Installation Method of Acoustic Leak Detection System

Abstract

The present invention relates to a method of installing an acoustic leak detection system in a fluid distribution network, the method being characterized by the steps of: disposing at least one first acoustic sensor (10) in the fluid distribution network; disposing at least one acoustic signal generator (26) in the fluid distribution network at a location along the piping (4) away from the at least one first acoustic sensor (10); generating an acoustic signal by the acoustic signal generator (26); evaluating whether the generated acoustic signal is detected by the at least one first acoustic sensor (10); and, if the generated acoustic signal is not detected by the at least one first acoustic sensor (10), disposing at least one second acoustic sensor (24) at a location in the fluid distribution network less far along the piping (4) from the location of the acoustic signal generator (26) than the at least one first acoustic sensor (10).

Description

Technical Field

[0001] The present invention relates to a method of installing an acoustic leak detection system in a fluid distribution network, particularly a liquid distribution network.

Background Art

[0002] It is known to arrange acoustic sensors in a liquid distribution network as an acoustic leak detection system. In particular, it is known to arrange acoustic sensors in the main distribution pipes of a liquid distribution network in order to detect leaks in the pipes of the liquid distribution network based on the noise generated. When installing acoustic sensors, it is preferably an issue to optimize the position of the sensors so that the entire distribution network can be monitored and to minimize the number of acoustic sensors required.

Summary of the Invention

Problems to be Solved by the Invention

[0003] An object of the present invention is to provide a method of installing an acoustic leak detection system in a fluid distribution network, particularly a liquid distribution network, whereby on the one hand it is possible to minimize the number of sensors required and on the other hand it is possible to reliably monitor the entire distribution network and detect the possibility of leaks.

Means for Solving the Problems

[0004] This object is achieved by a method having the features described in claim 1. Preferred embodiments are specified in the dependent claims, the following description, and the accompanying drawings.

[0005] The method according to the invention is used to install an acoustic leak detection system in a fluid distribution network, in particular a liquid distribution network such as a water distribution network or a heat distribution network. The distribution network is composed of a plurality of pipes for distributing fluid or liquid. Preferably, the distribution network includes a main distribution pipe, branch distribution pipes, and branch pipes (also called branch tubes) connecting to a single consumption point such as a detached house.

[0006] According to this method, at least one first acoustic sensor is arranged in the distribution network. The acoustic sensor is, in particular, an acoustic sensor suitable for acoustic leak detection and is provided to detect the noise generated by the leak. In particular, such a sensor can detect the noise in the frequency range to which the noise generated by the leak is expected to belong. Such a first acoustic sensor is preferably directly attached to the pipes of the distribution network or to components or devices connected to the pipes, or can be incorporated into such components or devices. Thus, preferably, at least one first acoustic sensor is in contact with the pipe so that the noise transmitted through the wall of the pipe and / or the noise transmitted inside the liquid flowing through the pipe can be detected by at least one first acoustic sensor.

[0007] Furthermore, at least one acoustic signal generator is arranged at a position remote from at least one first acoustic sensor in the distribution network, i.e., at a position remote along the length of the pipe. The signal generator is arranged in the pipe such that the acoustic signal generated by the signal generator is transmitted through the liquid in the pipe and the distribution network. In the next step, an acoustic signal is generated by the acoustic signal generator, and the acoustic signal is within a frequency range detectable by the at least one first acoustic sensor, i.e., preferably within a frequency range characteristic of the leak to be detected. The acoustic signal generator preferably includes an electrical signal oscillator having an amplifier and a loudspeaker. In the next step, it is evaluated whether the at least one first acoustic sensor detects such a generated acoustic signal, i.e., the acoustic signal generated by the acoustic signal generator. If the above-described acoustic signal from the acoustic signal generator cannot be detected by the at least one first acoustic sensor, this indicates that the acoustic signal generator is arranged too far away from the first acoustic sensor when measured along the pipe of the distribution network. Therefore, leaks occurring in the area where the acoustic signal generator is arranged are not detected by the at least one first acoustic sensor. Thus, according to the present invention, at least one second acoustic sensor is arranged in the distribution network at a position between at least one first acoustic sensor that does not receive the acoustic signal and the acoustic signal generator when measured along the length of the pipe of the distribution network. The at least one second acoustic sensor is arranged not to be too far away from the position of the acoustic signal generator. This means that when viewed along the pipe of the distribution network, the at least one second acoustic sensor is arranged closer to the acoustic signal generator than the first acoustic sensor. By arranging the at least one second acoustic sensor at the above-described position in the distribution network, acoustic dead spots in the distribution network are reduced or avoided. This is because any sound generated from a leak at any position in the distribution network is guaranteed to be detected by at least one acoustic sensor, i.e., either by the at least one first acoustic sensor and / or by the at least one second acoustic sensor.The acoustic sensor can be connected to a leak detection system or a leak evaluation system known in the art to identify the location of leaks in the distribution network based on the sound or noise detected by one or more sensors arranged in the distribution network. Such a leak detection system or leak evaluation system is preferably implemented as software within the head-end system (HES) of a water supply facility.

[0008] When the acoustic signal generated by the acoustic signal generator is detected by at least one first acoustic sensor arranged in the distribution network, it is not necessary to arrange the second acoustic sensor in an area close to the location of the acoustic signal generator or the acoustic signal machine. In this case, the sound generated from the leak in the area where the acoustic generator is arranged can be detected by at least one first acoustic sensor. Therefore, it is not necessary to arrange the second acoustic sensor in this area or between the location of the acoustic generator and the first acoustic sensor. By this method, it is possible to reduce the number of required acoustic sensors.

[0009] According to certain embodiments of the present method, at least one second acoustic sensor is disposed in the distribution network before an acoustic signal is generated by an acoustic signal generator. If the acoustic signal is not detected by at least one first acoustic sensor or at least one second acoustic sensor, at least one additional second acoustic sensor is disposed at a location in the distribution network where the distance along the pipe from the location of the acoustic signal generator is shorter than the distance to at least one first acoustic sensor disposed in the distribution network and the distance to said at least one second acoustic sensor. This means that, when viewed along the extent of the pipe of the distribution network, at least one additional second acoustic sensor is disposed near the location of the other acoustic sensors. By this embodiment of the method, it can be ensured that noise generated from leaks within the system is detected by the first acoustic sensor or the second acoustic sensor within the distribution network. Both the first acoustic sensors and the second acoustic sensors already disposed in the distribution network can be used to find remaining dead spots that can be removed by the placement of additional acoustic sensors. That is, it is evaluated whether an acoustic signal from the acoustic signal generator is received by a first acoustic sensor or a second acoustic sensor already disposed in the distribution network.

[0010] Preferably, the amplitude of the acoustic signal received by at least one first acoustic sensor and / or at least one second acoustic sensor is evaluated to determine the optimal position of a further second acoustic sensor within the distribution network. In order to ensure reliable leak detection, it is necessary for the sensor to detect, for example, at least a minimum amplitude. Preferably, the at least one second acoustic sensor or the further second acoustic sensor is located along the pipe at a position where the amplitude of the acoustic signal output by a signal generator arranged at the same position and received by at least one first acoustic sensor exceeds a preset minimum value, preferably at a position where it reaches or approaches a maximum value. For example, the signal generator can be arranged at various positions, and the amplitudes of the acoustic signals received by different sensors are compared for the various positions of the signal generator. Then, in the next step, a further second acoustic sensor can be arranged at the optimal position. The optimal position is, for example, the position of the signal generator where one or more sensors detect a signal exceeding a preset minimum value, more preferably, a maximum amplitude or an amplitude close to the maximum amplitude. Preferably, at least a preset minimum amplitude needs to be detected by the sensor in order to reliably detect leaks at each position.

[0011] At least one first acoustic sensor and / or an acoustic signal generator may be incorporated into a flow meter, or at least one ultrasonic flow meter within a fluid distribution network may be used as the first acoustic sensor and / or as the acoustic generator, and the flow meter is preferably arranged within a branch pipe of the fluid distribution network. This may in particular be a branch pipe connecting to a consumption point such as a single-family house. According to this embodiment of the method, a flow meter arranged in the distribution network for detecting and measuring fluid consumption may further be used for leak detection. For this purpose, additional detection elements for noise detection may be incorporated into the flow meter and / or the ultrasonic sensors used for flow detection may also be used for noise detection. The branch pipes in the fluid distribution network may be plastic pipes, and the first acoustic sensors may be optimized to detect noise conducted through these branch pipes, in particular plastic branch pipes.

[0012] According to a preferred embodiment for leak detection, in addition to a second acoustic sensor arranged separately in the fluid distribution network, the above-mentioned sensors within the flow meter are used. In a fluid distribution network, all flow meters arranged within the distribution network may be used for noise detection, i.e., as the first acoustic sensors. Alternatively, such a noise detection function may be provided only for a specific number of flow meters, and it is also possible to use these flow meters as the first acoustic sensors described above.

[0013] At least one second acoustic sensor is preferably an acoustic sensor independent of the flow meter and preferably has a microphone or an accelerometer. In particular, the second acoustic sensor may be an independent device provided only for noise detection, a so-called data logger. Preferably, such at least one second acoustic sensor is arranged on the wall of the distribution pipe of the distribution network, in particular on the wall of the main distribution pipe of the distribution network, or inserted into the fluid through the wall. In the latter case, a hydrophone (water pipe leak detector) can be used. Such a distribution pipe can be made of metal, for example. The distribution pipe may be a pipe that further branches therefrom. At least one second acoustic sensor is preferably connected to the pipe at a position where a further device such as a valve is arranged on the pipe. This makes it possible to use existing access points to arrange at least one second acoustic sensor on the pipes of the distribution network.

[0014] At least one first acoustic sensor and at least one second acoustic sensor are preferably connected to an analysis system or an evaluation system via a wireless signal connection. The evaluation system may include a central computing device that performs the described evaluation. The evaluation system may further include a mobile device or a handheld device that enables control by an operator on site. Such a mobile device may be connected to a central evaluation device or a central computing device. Alternatively, the mobile device may communicate directly with the acoustic sensor and perform the evaluation directly.

[0015] Preferably, the evaluation system includes a mobile device that visualizes the evaluation results, especially on a display. Such a mobile device can be used by an operator on site. Preferably, the visualization on the display shows the entire distribution network, for example, in the form of a map showing the positions of all sensors and acoustic signal generators within the distribution network. Such visualization helps the operator find the optimal positions to place the second acoustic sensors within the system to avoid dead spots and at the same time helps minimize the number of second acoustic sensors required.

[0016] In one solution, at least one acoustic signal generator can be connected to and controlled by an evaluation system, in particular a central evaluation system. Such a connection enables the evaluation system to start the acoustic signal generator or the output of the acoustic signal by the acoustic generator, respectively. Further, the evaluation system or evaluation device can directly receive feedback from one or more first acoustic sensors and / or second acoustic sensors already arranged in the system to evaluate which sensors can receive the acoustic signal output by the acoustic signal generator. The result is then presented to the operator on a display and / or an automatic evaluation can be performed to indicate at which points in the distribution network additional acoustic sensors, in particular second acoustic sensors, should be arranged to enable the detection of acoustic leaks throughout the distribution network. According to this embodiment, this means that at least one acoustic signal generator and an acoustic sensor, in particular a first acoustic sensor arranged in the system, can be synchronized by the central evaluation system or evaluation device. However, in another solution, it is possible to avoid such synchronization. In embodiments using an asynchronous acoustic signal generator, the signal generator or acoustic generator can be installed and activated by either the evaluation system or the operator. Thereafter, the signal generator can be left to generate an acoustic signal or sound for a longer period, for example one day or several days, for example up to ten days at most.

[0017] According to a further embodiment, at least one acoustic signal generator may generate an acoustic signal that identifies or characterizes itself (the acoustic signal generator), i.e., an acoustic signal that is specific to the acoustic signal generator. For example, the signal generator may generate a predetermined sound pattern that is specific to the signal generator and can be identified by an acoustic sensor and / or an evaluation device or a control device that evaluates the signal from the acoustic sensor. For example, the sound pattern may be composed of an alternating sound generation phase and a silent phase. As an example, it may be a sound generation phase having a predetermined duration followed by a predetermined silent phase. For example, the acoustic generator may generate noise for 6 hours, then be silent for 3 hours, and then generate noise again for 6 hours. Such a sound pattern can be detected by an acoustic sensor without the need for synchronization with the signal generator. The sound pattern is selected so that it can be clearly distinguished from normal noise in the system, i.e., it can be identified by an appropriate evaluation system. The detection or identification of the pattern can be performed directly in the acoustic sensor, preferably a flow meter functioning as an acoustic sensor. Alternatively, or in addition, the sound pattern or characteristics of the acoustic signal generated by the acoustic generator may be detected by an external evaluation system, particularly a central evaluation system. The acoustic signal received by the acoustic sensor, particularly the flow meter, or the signal representing the acoustic signal can each be transferred, for example, to an evaluation device, and the detection of the signal specific to the acoustic generator can be performed by the evaluation device. That is, each analysis can be performed in the head-end system. According to this method, since synchronization between the sensor and the signal generator is not required, the system can be simplified.

[0018] If the analysis or evaluation indicates that a further second acoustic sensor needs to be placed in the distribution network, preferably at least one second acoustic sensor is placed along the piping of the distribution network at a predetermined or calculated distance from the location of the acoustic signal generator used in this evaluation step. More preferably, at least one second acoustic sensor is placed along the piping between the signal generator and the location of an acoustic sensor, particularly a first acoustic sensor that was unable to receive the signal generated by the acoustic signal generator.

[0019] After the above analysis of the distribution network for placing the necessary acoustic sensors, preferably the acoustic signal generator is removed from the fluid distribution network. Thus, it is preferred to use a removable acoustic signal generator. If the acoustic signal generator is incorporated into another component used in the distribution network, for example, a flow meter, the signal generator may remain in the distribution network. If the signal generator is removed, the removed signal generator may be used at different locations in the distribution network or in another distribution network to evaluate the need for further acoustic sensors for leak detection.

[0020] The acoustic signal generator preferably generates an acoustic signal in a frequency range detectable by at least one first acoustic sensor and at least one second acoustic sensor, and more preferably generates a signal in a frequency range used for acoustic leak detection. Thus, to evaluate the need for further acoustic sensors, an acoustic signal in the frequency range of the noise that must be detected for leak detection is used. Preferably, the signal amplitude is also selected to correspond to the amplitude of the leak noise.

[0021] The acoustic signal generator may generate a white noise signal and / or a signal in the frequency range between 10 Hz and 2 kHz. This is a preferred frequency band. However, the present invention is not limited to this frequency band. The generated signal may be a single frequency signal, for example, a 1 kHz signal. However, such a narrowband signal may be lost due to unexpected resonance, coupling phenomenon, or acoustic attenuation by the pipe wall. In particular, plastic pipes have a large attenuation. Therefore, the generated signal should preferably include a plurality of frequency components selected in the frequency range between 10 Hz and 2 kHz.

[0022] At least one acoustic signal generator may continuously output an acoustic signal. However, according to an embodiment, the acoustic signal is generated by the signal generator for a predetermined time, for example, from 30 seconds to 1 minute. The interruption of the signal output by the signal generator may respectively improve the analysis or signal detection by the acoustic sensor and / or the connected evaluation device.

[0023] At least one first acoustic sensor, at least one second acoustic sensor, and / or at least one acoustic signal generator may be battery-powered. This eliminates the need for an external power source, thus simplifying the installation into the distribution network. In particular, when a flow meter or a flow consumption meter is used as the acoustic sensor, it is preferable that these flow meters are battery-powered. On the other hand, in this case, it is necessary to optimize the method in consideration of the power consumption. This method should preferably be implemented with minimal power consumption so that the lifespan of the flow meter is not shortened by the lifespan of the battery. As described above, in the specific case where a flow meter or an ultrasonic flow meter also functions as an acoustic signal generator, for example, when a loudspeaker is incorporated, the battery needs to be larger than that used in a normal flow meter, for example, a large D-cell lithium battery. Preferably, in the distribution network, it is estimated that one large battery signal generating flow meter per 10 to 50 households is sufficient.

[0024] According to a further preferred option, during the evaluation or analysis of the need for additional acoustic sensors, for other reasons, namely, to reduce or avoid changes in the noise generated in the system or distribution network by additional aggregates in the system, it is preferable to bring the water distribution network to a stable state. For example, noise may be generated from pumps or valves within the system. In this case, it is preferable to place such pumps or valves in a stable state. Further, additionally or alternatively, the noise sources within the distribution network may be in an operating state that generates maximum noise. For example, when the pump is in a full load mode where high flow noise and / or pump noise is generated. Analyzing the system for the need for additional acoustic sensors at the maximum noise level can ensure that leak detection is possible even at high noise levels. If the acoustic sensor can detect the acoustic signal generated from the acoustic signal generator when the noise level is high, it becomes possible to detect noise even at relatively low flow levels.

[0025] According to a preferred embodiment of the present invention, a flow meter configured to function as an acoustic sensor is arranged in the distribution network. It is possible to provide all the flow meters within the system with the function of detecting acoustic noise. Alternatively, the flow meters for acoustic leak detection are arranged only at important points in the system. By using such special flow meters, it is possible to avoid or reduce the number of additional second acoustic sensors in the distribution network. Preferably, these flow meters are mainly used for leak detection in a fluid distribution network or a liquid distribution network. Therefore, preferably, first, a flow meter having acoustic leak detection characteristics is arranged in the distribution network, and then the above method is executed to evaluate at which further positions additional second acoustic sensors are required to cover the entire distribution network for acoustic leak detection. By this method, the number of additional second acoustic sensors required can be minimized, and flow meters having acoustic leak detection characteristics can be used as much as possible instead of special sensors.

Brief Description of the Drawings

[0026]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0027] Hereinafter, the present invention will be described by way of examples with reference to the accompanying drawings. FIG. 1 shows an example of a water distribution network for distributing water to various consumption points (here, house 2). House 2 is connected via a branch pipe or a lateral pipe 4 that leads to the main distribution pipe 6. The water in the main distribution pipe 6, and thus the water in the water distribution network, is sent by a pumping device 8. At each consumption point, that is, at each house 2, a flow meter 10 is provided to measure the water consumption. The flow meter 10 may be an ultrasonic flow meter that detects the flow rate by an ultrasonic sensor. The flow meter 10 is equipped with wireless communication. That is, the flow meter 10 includes a wireless communication module 12. The wireless communication module 12 connects the flow meter 10 to a control device or an evaluation device 16, that is, a head-end system, via a communication network 14. Further, the flow meter may include, for example, a near-field communication technology (NFC) for communicating with a handheld device. In some embodiments, the flow meter 10 may be capable of two-way communication.

[0028] The flow meter 10 includes a flow sensor, in this example an ultrasonic flow sensor 18 within a housing 20. Additionally or alternatively, the housing 20 may include a separate noise sensor or acoustic sensor 22. By using the ultrasonic sensor 18 or the acoustic sensor 22, the flow meter 10 can function as a first acoustic sensor for detecting acoustic noise within the branch pipe 4. The detected noise or a signal derived from the detected noise is sent via a wireless communication module 12 to a control device or evaluation device 16. This is preferably the same wireless communication link used to send the metering result, i.e., the metered water consumption, to the central control device 16. The noise detection function within the flow meter 10 can be optimized to detect noise transmitted by the branch pipe 4, which is often a thin pipe made of plastic material. The flow meter 10 functioning as a first acoustic sensor enables listening within the water distribution network and detecting leaks within the distribution network, i.e., outside the house 2, based on the noise generated. Thus, the flow meter 10 having a noise detection function can be used instead of a separate acoustic sensor for leak detection in the distribution network, i.e., it is possible to reduce the required number of separate acoustic sensors for leak detection. Ideally, for leak detection, the entire fluid distribution network could be covered by these first acoustic sensors in the form of the flow meter 10. However, typically, in a large-scale and complex fluid distribution network, it is not possible to cover the entire network. That is, dead spots or areas remain where noise cannot be detected by the flow meter 10 located at the end of the branch pipe 4, i.e., at the consumption point within the house 2.

[0029] In these areas, a further acoustic sensor, namely the second acoustic sensor 24, is arranged. These second acoustic sensors 24 are configured for the sole purpose of noise detection and may include, for example, microphones. In this example, the second acoustic sensor 24 is arranged at point A. The second acoustic sensor 24 is provided with a wireless communication module and is connectable to the communication network 14 and the control or evaluation device 16. Thus, the noise signal detected by the second acoustic sensor 24, more precisely the acoustic signal, or the information obtained from these signals, is sent to the control or evaluation device 16 and used for leak detection within the distribution network. These second acoustic sensors 24 are used in relation to the noise detection characteristics of the flow meter 10 in order to identify the location of leaks inside the distribution network by means of noise detection. Characteristic acoustic signals generated based on the leak are sent or guided through the pipes to the sensors 10, 24 and detected by the first acoustic sensor (flow meter 10) and the second acoustic sensor 24. By considering which sensor receives or listens to the respective noise characteristics regarding the leak, it is possible to identify the location of the leak.

[0030] An acoustic signal generator 26 is used to find a position where the second acoustic sensor 24 should be placed so that there are no dead zones in the distribution network. The acoustic signal generator 26 is placed, for example, by the operator 24, at a position that may be important for leak detection in the operator's view. Preferably, the acoustic signal generator 26 is placed on the pipe, at an accessible position of the main distribution pipe 6 in this example, for example, at the position of a valve in the distribution network. In this example, the acoustic signal generator 26 is placed at point D. The acoustic signal generator 26 outputs an acoustic signal in a frequency range considered for acoustic leak detection. Then, the operator 28 analyzes which first acoustic sensor, i.e., which flow meter 10, detects the acoustic signal output by the acoustic signal generator 26. The operator 28 in this example uses a software application on a handheld device 30, for example, a smartphone. The handheld device 30 has a wireless communication module and is capable of direct wireless communication with the communication module 12 of the flow meter 10, the acoustic signal generator 26, and / or wireless communication with a sensor control device or evaluation device 16 via the communication network 14. The operator 28 can directly initiate the output of the acoustic signal by the acoustic signal generator 26 by direct communication with the acoustic signal generator 26 or via the control device 16. In this case, the acoustic signal generator 26 may include a communication module that enables communication with the central control device 16.

[0031] If the acoustic signal generated by the acoustic signal generator 26 is receivable by at least one of the flow meters 10, there is no need to place a further second acoustic sensor 24 at point D. However, if neither the flow meters 10 already arranged in the distribution network nor the second acoustic sensor 24 can detect the acoustic signal output by the acoustic signal generator 26, the operator 28 can decide to place a further second acoustic sensor 24 at point D. This method can be carried out for further points in the distribution network, for example, point B or point C shown in FIG. 1.

[0032] The handheld device 30 includes a display 32, which can visualize the entire distribution network for the operator 28, and in particular can display all acoustic sensors, namely the flow meter 10 functioning as the first acoustic sensor and the second acoustic sensor 24. The display 32 can directly visualize which sensor 10 receives the acoustic signal generated by the acoustic signal generator 26.

[0033] Instead of the manual evaluation as described above, the software application in the handheld device 30 and / or the central evaluation device 16 may evaluate where the second acoustic sensor 24 should be placed. The central control device 16 may inform the operator 28, for example, via the handheld device 30, where the acoustic signal generator 26 should be placed for the evaluation process.

[0034] To further improve the detection of acoustic leakage during evaluation, whether an additional second acoustic sensor 24 is required, and where an additional second acoustic sensor 24 is required, preferably the pump device 8 and possibly further devices are set to the operating state that generates the maximum noise in the distribution network. This ensures that acoustic leakage detection is reliably performed even in such an operating state.

[0035] The above method enables leakage detection throughout the distribution network mainly by using the flow meter 10 having a leakage detection module. In positions or areas in the distribution network where the flow meter 10 cannot listen, i.e., additional second acoustic sensors 24 can be arranged as needed. Therefore, the number of necessary second acoustic sensors 24 can be minimized, and the essential elements of acoustic leakage detection can be provided by the flow meter 10 required at the consumption point.

Explanation of Signs

[0036] 2 House, consumption point 4 Branch pipe 6 Main distribution pipe 8 Pump device 10 Flow meter, first acoustic sensor 12 Wireless communication module 14 Communication network 16 Control device or evaluation device 18 Flow sensor 20 Housing 22 Acoustic sensor 24 Second acoustic sensor 26 Acoustic signal generator 28 Operator 30 Handheld device 32 Display Positions within the fluid distribution network A, B, C, D

Claims

1. A method of installing an acoustic leak detection system in a fluid distribution network, comprising: placing at least one first acoustic sensor (10) in the fluid distribution network; placing at least one acoustic signal generator (26) at a position along the pipe (4) away from the at least one first acoustic sensor (10) in the fluid distribution network; generating an acoustic signal by the acoustic signal generator (26); evaluating whether the generated acoustic signal is detected by the at least one first acoustic sensor (10); if the generated acoustic signal is not detected by the at least one first acoustic sensor (10), placing at least one second acoustic sensor (24) at a position in the fluid distribution network where the distance measured along the length of the pipe (4) from the position of the acoustic signal generator (26) is shorter than the distance from the at least one first acoustic sensor (10) to the acoustic signal generator (26); including wherein the at least one first acoustic sensor (10) is incorporated in a flow meter and the at least one second acoustic sensor (24) is an acoustic sensor independent of the flow meter. A method characterized by the above.

2. The method according to claim 1, characterized in that when the generated acoustic signal is detected by the at least one first acoustic sensor (10), the second acoustic sensor (24) is not arranged at the position of the acoustic signal generator (26).

3. placing at least one second acoustic sensor (24) in the fluid distribution network before generating an acoustic signal by the acoustic signal generator (26), If the generated acoustic signal is not detected by the at least one first acoustic sensor (10) or the at least one second acoustic sensor (24), at least one additional second acoustic sensor (24) is placed at a position in the fluid distribution network where the distance along the pipe (4) from the position of the acoustic signal generator (26) is shorter than that of the at least one first acoustic sensor (10) and the at least one second acoustic sensor (24) previously arranged in the fluid distribution network. The method according to claim 1 or 2, characterized in that.

4. The at least one second acoustic sensor (24) or the at least one additional second acoustic sensor (24) is arranged at a position along the pipe where the amplitude of the acoustic signal generated by an acoustic signal generator (26) arranged at the same position and received by the at least one first acoustic sensor (10) exceeds a predetermined minimum value. The method according to any one of claims 1 to 3.

5. The acoustic signal generator (26) is incorporated in a flow meter, or at least one ultrasonic flow meter in the fluid distribution network is used as the first acoustic sensor (10) and / or as the acoustic signal generator (26), and the flow meter or the ultrasonic flow meter is arranged in the branch pipe (4) of the fluid distribution network. The method according to any one of claims 1 to 4.

6. The at least one second acoustic sensor (24) has a microphone and / or an accelerometer. The method according to any one of claims 1 to 5.

7. The at least one second acoustic sensor (24) is arranged in the distribution pipe (6) of the fluid distribution network, and the distribution pipe (6) is made of metal. The method according to any one of claims 1 to 6.

8. The method according to any one of claims 1 to 7, characterized in that the at least one first acoustic sensor (10) and the at least one second acoustic sensor (24) are connected to an evaluation system (16) via a wireless signal connection (14).

9. The method according to any one of claims 8, characterized in that the evaluation system includes a mobile device (30) for visualizing the evaluation result.

10. The method according to any one of claims 1 to 9, characterized in that the at least one acoustic signal generator (26) is connected to an evaluation system (16) and is controlled by the evaluation system (16).

11. The method according to any one of claims 1 to 10, characterized in that the at least one acoustic signal generator (26) generates an acoustic signal for identifying the at least one acoustic signal generator (26) by a predetermined sound pattern.

12. The method according to any one of claims 1 to 11, characterized in that the at least one acoustic signal generator (26) is removed from the fluid distribution network after evaluating the need to place the second acoustic sensor (24).

13. The method according to any one of claims 1 to 12, characterized in that the at least one acoustic signal generator (26) generates an acoustic signal in a frequency range detectable by the at least one first acoustic sensor (10) and the at least one second acoustic sensor (24).

14. The method according to any one of claims 1 to 13, characterized in that the at least one acoustic signal generator (26) generates a white noise signal and / or a signal in a frequency range from 10 Hz to 2 kHz.

15. The method according to any one of claims 1 to 14, characterized in that the acoustic signal is generated by the at least one acoustic signal generator (26) for 30 seconds to 1 minute.

16. The method according to any one of claims 1 to 15, characterized in that the at least one first acoustic sensor (10), the at least one second acoustic sensor (24), and / or the at least one acoustic signal generator (26) are battery-powered.

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