Sensor electrode for halogen determination and method for manufacturing a sensor electrode

Abstract

The invention relates to a sensor electrode (1) for halogen determination. Electrode pins (2, 3, 4) project beyond or are flush with an end face (70) of an electrode shaft (7). An electrode pin (2, 3, 4) is electrically and mechanically connected to an insert (5) arranged in the electrode shaft (7). A connection component (6) is arranged on the other end face (71) of the electrode shaft (7), with the insert (5) being electrically and mechanically connected to the connection component (6). The electrode shaft (7) is produced by an injection molding process, and the electrode pins (2, 3, 4) are embedded in the electrode shaft (7). The invention further relates to a method for manufacturing a sensor electrode (1).

Description

[0001] The invention relates to a sensor electrode for halogen determination. Furthermore, the invention relates to a method for manufacturing a sensor electrode for halogen determination.

[0002] Biamperometry is a known technique for determining trace amounts of halogens (other than fluorine, i.e., chlorine, bromine, or iodine). This is a variant of amperometry that uses two identical working electrodes. An electrolytic current flows only when a reaction occurs at both electrodes. The halogen content is then determined from the conductivity of the electrolyte. A typical application is AOX analysis according to ISO standard 9562. In this method, organochlorine compounds are adsorbed onto activated carbon. The samples prepared in this way are combusted in an oxygen stream in an oven, and the resulting HCl (HX) is quantified in a coulometric measuring cell after drying with sulfuric acid.

[0003] From DE 42 31 960 A1, a sensor electrode can be derived in which two electrode pins are combined as working electrodes in a single component. The electrical connection components of the electrode pins are arranged in an electrode shaft made of ceramic. The electrode pins project beyond the end face of the electrode shaft or are flush with the end face in order to come into contact with the electrolyte for the determination of the chloride content.

[0004] For such a sensor electrode, the accuracy and precision of the measurement results depend on the effective surface area of ​​the electrode pins and the distance between them being consistent across all sensor electrodes. Furthermore, it is essential to ensure that the electrode pins are properly sealed within the ceramic shaft. Both of these requirements make automated manufacturing of the sensor electrodes virtually impossible, necessitating costly manual labor.

[0005] DE 10 2008 054 659 A1 describes how conductive conductivity sensors are produced using an injection molding process. DE 10 2018 121 787 A1 discloses an electrode assembly for an amperometric sensor whose electrode body is produced by an injection molding process. DE 10 2017 220 847 A1 describes a conductivity sensor produced by a plastic injection molding process, whereby the electrodes are embedded. DE 10 2021 112 181 A1 describes a sensor whose conductive traces – e.g., made of silver – can be overmolded. DE 10 2016 110 856 A1 states that an electrode assembly is manufactured in the form of an injection-molded formwork support.

[0006] The object of the invention is to propose a sensor electrode for halogen determination that can be manufactured as simply as possible without compromising the quality of the measurements. Furthermore, the object is to propose the simplest and most reliable manufacturing process possible for such a sensor electrode.

[0007] The problem is solved by a sensor electrode for halogen determination, wherein the sensor electrode has at least two electrode pins, an elongated, plate-like insert, a connection component and an electrode shaft, wherein the electrode shaft has two opposing end faces, wherein the electrode pins are arranged such that the electrode pins project beyond one end face of the electrode shaft or are flush with the end face, wherein at least one electrode pin is electrically and mechanically connected to the insert, wherein the insert is arranged in the electrode shaft, wherein the connection component is arranged on the other end face of the electrode shaft, wherein the insert is electrically and mechanically connected to the connection component, and wherein the electrode shaft is at least partially produced by an injection molding process.and wherein the electrode pins are at least partially embedded in the electrode shaft.

[0008] The sensor electrode according to the invention comprises at least two electrode pins, an elongated, plate-like insert, a connection component, and an electrode shaft. The insert is elongated and plate-like. In one embodiment, the insert is at least partially made of printed circuit board material. The insert serves both as a basic mechanical structure for the electrode and as the electrical contact point for the electrode pins.

[0009] The electrode shaft is, for example, essentially cylindrical or circular-cylindrical in shape. It has an end face from which the electrode pins protrude or with which they are flush. For electrical measurements, the electrode pins are connected to the insert located within the electrode shaft. The insert is guided through the electrode shaft, held in place by the shaft, and thus protected from the environment. The electrode shaft is produced at least partially or entirely by injection molding. Injection molding allows components to be embedded directly into the electrode shaft, thereby sealing them. Furthermore, the insert is securely protected against tensile stress within the electrode shaft. Injection molding also enables the creation of electrode shafts with specific geometries.Furthermore, the electrode shaft has another end face, which can also be called the neck or neck end face or connection end face, and which is turned away from the process and serves, for example, to fix the electrode shaft in a wall, etc.

[0010] Overall, sensor electrodes with reproducible properties can be manufactured cost-effectively. The injection molding material is preferably electrically insulating. Preferably, such a material is also used or processed in such a way that the electrode shaft has the smoothest possible outer surface, which is easy to clean and minimizes carryover. By partially embedding the electrode pins in the electrode shaft, good sealing, precise pin positioning, and very good mechanical stability are achieved. The connection component allows the electrode to be connected to wires and therefore also to other devices.

[0011] An electrode pin is configured as a cathode pin and serves as the generator cathode. The sensor electrode is preferably used in a coulometric measuring cell consisting of the two sensor electrodes (preferably made of silver) and a generator electrode pair. Particularly in the case of coulometric chloride titration, the generator system consists of a platinum cathode and a silver anode. The generator cathode (preferably made of platinum) is integrated with the cathode pin in the sensor electrode. This is advantageous because the volume of the measuring cell is small, allowing the electrodes to be arranged in a space-saving manner.

[0012] In one embodiment of the sensor electrode, the electrode shaft consists at least partially of a plastic. In this embodiment, an injection molding process is carried out using a plastic. The plastic is preferably polypropylene. Preferably, the plastic is chemically resistant, particularly to concentrated acetic and sulfuric acid. For example, the plastic is a polyvinylidene fluoride (PVDF), which is characterized by hardness, density, and resistance to chemicals. The plastic is generally characterized by its moldability. It is, for example, a thermoplastic, thermoset, or elastomer. The plastic's durability is important for its selection, relating both to the internal components (i.e., primarily thermal resistance) and to the external components during the sensor electrode's application, specifically to potential environmental factors.This relates to existing chemicals (primarily chemical resistance). The plastic should also be characterized by neither swelling nor shrinking during the use of the sensor electrode, in order to ensure a tight seal.

[0013] One embodiment of the sensor electrode includes two electrode pins made at least partially of silver. The sensor electrode with the silver electrode pins is used in particular for the determination of halogens, preferably chloride. The injection molding process allows the electrode pins to be tightly encased. This contrasts with the difficulties in the prior art, which, for example, does not permit the encapsulation of silver pins in glass.

[0014] In another embodiment, two electrode pins consist at least partially of platinum. The associated sensor electrode can be used, for example, for the biamperometric determination of SO2.

[0015] One embodiment of the sensor electrode includes a cathode pin. This pin is preferably made at least partially of platinum.

[0016] In one embodiment, the sensor electrode has at least two inserts.

[0017] One embodiment is characterized in that the sensor electrode has at least two inserts, that the two inserts have electrical conduction structures, that the two electrode pins, which are at least partially made of silver, are connected to the electrical conduction structures of one insert, and that the electrode pin, which is at least partially made of platinum, is connected—directly or indirectly—to the electrical conduction structures of the other insert. In this embodiment, the three electrode pins are distributed between the two inserts by connecting two silver electrode pins to the conduction structures of one insert and one platinum electrode pin to the conduction structures of the other insert. In one of the following embodiments, it is specifically provided that the platinum electrode pin is indirectly connected to the conduction structures of the other insert via an adapter sleeve.

[0018] In a further embodiment, an additional electrode pin serves as a generator anode. This embodiment is preferably combined with the sensor electrode having four electrode pins. This results in a compact 4-electrode system, which is implemented as a single assembly.

[0019] One embodiment of the sensor electrode features a connection component that allows for a reversible electrical connection between the sensor electrode and a plug. In this embodiment, the sensor electrode can be reversibly connected to a plug. This simplifies, for example, the replacement or cleaning of the sensor electrode. A control or evaluation circuit, for instance, is connected to the plug.

[0020] One embodiment of the sensor electrode includes an electrode shaft with at least one receiving groove for a sealing component. This sealing component is, for example, an O-ring that is inserted into the receiving groove. The sealing component seals, for example, the transition between the electrode shaft and a part of a measuring cell containing the reaction fluid or electrolyte to be measured.

[0021] One embodiment provides that the sensor electrode has at least two inserts, that at least one insert has electrical conduction structures, and that the inserts are designed and arranged relative to each other such that the planes in which the inserts primarily extend are substantially perpendicular to one another. In this embodiment, there are two inserts, each extending primarily longitudinally and each, for example, partially designed as a printed circuit board or made of printed circuit board material. The two inserts are intended to be perpendicular to each other, so that they form a stable basic structure for the elongated electrode shaft. At least one insert has an electrical conduction structure to which at least one electrode pin can therefore be connected. In one embodiment, both inserts each have a conduction structure.

[0022] The following details relate to the inserts and their relative arrangement, or rather, the overall geometric structure they form. It should be noted that the inserts both form the basic structure of the electrode shaft and serve as the electrical connection between the electrode pins and the terminal component. Ultimately, the inserts determine the outer extent of the electrode shaft. The geometry of the inserts should preferably be selected such that the insert(s) can withstand the injection molding process during the manufacturing of the electrode shaft.

[0023] One design involves the inserts being shaped and arranged relative to each other in such a way that together they essentially form a T-shape. The T-shape refers to the capital letter T. In one embodiment, the crossbar is slightly pierced by the vertical bar.

[0024] One embodiment provides that the inserts are designed and arranged relative to each other in such a way that together they essentially form a plus sign. In this embodiment, the two inserts form an X, cross, or plus sign. In one embodiment, the four components of the plus sign have essentially the same length. The shape of each insert is revealed in a section perpendicular to its longitudinal axis.

[0025] In an alternative embodiment, there is only one insert, which is either T-shaped or plus-shaped. In one embodiment, there is a central support structure with a further transverse substructure attached to one end (i.e., a T-shape). Alternatively, two support structures intersect—preferably near their respective centers—preferably forming right angles (i.e., a plus-shape). As an alternative to the latter, the two support structures can intersect at an obtuse or acute angle (i.e., a cross or, for example, a St. Andrew's cross shape).

[0026] One embodiment includes a sensor electrode with at least two inserts, at least one of which has electrical conductor structures, and the inserts being designed and arranged relative to each other such that one insert at least partially extends through the other. In this embodiment, the two inserts are connected by one insert extending through the other. This results in relatively simple mechanical stability. In particular, this embodiment is characterized by one insert being designed such that the other insert can pass through it.

[0027] A further embodiment involves connecting the at least two inserts to each other via solder points. These solder points also serve to stiffen the two inserts. In one embodiment, solder points are present along the entire length where the two inserts are in direct contact with each other.

[0028] In an alternative or supplementary embodiment, the at least two inserts are connected to each other via adhesive points. In this embodiment, an adhesive is used.

[0029] One embodiment provides that at least one electrode pin - and preferably two electrode pins - is connected to the electrical conductor structures of the insert by means of a soldered connection.

[0030] One embodiment includes at least one electrode pin being resiliently mounted in an adapter sleeve and electrically connected to the adapter sleeve, and the adapter sleeve being electrically connected to the electrical conductors of the insert. This embodiment takes into account that some types of electrode pins cannot be soldered to other components—in this case, the insert—or not without considerable effort. This applies, for example, to the material platinum. Therefore, the embodiment includes an adapter sleeve that provides at least mechanical stabilization and basic electrical contact. The adapter sleeve is designed to allow, for example, a soldered connection to the conductors of the at least one insert. For this purpose, the adapter sleeve has, in particular, a spring-loaded contact that electrically connects the electrode pin.

[0031] One embodiment provides that the electrode pin, located in the adapter sleeve, is inserted into the adapter sleeve and fixed and sealed as a result of the electrode shaft being produced by the injection molding process. In this embodiment, the injection molding process used to produce the electrode shaft also seals the area of ​​the electrode pin and the adapter sleeve.

[0032] One embodiment involves the connection component being designed as a multi-pole socket facing the insert. In one embodiment, this is particularly a three-pole socket to which three electrode pins are connected – indirectly via the at least one insert.

[0033] One embodiment provides that the electrode shaft and the connection component are designed and arranged such that the cross-section of the connection components along the electrode shaft is essentially always symmetrical. In this embodiment, the insert(s) are designed and implemented such that the cross-section through the electrode shaft is always symmetrical. This is intended to prevent material accumulation during the manufacturing of the electrode shaft. Such accumulations often lead to distortion and should therefore be avoided. In particular, it is preferably ensured that the individual components of the sensor electrode maintain constant distances from the inner surface of a mold, which may be used in the injection molding process. This makes it possible to achieve an essentially straight and completely closed encapsulation of the inner parts of the electrode shaft.Furthermore, this avoids asymmetrical forces during the injection molding process.

[0034] Furthermore, the problem is solved by a method for manufacturing a sensor electrode for halogen determination, wherein the method comprises at least the following steps: that several electrode pins are arranged relative to each other, that at least one electrode pin is electrically and mechanically connected to an insert, that an electrode shaft is produced at least partially around the electrode pins and around the insert by an injection molding process such that the electrode pins and the insert are at least partially embedded in the electrode shaft, and that at least one electrode pin partially projects beyond an end face of the electrode shaft, and that after the production of the electrode shaft, the extent by which at least one electrode pin projects beyond the end face is changed.

[0035] The descriptions and explanations regarding the sensor electrode also apply to the process and vice versa, so repetition is omitted. The sensor electrode is preferably an electrode manufactured using the process.

[0036] According to the invention, the two electrode pins are arranged to match each other – e.g., in a mold – in order to subsequently produce the electrode shaft using injection molding. At least one electrode pin is connected to the insert, and the electrode shaft is formed around the pins and the insert. The electrode pins are inserted into the electrode shaft at one end and protrude beyond it at another end or are flush with the surface to come into contact with the medium whose chloride content is to be determined. Furthermore, after the electrode shaft has been produced, at least one electrode pin is machined in terms of dimensions, and thus with respect to the reaction surface, to achieve, for example, a desired measurement accuracy.

[0037] In one embodiment, two inserts are nested together. Two electrode pins are then soldered to the conductive structures of at least one insert. One electrode pin is inserted into an adapter sleeve, which is also electrically connected to the conductive structures of the inserts, e.g., by soldering. The electrical connections are electrically insulated from each other. The assembly is fixed in a mold by utilizing the protruding elements, e.g., the electrode pins. The electrode shaft is then produced via injection molding.

[0038] The invention is explained in more detail with reference to the following figures. Fig. Figure 1 shows a cross-section through a schematic measuring setup for determining the chloride content, Fig. Figure 2 shows the components of a sensor electrode in an exploded view, Fig. Figure 3 shows part of the sensor electrode of the Fig. 2 in the compound state, Fig. 4 shows the components of the Fig. 2 in the assembled state, Fig. Figure 5 shows a variant of the components of a sensor electrode in the assembled state and Fig. Figure 6 shows a spatial representation of a section through the components of the Fig. 5.

[0039] The Fig. Figure 1 shows a sensor electrode 1 located in a measuring cell 101. The measuring cell 101 is closed on one side with a measuring cell cover 103, with the sensor electrode 1 protruding through a continuous recess in the measuring cell cover 103. A sealing component 8, arranged in a receiving groove 72 of the electrode shaft 7, which here is e.g. an O-ring, seals the transition between the electrode shaft 7 and the recess of the measuring cell cover 103.

[0040] The reaction liquid 102 is located in the measuring cell 101, into which the two identical electrode pins 2, which here consist in particular of silver, protrude and take place.

[0041] The electrode shaft 7 is essentially cylindrical and has a connection component 6 at its upper end with a larger outer diameter than the inner diameter of the recess in the measuring cell cover 103. This secures the electrode shaft 7 in the measuring cell cover 103. The connection component 6 is further designed so that the sensor electrode 1 can be reversibly electrically connected via a plug 100.

[0042] Opposite the connection component 6, the two electrode pins 2, which are preferably made of silver, are arranged in and embedded in the end face 70 of the electrode shaft 7. Therefore, they are well insulated. For the measurement, a further electrode pin is provided as a cathode pin 3, which also projects beyond the end face 70, is embedded in the end face 70, and is electrically contacted by at least one insert 5. The cathode pin 3 serves as the generator cathode. The fourth electrode pin 4 fulfills the function of the generator anode during the measurement. The at least one insert 5 provides the electrical connections between the electrode pins 2, 3, 4 and the connection component 6 and forms the basic geometric structure of the preferably circular cylindrical electrode shaft 7.

[0043] The Fig. Figure 2 clearly shows that the majority of the spatial extent of the sensor electrode 1 results from the shape of the two inserts 5 shown here. The two inserts 5 are made of printed circuit board material and extend mainly in the longitudinal direction, i.e., along the longitudinal axis of the sensor electrode 1. The inserts 5 have conductive structures 50 that serve for the electrical contacting of the electrode pins 2, 3 and the connection component 6.

[0044] One insert 5 has a recess 51 into which a part of the other insert 5 is inserted. This results in the basic mechanical structure of the electrode shaft 7.

[0045] At the upper (cf. Fig. 1) or, in this case, at the right end, is the connection component 6, which, in the application of the sensor electrode 1, can be connected to a plug 100 and thus to a device required for measurement. In this embodiment, the connection component 6 has three poles 60, which are connected to the three electrode pins 2, 3.

[0046] For the measurements, three electrode pins 2, 3 are provided, two of which are made of silver and one of which is made of platinum. The silver electrode pins 2 are connected to the conductor structures 50 by soldering. The platinum electrode pin 3 is inserted into the adapter sleeve 30 to be spring-mounted and electrically contacted. The sealing of electrode pin 3 in the adapter sleeve 30 is achieved—as with the other electrode pins 2—by the injection molding process, which is also used to produce the electrode shaft 7.

[0047] The Fig. Figure 3 shows the front end of the sensor electrode 1 with the three electrode pins 2, 3. The two silver electrode pins 2 are directly connected to the conductor structure 50 of one insert 5. The platinum electrode pin 3 is inserted into the adapter sleeve 30, which is electrically and mechanically connected to the conductor structure 50 of the other insert 5. The conductor structure 50 can be located at least partially inside or on the respective insert 5.

[0048] The Fig. Figure 4 shows the assembled components of the electrode shaft 7 to be overmolded. The electrode pins 2 and 3 protrude from the end face and are sealed by the injected plastic. It is clearly evident that the two inserts overlap and are therefore perpendicular to each other.

[0049] In the Fig. Figure 5 shows how, in the illustrated embodiment, a total of six solder points 52 are arranged in a row in the angle between the two inserts 5. The solder points 52 connect the two inserts 5 to each other and serve to stiffen the arrangement of the two inserts 5. The distance between the solder points 52 at the apex of the angle enclosed by the two inserts 5 and the conductor structure 50 further out on the insert 5 is visible. It can be seen below the horizontally extending insert 5 that at least one further row of solder points 52 is present.

[0050] The cropped representation of the Fig. Figure 6 shows that in the four angles of intersection between the two inserts 5, and thus within the four corners, there is a row of solder points 52 in each row. In this case, there are six solder points 52 in each row, so that the two inserts 5 are connected to each other by a total of 24 solder points. Fig. Figure 6 also illustrates how the vertically arranged insert 5 here passes through the center of the horizontally arranged insert 5, resulting in a cross shape. Reference symbol list 1 sensor electrode 2 electrode pins 3 Electrode pen 4 electrode pins 5 inserts 6 Connection component 7 Electrode shaft 8 Sealing component 30 adapter sleeve 50 Management structure 51 recess 52 solder points 60-pin connection component 70 End face of the electrode shaft 71 End face of the electrode shaft 72 Receipt groove of the electrode shaft 100 plugs 101 measuring cell 102 Reaction fluid 103 measuring cell covers QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 42 31 960 A1

[0003] DE 10 2008 054 659 A1

[0005] DE 10 2018 121 787 A1

[0005] DE 10 2017 220 847 A1

[0005] DE 10 2021 112 181 A1

[0005] DE 10 2016 110 856 A1

[0005] Cited non-patent literature

[0000] ISO standard 9562

[0002]

Claims

[1] Sensor electrode (1) for halogen determination, wherein the sensor electrode (1) has at least two electrode pins (2, 3, 4), an elongated, plate-like insert (5), a connection component (6) and an electrode shaft (7), wherein the electrode shaft (7) has two opposing end faces (70, 71), wherein the electrode pins (2, 3, 4) are arranged such that the electrode pins (2, 3, 4) extend beyond one end face (70) of the electrode shaft (7) or are flush with the end face (70), wherein at least one electrode pin (2, 3, 4) is electrically and mechanically connected to the insert (5), wherein the insert (5) is arranged in the electrode shaft (7), wherein the connection component (6) is arranged on the other end face (71) of the electrode shaft (7), wherein the insert (5) is electrically and mechanically connected to the connection component (6), wherein the electrode shaft (7) is at least partially produced by an injection molding process, and wherein the electrode pins (2, 3, 4) are at least partially embedded in the electrode shaft (7). [2] Sensor electrode (1) according to claim 1, wherein the electrode shaft (7) is at least partially made of a plastic. [3] Sensor electrode (1) according to claim 1 or 2, wherein two electrode pins (2) are at least partially made of silver. [4] Sensor electrode (1) according to one of claims 1 to 3, wherein two electrode pins (2) are at least partially made of platinum. [5] Sensor electrode (1) according to one of claims 1 to 4, wherein the sensor electrode (1) further comprises an electrode pin (3) as a cathode pin, preferably consisting at least partially of platinum. [6] Sensor electrode (1) according to any one of claims 1 to 5, wherein the sensor electrode (1) has at least two inserts (5), wherein the two inserts (5) have electrical conductor structures (50), wherein the two electrode pins (2), which are at least partially made of silver, are connected to the electrical conduction structures (50) of one insert (5), and wherein the electrode pin (3), which is at least partially made of platinum, is connected - indirectly or directly - to the electrical conduction structures (50) of the other insert (5). [7] Sensor electrode (1) according to one of claims 1 to 6, wherein an electrode pin (4) serves as a generator anode. [8] Sensor electrode (1) according to one of claims 1 to 7, wherein the connection component (6) is designed such that the connection component (6) allows a reversible electrical connection with a plug (100). [9] Sensor electrode (1) according to one of claims 1 to 8, wherein the electrode shaft (7) further comprises at least one receiving groove (72) for receiving a sealing component (8). [10] Sensor electrode (1) according to any one of claims 1 to 9, wherein the sensor electrode (1) has at least two inserts (5), wherein at least one insert (5) has electrical conduction structures (50), and wherein the inserts (5) are designed and arranged relative to each other such that the planes in which the inserts (5) each mainly extend are substantially perpendicular to each other. [11] Sensor electrode (1) according to claim 10, wherein the inserts (5) are designed and arranged relative to each other such that the inserts (5) together form essentially a T-shape. [12] Sensor electrode (1) according to claim 10, wherein the inserts (5) are designed and arranged relative to each other such that the inserts (5) together essentially form a shape of the plus sign. [13] Sensor electrode (1) according to any one of claims 1 to 12, wherein the sensor electrode (1) has at least two inserts (5), wherein at least one insert (5) has electrical conduction structures (50), and wherein the inserts (5) are designed and arranged relative to each other such that one insert (5) at least partially extends through the other insert (5). [14] Sensor electrode (1) according to claim 13, wherein the at least two inserts (5) are connected to each other via solder points (52). [15] Sensor electrode (1) according to one of claims 1 to 14, wherein at least one electrode pin (2) - and preferably two electrode pins (2) - is connected to the electrical conduction structures (50) of the insert (5) by a soldered connection. [16] Sensor electrode (1) according to any one of claims 1 to 15, wherein at least one electrode pin (3) is resiliently arranged in an adapter sleeve (30) and electrically connected to the adapter sleeve (30), and wherein the adapter sleeve (30) is electrically connected to the electrical conductor structures (50) of the insert (5). [17] Sensor electrode (1) according to claim 16, wherein the electrode pin (3) arranged in the adapter sleeve (30) is inserted into the adapter sleeve (30) and is fixed and sealed as a result of the production of the electrode shaft (7) by the injection molding process. [18] Sensor electrode (1) according to one of claims 1 to 17, wherein the connection component (6) is designed as a multipole socket in the direction of the insert (5). [19] Sensor electrode (1) according to any one of claims 1 to 18, wherein the electrode shaft (7) and the connection component (6) are designed and arranged such that a cross-section of the connection components (6) along the electrode shaft (7) is essentially always symmetrical. [20] Method for producing a sensor electrode (1) for halogen determination, the method comprising at least the following steps: that several electrode pins (2, 3, 4) are arranged relative to each other, that at least one electrode pin (2, 3, 4) with an insert (5) is electrically and mechanically connected that an electrode shaft (7) is produced at least partially by injection molding around the electrode pins (2, 3, 4) and around the insert (5) such that the electrode pins (2, 3, 4) and the insert (5) are at least partially embedded in the electrode shaft (7) and that at least one electrode pin (2, 3, 4) partially projects beyond an end face (70) of the electrode shaft (7), and that after the electrode shaft (7) has been produced, the extent by which at least one electrode pin (2, 3, 4) projects beyond the front face (70) is changed.

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