Method and system for inspecting a fuel cell stack

Abstract

A method and system for inspecting the fuel cell stack to count the unit fuel cell is provided. The method and system include a fuel cell stack comprising a plurality of unit fuel cells, wherein each unit fuel cell comprises a bipolar plate and a membrane electrode assembly arranged in a stacked configuration. The method for inspecting the fuel cell stack includes the steps of guiding the sound generating device across the fuel cell stack in the stacking direction so that the sound generating device contacts the unit fuel cells to generate a sound. Subsequently, the generated sound is recorded and stored as a sound file. This is followed by analysing the sound file for identifying at least one distinctive sound peak that determines the features of the fuel cell stack, as well as a system that includes the above said steps is provided.

Description

[0001] Method and system for inspecting a fuel cell stack

[0002] Description:

[0003] The present invention relates to a method for inspecting a fuel cell stack according to the preamble of claim 1, as well as a system for inspecting a fuel cell stack according to the preamble of claim 9.

[0004] Fuel cell systems provide decentralized power generation capabilities, enabling greater flexibility and scalability. A typical fuel cell stack configuration comprises alternatively arranged membrane electrode assemblies and bipolar plates, so called unit fuel cells. The bipolar plates include an anode plate and a cathode plate, which are attached to each other, wherein the membrane electrode assemblies separate adjacent bipolar plates, and wherein the membrane electrode assemblies comprise at least a cathode, an anode, and a membrane for reacting hydrogen and oxygen to electric energy and water.

[0005] A complete fuel cell stack may comprise up to 455 or more unit fuel cells with a cell pitch of approximately 1mm, arranged in a stacked configuration. Each unit fuel cell contributes to the overall performance of the stack. Any deviation in the number of unit fuel cell from the designated configuration can result in suboptimal utilization of the fuel cell stack, potentially reducing its efficiency and output. Therefore, knowing the accurate number of unit fuel cell is crucial for optimizing the efficiency of the fuel cell stack. Furthermore, the accurate number of fuel cell count ensures that the electrochemical reactions within the stack occur as intended, maximizing the conversion of chemical energy into electrical energy.

[0006] Traditional techniques for counting unit fuel cells involve manual inspections or indirect measurements. However, these methods require operators to physically inspect and count stacks, which is time-consuming and can lead to miscounting the cells within the stack. This miscounting can result in an inaccurate assessment of the overall stack health or improper planning for necessary repairs, which could cause disruptions in the proper functioning of the fuel cell stack. Another problem of the fuel cell stack is that, during the stacking of the unit fuel cells, there is a possibility that parts of the unit fuel cell are missing or misaligned. Consequently, a person skilled in the art does not only need to know the accurate number of unit fuel cells, but the accurate number of unit fuel cell parts, which is even more challenging when using conventional manual or indirect stack counting methods.

[0007] It is therefore object of the present invention to provide a simple and reliable method and system for counting and determining the accurate number of unit fuel cells and unit fuel cell parts in the stack.

[0008] This object is solved by a method for inspecting a fuel cell stack according to claim 1 and a system for inspecting a fuel cell stack according to claim 9.

[0009] In the following, a fuel cell stack comprises a plurality of unit fuel cells, wherein each unit fuel cell comprises at least a membrane electrode assembly and at least a bipolar plate arranged in a stacked configuration. Each membrane electrode assembly has an active area with the electrodes sandwiching a membrane and a subgasket that frames the membrane electrode assembly. A gas diffusion layer may be arranged between the bipolar plate and the membrane electrode assembly, wherein the gas diffusion layer may be attached to the membrane electrode assembly itself.

[0010] For providing a reliable method and system for counting the fuel cell unit and / or inspecting the fuel cell stack, the inventor has proposed to use the features of a sound file, wherein the sound file is created by contacting the unit fuel cells by means of a sound generating device.

[0011] Thus, the proposed method comprises the steps of: a. generating a sound by guiding a sound generating device along the fuel cell stack in such a way that the sound generating device contacts each unit fuel cells, b. recording the sounds generated by the sound generating device for creating a sound file, and c. analysing the sound file for determining at least one feature of the fuel cell stack.

[0012] Optionally, a result of the analysis is presented to a user, e.g. by means of a graphical user interface. Consequently, the system for performing the method comprises at least the respective devices, namely a sound generating device, a recording device and computing device for the analysis.

[0013] According to a preferred embodiment, the system may further comprise a storing device for storing the recorded sound file and / or a user interface, particularly a display device, for outputting a result of the analysis of sound file to a user.

[0014] All devices may be connected wirelessly or wired to each other, wherein the wireless connection is preferred. It is particularly preferred that the sound generating device is in wireless and / or in wired communication with the recording device, and / or the recording device is in wireless and / or in wired communication with the computing device.

[0015] The sound generating device itself may be any tool, instrument, device, or system configured to generates sound and / or vibration when contacting a material. Preferably, the sound generating device is a plectrum holder, piezo element or any deformable element that generates sounds and / or vibration when contacting a surface of a material.

[0016] The recording device may refer to a device or apparatus configured to record or capture and / or store a sound and / or vibration. The recording device may include various components such as sensors, transducers, processors, memory storage, and interfaces for input and output, and / or a microphone or any sound capturing unit to record the sounds.

[0017] The computing device may refer to an electronic device or any device or instrument or system or a machining learning system such as an artificial intelligence system configured to execute predefined sets of instructions.

[0018] According to an embodiment, analysing the sound file includes comparing at least one feature of the recorded sound file with a reference feature. By comparing the features with predetermined reference features, an easier recognition and interpretation of the corresponding features within the recorded sound file is enabled. Further, the simple comparison of the features of the recorded sound with a reference feature allows for an automatic determination of at least one feature of the fuel cell stack.

[0019] According to a preferred embodiment, the unit fuel cell comprises at least a membrane electrode assembly adapted to extend at least partly beyond the bipolar plates. This extended region of the membrane electrode assembly ensures that the bipolar plates are electrically isolated, preventing them from contacting each other, thus avoiding any short circuit in the fuel cell stack.

[0020] Preferably, the sound generating device contacts the extended region of at least one membrane electrode assembly to generate the sound. The extended region of the membrane electrode assembly that protrudes over the bipolar plate provides an optimal contact possibility for the sound generating device, as the generated sound can be used for accurately indicating features of the membrane electrode assembly, e.g., the presence and the number of membrane electrode assembly.

[0021] Additionally, depending on the actual arrangement of the membrane electrode assembly in relation to the bipolar plate, i.e. , depending on how far the membrane electrode assembly is extending over the bipolar plate, the sound generated by the sound generating device upon contact with the membrane electrode assembly differs. For example, in case the membrane electrode assembly extends only a little bit over the bipolar plate, the membrane electrode assembly cannot vibrate extensively, so the resulting sound is sharp and short. On the other hand, in case the membrane electrode assembly is extending quite far over the bipolar plate, the membrane electrode assembly can vibrate “better”, but the vibration is dampened due to the long extension, which results in a long and low sound. Consequently, the sound generated by contacting the membrane electrode assembly cannot only be used for counting the number of membrane electrode assemblies but also for determining other features of the membrane electrode assembly, e.g., whether the membrane electrode assembly is correctly aligned in relation to the bipolar plate.

[0022] The membrane electrode assembly can be a 3-layer membrane electrode assembly comprising two electrodes being separated by a membrane. In this case, the membrane extends over the electrodes and can be used as electrical isolation. Further, a subgasket can frame the membrane electrode assembly forming a so called a 5-layer membrane electrode assembly. In this case the subgasket is extending over the bipolar plate and provides the electric isolation. Additionally, the membrane electrode assembly can comprise a gas diffusion layer sandwiching at the electrodes, resulting in 7-layer membrane electrode assembly. Thereby, the gas diffusion layer is arranged in the active area, namely in the area of the electrodes. Also in this case, the subgasket provides the electric isolation of adjacent bipolar plates.

[0023] For generating a sound, it is preferred to use the already protruding subgasket as part of the membrane electrode assembly which is contacted by the sound generating device. Besides the fact that the subgasket is easily contacted by the sound generating device due to its protrusion, it is also made from a plastic material which provides good vibration characteristics. Similar to a guitar string, it vibrates effectively when it comes into contact with a sound generating device, generating a distinctive sound. Alternatively, or additionally, the subgasket may also affect the membrane electrode assembly itself to generate a sound, indicating the presence of both the subgasket and the MEA.

[0024] According to a further preferred embodiment, the sound generated by contacting the unit fuel cell with the sound generating device generates a distinctive peak in the recorded sound file, wherein analysing the sound file includes identifying and analysing the at least one distinctive peak. These distinctive peaks vary depending on the arrangement of the membrane electrode assembly. For example, in case the membrane electrode assembly is correctly aligned, the distinctive sound peak shows a certain duration and pitch. In case the membrane electrode assembly is not correctly aligned, e.g., not extending sufficiently far or extending too far over the bipolar plate, the distinctive sound peak varies. In the first case, the sound peak would be higher and shorter, in latter case, the sound peak would be lower and longer compared with a sound peak generated by a correctly aligned membrane electrode assembly. Further, if the MEA does not extend over the bipolar plate, it may not be contacted by the sound generating device, resulting in no sound generation and no distinctive peak. Thus, analyzing the sound file by identifying and analysing the at least one distinctive peak, facilitates the determination of at least one feature of the fuel cell stack, such as the number of MEAs or the alignment of MEAs within the stack. Thereby, it is particularly preferred to analyse at least one distinctive peak based on its frequency, magnitude, and / or amplitude.

[0025] According to a further preferred embodiment, analysing the sound file include counting each distinctive peak and comparing the counted peaks with a predetermined reference number. As mentioned above, each distinctive peak indicates the presence of MEA in the stack. By simply counting the number of distinctive peaks and comparing them with the predetermined reference number, one or more missing membrane electrode assemblies can be easily and quickly determined. Additionally, the exact location(s) of the missing membrane electrode assembly(ies) can be determined, by simply counting the existing peaks, before or after a missed peak.

[0026] Thereby, it is further preferred to analyse the sound file by using a filter. The filter may provide an upper and / or lower threshold for the recorded sound file which the at least one distinctive peak has to meet in order to be counted. Particularly, the lower threshold allows for distinguishing actual peaks from background noise.

[0027] Further preferably, analysing the sound file includes determining a duration between adjacent peaks. The duration between adjacent peaks represents the time the sound generating device takes to move along the length of the fuel cell stack. If the MEA is missing or misaligned in a stack, the duration between adjacent peaks will increase.

[0028] According to a further preferred embodiment, generating the sounds includes guiding the sound generating device at a constant speed and / or a constant force along the fuel cell stack. Changes in the speed of guiding the sound generating device and / or of the force with which the sound generating device is contacting the stack can result in variations in sound generation, which can affect the accuracy of determining the features of the fuel cell stack. For example, even if the unit fuel cell is properly aligned, variations in the guiding speed and / or contact force may result in a sound which may indicate that the unit fuel cell is misaligned. Thus, by maintaining a constant speed / force while guiding the sound generating device, it is supposed that a consistent and continuous series of sound peaks can be produced. This allows for the accurate counting and determination of at least one feature of the fuel cell stack, particularly the number of fuel cell stack, without any errors caused by the device itself.

[0029] Consequently, as mentioned above, determining at least one feature of the fuel cell stack may be a misalignment, an alignment, a presence, and / or an absence of at least one unit fuel cell or part of the unit fuel cell, particularly of a membrane electrode assembly.

[0030] As mentioned above, a further aspect of the present invention relates to a system for performing a method for inspecting a fuel cell stack as described above.

[0031] The features and advantages described above in relation with the method also apply for the presented system.

[0032] The system for inspecting the fuel cell stack may be an integrated system comprising at least the sound generating device, the recording device, and the computing device and / or may comprise independent units, which may act independently and may be connected to each other through wired and / or wireless communication means. The recording device may be a microphone or any other sound / audio input device, which continuously records every generated sound by the sound generating device. Subsequently, the recording device stores the recorded sounds as a sound file featuring a plurality of distinctive peaks, e.g., in a storage device and / or in the computing device or may transmit the sound file to the computing device via wireless and / or wired means. The computing device then analyses the sound file to identify each distinctive peak to determine at least one feature of the fuel cell stack.

[0033] Further, the system may feature a user interface designed to facilitate user interaction, which can be in any form such as a graphical user interface, a display device, or any other user- controllable device facilitating interaction with the proposed system. This interface is designed to receive the analysed sound data results from the computing device and presents them to the user in a user-readable format. Furthermore, it can be configured to allow the users to perform actions or operations on both the displayed results and / or the system itself.

[0034] According to a further embodiment, the sound generating device is a hand-held device and / or an automatic device. Further, the sound generating device may be made of material comprising at least a thermoplastic polymer, preferably a polycarbonate.

[0035] According to a further preferred embodiment, the system for inspecting the fuel cell stack may be an automated system configured to autonomously guide the sound generating device along the length of the fuel cell stack at a contact speed / force and / or predetermined speed / force in such a way that the sound generating device generates a consistent sound by contacting the extending region of the stack. Subsequently, the system automatically captures the generated sounds using the recording device and stores the recorded sounds as a sound file in a storage device. Following this, the system automatically analyses the stored sound file using a computing device to identify and determine at least one characteristic of each distinctive peak to determine at least one feature of the fuel cell stack and displays the analysed results via the user interface to the users. The advantage of the proposed automation system is that it eliminates the errors that occur during the manual counting of fuel cell stacks and improves the accuracy of counting and quality of stacks. This ensures an operation of the sound generating device with constant force and constant speed.

[0036] Preferably the system further comprises an automatically operated unit, e.g. a linear rail unit and / or a robot, which is adapted to guide the sound generating device along the fuel cell stack at a constant speed and / or constant force. An even further aspect of the present invention relates to a method, a system or a computer program product comprising a computer program code which is adapted to prompt a control unit, e.g., a computer, and / or a computer of the above discussed control system to perform the above discussed steps or a computer program product for inspecting the fuel cell stack by employing machine learning system, including an artificial intelligence (Al).

[0037] Further preferred embodiments are defined in the dependent claims as well as in the description and the figures. Thereby, elements described or shown in combination with other elements may be present alone or in combination with other elements without departing from the scope of protection.

[0038] In the following, preferred embodiments of the invention are described in relation to the drawings, wherein the drawings are exemplarily only, and are not intended to limit the scope of protection. The scope of protection is defined by the accompanied claims, only.

[0039] The figures show:

[0040] Fig. 1 : a schematic view of a fuel cell stack,

[0041] Fig. 2: a schematic view of an inspection of the fuel cell stack according to an embodiment,

[0042] Fig. 3: a graphical representation of a sound file recorded at the fuel cell stack of Fig. 2,

[0043] Fig. 4: a schematic view of an inspection of the fuel cell stack according to a further embodiment,

[0044] Fig. 5: a graphical representation of a sound file recorded at the fuel cell stack of Fig. 4,

[0045] Fig. 6: a block diagram of a preferred embodiment of the system for inspecting the fuel cell stack, and

[0046] Fig. 7: a flow diagram of a preferred embodiment of the method for inspecting the fuel cell stack.

[0047] In the following same or similar functioning elements are indicated with the same reference numerals. Figs. 1, 2 and 4 illustrate a fuel cell stack assembly 1 comprising a plurality of unit fuel cells 12 arranged in a stacked configuration between two end plates 13 (only one is shown). Each unit fuel cell 12 comprises at least a bipolar plate 3 and at least a MEA 2. Each MEA 2 may extend over bipolar plates 3, creating a protruding region 4. Further, each MEA 2 is usually framed by a subgasket (not shown) which is protruding over the bipolar plate 3. Additionally, the MEA 2 may comprise a gas diffusion layer which is arranged between the bipolar plate 3 and the MEA 2. The gas diffusion layer may be attached to the MEA 2 itself.

[0048] During the stacking of the fuel cell stack 1 , parts of the unit fuel cell 12, e.g., bipolar plate 3 and MEA 2, or the unit fuel cell 12 as such, can be missed or misaligned. For example, as the MEA is typically a thin film structure, there's a risk of the MEA being improperly aligned or even missed entirely during the stacking process of individual unit fuel cells. This misalignment or absence of the MEA can lead to an incomplete unit fuel cell within the stack, resulting in the disruption of the fuel cell stack operation. Consequently, double-checking the alignment by counting the number of unit fuel cells becomes necessary to continue the operative performance of the fuel cell stack. However, manually counting fuel cell stacks over 455 unit cells with approximately 1mm cell pitch is challenging and time-consuming.

[0049] Therefore, the inventor has proposed to use the features of a sound file for counting the fuel cells instead of manually counting each unit fuel cell. Thereby, the sound file is created by contacting the unit fuel cells by means of the sound generating device 5 as is illustrated with reference to Figs. 3 and 5.

[0050] The sound generating device 5 may be a hand-held device, preferably a plectrum made of thermoplastic polymer such as a polycarbonate, which is adapted to contact any protruding regions of the unit fuel cells, as illustrated in Figs. 2 and 4, to generate a sound.

[0051] Since the membrane electrode assembly 2, and particularly the subgasket framing the membrane electrode assembly 2 is already protruding over the bipolar plate 3 for providing an electric isolation, and is made from a plastic material, the subgasket is the ideal part which should be contacted by the sound generating device 5. Upon contact, the subgasket vibrates and generates a distinctive sound based on its arrangement in relation to the bipolar plate 3. Thus, this distinctive sound can be used for analysing the features of the fuel cell stack 1 , e.g. counting the numbers of MEAs and / or determining whether the membrane electrode assembly corresponding to the subgasket is properly aligned. As shown in Fig. 2 and 4, the sound generating device 5 is guided from the initial position 5-1 in the direction 6 to a final position 5-2 (or vice versa) along the length of the fuel cell stack 1 at a consistent speed and with a constant force. Upon contacting the protruding regions 4 of MEA 2-1 to MEA 2-8, the sound generating device 5 generates a distinctive sound, which is recorded and stored in a sound file (see Fig. 3 and 5). As can be seen in Fig. 3 and 5, each contact with the membrane electrode assemblies 2-1 , 2-2, 2-3, 2-4, 2-5, 2-6 and 2-8 generates a corresponding distinctive peak 7-1 , 7-2, 7-3, 7-4, 7-5, 7-6 and 7-8 in the sound file.

[0052] As can be also seen in Fig. 2, membrane electrode assembly 2-7 is not extending over the bipolar plates 3-6 and 3-7. Consequently, the sound generating device cannot contact the membrane electrode assembly in this location, which results in the fact that there is no peak 7-7 in the sound file.

[0053] As can be seen in Fig. 4, membrane electrode assembly 2-7 is not extending far enough over the bipolar plates 3-6 and 3-7. Consequently, the sound generating device cannot properly contact the membrane electrode assembly in this location, which results in a peak 7 - 7 in the sound file, which is much lower than the rest of the peaks.

[0054] By analysing the sound file, the user can therefore draw conclusions on the features of the fuel cell stack, e.g. on a missing or misaligned membrane electrode assembly. Additionally, the user can get information on the location of the missing / misaligned membrane electrode assembly, by determining the number of peaks before and / or after the missed / deformed peak.

[0055] Besides the counting, the user can also get further information on the fuel cell stack by analysing e.g. frequency, amplitude, of each distinctive peak and / or a duration between adjacent distinctive peaks. For example, in case the membrane electrode assembly is not correctly aligned, e.g. not extending sufficiently far or extending too far over the bipolar plate, the distinctive sound peak varies in amplitude and frequency. In the first case, the sound peak would be higher and shorter, in latter case, the sound peak would be lower and longer compared with a sound peak generated by a correctly aligned membrane electrode assembly.

[0056] Thus, by simply analysing each distinctive sound peaks based on its characteristic such as frequency, amplitude, threshold peak, the numbers of MEAs present and aligned correctly in the stack can be easily determined and counted. As illustrated in Fig. 6, the process described above is carried out by a system 10 comprising a sound generating device 5, a recording device 9, a computing device 11, a storing device 14 and a user interface 15, in which the system 10 may be an integrated system or may operate as an independent unit connected to each other through wired and / or wireless communication means. Furthermore, system 10 may comprise the recording device 9 and the computing device 11 as a single integrated unit. Thereby, the system 10 may store and analyse the sound file using a single integrated unit. In addition, system 10 is implemented with a storing device 14 for storing the recorded sound file and a user interface 15 designed to receive the analysed sound data results from the computing device and presents them to the user in a user-readable format.

[0057] Further, Fig. 7 outlines the process described above in steps I to VI, which can be carried out sequentially or as discrete steps to inspect the fuel cell stack 1 using system 10. In step I, the sound generating device 5 is guided along the length of the fuel cell stack 1 to generate a distinctive sound for each contacted unit fuel cell 12. In step II, recording device 9 records and stores the distinctive sounds in a storing device 14 as a sound file comprising a collection of a plurality of distinctive peaks, and in step III, recording device 9 transmits the sound file to computing device 11 through wired and / or wireless communication means. Further, at step IV, computing device 11 analyses the sound file to determine at least one distinctive peak that indicates at least one feature of the fuel cell stack such as number of unit fuel cells, and at step V, computing device 11 outputs the analysed results via the user interface 15 to the users. Following this, in step VI, the user interface 15 allows the users to take further action on displayed results and the system 10 itself. Preferably the whole process is performed automatically, wherein an automatically controlled system is used. This ensures an operation of the sound generating device with constant force and constant speed.

[0058] In summary, the flexibility of the extended region of MEA or subgasket generates distinctive sound or vibration when struck by the sound generating device. Analyzing the sound file to determine the characteristics of these distinctive sounds allows for easy and precise counting of the number of unit fuel cells without the risk of miscounting errors. Additionally, it is possible to precisely locate the misaligned unit fuel cells within the stack.

[0059] Although a single embodiment of the invention has been illustrated in the accompanying drawings and described in the above detailed description, it will be understood that the invention is not limited to the embodiment developed herein, but is capable of numerous rearrangements, modifications, substitutions of parts and elements without departing from the spirit and scope of the invention.

[0060] Reference numerals

[0061] 1 Fuel cell stack

[0062] 2 Membrane electrode assembly (MEA)

[0063] 3 Bipolar plate

[0064] 4 Protruding region of MEA

[0065] 5 Sound generation device

[0066] 5-1 initial position

[0067] 5-2 final position

[0068] 6 Direction of guiding the sound generating device

[0069] 7 Distinctive sound peaks

[0070] 8 Duration between the adjacent peaks

[0071] 9 Recording Device

[0072] 10 System for inspecting fuel cell stack.

[0073] 11 Computing device

[0074] 12 Fuel cell unit

[0075] 13 End plate

[0076] 14 Storage Device

[0077] 15 User Interface

Claims

Method and system for inspecting a fuel cell stackClaims:

1. Method for inspecting a fuel cell stack, wherein the fuel cell stack comprises a plurality of unit fuel cells arranged in a stacked configuration, wherein each unit fuel cell comprises at least a membrane electrode assembly and at least a bipolar plate, characterized in that the method comprises the steps of: a. generating a sound by guiding a sound generating device along the fuel cell stack in such a way that the sound generating device contacts each unit fuel cells, b. recording the sounds generated by the sound generating device for creating a sound file, and c. analysing the sound file for determining at least one feature of the fuel cell stack.

2. Method according to claim 1, wherein analysing the sound file includes comparing at least one feature of the recorded sound file with a reference feature.

3. Method according to claim 1 or 2, wherein the sound generated by contacting the unit fuel cell with the sound generating device generates a distinctive peak in the recorded sound file, and wherein analysing the sound file includes identifying and analysing the at least one distinctive peak.

4. Method according to claim 3, wherein analysing the sound file includes counting the distinctive peaks and comparing the counted peaks with a predetermined reference number.

5. Method according to claim 3 or 4, wherein analysing the at least one distinctive peak comprises determining its frequency, magnitude and / or amplitude.

6. Method according to any one of claims 3 to 5, wherein analysing the sound file includes determining a duration between adjacent peaks.

7. Method according to any of the preceding claims, wherein generating the sound includes guiding the sound generating device at a constant speed and / or constant force along the fuel cell stack.

8. Method according to any of the preceding claims, wherein at least one membrane electrode assembly is adapted to extend at least partly beyond the bipolar plates, and wherein the sound generating device contacts the extend region of the at least one membrane electrode assembly for generating the sound.

9. System for performing a method for inspecting a fuel cell stack according to any one of claims 1 to 8, wherein the fuel cell stack comprises a plurality of unit fuel cells arranged in a stacked configuration, wherein each unit fuel cell comprises at least a membrane electrode assembly and at least a bipolar plate, characterized in that the system comprises: a. a sound generating device which is configured to generate a sound when guided along the fuel cell stack, such that the sound generating device contacts the unit fuel cells, b. a recording device which is configured to record the sounds generated by the sound generating device for creating a sound file, and c. a computing device which is configured to analyse the sound file for determining at least a feature of the fuel cell stack.

10. System according to claim 9, wherein the system further comprises a storing device for storing the recoded sound file.

11. System according to claim 9 or 10, wherein the system further comprises a user interface, particularly a display device, and the computing device is further configured to output a result of the analysis of sound file to the user interface.

12. System according to any one of claims 9 to 11 , the sound generating device is made of a material comprising at least a thermoplastic polymer, preferably a polycarbonate.

13. System according to any one of claims 9 to 12, wherein the sound generating device is a hand-held device and / or automatic device.

14. System according to any one of claims 9 to 13, wherein the sound generating device is in wireless and / or in wired communication with the recording device, and / or wherein the recording device is in wireless and / or in wired communication with the computing device.

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