Filter insert for inserting into an insert holder of a filter system

Abstract

The invention relates to a filter insert (10) for inserting into an insert holder of a filter system (100), having a polarisable filter medium (14) through which a fluid to be filtered can flow, at least one polarising electrode (16a, 16b) for polarising the filter medium (14), and at least one electrically conductive conductor track arrangement (22) that is electrically conductively connected to the polarising electrode (16a, 16b) and can be electrically contacted by a contacting element (118a, 118b) on the insert holder.

Description

[0001] Filter insert for insertion into an insert holder of a filter system

[0002] The invention relates to a filter insert for insertion into an insert receptacle of a filter system, comprising a polarizable filter medium through which a fluid to be filtered can flow, at least one polarization electrode for polarizing the filter medium and at least one electrically conductive conductor track arrangement which is electrically conductively connected to the polarization electrode and can be electrically contacted with a contacting element on the insert receptacle side.

[0003] Furthermore, the invention relates to a filter system having a filter insert with a polarizable filter medium and at least one polarization electrode and an insert receptacle which has at least one contacting element via which a conductor track arrangement of the filter insert which is electrically conductively connected to the polarization electrode of the filter insert can be electrically contacted.

[0004] Furthermore, the invention relates to a method for testing a filter system comprising a replaceable filter insert, comprising the step of: energizing a current supply path of the filter system for polarizing a polarizable filter medium of the filter insert via at least one polarization electrode of the replaceable filter insert.

[0005] For filter systems in which a filter insert to be energized must be inserted into an insert holder, it is necessary to check the correct installation of the filter insert to ensure proper energization of the filter insert. This check can be performed by evaluating the energization of the filter insert. In addition to checking the correct installation of the filter insert, it must also be ensured that the filter insert is free of damage and functioning properly. For filter inserts with a polarization function, the coupling of the polarization voltage and thus the proper polarization of the filter medium must be checked in particular. Such a check of the polarization function has not been possible to date.

[0006] The object underlying the invention is therefore to increase the operational reliability of a filter system with a filter insert to be supplied with current.

[0007] The object is achieved by a filter insert of the type mentioned at the outset, wherein the electrically conductive conductor track arrangement of the filter insert according to the invention comprises a first conductor track which is electrically conductively connected to the polarization electrode at a first contact point, and a second conductor track which is connected to the polarization electrode at a second contact point.

[0008] The dual contacting via the first and second conductors allows the current flow to be guided through the polarization electrode. This current routing ensures that current only flows when the conductor arrangement is properly connected to the polarization electrode. This ensures that the polarization voltage is coupled in and that the filter medium is properly polarized.

[0009] The polarization electrode and the first conductor track are preferably in contact with one another at the first contact point or are connected to one another at the first contact point via an electrically conductive connecting material. The polarization electrode and the second conductor track are preferably in contact with one another at the second contact point or are connected to one another at the second contact point via an electrically conductive connecting material. The filter medium is preferably made of an electrically non-conductive material. In a preferred embodiment of the filter insert according to the invention, the first contact point and the second contact point are located on the same side of the polarization electrode. The first contact point and the second contact point are preferably located on the outer side of the polarization electrode facing away from the filter medium.The first contact point and the second contact point are preferably electrically conductively connected to one another via the polarization electrode. The polarization electrode preferably has a higher electrical conductivity than the first conductor track and / or the second conductor track.

[0010] In a further preferred embodiment of the filter insert according to the invention, the distance between the first contact point and the second contact point is less than 10 cm. Preferably, the distance between the first contact point and the second contact point is less than 5 cm. The first conductor track and the second conductor track can be fixed to the polarization electrode via separate fixing elements or via a common fixing element. The separate fixing elements or the common fixing element can be a cured adhesive. If the distance between the first contact point and the second contact point is small, a continuous adhesive strip can be used, for example. Due to the small distance between the first contact point and the second contact point, the required amount of adhesive is small, thus reducing the cost of the filter insert.When using adhesive as two separate fixing elements, the adhesive can advantageously be designed as an electrically conductive adhesive, so that a conductive contact is created between the polarization electrode and the conductor tracks. When using adhesive as a common fixing element for the two contact points, the adhesive itself is preferably not electrically conductive. In this case, the electrical contact between the conductor track and the polarization layer can be established, for example, by folding the contact point or using additional electrically conductive elements.

[0011] Furthermore, a filter insert according to the invention is preferred in which the first conductor track is connected to a contact pad, via which the filter insert can be electrically contacted with the contact element on the insert receiving side. The contact pad is preferably located on an outer side of the filter insert. The contact pad preferably has a pad width that is greater than the track width of the first conductor track. The comparatively wide contact pad simplifies contacting the filter insert.

[0012] A filter insert according to the invention is also advantageous in which the conductor track arrangement is at least partially a component of a contact element serving to electrically contact the filter insert, wherein the contact element is preferably arranged at least in sections on a lateral material strip of the filter insert. The contact element can be a contact label. The lateral material strip can be a side lamination of the filter insert. The contact element can be glued to the lateral material strip.

[0013] In a further preferred embodiment of the filter insert according to the invention, the contacting element has a contacting tab which extends beyond the lateral material strip and / or along the polarization electrode. The contacting tab preferably comprises at least one contacting section of the first conductor track, which is electrically conductively connected to the polarization electrode at the first contacting point. Alternatively or additionally, the contacting tab comprises a contacting section of the second conductor track, which is connected to the polarization electrode at the second contacting point. The contacting tab thus has a contacting section of the first conductor track and a contacting section of the second conductor track. The contacting tab thus serves for double contacting, which significantly reduces the contacting effort.

[0014] Furthermore, a filter insert according to the invention is advantageous in which the contacting element has a first contacting tab extending beyond the lateral material strip and / or along the polarization electrode, which comprises at least one contacting section of the first conductor track. The contacting section of the first conductor track is electrically conductively connected to the polarization electrode at the first contacting point. The contacting element preferably comprises a second contacting tab extending beyond the lateral material strip and / or along the polarization electrode, which comprises at least one contacting section of the second conductor track. The contacting section of the second conductor track is electrically conductively connected to the polarization electrode at the second contacting point.In this case, the first contact tab and the second contact tab each serve for single contact, so that a double contact tab is not necessary.

[0015] The filter insert according to the invention is further developed by two spaced-apart polarization electrodes for polarizing the filter medium. The conductor track arrangement is preferably electrically conductively connected to the polarization electrodes and can be electrically contacted with contact elements on the insert receptacle side. The filter medium is preferably located between the polarization electrodes. The filter medium and the polarization electrodes preferably form a capacitor.

[0016] In a further preferred embodiment of the filter insert according to the invention, the electrically conductive conductor track arrangement is electrically conductively connected to a first polarization electrode at two spaced-apart contact points and is electrically conductively connected to a second polarization electrode at one contact point, in particular at only one contact point. Depending on the current supply, the ground path or the supply path runs via the first polarization electrode. The first polarization electrode is thus used as part of the current path. Depending on the current supply, only the contact of the polarization electrode in the ground path or only the contact of the polarization electrode in the supply path can be checked.

[0017] In a further preferred embodiment of the filter insert according to the invention, the electrically conductive conductor track arrangement is electrically conductively connected to a first polarization electrode at two spaced-apart contact points and electrically conductively connected to a second polarization electrode at two spaced-apart contact points. In this case, the ground path and the supply path each run via a polarization electrode. The first polarization electrode and the second polarization electrode are thus used as part of the current path. Both the contacting of the polarization electrode in the ground path and the contacting of the polarization electrode in the supply path can be checked.

[0018] The filter insert according to the invention is further advantageously developed in that the electrically conductive conductor arrangement and / or the at least one polarization electrode are components of a voltage divider or form a voltage divider. To detect whether the conductor arrangement of the voltage divider is correctly attached to the polarization electrode, the voltage divider is guided over the polarization electrode via two conductor tracks, so that the current flow is guided via the polarization electrode. The conductive polarization electrode is thus used as part of the current path. The first conductor track and / or the second conductor track can form useful resistors of the voltage divider.

[0019] In a further preferred embodiment of the filter insert according to the invention, the polarizable filter medium is designed as an electrically insulating filter layer. The at least one polarization electrode can be designed as an electrically conductive polarization layer. The polarizable filter medium designed as an insulating filter layer and the polarization electrode designed as an electrically conductive polarization layer can be connected to one another in a materially bonded and / or force-fitting and / or positively bonded manner.

[0020] In another preferred embodiment of the filter insert according to the invention, the at least one polarization electrode and the filter medium form a multilayer pleated composite. If the filter insert has two polarization electrodes, the two polarization electrodes and the filter medium form a multilayer pleated composite, wherein the polarization electrodes are designed as electrically conductive polarization layers and the polarizable filter medium is designed as an electrically insulating filter layer. The filter medium designed as a filter layer is preferably arranged between the polarization electrodes designed as polarization layers.

[0021] The object underlying the invention is further achieved by a filter system of the type mentioned above, wherein the filter insert of the filter system according to the invention is designed according to one of the embodiments described above. With regard to the advantages and modifications of the filter system according to the invention, reference is therefore first made to the advantages and modifications of the filter insert according to the invention.

[0022] In a preferred embodiment, the filter system according to the invention has a current supply path into which the conductor track arrangement of the filter insert is integrated. The filter system preferably has an electronic data processing device configured to evaluate a current flow and / or an electrical voltage at at least one test point of the current supply path to detect a faulty operating state and / or a functional impairment of the filter system. The electronic data processing device is preferably configured to monitor the presence of a current flow or a voltage change at the at least one test point of the current supply path.If no current flows at the test point after commissioning the filter system, even though the current path is energized, this indicates that the electrically conductive connection between the first conductor track and the polarization electrode and / or the electrically conductive connection between the second conductor track and the polarization electrode is interrupted. In this case, the polarization voltage is not coupled in, so proper polarization of the filter medium does not occur. The electronic data processing device can be configured to send an error message to a higher-level control system upon detection of a faulty operating state and / or a functional impairment of the filter system.

[0023] A filter system according to the invention is also advantageous in which the at least one test point is located in the ground path of the power supply path, wherein the electronic data processing device is preferably connected to a shunt resistor at the test point. The electronic data processing device is configured to detect the current flow and / or the electrical voltage through the shunt resistor through software evaluation.

[0024] The filter system according to the invention is further advantageously further developed by an electrical supply module, which is connected to the at least one contacting element of the insert receptacle and is configured to supply current to the conductor track arrangement of the filter insert. The current supply to the current supply path is preferably supplied via a current control. For example, the current supply path is supplied via the current control of a high-voltage source. The current control can specify an output current setpoint, which is then regulated. The current control can, for example, specify an output current setpoint at an ionizer connected in parallel, and the associated high-voltage voltage is regulated accordingly. The output current setpoint of an ionizer is, for example, 10 pA, and the resulting voltage is between 4 and 10 kV. A current intensity is set for this purpose depending on the resistances in the remaining current supply path.Alternatively, the power supply path is supplied via voltage regulation.

[0025] Advantageously, the supply module can supply the filter insert and a parallel ionizer with the same voltage, whereby the voltage applied across the polarizable filter medium is reduced from the high voltage to the desired polarization voltage by resistors in the conductor arrangement of the filter insert. Alternatively, the supply module can also supply the ionizer with the high voltage required for ionization and the polarization filter separately with the desired polarization voltage.

[0026] In another alternative embodiment, the supply module can also supply the ionizer with the high-voltage required for ionization and the polarization filter separately with an intermediate voltage between the high-voltage voltage and the desired polarization voltage, which is then reduced from the intermediate voltage to the desired polarization voltage by resistors in the conductor arrangement of the filter insert. For example, in a high-voltage source in which the high-voltage voltage is generated from a lower voltage using a cascade circuit, an intermediate voltage from the cascade of the high-voltage source can be used.

[0027] The object underlying the invention is further achieved by a method of the type mentioned at the outset, wherein, within the scope of the method according to the invention, a current flow and / or an electrical voltage at at least one test point of the current supply path is evaluated by means of an electronic data processing device to detect a faulty operating state and / or a functional impairment of the filter system. The method according to the invention is preferably used to test a filter system according to one of the embodiments described above. Alternatively, the method according to the invention is used to test a filter system with a filter insert according to one of the embodiments described above. With regard to the advantages and modifications by means of the method according to the invention, reference is therefore made to the advantages and modifications of the filter system according to the invention and the advantages and modifications of the filter insert according to the invention.

[0028] Preferred embodiments of the invention are explained and described in more detail below with reference to the accompanying drawings.

[0029] Fig. 1 shows a filter insert according to the invention in a schematic perspective view;

[0030] Fig. 2 shows the layer composite of the filter insert shown in Fig. 1 in a schematic sectional view; and

[0031] Fig. 3 shows a schematic representation of a filter system according to the invention. Fig. 1 shows a filter insert 10 of a filter system 100 that can be used in a motor vehicle. The filter system 100 serves, for example, as an interior air filter of the motor vehicle.

[0032] The filter insert 10 comprises a pleated layer composite 12 consisting of several layers. The layer composite 12 comprises a filter medium 14, which is designed as an electrically insulating filter layer. The layer composite 12 further comprises two polarization electrodes 16a, 16b designed as electrically conductive polarization layers. Material strips 18a, 18b run along the lateral outer edges of the pleated layer composite 12. The material strips 18a, 18b form the side laminations of the filter insert 10 and are integrally bonded, e.g., glued, to the pleated layer composite 12.

[0033] The filter insert 10 comprises a contact element 20 for electrically contacting the filter insert 10. The contact element 20 is arranged in sections on the lateral material strip 18a of the filter insert 10. The contact element 20 is a contact label adhered to the lateral material strip 18a. The contact element 20 carries a conductor track arrangement 22. The conductor track arrangement 22 is electrically conductively connected to the polarization electrodes 16a, 16b and can be electrically contacted via the contact fields 24a, 24b with a contact element on the insert receptacle side.

[0034] The electrically conductive conductor track arrangement 22 comprises a first conductor track 26a and a second conductor track 26b, which are supported by a contact tab 28 of the contacting element 20. The contact tab 28 extends beyond the lateral material strip 18a along the polarization electrode 16a. The conductor tracks 26a, 26b are connected to the polarization electrode 16a at the contact points 32a, 32b via fixing elements 30a, 30b formed as cured adhesive strips. The double contacting of the polarization electrode 16a allows the current flow to be conducted via the polarization electrode 16a. Due to this current conduction, a current flow only occurs when the conductor tracks 26a, 26b of the contact tab 28 are properly connected to the polarization electrode 16a. This ensures that the polarization voltage is coupled in and thus the filter medium 14 is properly polarized.

[0035] On the underside of the filter insert 10 (not shown), the electrically conductive conductor track arrangement 22 also comprises a first conductor track 34a and a second conductor track 34b, which are supported by a contact tab 36 of the contacting element 20. The contact tab 36 extends beyond the lateral material strip 18a along the polarization electrode 16b. The conductor tracks 34a, 34b are connected to the polarization electrode 16b at the contact points 40a, 40b via fixing elements formed as cured adhesive strips. Due to the double contacting of the polarization electrode 16b, the current flow can be guided via the polarization electrode 16b. Due to this current conduction, a current flow only occurs when the conductor tracks 34a, 34b of the contact tab 36 are properly connected to the polarization electrode 16b.This ensures that the polarization voltage is coupled in and thus the filter medium 14 is properly polarized.

[0036] Figure 2 shows that the polarization electrode 16a is designed as the upper polarization layer, while the polarization electrode 16b is designed as the lower polarization layer. The polarizable filter medium 14, designed as a filter layer, is located between the polarization electrodes 16a, 16b, which are designed as polarization layers.

[0037] Fig. 3 shows a filter system 100 with a filter insert 10. The filter insert 10 has a layered composite 12 made of a polarizable filter medium 14 and two polarization electrodes 16a, 16b. The filter system 100 further comprises an insert receptacle (not shown) which has two contacting elements 118a, 118b, via which a conductor track arrangement 22 of the filter insert 10, which is electrically conductively connected to the polarization electrodes 16a, 16b of the filter insert 10, is electrically contacted. For this purpose, the filter insert 10 has contact fields 24a, 24b, which are in contact with the contacting elements 118a, 118b of the insert receptacle. The filter system 100 also has an electrical supply module 102, a power supply path 104, an ionizer 106, and an electronic data processing device 116. The electronic supply module 102 is used to supply power to the filter insert 10 and to supply power to the ionizer 106.The supply module 102 provides a high voltage to the ionizer 106 via the power supply path 104. The high voltage is also applied to the contact pads 24a, 24b of the filter insert 10 via the contact elements 118a, 118b. A reduced voltage is applied to the polarization electrodes 16a, 16b of the pleated layer composite 12 via a voltage divider 42.

[0038] The electronic data processing device 116 is configured to evaluate the current flow at the test point 112 of the power supply path 104 to detect a faulty operating state and / or a functional impairment of the filter system 100. The test point 112 is located in the ground path 110 of the power supply path 104, with the electronic data processing device 116 being connected to a shunt resistor 114 at the test point 112. The data processing device 116 detects the presence of a current flow through the shunt resistor 114.

[0039] The electrically conductive conductor track arrangement 22 is supported by a contacting member 20. The contacting member 20 has two contacting tabs 28, 36. The conductor tracks 26a, 26b are partially supported by the contacting tab 28. The conductor track 26a is electrically conductively connected to the polarization electrode 16a at the contacting point 32a. The conductor track 26b is electrically conductively connected to the polarization electrode 16a at the contacting point 32b. The conductor tracks 34a, 34b are partially supported by the contacting tab 36. The conductor track 34a is electrically conductively connected to the polarization electrode 16b at the contacting point 40a. The conductor track 34b is electrically conductively connected to the polarization electrode 16b at the contacting point 40b.

[0040] The electrically conductive conductor arrangement 22 is thus electrically conductively connected to the polarization electrode 16a at two spaced-apart contact points 32a, 32b and electrically conductively connected to the polarization electrode 16b at two spaced-apart contact points 40a, 40b. The supply path 108 of the power supply path 104 thus runs via the polarization electrode 16a. The ground path 110 of the power supply path 104 thus runs via the polarization electrode 16b. The polarization electrode

[0041] 16a, 16b are therefore used as part of the current path. Thus, the contacting of the polarization electrode 16a in the supply path as well as the contacting of the polarization electrode 16b in the ground path 110 can be checked by the electronic data processing device 116 using current flow analysis. The voltage divider 42 of the filter insert 10 comprises useful resistors R1 to R6, which are formed by electrically conductive resistance paths.

[0042] Reference symbol

[0043] 10 filter inserts

[0044] 12 layer composite

[0045] 14 Filter medium

[0046] 16a, 16b polarization electrodes

[0047] 18a, 18b material strips

[0048] 20 contact element

[0049] 22 Conductor track arrangement

[0050] 24a, 24b Contact fields

[0051] 26a, 26b Conductor tracks

[0052] 28 Contact tab

[0053] 30a, 30b Fixing elements

[0054] 32a, 32b contact points

[0055] 34a, 34b Conductor tracks

[0056] 36 Contact tab

[0057] 40a, 40b contact points

[0058] 42 voltage dividers

[0059] 100 filter system

[0060] 102 supply module

[0061] 104 Power supply path

[0062] 106 Ionizer

[0063] 108 Supply path

[0064] 110 Ground path

[0065] 112 Testing center

[0066] 114 Shunt resistance

[0067] 116 Data processing facility

[0068] 118a, 118b Contact elements

[0069] R1-R6 useful resistors

Claims

Claims 1. A filter insert (10) for insertion into an insert receptacle of a filter system (100), comprising a polarizable filter medium (14) through which a fluid to be filtered can flow; at least one polarization electrode (16a, 16b) for polarizing the filter medium (14); and at least one electrically conductive conductor track arrangement (22) which is electrically conductively connected to the polarization electrode (16a, 16b) and can be electrically contacted with a contacting element (118a, 118b) on the insert receptacle side. characterized in that the electrically conductive conductor track arrangement (22) comprises a first conductor track (26a, 34a) which is electrically conductively connected to the polarization electrode (16a, 16b) at a first contact point (32a, 40a), and a second conductor track (26b, 34b) which is connected to the polarization electrode (16a, 16b) at a second contact point (32b, 40b).

2. Filter insert (10) according to claim 1, characterized in that the first contact point (32a, 40a) and the second contact point (32b, 40b) are located on the same side of the polarization electrode (16a, 16b).

3. Filter insert (10) according to claim 1 or 2, characterized in that the distance between the first contact point (32a, 40a) and the second contact point (32b, 40b) is less than 10 cm.

4. Filter insert (10) according to one of the preceding claims, characterized in that the first conductor track (26a, 34a) is connected to a contact field (24a, 24b) via which the filter insert (10) can be electrically conductively contacted with the insert-side contacting element (118a, 118b).

5. Filter insert (10) according to one of the preceding claims, characterized in that the conductor track arrangement (22) is at least partially a component of a contacting element (20) serving for electrical contacting of the filter insert (10), wherein the contacting element (20) is preferably arranged at least in sections on a lateral material strip (18a, 18b) of the filter insert (10).

6. Filter insert (10) according to claim 5, characterized in that the contacting member (20) has a contacting tab (28, 36) which extends beyond the lateral material strip (18a, 18b) and / or along the polarization electrode (16a, 16b), wherein the contacting tab (28, 36) comprises at least one contacting section of the first conductor track (26a, 34a), which is electrically conductively connected to the polarization electrode (16a, 16b) at the first contacting point (32a, 40a), and at least one contacting section of the second conductor track (26b, 34b), which is connected to the polarization electrode (16a, 16b) at the second contacting point (32b, 40b).

7. Filter insert (10) according to claim 5, characterized in that the contacting member (20) has a first contacting tab extending beyond the lateral material strip (18a, 18b) and / or along the polarization electrode (16a, 16b), which comprises at least one contacting section of the first conductor track (26a, 34a), which is electrically conductively connected to the polarization electrode (16a, 16b) at the first contacting point (32a, 40a), and a second contacting tab extending beyond the lateral material strip (18a, 18b) and / or along the polarization electrode (16a, 16b), which comprises at least one contacting section of the second conductor track (26b, 34b) which is electrically conductively connected to the polarization electrode (16a, 16b) at the second contacting point (32b, 40b).

8. Filter insert (10) according to one of the preceding claims, characterized by two spaced-apart polarization electrodes (16a, 16b) for polarizing the filter medium (14); wherein the conductor track arrangement (22) is electrically conductively connected to the polarization electrodes (16a, 16b) and can be electrically contacted with contact elements (118a, 118b) on the insert receptacle side.

9. Filter insert (10) according to claim 8, characterized in that the electrically conductive conductor track arrangement (22) is electrically conductively connected to a first polarization electrode (16a) at two contact points (32a, 32b) spaced apart from one another and is electrically conductively connected to a second polarization electrode (16b) at two contact points (40a, 40b) spaced apart from one another.

10. Filter insert (10) according to one of the preceding claims, characterized in that the electrically conductive conductor track arrangement (22) and / or the at least one polarization electrode (16a, 16b) are components of a voltage divider (42) or form a voltage divider (42).

11. Filter insert (10) according to one of the preceding claims, characterized in that the polarizable filter medium (14) is designed as an electrically insulating filter layer; and / or the at least one polarization electrode (16a, 16b) is designed as an electrically conductive polarization layer.

12. Filter insert (10) according to one of the preceding claims, characterized in that the at least one polarization electrode (16a, 16b) and the filter medium (14) form a multi-layer pleated composite layer (12).

13. A filter system (100) comprising a filter insert (10) with a polarizable filter medium (14) and at least one polarization electrode (16a, 16b), and an insert receptacle having at least one contacting element (118a, 118b) via which a conductor track arrangement (22) of the filter insert (10) that is electrically conductively connected to the polarization electrode (16a, 16b) of the filter insert (10) can be electrically contacted; characterized in that the filter insert (10) is designed according to one of the preceding claims.

14. Filter system (100) according to claim 13, characterized by a current supply path (104) in which the conductor track arrangement (22) of the filter insert (10) is integrated, wherein the filter system (100) has an electronic data processing device (116) which is designed to evaluate a current flow and / or an electrical voltage at at least one test point (112) of the current supply path (104) for detecting a faulty operating state and / or a functional impairment of the filter system (100).

15. Filter system (100) according to claim 14, characterized in that the at least one test point (112) is located in the ground path (110) of the power supply path (104), wherein the electronic data processing device (116) is preferably connected to a shunt resistor (114) at the test point (112).

16. Filter system (100) according to one of claims 13 to 15, characterized by an electrical supply module (102) which is connected to the at least one contacting element (118a, 118b) of the insert receptacle and is designed to supply current to the conductor track arrangement (22) of the filter insert (10).

17. A method for testing a filter system (100) comprising a replaceable filter insert (10), in particular a filter system (100) according to one of claims 13 to 16 or a filter system (100) with a filter insert (10) according to one of claims 1 to 12, comprising the step: Energizing a power supply path (104) of the filter system (100) for polarizing a polarizable filter medium (14) of the filter insert (10) via at least one polarization electrode (16a, 16b) of the replaceable filter insert (10); characterized by the step: Evaluating a current flow and / or an electrical voltage at at least one test point (112) of the power supply path (104) by means of an electronic data processing device (116) to detect a faulty operating state and / or a functional impairment of the filter system (100).

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