Measuring sensor for thermally measuring variables and measuring station comprising such measuring sensor

Abstract

Measurement sensor (1) for determining the temperature of a medium (M) in a container (2), comprising a sensor module and a coupling element (7), the coupling element (7) comprising: a body (8) having a contact surface (9) for contacting the container (2); a cylindrical sensor chamber (10) in the body (8) for the sensor elements (3, 5), where the longitudinal axis of the chamber is at a distance from the contact surfaces equal to at most four radii of the chamber, where the intersection of the normal vectors (N) of the contact surfaces defines a directrix (LK), wherein at the point of intersection of a distance vector (AM) between the directrix and the longitudinal axis (L) of the sensor chamber (10) with the directrix (LK), a direction vector (RV) between the distance vector (AM) and the directrix (LK) spans a reference plane (RE) which is at an angle (alpha) of at least 25 DEG with respect to the longitudinal axis (L) of the sensor chamber; wherein the sensor module comprises: a sensor element located in a sensor chamber; a module base at a distance from the sensor element; the invention relates to a module comprising a module base body, a sensor chamber, a sensor element, and a thermal bridge extending in the sensor chamber between the sensor element and the module base body, the cross-section of the sensor chamber being larger than the cross-section of the thermal bridge along the longitudinal axis of the sensor chamber, the cross-section of the thermal bridge being coplanar with the cross-section of the sensor chamber, respectively, and the cross-section of the thermal bridge being substantially parallel to the cross-section of the sensor chamber. And the thermal bridge body is integrally bonded to the module base body, and wherein the module base body is integrally bonded to a cavity wall of the sensor cavity.

Description

Technical Field

[0001] The invention relates to a measuring sensor for determining a thermal measured variable, in particular for determining the temperature of a medium in a container (eg a tank or a pipeline) or the thermally determined flow rate of a medium. Background Art

[0002] For this purpose, the temperature sensor element needs to be brought into thermal contact with the container, for which purpose a coupling element with a contact surface and a sensor chamber is provided, into which the temperature sensor element is introduced. In particular, so-called thin-film sensors and thick-film sensors as well as so-called thermistors (also called NTC thermistors) are known as temperature sensor elements in the form of resistance elements. In the case of thin-film sensors, in particular resistance temperature detectors (RTDs), for example, sensor elements are used which have connecting wires and are mounted on a carrier substrate, the back of which usually has a metal coating. As temperature sensor elements, so-called resistance elements are also used, for example in the form of platinum elements, which are also marketed under the names PT10, PT100 and PT1000.

[0003] However, in the case of a temperature sensor element in the form of a thermocouple, the temperature is determined by the thermovoltage generated between the single-sided connected hot wires made of different materials. In particular, a thermocouple conforming to DIN standard IEC584, such as a K-type, J-type, N-type, S-type, R-type, B-type, T-type or E-type thermocouple, can be used as a temperature sensor element for temperature measurement.

[0004] The accuracy of temperature measurement is highly dependent on the corresponding thermal contact and the prevailing heat conduction. The heat flow between the medium, the container in which the medium is located, the measuring sensor and the process environment plays a key role here. In order to reliably determine the temperature, it is important that the corresponding temperature sensor and the medium are essentially in thermal equilibrium at least for the period of time required to measure the temperature. The time it takes for the measuring sensor to respond to a temperature change is also called the response time of the measuring sensor.

[0005] In particular, high measuring accuracy can be achieved when the coupling element is immersed in the medium. Therefore, many measuring sensors are known in which the coupling element is in more or less direct contact with the medium. In this way, a good thermal coupling between the medium and the temperature sensor element can be achieved.

[0006] However, for various processes and for many containers, in particular small tanks or small pipelines, non-invasive temperature determination is advantageous. It is also known that there are such measuring sensors whose coupling elements can be fastened from the outside to the container where the medium is located, for example from the measuring sensors known from documents such as DE 10 2014 118 206 A1 or DE 10 2015 113 237 A1. This requires consideration of various additional aspects to ensure good thermal coupling. For example, the mechanical contact and therefore also the thermal contact between the tank and the coupling element is crucial for the measurement accuracy that can be achieved. For example, in the documents US2016 / 0047697A1, DE102005040699B3, EP3230704B1 or EP2038625B1, other different embodiments of measuring sensors for non-invasive temperature measurement are described.

[0007] A central issue for non-invasive temperature determination is the heat dissipation from the process to the environment. This leads to significantly higher measurement errors than if the coupling element were introduced directly into the process. Heat dissipation can also occur via thermal bridges formed by components of the measuring sensor.

[0008] The same problem arises, for example, when measuring flow rates using measuring sensors based on the thermal measuring principle. Such measuring sensors usually comprise at least two sensor elements, of which at least one temperature sensor element and at least one heating element or heatable temperature sensor are present, wherein, in the non-invasive case, a coupling element resting on the pipe wall of the pipeline is used to bring the sensor element into thermal contact with the medium flowing in the pipeline. Summary of the invention

[0009] Based on the problems described for heat dissipation in the context of non-invasive thermal measuring sensors, it is an object of the present invention to provide a measuring sensor with which the non-invasive determination of a thermal measured variable of a medium can be improved.

[0010] According to the invention, this object is achieved by a measuring sensor according to independent claim 1 and a measuring station according to independent claim 14. Advantageous embodiments are subject matter of the dependent claims.

[0011] The measuring sensor according to the invention is used for determining and / or monitoring a thermal process variable (in particular the temperature) or a flow rate determined by thermodynamic methods of a medium in a container by contacting a surface of the container with the aid of a contact surface, the measuring sensor comprising: a coupling element; and Sensor module; Wherein, the connecting element comprises: a body having a contact surface for contacting a surface of a container; wherein the coupling element has an at least partially cylindrical sensor chamber for receiving a sensor element for determining and / or monitoring a process variable; wherein the sensor chamber is at least partially disposed within the body; wherein the distance between the longitudinal axis of the sensor chamber and the contact surface does not exceed four radii of the sensor chamber, such as not more than two radii, in particular not more than one radius; wherein the contact surface has a plurality of normal vectors, the intersection of the plurality of normal vectors defining a guide curve, wherein a minimum distance vector is given between the guide curve and the longitudinal axis of the bore, wherein at the intersection of the distance vector and the guide curve, the distance vector and the direction vector of the guide curve span a reference plane, the angle between the longitudinal axis of the bore and the reference plane being 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 temperature; at least one module base; and at least one thermal bridge; wherein the sensor element is arranged in a first end portion of the sensor chamber, wherein the module base is arranged at a second end portion of the sensor chamber facing away from the first end portion, wherein the thermal bridge extends in the sensor chamber at least through a portion extending between the sensor element and the module base; wherein along a longitudinal axis of the sensor chamber, a cross-section of the sensor chamber is larger than a corresponding coplanar cross-section of the thermal bridge; wherein the thermal bridge is firmly bonded to the module base; Therein, the module base body is firmly bonded to the coupling element in an end portion of the sensor chamber facing away from the sensor element.

[0012] In one embodiment of the present invention, the heat bridge body may include a metal material or a ceramic material.

[0013] Due to the strong bond between the thermal bridge and the module base body and between the module base body and the connecting element, the temperature gradient along the thermal bridge is minimized, and thus the heat dissipation along the thermal bridge is also minimized.

[0014] It is advantageous if the longitudinal axis of the sensor chamber containing the sensor element is aligned at an angle to the guide curve of the contact surface, since this guide curve is flush with the guide curve of the container when the measuring sensor is mounted. As a result, the longitudinal axis of the sensor chamber is also at an angle to the guide curve of the container, which allows a greater distance between the module base and the tank wall of the tank. This makes it easier to manipulate the measuring sensor, in particular if connector couplings or other operating elements are arranged on the module base.

[0015] In a development of the invention, the contact surface has the shape of a section of a lateral cylindrical surface, wherein the guide curve forms the cylinder axis of the lateral cylindrical surface.

[0016] In a development of the invention, the coupling element further comprises a shaft which extends out of the body, wherein the sensor chamber extends through the shaft, wherein the shaft is connected to the body, in particular by means of a press fit or in a firmly bonded manner.

[0017] In a refinement of the invention, the sensor chamber is closed at a first end portion, wherein, starting from the point of the minimum distance from the contact surface to the longitudinal axis of the sensor chamber, the sensor chamber extends in the direction of the end region by no more than eight times the diameter of the sensor chamber at the point of the minimum distance.

[0018] In a development of the invention, the contact surface has an opening to the sensor chamber (10), wherein the sensor element is arranged in the region of the opening relative to the longitudinal axis of the sensor chamber.

[0019] In a development of the invention, the sensor element is fixed with a potting compound, wherein in particular the potting compound closes the opening and preferably the surface contour of the potting compound conforms to the contour of the contact surface (9) in the vicinity of the opening.

[0020] In a development of the invention, the at least one thermal bridge comprises at least two electrical lines connected to the sensor element. The module base comprises an annular body and an electrical insulator, wherein the annular body is particularly a metal annular body, wherein the annular body surrounds the electrical insulator in a firmly bonded manner, wherein the at least two electrical wires are securely bonded to the electrical insulator, and The annular body is firmly bonded to the cavity wall of the sensor cavity.

[0021] In a development of the invention, the at least one thermal bridge 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 firmly bonded to the module base body.

[0022] In one embodiment of the invention, the sleeve is connected to the module base by welding, brazing, bonding and / or casting.

[0023] In one embodiment of this further development of the invention, an electrical line contacting the sensor element is laid in the sleeve and extends from the sensor element to the module base body.

[0024] In a development of the invention, in the region of the contact surface, a unit is arranged which at least partially comprises a material having anisotropic thermal conductivity, preferably a material which at least partially contains carbon, in particular graphite or hexagonal boron nitride, or the body consists of a material having anisotropic thermal conductivity in the region facing the contact surface.

[0025] In a development of the invention, a thermal insulator made of a thermally insulating material is arranged in the area of ​​the body facing away from the contact surface and the sensor chamber, the thermal insulator at least partially surrounding the body, or the body is composed of the thermally insulating material in the area, wherein the thermal conductivity of the thermally insulating material with lower heat dissipation is at most one quarter, in particular at most one eighth, of the thermal conductivity of the material of the body in the area of ​​the contact surface.

[0026] In a development of the invention, the main body is constructed from at least two parts, in particular, the main body is constructed in the form of a layered structure.

[0027] In a refinement of the invention, the measuring sensor comprises a fastening device for fastening the body to the container. For example, the fastening device can be a fastening strap, or a device for producing a clamping screw connection, a screw connection, a spring connection, etc.

[0028] In a development of the invention, the body of the coupling element at least partially consists of a sintered material or a composite material.

[0029] In a refinement of the present invention, the connecting element is designed as a single piece and is in particular manufactured by means of an additive manufacturing process, preferably a 3D printing process, or wherein the connecting element has at least two connecting parts, in particular, the at least two connecting parts are manufactured separately.

[0030] In a refinement of the invention, the measuring sensor comprises at least one component from a list of components comprising: a plug-in connector connection; a field electronic module for driving the sensor element and / or for processing the raw signals of the sensor element, wherein the components are firmly connected to a module base and, in particular, are arranged in the module base.

[0031] The measuring station according to the invention comprises: a measuring sensor according to the invention; and a container for accommodating a medium, the thermal process variable of which is to be determined by means of the measuring sensor, Therein the contact surface rests against a surface portion of the container which is complementary to the contact surface, wherein, in particular, a guide curve of the contact surface coincides with a guide curve of the surface portion.

[0032] In a development of the invention, the container comprises a line section for conducting the medium, wherein the surface section is formed in the line section.

[0033] In one embodiment, the measuring station comprises at least one reference element for in-situ calibration and / or verification of at least the measuring sensor, the reference element being fastened to the outer wall of the container and at least partially consisting of at least one material for which, within a temperature range relevant for the calibration of the measuring sensor, at least one phase transition occurs at at least one specified phase transition temperature, for which phase transition the material remains in the solid state, as described in EP 2 612122 B1.

[0034] In another embodiment, the contact surface is at least partially made of a deformable material, in particular a flexible or ductile material, which is designed so that it can adapt to the contour of the outer wall of the container. Thus, the contact surface can be adapted to the surface of the wall of the container. This has the advantage that the coupling element can compensate for small nominal width differences, shape deviations and / or unevenness of the surface of the corresponding wall of the container.

[0035] In particular, the measuring sensor or measuring station according to the invention can be designed for temperature measurement, but the invention also includes measuring sensors or measuring stations for flow measurement. In this case, the measuring sensor also includes a heating element for heating the medium through the tank wall of the tank, wherein the heating element can be fastened by means of a coupling element. By means of the heating element, the sensor element and the area around the sensor element can be heated to a predeterminable temperature. In the context of the present invention, the term "flow" includes both the volume flow and the mass flow of the medium. Likewise, the flow rate or flow velocity of the medium can also be determined.

[0036] For example, the flow rate can be determined in two different ways. According to a first measuring principle, the sensor element is heated so that its temperature remains essentially constant. In the case of known and at least temporarily constant medium properties (e.g. medium temperature, density or composition of the medium), the mass flow of the medium through the pipeline can be determined from the heating power required to maintain the temperature at a constant value. In this case, the medium temperature refers to the temperature of the medium without any additional heat input from the heating element. In contrast, in the second measuring principle, the heating element is operated with a constant heating power and the temperature of the medium downstream of the heating element is measured. In this case, the measured medium temperature provides information about the mass flow. However, in addition to this, other measuring principles are also known, such as transient methods, in which the heating power or the temperature is modulated.

[0037] For example, the heating element may be designed in the form of a resistance heater which is heated by conversion of the electric power supplied to it, for example as a result of an increase in the electric power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The present invention will be explained in more detail with reference to the following drawings. In the drawings:

[0039] Figure 1 A measuring sensor for non-invasive temperature measurement according to the prior art is shown;

[0040] Figure 2a-2b is a schematic plan view of a one-piece coupling element of a measuring sensor according to the invention on a pipeline;

[0041] Figure 2c-2d is a schematic cross-sectional view of an embodiment of a one-piece coupling element of a measuring sensor according to the invention on a pipeline;

[0042] Figure 2e is a schematic diagram for explaining the geometrical characteristics of a coupling element of a measuring sensor according to the present invention;

[0043] Figure 3 is a schematic diagram of an embodiment of a measuring sensor according to the invention on a pipeline, which has a multi-part coupling element with a fastening device;

[0044] Figure 4 is a schematic diagram of a coupling element of a measuring sensor according to the invention having a thermal insulator;

[0045] Figure 5a-5b A first embodiment of a coupling element of a measuring sensor according to the invention is shown, which is produced in a single piece;

[0046] Figure 6a-6bA second embodiment of a coupling element made in a single piece is shown;

[0047] Figures 7a-7d A detail is shown for mounting a sensor module in a coupling element of a measuring sensor according to the invention. DETAILED DESCRIPTION

[0048] In the figures, identical elements are provided with the same reference numerals. Exemplary embodiments from different figures can also be combined with one another as desired. Furthermore, although all figures relate to a container in the form of a pipeline and a measuring sensor for determining the temperature of a medium, the invention is by no means restricted to pipelines or temperature measurement. On the contrary, the corresponding considerations can easily be applied to other types of containers and measuring sensors.

[0049] Figure 1 is a schematic diagram of a measuring sensor 1 according to the prior art, which has a coupling element 7, a sensor element 10 and an electronic module 4. The measuring sensor 1 serves to detect the temperature T of a medium M located in a container 2, here in the form of a pipeline. For this purpose, the thermometer 1 does not extend into the pipeline 2, but is placed from the outside on the pipe wall W of the pipeline 2 for non-invasive temperature determination.

[0050] The coupling element 7 contains a sensor chamber 10 in which a sensor element 5 is arranged, which sensor element 5 is in the form of a temperature sensor including a resistance element. The sensor element 5 is electrically contacted and connected to the electronic module 4 via connecting wires 6a, 6b. Although the measuring sensor 1 shown has a compact design with an integrated electronic module 4, in other measuring sensors 1, the electronic module 4 can also be arranged in a separate manner from the measuring insert 3. As already explained, the measuring accuracy of such a measuring sensor 1 depends to a large extent on the materials used and the contact means, in particular the thermal contact means, in particular in the area of ​​the temperature sensor. The temperature sensor is in thermal contact with the medium M indirectly, i.e., via the coupling element 7 and via the wall W of the container 2. The heat dissipation of the coupling element 7 to the environment may cause undesirable temperature gradients in the area of ​​the temperature sensor 5, in which case the heat dissipation also plays an important role. In order to appropriately counteract these problems, within the scope of the present invention, an alternative embodiment for non-invasive determination of a process variable by means of a measuring sensor 1 according to the invention is proposed, as shown in Figure 2ff for some exemplary embodiments.

[0051] The measuring sensor 1 according to the invention has a coupling element 7 such as Figures 2a to 2dAs shown. Each coupling element 7 has a body 8, which has a contact surface 9, by means of which the body 8 can be placed flatly and particularly accurately against the wall W of the container 2. Preferably, the contact surface 9 is designed to correspond to the surface O of the wall W of the container 2, for example in the shape of a cylindrical shell. The coupling element 7 also includes a sensor chamber 10, which can be prepared, for example, by a channel in the body 8 and / or in the shaft 8a connected to the body 8, and the position of the sensor chamber 10 is indicated by a dotted line in the figure. The sensor element for temperature measurement by means of the sensor module 3 is introduced into the sensor chamber 10. Details on this aspect are explained further below. The longitudinal axis L of the sensor chamber 10 (which is at least partially cylindrical) is relative to the longitudinal axis L of the container 2. B It's crooked.

[0052] Reference now Figure 2e to explain the alignment of the sensor chamber without involving the container. As previously mentioned, the coupling element 7 comprises a contact surface 9, wherein the longitudinal axis L of the sensor chamber 10 is at a distance d from the contact surface 9, wherein in the illustration, the distance d does not exceed two radii. The contact surface (9) also has a plurality of normal vectors (N), the intersection of which defines a guide curve (LK). For example, if the contact surface has the shape of a cylindrical housing part, the guide curve formed is the associated cylindrical axis. However, Figure 2e The sketch in FIG. 1 shows a generalized situation. A minimum distance vector (AM) is provided between the guide curve (LK) and the longitudinal axis (L) of the sensor chamber (10), wherein at the intersection of the guide curve (LK) and the distance vector (AM), the distance vector (AM) and the direction vector (RV) of the guide curve (LK) extend beyond a reference plane (RE), and the angle (α) between the longitudinal axis (L) of the sensor chamber (10) and the reference plane (RE) is not less than 25°, for example not less than 60°, and in particular not less than 80°.

[0053] On the left side, Figure 2a A first design of a coupling element 7 of a measuring sensor 1 according to the invention is shown, in which the longitudinal axis L of the sensor chamber 10 is K and the longitudinal axis L of the pipeline 2 B The angle α formed between the reference plane and the longitudinal axis L of the sensor chamber 10 is α=90°. In this case, this will also be the angle between the reference plane and the longitudinal axis L of the sensor chamber 10. In contrast, in the case of the coupling element 7 shown on the right side of the figure, α=45°. It is also conceivable that the coupling element 7 has two bores 10a and 10b, each of which is used to receive a sensor module 3a, 3b, such as Figure 2bIn the case of multiple channels 10a and 10b, the corresponding angles α may be the same, such as Figure 2b Alternatively, the corresponding angle α may be different.

[0054] Regarding the design of the body 8, different variants are also conceivable, for example Figure 2c-2d As shown in Figure 2c The embodiment of the invention is a massive body 8, which may bring advantages, in particular, with regard to thermal insulation relative to the environment of the coupling element 7 and the sensor module 3. Moreover, such an embodiment is generally more mechanically robust. Figure 2d In an embodiment of the invention, the coupling element 7 further comprises a shaft 8a, wherein the sensor chamber 10 for receiving the sensor module 3 at least partially extends through the shaft 8a. The shaft 8a has several functions; in particular, the shaft 8a is used to improve the heat conduction from the wall W of the container 2 to the sensor module 3 and to enlarge the area with uniform temperature distribution around the sensor module 3. Furthermore, the shaft 8a can also be used to improve the thermal insulation and / or mechanical stability of the measuring sensor or the sensor module 3 in the sensor chamber 10 of the body 8.

[0055] Figure 3 An embodiment is shown which has a multi-part coupling element 7 and a clamping screw 13 for fastening. The body 8 is designed in two parts and is designed with an axis 8a and has two coupling parts in the form of half shells 11a and 11b and can be arranged around the pipeline 2. The sensor chamber 10 extends in the region of the two half shells 11a and 11b and is closed at the end region 12. It should be pointed out that in other embodiments, the body 8 can also have more than two coupling parts, and even in the case of two coupling parts, these parts do not necessarily have to be designed in the form of half shells 11a and 11b. On the contrary, many different variants can be conceived, all of which fall within the scope of the invention.

[0056] Figure 4 A coupling element 7 is shown with a unit 14, which comprises a material with anisotropic thermal conductivity, and a thermal insulator 15. The unit 14 is arranged in the region of the body 8 facing the container 2, while the thermal insulator 15 is arranged in the region of the body 8 facing away from the container 2 and serves to thermally insulate the coupling element or the measuring station 1 from the environment.

[0057] FIG. 5 illustrates a first possible embodiment of a coupling element 7 manufactured in one piece. The coupling element 7 has a body 8 with an (optional) axis 8 a and a sensor chamber 10 for receiving the sensor module 3. The contact surface 9 lies flat against the wall W of the container 2. The surface of the contact surface 9 is as large as possible, in particular maximized, while the extension of the body 8 perpendicular to the contact surface 9 is as small as possible, in particular minimized. This leads to a particularly compact design. In addition, such an embodiment also ensures that heat losses to the environment are reduced, in particular minimized. This effect can be further increased by taking appropriate measures for the design or structure of the body 8 (for example, with regard to internal heat conduction); in particular, the body 8 can be designed so that the heat conduction from the contact surface 9 to the sensor chamber 10 or to the axis 8 a is increased.

[0058] Although Figure 5a In the case of the main body 8 is a solid body, but Figure 5b The body 8 shown in the figure is a hollow body. The body 8 in the form of a hollow body provides the additional advantage that the sensor element of the sensor module is in direct contact with the wall W of the container 2. This reduces the distance between the sensor element 5 arranged in the measuring insert 3 and the wall W of the container 2 (the measuring insert 3 is arranged tangentially to the wall W of the container 2), which in turn further improves the heat conduction from the medium M to the sensor element 5.

[0059] Finally, FIG. 6 shows an axial embodiment of the body 8 of the coupling element 7. This embodiment constitutes a particularly compact and simple design. It is also conceivable to use a solid ( Figure 6a ) main body 8 and hollow body ( Figure 6b ) body 8 in the form of a one-piece body 8. In addition to the two variants of the one-piece body 8 of Figures 5 and 6, many other possible embodiments of the body 8 of the coupling element 7 according to the invention can also be envisaged, and these embodiments also fall within the scope of the invention. In particular, the embodiments shown in Figures 5 and 6 can also be combined with each other as required.

[0060] In summary, one advantage of the invention is that a non-invasive thermometer 1 can be realized using a standard measuring insert 3, such as a thermometer 1. To this end, the coupling element 7 according to the invention has a sensor chamber 10 for receiving the measuring insert 3. The adaptation to the geometry of the container 2 is achieved by means of the contact surface 9 of the coupling element 7. Compared to other solutions known from the prior art, the longitudinal axis L of the measuring insert 3 is tangential to the wall W of the container, so that an enhanced heat conduction can be achieved.

[0061] Now refer to Figures 7a to 7dTo explain how to arrange the sensor modules 3 of the measuring sensor according to the invention. Each sensor module 3 comprises a module base 20, a sensor element 5 and a thermal bridge 6; 60. The term thermal bridge 6; 60 refers to different functional elements, such as the electrical connection line 6 of the sensor element 5 or a thin-walled metal sleeve 60 in which the sensor element is arranged. From a thermodynamic point of view, the above-mentioned functional elements have a common undesirable property, namely that they dissipate heat when there is a temperature gradient along the longitudinal extension of these functional elements, which is why the general term thermal bridge has been chosen for the functional elements. Figure 7a , 7c As shown in FIGS. 7 and 7d, the sensor element 5 can be arranged in a sensor chamber 10 formed in the body 8 of the coupling element without an additional housing. In this case, the sensor element is located in the region with the smallest distance between the longitudinal axis of the sensor chamber and the contact surface, or the sensor element can be displaced beyond this region in the direction of the closed first end portion of the sensor chamber 10 and further displaced into the sensor chamber.

[0062] The electrical connection line 6 to which the sensor element 5 contacts extends between the sensor element 5 and the rear opening in the second end portion of the sensor chamber 10. In order to minimize temperature gradients, the module base 20 (which has a metallic annular body 22 and a central insulator 24 held therein in a firmly bonded manner) is firmly bonded to the body 8 at the rear opening of the sensor chamber 10, wherein the annular body 22 is bonded to the body 8 via a joint 26. The connection line 6 is routed through the insulator 24 in a firmly bonded manner. Due to this firmly bonded connection, the connection line is thermally coupled to the body 8, so that the temperature gradient along the connection line is minimized. The insulator may include glass, ceramic, or a polymer having sufficient thermal conductivity.

[0063] like Figure 7bAs shown, the sensor element 5 can also be arranged in an encapsulation sleeve 60 in the sensor chamber 10, wherein the sleeve comprises a metal or a ceramic material with high thermal conductivity. The cross-sectional area of ​​the sleeve 60 is smaller than the cross-sectional area of ​​the sensor chamber 10. The connection line 6 for contacting the sensor element 5 extends in the sleeve. Regarding the longitudinal extension of the components of the sensor module 3 in the sensor chamber 10, the explanations for the previously discussed exemplary embodiments apply accordingly. In this case, the sleeve 60 is the main thermal bridge. In order to minimize the temperature gradient along the sleeve 60, the module base 20 (having a metal annular body 22 and a central insulator 24 held by it in a firmly bonded manner) is firmly bonded to the main body 8 at the rear opening of the sensor chamber 10, wherein the annular body 22 is bonded to the main body 8 by a joint 26. The sleeve 60 passes through the insulator 24 in a firmly bonded manner. Due to this firmly bonded connection, the sleeve 60 is thermally coupled to the main body 8, so that the temperature gradient along the connection line is minimized. The insulator can include glass, ceramic or a polymer with sufficient thermal conductivity. As long as the connecting line 6 is routed in the sleeve with a very small cross section, which is much smaller than the cross section of the sensor chamber, the temperature distribution along the connecting line corresponds to the temperature distribution along the sleeve. Therefore, no further measures are required for connecting the connecting line 6 to the module base in a firmly bonded manner. If necessary, the sleeve can be filled with ceramic powder to achieve a uniform temperature control of the connecting line.

[0064] like Figure 7c and 7d As shown, the module base body may also have a connector coupling 28 with connection contacts 30 for connecting power and data lines. If necessary, the module base body 22 may contain a field electronic module for preprocessing and digitizing the raw signal of the sensor element 5.

Claims

1. A measuring sensor (1) for determining a thermal measured variable or a mass flow of a medium (M) in a container (2) by contacting the container (2), in particular, the thermal measured variable is the temperature (T), the measuring sensor (1) comprising: Connecting elements; Sensor module; Wherein, the connecting element comprises: a body (8), the body (8) having a contact surface (9), the contact surface (9) being used to contact the container (2), The coupling element (7) has an at least partially cylindrical sensor chamber (10), the sensor chamber (10) being used to receive a sensor element (3, 5), the sensor element (3, 5) being used to determine and / or monitor a process variable, wherein the sensor chamber (10) is at least partially disposed in the body (8), wherein the distance between the longitudinal axis of the sensor chamber (10) and the contact surface does not exceed four radii of the sensor chamber, for example does not exceed two radii, in particular does not exceed one radius, wherein the contact surface (9) has a plurality of normal vectors (N), the intersection of the plurality of normal vectors (N) defining a guide curve (LK), wherein a minimum distance vector (AM) is given between the guide curve (LK) and the longitudinal axis (L) of the hole (10), wherein at the intersection of the guide curve (LK) and the distance vector (AM), the direction vector (RV) of the guide curve (LK) and the distance vector (AM) cross a reference plane (RE), and the angle (α) between the longitudinal axis (L) of the hole and the reference plane (RE) is not less than 25°, for example not less than 60°, in particular not less than 80°; Wherein, the sensor module comprises: at least one sensor element for detecting temperature; at least one module base; and at least one thermal bridge; wherein the sensor element is arranged in a first end portion of the sensor chamber, wherein the module base is arranged at a second end portion of the sensor chamber facing away from the first end portion, wherein the thermal bridge extends in the sensor chamber at least over a portion extending between the sensor element and the module base body, wherein, along the longitudinal axis of the sensor chamber, a cross section of the sensor chamber is larger than a corresponding coplanar cross section of the thermal bridge, wherein the thermal bridge is firmly bonded to the module base, and The module base is firmly bonded to a cavity wall of the sensor cavity at an end portion of the sensor cavity facing away from the sensor element.

2. The measuring sensor according to claim 1, in, The contact surface (9) has the shape of a portion of a lateral cylindrical surface, and wherein the guide curve forms the cylinder axis of the lateral cylindrical surface.

3. The measuring sensor (100) according to claim 1 or 2, in, The coupling element further comprises a shaft (8a) extending from the body (8), wherein the sensor chamber extends through the shaft (8a), wherein the shaft is connected to the body, in particular by means of a press fit or in a firmly bonded manner.

4. The measuring sensor (100) according to any one of the preceding claims, The sensor chamber (10) is closed at the first end portion (12), wherein, starting from the point of minimum distance from the contact surface to the longitudinal axis of the sensor chamber, the sensor chamber extends in the direction of the end region by no more than eight times the diameter of the sensor chamber at the point of minimum distance.

5. The measuring sensor (100) according to any one of the preceding claims, The contact surface (9) has an opening to the sensor chamber (10), wherein the sensor element is arranged in the region of the opening relative to the longitudinal axis of the sensor chamber.

6. The measuring sensor (100) according to claim 5, The sensor element is fixed with a potting compound, wherein in particular the potting compound fills the opening and preferably the surface contour of the potting compound conforms to the contour of the contact surface (9) in the vicinity of the opening.

7. The measuring sensor (100) according to any one of the preceding claims, wherein the at least one thermal bridge comprises at least two electrical wires connected to the sensor element, The module base comprises an annular body and an electrical insulator, wherein the annular body is particularly a metal annular body. wherein the annular body surrounds the electrical insulator in a firmly bonded manner, wherein the at least two electrical wires are securely bonded to the electrical insulator, and The annular body is firmly bonded to the cavity wall of the sensor cavity.

8. The measuring sensor (100) according to any one of claims 1 to 5, wherein the at least one thermal bridge comprises at least one cylindrical sleeve which is inserted into the sensor chamber, wherein the sensor element is arranged in the sleeve, The sleeve is securely bonded to the module base.

9. The measuring sensor (100) according to any one of the preceding claims, wherein in the region of the contact surface (9) a unit is arranged which at least partially comprises a material having anisotropic thermal conductivity, preferably a material which at least partially contains carbon, in particular graphite or hexagonal boron nitride, or wherein the body (8) in the region facing the contact surface (9) consists of a material having anisotropic thermal conductivity.

10. The measuring sensor (100) according to any of the preceding claims, wherein a thermal insulator (15) made of a thermally insulating material is arranged in a region of the body (8) facing away from the contact surface (9) and the sensor chamber (10), the thermal insulator at least partially surrounding the body (8), or wherein the body (8) consists of the thermally insulating material in the region, wherein The thermal conductivity of the thermally insulating material with a lower heat dissipation is at most one quarter, in particular at most one eighth, of the thermal conductivity of the material of the body in the region of the contact surface.

11. The measuring sensor (100) according to any one of the preceding claims, The main body (8) is constructed from at least two parts, and in particular, the main body (8) is constructed in the form of a layered structure.

12. The measuring sensor (100) according to any of the preceding claims, It comprises a fastening device (13) for fastening the body (8) to the container (2).

13. The measuring sensor (100) according to any one of the preceding claims, The body (8) of the coupling element (7) at least partially comprises a sintered material or a composite material.

14. The measuring sensor (100) according to any one of the preceding claims, wherein the coupling element (7) is designed as a single piece and the coupling element (7) is in particular produced by means of an additive manufacturing process, preferably by means of a 3D printing process, or wherein, The coupling element (7) has at least two coupling parts (11a, 11b), in particular, the at least two coupling parts are manufactured separately.

15. The measuring sensor (100) according to any of the preceding claims, further comprising: at least one component from a list of components comprising: a plug connector coupling; A field electronics module for driving the sensor element and / or for processing the raw signals of the sensor element, wherein the components are firmly connected to the module base and, in particular, are arranged in the module base.

16. Measurement station, including: A measuring sensor (100) according to any one of the preceding claims; a container for accommodating a medium, a process variable of which is to be determined by means of the measuring sensor, wherein the contact surface (9) rests against a surface portion (O) of the container (2) which is complementary to the contact surface (9), In particular, the guide axis of the contact surface coincides with the guide axis of the surface portion. 17 . The measuring station according to claim 16 , wherein the container comprises a pipeline section for conducting the medium, wherein the surface portion (O) is formed in the pipeline section.

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