Atr sensor base assembly having a magnetically fixed, porous separating component

Abstract

The invention relates to an ATR sensor base assembly (10) comprising: - a measuring range assembly (14) comprising + an ATR element (26) and + a framing component (18) which frames the ATR element (26), wherein the ATR element (26) has a measurement interface (26a) which faces the external surroundings (U) of the measuring range assembly (14) and is accommodated on the framing component (18) in such a way that the measurement interface (26a) is exposed on the measuring range assembly (14) towards the external surroundings (U) of the measuring range assembly (14), - a porous separating component (22) which is designed to be detachably arranged on the measuring range assembly (14) so as to at least partially cover the measurement interface (26a), and - a holding component (20) which is designed to be detachably arranged on the measuring range assembly (14) so as to at least partially cover the porous separating component (22) and, when arranged, to exert a loading force (B) onto the separating component (22), which loading force acts in the direction of the measuring range assembly (14). According to the invention, the ATR sensor base assembly (10) comprises a magnet assembly (31) in such a way that the loading force (B) exerted onto the separating component (22) between the holding component (20) and the measuring range assembly (14) has at least one magnetic force component.

Description

[0001] ATR sensor base assembly with magnetically fixed porous sheath component

[0002] Description

[0003] The present invention relates to an ATR sensor base assembly for forming an ATR sensor or for use in an ATR sensor that uses an evanescent field to detect information. The abbreviation ATR, known in this context, stands for "Attenuated Total Reflection." The ATR sensor base assembly comprises a measuring range assembly with an ATR element and a mounting component that holds the ATR element.

[0004] The ATR element has a measuring interface facing the outside environment of the measuring range assembly. During normal measuring operation, total internal reflection occurs at the measuring interface of the ATR element when electromagnetic radiation, typically infrared radiation, is transmitted through the ATR element, creating the evanescent field used to obtain information in the outside environment of the measuring interface. The ATR element is therefore mounted on the mounting component in such a way that the measuring interface on the measuring range assembly is exposed to the outside environment of the measuring range assembly, allowing a substance to be detected by a sensor to be exposed to the evanescent field.

[0005] The ATR sensor base assembly further comprises a porous sheath component which is designed to be detachably arranged on the measuring range assembly and at least partially cover the measuring interface.

[0006] The ATR sensor base assembly further comprises a retaining component designed for detachable mounting on the measuring range assembly, at least partially covering the porous sheath component, and, in the mounted state, for exerting a loading force on the sheath component, acting toward the measuring range assembly. An ATR sensor with an ATR sensor base assembly designed as described above is known from US Pat. No. 11,371,882 B2. The known ATR sensor is used to examine blood samples, wherein the porous sheath component in US 11,371,882 B2 serves a purpose that differs from the purpose of the porous sheath component of the present invention: the porous sheath component of US 11,371,882 B2 serves to ensure, due to the capillary forces acting in the pores of the sheath component, that liquid blood components for a measurement are located in the region of the evanescent field forming on the outside of the measuring interface.

[0007] Another ATR sensor is known from US 2021 / 165123 A1. The physical properties and operating principles used by the attenuated total reflection measurement principle to gain knowledge, as well as their metrological application, are very well explained in DE 103 16 514 A1, the description of which is referred to here to explain the measurement principle.

[0008] Further ATR sensors are known, for example, from US 7,593,107 B2 and from EP 3 026426 A1.

[0009] For hygienic reasons, the porous sheath component is typically used for only a single measurement and then replaced. The measuring range assembly with the relatively expensive ATR element, on the other hand, is usually reused after cleaning.

[0010] It is an object of the present invention to further develop the ATR sensor base arrangement mentioned at the outset in such a way that the porous sheath component can be easily and safely arranged on the measuring range assembly and can be replaced by another sheath component.

[0011] The present invention solves this problem by means of an ATR sensor base arrangement as mentioned above, which additionally comprises a magnet arrangement such that a loading force exerted on the separating component between the holding component and the measuring range assembly has at least one magnetic force component.

[0012] The terminology used in this application is as follows: the measuring range assembly directly provides the measuring interface, on the outside of which the evanescent field required for information acquisition is generated during measurement operation. The measuring range assembly is part of the ATR sensor base assembly, which adds further elements to the measuring range assembly but does not necessarily include a source of electromagnetic radiation, a receiver for the radiation emitted by the source, and any control unit required for an ATR sensor. The ATR sensor base assembly can be supplemented to form an ATR sensor by adding an electromagnetic radiation source, in particular an infrared source, and a radiation receiver. The ATR sensor can have its own control unit in its sensor housing or can be controlled by an external control unit.

[0013] The ATR sensor base assembly of the present application is described in the ready-to-measure state unless explicitly stated otherwise or unless the content necessarily indicates otherwise.

[0014] It cannot be ruled out that, depending on the orientation of the ATR sensor base assembly during measurement operation, gravity—in this case, the weight of the holding component—also contributes to the loading force. However, the magnetic force component is preferably the predominant force component, which allows the porous separating component to be clamped between the holding component and the measuring range assembly.

[0015] The magnetic force component that holds the holding component and the porous separating component arranged between the holding component and the measuring range assembly to the measuring range assembly is preferably so large in magnitude, through the selection of the magnet arrangement used for this purpose, that the holding component is held to the measuring range assembly regardless of the orientation of the ATR sensor base assembly in the Earth's gravitational field. In principle, within the scope of the invention, it is conceivable that further loading means can be provided to generate a mechanical force component in addition to the magnetic force component in order to load the holding component towards the measuring range assembly. Further loading means can comprise at least one spring clip and / or at least one screw and / or locking formations on the holding component and the measuring range assembly to form an surmountable locking connection.

[0016] However, since it is preferably intended, on the one hand, to arrange an ATR sensor equipped with the ATR sensor base arrangement with an outer surface that is as smooth as possible in a sleeve that fits closely to the outer surface of the sensor as a holder, in order to be able to change the porous sheath component on the ATR sensor base arrangement with as few manual steps as possible and particularly preferably without tool intervention and engagement formations provided for tool intervention on the ATR sensor base arrangement, the magnet arrangement is preferably the only holding means on the ATR sensor base arrangement, which provides a loading force of the holding component in the direction of the measuring range assembly that is independent of the orientation of the ATR sensor base arrangement in the gravitational field.

[0017] As already stated at the beginning, the porous sheathing component of the present invention serves a different purpose than in the cited prior art. While it should not be ruled out that the ATR sensor base assembly discussed here could also be used for the metrological detection of blood samples, and in particular their liquid components, the ATR sensor base assembly discussed here is preferably intended for use in bioreactors or comparable technical devices.Unlike in US 11,371,882 B2, the porous separating component of the present invention is not placed on the measuring interface of the ATR element already provided with a sample, but is arranged in a clean state on the measuring area assembly and only comes into contact with the substance to be detected by the evanescent field on the outside of the measuring interface after the ATR sensor equipped with the ATR sensor base arrangement has been arranged in a measuring space, preferably a reaction space of a biological or chemical reactor.

[0018] The aforementioned reaction chambers typically contain fluids, particularly liquids, that contain a certain amount of suspended matter. These suspended matter may be starting products or reaction residues from biological and / or chemical reactions taking place in the fluid. These suspended matter can adversely affect the measurement if they enter the evanescent field of the ATR sensor base assembly. The porosity of the porous separating component in the present invention is therefore selected such that interfering components contained in the substance to be detected, which could adversely affect a measurement, are kept away from the measuring interface, while components that are actually to be detected are allowed to pass through to the measuring interface.

[0019] A preferred embodiment of the porous separating component is a porous plastic membrane, for example, made of polyethersulfone (hereinafter referred to as "PES"). For typical applications in the field of bio-fermentation or in biological reactors, the plastic membrane can have a thickness in the range of 0.05 mm to 0.2 mm and can have an average pore size of 0.1 μm to 0.5 μm, preferably 0.15 μm to 0.25 μm, particularly preferably 0.2 μm. However, these are only exemplary values ​​for a preferred application.

[0020] In principle, the magnet arrangement can comprise or be an electromagnet arrangement that can be supplied via a power supply of an electromagnetic radiation source, in particular an infrared radiation source, present in an ATR sensor equipped with the ATR sensor base arrangement discussed here. The electromagnet arrangement can also be controlled via a control device present in the ATR sensor, whereby control is also understood to include switching on and off.

[0021] However, the ATR sensor base assembly should be provided with the smallest possible installation volume. The active measuring area of ​​an ATR sensor, comprising the ATR sensor base assembly, is preferably cylindrical with a diameter of no more than 12 mm. Furthermore, electromagnets form heat sources, which can have undesirable side effects in an ATR sensor. Therefore, the use of at least one electromagnet as the magnet assembly or a part thereof is conceivable in principle within the scope of the present invention, but not preferred.

[0022] For reasons of reliable function with low installation space requirements and advantageous independence from energy sources, a preferred development of the present invention provides that at least one component of the socket component and the holding component has or is a permanent magnet arrangement.

[0023] To achieve the highest possible load force exerted by the holding component on the measuring range assembly, at least one permanent magnet can be arranged both in the holding component and on the measuring range assembly side, for example in the socket component and / or in a sensor housing accommodating the measuring range assembly. The permanent magnets of the holding component and on the measuring range assembly side overlap in the ready-to-measure state when viewed orthogonally to the measuring interface when the porous separating component arranged above the measuring interface is viewed. This ensures that each of the overlapping permanent magnets is located in the magnetic field of the other permanent magnet. Unlike poles of the overlapping permanent magnets in the holding component on the one hand and on the measuring range assembly side on the other hand point towards each other to increase the load force.

[0024] Permanent magnets, especially those made of rare earths, are expensive. Therefore, it may be sufficient for one component of the socket component and the holding component to have or be a permanent magnet arrangement, and for the other component of the socket component and the holding component to be formed at least partially from a soft magnetic material. The soft magnetic material is preferably ferromagnetic, but not permanently magnetized, but can also be paramagnetic. However, ferromagnetic soft magnetic materials typically achieve higher load forces in the same magnetic field as a permanent magnet.

[0025] In principle, it is conceivable that one permanent magnet or two or more permanent magnets are inserted into the holding component and / or the socket component and / or the sensor housing. Then, the component carrying the at least one permanent magnet can have a locally strong magnetic field at the location of the at least one permanent magnet.

[0026] Alternatively, according to one embodiment of the present invention, it is conceivable that a component comprising the socket component and the holding component is formed, at least in sections, from a material filled with magnetized or magnetizable particles. This is preferably the holding component, which can be designed as a disposable component since, for example, unlike the socket component, it is not permanently connected to the relatively expensive ATR element made of a waveguide material. Particularly preferably, the entire holding component, or at least 80 percent by weight thereof, can be formed from the material filled with magnetized or magnetizable particles.

[0027] The particle-filled material can advantageously be manufactured by primary molding, for example, by injection molding, and can thus be produced in large quantities with sufficient shape and dimensional accuracy. The particles are preferably mixed unmagnetized into the plastic compound, then the holding component is molded, and then, once the particles are fixed in the cured holding component, magnetized. This ensures consistent polarization of the holding component or its at least one magnetizable section across a large number of holding components. Thus, a holding component made of a particle-filled material, preferably a thermoplastic material, can interact with permanent magnets incorporated in the mounting component or sensor housing to increase the load force due to its repeatable polarization.

[0028] In principle, the socket component can also be partially or completely formed from a material filled with magnetized or magnetizable particles. The statements regarding the holding component apply mutatis mutandis to the socket component.

[0029] The socket component can, in principle, be a separate component that is accommodated in a sensor housing of the ATR sensor base assembly. Preferably, the socket component is at least a portion of a sensor housing of the ATR sensor base assembly. If the sensor housing is formed from a soft magnetic metal, at least in the portion thereof forming the socket component, the ATR sensor base assembly can be manufactured with an advantageously small number of components.

[0030] The socket component and the holding component can be formed in one piece or in multiple pieces. Preferably, the holding component is a single-piece, preformed component, optionally with separate permanent magnets mounted thereon.

[0031] The loading force acting in the direction from the holding component to the measuring range assembly, which is a magnetic attraction force, is preferably sufficient to hold the porous partition component to the measuring range assembly and, if necessary, also provide a certain degree of tightness in the gap between the holding component and the measuring range assembly. Under the effect of the loading force, the holding component can compress the pores of the porous partition component located between it and the measuring range assembly. Sections of the porous partition component that are not contacted by the material of the holding component can remain uncompressed and fulfill their function as a partition formation.

[0032] In order to shield the separating component from the ingress of substance from the measuring chamber into the separating component through the edge of the separating component pointing outwards between the holding component and the measuring range assembly, at least one component of the holding component and the measuring range assembly can have a sealing lip which at least partially covers the edge of the separating component. The at least one sealing lip on the holding component and the measuring range assembly can be formed so as to run all the way around the separating component, preferably in a closed manner. It can project radially outwards from the component carrying it in the thickness direction and optionally also with respect to the circumferential direction. The sealing lip can be formed integrally with the holding component and / or with the measuring range assembly, in particular with its mounting component or the sensor housing.Alternatively or additionally, a sealing component formed separately from the holding component and / or the measuring range assembly, preferably with a sealing lip designed according to the above description, can be arranged on the holding component and / or on the measuring range assembly.

[0033] However, the magnetically induced loading force may not be sufficient to secure the holding component against displacement relative to the measuring range assembly parallel to the measuring interface without further measures. In reaction chambers of biological and chemical reactors, flows prevail which exert forces in changing, unpredictable directions on an ATR sensor arranged therein. To prevent the holding component from shifting relative to the measuring range assembly during a measurement of the ATR sensor, a preferred development of the present invention provides that, when the ATR sensor base assembly is in the ready-to-measure state, the holding component is in positive engagement with the socket component and / or the sensor housing in such a way that the positive engagement limits or prevents relative movement between the holding component and the socket component parallel to the measuring interface.

[0034] Likewise, the positive engagement preferably does not prevent the holding component from lifting off the measuring range assembly in a direction transverse, in particular orthogonal, to the measuring interface. As already indicated above, the holding component, as part of a substantially rotationally symmetrical, preferably conical or particularly preferably cylindrical, ATR sensor, has a partially rotationally symmetrical, preferably partially conical or particularly preferably partially cylindrical shape on its outer surface facing away from the measuring range assembly. A loading surface of the holding component facing the measuring interface, with which the latter exerts the loading force on the porous separating component, is preferably at least largely, particularly preferably completely, flat. Likewise, the measuring interface is preferably flat.The support surface of the measuring range assembly surrounding the measuring interface, which is opposite the load surface of the holding component, is preferably largely or completely flat.

[0035] The outer surface of the holding component and the outer surface of the section of the sensor housing supporting the measuring range assembly can, in the ready-to-measure state, complement each other to form an overall outer surface of the ATR sensor with, apart from joining gaps, measuring windows, and the like, a substantially rotationally symmetrical, preferably conical or particularly preferably cylindrical, shape. Preferably, the outer dimensions of the ATR sensor, from its longitudinal end leading in an insertion direction into a holder, in particular the aforementioned sleeve as the holder, to beyond the measuring range assembly, do not exceed a diameter of 12 mm. This ensures that the ATR sensor can be inserted into a precisely fitting holder that encompasses the sensor in the held state by simply inserting it sufficiently deep so that its measuring range is located as intended in a measuring space.

[0036] The angular range that the outer surface of the retaining component occupies around the cone or cylinder axis on the entire outer surface is preferably less than 180°, particularly preferably less than 140°. With this preferred configuration of the entire outer surface of the ATR sensor, without the formation of the aforementioned positive engagement, the flows prevailing in the measuring chamber may possibly cause a displacement of the retaining component relative to the measuring range assembly parallel to the measuring interface, but not a force sufficient to lift the retaining component off the measuring range assembly.

[0037] The positive engagement can be achieved by a component comprising the holding component on the one hand and the socket component and / or the sensor housing on the other hand having a projection which, when ready for measurement, engages in a complementary recess on the other component. The recess runs at least along a lifting path along which the holding component was arranged on the measuring range assembly in a measuring-ready state and can be lifted off again. If the projection and the recess are arranged not on the load surface of the holding component or on the support surface of the measuring range assembly, but on flank surfaces running transversely thereto, the projection and the recess can protrude or be recessed parallel to the measuring interface.

[0038] In a particularly advantageous embodiment of the present invention, which is easy to manufacture and intuitive to handle, the socket component and / or the sensor housing can have a recess into which the holding component is inserted when the ATR sensor base assembly is ready for measurement. The holding component then essentially forms a positive-locking formation, which can be brought into positive engagement with the socket component or sensor housing by being inserted into the recess on the socket component and / or the sensor housing. The recess is preferably designed to complement the edge portion of the holding component inserted into it, so that when the ATR sensor base assembly is ready for measurement, a gap with a preferably constant gap width extends over at least 75% of the circumferential length between the edge of the recess and the edge portion of the holding component.Particularly preferably, the recess and the edge portion of the retaining component inserted into it are designed to complement each other according to the lock-and-key principle. Likewise, particularly preferably, one edge of the recess extends completely around the retaining component inserted into the recess. If the gap width is then constant along the closed circumference, the positive fit can contribute to shielding the separating component from a substance by its outer edge, for example, in the manner of a labyrinth, if the gap width is selected accordingly. Preferably, the edge of the recess projects beyond the edge of the separating component when ready for measurement.

[0039] In principle, in preparation for a measurement process, it is conceivable to place the porous sheath component as a separate component on the measuring interface of the ATR element and to secure it by subsequently arranging the holding component on the porous sheath component. A simpler and faster preparation of the ATR sensor base assembly for a measurement process can advantageously be achieved by connecting the porous sheath component and the holding component to one another as a prefabricated assembly. If the holding component is produced by injection molding, it is conceivable to mold the holding component directly onto the porous sheath component. Alternatively, the porous sheath component can be glued to the holding component, for example, with silicone adhesive.

[0040] When the ATR sensor base assembly is ready for measurement, the separating component is positioned between the measuring range assembly and the holding component in such a way that a section of the separating component located above the measuring interface is accessible from the outside environment. This allows the measuring interface, and thus the evanescent field formed at it during measurement operation, to be reached by a substance that is to be sensed by an ATR sensor equipped with the ATR sensor base assembly.

[0041] To ensure accessibility of the porous separating component during a measurement process, the holding component can form a frame with an opening extending through the holding component, at least when the ATR sensor base assembly is in the measurement-ready state. The opening of the holding component, which forms a measurement window of the same, is then located in the region of the measurement interface, so that not only the porous separating component is accessible from fluid in the external environment of the ATR sensor base assembly, but also the measurement interface, where the relevant evanescent field is formed.

[0042] To provide a sufficient loading force, the holding component can project beyond the measuring interface in at least two opposite directions, with at least one magnet arrangement being provided in each of the regions of the holding component projecting beyond the measuring interface. The two projecting regions are preferably located on either side of the aforementioned opening. The present invention also relates to an ATR sensor with an ATR sensor base arrangement as explained and further developed above, and with an electromagnetic radiation source and a receiver sensitive to the electromagnetic radiation after it has passed through the ATR element.

[0043] With the ATR sensor base assembly of the present invention, an advantageously fast and safe method for preparing an ATR sensor for use can be carried out, which comprises the following steps:

[0044] Placing a porous separating component unwetted by a substance to be detected onto a measuring interface of an ATR element, and

[0045] Securing the porous sheath component at the measuring interface by placing a holding component on a measuring range assembly comprising the ATR element and a socket component enclosing the ATR element, wherein the holding component is held to the measuring range assembly with the participation of a magnetic loading force.

[0046] In an advantageous further development, the method may comprise, after the securing step, a step of arranging the measuring interface with the porous separating component in a measuring space.

[0047] The present invention is explained in more detail below with reference to the accompanying drawings. It shows:

[0048] Fig. 1 is a schematic representation of a first embodiment of an ATR sensor base arrangement according to the invention in a state ready for measurement,

[0049] Fig. 2 shows the first embodiment of Figure 1 in a schematic exploded view,

[0050] Fig. 3 is a schematic representation of a second embodiment of an ATR sensor base arrangement according to the invention in a state ready for measurement, and Fig. 4 is a schematic exploded view of the second embodiment of Figure 3.

[0051] Figure 1 shows a first embodiment of an ATR sensor base assembly according to the invention in a schematic perspective view and is designated by reference numeral 10. Figure 2 shows the same embodiment in a schematic exploded view. The following description of the first embodiment refers expressly to both Figures 1 and 2. In all figures, "U" denotes an external environment surrounding the respective ATR sensor base assembly.

[0052] The ATR sensor base assembly 10 comprises a cylindrical sensor housing 12 extending along a virtual cylinder axis Z, into which a measuring range assembly 14 (see Figure 2) is inserted. The sensor housing 12 has a flattened portion 16 in the region where the measuring range assembly 14 is received.

[0053] In Figure 2, the observer of the measuring range assembly 14 looks at a socket component 18 belonging to the measuring range assembly 14 with a substantially flat support surface 18a, on which a holding component 20 rests in the ready-to-measure state shown in Figure 1 with the interposition of a porous separating component 22 in the form of a 0.1 mm thin membrane made of PES with a nominal pore size of 0.2 pm.

[0054] In the first embodiment shown in Figures 1 and 2, the porous sheathing component 22 is firmly connected to the holding component 22, for example by gluing.

[0055] The mounting component 18, formed in the first embodiment from ferromagnetic but unmagnetized metal, in particular steel, has a central window 24 through which the observer in Figure 2 looks onto the outer side 26a1 of the measuring interface 26a of an ATR element 26. The ATR element 26 is formed from waveguide material that transmits electromagnetic radiation in the infrared range. On the inner side of the measuring interface 26a, opposite the outer side 26a1 of the measuring interface 26a, total reflections of the transmitted electromagnetic radiation occur during a measuring process and thus during a transmission of the electromagnetic radiation, whereby an evanescent field is formed on the outer side 26a1, in its immediate vicinity, which field is influenced by a substance to be detected by the ATR measurement.The influence of the substance being detected on the evanescent field formed by the transmitted electromagnetic radiation is reflected in the transmitted electromagnetic radiation itself and can be detected and evaluated by comparing the transmitted radiation with a reference radiation, such as the originally emitted radiation. The functioning of ATR sensors is well known.

[0056] In the first embodiment shown, the socket component 18 does not have to be made entirely of soft magnetic steel. However, it is helpful if at least the support surface 18a is made of soft magnetic steel, so that the holding component 20 and a magnetic field emanating from it are arranged with the smallest possible gap distance from the support surface 18a when the ATR sensor base assembly 10 is ready for measurement. As a result, for a given magnetic field emanating from the holding component 20, the greatest possible attractive force can be exerted by the holding component 20 towards the measuring range assembly 14. This attractive force causes a loading force B (see Figure 1), which the holding component 20 exerts on the porous separating component 22 arranged between it and the support surface 18a of the socket component 18. The loading force B is represented in Figure 1 by four arrows orthogonal to the support surface 18a.

[0057] The underside of the holding component 20, which is not shown in the figures, is designed as the loading surface mentioned in the introduction to the description, just as the porous separating component 22 which is firmly connected to the holding component 20 is flat.

[0058] To ensure a clear orientation of the holding component 20 in the ready-to-measure state shown in Figure 1, the socket component 18 is inserted into a recess 28 formed in the sensor housing 12 or in its flattened portion 16. This recess or depression 28 has a border 28a which has slightly larger clear widths than the length or width of the holding component 20. Thus, the holding component 20 can be inserted into the recess 28 without much effort, without having excessive play in directions parallel to the support surface 18a.

[0059] The edge 28a of the recess 28 has a shape which is complementary to the lateral circumferential edge 20a of the holding component 20, so that when the holding component 20 is inserted into the recess 28, a joint formed between the edge 20a of the holding component 20 and the edge 28a of the recess 28 in the ready-to-measure state runs around the holding component 20 with an approximately constant joint width.

[0060] The depth of the recess 28, to be measured orthogonally to the support surface 18a, is smaller than the thickness D of the holding component 20, preferably even smaller than half the thickness D. This allows the holding component 20 to be gripped laterally with a fingernail or a blade when ready for measurement operation, in order to facilitate or enable the holding component 20 to be lifted off the support surface 18a. When ready for measurement operation, the holding component 20 can be lifted off in the lifting direction A against the loading force B magnetically loading the holding component 20 towards the measuring range assembly 14, provided that the magnetic attraction force caused by the holding component 20 in interaction with the socket component 18 is overcome. The lifting direction A is opposite to the direction of action of the loading force B.

[0061] To facilitate mechanical attack, an engagement groove 30 extending in the longitudinal direction and orthogonal to the direction of the thickness D can be formed in the longitudinal section of the edge 20a.

[0062] In the first embodiment, the holding component 20 is manufactured entirely from a thermoplastic filled with ferromagnetic particles 31 by injection molding. The holding component 20 has a practical plate shape with a substantially constant thickness D across the entire holding component 20. After the primary forming of the holding component 20, the ferromagnetic particles 31 were permanently magnetized in its cured state by magnetization in a strong magnetic field.

[0063] The holding component 20 has a central opening 32 as a measuring window, which completely penetrates the holding component 20 in the thickness direction, so that the observer in Figures 1 and 2 looks through the opening 32 of the holding component 20 directly onto the porous sheathing component 22 spanning the opening 22. The porous sheathing component 22 preferably covers the entire underside of the holding component 20, so that no step is formed on the underside of the holding component 20.

[0064] In addition or alternatively to mechanically levering the holding component 20 out of the recess 28 in the lifting direction A and thus away from the measuring range assembly 14, the holding component 20 can be removed from the position shown in Figure 1 by a release magnet 34. The release magnet 34 has such a strong magnetic field that the holding component 20 adheres magnetically to the release magnet 34 rather than to the support surface 18a of the socket component 18, which is made of soft magnetic material.

[0065] Alternatively, the socket component 18 can be formed integrally with the sensor housing 12 if the latter is made of ferromagnetic material. Instead of a recess 28, which is difficult to produce in the case of a one-piece design, the entire surface of the flattened portion 16 facing in the lifting direction A can be designed as a preferably flat support surface 18a for supporting the porous separating component 22 and the holding component 20. Positional securing of the holding component 20 can then be achieved by a few projections soldered, glued, or otherwise attached to the surface of the flattened portion 16 facing in the lifting direction A.

[0066] An ATR sensor prepared for use as shown in Figure 1, including the ATR sensor base assembly 10, can be arranged in a measuring chamber with a virgin porous separating component 22 via a holder not shown in the figures, and can be brought into contact with a suspension to be measured. The porous separating component 22 keeps suspended matter in a carrier fluid away from the immediate outer side 26a1 of the measuring interface 26a and thus from the evanescent field, ensuring that only the carrier fluid of the suspension actually to be measured passes through the pores in the separating component 22 into the evanescent field and influences the measurement in the desired manner.

[0067] Figures 3 and 4 illustrate a second embodiment of an ATR sensor base assembly 110 according to the invention. The ATR sensor base assembly 110 of the second embodiment will be described in detail below only to the extent that it differs from the first embodiment, the description of which is otherwise also applicable to explaining the second embodiment.

[0068] Identical and functionally equivalent components and component sections as in the first embodiment are provided with the same reference numerals in the second embodiment, but increased by the number 100.

[0069] Again, Figure 3 shows a ready-to-measure state and Figure 4 shows a schematic exploded view of the embodiment of Figure 3.

[0070] As can be seen primarily in Figure 4, the porous sheathing component 122 is designed and provided as a separate component from the holding component 120, which is placed onto the measuring interface 126a of the ATR element 126 in a separate application process. The holding component 120 is then placed onto the porous sheathing component 122 already arranged on the measuring range assembly 114. However, it should not be fundamentally ruled out that the porous sheathing component 122 is also permanently connected to the underside of the holding component 120 in the second embodiment.

[0071] A further difference between the first and the second embodiment is that the holding component 120 is not formed from plastic filled with magnetizable or magnetized particles, but from any material, for example from thermoplastic and thus injection-moldable plastic.

[0072] In order to provide the magnetic loading force which, during measuring operation, loads the holding component 120 in the direction of the measuring range assembly 114, a permanent magnet 136 is installed in the holding component 120 in the longitudinal direction on both sides of the opening 132, for example by being overmolded or glued into a recess of the holding component 122.

[0073] Although in the second embodiment, the socket component 118 could again be formed from a soft magnetic material, at least on its side forming the support surface 118a, as an alternative possibility, Figures 3 and 4 show that magnetic active components 138 can be inserted into the socket component 118, which, in the ready-to-measure state shown in Figure 3, are aligned with the permanent magnets 136 when viewed opposite the lifting direction A, or are at least arranged so as to overlap them. The magnetic active components 138 are arranged on either side of the window 124 in the socket component 118. In this case, the socket component 118 can also be formed from plastic.

[0074] The magnetic active components 138 can also be permanent magnets to achieve a particularly high magnetic attraction force, wherein these are then arranged such that, in the ready-to-measure state, unlike poles of the permanent magnets 136 and the active components 138 are opposite one another.

[0075] Alternatively, the magnetic active components 138 can be soft magnetic active components which, in cooperation with the magnetic fields of the permanent magnets 136 in the holding component 122, cause a magnetic attraction force which loads the holding component 122 towards the measuring range assembly 114.

[0076] Although the socket component 118 could again be formed integrally with the sensor housing 112 in the flattened portion 116, it is inserted as a separate component into a recess 128 in the flattened portion 116 of the sensor housing 112. However, in the second embodiment, the depth of the recess 128 corresponds to the thickness of the socket component 118, so that the flat support surface 118a of the socket component 118 in the illustrated second embodiment is arranged flush with the flat surrounding surface of the flattened portion 116.

[0077] The holding component 120 of the second embodiment is longer and wider than the socket component 118 of the second embodiment. It projects beyond the socket component 118, primarily in the longitudinal direction. The same applies to the porous sheath component 122, which also projects beyond the socket component 118.

[0078] As a means of fixing the position of the holding component 120 and the porous separating component 122, a recess 140a and 140b is formed on the end face in the flanks that delimit the flattening 116 axially with respect to the cylinder axis Z.

[0079] The recesses 140a and 140b are mirror-symmetrical with respect to a mirror symmetry axis orthogonal to the cylinder axis Z, so that the following description of the recess 140a is sufficient.

[0080] The recess 140a extends parallel to the lifting direction A, so that, above all, the rigid holding component 120 can be placed on the measuring range assembly 114 opposite to the lifting direction A.

[0081] The recess 140a is formed in the lifting direction A with two different shapes, namely a wider partial recess 140a1, which is located closer to the measuring interface 126a and which is associated with a projection 122a of the porous separating component 122 by complementary formation, and a narrower partial recess 140a2, which is located further away from the measuring interface 126a in the lifting direction A and which is associated with a projection 120b of the holding component 120 by complementary formation.

[0082] The porous separating component 122, which is designed as a thin and therefore flexible membrane, can be placed flat on the measuring range assembly 114 and thus on the measuring interface 126a with little deformation, wherein its projection 122a is received in the wider partial recess 140a1.

[0083] The projection 120b, which projects in the axial direction with respect to the cylinder axis Z and runs parallel to the lifting direction A, can be moved in the narrower partial recess 140a2 acting as a groove only in and against the lifting direction A, whereby an undesired displacement of the holding component 120 orthogonal to the lifting direction is reliably prevented by form closure.

[0084] As can also be seen in Figures 3 and 4, the sensor housing 112 is formed in several parts in the axial direction with respect to the cylinder axis Z.

[0085] In the embodiments shown, in order to avoid misalignments, the holding components 20 and 120 and the porous separating components 22 and 122 are also mirror-symmetrical with respect to a first mirror symmetry plane orthogonal to the cylinder axis Z and mirror-symmetrical with respect to a second mirror symmetry plane orthogonal to the first mirror symmetry plane, containing the cylinder axis Z and orthogonal to the support surface 118a.

[0086] The first and second embodiments differ primarily in the different provision of a magnetic force emanating from the holding component. The shape and / or dimensions of the holding component and the measuring range assembly interacting with the holding component of one embodiment can be applied to the other embodiment, and vice versa. In particular, the holding component of the first embodiment can also be designed with a shape that complements the shape of the sensor housing in the ready-to-measure state, with the exception of unavoidable gaps, to form a rotating body.

Claims

Claims 1. ATR sensor base assembly (10; 110) comprising: a measuring range assembly (14; 114) with + an ATR element (26; 126) and + a holder component (18; 126) holding the ATR element (26; 126) 118), wherein the ATR element (26; 126) has a measuring interface (26a; 126a) facing the external environment (U) of the measuring range assembly (14; 114) and is received on the mounting component (18; 118) in such a way that the measuring interface (26a; 126a) on the measuring range assembly (14; 114) is exposed to the external environment (U) of the measuring range assembly (14; 114), a porous separating component (22; 122) which is designed for a detachable arrangement on the measuring range assembly (14; 114) at least partially covering the measuring interface (26a; 126a), and a holding component (20; 120) which is designed for a detachable arrangement, the porous separating component (22; 122) at least partially covering arrangement on the measuring range assembly (14; 114) and in the arranged state is designed to exert a loading force (B) acting towards the measuring range assembly (14; 114) on the sheath component (22; 122), characterized in that the ATR sensor base arrangement (10; 110) has a magnet arrangement (31 ;136) such that the loading force (B) exerted on the separating component (22; 122) between the holding component (20; 120) and the measuring range assembly (14; 114) has at least one magnetic force component.; 2. ATR sensor base arrangement (10; 110) according to claim 1, characterized in that at least one component of the socket component (18; 118) and the holding component (20; 120) has or is a permanent magnet arrangement (31; 136).

3. ATR sensor base arrangement (10; 110) according to claim 1 or 2, characterized in that one component of the socket component (18; 118) and the holding component (20; 120) has or is a permanent magnet arrangement (31; 136) and the other component of the socket component (18; 118) and the holding component (20; 120) is formed at least in sections from soft magnetic material.

4. ATR sensor base arrangement (10) according to claim 2 or 3, characterized in that a component of the socket component (18) and the holding component (20) is formed at least in sections from a material filled with magnetized or magnetizable particles (31).

5. ATR sensor base assembly (10; 110) according to one of the preceding claims, characterized in that the socket component (18; 118) is at least a portion of a sensor housing (12; 112) of the ATR sensor base assembly (10; 110) or is received on a sensor housing (12; 112) of the ATR sensor base assembly (10; 110).

6. ATR sensor base arrangement (10; 110) according to claim 5, characterized in that the holding component (20; 120) is in positive engagement with the socket component (18; 118) and / or the sensor housing (12; 112) in the measuring-operational state of the ATR sensor base arrangement (10; 110) in such a way that the positive engagement limits or prevents a relative movement between the holding component (20; 120) and the socket component (18; 118) parallel to the measuring interface (26a; 126a).

7. ATR sensor base arrangement (10) according to claim 6, characterized in that the socket component (18) and / or the sensor housing (12) has a recess (28) into which the holding component (20) is inserted in the measuring-operational state of the ATR sensor base arrangement (10).

8. ATR sensor base assembly (10) according to one of the preceding claims, characterized in that the sheath component (22) and the holding component (20) are connected to one another as a prefabricated assembly.

9. ATR sensor base arrangement (10; 110) according to one of the preceding claims, characterized in that the separating component (22; 122) is arranged between the measuring range assembly (14; 114) and the holding component (20; 120) in the measuring-operational state of the ATR sensor base arrangement (10; 110) in such a way that a section of the separating component (22; 122) arranged above the measuring interface (26a; 126a) is accessible from the external environment (U).

10. ATR sensor base assembly (10; 110) according to one of the preceding claims, characterized in that the holding component (20; 120), at least in the measurement-ready state of the ATR sensor base assembly (10; 110), forms a frame with an opening (32; 132) passing through the holding component (20; 120), which opening is covered by the porous separating component (22; 122).

11. ATR sensor base arrangement (10; 110) according to one of the preceding claims, characterized in that the holding component (20; 120) projects beyond the measuring interface (26a; 126a) in at least two opposite directions, wherein at least one magnet arrangement (31; 136) is provided in each of the regions of the holding component (20; 120) projecting beyond the measuring interface (26a; 126a).

12. ATR sensor comprising an ATR sensor base assembly (10; 110) according to any one of the preceding claims, comprising an electromagnetic radiation source and a receiver sensitive to the electromagnetic radiation after passage through the ATR element (26; 126).

13. A method for preparing an ATR sensor for measurement operation on an ATR sensor base assembly (10; 110) according to any one of the preceding claims, the method comprising the following steps: Placing a porous separating component (22; 122) unwetted by a substance to be detected onto a measuring interface (26a; 126a) of an ATR element (26; 126), and Securing the porous separating component (22; 122) at the measuring interface (26a; 126a) by placing a holding component (20; 120) onto a measuring range assembly (14; 114) comprising the ATR element (26; 126) and a holder component (18; 118) holding the ATR element (26; 126), wherein the holding component (20; 120) is held on the measuring range assembly (14; 114) with the participation of a magnetic loading force.

14. The method according to claim 13, characterized in that after the step of securing it comprises a step of arranging the measuring interface (26a; 126a) with the porous separating component (22; 122) in a measuring space.

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