KR101656858B1 - Acoustic Emission sensor apparatus and wireless defect diagnostics system for high pressure pipe using thereof - Google Patents

Abstract

The present invention relates to an acoustic emission signal sensor device capable of stably fixing to a curved surface high pressure pipe, and a wireless fault diagnosis system for a high pressure pipe which wirelessly diagnoses defect, defect degree, and defect position of a high pressure pipe using the acoustic emission signal sensor device.

More particularly, the present invention relates to an AE sensor having a first connector on one side and a substantially cylindrical bottom surface which is in close contact with a high-pressure pipe as a magnetic body of a curved surface, Wherein the AE sensor is housed in the bottom surface of the at least one magnet to expose the bottom surface and the second connector is coupled to the first connector at one side of the inner surface of the inlet, housing; An elastic means inserted into the bow inlet and exerting elasticity such that the AE sensor moves away from the housing; And a signal processing module that is electrically connected to the second connector and is embedded in the housing and that processes and transmits an acoustic emission signal sensed by the AE sensor. The present invention also provides an acoustic emission signal sensor device using the same, And a central signal processing unit for receiving the signal transmitted from the signal processing module and calculating a defect, defect degree, and defect position of the high-pressure pipe, and a central signal processing unit for diagnosing the wireless defect of the high-pressure pipe.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an acoustic emission signal sensor device and a wireless fault diagnosis system for a high-

The present invention relates to an acoustic emission signal sensor device and a wireless fault diagnosis system for a high-pressure pipe using the same. More particularly, the present invention relates to an acoustic emission signal sensor device capable of stably fixing to a curved surface high pressure pipe, and a wireless fault diagnosis system for a high pressure pipe that wirelessly diagnoses whether a high pressure pipe is defective, defective or defective.

With the rapid industrialization and urbanization all over the world, the need for a high-output industry based on the efficient distribution of energy is heightening, and in parallel with this, the construction of large-scale industrial facilities for the production of large quantities of energy such as boilers and generators has increased greatly . However, some of them are worried about the stability of industrial facilities. If defects are found in the internal structures of industrial facilities concealed from the outside, it is very difficult to find them.

Accordingly, efforts have been made to detect early defects such as micro-deformation, micro-cracking, etc. of internal structures for industrial facilities. However, there is no practical advantage in diagnosing defects in the past that add additional anthropogenic damage.

Therefore, 'non-destructive inspection', which can diagnose defects without damaging the object, is attracting attention.

'Non-destructive testing' is a method to investigate and judge incompleteness without using any additional damage by using the physical phenomenon of the material, and there are various methods such as radiation penetration method, ultrasonic flaw detection method, magnetic flaw detection method, And so on. However, most non-destructive testing methods are difficult to apply to internal structures of industrial facilities with limited accessibility because they are directly and once energy applied to the object to check for defects.

Meanwhile, a non-destructive testing method using an acoustic emission (AE), which has been recently known, uses an acoustic emission signal (AE) of a specific frequency band among elastic waves accompanied by deformation or cracking of an object, . Therefore, it can be applied to the case where the access is restricted because the object is not sensitive to the structure, defect size, and direction of the object, although it corresponds to the nondestructive inspection method of the ultrasonic wave region in a strict sense.

However, since the acoustic emission signal contains various noise ranging from the low frequency band, which is the audio frequency, to the high frequency band of several MHz, it is difficult to accurately analyze and the result is largely changed depending on the sensitivity of the sensor. Therefore, at present, only the acoustic emission signal of a specific frequency band accompanied by the leakage of the object water is used, but leakage is a phenomenon appearing after the cracking, so it is eventually followed by post management.

In addition, the conventional nondestructive testing method using an acoustic emission signal judges leakage through an alarm or an alarm for a measurement value exceeding a reference value, for example, a measurement value exceeding an upper limit value of a reference dB. Therefore, it is difficult to obtain precise information, so if the leakage is detected, it is necessary to stop the industrial facility. Therefore, it causes considerable economic loss until the completion of maintenance after the stoppage of the facility.

In addition, a conventional sensor for detecting an acoustic emission signal, such as an acoustic emission signal sensor (hereinafter referred to as an AE sensor), has a cylindrical shape in which the number and position of the connector for cable connection are somewhat changed , And a substantially flat bottom surface is brought into close contact with the object surface.

Therefore, it is difficult to fix on a curved surface such as a high-pressure pipe.

In addition, since a large number of AE sensors are used for defect inspection of industrial facilities, and in particular, a large number of AE sensors are used for inspection of large facilities such as high-pressure piping, the operator fixes each AE sensor on the curved high- The entire work process is very troublesome and time and cost are consumed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a concrete method for relatively easily and accurately detecting whether or not a defect in an internal structure of a large industrial facility with limited access is solved.

Specifically, the present invention provides an AE sensor device that can be easily fixed to a flat surface such as a high-pressure pipe as well as a flat surface, thereby being excellent in workability and capable of wireless communication and greatly reducing time and effort for cable connection. Put the purpose.

Further, the present invention efficiently removes and analyzes unnecessary noise from low-frequency and high-frequency signals collected in the field to improve the reliability of signal analysis, and wirelessly diagnoses whether the high-pressure pipe is defective, The present invention is directed to a radio-coupled diagnostic system that can be used in a wireless communication system.

According to an aspect of the present invention, there is provided an AE sensor comprising: a first connector having a first connector and a substantially cylindrical bottom surface which is closely attached to a high-pressure pipe as a magnetic body of a curved surface; Wherein the AE sensor is housed in the bottom surface of the at least one magnet to expose the bottom surface and the second connector is coupled to the first connector at one side of the inner surface of the inlet, housing; An elastic means inserted into the bow inlet and exerting elasticity such that the AE sensor moves away from the housing; And a signal processing module electrically connected to the second connector and incorporated in the housing, for processing and transmitting the acoustic emission signal sensed by the AE sensor.

The signal processing module includes an amplifier unit for amplifying and band-filtering an acoustic emission signal sensed by the AE sensor; A digital signal processor for converting the amplified and band-filtered signal into a digital signal for wavelet filtering; And a first short range wireless communication unit for short-distance transmission of the wavelet-filtered signal, wherein the third connector is provided at one side of the outer surface of the housing and is electrically connected to the signal processing module. The first short range wireless communication unit may be a ZigBee, a Bluetooth, an Ultra WideBand (UWB), a WiFi (WiFi) , Worldwide Interoperability for Microwave Access (ISM), and Industrial Scientific and Medical (ISM).

According to another aspect of the present invention, there is provided a fault diagnosis system for a high-pressure piping using the above-described sensor device, comprising: a central signal processing unit for receiving a signal transmitted from the signal processing module in a short distance and calculating a defect, The present invention provides a wireless fault diagnosis system for a high-pressure piping including a high-

In this case, the central signal processing unit may include a second short range wireless communication unit for receiving the short distance transmitted signal; And a calculation unit which calculates the presence / absence of defects, the degree of defects, and the position of defects by calculating the signal on the basis of the mounting position and the sensing point of time of the sensing unit, wherein the second short range wireless communication unit includes a ZigBee, And is a method selected from among Bluetooth, Ultra WideBand (UWB), WiFi, Worldwide Interoperability for Microwave Access, and ISM (Industrial Scientific and Medical) And a relaying unit for relaying the local communication between the signal processing module and the central signal processing unit.

The present invention utilizes an acoustic emission signal to diagnose a defect in a durable structure for an industrial facility. Therefore, it is possible to continuously diagnose a defect with high sensitivity, and it can be applied even when the accessibility is limited due to the structure of the internal structure, .

Particularly, the AE sensor device according to the present invention can be easily fixed to a flat surface such as a high-pressure pipe as well as a flat surface, and furthermore, since wireless communication is possible, a cable connection process can be omitted, Can be greatly reduced.

In addition, the defect diagnosis system according to the present invention can effectively remove and analyze unnecessary noises from the acoustic emission signals collected by the wireless communication method in the field, thereby improving the objectivity and accuracy of the signal analysis, Based on the local expression method and the time-of-arrival method, a database-based optimization correction process can accurately position the defect location.

In addition, the defect diagnosis system according to the present invention can more effectively manage the defect information by transmitting the defect information to the user in various ways on / off-line.

Hereinafter, the present invention will be described in detail with reference to the drawings.

Prior to realizing some of the main terms to be referred to herein, an 'acoustic emission signal' refers to a high frequency signal in the 20 to 500 kHz band including an audible signal, an acoustic emission, and an acoustic vibration signal. In the following, the object of the defect diagnosis is assumed to be 'high-pressure piping' for convenience, but the present invention can be applied to all kinds of industrial facilities if a curved magnetic body is used, and can be easily understood by those skilled in the art through the following description.

1 is a perspective view of an AE sensor device 10 according to an embodiment of the present invention, FIG. 2 is an exploded perspective view, and FIG. 3 is a cross-sectional view taken along line III-III of FIG.

As shown, the AE sensor device 10 according to the present invention includes a cylindrical AE sensor 20 which is in close contact with a high-pressure pipe, a housing 12 of an insulating material which covers and accommodates the rest of the AE sensor 20, And a signal processing module 30 built in the housing 12 and electrically connected to the AE sensor 20.

Each of them is as follows.

First, the AE sensor 20 is a portion that is closely attached to a high-pressure pipe and detects an acoustic emission signal. The bottom surface of the AE sensor 20 closely contacting the high-pressure pipe shows a cylindrical shape with a predetermined height. A first connector (22) is provided on one side of the AE sensor (20).

In this case, preferably, the first connector 22 is provided on the upper surface opposite to the bottom surface, and further detailed description and operation of the AE sensor 20 can be widely applied to the AE sensor 20, .

Next, the housing 12 is a portion for pressing the bottom surface of the AE sensor 20 against the high-pressure pipe and for electrically connecting the signal processing module 30 and the AE sensor 20, and at least one magnet 16 And a second connector 18 is provided on one side of the inner surface of the entry port 13. The second connector 18 is provided on the inner surface of the entry port 13,

Preferably, the second connector 18 is provided on the opposite face of the entry opening 13 opposite to the upper face of the AE sensor 20, and the depth of the entry opening 13 is larger than the depth of the entry opening 13 when the AE sensor 20 is inserted The bottom surface of the housing 13 and the bottom surface of the AE sensor 20 are matched or appropriately exposed to a certain degree and a third connector 14 (not shown), which is electrically connected to a signal processing module 30 .

Therefore, when the AE sensor 20 is inserted into the entry port 13 of the housing 12, the first and second connectors 22 and 18 are physically coupled and the bottom surface of the AE sensor 20 is connected to the housing 12 And the first to third connectors 22, 18, 14 and the signal processing module are electrically connected to each other.

Next, the signal processing module 30 processes and transmits the acoustic emission signal sensed by the AE sensor 20.

1 to 3, the signal processing module 30 includes an amplifier unit 32, a digital signal processing unit 34, a digital signal processing unit 34, 1 short range wireless communication unit 36.

At this time, the amplifier unit 32 amplifies and filters the acoustic emission signal transmitted from the AE sensor 20, and includes an amplifier and at least one band filter.

The digital signal processing unit 34 converts the analog acoustic emission signal transmitted from the amplifier unit 32 into a digital signal and then performs predetermined filtering. The digital signal processing unit 34 includes a digital filter, a first And includes an application.

In this case, preferably, the digital signal processor 34 obtains a digital signal using parameters such as RMS, Amplitude, Rising Time, Duration time, Ring down count, Event, Energy and Peak Frequency, adaptive filtering of wavelet transform according to time-scale can be performed. The signal definition of the main variable is as shown in FIG. 5, and the time-scale wavelet transform is a signal transformation method that appropriately adjusts the window according to time and frequency. The wavelet transformation is performed by scaling and shifting Noise reduction method. The wavelet transform is well known in the art and can be easily understood by those skilled in the art even if the detailed explanation is omitted, and it is disclosed in detail in the registered patent No. 10-0883446 by the present applicant.

Further, the first short range wireless communication unit 36 transmits the digital signal of the digital signal processing unit 34 at a short distance. The first short range wireless communication unit 36 for this purpose may be a ZigBee, a Bluetooth, an Ultra WideBand (UWB), a WiFi, a Worldwide Interoperability for Microwave Access (ISM) and Medical) are used.

1 to 3, the AE sensor device 10 according to the present invention is preferably provided with a separate battery pack B and is connected to the AE sensor (not shown) through the third connector 14 of the housing 12 20 and the signal processing module 30, respectively. And the reference character C denotes a separate connector C for connecting the battery pack B to the third connector 14.

As a result, the AE sensor device 10 according to the present invention is attached to the high-pressure pipe in a state in which the AE sensor 10 is inserted into the intestinal entrance 13 of the housing 12, ) Exerts a strong electromagnetic attraction on the high-pressure pipe as a magnetic body, and tightly adheres the bottom surface of the AE sensor 10 to the surface of the high-pressure pipe on the curved surface. When the battery pack B is connected to the third connector 14 of the housing 12, the AE sensor 20 senses an acoustic emission signal transmitted from the high-pressure pipe, and outputs the acoustic emission signal sensed by the AE sensor 20 Is converted into a digital signal during the process of passing through the amplifier unit 32 of the signal processing module 30 and the digital signal processing unit 34 and wirelessly transmitted in real time via the first short range wireless communication unit 36. [

At this time, a switch for on / off controlling power supply of the battery pack B may be provided on one side of the housing 12 if necessary.

And preferably the elastic inlet 19 of the housing 12 is provided with elastic means 19 for exerting the AE sensor 20 away from the housing 12 so that the AE sensor 20 is more closely contacted to the high- Preferably the resilient means 19 is interposed between the upper surface of the AE sensor 20 and the opposing face of the intestinal mouth 13 so as to surround the outer peripheries of the first and second connectors 22, A coil spring may be used.

Hereinafter, a wireless fault diagnosis system (defect diagnosis system) of the high-pressure pipe according to the present invention using the AE sensor device 10 will be described below. Referring properly to FIGS. 1 to 3 above.

FIG. 6 is a schematic diagram of a defect diagnosis system according to the present invention. The system includes at least one AE sensor device 10, a central signal processor 50 for short-range wireless communication with the AE sensor device 10, a central signal processor 50, And an interface unit 60 and a user terminal 70 which are wired and wirelessly connected to each other.

First, the AE sensor device 10 is as described above, and at least one of the AE sensor devices 10 is closely mounted to the high-pressure pipe. At this time, the signal detectable range of the AE sensor device 10 preferably overlaps with each other.

Next, the central signal processing unit 50 receives the signals transmitted from the at least one AE sensor device 10 in a short distance, and calculates the presence or absence of defects, defects, and defects in the high-pressure pipe.

More specifically, FIG. 7 attached hereto includes a second short range wireless communication unit 52 and a calculation unit 54 as a schematic diagram showing the central signal processing unit 50 in brief.

The second short range wireless communication unit 52 may be one or more of a ZigBee, a Bluetooth, an Ultra WideBand (UWB), a WiFi, a Worldwide Interoperability for Microwave Access (ISM), an Industrial Scientic and Medical The first short range wireless communication unit 36 of the signal processing module 30 built in the housing 12 of the AE sensor device 10 in a selected one of the two types of wireless communication units.

The calculation unit 54 calculates the time delay of the AE sensor device 10 using a cross-correlation based on the at least one digital signal received by the second short-range wireless communication unit 52, Based on the mounting position and sensing point of the AE sensor device 10, the results of the first position look-up are obtained by using the regional expression method and the arrival time difference method, and then the second position is expressed through an optimal correction process based on the database, The defective position is calculated.

The operation unit 54 for this purpose includes a second application dedicated to performing an operation according to a predetermined algorithm, a memory as a substantial database, and a central processing unit (CPU) for overall control and operation do. The structure and characteristics of the sensing object, such as the high-pressure pipe, and the mounting position of the AE sensor device 10 are input to the database of the calculation unit 54 by the user in advance.

Here, the calculation method of the calculation unit 54 will be described in more detail. The area facial method is a method of calculating the effective measurement sensitivity range of the AE sensor device 10 instead of determining the defect position of the internal structure by a point, For example, when the bare-mouth position is difficult, for example, a sound velocity is applied to other anisotropic materials depending on the propagation direction, welding materials having the same propagation direction, high attenuation materials and the like. The arrival time difference method is a method of obtaining a defect position at the detection time point of each of the AE sensor devices 10, that is, the arrival time difference, and performs the position based on the signal detection order among the AE sensor devices 10. In addition, the optimal calibration process based on the database reflects the database-based calibration, such as the velocity weighting on the welds, in the primary position look-up results obtained by the regional expression method and the time-of-arrival method, Obtain accurate position expression results.

8 is a schematic diagram showing a positional expression process by the calculation unit 54. As shown in FIG.

First, as shown in (a), the location of the defect is estimated based on the local facial expression by the regional facial expression method and the arrival time difference result by the arrival time difference method. Subsequently, as shown in (c), the position of the defect is reflected by reflecting the correction amount based on the database, for example, the position of the welding portion P and the variation rate of the propagation speed of the acceleration signal and the acoustic emission signal, And calculates an accurate defect position.

In summary, the position lookup by the arithmetic unit 54 is based on the area expression method based on the mounting position of the AE sensor device 10, the arrival time difference method based on the sensing time of the AE sensor device 10, Based optimization correction process.

Referring again to FIG. 6, a relay unit 40 may be interposed between the at least one AE sensor device 10 and the central signal processing unit 50. This is for relaying wireless communication, and a publicly known technical content can be widely applied.

The defect diagnosis system according to the present invention may include a central signal processor 50 and an interface unit 60 and a user terminal 70 connected to the central signal processor 50 in a wired or wireless manner. (See 56 in Fig. 7, the same will apply hereinafter).

At this time, the communication unit 56 wirelessly transmits the calculation result of the calculation unit 54 to the interface unit 60 and the user terminal 70, such as whether or not the high-pressure pipe is defective, the degree of defectiveness,

The communication unit 56 for this purpose includes a message generation module for generating a message for a mobile phone such as a short message service (SMS) or a multimedia messaging service (MMS), an internet protocol such as a transmission control protocol- ), And interworks with an external relay system such as a communication server or a base station or a web server that provides a web page of a URL, if necessary, and sends the calculation result to the interface unit 60 for wire transmission And wirelessly transmits the calculation result to the user terminal 70 through at least one of SMS, MMS or the Internet.

The interface unit 60 provides the user interface environment such as displaying the calculation result of the calculation unit 54 to the user.

9 is a block diagram briefly showing the interface unit 60, which includes a display unit 62 such as a monitor for displaying a calculation result of the central signal processing unit 50, An alarm unit 64 such as a speaker that emits an audible warning sound when a defect is detected or a degree of defect becomes severe and preferably includes an operation unit 54 of the central signal processing unit 50, And a local terminal 66 for controlling the operation unit 62, the alarm unit 64, and the like.

At this time, the local terminal 66 can be used as a local computer, and the user can input and change the appropriate variable and / or setting environment to the operation unit 54 of the central signal processing unit 50 using the local terminal 66 , And selects and switches the position expression method of the calculation unit 54, thereby utilizing the defect diagnosis system according to the present invention as a purpose suitable for the purpose. The interface unit 60 may also be provided with a separate remote controller 68 that performs part or all of the functions of the local terminal 66 to further facilitate the defect diagnosis system Can be controlled and utilized.

Finally, the user terminal 70 of FIG. 6 includes a cellular phone and a client computer capable of accessing the Internet. Accordingly, the user can easily check the result of calculation of the central signal processing unit 50 in real time by connecting to the Internet through the user terminal 70, or confirm the result of defect through SMS or MMS of the mobile phone.

At this time, the SMS or MMS of the mobile phone may be regularly or irregularly received, and it may be received when the calculation result of the central signal processing unit 50 is equal to or greater than the predetermined reference value. In addition, a dedicated program for displaying the calculation result of the central signal processing unit 50 as a three-dimensional image can be mounted on the client computer, so that the user can more easily grasp the defect position and the like.

Below. A defect diagnosis method according to the present invention will be described.

10 is a schematic diagram illustrating a method for diagnosing defects in a high-pressure pipe using the AE sensor apparatus 10 and the defect diagnosis system according to the present invention. With reference to FIGS. 1 to 8, which have been described above.

First, at least one AE sensor device 10 is attached to an internal structure for defect diagnosis, for example, a high-pressure pipe. (St1)

At this time, the AE sensor device 10 has the AE sensor 20 embedded in the intestinal inlet 13 formed in the bottom of the housing 12 to expose the bottom surface of the AE sensor 20, The bottom surface of the AE sensor 20 is tightly adhered to the high-pressure pipe by the magnet 16. And the battery pack B is connected to the third connector 14 so that the AE sensor 20 receives the acoustic vibration signal generated from the high-pressure pipe, and the signal processing module 30 receives the acoustic signal received by the AE sensor 20 Converts the vibration signal into an appropriate digital signal and wirelessly transmits it in real time (st2)

The relay unit 40 relays the digital signal of the AE sensor device 10 in real time. (St3)

Accordingly, the central signal processing unit 50 determines whether or not the high-pressure pipe has a defect, the degree of defect, and the position of the defect. The specific method has been described in detail above. The calculation result is transmitted to the interface unit 60 and the user terminal 70 by wire or wireless.

Accordingly, the user can perform real-time defect diagnosis using the interface unit 60, and the administrator at a remote location from the interface unit 40 can confirm the calculation result with the user terminal 70. [ For example, if the user terminal 70 is a client computer, the position of the defective point may be displayed as one or more points while the shape of the high-pressure pipe is displayed as a three-dimensional image.

The above description is merely an example for explaining a preferred embodiment of the present invention, and various modifications may be made. It is to be understood, however, that all such modifications are intended to be within the scope of the present invention as long as they satisfy the technical spirit of the present invention, and the scope of the present invention will be readily apparent to those skilled in the art from the following claims.

1 is a perspective view of an AE sensor device according to the present invention.

2 is an exploded perspective view of an AE sensor device according to the present invention.

3 is a cross-sectional view taken along line III-III of FIG.

4 is a schematic diagram of a signal processing module of an AE sensor device according to the present invention.

5 is a variable diagram of a signal processing module of an AE sensor device according to the present invention.

6 is a schematic diagram of a defect diagnosis system according to the present invention.

7 is a schematic diagram of a central signal processing unit of the defect diagnosis system according to the present invention.

FIG. 8 is a schematic view illustrating a process of determining a position of a defect diagnosis system according to the present invention. FIG.

9 is a schematic diagram of an interface unit of a defect diagnosis system according to the present invention;

10 is a schematic diagram of a defect diagnosis method using a defect diagnosis system according to the present invention.

Description of the Related Art

10: AE sensor device 12: housing

13: entryway 16: magnet

18: elastic means 22, 18, 14: first to third connectors

20: AE sensor

Claims (8)

An AE sensor having a first connector on one side and a substantially horizontal bottom surface which is in close contact with a high-pressure pipe which is a magnetic body of a curved surface; Wherein the AE sensor is housed in the bottom surface of the at least one magnet to expose the bottom surface and the second connector is coupled to the first connector at one side of the inner surface of the inlet, housing; An elastic means inserted into the bow inlet and exerting elasticity such that the AE sensor moves away from the housing; And And a signal processing module that is electrically connected to the second connector and is embedded in the housing, processes and processes the acoustic emission signal sensed by the AE sensor, Wherein the signal processing module comprises: An amplifier unit for amplifying and band-filtering an acoustic emission signal sensed by the AE sensor; A digital signal processor for converting the amplified and band-filtered signal into a digital signal for wavelet filtering; And And a first short range wireless communication unit for transmitting the wavelet filtered signal in a short distance. delete The method according to claim 1, A third connector provided on one side of the outer surface of the housing and electrically connected to the signal processing module; And And a battery pack connected to the third connector. The method according to claim 1, The first short range wireless communication unit may be one of ZigBee, Bluetooth, Ultra WideBand (UWB), WiFi, Worldwide Interoperability for Microwave Access (ISM), Industrial Scientific and Medical The sensor device of an acoustic emission signal selected one way. A defect diagnosis system for a high-pressure pipe using the sensor device according to any one of claims 1, 3 and 4, And a central signal processing unit for receiving a signal transmitted from the signal processing module in a short distance and calculating a defect, defect degree, and defect position of the high-pressure pipe. The method of claim 5, The central signal processing unit, A second short range wireless communication unit for receiving the short distance transmitted signal; And And an arithmetic unit for calculating the presence / absence of defects, the degree of defects, and the position of defects by calculating the signal based on a mounting position and a sensing point of time of the sensor device. The method of claim 6, The second short range wireless communication unit may be one of ZigBee, Bluetooth, Ultra WideBand (UWB), WiFi, Worldwide Interoperability for Microwave Access (ISM), Industrial Scientific and Medical A wireless fault diagnosis system for high pressure piping, which is selected one way. The method of claim 5, Further comprising a relay for relaying the local communication between the signal processing module and the central signal processing unit.

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