Test strips for measuring the concentration of peracetic acids and methods for coating a test strip

Abstract

The invention relates to a test strip (700, 710, 720, 730) for measuring the concentration of peracetic acid. The invention further relates to a method (1000) for coating a test strip (703, 723, 730) for measuring the concentration of peracetic acid with a coating (703, 723, 733). The test strip for measuring the concentration of peracetic acid comprises a test area (702) configured to react with a liquid containing peracetic acid and covered with a coating (703, 723, 733).

Description

TECHNICAL FIELDThe invention relates to a test strip for measuring a concentration of peracetic acids. The invention further relates to a method for providing a test strip with a coating for measuring a concentration of peracetic acids.BACKGROUNDTest strips, in particular test strips for measuring a concentration of peracetic acids, are frequently used in analytical instruments for detecting cleaning, sterilizing and / or disinfecting agents. Such analysis devices can be used, for example, in water-conducting domestic appliances which are known, for example, from DE 102009027950 A1. This document relates to a household appliance having a control device for carrying out wash cycles which are adjusted by the control device using cleaning agents, e.g. additives. An evaluation unit detects the cleaning agents and is provided with a reading unit for radio frequency identification of bar codes or other identification features printed on the cleaning agents. The analysis unit is connected to the control device in order to transmit analysis data from the analysis unit to the control device.Furthermore, EP 3302210 B1 discloses an apparatus and a method for determining the composition of the dirt load in a washing or washing agent solution in a water-conducting domestic appliance, for example in a dishwasher, by means of near infrared spectroscopy (NIR).Patent application DE 19806559 B4 discloses a method in which beams are emitted into a dish stack, a quantity or beams of at least one wavelength range are determined and / or recorded, which leave the stack at a respective predetermined angle, a type and a concentration of a contamination portion and / or a cleaner portion of the dish stack is assumed and a dishwasher program is optimized accordingly. A corresponding dishwasher arrangement is also disclosed.Patent application DE 102007011119 A1 relates to a washing machine with an automatic control for the washing process and optical sensor devices. The optical sensor devices emit signals which are evaluated for controlling the washing process. The optical sensor devices record light intensities of different spectral ranges. The optical sensor devices are sensitive over the entire spectral range from infrared to ultraviolet. The optical sensor devices are arranged on a bypass, so that the optical sensor devices measure properties of detergent components at different positions.However, existing solutions for using test strips for measuring peracetic acid concentration in analytical instruments for detecting cleaning, sterilizing and / or disinfecting agents are generally comparatively expensive and frequently require the use of special chemicals. Moreover, the existing solutions are often operated wholly or partly manually and / or are not always accurate and robust with respect to operating errors. In particular, the test strips present are often not suitable or not reliable enough for certain fields of application.SUMMARYIt is therefore an object of the present invention to provide a solution which reduces or eliminates one or more of the above disadvantages. In particular, it is an object of the present invention to provide an improved test strip and an improved method for producing the test strip, in particular a test strip, which are reliable, cost-effective and less susceptible to storage and operating errors.According to a first aspect, there is provided a test strip for measuring a concentration of peracetic acids, comprising a test area configured to react with a liquid containing peracetic acids and covered with a coating.The test strip described here is suitable in particular for measuring a concentration of processing agents in a processing liquid which is used in a processing device for medical instruments, in particular in an evaluation unit, preferably a unit which comprises or consists of an optical spectrometer and / or an RGB color sensor, of a measurement system of an arrangement for measuring a concentration of processing agents in a processing liquid which is used in a processing device for medical instruments.The processing used herein may include all the steps required to re-use previously used medical instruments, including removal of blood, tissue and other biological debris, as well as inactivation of infectious microorganisms and / or viruses. In particular, the conditioning may include, but is not limited to, initial basic cleaning and subsequent thorough cleaning and / or disinfection and / or sterilization of medical instruments with suitable cleaning and / or disinfecting and / or sterilizing agents. The preparation may also include repackaging and final sterilization of the previously cleaned and / or disinfected and / or sterilized medical instruments. The processing agents may comprise processing chemicals, for example peracetic acid. A conditioning cycle may include a method performed, for example, in a conditioning apparatus to refurbish a medical instrument between two uses. A conditioning cycle may include a method for cleaning and / or rinsing and / or disinfection and / or sterilization.Medical instruments as used herein include, for example, endoscopes and / or probes, in particular reusable medical instruments such as reusable endoscopes and / or reusable probes.The treatment of medical instruments is particularly sensitive to the safety of medical procedures using such medical instruments and there are therefore the highest demands on the reliability of this treatment. In particular, the requirements for the treatment of medical instruments differ significantly from those for water-conducting domestic appliances, such as dishwashers and washing machines, and go far beyond this. Therefore, solutions for such water-conducting domestic appliances are not suitable or sufficient for the requirements for the preparation of medical instruments between different medical interventions on different patients.In the following, first the test strip for measuring a concentration of peracetic acids and its components, functions and advantageous embodiments are described.The present test strip has a test area configured to react with a peracetic acid-containing liquid. As a result, the test strip is suitable for measuring the concentration of processing agents in a processing liquid. Furthermore, the test surface is covered with a coating. This coating preferably serves to protect the test surface, in particular from unfavourable environmental conditions which occur during storage and / or use and which can impair the test accuracy.The test strip for measuring peracetic acid concentration has several advantages. For example, the test strips are a cost effective way to measure peracetic acid concentration during or after a conditioning cycle. Moreover, they are easy for human personnel to handle or can be used with special machines.Preferably, the coating of the test strip is designed to measure a concentration of peracetic acids in order to reduce the reactivity of the test area with the ambient and / or air humidity. This has the advantage that the test strip is protected during storage from ambient moisture, which can particularly impair the test accuracy and even make the test strip unusable.According to a preferred embodiment, the coating of the test strip for measuring a concentration of peracetic acids is a film. The use of a film coating has the advantage that an easily processable material is used. Film material also has the advantage that it is easy to handle and apply. Moreover, a method of applying a film coating may be open to the use of different types of films having different properties, so that the protective properties of the film coating may be easily adapted to the requirements of particular application areas.It is preferred that the coating of the test strip for measuring peracetic acid concentration comprises or consists of a liquid-soluble material, in particular a water-soluble material, and / or the coating comprises or consists of a biodegradable material. This embodiment has the advantage that measurement is possible after the test strip has been immersed in a liquid or has been exposed to it for a certain period of time.In a further preferred embodiment, the coating of the test strip for measuring a concentration of peracetic acids consists of polyvinyl alcohol or the coating of the test strip for measuring a concentration of peracetic acids comprises polyvinyl alcohol. This is an advantageous and cost-effective material.Preferably, the coating of the test strip for measuring a concentration of peracetic acids covers at least a part of a side of the test strip, in particular a part of the side of the test strip which contains the test area. This is advantageous for protecting the test surface without excessive material usage for the coating.Preferably, the coating of the test strip for measuring a concentration of peracetic acids covers at least a part of the test strip surrounding the test area. This embodiment has the advantage that only a minimum or minimal amount of material is required for the coating.In a further preferred embodiment, the coating of the test strip for measuring a concentration of peracetic acids covers all sides of the test strip along a length section of the test strip which contains the test area. In particular, it may be preferred that the coating of the test strip for measuring a concentration of peracetic acids covers the entire test strip, in particular all sides of the entire test strip.This has the advantage that the test surface is particularly well protected from external influences, such as moisture. Furthermore, it can be advantageous if the test strip or at least a part of the test strip with the test area is immersed in liquid coating material for applying the coating.In further preferred embodiments, the length section of the test strip covered by the coating for measuring a concentration of peracetic acids is at least 5% of the total length of the test strip, preferably at least 10%, preferably at least 15%, preferably at least 20%, preferably at least 25%, preferably at least 30%, preferably at least 40%.In further preferred embodiments, the length section of the test strip covered by the coating for measuring a concentration of peracetic acids is at most 80% of the total length of the test strip, preferably at most 75%, preferably at most 70%, preferably at most 60%, preferably at most 50%, preferably at most 40%, preferably at most 30%.Individual or all embodiments of a test strip for measuring the concentration of peracetic acids may have several advantages. In general, embodiments relating to a test strip provide a convenient method of measuring the concentration of peracetic acids or other cleaning and / or disinfecting and / or sterilizing agents in a liquid. In particular, the embodiments relating to a test strip offer a possibility of measuring the cleaning and / or disinfecting and / or sterilizing agents in a liquid after a certain period of time. Moreover, the test strip embodiments can even be stored in environments that normally have a negative impact on the test strips in general and the test area in particular.According to a second aspect, there is provided a method of providing a test strip for measuring a concentration of peracetic acids with a coating, comprising providing a test strip having a test area configured to react with a liquid and covering the test area with a coating.Details, functions and advantageous embodiments of the method and of the arrangement for coating a test strip for measuring the concentration of peracetic acids are described below.Preferably, the method of coating a test strip for measuring a concentration of peracetic acids further comprises liquifying a coating material and dipping the test strip into the liquid coating material until the test area is fully dipped. In this way, the test area is completely covered with the coating material.In a further preferred embodiment, the method for coating a test strip for measuring a concentration of peracetic acids comprises keeping the test area immersed in the liquid coating material for a predetermined period of time and / or pulling the test strip out of the liquid coating material and / or drying the liquid coating. This embodiment has the advantage that the test surface is completely and uniformly covered with the coating material.In particular, it may be preferred that the method for providing a test strip for measuring a concentration of peracetic acids with a coating comprises applying a coating in the form of a film to at least part of one side of the test strip, in particular part of the side of the test strip containing the test area, preferably in assembly line production, in particular in semi- or fully automatic assembly line production. This has the advantage that the test area is completely covered with the coating material without the risk of heat-induced damage to the test strip.With regard to the advantages, preferred embodiments and details of the aspects according to the invention and their preferred embodiments, reference is made to the advantages, preferred embodiments and details described below. In particular, the advantages, preferred embodiments and details described herein apply analogously to all aspects of the invention mentioned herein.Further advantageous embodiments of the above-described method and test strips may be realized by the combination of some or all of the preferred features described herein.According to a further aspect, there is provided an assembly line configured to provide test strips for measuring a concentration of cleaning and / or disinfecting and / or sterilizing agents in a liquid, in particular peracetic acid, according to one or more of the embodiments described above. In particular, embodiments of the test strip in which the coating covers at least a part of the test strip surrounding the test area, or in which the coating covers at least a part of the side of the test strip containing the test area, or in which the coating covers all sides of the test strip along a length section of the test strip containing the test area, are produced in the same production line. This includes either covering the test area by keeping the test area immersed in the liquid coating material for a period of time, or applying a coating in the form of a film to at least a portion of a side of the test strip containing the test area, resulting in one of the embodiments described above.Regarding the advantages, preferred embodiments and details of the individual different aspects and their preferred embodiments, reference is also made to the corresponding advantages, preferred embodiments and details which are described with reference to the respective other aspects.Further advantageous embodiments result from the combination of individual, several or all of the preferred features described here.BRIEF DESCRIPTION OF THE DRAWINGSPreferred embodiments will now be described with reference to the accompanying drawings, in which FIG. 1 shows a schematic representation of an exemplary treatment device for medical instruments according to the prior art; FIG. 2 shows a schematic representation of an exemplary embodiment of a treatment device for medical instruments; FIG. 3 is a schematic detailed view of an arrangement for measuring a concentration of processing agents in a processing liquid used in the medical instrument processing apparatus of FIG. 2 ; Figures 4a-c show cross-sections of three preferred embodiments of a test strip for measuring peracetic acid concentration; FIG. 5 shows a three-dimensional view of the first embodiment 710 according to FIG. 4 a; FIG. 6 shows a three-dimensional exploded drawing of the second embodiment 720 according to FIG. 4 b; FIG. 7 : shows a three-dimensional view of the third embodiment 730 according to FIG. 4 c; and FIG. 8 shows a schematic flow diagram of a method for coating a test strip for measuring the concentration of peracetic acids.DETAILED DESCRIPTIONIn the figures, elements having the same or comparable functions are denoted by the same reference numerals.FIG. 1 shows a schematic representation of an exemplary treatment device 90 for medical instruments 20, e.g. endoscopes, according to the prior art. The device 90 can comprise a treatment chamber 18, into which a load carrier 21 with medical instruments 20 to be cleaned and / or disinfected and / or sterilized can be introduced. The treatment liquid can circulate in the device 90 via a circulation pump 13 and a pump sump 14 in an outer treatment circuit 11 and an inner treatment circuit 12. The outer treatment circuit 11 can circulate the treatment liquid in the treatment chamber 18 via at least one, but preferably two, spray arms 19. The inner treatment circuit 12 can conduct the treatment liquid via the monitoring unit 25, the load carrier 21 and the load carrier coupling 23 to the inner channels of the medical instruments 20 located in the load carrier 21. For metering processing agents into the processing liquid in the processing chamber 18, a metering system 24 can be provided. The sump 14 may be connected to a drain pump 15 which in turn may be connected to a check valve 16 and a structural drain 17.The inner treatment circuit 12 connects the load carrier 21 to the structural drain 17. the inner treatment circuit 12 may comprise a monitoring unit 25 which may be connected to the load carrier 21 via a load carrier coupling 23 comprising an adapter plate 22. The monitoring unit 25 can furthermore be connected to the circulation pump 13 and thus to the elements following the circulation pump, namely the discharge pump 15, the check valve 16 and the structural drain 17.FIG. 2 shows a schematic representation of an exemplary embodiment of a treatment device 1 for medical instruments 20, e.g. endoscopes. The treatment device 1 can also comprise a treatment chamber 18, into which a load carrier 21 with medical instruments 20 to be cleaned and / or disinfected and / or sterilized can be introduced. The treatment liquid can circulate in the treatment device 1 via a circulation pump 13 and a pump sump 14 in an outer treatment circuit 11 and an inner treatment circuit 12. The outer treatment circuit 11 can circulate the treatment liquid in the treatment chamber 18 via at least one, but preferably two, spray arms 19. The inner treatment circuit 12 can conduct the treatment liquid via the monitoring unit 25, the load carrier 21 and the load carrier coupling 23 to the inner channels of the medical instruments 20 located in the load carrier 21. For metering processing agents into the processing liquid in the processing chamber 18, a metering system 24 can be provided. The sump 14 may be connected to a drain pump 15 which in turn may be connected to a check valve 16 and a structural drain 17.The inner treatment circuit 12 connects the load carrier 21 to the structural drain 17. the inner treatment circuit 12 may comprise a monitoring unit 25 which may be connected to the load carrier 21 via a load carrier coupling 23 comprising an adapter plate 22. The monitoring unit 25 can furthermore be connected to the circulation pump 13 and thus to the elements following the circulation pump, namely the discharge pump 15, the check valve 16 and the structural drain 17.The processing device 1 differs from existing processing devices 90 in particular in an arrangement 10 for measuring a concentration of processing agents in a processing liquid and a compressed air supply 204.FIG. 3 shows a schematic representation in detail of an arrangement 10 for measuring a concentration of treatment agents in a treatment liquid which is used in the treatment device 1 for medical instruments from FIG. 2.The arrangement 10 comprises a measuring system 100 which is connected via a first line 120 for the hydraulic connection of the measuring system to the treatment circuits 11, 12, in particular to the circulation pump 13. Furthermore, the measuring system 100 is connected to the treatment chamber 18 via a second line 130 for a bypass connection. The first and second conduits preferably form a bypass circuit for the treatment liquid that is passed through the measurement system 100. The measuring system 100 can furthermore be connected to a compressed air supply 204.During operation of the device 1, one or more medical instruments 20 are placed in the load carrier 21 and connected via the adapter plate 22 and the load carrier coupling 23 to the inner treatment circuit 12 in order to flush the inner channel or channels of the medical instrument or instruments 20 with treatment liquid.The treatment chamber 18 can be filled with treatment liquid containing a preferred treatment agent by means of spray arms 19 via the outer treatment circuit 11. The treatment chamber 18 may contain the treatment liquid for a predetermined period of time. Alternatively and / or additionally, the circulation pump 13 can be used to circulate the treatment liquid containing the treatment agent again by pumping it via the circulation pump 13 from the pump sump 14 to the spray arms 19 in the outer treatment circuit 11 and / or to the inner channel / channels of the medical instrument / instruments 20 in the inner treatment circuit 12 for a predetermined period of time and / or number of cycles.During the cycle, processing liquid may be withdrawn from the outer processing circuit 11 via the first conduit 120 for delivery to the measurement system 100, where the concentration of the processing agent in the processing liquid is measured.The dosing unit 24 can supply additional preparation material according to the measurements of the measuring system 100. After measuring the concentration of the treatment agent, the remaining treatment liquid can be returned via the second line 130 into the outer treatment circuit 11.At the end of a treatment operation, in particular after a predetermined time and / or number of recirculation cycles with a required concentration of treatment agents in the treatment liquid, the treatment chamber 18 can be emptied via the structural drain 17 by using the discharge pump 15 to pump the time duration of liquid through the check valve 16 into the structural drain 17.The measurement system 100 may be arranged outside a housing of the device 1 or may have an interface on an outer periphery of the device 1.The measurement system 100 is configured to receive a test strip 700 having a test area 702 and to position the test strip 700 in a first dosing position A and a second measurement position B, both of which lie along a test strip guide 570, as can be seen in FIG. 3. The measuring system 100 is further configured to dose a defined amount of treatment liquid onto the test surface 702 via a treatment liquid feed system and a sample feed line 101 connected thereto when positioning the test strip 700 in the first dosing position A.The measuring system 100 preferably comprises an evaluation unit 102 for measuring the concentration of treatment agents in the treatment liquid when the test strip 700 is positioned in the second measuring position B by evaluating the test surface 702. The evaluation unit 102 can comprise or consist of an optical spectrometer and / or an RGB color sensor, and the evaluation unit 102 can be configured to compare the evaluation result with a reference value. For example, a feature, in particular a color feature, of the test area 702 can be determined and compared with a reference feature. The defined amount of treatment liquid can act on the test surface 702 for a defined exposure time before the test surface 702 is evaluated. After the evaluation of the test area 702, the test strip 700 is released.The arrangement 10 for measuring a concentration of processing agents in a processing liquid used in a processing device 1 for medical instruments 20 further preferably comprises a transport arrangement 300 for transporting a test strip 700. The transport assembly 300 may be used to transport a test strip 700. In particular, it is generally preferred within the scope of the present description that a single test strip 700 is transported.The arrangement 10 for measuring a concentration of processing agents in a processing liquid used in a processing device 1 for medical instruments 20 further preferably comprises a processing liquid supply system 200 for dosing a defined amount of processing liquid onto a test surface 702 of a test strip 700.FIGS. 4 a- c, 5, 6 and 7 show three exemplary embodiments 710, 720, 730 of the test strip 700 for measuring a concentration of peracetic acids. In each embodiment, the test strip for measuring a concentration of peracetic acids includes a test strip main body 701, a test area 702, and a coating 703, 723, 733.The main body 701 may be made of a suitable material, for example, plastic or cardboard. The main body 701 may be sized and shaped so as to be easily handled by persons or machines feeding the test strip 710, 720, 730. In a preferred embodiment, the main body 701 may be sized such that the test strip 710, 720, 730 may be used in a medical instrument treatment device 100, as exemplarily shown in FIG. 1. For example, various embodiments of test strip 710, 720, 730 may be used in a measurement system 100 of a medical instrument treatment device 20. The test strip main body 701 may be configured in any suitable shape for this use. For example, the test strip main body 701 may have a shape of a square, a circle, or an oval. In a preferred embodiment, the test strip main body 701 has a rectangular shape. In a particularly preferred embodiment, the size of the test strip 710, 720, 730 is optimized for reading by the measurement system 100. The measurement system 100 can comprise, for example, a spectrometer and / or an RGB sensor.The test surface 702 of the test strip 710, 720, 730 can consist of a material which is sensitive to active ingredients in treatment liquids, in particular cleaning liquids and / or disinfecting liquids and / or sterilization liquids. In a particularly preferred embodiment, the test surface 702 is designed to react with peracetic acids contained in a cleaning liquid. A reaction of the test area 702 may be understood as a color change of the test area 702. In a preferred embodiment, the color of the test surface can change depending on the concentration of peracetic acids in a liquid. The test surface 702 can be designed to react with active ingredients in a treatment liquid, in particular a cleaning and / or disinfecting and / or sterilizing liquid, within a specific period of time.The test surface 702 may also be configured to react with other active agents used in cleaning and / or disinfecting and / or sterilizing liquids. For example, the test surface 702 may be configured to react with alcohols, chlorine, iodophors, hydrogen peroxide, quaternary ammonia compounds, or other sterilizing and / or disinfecting agents. The test pad 702 may also be configured to indicate the effectiveness of steam, ethylene oxide, dry heat, formaldehyde, or other sterilization methods.The test area 702 may cover a sufficient part of the test strip main body 701. For example, the test area 702 may cover at least 5%, preferably at least 10%, preferably at least 15%, preferably at least 20%, preferably at least 25%, preferably at least 30%, or preferably at least 40% of the total length of the test strip. For example, the test area 702 can cover a maximum of 80%, preferably a maximum of 75%, preferably a maximum of 70%, preferably a maximum of 60%, preferably a maximum of 50%, preferably a maximum of 40% or preferably a maximum of 30% of the total length of the test strip. The test area 702 may have a shape suitable for rendering the results accessible to human users and / or machine reading. For example, the test area 702 may be square, rectangular, or circular. Preferably, the shape and size of the test surface 702 are optimized for reading by an evaluation unit that is used in a measurement system 100 of a treatment device for medical instruments 20. In preferred examples, the evaluation unit comprises an optical spectrometer and / or an RGB color sensor. The evaluation unit can preferably also be configured to compare an evaluation result with a reference value.The test pad 702 may be connected to the main body 701 of the test strip 710, 720, 730 in various ways. For example, the test pad may be attached to the main body 701 of the test strip 710, 720, 730 using clamps, glue dots / strips, liquid adhesives, or other types of attachment. The test pad 702 may also be integrated into the main body 701 of the test strip during the manufacture of the test strip.A coating 703, 723, 733 may cover the test area 702 of the test strip 710, 720, 730.Preferably, the coating 703, 723, 733 is a film. The coating 703, 723, 733 may be configured to reduce the reactivity of the test surface with the ambient and / or air humidity. The coating 703, 723, 733 can comprise or consist of a material soluble in liquids. The coating 703, 723, 733 may further comprise or consist of a biodegradable material. For example, the coating 703, 723, 733 may contain or consist of pullulan, carrageenan or arabinoxylan. In a preferred embodiment, the coating 703, 723, 733 comprises polyvinyl alcohol or a material based on polyvinyl alcohol or the coating 703, 723, 733 consists of polyvinyl alcohol or a material based on polyvinyl alcohol. In a preferred embodiment, the coating 703, 723, 733 is soluble in liquids, in particular in water or in liquids which contain a substantial proportion of water. The coating 703, 723, 733 can be designed such that it can be immersed for a long time in liquids, in particular in water or in liquids which contain a considerable amount of water, before it dissolves.As will be described below, the coating 703, 723, 733 may also be formed to also cover a substantial portion of the main body 701 of the test strip 710, 720, 730.Figures 4a and 5 show a first preferred embodiment 710 of a test strip. FIG. 4 ashows a cross-sectional view of the first preferred embodiment 710, while FIG. 3 shows a three-dimensional view of the first preferred embodiment 710. This first preferred embodiment 710 includes a main body 701, a test pad 702 connected to one side of the main body, and a coating 703. In this embodiment, the coating 703 may cover the test area 702 and at least a part of the main body 701, in particular a part of the main body 701 surrounding the test area 702. For example, the coating 703 may cover the test surface 702 and a portion surrounding the test surface 702.FIGS. 4 band 6 show a second preferred embodiment 720. FIG. 4 bshows a cross-sectional view of the second preferred embodiment 720, while FIG. 6 shows a three-dimensional exploded view of the second preferred embodiment 720. This second preferred embodiment 720 comprises a main body 701, a test pad 702 connected to one side of the main body, and a coating 723. In this embodiment 720, the coating 723 may cover the test area 702 and at least a portion of the main body 701, particularly a substantial portion of the side of the main body containing the test area 702. For example, the coating may cover at least 50%, at least 60%, at least 70%, or at least 90% of the side of the main body of the test strip, including the test area 702. In a preferred embodiment, the coating 723 covers substantially the entire side of the main body of the test strip 701 including the test pad 702.Figures 4c and 7 show a third preferred embodiment 730. FIG. 4 cshows a cross-sectional view of the third preferred embodiment 730, while FIG. 7 shows a three-dimensional view of the third preferred embodiment 730. This third preferred embodiment 730 includes a main body 701, a test pad 702 connected to one side of the main body, and a coating 733. In this embodiment 730, the coating 733 may cover the test surface 702 and at least a part of the main body 701, in particular a substantial part of all sides of the main body along a length portion of the main body 701 containing the test surface 702. For example, the coating may cover at least 60%, at least 70%, or at least 90% of the main body 701 including the test area 702. In a preferred embodiment, the coating covers substantially 50% of the main body 701 of the test strip including the test area 702. In a further preferred embodiment, the coating 733 covers the entire test strip 720, in particular all sides of the entire test strip 720.FIG. 8 shows a schematic flow diagram of a method 1000 for providing a test strip 700, 710, 720, 730 with a coating 703, 723, 733 for measuring a concentration of peracetic acids. The method 1000 may comprise the step 1100 of providing a test strip main body 701 comprising a test surface 702 configured to react with a liquid containing at least traces of processing agents, in particular cleaning and / or disinfecting and / or sterilizing agents. The test strip 700, 710, 720, 730 may have any shape and size as described above.The method 1000 can further comprise the step 1200 of covering at least the test surface 702 with a coating 703, 723, 733.In a preferred embodiment, in particular in embodiment 730, the method 1000 can further comprise the step 1210 of liquefying the coating material.The coating material may be any material suitable to cover the test area 702 as described above. Preferably, the coating material comprises or consists of a liquid-soluble material, in particular a water-soluble material. In addition, the coating 703, 723, 733 can comprise or consist of a biodegradable material. In a particularly preferred embodiment, the coating material can comprise or consist of polyvinyl alcohol.To liquify the coating material, the coating material may be heated to temperatures of at least 200°C. The coating material may then be maintained at suitable elevated temperatures for a prolonged period of time.The method 1000 may further include the step 1211 of immersing the test strip in the liquefied coating material until the test pad 702 is completely immersed. The dipping may be done in any suitable manner, for example, by manual dipping or machine controlled dipping. Preferably, the test strip can be dipped into the liquefied coating material by machine-controlled dipping. For example, the test strip main body 701 having the test area 702 may be immersed for as long as at least 5%, preferably at least 10%, preferably at least 15%, preferably at least 20%, preferably at least 25%, preferably at least 30%, or preferably at least 40%, of the total length of the test strip main body 701 including the portion containing the test area 702 is immersed in the liquefied coating material. In another example, the test strip main body 701 with the test area 702 may be immersed in the liquefied coating material until a maximum of 80% of the total length of the test strip, preferably a maximum of 75%, preferably a maximum of 70%, preferably a maximum of 60%, preferably a maximum of 50%, preferably a maximum of 40%, or preferably a maximum of 30% of the total length of the test strip main body 701 including the part containing the test area 702, are immersed in the liquefied coating material. In another preferred embodiment, only the side of the test strip body 701 containing the test area 702 may be immersed in the liquefied coating material.The method 1000 may further include the step 1212 of maintaining the test surface 702 immersed in the liquid coating material for a predetermined period of time. The predetermined time period may be selected such that the test area 702 is completely covered with the liquefied coating material.The method 1000 may further comprise the step 1213 of pulling out the test strip main body 701 comprising the test area 702 from the liquid coating material. The pulling out of the test strip main body 701 from the liquefied coating material may be performed manually or by using machine-controlled pulling out. Preferably, the test strips can be pulled out by means of machine-controlled pulling.The liquefied coating material may also be dropped onto the test surface 702 of the test strip main body 701 by suitable means, so that the liquefied coating may cover the test surface 702 and at least a part of the main body 701, in particular a part of the main body 701 surrounding the test surface 702. Suitable means for dropping the liquified coating material may be syringes, pipettes, squeeze bottles or other suitable means for dispensing predetermined amounts of the liquified coating material onto test area 702 of the test strip.The method 1000 may further include the step 1214 of drying the liquid coating material after extraction from the liquefied coating material or after dropping the liquefied coating material onto the test surface. For example, the liquid coating material may be dried in air or in a dry gas. Drying the liquid coating material of the test strip may take a predetermined time.Steps 1210 to 1214 of method 1000 may preferably result in test strips according to embodiment 730. However, test strips according to embodiments 710 and 720 can also be produced with steps 1210 to 1214 of method 1000.In a further preferred embodiment, the method 1000 can alternatively or additionally comprise the step 1220 of applying the coating 703 in the form of a film to at least part of a side of the test strip main body 701, in particular to a part of the side of the test strip main body 701 which contains the test area 702. In a preferred embodiment 710, the film may be applied to the test area 702 and a portion of the main body surrounding the test area 702. In another preferred embodiment 720, the film may be applied to the side of the main body of the test strip that includes the test pad 702. For example, the film may cover at least 5%, preferably at least 10%, preferably at least 15%, preferably at least 20%, preferably at least 25%, preferably at least 30%, or preferably at least 40%, of the total length of the test strip including the test area 702. For example, the film can cover a maximum of 80%, preferably a maximum of 75%, preferably a maximum of 70%, preferably a maximum of 60%, preferably a maximum of 50%, preferably a maximum of 40%, or preferably a maximum of 30% of the total length of the test strip including the test area 702. Preferably, the film covers the entire side of the test strip main body 701 including the test area 702. In another example, the film may be wrapped around the test strip, either manually or by suitable machinery.Step 1200 of the method 1000 may further comprise the step 1221 of applying the film to the main body 701 of the test strip. For example, the film may be attached to the main body 701 of the test strip main body 701 by adhesive force alone or using clamps, adhesive spots / strips, liquid adhesives, or other attachment methods.The method 1000 is preferably carried out in assembly line production, in particular in semi-automatic or fully automatic assembly line production. In a particularly preferred embodiment, steps 1220 to 1221 of method 1000 are carried out in an assembly line production, in particular in a semi-automatic or fully automatic assembly line production.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedDE 102009027950 A1

[0002] EP 3302210 B1

[0003] DE 19806559 B4

[0004] DE 102007011119 A1

[0005]

Claims

A test strip (700, 710, 720, 730) for measuring a concentration of peracetic acids, comprising a test area (702) configured to react with a liquid containing peracetic acid and covered with a coating (703, 723, 733).Test strip (700, 710, 720, 730) according to at least one of the preceding claims, wherein the coating (703, 723, 733) is configured to reduce the reactivity of the test surface (702) with the ambient and / or air humidity.The test strip (700, 710, 720, 730) of at least one of the preceding claims, wherein the coating (703, 723, 733) is a film.Test strip (700, 710, 720, 730) according to at least one of the preceding claims, wherein - the coating (703, 723, 733) comprises or consists of a liquid-soluble material, in particular a water-soluble material; and / or - the coating (703, 723, 733) comprises or consists of a biodegradable material.Test strip (700, 710, 720, 730) according to at least one of the preceding claims, wherein the coating (703, 723, 733) comprises or consists of polyvinyl alcohol.The test strip (700, 710, 720, 730) according to at least one of the preceding claims, wherein the coating (703, 723, 733) covers at least a part of a side of the test strip (700, 710, 720, 730), in particular a part of the side of the test strip (700, 710, 720, 730) containing the test area (702).The test strip (700, 710, 720, 730) of at least one of the preceding claims, wherein the coating (703, 723, 733) covers at least a portion of the test strip (700, 710, 720, 730) surrounding the test area (702).The test strip (730) of at least one of the preceding claims, wherein the coating (733) covers all sides of the test strip (730) along a length of the test strip (730) containing the test area (702).The test strip (730) according to the preceding claim, wherein the length portion of the test strip (730) covered by the coating is at least 5% of the total length of the test strip, preferably at least 10%, preferably at least 15%, preferably at least 20%, preferably at least 25%, preferably at least 30%, preferably at least 40%.Test strip (730) according to at least one of the two preceding claims, wherein the length section of the test strip (730) covered by the coating is at most 80% of the total length of the test strip (730), preferably at most 75%, preferably at most 70%, preferably at most 60%, preferably at most 50%, preferably at most 40%, preferably at most 30%.The test strip (730) according to the preceding claim, wherein the coating (733) covers the entire test strip (730), in particular all sides of the entire test strip (730).Method (1000) for providing a test strip (700, 710, 720, 730) with a coating (703, 723, 733) for measuring a concentration of peracetic acids, comprising - providing (1100) a test strip main body (701) with a test area (702) configured to react with a liquid; - covering (1200) the test area (702) with a coating (703, 723, 733).Method (1000) according to the preceding claim, - liquefying (1210) a coating material (703, 723, 733); - dipping (1211) the test strip main body (701) into the liquid coating material until the test area (702) is completely dipped.Method (1000) according to at least one of the preceding claims 12-13, - keeping the test area (702) immersed in the liquid coating material (1212) for a predetermined period of time; and / or - pulling out (1213) the test strip main body (701) from the liquid coating material; and / or - drying (1214) the liquid coating material.Method (1000) according to at least one of the preceding claims 12 - 14, - applying (1220) a coating (703, 723, 733) in the form of a film to at least part of a side of the test strip (700, 710, 720, 730), in particular a part of the side of the test strip (700, 710, 720, 730) containing the test area (702), preferably in assembly line production, in particular in semi- or fully automatic assembly line production.

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