SE544289C2

SE544289C2 - Magnetic field sensor having a marking, and method for producing a magnetic field sensor

Info

Publication number: SE544289C2
Application number: SE2150170A
Authority: SE
Inventors: Karl Frosch; Klaus Hug; Torsten Wahler
Original assignee: Continental Automotive Gmbh
Priority date: 2020-03-02
Filing date: 2021-02-16
Publication date: 2022-03-29
Also published as: DE102020202668B4; DE102020202668A1; FR3107770A1; SE2150170A1

Abstract

Magnetic field sensor having a marking, and method for producing a magnetic field sensorThe invention relates to a magnetic field sensor having a device housing 1 which has at least a first housing part (2) and a second housing part (4) closing the first housing part (2), wherein the first housing part (2) and the second housing part (4) are joined and are connected by means of a nonreleasable jointed connection (6). To increase the protection of the magnetic field sensor from possible manipulations, it is proposed that a housing outer side (8) of the device housing 1 has a graphic marking (10) in the region of the jointed connection (6), wherein the first housing part (2) has a first marking part (20) of the marking (10), and the second housing part (4) has a second marking part (22) of the marking (10) that graphically matches up with the first marking part (20), and wherein the two marking parts (20), (22) transition seamlessly into one another. In addition, the invention relates to a method for producing such a magnetic field sensor.

Description

Description Magnetic field sensor having a marking, and method for producing a magnetic field sensor id="p-1"

[0001] The invention relates to a magnetic field sensorhaving a device housing which has at least a first housingpart and a second housing part closing the first housing part,wherein the first housing part and the second housing part arejoined and are connected by means of a nonreleasable jointedconnection. In addition, the invention relates to a method for producing an aforementioned magnetic field sensor. id="p-2"

[0002] Such a magnetic field sensor is known for example asa so-called speed sensor or rotary encoder for a tachograph ina. motor vehicle, in particular a commercial vehicle. Themagnetic field sensor has a sensor head and is, for example,screwed into, for example, a transmission housing of atransmission of the motor vehicle or fastened for example inthe vicinity' of a rotating component which rotatescorrespondingly to a driving speed of the motor vehicle. Themagnetic field sensor uses the sensor head to detect a movementof a transmission gearwheel of the transmission or a movementof the rotating component. The movement of the transmissiongearwheel is a measure of the speed of the motor vehicle. Apart of a first housing part of a device housing of the magnetic field sensor is a constituent part of the sensor head. id="p-3"

[0003] The first housing part is closed by a second housingpart of the device housing, with the second housing part havingconnection contacts by means of which the magnetic field sensoris connected to the tachograph of the motor vehicle. In orderto protect components of the magnetic field sensor that arearranged in the device housing both from environmental influences and from unauthorized external access, the first housing part and the second housing part are connected by meansof a nonreleasable jointed connection. Given the required highdegree of reliability of data recorded by the tachograph, itis of importance, inter alia, to avoid a manipulation of themagnetic field sensor and, resulting from such a manipulation, data adulterations. id="p-4"

[0004] It is an object of the invention to provide a magneticfield sensor of the type stated at the outset that has a highdegree of security against manipulation. It is additionally anobject of the invention to specify a method for producing amagnetic field sensor having a high degree of security against manipulation. id="p-5"

[0005] The first-mentioned object is achieved according tothe invention. in that a 'housing' outer* side of the devicehousing has a graphic marking in the region of the jointedconnection, wherein the first housing part has a first markingpart of the marking, and the second housing part has a secondmarking part of the marking that graphically matches up withthe first marking part, and wherein the two marking parts transition seamlessly into one another. id="p-6"

[0006] Of particular advantage in the magnetic field sensoraccording to the invention is the seamless transitioning intoone another of the two marking parts of the first housing partand of the second housing part. The two marking partsgraphically match up and thus afford for example an image orfor example a line structure or for example a pattern or forexample a decoration. The marking extends over and beyond aboundary region, for example a parting line, between the first housing part and the second housing part. id="p-7"

[0007] The marking can have a plurality of marking segments extending over and beyond the boundary region between the first housing part and the second housing part. These markingsegments then each have a corresponding aforementioned firstmarking part and a corresponding aforementioned second markingpart, wherein the first and second marking part in each case,that is to say for each marking segment, match up graphically and transition seamlessly into one another. id="p-8"

[0008] The fact that the housing outer side of the devicehousing has the graphic marking in the region of the jointedconnection means that the graphic marking is situated in thejointed connection or that it is arranged directly adjoiningthe jointed connection or that it is arranged parallel to thejointed connection and thus at the level of the jointed connection. id="p-9"

[0009] If, with manipulative intent, for example to exchangea circuit board of the magnetic field sensor that is arrangedin the device housing, the device housing is for example cutopen by means of a thin saw blade at a parting line betweenthe first housing part and the second housing part and joinedtogether again after the circuit board has been removed andexchanged, there occurs an at least minimum offset between thefirst marking part and second marking part. The first markingpart and the second marking part thus no longer transitionseamlessly into one another, and the marking is disturbed ina manner which can be discerned optically, for example by meansof a magnifying glass. The manipulation that has taken placethus remains permanently discernible. For example, it istherefore not possible for the device housing to be sawn open,for example with a thin saw cut, without leaving behindpermanently visible changes on the device housing.Consequently, reliable manipulation protection is ensured by means of the invention. id="p-10"

[0010] It is conceivable for example to apply the marking tothe first housing part and the second housing part by means ofa coating method. Such a coating method can for examplecomprise hot stamping, pad printing, silkscreen printing orinkjet printing. By contrast, for simple production of themarking and particularly good durability of the marking, it isparticularly advantageous if, according to one development ofthe invention, the marking' is incorporated. into the firsthousing part and into the second housing part by means of alaser method. Such a laser method involves no ink being appliedto the device housing, but what occurs for example is a removalof material or for example a chemical transformation of thematerial at the surface of the device housing. The removal ofmaterial or the transformation of the material can preferablybe associated with a color change, thereby making it stillmore difficult to conceal a manipulation. There isadvantageously also no way open of removing, for example bymeans of solvents, the graphic marking incorporated by meansof the laser method and of reapplying it following a manipulation of the device housing. id="p-11"

[0011] According to another advantageous development of theinvention, the marking has at least one first line running ata first acute angle over a parting line between the firsthousing part and the second housing part. This line thus runsobliquely over the parting line between the first housing partand. the second. housing' part. As a result, a line offsetmanifests itself particularly clearly at the parting line aftercutting open and reassembling the device housing and is thus even more easily discernible. id="p-12"

[0012] Such discernibility' is additionally' still furtherimproved, and hence the manipulation protection additionallyincreased, if, according to one advantageous development of the invention, the marking has at least one second line running at a second acute angle over the parting line between the firsthousing part and the second housing part, wherein the second acute angle differs from the first acute angle. id="p-13"

[0013] According to another advantageous development of theinvention, the marking' extends over the most part of thecircumference of the device housing. The marking thus extendsover more than half the circumference of the device housing.In this way there is obtained.a particularly large-area markingwithin which, further improving the manipulation protection, possible disturbances are particularly easily discernible. id="p-14"

[0014] According to another advantageous development of theinvention, the marking contains a 2D code. The 2D code extendsover and beyond the parting line between the first housingpart and second housing part. The 2D code can in particular bean optically readable code. The 2D code is preferably a datamatrix code (DMC). If, during a manipulative opening of thedevice housing, such a 2D code is cut open and then joinedtogether again, individual pixels or even complete data rowsare absent in the code, with the result that disturbance-freereading of the code is no longer possible. The graphic markingcan contain one or more aforementioned 2D codes. The 2D codecan for example contain individual data information by meansof which the magnetic field sensor is individualized, with theresult that the magnetic field sensor is clearly identifiable by way of the 2D code. id="p-15"

[0015] An additional increase in the security and in themanipulation. protection. can advantageouslyf be achieved. if,according to one development of the invention, the magneticfield sensor contains a data memory and if the 2D code, inparticular the data matrix code, contains data informationcorresponding to data information stored in the data memory.

In this way, a simple comparison of the data information of the 2D code with the data information stored in the data memorycan provide information on a manipulation of the housing of the magnetic field sensor. id="p-16"

[0016] It would be possible for example to conceive that thedevice housing is a metal housing or that, for example, one ofthe two housing parts is a nætal component and the otherhousing part is a plastics component. By contrast, for simpleand cost-effective nmnufacturability of the nmgnetic fieldsensor, it is particularly advantageous if, according toanother development of the invention, the first housing partand the second housing part each consist of a, preferablyidentical, plastics material. Here, the first housing part andthe second housing part are in each case a plastics component.The plastics material of the first housing part and/or of thesecond housing part can preferably contain glass fibers to increase the strength, for example a proportion of 30%. id="p-17"

[0017] It would be possible for example to conceive that thejointed. connection. is an adhesively' bonded. connection. Bycontrast, for a jointed connection that is particularlyreliable, durable and in particular can also be readilyproduced in large series manufacturing, it is advantageous if,according to one development of the invention, the jointedconnection ii; a pressure-welding connection. The pressure-welding connection can advantageously be an ultrasonic-welding connection. id="p-18"

[0018] The aforementioned second object is achievedaccording' to the invention. with. a method. for producing amagnetic field sensor, wherein a first housing part and asecond housing part of a device housing of the magnetic fieldsensor are joined and are connected by means of a nonreleasablejointed connection. The method is also distinguished by the fact that a housing' outer side of the device housing is provided with a graphic marking in such a way that the firsthousing part is provided with a first marking part of themarking, and the second housing part is provided with a secondmarking part of the marking, to be precise in such a way thatthe first marking part and the second marking part graphicallymatch up and in such a way that the two marking parts transitionseamlessly' into one another. The method according' to theinvention is particularly suitable for producing a magneticfield sensor according to the invention. The first housingpart and the second housing part are preferably pressure- welded, in particular ultrasonically welded. id="p-19"

[0019] It is conceivable for example that the housing outerside is provided with a graphic marking as a result of themarking being applied to the housing outer side by means of acoating method. By contrast, it is particularly advantageousif the housing outer side is provided with the marking by meansof a laser method. Here, the marking is incorporated into thedevice housing on its housing outer side. There occurs forexample a removal of material or for example a chemicaltransformation of the material on the surface of the device housing. id="p-20"

[0020] It would be possible for example to conceive that, ina single method step, the housing outer side is provided withthe marking over the most part of the circumference, inparticular even over the whole circumference, of the devicehousing. By contrast, for precise and cost-effectiveproduction of the magnetic field sensor, it is advantageous ifthe housing outer side is provided with the marking over aportion of a circumference of the device housing. The portionof the circumference of the device housing is preferably less than half the circumference of the device housing. id="p-21"

[0021] In a comparatively simple and cost-effective method,the housing outer side can advantageously be provided with alarge marking, thus offering increased manipulationprotection, if first the housing outer side is provided witha first marking segment of the marking that extends over afirst portion of the circumference of the device housing, ifthen the magnetic field sensor is rotated, for examplecounterclockwise, through a specified angle about alongitudinal axis of the device housing, and. if then thehousing outer side is provided with a second marking segmentof the nmrking that extends over a second portion of thecircumference of the device housing. The first and. secondmarking segment are preferably situated next to one another on the circumference of the device housing. id="p-22"

[0022] It is particularly advantageous if the magnetic fieldsensor is also rotated, for example counterclockwise, througha second specified angle about the longitudinal axis of thedevice housing, and if then the housing outer side is providedwith a third marking segment of the marking that extends overa third portion of the circumference of the device housing. Itis thus possible in a simple manner for at least virtually thewhole circumference of the device housing to be provided withthe marking. The second and third marking segment arepreferably situated next to one another on the circumference of the device housing. id="p-23"

[0023] The invention also includes developments of themethod. according' to the invention. having' features as havealready been described in connection with the developments ofthe magnetic field sensor according to the invention, and viceversa. For this reason, the corresponding developments of the method according to the invention are not described here again. id="p-24"

[0024] The invention also encompasses the combinations of the features of the described embodiments. id="p-25"

[0025] Exemplary embodiments of the invention will be described in more detail below on the basis of the diagrammatic and schematic illustrations in the drawing, in which: Fig. l shows a detail of a device housing of a magnetic fieldsensor in a perspective view, Fig. 2 shows a detail of a graphic marking of the devicehousing according to fig. l, Fig. 3 shows a view of the device housing according to fig.l from above, Fig. 4 shows a first side view of the device housingaccording to fig. l, Fig. 5 shows a second side view of the device housingaccording to fig. l, and Fig. 6 shows a third side view of the device housing according to fig. l. id="p-26"

[0026] In. all of the figures, corresponding' elements are provided with the same reference signs. id="p-27"

[0027] Figure l is a perspective side view showing a detailof a device housing l of a magnetic field sensor. The devicehousing l has a first housing part 2 which takes the form ofa housing pot (see figure 4), and a second housing part 4 whichcloses the first housing part 2 and takes the form of a housingcover. In this exemplary embodiment, the first housing part 2and the second housing part 4 jointly form the device housing l. id="p-28"

[0028] In this exemplary embodiment, both the first housingpart 2 and the second housing part 4 consist of a plasticsmaterial and. are preferably injection-molded. plastics components. The plastics material of the first housing part 2 and of the second housing part 4 can be supplemented with glass fibers to increase the strength. id="p-29"

[0029] The first housing part 2 and the second housing part4 are joined and are connected by means of a nonreleasablejointed connection 6. In the exemplary embodiment shown here,the first housing part 2 and the second housing part 4 arejoined in the direction of a longitudinal axis L of the devicehousing 1. Furthermore, the jointed connection 6 is here apressure-welding connection. In one specific exemplaryembodiment, it can i11 particular* be an ultrasonic-welding connection. id="p-30"

[0030] A housing outer side 8 of the device housing 1 of themagnetic field sensor has a graphic marking 10 in the regionof the jointed connection 6. Here, the graphic marking 10 hasa first marking segment 16, a second marking segment 14 and athird marking segment 12, which marking segments 12, 14, 16each display a line pattern. In addition, the graphic marking10 here has a further, fourth marking segment 18 which displaysa 2D code (see figure 6). The 2D code can in particular be a data matrix code (DMC). id="p-31"

[0031] The first housing part 2 of the device housing 1 hasa first marking part 20 of the marking 10, and the secondhousing part 4 has a second marking part 22 of the marking 10that graphically matches up with the first marking part 20.The two marking parts 20, 22 transition seamlessly into oneanother. This is demonstrated for example by the fact that theline patterns of the three first-mentioned marking segments12, 14, 16 are undisturbed at the transition across a partingline 24 between the first housing part 2 and the second housingpart 4. The marking 10 extends over and beyond the partingline 24. ll id="p-32"

[0032] The aforementioned four marking segments 12, 14, 16,18 each have an above-described first marking part 20 belongingto the first housing part 2 and each have an above-describedsecond marking part 22 belonging to the second housing part 4.The respective first and second marking parts 20, 22 eachextend over and beyond the parting line 24, each match upgraphically and each transition seamlessly into one another (cf. figures 4 to 6). id="p-33"

[0033] In a first exemplary embodiment, the marking 10 canbe applied to the housing outer side 8 of the device housing1 by means of a coating method, for example. By contrast, inthe exemplary embodiment illustrated here, the marking 10 isincorporated by means of a laser method into the first housingpart 2 and into the second housing part 4 on the housing outer side 8 of the device housing 1. id="p-34"

[0034] The design of the marking 10 will be explained inmore detail below by way of figure 2. Figure 2 shows by way ofexample the second marking segment 14 of the graphic marking10 of the device housing from figure 1. The second markingsegment 14 displays a line pattern, and it can be seen thatthe marking 10 has a first line 26 running at a first acuteangle d over the parting line 24 between the first housingpart 2 and the second housing part 4. Furthermore, it can beseen that the marking 10 additionally has a second line 28running at a second acute angle 8 over the parting line 24between the first housing part 2 and the second housing part4, wherein the second acute angle 8 differs from the firstacute angle d. In this exemplary embodiment, the second acuteangle 8 is larger than the first acute angle d. The first acuteangle d is the angle between the parting line 24 and the firstline 26, and the second acute angle 8 is the angle between theparting line 24 and the second line 28. For example, even in the case of the device housing 1 being cut open at the parting l2 line 24, what results after rejoining the first housing part2 and second housing part 4 is an optically discernible lineoffset in the line patterns of the first three marking segments l2, l4, lö. id="p-35"

[0035] A view of the device housing l from above is shown infigure 3. It can be seen that the device housing l of themagnetic field sensor in this exemplary embodimentadditionally has a cable inlet 30 at the first housing part 2(see figure 6). The cable inlet 30 serves for electricallyconnecting electronic components of the magnetic field sensorthat are arranged in the device housing l to, for example, atachograph of a motor vehicle. For example, a connecting cableleading to the tachograph is introduced through the cable inlet30 into the device housing l and electrically connected to a circuit board arranged in the device housing l. id="p-36"

[0036] The circuit board bears a sensor element, for examplea Hall element. The sensor element and possibly an associatedmagnet arranged on the circuit board is arranged in a sensorhead 32 of the magnetic field sensor, which magnetic fieldsensor can also be referred to as an inductive sensor. A partof the first housing part 2 of the device housing l, namelyhere a pot-shaped end portion of the first housing part 2, isa constituent part of the sensor' head. 32 (see figure 6).Furthermore, the first housing part 2 has a connection element34 for fastening the magnetic field sensor to, for example, amotor vehicle. The connection element 34 has for example a half-width b of approximately 15 mm. id="p-37"

[0037] In one exemplary embodiment, the circuit board (notshown here) arranged in the device housing l has a data memory.The data memory contains data information, which data information is stored in the data memory and which corresponds 13 with data information belonging to the 2D code displayed bythe fourth marking segment 18. id="p-38"

[0038] Figure 4 shows a first side view of the device housing1 from direction A according to figure 3, with this directionA and the connection element 34 enclosing, for example, anangle V1 of approximately 60°. Figure 5 shows a second sideview of the device housing 1 from direction B according tofigure 3, with this direction B and the aforementioneddirection A enclosing, for example, an angle V2 ofapproximately 90°, and this direction B and a center axis ofthe connection element 34 enclosing, for example, an angle V4of approximately 30°, and figure 6 shows a third side viewfrom direction C according to figure 3, with this direction Cand the aforementioned direction B enclosing, for example, an angle V3 of approximately 90°. id="p-39"

[0039] A height h of the marking 10 and of the four markingsegments 12, 14, 16, 18 is, for example, approximately 8 mm.The third marking segment 12 and the fourth marking segment 18together have, for example, a length l1 of approximately 25mm. The second marking segment 14 has, for example, a length12 of approximately 17 mm. The first marking segment 16 has,for example, a length l3 of approximately 28 mm. It can beseen from figures 4, 5 and 6 that the marking 10 extends overthe most part of the circumference, namely over more than half the circumference, of the device housing 1. id="p-40"

[0040] During the production of the magnetic field sensor,the housing outer side 8 can, in one exemplary embodiment,first be provided with the first marking segment 16 of themarking 10 that extends over a first portion of thecircumference of the device housing 10, then the magnetic fieldsensor can be rotated counterclockwise through an angle V2 of approximately 90° about the longitudinal axis L of the device 14 housing 1, and then the housing outer side 8 can be providedwith the second marking segment 14 of the marking 10 thatextends over a second portion of the circumference of thedevice housing' 1. Next, the magnetic field. sensor can berotated counterclockwise through a second angle V3 ofapproximately 90° about the longitudinal axis L of the devicehousing 1 and then the housing outer side 8 can be providedwith a third marking segment 12 that extends over a thirdportion of the circumference of the device housing 1, whichthird marking segment can, where appropriate, be supplementedby a fourth marking segment 18 that can likewise extend in the third portion of the circumference of the device housing 1. id="p-41"

[0041] Correspondingly dividing the marking 10 into thethree marking segments 16, 14, 12 allows simplified productionof the magnetic field sensor to be achieved. With reference tofigures 3 to 6, in the exemplary embodiment shown here, it isthus for example the case that first of all the first markingsegment 16 is incorporated into the device housing 1 fromdirection A. Then, the magnetic field sensor is rotatedcounterclockwise through 90° (angle V2) about the longitudinalaxis L of the device housing 1, and this is followed by thesecond marking segment 14 being incorporated into the devicehousing 1 from direction B (with respect to the correspondingregion of the housing outer side 8 that is to be provided withthe further marking segment). Next, the magnetic field sensoris rotated counterclockwise through an additional 90° (angleV3) about the longitudinal axis L of the device housing 1.Finally, the third marking segment 12 is incorporated, togetherwith the fourth marking segment 18, into the device housing 1from direction C (with respect to the corresponding region ofthe housing outer side 8 that is to be provided with the further marking segments). id="p-42"

[0042] Consequently, the first marking segment 16, thesecond marking segment 14 and the third marking segment 12(together with the fourth marking segment 14) each form per sea closed-off unit. Nevertheless, they jointly form the graphicmarking 10 when incorporated into the device housing 1 in threeseparate, preferably successive, method steps. Thisconstitutes a potential simplification of the production ofthe magnetic field sensor, in particular a possibility of costreduction with a simultaneous increase in process reliability,as compared with incorporating the marking 10 into the device housing 1 in a single method step. id="p-43"

[0043] The invention. advantageously' makes it possible toachieve the goal of preventing nonvisible opening of the devicehousing 1. In the case for example of the device housing 1being cut open at the parting line 24 by means of a planar andnarrow (saw) cut and thus of the first housing part 2 beingseparated from the second housing part 4, the marking 10 isdamaged in such a way that the line patterns displayed in thefirst three marking segments 12, 14, 16 have an offset at theparting line 24 during subsequent rejoining' of the firsthousing part 2 and second housing part 4. The 2D code displayedin the fourth marking segment 18 is moreover damaged duringcutting in such a way that data information of the 2D code isdamaged and/or absent during subsequent rejoining. Amanipulation. attempt by' opening' the device housing' of themagnetic field sensor is thus simple to detect optically bothfor example by means of a magnifying glass and by reading the data information of the 2D code.

Claims

Patent claims

1. A magnetic field sensor having a device housing (1) whichhas at least a first housing part (2) and a second housingpart (4) closing the first housing part (2), wherein the firsthousing part (2) and the second housing part (4) are joinedand are connected by means of a nonreleasable jointedconnection (6), characterized in that a housing outer side (8)of the device housing (1) has a graphic marking (10) in theregion of the jointed connection (6), wherein the first housingpart (2) has a first marking part (20) of the marking (10),and the second housing part (4) has a second marking part (22)of the marking (10) that graphically matches up with the firstmarking part (20), and wherein the two marking parts (20, 22) transition seamlessly into one another.

2. The magnetic field sensor as claimed in claim 1,characterized in that the marking (10) is incorporated intothe first housing part (2) and into the second housing part (4) by means of a laser method.

3. The magnetic field sensor as claimed in claim 1 or 2,characterized in that the marking (10) has at least one firstline (26) running at a first acute angle (d) over a partingline (24) between the first housing part (2) and the secondhousing part (4).

4. The magnetic field sensor as claimed in claim 3,characterized in that the marking (10) has at least one secondline (28) running at a second acute angle (ß) over the partingline (24) between the first housing part (2) and the secondhousing part (4), wherein the second acute angle (ß) differs from the first acute angle (d).

5. The magnetic field sensor as claimed in one of the precedingclaims, characterized in that the marking (l0) extends over the most part of the circumference of the device housing (l).

6. The magnetic field sensor as claimed in one of the precedingclaims, characterized in that the marking (10) contains a 2D code.

7. The magnetic field sensor as claimed in claim 6,characterized in that the magnetic field sensor has a datamemory, and in that the 2D code contains data information corresponding to data information stored in the data memory.

8. The magnetic field sensor as claimed in one of the precedingclaims, characterized in that the first housing part (2) andthe second housing part (4) each consist of a plastics material.

9. The magnetic field sensor as claimed in one of the precedingclaims, characterized in that the jointed connection (6) is a pressure-welding connection.

10. A method for producing a magnetic field sensor, inparticular a magnetic field sensor as claimed in one of thepreceding claims, wherein a first housing part (2) and a secondhousing part (4) of a device housing (l) of the magnetic fieldsensor are joined and are connected by means of a nonreleasablejointed connection (6), characterized in that a housing outerside (8) of the device housing (l) is provided with a graphicmarking (10) in such a way that the first housing part (2) isprovided with a first marking part (20) of the marking (l0),and the second housing part (4) is provided with a secondmarking part (22) of the marking (l0), to be precise in such a way that the first marking part (20) and the second marking part (22) graphica11y match up and in such a way that the two marking parts (20, 22) transition seam1ess1y into one another.

11. The method as c1aimed in c1aim 10, characterized in thatthe housing outer side (8) is provided with the marking (10) by means of a 1aser method.

12. The method as c1aimed in c1aim 10 or 11, characterized inthat the housing outer side (8) is provided with the marking(10) over a portion of a circumference of the device housing (1).

13. The method as c1aimed in one of c1aims 10 to 12,characterized in that first the housing outer side (8) isprovided with a first marking segment (16) of the marking (10)that extends over a first portion of the circumference of thedevice housing (10), in that then the magnetic fie1d sensor isrotated through a specified ang1e (V2) about a 1ongitudina1axis (L) of the device housing (1), and in that then thehousing' outer side (8) is provided. with. a second. markingsegment (14) of the marking (10) that extends over a second portion of the circumference of the device housing (1).

14. The method as c1aimed in c1aim 13, characterized in thatthe magnetic fie1d sensor is rotated through a second specifiedangle (V3) about the 1ongitudina1 axis (L) of the devicehousing (1), and in that then the housing outer side (8) isprovided with a third marking segment (12) of the marking (10)that extends over a third portion of the circumference of the device housing (1).