SENSOR FOR A THERMAL MEASURING QUANTITY AND MEASURING POINT WITH SUCH A SENSOR

Description

[0001] The invention relates to a sensor for determining a thermal measurement quantity, in particular a temperature of a medium or a thermally determined flow rate of the medium in a container, for example a tank or a pipeline.

[0002] For this purpose, a temperature sensor element must be brought into thermal contact with the container. A coupling element with a contact surface and a sensor chamber, into which the temperature sensor element is inserted, is provided for this purpose. Temperature sensor elements in the form of resistance elements include thin-film and thick-film sensors, as well as thermistors (also known as NTC thermistors). In a thin-film sensor, particularly a Resistance Temperature Detector (RTD), for example, a sensor element with connecting wires is applied to a substrate, the back of which is usually coated with metal. Resistance elements, such as platinum elements, are also used as temperature sensor elements and are commercially available under designations such as PT10, PT100, and PT1000.

[0003] In thermocouples, temperature sensors determine the temperature using a thermoelectric voltage generated between thermocouple wires made of different materials connected at one end. For temperature measurement, thermocouples conforming to DIN standard IEC 584, such as type K, J, N, S, R, B, T, or E, can be used.

[0004] The accuracy of temperature measurement is highly dependent on the specific thermal contacts and the prevailing heat conduction. The heat flows between the medium, the container holding the medium, the sensor, and the process environment play a crucial role. For reliable temperature determination, it is essential that the temperature sensor and the medium are essentially in thermal equilibrium for at least a certain period of time required to record the temperature. The time it takes for a sensor to respond to a temperature change is also known as the sensor's response time.

[0005] High measurement accuracy can be achieved particularly when a coupling element is immersed in the medium. Numerous sensors are known in which a coupling element is brought into direct contact with the medium. This allows for good thermal coupling between the medium and the temperature sensor element.

[0006] For various processes and many containers, especially small tanks or pipelines, non-invasive temperature measurement is more advantageous. Sensors are known whose coupling elements can be attached externally to the container holding the medium, for example, from documents such as DE 102014 118 206 A1 or DE 10 2015 113 237 A1. This requires that various additional aspects be considered to ensure good thermal coupling. For example, the mechanical and thus also the thermal contact between the container and the coupling element is crucial for the achievable measurement accuracy. Further different designs of sensors for non-invasive temperature measurement are described, for example, in the documents US2016 / 0047697A1, DE102005040699B3, EP3230704B1, EP2038625B1, EP3124928A2 and CN201413197Y.

[0007] A key problem with non-invasive temperature measurement is heat dissipation from the process to the environment. This results in a significantly higher measurement error than if the coupling element were directly integrated into the process. Heat dissipation can also occur via thermal bridges formed by components of the sensor.

[0008] The same problem arises, for example, in the case of a flow meter based on a thermal measuring principle. Such meters typically comprise at least two sensor elements, with at least one temperature sensor element and at least one heating element or heatable temperature sensor. In the non-invasive case, the sensor elements are brought into thermal contact with a medium flowing in the pipe by means of a coupling element located against a pipe wall.

[0009] Based on the described problem of heat dissipation in non-invasive thermal sensors, the invention aims to provide a sensor with which the non-invasive determination of a thermal measurement quantity of a medium can be improved.

[0010] The problem is solved according to the invention by the measuring sensor according to independent claim 1 and the measuring point according to claim 16.

[0011] Advantageous configurations are the subject of dependent claims.

[0012] The sensor according to the invention for determining and / or monitoring a thermal process parameter, in particular a temperature, or a thermally determined flow rate of a medium in a container, by contacting a surface of the container by means of a contact surface comprises a coupling element; and a sensor module; wherein the coupling element comprises: a base body with a contact surface for contacting the surface of the container, wherein the coupling element has a sensor chamber that is at least partially cylindrical for receiving a sensor element for determining and / or monitoring the process variable, wherein the sensor chamber is arranged at least partially in the base body, wherein a longitudinal axis of the sensor chamber is spaced no more than four radii, for example no more than two radii, in particular no more than one radius of the sensor chamber, from the contact surface, wherein the contact surface has several normal vectors whose intersection points define a guide curve, wherein a minimum distance vector is given between the guide curve and the longitudinal axis of the sensor chamber, wherein the distance vector and a direction vector of the guide curve span a reference plane at the intersection of the guide curve with the distance vector.the longitudinal axis of the sensor chamber has an angle of not less than 20°, for example not less than 60° and in particular not less than 80°; wherein the sensor module comprises: at least one sensor element for detecting a temperature; at least one module base body; and at least one thermal bridge body; wherein the sensor element is arranged in a first end section of the sensor chamber, wherein the module base body is arranged at a second end section of the sensor chamber facing away from the first end section, wherein the at least one thermal bridge body extends in the sensor chamber at least over a section that runs between the sensor element and the module base body, wherein, along the longitudinal axis of the sensor chamber, cross-sections of the sensor chamber are larger than the respective coplanar cross-sections of the at least one thermal bridge body and are smaller than the respective coplanar cross-sections of the sensor chamber.wherein the at least one thermal bridge body is materially bonded to the module base body, and wherein the module base body is materially bonded to the coupling element in an end section of the sensor chamber facing away from the sensor element.

[0013] In one embodiment of the invention, the thermal bridge body can in particular comprise a metallic material or a ceramic material.

[0014] The material-bonded connections between both the thermal bridge body and the module base body, as well as between the module base body and the coupling element, minimize a temperature gradient along the thermal bridge body, thereby minimizing heat dissipation along the thermal bridge body.

[0015] It is advantageous if the longitudinal axis of the sensor chamber containing the sensor element is angled relative to the guide curve of the contact surface, since the guide curve aligns with the guide curve of the container when the sensor is mounted. Thus, the longitudinal axis of the sensor chamber is also angled relative to the guide curve of the container, allowing for a greater distance between the module base and the container wall. This facilitates handling of the sensor, especially when a connector coupling or other operating elements are located on the module base.

[0016] In a further development of the invention, the contact surface has the shape of a section of a cylindrical surface, wherein the guide curve forms a cylinder axis to the cylindrical surface.

[0017] In a further development of the invention, the coupling element further comprises a shaft which extends out of the base body, wherein the sensor chamber runs through the shaft, wherein the shaft is connected to the base body in particular by means of a press fit or by a material bond.

[0018] In a further development of the invention, the sensor chamber is closed in the first end section, wherein the sensor chamber extends from a point of minimum distance of the contact surface to the longitudinal axis of the sensor chamber no more than eight diameters of the sensor chamber at the point of minimum distance in the direction of the end region.

[0019] In a further development of the invention, the contact surface has an opening to the sensor chamber (10), wherein the sensor element is arranged in the area of ​​the opening with respect to the longitudinal axis of the sensor chamber.

[0020] In a further development of the invention, the sensor element is fixed with a potting compound, wherein in particular the potting compound closes the opening and preferably has a surface contour which follows the contour of the contact surface (9) in the vicinity of the opening.

[0021] In a further development of the invention, the at least one thermal bridge body comprises at least two electrical conductors connected to the sensor element, wherein the module base body comprises a ring body, in particular a metallic one, and an electrical insulator body, wherein the ring body surrounds the electrical insulator body in a materially bonded manner, wherein the at least two electrical conductors are materially connected to the electrical insulator body, and wherein the ring body is materially connected to the wall of the sensor chamber.

[0022] In a further development of the invention, the at least one thermal bridge body comprises at least one cylindrical sleeve which is inserted into the sensor chamber, wherein the sensor element is arranged in the sleeve, wherein the sleeve is materially bonded to the module base body.

[0023] In one embodiment of the earth finding system, the sleeve is connected to the module base body by means of welding, soldering, gluing and / or potting.

[0024] In one embodiment of this further development of the invention, electrical conductors are guided in the sleeve, which contact the sensor element and extend from the sensor element to the module base body.

[0025] In a further development of the invention, a unit comprising at least partially a material with anisotropic thermal conductivity is arranged in the area of ​​the contact surface, preferably a material containing at least partially carbon, in particular graphite or hexagonal boron nitride, or the base body consists in an area facing the contact surface of the material with anisotropic thermal conductivity.

[0026] In a further development of the invention, thermal insulation made of a thermally insulating material is arranged in a region of the base body facing away from the contact surface and the sensor chamber, which at least partially surrounds the base body, or wherein the base body in this region consists of the thermally insulating material, wherein the thermally less thermally insulating material has a thermal conductivity that is at least four times lower, in particular at least eight times lower, than that of the material of the base body in the region of the contact surface.

[0027] In a further development of the invention, the base body is composed of at least two components, in particular in the form of a layered structure.

[0028] In a further development of the invention, the measuring sensor comprises fastening means for attaching the base body to the container. For example, the fastening means can include tension bands, or means for creating a clamping connection, a screw connection, a spring connection, or the like.

[0029] In a further development of the invention, the base body of the coupling element comprises at least a portion of a sintered material or a composite material.

[0030] In a further development of the invention, the coupling element is designed in one piece and is manufactured in particular by means of an additive manufacturing process, preferably by means of a 3D printing process, or wherein the coupling element has at least two coupling components, in particular manufactured separately from each other.

[0031] In a further development of the invention, the measuring sensor comprises at least one component from a list of components, which includes: a connector coupling; local electronics for driving the sensor element and / or for processing primary signals of the sensor element, wherein the component is firmly connected to the module base body, and in particular is arranged in the module base body.

[0032] The measuring point according to the invention comprises a sensor according to the invention and a container for holding a medium whose thermal process parameter is to be determined with the sensor, wherein the contact surface is in contact with a surface section of the container that is complementary to it, wherein in particular the guide curve of the contact surface coincides with a guide curve of the surface section.

[0033] In a further development of the invention, the container comprises a pipe section for guiding the medium, wherein the surface section is formed in the pipe section.

[0034] One embodiment includes that the measuring point comprises at least one reference element for in situ calibration and / or validation of at least the sensor, which is attached to the outer wall of the container, and which reference element consists at least partially of at least one material for which, in the temperature range relevant for the calibration of the sensor, at least one phase transition occurs at at least one predetermined phase transition temperature, for which phase transition the material remains in the solid phase, as described in EP 2 612 122 B1.

[0035] Another embodiment involves the contact surface being made at least partially of a deformable, in particular flexible or ductile, material, which is designed to conform to the contour of the outer wall of the container. The contact surface can thus be adapted to the surface of the container wall. This has the advantage that minor differences in nominal diameter, deviations in shape, and / or surface irregularities of the respective container wall can be compensated for by the coupling element.

[0036] The sensors or measuring points according to the invention can be configured in particular for temperature measurement; however, the invention also includes sensors or measuring points for flow measurement. In this case, the sensor also includes a heating element, which is used to heat the medium through a container wall, and which can be attached by means of a coupling element. By means of the heating element, the sensor element and a region surrounding the sensor element can be heated to a predefinable temperature. Within the scope of the present invention, the term flow rate includes both volumetric flow rate and mass flow rate of the medium. Likewise, a flow velocity or flow rate of the medium can be determined.

[0037] For example, flow rate can be determined in two different ways. According to the first measuring principle, a sensor element is heated in such a way that its temperature remains essentially constant. Given known and at least temporarily constant medium properties, such as the medium temperature, density, or composition, the mass flow rate of the medium through the pipeline can be determined based on the heating power required to maintain the temperature at this constant value. The medium temperature is defined here as the temperature the medium would have without any additional heat input from a heating element. In the second measuring principle, the heating element is operated at a constant heating power, and the temperature of the medium downstream of the heating element is measured. In this case, the measured temperature of the medium provides information about the mass flow rate.In addition, other measurement principles have also become known, for example so-called transient methods in which the heating power or the temperature is modulated.

[0038] The heating element can, for example, be designed in the form of a resistance heater, which is heated by converting electrical power supplied to it, e.g. as a result of an increased current supply.

[0039] The invention is explained in more detail using the following figures. They show: Fig. 1 : a state-of-the-art non-invasive temperature measurement sensor; Fign. 2a-b : Schematic top views of embodiments of one-piece coupling elements of measuring sensors according to the invention on a pipeline; Figs. 3c-d: Schematic cross-sections of embodiments of one-piece coupling elements of measuring sensors according to the invention on a pipeline; Fig. 2e : a sketch to illustrate geometric properties of coupling elements of the measuring sensors according to the invention; and Fig. 3 : a schematic representation of an embodiment of a measuring sensor according to the invention with a multi-part coupling element with fastening means on a pipeline; Fig. 4 : a schematic representation of a coupling element of a sensor according to the invention with thermal insulation; Fign. 5a-b : a first embodiment of a coupling element manufactured in one piece for a measuring sensor according to the invention; Fign. 6a-b : a second embodiment of a one-piece manufactured coupling element; and Fign. 7a-d Details regarding the mounting of the sensor module in a coupling element of a measuring transducer according to the invention.

[0040] In the figures, identical elements are each designated with the same reference numeral. Furthermore, the embodiments from the various figures can be combined with one another as desired. Although all figures relate to containers in the form of pipelines and sensors for determining a medium temperature, the present invention is by no means limited to pipelines or temperature measurement. Rather, the respective considerations can readily be transferred to other types of containers and sensors.

[0041] In Fig.1 Figure 1 shows a schematic diagram of a measuring device 1 according to the prior art, comprising a coupling element 7, a sensor element 10, and electronics 4. The measuring device 1 serves to detect the temperature T of a medium M, which is located in a container 2, here in the form of a pipeline. For this purpose, the thermometer 1 does not protrude into the pipeline 2, but rather is attached to a wall W of the pipeline 2 from the outside for non-invasive temperature determination.

[0042] The coupling element 7 contains a sensor chamber 10 in which the sensor element 5, in the form of a temperature sensor comprising a resistance element, is arranged. The sensor element 5 is electrically contacted via the connecting leads 6a, 6b and connected to the electronics 4. While the sensor 1 shown is designed in a compact form with integrated electronics 4, in other sensors 1 the electronics 4 can also be arranged separately from the measuring element 3. As already explained, the measuring accuracy of such a sensor 1 depends to a large extent on the materials used and on the respective, especially thermal, contacts, particularly in the area of ​​the temperature sensor. The temperature sensor is in indirect thermal contact with the medium M, i.e., via the coupling element 7 and the wall W of the container 2.In this context, heat dissipation from the coupling element 7 to the environment also plays a significant role, as it can lead to an undesirable temperature gradient in the area of ​​the temperature sensor 5. To adequately address these problems, the present invention proposes an alternative embodiment for the non-invasive determination of a process parameter using the sensor 1 according to the invention, as shown in the drawings. Fign. 2 The following are examples of some exemplary designs.

[0043] The measuring sensors 1 according to the invention have coupling elements 7, as shown in Fig. 2a bis 2d As shown, a coupling element 7 has a base body 8 with a contact surface 9, by means of which the base body 8 can be applied to a wall W of a container 2 in a planar and, in particular, precisely fitting manner. The contact surface 9 is preferably designed to correspond to a surface of the wall W of the container 2, for example, in a cylindrical shell shape. The coupling element 7 also has a sensor chamber 10, which can be provided, for example, by a bore in the base body 8 and / or in a shaft 8a connected to it, and whose position is indicated in the drawings by a dashed line. A sensor element for temperature measurement by means of a sensor module 3 is inserted into the sensor chamber 10. Details are explained in more detail below. A longitudinal axis L of the at least partially cylindrical sensor chamber 10 is skew to a longitudinal axis LB of the container 2.

[0044] The alignment of the sensor chamber without reference to the container is now done with reference to Fig. 2e explained. As mentioned, the coupling element 7 comprises a contact surface 9, wherein a longitudinal axis L of the sensor chamber 10 has a distance d to the contact surface 9, where the distance d in the illustration is no more than two radii. The contact surface (9) also has several normal vectors (N) whose intersection points define a guide curve (LK). If the contact surface has, for example, the shape of a cylindrical shell segment, the resulting guide curve is the corresponding cylinder axis. In the sketch in Fig. 2e However, a generalized case is presented. A minimum distance vector (AM) is given between the guide curve (LK) and the longitudinal axis (L) of the sensor chamber (10), wherein the distance vector (AM) and a direction vector (RV) of the guide curve (LK) span a reference plane (RE) at the intersection of the guide curve (LK) with the distance vector (AM), to which the longitudinal axis (L) of the sensor chamber (10) has an angle (α) of not less than 25°, for example not less than 60° and in particular not less than 80°.

[0045] In Fig. 2a On the left, a first embodiment of a coupling element 7 of a sensor 1 according to the invention is shown, in which an angle α between the longitudinal axis LK of the sensor chamber 10 and a longitudinal axis LB of the pipe 2 is α = 90°. This would also be the angle between the reference plane and the longitudinal axis L of the sensor chamber 10. In contrast, in the coupling element 7 shown on the right, α = 45°. It is also conceivable that the coupling element 7 has two bores 10a and 10b, each of which serves to receive a sensor module 3a, 3b, as shown in Fig. 2b illustrated. In the case of multiple boreholes 10a and 10b, the respective angles α can each be the same, as in the case of the Fig. 2b , or different.

[0046] Various options are conceivable for the design of the basic body 8, as shown for example in the drawings. Fig. 2c-d outlined. In the design according to Fig. 2c This is a solid base body 8, which can offer particular advantages with regard to thermal insulation from the environment of the coupling element 7 and sensor module 3. Furthermore, such a design is typically more mechanically robust. In the design according to Fig. 2d The coupling element 7 additionally comprises a shaft 8a, wherein the sensor chamber 10 for receiving the sensor module 3 extends at least partially through the shaft 8a. The shaft 8a has various functions; in particular, it serves to improve heat conduction from the wall W of the container 2 to the sensor module 3 and to increase the area with a homogeneous temperature distribution around the sensor module 3. Furthermore, the shaft 8a can serve to improve the thermal insulation and / or the mechanical stability of the sensor or the sensor module 3 in the sensor chamber 10 of the base body 8.

[0047] In Fig. 3 An embodiment is sketched with a multi-part coupling element 7 and clamping screws 13 for fastening. The base body 8 is designed in two parts with a shaft 8a and has two coupling components in the form of half-shells 11a and 11b, which are arranged around a pipe 2. The sensor chamber 10 extends in the area of ​​both half-shells 11a and 11b and is closed at an end 12. It should be noted that the base body 8 can also have more than two coupling components in other embodiments, and that even in the case of two coupling components, these do not necessarily have to be designed in the form of half-shells 11a and 11b. Rather, numerous different variants are conceivable, all of which fall within the scope of the present invention.

[0048] In Fig. 4 A coupling element 7 is shown with a unit 14 comprising a material with anisotropic thermal conductivity and a thermal insulation 15. The unit 14 is arranged in a region of the base body 8 facing the container 2, while the thermal insulation 15 is arranged in a region of the base body facing away from the container 2 and serves to insulate the coupling element or the measuring point 1 from its surroundings.

[0049] A first possible embodiment for a one-piece manufactured coupling element 7 is shown in Fig. 5 The coupling element 7 has a base body 8 with an (optional) shaft 8a and a sensor chamber 10 for receiving a sensor module 3. The contact surface 9 lies flat against the wall W of the container 2. The surface area of ​​the contact surface 9 is as large as possible, in particular maximized, while the extension of the base body 8 perpendicular to the contact surface 9 is particularly small, in particular minimal. This results in a particularly compact design. Furthermore, this design also ensures reduced, in particular minimized, heat loss to the environment. This effect can be further enhanced by suitable measures regarding the design or construction of the base body 8, for example, with regard to internal heat conduction. In particular, the base body 8 can be designed such that increased heat conduction occurs from the contact surface 9 to the sensor chamber 10 or to the shaft 8a.

[0050] While in the case of the Fig. 5a Since the basic body 8 is a solid body, the one in Fig. 5b The depicted base body 8 surrounds a hollow body. A base body 8 in the form of a hollow body offers the additional advantage that a sensor element of a sensor module comes into direct contact with the wall W of the container 2. This reduces the distance between the sensor element 5, which is arranged in the measuring insert 3, and the wall W of the container 2, to which the measuring insert 3 is tangentially arranged, which in turn results in a further improvement in heat conduction from the medium M to the sensor element 5.

[0051] In Fig. 6 Finally, a shaft-like design of the base body 8 of the coupling element 7 is shown. This design represents a particularly compact and simple construction. For this design as well, it is conceivable to use a solid ( Fig. 6a ) Basic body 8 as well as a basic body in the form of a hollow body ( Fig. 6b ) to use. In addition to the two variants for a one-piece base body 8 made of Fig. 5 und 6 Numerous other possible embodiments for a base body 8 of a coupling element 7 according to the invention are conceivable, which also fall within the scope of the present invention. In particular, those shown in the figures Fig. 5 und Fig. 6 The designs shown can also be combined with each other as desired.

[0052] In summary, an advantage of the present invention is that a standard measuring insert 3, for example from a thermometer 1, can be used to implement a non-invasive thermometer 1. For this purpose, the coupling element 7 according to the invention has a sensor chamber 10 for receiving the measuring insert 3. Adaptation to the geometry of the container 2 is achieved by means of the contact surface 9 of the coupling element 7. In contrast to other solutions known from the prior art, a longitudinal axis L of the measuring insert 3 runs tangentially to the wall of the container W, thereby achieving improved heat conduction.

[0053] Based on the Fign 7a bis d It will now be explained how the sensor modules 3 of the measuring transducers according to the invention are to be arranged. The sensor modules 3 each comprise a module base body 3, a sensor element 5, and a thermal bridge body 6; 60. The term thermal bridge body 6; 60 refers to functional elements as diverse as electrical connecting leads 6 of the sensor element 5 or a thin-walled metallic sleeve 60 in which the sensor element is arranged. From a thermal perspective, the aforementioned functional elements have the common undesirable property that they can dissipate heat along their longitudinal extent in the presence of temperature gradients, which is why the collective term thermal bridge body has been chosen for them. As in Fign. 7a, 7c und 7d The sensor element 5 can be arranged without further encasing in the sensor chamber 10, which is formed in the base body 8 of the coupling element. In this case, the sensor element is located in the area of ​​minimal distance between the longitudinal axis of the sensor chamber and the contact surface, or the sensor element can be displaced further into the sensor chamber beyond this area in the direction of a closed first end section of the sensor chamber 10.

[0054] Electrical connecting leads 6, which contact the sensor element 5, run between the sensor element 5 and a rear opening in a second end section of the sensor chamber 10. To minimize a temperature gradient, the module base body 3, which has a metallic ring body 22 and a central insulator body 24 held by it in a metallurgical bond, is metallurgically connected to the base body 8 at the rear opening of the sensor chamber 10, with the ring body 22 being joined to the base body 8 by a joint 26. The connecting leads 6 are metallurgically guided through the insulator body 24. This metallurgical connection thermally couples the connecting leads to the base body 8 to such an extent that a temperature gradient along the connecting leads is minimized. The insulator body can comprise glass, ceramic, or a polymer with sufficient thermal conductivity.

[0055] As in Fign. 7b The sensor element 5 can also be arranged in a sheathing sleeve 60 within the sensor chamber 10, the sleeve being made of a metallic or ceramic material with high thermal conductivity. The sleeve 60 has a smaller cross-sectional area than the sensor chamber 10. Connecting leads 6 for contacting the sensor element 5 run inside the sleeve. Regarding the longitudinal extent of the components of the sensor module 3 within the sensor chamber 10, the explanations for the previously discussed embodiments apply accordingly. In this case, the sleeve 60 is the dominant thermal bridge element.To minimize a temperature gradient along the sleeve 60, the module base body 3, which comprises a metallic ring body 22 and a central insulator body 24 held by it in a metallurgical bond, is metallurgically connected to the base body 8 at the rear opening of the sensor chamber 10, the ring body 22 being joined to the base body 8 by a joint 26. The sleeve 60 is metallurgically guided through the insulator body 24. This metallurgical connection thermally couples the sleeve 60 to the base body 8 to such an extent that a temperature gradient along the connecting leads is minimized. The insulator body can comprise glass, ceramic, or a polymer with sufficient thermal conductivity.Since the connecting wires 6 are guided within the sleeve in a very small cross-section, significantly smaller than the cross-section of the sensor chamber, the temperature distribution along the connecting wires corresponds to the temperature distribution along the sleeve. Therefore, no further measures are required for the metallurgical coupling of the connecting wires 6 to the module base body 3. Optionally, the sleeve can be filled with a ceramic powder to ensure uniform temperature distribution of the connecting wires.

[0056] As in Fign. 7c und 7d The module base body can also be shown to have a connector coupling 28 with connection contacts 30 for connecting a power supply and data line. Optionally, the module base body 3 can contain local electronics for preprocessing and digitizing primary signals from the sensor element 5.

Claims

1. A measuring transducer (1) for determining a thermal measured variable, in particular a temperature (T), or a mass flow rate of a medium (M) in a container (2) with contacting of the container (2), comprising A coupling element; and a sensor module (3); wherein the coupling element (7) comprises: A basic body (8) with a contact surface (9) for contacting the container (2), wherein the coupling element (7) has a sensor chamber (10), which is cylindrical at least in sections, for mounting a sensor element (5) for determining and / or monitoring the process variable, wherein the sensor chamber (10) is arranged in the basic body (8) at least in sections, wherein a longitudinal axis of the sensor chamber (10) is positioned at a distance from the contact surface, which is equal to no more than four radii, for example no more than two radii, in particular no more than one radius of the sensor chamber (10), wherein the contact surface (9) has several normal vectors (N) whose points of intersection define a directrix (LK), wherein a minimum distance vector (AM) is present between the directrix (LK) and the longitudinal axis (L) of the sensor chamber (10), wherein the distance vector (AM) and a direction vector (RV) of the directrix (LK) create a reference plane (RE) at the point where the directrix (LK) intersects the distance vector (AM), relative to which the longitudinal axis (L) of the sensor chamber (10) has an angle (α) of no less than 25°, for example no less than 60° and in particular no less than 80°; wherein the sensor module (3) comprises: At least one sensor element (5) for detecting a temperature of at least one module basic body (3); and at least one thermal bridge body (6); wherein the sensor element (5) is arranged in a first end section of the sensor chamber (10), wherein the module basic body (3) is arranged at a second end section of the sensor chamber (10) facing away from the first end section, wherein the at least one thermal bridge body (6) extends in the sensor chamber (10) at least over one section which runs between the sensor element (5) and the module basic body (3), wherein cross-sections of the sensor chamber (10) along the longitudinal axis of the sensor chamber (10) are larger than the respective coplanar cross-sections of the at least one thermal bridge body (6); wherein the at least one thermal bridge body (6) is connected to the module basic body (3) by means of a permanent material bond, and wherein the module basic body (3) is connected to the wall of the sensor chamber (10) by means of a permanent material bond in an end section of the sensor chamber (10) facing away from the sensor element (5).

2. The measuring transducer (1) as claimed in claim 1, wherein the contact surface (9) has the shape of a section of a cylindrical lateral surface, and wherein the directrix forms a cylinder axis relative to the cylindrical lateral surface.

3. The measuring transducer as claimed in claim 1 or 2, wherein the coupling element (7) also has a shaft (8a) which protrudes from the basic body (8), wherein the sensor chamber (10) extends through the shaft (8a), wherein the shaft (8a) is connected to the basic body (8), in particular by means of a press fit or a permanent material bond.

4. The measuring transducer as claimed in at least one of the preceding claims, wherein the sensor chamber (10) is closed at the first end section (12), wherein, from a point where the contact surface is closest to the longitudinal axis of the sensor chamber (10), the sensor chamber (10) extends no more than eight times the diameter of the sensor chamber (10) toward the end section at the closest point.

5. The measuring transducer (1) as claimed in at least one of the preceding claims, wherein the contact surface (9) has an opening toward the sensor chamber (10), wherein the sensor element (5) is arranged in the area of the opening relative to the longitudinal axis of the sensor chamber (10).

6. The measuring transducer (1) as claimed in claim 5, wherein the sensor element (5) is secured in place with a compound, wherein, in particular, the compound fills the opening and preferably has a surface contour which follows the contour of the contact surface (9) around the opening.

7. The measuring transducer (1) as claimed in at least one of the preceding claims, wherein the at least one thermal bridge body (6) comprises at least two electrical lines which are connected to the sensor element (5), wherein the module basic body (3) comprises an in particular metal annular body (22) and an insulator body (24), wherein the annular body (22) surrounds the insulator body (24), creating a permanent material bond, wherein the at least two electrical lines are connected to the insulator body (24) by means of a permanent material body, and wherein the annular body (22) is connected to the wall of the sensor chamber (10) by means of a permanent material bond.

8. The measuring transducer (1) as claimed in at least one of claims 1 to 5, wherein the at least one thermal bridge body (6) comprises at least one cylindrical sleeve (60) which is inserted into the sensor chamber (10), wherein the sensor element (5) is arranged in the sleeve (60), wherein the sleeve (60) is connected to the module basic body (3) by means of a permanent material bond.

9. The measuring transducer (1) as claimed in at least one of the preceding claims, wherein a unit (14) comprised at least partially of a material with anisotropic thermal conductivity, preferably a material at least partially containing carbon, in particular graphite or hexagonal boron nitride, is arranged in the area of the contact surface (9), or wherein the basic body (8) consists of the material with anisotropic thermal conductivity in an area facing toward the contact surface (9).

10. The measuring transducer (1) as claimed in at least one of the preceding claims, wherein thermal insulation (15) consisting of a thermally insulating material is arranged in an area of the basic body (8) facing away from the contact surface (9) and the sensor chamber (10), which at least partially surrounds the basic body (8), or wherein the basic body (8) consists of the thermally insulating material in this area, wherein the less thermally insulating material has a thermal conductivity which is lower than that of the material of the basic body (8) in the area of the contact surface by at least a factor of four, in particular by at least a factor of eight.

11. The measuring transducer (1) as claimed in at least one of the preceding claims, wherein the basic body (8) is constructed from at least two components, in particular in the form of a layered structure.

12. The measuring transducer (1) as claimed in at least one of the preceding claims, comprising mounting materials (13) for mounting the basic body (8) on the container (2).

13. The measuring transducer (1) as claimed in at least one of the preceding claims, wherein the basic body (8) of the coupling element (7) contains a sintered material or a composite material, at least partially.

14. The measuring transducer (1) as claimed in one of the preceding claims, wherein the coupling element (7) is designed as a single part and, in particular, is produced by means of a generative manufacturing process, preferably by means of a 3D printing process, or wherein the coupling element (7) has at least two coupling components (11a, 11b), in particular ones which are produced separately from each other.

15. The measuring transducer (1) as claimed in one of the preceding claims, further comprising: At least one component from a list of components, which comprises: A plug connector coupling; On-site electronics for driving the sensor element (5) and / or for preparing primary signals from the sensor element (5), wherein the component is permanently connected to the module basic body (3), and in particular is arranged in the module basic body (3).

16. A measuring point, comprising: A measuring transducer (1) as claimed in one of the preceding claims and container (2) for housing a medium (M) whose process variable is to be determined using the measuring transducer (100), wherein the contact surface (9) rests on a surface section (O) of the container (2) which is complementary to it, wherein, in particular, the master axis of the contact surface (9) coincides with a master axis of the surface section.

17. The measuring point as claimed in claim 16, wherein the container (2) comprises a pipeline section for conducting the medium (M), wherein the surface section (O) is formed in the pipeline section.