection line to the first and / or the second connection line in the measured value determined for the first measured variable (x1): --Do not output the (qualified) measured value of the first primary (process) measured variable based on the first (measured) voltage (u1) detected during the fourth (transition) time interval and the fifth (transition) time interval. -- and / or the measured value of the first primary (process) measured variable (x1) is not determined based on the first electrical (measurement) voltage (u1) applied during the fourth (transition) time interval and the fifth (transition) time interval. --and / or do not output the (qualified) measured value of the secondary (process) measured variable (y1) determined based on the first (measured) voltage (u1) detected during the fourth (transition) time interval and the fifth (transition) time interval. --and / or the measured value of the secondary (process) measured variable (y1) is not determined based on the first electrical (measurement) voltage (u1) applied during the fourth (transition) time interval and the fifth (transition) time interval. -- and / or determine the (qualified) measured values ​​(X) of the first primary (process) measured variable (x1) and / or the secondary (process) measured variable (y1) during the fourth (transition) time interval based on the first (measured) voltage previously detected during the second time interval. M ), -- and / or determine the (qualified) measured values ​​(X) of the first primary (process) measured variable and / or the secondary (process) measured variable during the fifth (transition) time interval based on the first (measured) voltage (u1) previously recorded during the first time interval (t1). M ).

2. The measurement system according to claim 1, wherein, The electronic components of the measurement system are configured as follows: --Do not output the (qualified) measured value of the first primary (process) measured variable based on the first (measured) voltage detected during the (excitation) time interval. --and / or the measured value of the first primary (process) measured variable is not determined based on the first electrical (measurement) voltage applied during the (excitation) time interval. --and / or do not output the (qualified) measured value of the secondary (process) measured variable determined based on the first (measured) voltage detected during the (excitation) time interval. -- and / or not based on the first electrical (measurement) voltage applied during the (excitation) time interval to determine the measured value of the secondary (process) measured variable.

3. The measurement system according to claim 1, wherein, The electronic components of the measurement system are configured as follows: --The qualified measured values ​​of the first primary (process) measured variable and / or the secondary (process) measured variable are determined based on the first (measured) voltage detected during the first time interval; -- and / or output the (qualified) measured values ​​of the first primary (process) measured variable and / or the secondary (process) measured variable based on the first (measured) voltage detected during the (excitation) time interval.

4. The measurement system according to any one of the preceding claims, -in, The first sensor element, particularly at a temperature of 20°C, has a capacitance of not less than 10 pF and / or not greater than 100 pF, and is configured to follow changes in the measured variable of the first primary (process) by variations in this same capacitance. -And wherein the measurement system electronics are configured to charge or maintain charge the capacitor of the first sensor element, particularly at least during the second and third time intervals, in order to achieve the first electrical (measurement) voltage.

5. The measurement system according to the preceding claim, wherein, The first electrical (measured) voltage is substantially proportional to the charge of the (sensor) capacitor of the first sensor element.

6. The measurement system according to any one of the preceding claims, wherein, The electronic components of the measurement system are configured to determine the measured values ​​of the voltage representing the first (measured) voltage, and in particular to determine them and store them in a (volatile) digital data storage device.

7. The measurement system according to the preceding claim, wherein, The measurement system electronics are configured to use one or more (voltage) measured values ​​representing the first (measured) voltage to determine one or more measured values ​​of the second primary (process) measured variable.

8. The measurement system according to any one of the preceding claims, wherein, The electronic components of the measurement system are configured to determine the measured values ​​of the voltage representing the second (measured) voltage, and in particular to determine them and store them in a (volatile) digital data storage device.

9. The measurement system according to the preceding claim, -in, The measurement system electronics are configured to determine one or more measured values ​​of the first primary (process) measured variable using one or more (voltage) measured values ​​representing the second (measured) voltage; and / or - wherein the measurement system electronics are configured to determine one or more measured values ​​of the first-stage (process) measured variable using one or more (voltage) measured values ​​representing the second (measurement) voltage; and / or - wherein the measurement system electronics are configured to use one or more (voltage) measured values ​​representing the second (measured) voltage to determine one or more measured values ​​of the second primary (process) measured variable.

10. The measurement system according to any one of the preceding claims, wherein, The measurement system electronics are configured to determine one or more (digital) measured values ​​of the second primary (process) measured variable based on the second electrical (measurement) voltage, in particular determining at least one measured value of the first primary (process) measured variable and / or the secondary (process) measured variable, each measured value serving as an auxiliary measured value, in particular, i.e., determining them and storing them in a (volatile) digital data storage device.

11. The measurement system according to the preceding claim, wherein, The measurement system electronics are configured to determine one or more measured values ​​of the first primary (process) measured variable using one or more measured values ​​of the second primary (process) measured variable.

12. The measurement system according to any one of the preceding claims, wherein, The measurement system electronics are configured to determine one or more (digital) measured values ​​of the second primary (process) measured variable based at least on the second electrical (measurement) voltage, and in particular, based on both the second electrical (measurement) voltage and the first electrical (measurement) voltage, and to determine and output them as qualified measured values ​​of the measurement system.

13. The measurement system according to any one of the preceding claims, -in, Each of the first and second connecting lines is at least partially unshielded, particularly completely unshielded; and / or - wherein each of the third and fourth connecting lines is at least partially unshielded, particularly completely unshielded; and / or - wherein each of the first connecting line and the second connecting line is formed at least partially by means of conductor traces disposed on a (flexible) printed circuit board; and / or - wherein each of the third and fourth connecting lines is formed at least partially by means of conductor traces disposed on a (flexible) printed circuit board; and / or - wherein each of the first connecting line, the second connecting line, the third connecting line, and the fourth connecting line is formed at least partially by means of conductor traces arranged on one and the same (flexible) printed circuit board; and / or - wherein the first connecting line and the second connecting line extend at least partially parallel to each other; and / or - wherein the third connecting line and the fourth connecting line extend at least partially parallel to each other; and / or - wherein the first connecting line and the third connecting line extend at least partially parallel to each other; and / or - wherein the first connecting line and the fourth connecting line extend at least partially parallel to each other; and / or - wherein the first connecting line, the second connecting line, the third connecting line and the fourth connecting line extend at least partially parallel to each other.

14. The measurement system according to any one of the preceding claims, -in, The measurement system electronics have at least one operational amplifier, particularly a FET or CMOS operational amplifier; - wherein the first sensor element is electrically connected to the (high impedance) (voltage) input of the operational amplifier by means of the first connection line and the second connection line, particularly by means of the charge-to-voltage converter forming the measurement system electronics; -And wherein the operational amplifier is configured to supply the first electrical (measured) voltage at the (voltage) output (when the measurement system electronics are operating in the first operating mode).

15. The measurement system according to the preceding claim, wherein, The operational amplifier has, for example, a switchable (feedback) capacitor (Cf), the (voltage) output of which is fed back to its (voltage) input.

16. The measurement system according to the preceding claim, wherein, The (feedback) capacitor (Cf) has a (feedback) capacitance of not less than 0.1pF and / or not greater than 100pF.

17. The measurement system according to any one of claims 1 to 16, -in, The electronic components of the measurement system have at least one (electronic) current source, particularly a switchable (electronic) current source; - wherein the second sensor element is electrically connected to the (current) output of the current source by means of the third and fourth connecting lines; - And wherein the current source is configured to supply the (measured) current.

18. The measurement system according to any one of claims 1 to 16, -in, The electronic components of the measurement system have at least one (electronic) voltage source, particularly a switchable (electronic) voltage source; - wherein the second sensor element is electrically connected to the output of the voltage source by means of the third and fourth connecting lines; -And wherein the voltage source is configured to drive the (measured) current.

19. The measurement system according to any one of the preceding claims, wherein, The measurement system electronics are configured to determine the sensor resistance of the second sensor element based on the second (measured) voltage.

20. The measurement system according to any one of the preceding claims, wherein, The electronic components of the measurement system have at least one (reference) resistive element, which has a resistance of not less than 90 Ω, particularly at a temperature of 20°C. And / or no more than 1.1k The electrical (reference) resistor is electrically connected to the second sensor element, and in particular, is electrically connected in series with the second sensor element.

21. The measurement system according to the preceding claim, wherein, The measurement system electronics are configured to detect and evaluate a third electrical (reference) voltage that depends on the voltage drop across the (reference) resistor element during the first (excitation) time interval, and in particular, to digitize it and / or determine a (digital) third voltage measurement representing the reference voltage.

22. The measurement system according to the preceding claim, wherein, The measurement system electronics are configured to determine the (sensor) resistance of the second sensor element based on the third (reference) voltage, particularly based on the second voltage and the third voltage, and the (reference) resistance and / or proportionally.

23. The measurement system according to any one of the preceding claims further includes at least one (electrical) feedthrough (50), particularly explosion-proof (Ex-d) and / or compliant with international standard IEC 60079-1:2014.

24. The measurement system according to the preceding claim, -in, The first connecting line, the second connecting line, the third connecting line, and the fourth connecting line are partially routed within the feedthrough (50); and / or - wherein the feedthrough, in particular, is electrically connected to the first connection line, the second connection line, the third connection line, and the fourth connection line by means of an unshielded (connection) pin; and / or -The feedthrough is inserted between the first connecting line, the second connecting line, the third connecting line and the fourth connecting line.

25. The measurement system according to any one of the preceding claims further includes an electronic (protective) housing (20) for the electronic components (2) of the measurement system, particularly explosion-proof (Ex-d) and / or conforming to international standard IEC 60079-1:2014.

26. The measuring system according to the preceding claim further includes a (housing) connection fitting (30), which is releasably connected to the electronic (protective) housing, in particular by means of a flange connection and / or in a tubular form.

27. The measurement system according to the preceding claim, wherein, The first connecting line, the second connecting line, the third connecting line and the fourth connecting line are guided at least partially within the (housing) connecting fitting, and in particular extend at least partially parallel to each other.

28. The measurement system according to any one of the preceding claims further includes a (process) coupling element (11), said (process) coupling element (11) being formed, in particular by means of a membrane and / or sleeve and / or plate, said (process) coupling element (11) being contacted (during operation of the measurement system) by a fluid analyte, in particular by said analyte flowing onto and / or around it, in particular such that said (process) coupling element (11) has a (coupling element) temperature depending on the (analyte) temperature and / or such that said (process) coupling element has a (elastic) strain depending on the (analyte) pressure.

29. The measurement system according to the preceding claim, -in, The coupling element is configured to respond to changes in the temperature of the analyte and changes in the temperature of the coupling element, specifically such that the temperature of the coupling element deviates from the steady-state temperature of the analyte by less than 2 K (Kelvin); and / or - wherein the coupling element is configured to respond to changes in the pressure of the analyte using strain, particularly biaxial and / or elastic strain; and / or - wherein the coupling element is designed to be at least partially inserted into the lumen of the tube (for guiding the fluid analyte), particularly through an opening in the tube wall that closes the lumen and to be (releasably) secured to the same tube wall; and / or - wherein the coupling element is designed to be at least partially inserted into the lumen of a container (for guiding the fluid analyte), particularly a can, i.e., inserted into the lumen through an opening in the container wall that closes the lumen and (removably) secured to the same container wall; and / or - wherein the coupling element is at least partially, and in particular entirely, made of metal, especially of (stainless) steel and / or nickel-based alloy.

30. The measurement system according to claim 28 or 29, wherein, The coupling element and the first sensor element are at least mechanically coupled to each other, in particular such that the first electrical (measured) voltage depends on the strain of the coupling element or such that a change in the strain of the coupling element causes a change in the first electrical (measured) voltage.

31. The measurement system according to claim 28 or 29, wherein, The first sensor element is an (integrated) component of the coupling element, specifically such that the first electrical (measured) voltage depends on the strain of the coupling element or such that a change in the strain of the coupling element causes a change in the first electrical (measured) voltage.

32. The measurement system according to claim 26, or in conjunction with any one of claims 28 to 31, -in, The coupling element, particularly at the fitting end remote from the electronic housing, is (mechanically) connected to the connecting fitting; and / or -The coupling element (11) is installed inside the connecting fitting (30).

33. The measurement system according to any one of the preceding claims, wherein, The first sensor element (C1) is formed by means of at least one (measuring) capacitor, particularly designed as a parallel plate capacitor, and particularly having (capacitor) electrode geometry that varies depending on the first primary measured variable and / or having a dielectric that varies depending on the first primary measured variable.

34. The measurement system according to claim 33, in conjunction with any one of claims 28 to 32, wherein, At least one, particularly a movable, electrode of the (measuring) capacitor is mechanically connected to or formed by means of the coupling element.

35. The measurement system according to any one of claims 28 to 33, wherein, The coupling element (11) and the second sensor element (R1) are at least thermally coupled to each other, particularly both thermally and mechanically coupled, such that the second electrical (measured) voltage depends on the temperature of the coupling element or such that changes in the temperature of the coupling element cause changes in the electrical (sensor) resistance of the second sensor element.

36. The measurement system according to any one of the preceding claims, wherein, The second sensor element (R1) is formed by means of at least one platinum measuring resistor, particularly Pt100 and / or Pt1000.

37. The measurement system according to any one of the preceding claims, -in, The measurement system electronics are configured to determine, at least based on the first electrical (measuring) voltage, the measured value of the frequency (used as a secondary measured variable) of at least temporarily periodic pressure fluctuations within the fluid analyte—particularly pressure fluctuations within the Karman vortex street formed in the flow of the analyte; and / or - wherein the measurement system electronics are configured to determine, at least based on the second electrical (measuring) voltage, the measured value of the (substance) temperature, particularly the flowing fluid (substance) as a second primary measured variable; and / or - wherein the electronic components of the measurement system are configured to determine the measured value of the (static) pressure (used as the first primary measured variable) of the (flowing) fluid analyte based on the first electrical (measuring) voltage and the second electrical (measuring) voltage; and / or - Wherein, the measurement system electronics are configured to determine the measured value of the volumetric flow rate of the flowing (fluid) substance (used as a secondary measured variable) based on the first electrical (measuring) voltage and the second electrical (measuring) voltage; and / or -The measurement system electronics are configured to determine the measured value of the mass flow rate (used as a secondary measured variable) of the flowing (fluid) analyte based on the first electrical (measurement) voltage and the second electrical (measurement) voltage.

38. Use of the measurement system according to any one of the preceding claims for measuring a first primary (process) analyte variable, particularly a time-variable (static) pressure, of a fluid analyte (carried online or held in a container), and a second primary (process) analyte variable, particularly a time-variable temperature, which is different from the first analyte variable.

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