Method of manufacturing a probe element for a temperature measuring instrument and probe element
By employing a single-junction design with multi-core mineral-insulated metal-sheathed cables in the probe elements of temperature measuring instruments, the problem of uneven thermocouple spacing was solved, achieving the effects of simplified manufacturing and improved mechanical resistance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ENDRESS & HAUSER GMBH & CO KG
- Filing Date
- 2025-11-28
- Publication Date
- 2026-06-05
Smart Images
Figure CN122149665A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a method for manufacturing a probe element for a temperature measuring instrument, and to such a probe element. Background Technology
[0002] Temperature measuring instruments or thermometers for determining and / or monitoring the temperature of a medium are known from the prior art in various embodiments. Thus, there exist thermometers that measure temperature using the expansion of a liquid, gas, or solid with a known coefficient of expansion, or thermometers that measure temperature by relating the electrical conductivity of a material, or a quantity derived therefrom (e.g., resistance when using, for example, a resistive element, or the thermoelectric effect in the case of a thermocouple), to temperature. On the other hand, radiation thermometers, particularly pyrometers, use the thermal radiation of a substance to determine its temperature. The basic measurement principles have been described in various publications.
[0003] In the case of temperature sensors in the form of resistive elements, the so-called thermistors are known. They are also referred to as PTC or NTC thermistors (PTC or NTC is short for positive temperature coefficient or negative temperature coefficient). PTC thermistors are particularly suitable as temperature sensors because their resistance increases linearly with increasing temperature. Platinum is the preferred material and is widely used in PTC thermistors because platinum exhibits a general dependence of resistance on temperature, which is at most quadratic. Resistive elements are typically designed to have a specific nominal resistance at a reference temperature of 0°C and are commercially available as so-called Pt10 (10 Ohm), Pt100 (100 Ohm), and Pt1000 (1k Ohm) resistive elements.
[0004] The resistive element can be embodied as a so-called wound resistance thermometer, or as a layer mounted on a substrate using thin or thick film technology. In the case of thin-film sensors, for example, sensor elements with connecting wires are used and mounted on a carrier substrate, wherein the back side of the carrier substrate typically has a metallic coating.
[0005] However, in the case of temperature sensors in the form of thermocouples, the temperature is determined by the thermoelectric voltage generated between thermocouple wires connected at one end, made of different materials. Thermocouples according to standard IEC 60584-x, such as type R, S, B, J, T, E, K, N, C, and A thermocouples, are commonly used as temperature sensors for temperature measurement. However, other material pairs, such as those with a measurable Seebeck effect, are also possible. This invention relates to the manufacture of thermocouple-based probe elements for temperature measuring instruments.
[0006] Typically, a temperature sensor is arranged in such a probe element, also known as a measuring insert, which includes an elongated tubular member serving as a sheath for the temperature sensor. The sheath contains, for example, an electrically insulating filler, into which at least a portion of the temperature sensor and electrical connection wires for contacting the temperature sensor are embedded. Typically, for example in an insertion thermometer, the measuring insert protrudes into the medium from its distal region to determine the temperature. Thus, the distal region faces and / or is immersed in the medium, while the proximal region (which is opposite the distal region in the longitudinal direction of the measuring insert) faces away from the medium. The elongated tubular member is particularly closed or sealed at the distal region.
[0007] The probe element can be assembled in a protective tube, especially a metal protective tube, such as a thermocouple sheath, which serves as an immersion body. Moreover, the protective tube is usually sealed at its distal end to protect the components (such as the probe element and / or temperature sensor) from the environment to which the thermometer is exposed (such as the medium into which the thermometer is inserted).
[0008] To manufacture probe elements with thermocouples as temperature sensor elements, multi-core mineral-insulated metal-sheathed (MIMS) cables are typically supplied. MIMS cables generally consist of an elongated tubular member with an outer sheath, within which inner conductors (typically 1 to 8) extend, particularly parallel to the cylindrical axis of the outer sheath.
[0009] The outer sheath is typically metallic and can be made of base metals or precious metals or alloys (e.g., stainless steel, nickel-based alloys, copper, etc.). The outer sheath typically has an outer diameter ranging from 0.5 mm to 10.8 mm. The inner conductors are insulated from and from the outer sheath by a compact insulating material, for example, by being pressed into a metal oxide powder (e.g., MgO, Al2O3, SiO2, etc.). Depending on the type of MIMS cable, the inner conductors can have different diameters, and in particular, the outer diameter of the outer sheath. Depending on the type of powder, this can be of varying hygroscopicity and / or compressibility, with different particle sizes, different degrees of dryness, and / or may contain chemically bound (residual) water.
[0010] The internal conductors are made of a combination of different materials, which, when joined together, form the (thermal) junction of a thermocouple due to the thermoelectric effect.
[0011] The junction can be a so-called grounded thermocouple junction, in which the internal conductor or core of the MIMS cable is directly welded to the metal sheath, or the junction can be a so-called ungrounded thermocouple junction, in which the internal conductor or core of the MIMS cable is electrically insulated from the metal sheath.
[0012] When multiple internal conductors are present, a probe element with multiple temperature sensors can be created by joining the multiple conductors to form multiple junctions or thermocouples. Typically, the internal conductors of an elongated tubular member are exposed at their distal ends. The corresponding internal conductors are subsequently joined to form corresponding junctions of the corresponding thermocouples, and the distal ends are closed by caps and / or welded closures, which typically seal the probe element at their distal ends.
[0013] In this case, the (thermal) junction must be positioned such that it is spaced a certain distance from the welded closure. However, manufacturing such probe elements with multiple (e.g., two or three) thermocouples is almost always done manually. Therefore, the distance between the thermal junction and the welded closure is subject to fluctuation and may be non-uniform for all thermal junctions or thermocouples. This can lead to temperature measurement errors when using probe elements manufactured in this way as measuring inserts for temperature measuring instruments. Summary of the Invention
[0014] Therefore, the object of the present invention is to provide a simple method for producing a probe element having multiple thermocouples, wherein the multiple thermocouples are uniformly spaced apart from the distal end, i.e., having the same distance.
[0015] The object of the present invention is achieved by a method for manufacturing a probe element for a temperature measuring instrument, and by means of the probe element.
[0016] Regarding the method, the objective is achieved through a method for manufacturing a probe element for a temperature measuring instrument, the method comprising:
[0017] - Provides an elongated tubular member having a longitudinal axis, the elongated tubular member comprising:
[0018] -- Sheath;
[0019] -- Four or more internal conductors, said four or more internal conductors being arranged inside the sheath,
[0020] An even number of internal conductors are provided, such that the internal conductors are provided in two or more pairs.
[0021] Furthermore, each of the plurality of internal conductors comprises a first pair of component conductors made of a first material and a second pair of component conductors made of a second material, wherein the second material is different from the first material; and
[0022] -- Insulating material, which is disposed inside the sheath, the insulating material serving to at least electrically insulate the internal conductors from each other;
[0023] - The inner conductors of the paired conductors to be joined are exposed at the distal region of the elongated tubular member.
[0024] - The first pair of exposed internal conductors is joined with the second pair of exposed internal conductors to create a first temperature sensor in the form of a thermocouple at the distal region; and
[0025] - The first pair of component conductors of the second pair of exposed internal conductors are joined with the second pair of component conductors of the second pair, thereby creating a second temperature sensor in the form of a thermocouple at the distal region.
[0026] The engagement of the first pair of component conductors and the engagement of the second pair of component conductors are performed together to form a single engagement point having a material bonding connection between all the first and second component conductors of the first and second pairs.
[0027] The probe element is used to insert into a medium, for example, when used as a measuring insert in a temperature measuring instrument, to determine and / or monitor the temperature of the medium with or without an additional protective tube.
[0028] According to the invention, only a single common junction is formed between the inner conductors of the pair. Therefore, all thermocouples are automatically positioned in the same location and thus spaced the same distance from their distal ends formed by the welded closure. The elongated tubular member has, for example, 4, 6, 8, or another even number of inner conductors or cores.
[0029] The solution according to the present invention has the following further advantages:
[0030] - The overall manufacturing process for multiple (thermal) joints is easier, resulting in reduced production time.
[0031] - Because individual (thermal) joints have a larger overall size, resistance to mechanical stress is increased, and
[0032] - Since forming a thermocouple requires only a single welding process, the overall thermal stress is reduced.
[0033] In embodiments of the method, the single joint is formed by a material bond connection created through one of the following:
[0034] - Welding, brazing or soldering processes.
[0035] In embodiments of the method, the individual joint is a material bond connection created by using one of the following welding processes:
[0036] - Resistance spot welding,
[0037] - Arc welding, especially the welding process using tungsten inert gas.
[0038] Advantageously, according to the present invention, more traditional welding techniques can be used. Modern and more complex and / or expensive welding techniques, such as laser welding, are not necessary.
[0039] In an embodiment of the method, the sheath is metallic, and the insulating material is used to insulate the inner conductor from the sheath.
[0040] In embodiments of the method, six or more internal conductors are provided, and the method further includes:
[0041] - The first pair of component conductors of the third pair of exposed internal conductors are joined with the second pair of component conductors of the third pair, thereby creating a third temperature sensor in the form of a thermocouple at the distal region.
[0042] The engagement of the first pair of component conductors, the engagement of the second pair of component conductors, and the engagement of the third pair of component conductors are performed together to form the single engagement point, which has a material bonding connection between all the first component conductors and all the second component conductors of the first, second, and third pairs.
[0043] In embodiments of the method, the elongated tubular member is provided in the form of a multi-core mineral-insulated metal-sheathed cable having an even number of internal conductors.
[0044] In embodiments of the method, the method further includes:
[0045] - The distal end of the sheath is sealed with a welded closure, such that a distal end is generated in the distal region near the single joint point.
[0046] In embodiments of the method, the method further includes:
[0047] - Provide end insulation materials, especially end insulation materials in powder form.
[0048] - Before sealing with the welded closure, press the end insulation material against the individual joint.
[0049] In embodiments of the method, for one or more of the pairs, the first pair of component conductors and the second pair of component conductors are arranged within the elongated tubular member, particularly within a multi-core mineral-insulated metal-sheathed cable, such that, if applicable, the first pair of component conductors is the nearest neighbor of the second pair of component conductors.
[0050] In embodiments of the method, the group comprises the following materials:
[0051] - The first material of the first pair of component conductors of the first pair joined at the single joint point;
[0052] - The second material of the second pair of component conductors of the first pair in the single joint point;
[0053] - The first material of the first pair of component conductors of the second pair joined at the single joint point;
[0054] - The second material of the second pair of component conductors of the second pair joined at the single joint point;
[0055] It includes three or more different materials.
[0056] Regarding the probe element, the objective is achieved by a probe element for a temperature measuring instrument, wherein the probe element is manufactured by a method according to the invention.
[0057] In an embodiment of the probe element, the individual engagement point is spaced apart from the distal end of the probe element in a direction along the longitudinal axis by a distance at least 0.15 times the diameter of the sheath, and particularly at most 5 times the diameter of the sheath.
[0058] In an embodiment of the probe element, the individual junction has a thickness in the direction along the longitudinal axis, the thickness being at least one times the conductor diameter of the inner conductor, wherein, in particular, the thickness is at most a natural multiple of the conductor diameter multiplied by the total number of the inner conductors, preferably four or six.
[0059] In an embodiment of the probe element, the welded closure at the distal end has a thickness in the direction along the longitudinal axis, the thickness being at least 0.1 times the diameter of the sheath, and in particular at most four times the diameter of the sheath.
[0060] In an embodiment of the probe element, the insulating distance provided by the insulating material between the welded closure at the single joint and the distal end has a length in the direction along the longitudinal axis that is at least 0.05 times the diameter of the sheath. Attached Figure Description
[0061] The invention will be explained in more detail with reference to the following non-scaled drawings, wherein the same reference numerals denote the same features. Reference numerals already mentioned may be omitted in subsequent drawings where such clarity is required or where it otherwise appears advantageous.
[0062] The following shows:
[0063] Figure 1a An embodiment of the probe element 100 according to the invention is shown in a schematic cross-sectional view in a plane parallel to the longitudinal axis LA of the elongated tubular member 1;
[0064] Figure 1b It shows along Figure 1a The cross-sectional view of the probe element 100, taken by the dashed line A-A', shows that in this embodiment, there are four internal conductors 31, 32, 33, and 34.
[0065] Figure 1c It shows along Figure 1a The cross-sectional view taken by the dashed line A-A' in the figure shows that, in this embodiment, there are six internal conductors 31, 32, 33, 34, 35, and 36.
[0066] Figure 2 The distal region 10 of the elongated tubular member 1 is shown; and
[0067] Figure 3 A flowchart illustrating the steps of the method according to the invention in one embodiment is shown. Detailed Implementation
[0068] Figure 1a A probe element 100 having an elongated tubular member 1 is shown in an embodiment of the invention. The longitudinal axis LA is, for example, the (primary) axis of inertia of the elongated tubular member 1. The sheath 2 (e.g., a metal sheath 2) includes internal conductors 31, 32, 33, 34; 35, 36 and an insulating material 4 for electrically insulating the internal conductors 31, 32, 33, 34; 35, 36 from each other and from the sheath 2.
[0069] exist Figure 1a In the side view, only three inner conductors 31, 32, and 33 are visible. There are usually an even number of inner conductors, such as four inner conductors 31, 32, 33, and 34 (see [reference]). Figure 1b ) or six internal conductors 31, 32, 33, 34, 35, 36 (see Figure 1c (or even more.)
[0070] The elongated tubular member 1 is provided herein in the form of a multi-core mineral-insulated metal-sheathed cable (MIMS), wherein an even number of cores are selected to provide pairs 3a, 3b, and 3c of internal conductors 31, 32, 33, 34; 35, 36. Each pair 3a, 3b, and 3c has a first pair of member conductors 31, 33, and 35 of a corresponding first material and a second pair of member conductors 32, 34, and 36 of a corresponding second material different from the first material. The first material of all first pair member conductors 31, 33, and 35 may or may not be different from each other, and the same applies to the second material of all second member conductors 32, 34, and 36.
[0071] The corresponding first and second materials for each pair 3a, 3b, 3c are selected such that, when electrically connected, a measurable thermoelectric effect or Seebeck effect exists between the first pair of component conductors and the second pair of component conductors. Therefore, the internal conductors 31, 32, 33, 34, 35, 36 of each pair form the connecting wires for forming the first, second, and (if applicable) third temperature sensors 5a, 5b, 5c in the form of thermocouples, and the probe element 100 can be used in a temperature measuring instrument. These pairs 3a, 3b, 3c of the internal conductors 31, 32, 33, 34, 35, 36 in… Figure 1b and Figure 1c The cases shown include adjacent neighbors.
[0072] When probe element 100 is used in the temperature measuring instrument, the corresponding conductors 31, 32, 33, 34; 35, 36 are wired to an electronic unit with operating circuitry. Conductors 31, 32, 33, 34; 35, 36 are wired in such a manner that, for each of the pairs 3a, 3b; 3c, the operating circuitry is implemented to acquire the thermoelectric voltage between the first pair of component conductors and the second pair of component conductors. Therefore, for each of the temperature sensors 5a, 5b; 5c, the corresponding thermoelectric voltage acquired by the electronic unit serves as a measurement signal, which can be used to determine the measured temperature present at a single junction 6, representing the common location of the corresponding temperature sensors 5a, 5b; 5c.
[0073] At the distal region 10 of the elongated tubular member 1, all pairs 3a, 3b, and 3c are joined together in a single junction 6. This single junction 6 defines a common location for all temperature sensors 5a, 5b, and 5c. A welded closure 7 closes the single junction 6, wherein additional end insulation material 9 is provided in the distal region 10. The outermost distal end 8 is formed by the welded closure 7, which seals the sheath 2 at the distal region 10 of the elongated tubular member 1.
[0074] Figure 2A more detailed view of the distal region 10 is shown. A single junction 6 defining the common location of all thermocouple temperature sensors 5a, 5b; 5c has a junction thickness jd in the direction of the longitudinal axis LA, which is at least twice the conductor diameter d2 (i.e., the diameter of the inner conductors 31, 32, 33, 34; 35, 36). The upper limit of the junction thickness jd is then generally determined by the number of inner conductors 31, 32, 33, 34; 35, 36 and their conductor diameter d2.
[0075] Since junction 6 comprises all pairs 3a, 3b, and 3c that form thermocouple temperature sensors 5a, 5b, and 5c, a single junction 6 has a larger overall size and a correspondingly increased resistance to mechanical stress compared to several individual junctions that are individually joined for each pair 3a, 3b, and 3b.
[0076] For example, the end insulation material 9 is provided in powder form, which is pressed against a single joint 6 in an amount selected to achieve a specific insulation distance id. The insulation distance id is typically a length corresponding to at least 0.05 times the sheath diameter d1 of the sheath 2 in the direction along the longitudinal axis LA.
[0077] The welded closure 7 forming the distal end 8 has a weld thickness wd that is at least 0.1 times the diameter d1 of the (outer) sheath. The insulation distance id and the weld thickness wd together constitute the total spacing sd between the single joint 6 and the distal end 8 in the direction along the longitudinal axis LA. Therefore, the spacing sd is at least 0.15 times the diameter d1 of the sheath.
[0078] Figure 3 Finally, a flowchart of the steps of the method according to the present invention is shown.
[0079] In step A), for example, an elongated tubular member 1 is provided in the form of a multi-core mineral-insulated metal-sheathed (MIMS) cable.
[0080] In step B), pairs 3a, 3b, and 3c of the internal conductors 31, 32, 33, 34; 35, 36 to be joined are exposed at the distal region 10.
[0081] In step C), for example, a single joint point 6 is formed between all the internal conductors 31, 32, 33, 34, 35, 36 to be joined by welding the internal conductors 31, 32, 33, 34, 35, 36 together, and the single joint point 6 is formed as a weld joint. Therefore, all temperature sensors 5a, 5b, 5c are substantially located in the same position. Thus, for a temperature measuring instrument having a probe element 100 manufactured according to the invention, wherein the probe element 100 has two or three thermocouple temperature sensors 5a, 5b, 5c, there is no or no spatial offset between the plurality of temperature sensors 5a, 5b, 5c, particularly with respect to spatial offset in the longitudinal position along the longitudinal axis LA.
[0082] In contrast, when several individual joints are formed, i.e., each of the pairs 3a; 3b; 3c forms one joint, it is particularly difficult for technicians employing manual and therefore error-prone welding processes to ensure a uniform spacing sd between the individual thermal joints and the distal end 8. When such a probe element 100 is used in a temperature measuring instrument as described above, the uneven spacing sd between the multiple thermal joints can subsequently lead to systematic errors in temperature determination.
[0083] Furthermore, since only a single common welding process is required to create a single common joint, stresses originating from the manufacturing process (especially thermal stress) are minimized. Moreover, conventional welding techniques, such as resistance spot welding or arc welding, can be used, for example, by using tungsten inert gas welding (also known as TIG welding). More complex welding techniques, such as laser welding, which would be necessary when creating several individual joints, are not required.
[0084] Finally, in step D), before sealing the individual joint 6 with the welded closure 7, an end insulating material 9, for example using powder as the source material, is pressed against the individual joint 6, thereby creating the outermost distal end 8 of the probe element 100. Similarly, a cap element welded to the sheath 2 can also be used.
[0085] The method according to the invention provides a very simple method for manufacturing probe elements 100 for temperature measuring instruments, wherein all temperature sensors 5a, 5b, 5c maintain the same spacing distance sd from a single junction 6 to the distal end 8 in a simple and safe manner. Therefore, for all temperature sensors 5a, 5b, 5c, it can be easily ensured that the spacing distance sd of the single junction 6 is sufficiently high, i.e., the spacing distance sd is greater than a certain required minimum value.
[0086] Figure Labels
[0087] 100 probe elements
[0088] 1. Slender tubular component
[0089] 10 remote areas
[0090] 2 sheaths
[0091] 31, 32, 33, 34, 35, 36… Internal conductors
[0092] 3a, 3b, 3c... internal conductor pairs
[0093] 4. Insulation materials
[0094] 5a, 5b, 5c... Temperature sensors
[0095] 6 single joints
[0096] 7 Welded enclosures
[0097] 8 distal end
[0098] 9. Terminal insulation material
[0099] LA longitudinal axis
[0100] d1 sheath diameter
[0101] d2 conductor diameter
[0102] JD joint thickness
[0103] id insulation distance
[0104] sd interval distance
[0105] WD welding thickness
Claims
1. A method for manufacturing a probe element (100) for a temperature measuring instrument, the method comprising: - Provides an elongated tubular member (1) having a longitudinal axis (LA), the elongated tubular member (1) comprising: -- Sheath (2); -- Four or more internal conductors (31, 32, 33, 34), said four or more internal conductors (31, 32, 33, 34) are arranged inside the sheath (2), An even number of internal conductors (31, 32, 33, 34) are provided such that the internal conductors (31, 32, 33, 34) are provided in two or more pairs (3a, 3b). Furthermore, each pair (3a, 3b) of the plurality of internal conductors (31, 32, 33, 34) comprises a first pair of component conductors (31, 33) made of a first material and a second pair of component conductors (32, 34) made of a second material, wherein the second material is different from the first material; and -- Insulating material (4), which is disposed inside the sheath (2) and is used to at least electrically insulate the internal conductors (31, 32, 33, 34) from each other; - The inner conductors (31, 32, 33, 34) of the pair of conductors to be joined are exposed at the distal region (10) of the elongated tubular member (1). - The first pair of component conductors (31) of the first pair (3a) of the exposed internal conductors (31, 32, 33, 34) is joined with the second pair of component conductors (32) of the first pair (3a), thereby creating a first temperature sensor (5a) in the form of a thermocouple at the distal region (10); and - The first pair of component conductors (33) of the second pair (3b) of the exposed internal conductors (31, 32, 33, 34) is joined with the second pair of component conductors (34) of the second pair (3b) to generate a second temperature sensor (5b) in the form of a thermocouple at the distal region (10). The engagement of the first pair of component conductors (31, 32) and the engagement of the second pair of component conductors (33, 34) are performed together to form a single engagement point (6) having a material bond connection between all the first component conductors (31, 33) and the second component conductors (32, 34) of the first pair (3a) and the second pair (3b).
2. The method according to claim 1, wherein, The individual joint (6) is a material bond connection created by one of the following: - Welding, brazing or soldering processes.
3. The method according to claim 2, wherein, The individual joint (6) is a material bonding connection produced by using one of the following welding processes: - Resistance spot welding, - Arc welding, especially the welding process using tungsten inert gas.
4. The method according to at least one of the preceding claims, in, The sheath (2) is metallic, and the insulating material (4) is used to insulate the inner conductors (31, 32, 33, 34) from the sheath (2).
5. The method according to at least one of the preceding claims, in, Providing six or more internal conductors (31, 32, 33, 34, 35, 36), and the method further includes: - The first pair of component conductors (35) of the third pair (3c) of the exposed internal conductors (31, 32, 33, 34, 35, 36) is joined with the second pair of component conductors (36) of the third pair (3c) to generate a third temperature sensor (5c) in the form of a thermocouple at the distal region (10). The engagement of the first pair of component conductors (31, 32), the engagement of the second pair of component conductors (33, 34), and the engagement of the third pair of component conductors (35, 36) are performed together to form the single engagement point (6), which has a material bond connection between all the first component conductors (31, 33, 35) of the first pair (3a), the second pair (3b), and the third pair (3c) and all the second component conductors (32, 34, 36).
6. The method according to at least one of the preceding claims, in, The elongated tubular member (1) is provided in the form of a multi-core mineral-insulated metal-sheathed cable (MIMS) with an even number of internal conductors.
7. The method according to at least one of the preceding claims, further comprising: - The distal end of the sheath (2) is sealed with a welded closure (7) such that a distal end (8) is generated in the distal region (10) near the single joint (6).
8. The method according to claim 7, further comprising: - Provide end insulation material (9), especially end insulation material in powder form (9) - Before sealing with the welded closure (7), press the end insulation material (9) against the single joint (6).
9. The method according to at least one of the preceding claims, in, For one or more of the pairs (3a; 3b; 3c), the first pair of component conductors (31; 33; 35) and the second pair of component conductors (32; 34; 36) are arranged within the elongated tubular member (1), particularly within a multi-core mineral-insulated metal-sheathed cable, such that, if applicable, the first pair of component conductors (31; 33; 35) is the nearest neighbor of the second pair of component conductors (32; 34; 36).
10. The method according to at least one of the preceding claims, in, The group includes the following materials: - The first material of the first pair of component conductors (31) of the first pair (3a) joined in the single joint point (6); - The second material of the second pair of component conductors (32) of the first pair (3a) in the single joint point (6); - The first material of the first pair of component conductors (33) of the second pair (3b) joined in the single joint point (6); - The second material of the second pair of component conductors (34) of the second pair (3b) joined in the single joint point (6); It includes three or more different materials.
11. A probe element (100) for a temperature measuring instrument, wherein, The probe element (100) is produced by the method according to at least one of the preceding claims.
12. The probe element (100) according to claim 11. in, The individual engagement point (6) is spaced apart from the distal end (8) of the probe element (100) in the direction along the longitudinal axis (LA) by a spacing distance (sd) that is at least 0.15 times the sheath diameter (d1) of the sheath (2), and in particular at most 5 times the sheath diameter (d1).
13. The probe element (100) according to claim 11 or 12. in, The individual junction (6) has a thickness (jd) in the direction along the longitudinal axis (LA), the thickness (jd) being at least one times the conductor diameter (d2) of the inner conductors (31; 32; 33; 34; 35; 36). Furthermore, in particular, the thickness (jd) is at most a natural multiple of the conductor diameter (d2) multiplied by the total number of the inner conductors (31; 32; 33; 34; 35; 36), preferably four or six.
14. The probe element (100) according to any one of claims 11 to 13. in, The welded closure (7) at the distal end (8) has a thickness (wd) in the direction along the longitudinal axis (LA), the thickness (wd) being at least 0.10 times the sheath diameter (d1) of the sheath (2), and in particular at most four times the sheath diameter (d1).
15. The probe element (100) according to any one of claims 11 to 14. in, The insulation distance (id) provided by the end insulation material (9) between the welded closure (7) at the single joint (6) and the distal end (8) has a length in the direction along the longitudinal axis (LA) that is at least 0.05 times the sheath diameter (d1) of the sheath (2).