Sensor for process measurement technology, measuring arrangement, process plant and method for operating a sensor

Abstract

Sensor (1) for process measurement technology for measuring a physical and / or chemical process parameter of a process medium (M) located in a container (2), wherein the sensor (1) comprises a level sensor or a limit level sensor, with a detector (3), a process connection (4), sensor electronics (5) and a housing (6), wherein the sensor electronics (5) are arranged in the housing (6), wherein the sensor (1) comprises a heat exchanger (7), wherein the heat exchanger (7) is designed to be load-bearing, i.e., to absorb mechanical sensor holding forces, wherein a) the heat exchanger (7) is arranged at the process connection (4).at least also formed by the process connection (4) and / or b) the sensor (1) has a sensor neck (8) and the heat exchanger (7) is formed by the sensor neck (8) or a region of the sensor neck (8), wherein c) the heat exchanger (7) has at least one, for example, spiral and / or meandering fluid channel (10), and the fluid channel (10) has a heat transfer medium connection (11), wherein the heat exchanger (7) is additively manufactured so that it can have very complex geometries optimized with respect to heat conduction.

Description

The invention relates to a sensor according to the preamble of claim 1, a measuring arrangement according to the preamble of claim 10, a process plant according to the preamble of claim 11 and a method for operating a sensor according to the preamble of claim 12.The invention relates to a fill level sensor by means of which fill levels of fill substance can be measured, for example in a container. The fill level in the container is determined in particular continuously. The invention also relates to a limit level sensor. By means of this, the fill level is not determined continuously, but rather the reaching of a predefined fill level, the so-called limit level, is detected. The limit level sensor can be designed as a limit level switch. The term "fill level" refers in particular to a fill level in the context of this publication. The filling material can be, for example, liquids, pastes, powders or coarse bulk materials.Sensors for process measurement technology have in common that they must be mounted in such a way that they can measure the process variable of the process medium to be measured and, in particular, a detector of the sensor is arranged in the vicinity of the process medium or can even touch it.Prior art is shown by CN 2 10 268 993 U, EP 3 158 306 B1, DE 82 16 324 U1, DE 10 2018 129 357 A1, DE 10 2004 023 744 A1, DE 10 2020 120 593 A1, CN 1 13 310 621 A, CN 1 13 701 852 A, DE 10 2014 107 781 A1, DE 10 2009 028 620 A1, DE 10 2012 105 281 A1, DE 10 2015 121 462 A1, DE 197 81 052 T5, DE 21 51 226 A, CN 2 10 603 497 U, CN 2 08 171 512 U, CN 2 08 026 419 U, CN 1 12 284 604 A, CN 1 04 272 075 A, CN 2 08 000 174 U, CN 2 12 779 725 U, Germany, cn 1 12 378 572 a and US 2013 / 0 005 372 A1.The disadvantage of known sensors is that their temperature application range, based on the temperature of the process medium and / or the process environment, is limited, that their space requirement is large, or that they are complicated to produce and / or operate.It is therefore the object of the present invention to provide a further developed sensor.This object is achieved by a sensor having the features of claim 1, a measuring arrangement having the features of claim 10, a process plant having the features of claim 11, and a method for operating a sensor having the features of claim 12.Advantageous embodiment variants of the invention are evident from the dependent claims and the following description. The features listed in the claims and dependent claims can be combined, even beyond category limits, in any desired, technically meaningful manner both with one another and with the features explained in more detail in the following description and represent other advantageous embodiment variants of the invention. For example, features explained in connection with the sensor can also be combined with features of the measuring arrangement or of the method and vice versa.A sensor according to the invention for process measurement technology for measuring a physical and / or chemical process variable of a process medium located in a container has a detector, a process connection, sensor electronics and a housing. The sensor electronics are arranged in the housing. The sensor comprises a heat exchanger.In this way, the temperature application range of the sensor may be extended without excessive increase in manufacturing and / or operating complexity or space requirements.The heat exchanger serves in particular for protecting the sensor electronics from overtemperature. In a particularly advantageous embodiment variant, the main purpose of the heat exchanger is here or the heat exchanger is optimized with respect to fulfilment of this purpose.The physical process variable can be the fill level or limit level.Within the scope of this publication, the term process connection refers to the part or element of the sensor with which it can be arranged in a process environment, e.g. on a container. The process connection thus represents the mechanical interface between the sensor and a process environment. The fact that the sensor has a process connection means, in particular, that the housing can be connected to a process environment. The process connection preferably interacts with a housing region of the sensor. The process connection can be formed integrally with a housing region of the sensor. The process connection can be connected to a housing region of the sensor. The process connection can be manufactured from a material selected in a suitable manner for the process environment, for example mechanically and chemically resistant, for example a suitably alloyed steel, plastic, glass or ceramic. The process connection can comprise a process connection external thread or be formed thereby. The process connection can comprise a union nut or be formed thereby, which can interact with a thread or projection of the housing of the sensor. The process connection can comprise a so-called clamp connection, i.e. an adapter for adapting a sensor region to a receptacle of the process environment, or can be formed as a result. The adapter can comprise an inner region, e.g. threaded region, for fastening the sensor region, in particular region of the housing, and an outer region, e.g. clamping region, for fastening to a receptacle of the process environment. The process connection can comprise a flange or be formed thereby. The flange may be in the form of a disc. The disk shape can have a central aperture, i.e. be ring disk-shaped. The process connection can comprise a fastening bracket or fastening bracket.If the detector is arranged on one side of the process connection on the sensor and the sensor electronics on the other or if the sensor electronics is arranged outside the container when the sensor is fastened as intended in the process environment, then the heat exchanger can protect the sensor electronics particularly effectively from overheating.The sensor electronics preferably comprise an integrated circuit. The maximum operating temperature of the sensor electronics is preferably less than 250 degrees Celsius or 100 degrees Celsius or 70 degrees Celsius or 50 degrees Celsius.The container may be at least substantially closed. The process medium can rest in the container. The container can also be a tube or a channel in which the process medium flows.In one embodiment, the housing houses exclusively or primarily the sensor electronics. In particular in this embodiment, the sensor can have an outer sensor housing and the housing can be arranged within this outer sensor housing.The housing may itself be an outer housing. In addition to the sensor electronics, the housing can at least partially enclose further components of the sensor, for example the detector. The sensor electronics can then be arranged in a region of the housing. This region is referred to in particular as the electronics housing region in the context of this publication.In an advantageous embodiment variant, the heat exchanger is exclusively or primarily configured or arranged on the sensor such that it reduces the transport of thermal energy, in particular conductive and / or effected by thermal radiation, between the container or the process medium on the one hand and the sensor electronics or the housing or the electronics housing region on the other hand. Surprisingly, it has been found that this can be achieved particularly well by a heat exchanger instead of or in addition to a thermal insulation device between, on the one hand, the container or the process medium and, on the other hand, the sensor electronics or the housing or the electronics housing region.The term "heat exchanger" includes any heat sink or radiator and any heat transfer component. The heat exchanger preferably brings about cooling or heating of the sensor or of regions of the sensor, in particular of the process connection and / or of a sensor neck. The exclusive or principal thermal effect of the heat exchanger is preferably to reduce the conductive / or heat radiation-induced transport of thermal energy between, on the one hand, the container or the process medium and, on the other hand, the sensor electronics or the housing or the electronics housing region. In one embodiment variant, the heat exchanger does not reduce the heat flow flowing from the container or the process medium into the sensor, unlike an insulation element, for example. Preferably, the heat exchanger at least partially dissipates this heat flow before it reaches the housing or the electronics housing region or the sensor electronics.The detector may be a sensor. In one embodiment variant, the detector has a mechanical oscillation unit, for example an oscillation fork. The sensor can have a membrane that can be excited to oscillate via a drive unit. The mechanical vibration unit may be disposed on the diaphragm. Preferably, the mechanical oscillation unit can be set into an oscillation by means of the drive unit. The drive unit can comprise a piezoelectric element. The drive unit can have an inductive effect. Depending on a level of coverage of the mechanical oscillation unit with a filling material and depending on the viscosity of this filling material, the mechanical oscillation unit preferably oscillates with a characteristic frequency, which is preferably detected by the sensor and can be converted into a measurement signal. Alternatively, the detector comprises an optical detector, for example a turbidity measuring device, which preferably operates optically. The detector can also comprise a radar device, for example, the sensor can thus be a radar sensor. The sensor can also be a pressure sensor.If the sensor is suitable for high-temperature applications, for example those in which very high temperatures prevail within the process medium and / or the container itself has a very high temperature, then the advantages of the invention are particularly evident. This applies in particular when the sensor is configured to be arranged close to the container, since the heat transferred from the process medium and / or container to the sensor electronics can then represent a challenge for the sensor.A particularly reliable and / or space-saving high-temperature suitability of the sensor can be achieved by the heat exchanger. In addition to the heat exchanger, the sensor can have a temperature intermediate piece which shields the sensor electronics from radiant heat of the process medium and / or container, creates a distance between the process medium or the container and the sensor electronics, and / or can thermally decouple the sensor electronics from the process medium or the process connection. The temperature spacer may be a thermal insulator. If the sensor manages without such a temperature intermediate piece, it can be of particularly compact construction. If the sensor manages without such a temperature intermediate piece, then the sensor electronics can be built closer to the detector or the process medium or the container, which can save resources. Preferably, the heat exchanger protects the sensor electronics more effectively from heat than such a temperature intermediate piece.A very high temperature means in particular a temperature that is higher than 200 degrees Celsius or 250 degrees Celsius. Preferably, the very high temperature is less than 500 degrees Celsius or 450 degrees Celsius.If the sensor is configured to be attached to a receptacle of the process environment that is arranged above the container or at the upper region of the container, the advantages of the invention are again particularly well realized. This is because the warm air then rises and the sensor must be particularly temperature-resistant in order to avoid damage to the sensor electronics.The heat exchanger is additively manufactured. Additive manufacturing is preferably 3D printing. Due to the small batch size in the additive manufacturing method, the heat exchanger can be adapted to the specific application and can nevertheless be manufactured economically. Due to the additive manufacturing, the geometry of the heat exchanger can be optimized such that heat can be dissipated in an optimum manner. The additively manufactured heat exchanger can have very complex geometries optimized with respect to heat conduction due to the additive manufacturing method.The heat exchanger can comprise or be formed from thermally conductive plastics.In an advantageous embodiment variant, the heat exchanger comprises metal or is formed from metal.In a particularly advantageous embodiment variant, the additive manufacturing is metal 3D printing. The 3D pressure, and in particular the metal 3D pressure, may be powder bed fusion. The metal 3D printing can be effected by means of a nonmetallic binder and can be, for example, metal binder blasting technology. The metal 3D pressure can be indirect, i.e. comprise the debindering and sintering in furnace processes.In an advantageous embodiment variant, the metal 3D pressure is direct metal pressure. The direct metal pressure can be embodied as direct metal laser sintering (DMLS). Metal powder is preferably melted in layers. The direct metal pressure is preferably binder-free. The direct metal pressure is preferably free of adhesive. The metal can be, for example, steel, stainless steel, brass or aluminum. Preferably, at least almost the same strength of the heat exchanger is achieved by the metal 3D pressure as in a conventionally produced metal component.In one variant, the heat exchanger is arranged at the process connection. If the process port comprises or is formed by a flange, then the heat exchanger may be connected to the flange.If the heat exchanger is alternatively or additionally to this variant at least also formed by the process connection or is installed as a process connection in the sensor, then the additional manufacturing outlay associated with the heat exchanger can be limited. This is because the process connection that is necessary in any case then merely has to be extended by the functionality of the heat exchange.The heat exchanger can alternatively or additionally be arranged between the process connection and the housing or the electronics housing region. The sensor advantageously has a sensor neck. The sensor neck preferably comprises all sensor components or regions of these sensor components arranged between, on the one hand, the process connection and, on the other hand, the housing or the electronics housing region or the sensor electronics. In one embodiment variant, the sensor neck or a region of the sensor neck is formed by the heat exchanger. The sensor neck or a region of the sensor neck can comprise a housing neck or be formed thereby. The housing neck may be contiguous with the housing or form a portion of the housing. The housing neck can adjoin the electronics housing region. The housing neck may be different from the housing.The sensor neck or the housing neck can have a neck-like constriction. In an alternative embodiment, the sensor neck or the housing neck does not have a neck-like constriction.The heat exchanger can be integrated into the housing or the housing neck. Alternatively or additionally to the variant in which the heat exchanger is arranged on the process connection or is at least also formed by the process connection, the heat exchanger is formed by the sensor neck of the sensor or a region of the sensor neck. The heat exchanger can therefore also assume a housing function such as, for example, protection and sealing.The heat exchanger is designed to be load-bearing, i.e. to absorb mechanical sensor holding forces.If the heat exchanger is multifunctional, i.e. has at least one further function in addition to its function of heat exchange or heat transfer, for example a process connection function and / or a housing function, then the additional outlay associated with the heat exchanger can be reduced. A "process connection function" refers in particular to a sensor fastening function. This is because the heat exchanger can then be provided instead of the component that it takes over the function of. It has been found that the complexity of the shaping or load-bearing capacity associated with the multifunctionality of the heat exchanger can be achieved particularly well in the embodiment in which the heat exchanger is additively manufactured.In one variant, the heat exchanger has at least one fluid channel, for example a spiral-shaped fluid channel, through which heat carrier medium can be conducted by means of at least one heat carrier medium connection. Therefore, the heat exchanger can be designed particularly effectively, with a small space requirement. In addition, the heat exchanger can then, in a particularly advantageous manner, have not only a cooling function but also a heating function. By suitable temperature control of the heat transfer medium, either a cooling or a heating effect on the sensor or the process connection can be achieved. A cooling effect can be advantageous in order to protect the sensor electronics or the flange itself from excessively high temperatures. A heating effect can offer advantages in very cold processes or in very cold ambient conditions, in order to avoid, for example, icing of the sensor electronics or also condensate formation on the sensor electronics.The fluid channel can run in at least two planes.Preferably, a pump assembly for pumping the heat transfer medium through the at least one fluid channel can be connected to the sensor, preferably by means of the at least one heat transfer medium connection, preferably forming a closed heat transfer medium circuit. The heat transfer medium can be a heating or cooling medium. The heat transfer medium can be a gas. The heat transfer medium is preferably a heat transfer liquid. In an advantageous embodiment variant, the heat exchanger or the process connection is manufactured in such a way that a liquid supply can be connected to its at least one fluid channel, in a similar manner to a water cooling of an internal combustion engine, for example. The heat transfer medium connection can comprise, for example, hose couplings. In particular if the pump assembly is external to the sensor, i.e. not integrated therein, the pump assembly can comprise a temperature control assembly. Heat of the heat transfer medium can then be emitted to the sensor at a distance from the temperature control unit.It has been found that in the embodiment in which the heat exchanger is additively manufactured, the at least one fluid channel can be laid particularly finely and / or complex and / or in any angle of the heat exchanger or process connection. This can allow precise temperature control of individual partial regions of the process connection or of the sensor neck by appropriate design of the line guide. In addition, liquid heating / cooling can be realized even in the case of very small heat exchangers or process connections or sensor necks, since the at least one fluid channel can be correspondingly thin. By means of a plurality of individual channels, fluid channel sections or by means of a very long fluid channel, a very large surface area can be used and realized for the heat transfer between the material of the heat exchanger, in particular metal, and the heat transfer medium. Preferably, the walls forming the fluid channel have a closed cross section. The fluid channel cross section can be circular. The fluid channel cross section can be polygonal, e.g. square.The fluid channel can have fluid channel branches. The fluid channel can have fluid channel junctions. The fluid channel may cross itself at fluid channel intersections. The fluid channel can form a line network. The line network may comprise nodes. The nodes may be formed by fluid channel branches and / or fluid channel junctions and / or fluid channel intersections. The fluid channel can extend adjacent to itself-at least in regions or predominantly-in the heat exchanger with constant spacing, for example by a spiral or meandering arrangement of the fluid channel. The line network and / or the region of the heat exchanger in which the fluid channel runs adjacent to itself can increase the cooling or heating effect of the heat exchanger. The line network and / or the region of the heat exchanger in which the fluid channel runs adjacent to itself can have a high spatial complexity in order to optimally distribute the heat or cold in each region of the heat exchanger. If the heat exchanger has a line network and / or a region in which the fluid channel runs adjacent to itself, then the line network and / or this region is preferably formed by the process connection or the sensor neck or is arranged on the process connection.The fluid channel preferably has exactly one fluid channel inlet and / or exactly one fluid channel outlet. The fluid channel inlet and the fluid channel outlet can be arranged opposite each other. The fluid channel inlet and the fluid channel outlet can be arranged next to one another. Preferably, the at least one heat transfer medium connection is arranged at the fluid channel inlet and / or the fluid channel outlet. The fluid channel can have a constant cross section. Alternatively, the cross section of the fluid channel can change over the fluid channel length. The cross-sectional area of the fluid channel can be between 100 mm 2 and 0.5 mm 2, between 50 mm 2 and 0.5 mm 2, between 10 mm 2 and 0.5 mm 2 or between 5 mm 2 and 0.5 mm 2. If the length of the at least one fluid channel or the total length of the channels is greater than 1 m or 5 m, then effective heating or cooling can be achieved. If the length of the at least one fluid channel or the total length of the channels is less than 50 m or 10 m, then the flow resistance can remain within a reasonable scope. The volume of the at least one fluid channel in the heat exchanger can be greater than the material volume of the heat exchanger. The heat exchanger can therefore predominantly consist of the at least one fluid channel. In an advantageous embodiment variant, the at least one fluid channel extends uniformly in the entire heat exchanger or the entire process connection. The line network and / or the region in which the fluid channel runs adjacent to itself can fill any region of the heat exchanger or process connection or housing neck. By means of at least one fluid channel of this type, a large heating or cooling effect can be achieved even with small heat exchangers.If the heat exchanger, in particular in the embodiment in which the heat exchanger is formed by the sensor neck or a region of the sensor neck, has air cooling surfaces for enlarging its surface area, then it can be particularly economical to operate despite a large temperature application range. The cooling effect can be increased by air movements acting on the heat exchanger. As a result, the sensor electronics can be built closer to the detector or the process medium or the container, which can save resources.The air movement can be effected by wind, in particular when the container is arranged under a free sky. The air movement can be forced, for example by a fan and / or by utilizing different air temperatures, in particular caused by the heating of air, for example by the container and / or the process medium.In the embodiment with an additively manufactured heat exchanger, geometries, in particular of the air cooling surfaces and / or of the at least one fluid channel, can be realized which are distinguished by a particularly good cooling or heating effect with a low space or material requirement of the heat exchanger and which would not be producible by means of conventional machining production methods or casting methods or would only be producible with an uneconomically increased outlay.In particular, if the heat exchanger preferably having air cooling surfaces is arranged on the process connection, then the process connection preferably has a side facing the process ambient air. The heat exchanger can then be arranged on this side at the process connection. In this way, for example, the housing or the electronics housing region can be effectively protected against heat transfer of the container, preferably without a temperature intermediate piece being necessary.By increasing the surface area of the heat exchanger, the heat transfer between the process connection or the sensor neck and the process environment can be improved for improved dissipation of disruptive heat.The air cooling surfaces may be cooling fins.In a particularly advantageous embodiment variant, the ratio of the surface area of the heat exchanger to its structural volume is greater than 0.5 cm 2 / cm 3, 5 cm 2 / cm 3, 10 cm 2 / cm 3 or 100 cm 2 / cm 3. The term "construction volume" refers in particular to the space requirement or installation space requirement of the heat exchanger, which is no longer available for other components of the sensor or of the process environment. The term "surface of the heat exchanger" also encompasses, within the scope of this publication, the inner surface of any fluid channel.A measuring arrangement according to the invention comprises a sensor according to this disclosure and a container in which the process medium is arranged. The sensor is fastened to the container by means of the process connection. For fastening the sensor, the process environment, i.e. for example the container, preferably has a receptacle which can be designed, for example, as a clamping or pipe screw connection piece. The receptacle may be available or insertable on the container and may include a sensor attachment means. The receptacle may include a container aperture. The measuring arrangement preferably comprises the pump assembly. The measuring arrangement preferably comprises a closed heat carrier medium circuit. Preferably, the pump assembly or the pump and temperature control assembly and the at least one fluid channel is part of a closed heat carrier medium circuit.A process plant according to the invention comprises a measurement arrangement according to this disclosure. If the container of this measuring arrangement is arranged under free sky, the cooling effect can be increased by wind acting on the heat exchanger.A method according to the invention for operating a sensor according to this disclosure is characterized in that the sensor is cooled or heated.In an advantageous embodiment, the process connection is cooled or heated.In an advantageous embodiment, the sensor neck is cooled or heated.In an advantageous embodiment, only the process connection is cooled or heated by means of the heat exchanger.In another embodiment, only the sensor neck is cooled or heated by means of the heat exchanger.In a further embodiment, only the process connection and the sensor neck are cooled or heated by means of the heat exchanger.The heat exchanger is preferably supplied with preferably liquid heating or cooling medium, for example by means of a pumping and tempering unit.The present invention is explained in detail below on the basis of exemplary embodiments with reference to the appended figures. The following are shown: FIG. 1 is a partially cut-away side view of a first exemplary embodiment of a sensor, FIG. 2 shows a cross-sectional illustration of the heat exchanger of the sensor from FIG. 1, FIG. 3 shows a schematic illustration of the heat transport in a sensor known from the prior art without a heat exchanger, FIG. 4 shows a schematic illustration of the heat transport in the sensor shown in FIG. 1, FIG. 5 is a perspective view of an example of a sensor not belonging to the invention.In the figures, unless otherwise indicated, the same reference numerals designate the same components having the same function.The sensor 1 of the first exemplary embodiment shown in FIG. 1 and suitable for high-temperature applications is a radar sensor for process measurement technology for measuring the fill level of a process medium M located in a container 2.The sensor 1 has a radar device as detector 3, a process connection 4 designed as an annular flange 18, sensor electronics 5, and a housing 6. The sensor electronics 5 are arranged in the housing 6. The sensor 1 comprises a heat exchanger 7.The sensor 1 is fastened to a receptacle 15 of the process environment, more precisely the container 2, which is arranged at the upper region of the container 2 and comprises container aperture.The sensor 1 has a sensor neck 8. The sensor neck 8 comprises all sensor components arranged between the process connection 4 and the housing 6, more precisely the electronics housing region. The sensor neck comprises a housing neck 9.The heat exchanger 7 is additively manufactured by metal 3D pressure through powder bed fusion.The heat exchanger 7 is multifunctional, promoted by additive manufacturing, since it has a process connection function in addition to its function of heat exchange or heat transfer. The heat exchanger 7 replaces the conventional process connection.The heat exchanger 7 has a spiral fluid channel 10, through which heat transfer medium can be conducted by means of two heat transfer medium connections 11. The fluid channel 10 has exactly one fluid channel inlet and exactly one fluid channel outlet. The fluid channel inlet and the fluid channel outlet are arranged opposite each other. One heat transfer medium connection 11 is arranged at the fluid channel inlet and the other heat transfer medium connection 11 is arranged at the fluid channel outlet. The fluid channel runs in three planes E 1, E 2, E 3.FIG. 1 also shows an exemplary embodiment of a measuring arrangement 17. this comprises the sensor 1 and the container 2 in which the process medium M is arranged. The sensor 1 is fastened to the container 2 by means of the process connection 4 designed as a heat exchanger 7. For fastening the sensor, the container has the receptacle 15. The pumping and tempering unit 12 and the closed heat transfer medium circuit are not shown in FIG. 1 for the sake of simplicity of illustration.As is shown in FIG. 1 as well, which illustrates the heat exchanger 7 in cross section, the fluid channel 10 is particularly fine and complex due to the additive manufacturing and is laid in any angle of the heat exchanger 7 or of the process connection 4. The fluid channel 10 runs in the heat exchanger 7 predominantly with constant distance adjacent to itself. The region 16 of the heat exchanger 7, in which the fluid channel 10 runs adjacent to itself, has a high spatial complexity in order to optimally distribute the heat or cold in each region of the heat exchanger 7. The sensor 1 does not require any temperature intermediate piece. The two arrows P in FIGS. 1 and 2 indicate the flow of the heat transfer medium.The process connection 4 is cooled by the heat exchanger 7 being charged with liquid cooling medium.FIG. 3 shows the heat transport symbolized by arrows in a sensor known from the prior art without a heat exchanger. The heat flows from the container 2 through the process connection 4 of the sensor to the sensor electronics 5.FIG. 4, in which the heat transport is likewise symbolized by arrows, shows that the heat exchanger 7 at least partially dissipates the heat transport in the sensor shown in FIG. 1 before it reaches the housing 6.In addition, FIG. 4 schematically shows the pump assembly 12 for pumping the heat transfer medium through the at least one fluid channel 10. Heat of the heat transfer medium can be emitted to the sensor 1 at a distance from the temperature control unit, as is symbolized by the two arrows drawn on the right in FIG. 4. The heat is dissipated from the pumping and tempering unit 12 to the process environment. The pumping and tempering unit 12 and the fluid channel 10 are part of a closed heat carrier medium circuit.In the second exemplary embodiment of the sensor 1 shown in FIG. 5, the heat exchanger 7 is not formed by the process connection 4, which is also embodied here as an annular disk-shaped flange 18. Instead, a region of the sensor neck 8, more precisely a region of the housing neck 9, is formed by the heat exchanger 7. The heat exchanger 7 is multifunctional also in this embodiment, since it has a housing function in addition to its function of heat exchange. Only the differences from the first exemplary embodiment are shown below:The example not belonging to the invention shown in FIG. 5 is a limit level sensor and the detector 3 comprises a mechanical vibration unit, namely a vibration fork. Instead of a fluid channel, the heat exchanger 7 has air cooling surfaces 13 designed as cooling ribs for enlarging its surface 14.List of reference characters1 Sensor 2 Container 3 Detector 4 Process connection 5 Sensor electronics 6 Housing 7 Heat exchanger 8 Sensor neck 9 Housing neck 10 Fluid channel 11 Heat transfer medium connection 12 Pump and temperature control unit 13 Air cooling surfaces 14 Surface 15 Receptacle 16 Region of the heat exchanger 17 Measuring arrangement 18 Flange E 1, E 2, E 3 Planes P Arrows M Process medium

Claims

Sensor (1) for process measurement technology for measuring a physical and / or chemical process variable of a process medium (M) located in a container (2), wherein the sensor (1) comprises a fill level sensor or a limit level sensor, having a detector (3), a process connection (4), sensor electronics (5) and a housing (6), wherein the sensor electronics (5) are arranged in the housing (6), wherein the sensor (1) comprises a heat exchanger (7), wherein the heat exchanger (7) supports, i.e. for absorbing mechanical sensor holding forces, wherein a) the heat exchanger (7) is arranged on the process connection (4) or at least is also formed by the process connection (4) and / or b) the sensor (1) has a sensor neck (8) and the heat exchanger (7) is formed by the sensor neck (8) or a region of the sensor neck (8), wherein c) the heat exchanger (7) has at least one fluid channel (10), which is for example helical and / or meandering, and the fluid channel (10) has a heat carrier medium connection (11), wherein the heat exchanger (7) is additively manufactured, so that it can have very complex geometries optimized with regard to heat conduction.Sensor according to Claim 1, characterized in that the additive manufacturing is 3D printing.Sensor according to Claim 2, characterized in that the additive manufacturing is metal 3D printing.Sensor (1) according to one of Claims 1 to 3, wherein the sensor (1) has a sensor neck (8) and the heat exchanger (7) is formed by the sensor neck (8) or a region of the sensor neck (8), characterized in that the sensor neck (8) or a region of the sensor neck (8) comprises a housing neck (9) or is formed as a result.Sensor (1) according to any one of claims 1 to 4, characterized in that the heat exchanger (7) is multifunctional.Sensor according to one of Claims 1 to 5, characterized in that the fluid channel (10) runs in at least two planes (E1, E2, E3).Sensor according to one of Claims 1 to 6, characterized in that a pump assembly (12) for pumping the heat transfer medium through the at least one fluid duct (10) can be connected to the sensor (1) by means of the heat transfer medium connection (11).Sensor (1) according to one of Claims 1 to 7, characterized in that the heat exchanger (7) has air cooling surfaces (13) for enlarging its surface (14).Sensor (1) according to one of Claims 1 to 8, characterized in that the ratio of the surface (14) of the heat exchanger (1) to its structural volume is greater than 0.5 cm 2 / cm 3, 5 cm 2 / cm 3, 10 cm 2 / cm 3 or 100 cm 2 / cm 3.Measuring arrangement (17) with a sensor (1) according to one of Claims 1 to 9 and with a container (2) in which process medium (M) is arranged, characterized in that the sensor (1) is fastened to the container (2) by means of the process connection (4).Process plant with a measuring arrangement (17) according to Claim 10, characterized in that the container (2) is arranged under free sky.Method for operating a sensor (1) according to one of Claims 1 to 9, characterized in that the sensor (1), preferably the process connection (4), is cooled or heated.Method according to claim 12, wherein the sensor (1) has a sensor neck (8) which comprises all sensor components or regions of sensor components arranged between the process connection (4) and the housing (6), characterized in that the sensor neck (8) is cooled or heated.Method according to Claim 12 or 13, characterized in that the heat exchanger (7) is acted upon by heating or cooling medium.

Images