JPWO2013065351A1 - Water leakage search device and water leakage search method - Google Patents

Abstract

An object of the present invention is to search for a water leak location of a buried non-conductive pipe.
A leak detection device 10 for searching for a leak point 60 of an embedded non-conductive pipe 20, and circulates in the non-conductive pipe 20 through a metal body 80 attached to the non-conductive pipe 20. The transmission unit 11 that transmits the high-frequency current 40 to the conductive fluid 30, the reception unit 12 that receives the electromagnetic wave 50 generated by the high-frequency current 40 from the outside 70 of the nonconductive pipe 20, and the strength of the received electromagnetic wave 50 And a reporting unit 13 for reporting a water leak location 60. [Selection] FIG.

Description

  The present invention relates to a water leak search device and a water leak search method for searching for a water leak location of an embedded non-conductive pipe.

  Water supply and drainage pipes may leak due to damage due to natural disasters such as earthquakes or aging due to long-term use. Conventionally, in the investigation of the water leakage point of the water supply / drainage pipe, the worker listens to the water leakage sound using a sound stick and estimates the water leakage point from the water leakage sound. When the exact location of the pipeline is not known in advance, the location of the pipeline is confirmed using a metal detector or the like, and then the location of the water leak is investigated.

  However, in the method of listening to the leaked sound, the worker must have a skilled skill to recognize the noise that is very similar to the leaked sound, and even if there is that skill, the worker can hear the leaked sound in a work environment where the noise is severe. However, it was a difficult task. Further, when the water supply / drainage pipe is formed of a material other than metal, such as a vinyl chloride pipe (including a form in which a metal cable is wound around the water supply / drainage pipe), the buried position cannot be confirmed.

  As one means for solving such a problem, there is an invention disclosed in Patent Document 1 below. In this invention, a conductive locating wire is laid along the pipe line, and an electromagnetic wave generated by a high-frequency current flowing in the locating wire is detected on the ground surface to detect the buried position of the water supply / drainage pipe and the water leakage location. Yes.

JP-A-11-270772

  In order to carry out the invention disclosed in Patent Document 1 and search for a water leak point in a water supply / drainage pipe, it is essential that a conductive locating wire is laid or can be laid at least along the pipe line. It is. Moreover, since the switching means connected to the locating wire is provided only at a predetermined location, it is possible to detect only water leakage occurring within a predetermined range.

  However, in practice, a conductive locating wire cannot often be laid along the existing existing pipe line, and water leakage does not always occur only at the location where the switching means is provided.

  The present invention has been made in view of the above circumstances, and has been embedded by using a conductive fluid that circulates in the non-conductive pipe without modifying the existing non-conductive pipe. An object of the present invention is to provide a water leak search device and a water leak search method capable of easily searching for a water leak location of a non-conductive pipe.

  In order to achieve the above object, a water leak search apparatus according to the present invention includes a transmission unit, a reception unit, and a notification unit.

  The transmission unit transmits a high-frequency current to a conductive fluid flowing through the nonconductive pipe via a metal body attached to the nonconductive pipe.

  The receiving unit receives electromagnetic waves generated by the high-frequency current from the outside of the nonconductive pipe.

  The reporting unit reports the location of water leakage based on the strength of the received electromagnetic waves.

  A water leakage search method according to the present invention for achieving the above object includes a transmission step of transmitting a high-frequency current to a conductive fluid flowing through a non-conductive pipe through a metal body attached to the non-conductive pipe; Receiving the electromagnetic wave generated by the high-frequency current from the outside of the non-conductive pipe, receiving the non-conductive pipe line specifying stage for specifying the burying position of the non-conductive pipe, and receiving the specified non-conductive pipe line. The location of the water leak is searched by carrying out the reporting stage of reporting the location of the water leak by the strength of the electromagnetic wave.

  According to the water leak search apparatus according to the present invention, it is possible to easily detect a water leak location without requiring a skilled worker who can distinguish a water leak sound and without taking any special measures for non-conductive piping.

  According to the water leak search method according to the present invention, it is not necessary to search for a pipeline in advance, and a water leak location can be easily detected while searching for a pipeline.

It is an external view of the transmission part of the water leak search apparatus which concerns on this embodiment. It is an external view of the receiving part and report part of the water leak search apparatus which concern on this embodiment. It is an image figure of a water leak search using the water leak search apparatus which concerns on this embodiment. It is a figure which shows the input sensitivity of the electromagnetic waves detected by the X direction of FIG. It is a figure which shows the electromagnetic wave intensity | strength in the Y direction of the electromagnetic wave produced | generated centering on the nonelectroconductive piping of FIG. It is an operation | movement flowchart of the water leak search apparatus which concerns on this embodiment. It is a subroutine flowchart of step S100 of the operation flowchart of FIG. It is a subroutine flowchart of step S300 of the operation flowchart of FIG. It is an image figure of the pipe line search of FIG. It is a subroutine flowchart of step S400 of the operation | movement flowchart of FIG. It is an image figure of electromagnetic wave reception in the position A corresponding to the water leak location of FIG.

  Hereinafter, embodiments of a water leak search device and a water leak search method of the present invention will be described in detail with reference to the accompanying drawings.

  The water leakage search device and the water leakage search method according to the present embodiment flow a high-frequency current through a conductive fluid flowing through a non-conductive pipe and recognize the strength of the magnetic field of the high-frequency current flowing along the conductive fluid from the outside. To identify the location of water leakage in the non-conductive piping. The strength of the magnetic field that can be recognized from the outside is drastically attenuated at the leak point. For this reason, even when the conductive fluid is not pumped through the non-conductive pipe, the location of water leakage can be easily identified.

  In the present embodiment, the non-conductive pipe is assumed to be, for example, a PVC pipe. However, it is not limited to a PVC pipe, but includes, for example, pipes that are made conductive by covering the outer periphery of the conductive pipe with a conductive material.

  In the present embodiment, the conductive fluid is assumed to be water (tap water, groundwater, etc.). However, it is not limited to water, and for example, if the fluid has a conductivity of 5 μS / cm or more, the location of water leakage can be specified.

(Configuration of leak detection device)
FIG. 1 is an external view of a transmission unit of the water leak search apparatus according to the present embodiment. FIG. 2 is an external view of the receiving unit and the reporting unit of the water leak search apparatus according to the present embodiment. FIG. 3 is an image diagram of a water leak search using the water leak search apparatus according to the present embodiment.

  As shown in FIG. 3, the leak detection device 10 includes a transmission unit 11, a reception unit 12, and a notification unit 13.

  As shown in FIG. 1, the transmission unit 11 includes a transmission output adjustment unit 111, an impedance adjustment unit 112, a transmission output display unit 113, and a positive terminal connected to the metal body 80 and a negative terminal connected to the ground electrode.

  The transmission unit 11 transmits the high-frequency current 40 from the + terminal to the conductive fluid 30 flowing through the non-conductive pipe 20 via the metal body 80 attached to the non-conductive pipe 20. The high-frequency current 40 generates an electromagnetic wave 50 around the nonconductive pipe 20.

  The transmission output adjustment unit 111 adjusts the transmission output intensity of the high-frequency current 40. By adjusting the transmission output intensity according to the pipe length of the non-conductive pipe 20, the attenuation of the electromagnetic wave intensity according to the pipe length is corrected.

  The impedance adjustment unit 112 adapts the impedance of the conductive fluid 30. The current component of the high-frequency current 40 is recognized by adapting the impedance of the conductive fluid 30 having different impedance characteristics.

  The transmission output display unit 113 displays the transmission output intensity of the high-frequency current 40 in real time. The operator adjusts the transmission output intensity while confirming the display of the transmission output intensity.

  As illustrated in FIG. 2, the receiving unit 12 includes an antenna 121, a grip 122, and a box 123. The box 123 includes a reception sensitivity adjustment unit 124. The box 123 may further include a sound generator 125. The receiving unit 12 receives an electromagnetic wave 50 generated by the high-frequency current 40 from the outside 70.

  The antenna 121 captures the electromagnetic wave 50 generated by the high-frequency current 40 near the ground surface of the exterior 70 or the wall surface of the building. Although the shape of the antenna 121 and the way to attach the grip 122 are arbitrary, it is preferable that the antenna 121 is attached to the T-shape. The directionality is clear, and it is easy to follow the diversion part and the bending part of non-conductive pipes by making use of this.

  The reception sensitivity adjustment unit 124 adjusts the reception sensitivity according to the strength of the captured electromagnetic wave 50. By increasing the reception sensitivity, the electromagnetic wave 50 having a relatively low intensity can be detected. As shown in FIG. 3, the electromagnetic wave input sensitivity is extremely reduced at the water leakage location 60, so that it is necessary to increase the reception sensitivity in order to accurately identify the water leakage location. On the other hand, by reducing the reception sensitivity, it becomes possible to detect the electromagnetic wave 50 having a relatively strong intensity, and conversely, the electromagnetic wave 50 having a relatively low intensity cannot be detected.

  The sound generator 125 generates sound having a magnitude corresponding to the input sensitivity of electromagnetic waves. The operator can confirm the embedded position of the non-conductive pipe 20 according to the magnitude of the sound.

  As shown in FIG. 2, the reporting unit 13 is attached in the box 123 of the receiving unit 12. The reporting unit 13 reports the water leakage location 60 based on the strength of the received electromagnetic wave 50. At the position A of the external 70 corresponding to the water leaking point 60, the receiving unit 12 attenuates more than the intensity of the electromagnetic wave detected at the other part, so that the input sensitivity of the electromagnetic wave is lower than the other part. The reporting unit 13 reports the location of water leakage by displaying the input sensitivity of the electromagnetic wave 50 with respect to the reception sensitivity adjusted by the reception sensitivity adjustment unit 124. The sound generation unit 125 can also report. Detailed operation of the reporting unit 13 will be described later.

  FIG. 3 is an image diagram of a water leak search using the water leak search apparatus 10 according to the present invention.

  As shown in FIG. 3, a non-conductive pipe 20 is embedded in the ground or the wall of a building. A metal body 80 connected from the outside 70 is attached to the non-conductive pipe 20. In the non-conductive pipe 20, the conductive fluid 30 circulates, and if there is a damaged part in the non-conductive pipe 20, water leakage occurs at the water leak point 60.

  The leak detection device 10 according to the present invention transmits the high-frequency current 40 from the + end of the transmission unit 11 to the conductive fluid 30 flowing through the nonconductive pipe 20 via the metal body 80. The negative end of the transmitter 11 is connected to the ground electrode. The electromagnetic wave 50 generated by the high-frequency current 40 from the receiving unit 12 is received by the external 70 and advanced in the illustrated search direction. The position A point of the external 70 corresponding to the water leak location 60 is specified by the strength of the electromagnetic wave received from the reporting unit 13.

  FIG. 4 is a diagram showing the input sensitivity of the electromagnetic wave detected in the X direction of FIG. In this figure, the vertical axis indicates the input sensitivity of the electromagnetic wave received by the receiving unit 12, and the horizontal axis indicates the distance X from the metal body 80 in the search direction shown in FIG.

  As is apparent from the figure, the input sensitivity of the electromagnetic wave received by the receiving unit 12 at the position A of the external 70 corresponding to the water leakage location 60 is more extreme than the input sensitivity of the electromagnetic wave received at other locations. It has decayed. The leak detection device 10 according to the present invention searches for a position where the input sensitivity of electromagnetic waves is extremely attenuated.

  FIG. 5 is a diagram illustrating the electromagnetic wave intensity in the Y direction of the electromagnetic wave 50 generated around the non-conductive pipe 20 of FIG. 3. In this figure, the vertical axis indicates the electromagnetic wave intensity generated by the high-frequency current 40, and the horizontal axis indicates the distance Y from the buried pipe, that is, the non-conductive pipe 20, to the outside 70 shown in FIG.

  As is apparent from the figure, the electromagnetic wave intensity attenuates in inverse proportion to the square of the distance Y as the distance Y increases.

(Operation of leak detection device)
Next, operation | movement of the water leak search apparatus 10 which concerns on this embodiment is demonstrated. FIG. 6 is an operation flowchart of the water leakage search apparatus 10 according to the present invention. In addition, the operation | movement flowchart shown in FIG. 6 also shows the procedure of the water leak search method which concerns on this embodiment.

  In the operation flowchart of FIG. 6, the operation of the step S100 is performed by an operator (searcher) of the leak detection device 10, and the operation of the step S200 is performed by the transmission unit 11. The operation of step S300 is performed by the receiving unit 12, and the operation of steps S400 to S600 is performed by the reporting unit 13.

<Step S100>
The operator of the water leak search device 10 shown in FIG. 3 prepares for electromagnetic wave intensity measurement for the transmitter 11 and the receiver 12 before the water leak search. Specific processing at this stage is shown in the flowchart of FIG. Detailed processing for preparing for electromagnetic wave intensity measurement will be described later.

<Step S200>
As shown in FIG. 3, the operator connects the + terminal of the transmitter 11 to the metal body 80 and embeds the ground electrode connected to the − terminal in the ground. The operator turns on the power of the transmission unit 11. The transmitter 11 continues to transmit the high-frequency current 40 that has been appropriately adjusted to the conductive fluid 30 in the electromagnetic wave intensity measurement preparation stage. The high-frequency current 40 flowing through the conductive fluid 30 generates an electromagnetic wave 50. The intensity of the electromagnetic wave 50 is such that the input sensitivity centered on the non-conductive pipe 20 can be easily searched from the outside 70.

<Step S300>
The operator positions the antenna 121 of the receiving unit 12 on the pipe path of the non-conductive pipe 20 and moves the antenna 121 along the pipe path of the non-conductive pipe 20. The receiving unit 12 receives the electromagnetic wave 50 generated around the non-conductive pipe 20. Detailed processing of electromagnetic wave reception on the pipeline will be described later.

<Step S400>
The operator moves the antenna 121 along the pipe path of the non-conductive pipe 20 and proceeds on the pipe path. As shown in FIG. 3, the intensity of the electromagnetic wave 50 received by the receiving unit 12 is extremely attenuated at the water leak location 60 of the non-conductive pipe 20. The reporting unit 13 outputs a report for specifying the water leakage location 60 when the intensity of the electromagnetic wave 50 is extremely attenuated. Detailed processing of the leak location search will be described later.

<Step S500>
It is determined whether or not the water leak location 60 has been detected. When the water leak location 60 is not detected, it moves to step S300 and searches for the water leak location 60 on the pipe line of the non-conductive pipe 20 ahead by the same method.

<Step S600>
When the water leak location 60 is detected, the operator is notified of water leak detection. The notification of water leakage detection may be performed by outputting a display of “water leakage detection” to the notification unit 13 or by outputting an alarm sound from the sound generation unit 125.

  Next, a subroutine flowchart showing detailed processing in steps S100, S300, and S400 will be described.

  FIG. 7 is a subroutine flowchart of step S100 of the operation flowchart of FIG.

<Step S101>
In the state where the + terminal of the transmitting unit 11 and the metal body 80 attached to the non-conductive pipe 20 in which the conductive fluid 30 circulates are connected by a cable, the − terminal of the transmitting unit 11 and the ground electrode are connected. The power supply of the unit 11 is turned on, and the high frequency current 40 is transmitted to the conductive fluid 30. The metal body 80 only needs to be in direct contact with the conductive fluid 30, such as a valve and a joint portion of the nonconductive pipe 20.

  The high-frequency current 40 flows into the conductive fluid 20 in the non-conductive pipe 20 due to an electrical shielding action between the non-conductive pipe 20 and the ground, and generates an electromagnetic wave 50 centering on the non-conductive pipe 20.

<Step S102>
From the transmission output adjustment unit 111, the transmission output intensity of the high-frequency current 40 is appropriately adjusted according to the pipe diameter of the non-conductive pipe 20 and the water leak search range. When the pipe diameter is large or the leak detection range is wide, the transmission output intensity is adjusted to be relatively large. It is preferable to adjust while confirming the display of the transmission output display unit 113.

  The impedance adjustment unit 112 adapts the impedance of the conductive fluid 30.

<Step S103>
The power of the receiving unit 12 is turned on, and the electromagnetic wave 50 generated by the high-frequency current 40 is captured near the ground or wall surface of the outside 70 from the antenna 121.

<Step S104>
The reception sensitivity adjustment unit 124 adjusts the reception sensitivity according to the strength of the captured electromagnetic wave 50. It is preferable to set the sensitivity so that a water leak search described later can be easily performed while confirming the display of the reporting unit 13. At this stage, the transmission output intensity is also adjusted as necessary to complete the preparation for electromagnetic wave intensity measurement.

  FIG. 8 is a subroutine flowchart of step S300 of the operation flowchart of FIG.

<Step S301>
A determination is made as to whether a search for a pipeline is necessary. When the burying position of the buried non-conductive pipe 20 is known before searching for the water leak location 60, the pipe path can be already identified, and therefore the search for the pipe path is unnecessary.

<Step S302>
When a search for a pipeline is necessary, it is further determined whether or not the search for the pipeline is a pipeline search from a branch position. When it is not the pipe line search from the diversion position, the search direction is also determined by the known pipe line, and the process proceeds directly to step S306.

  The diversion position may be the position of the joint portion and the valve portion of the two non-conductive pipes 20 exposed to the outside 70 as in the metal body 80 described above, but is not limited thereto, and is not embedded. The position of an arbitrary joint portion of the conductive pipe 20 is also included. A plurality of non-conductive pipes 20 are connected to each other depending on the buried position of the joint, and the conductive fluid 30 is diverted.

<Step S303>
When searching for a pipeline from a branch position, the search direction is not determined, and therefore the electromagnetic wave intensity is measured while receiving the surrounding electromagnetic wave 50 around the branch position.

<Step S304>
In the electromagnetic wave 50 received in the surroundings, it is determined that the nonconductive pipe 20 is embedded at a position where the input sensitivity of the electromagnetic wave 50 is relatively high, and the pipe path is specified.

  When a plurality of non-conductive pipes 20 are embedded, the input sensitivity of electromagnetic waves at the embedded positions of the non-conductive pipes 20 may be different from each other, but the input sensitivity is relatively high within each search range ( Therefore, the pipeline can be specified.

<Step S305>
One of the identified one or a plurality of pipelines is selected, and the direction from the branch position is determined as the search direction.

<Step S306>
The electromagnetic wave 50 is received while moving the receiving unit 12 in the direction crossing the search direction in the search direction, and the electromagnetic wave intensity is measured.

<Step S307>
Among the electromagnetic waves 50 received in the direction crossing the search direction, it is determined that the non-conductive pipe 20 is buried at a position where the input sensitivity of the electromagnetic wave is relatively high, and the pipe path is specified.

  FIG. 9 is an image of a pipeline search image. As shown in FIG. 5, the electromagnetic wave 50 generated by the high-frequency current 40 flowing through the conductive fluid 30 in the nonconductive pipe 20 attenuates the electromagnetic wave intensity in inverse proportion to the square of the distance Y as the distance Y increases. .

  The electromagnetic wave 50a having a relatively high electromagnetic wave intensity is received at the position B of the outside 70 away from the center of the non-conductive pipe 20, and the input sensitivity of the electromagnetic wave is relatively high. On the other hand, an electromagnetic wave 50b having a relatively low electromagnetic wave intensity is received at positions C and D of the outside 70 that are separated from the center of the non-conductive pipe 20 by a distance b (b> a), and the input sensitivity of the electromagnetic wave is also relatively high. Very low.

  Accordingly, it is determined that the non-conductive pipe 20 is embedded at the external 70 position B point where the electromagnetic wave input sensitivity is relatively high, and the pipe path is specified.

  FIG. 10 is a subroutine flowchart of step S400 in the operation flowchart of FIG.

<Step S401>
Measure the electromagnetic wave intensity on the pipe line of the specified non-conductive pipe 20, confirm the change of input sensitivity of the received electromagnetic wave 50 from the display of the notification unit 13, and whether the input sensitivity suddenly drops (extreme attenuation)? Judge whether or not. If the sudden drop in the input sensitivity of the electromagnetic wave 50 has not occurred, the reporting unit 13 determines that the water leakage location has not been detected.

<Step S402>
If there is a sudden drop in the input sensitivity of the electromagnetic wave 50, the reception sensitivity adjustment unit 124 increases the reception sensitivity.

  Even when the embedment depth of the non-conductive pipe 20 becomes deep, a sudden drop in the input sensitivity of the electromagnetic wave 50 occurs. However, by increasing the reception sensitivity, an electromagnetic wave having a relatively weak intensity can be detected.

  On the other hand, at the water leakage location 60, as shown in FIG. 11, the conductive fluid 30 in the non-conductive pipe 20 is short-circuited with the ground, and instead of receiving the electromagnetic wave 50d having the normal electromagnetic wave intensity, the electromagnetic wave intensity is increased. The electromagnetic wave 50c that is significantly attenuated is received. In this case, even if the receiving sensitivity is increased, it is difficult to obtain the input sensitivity of the electromagnetic wave 50c.

  Furthermore, when the previous piping path is advanced in the search direction through the water leakage point 60, the input sensitivity of the electromagnetic wave 50 gradually increases again. This is because the high-frequency current 40 flows through the conductive fluid 30 that has not leaked at the water leakage location 60, so that the strength of the electromagnetic wave 50 is increased again.

  On the other hand, the input sensitivity of the electromagnetic wave 50 does not change much even if the reception sensitivity changed due to the change in the embedding depth of the non-conductive pipe 20 even if the pipe line ahead is advanced in the search direction.

  Therefore, the reporting unit 13 can determine that the water leak location 60 has been detected.

<Step S403>
It is determined whether or not the input sensitivity of the electromagnetic wave 50 can be obtained again by increasing the reception sensitivity. When the input sensitivity of the electromagnetic wave 50 is obtained again, the reporting unit 13 determines that the water leak location 60 has not been detected.

<Step S404>
If the input sensitivity of the electromagnetic wave 50 is not obtained even when the reception sensitivity is increased, the reporting unit 13 determines that the water leak location 60 has been detected.

  As described above, according to the water leakage search device according to the present embodiment, it is possible to easily locate a water leakage point without requiring a skilled worker who can distinguish a water leakage sound and without taking special measures for non-conductive piping. Can be detected. Moreover, according to the water leak search method according to the present embodiment, it is not necessary to search for a pipeline in advance, and a leak location can be easily detected while searching for a pipeline.

  The preferred embodiments of the present invention have been described above, but these are examples for explaining the present invention, and the scope of the present invention is not intended to be limited to these embodiments. The present invention can be implemented in various modes different from the above-described embodiments without departing from the gist thereof.

10 Water leak detection device,
11 Transmitter,
12 Receiver,
13 Report Department,
20 non-conductive piping,
30 conductive fluid,
40 high frequency current,
50 electromagnetic waves,
60 water leakage points,
70 outside,
80 metal objects,
111 transmission output adjustment unit,
112 impedance adjustment unit,
113 Transmission output display section,
121 antenna,
122 grip,
123 boxes,
124 reception sensitivity adjustment unit,
125 Sound generator.

Claims (8)

A leak detection device that searches for leak points of buried non-conductive pipes,
A transmission unit for transmitting a high-frequency current to a conductive fluid flowing through the non-conductive pipe through a metal body attached to the non-conductive pipe;
A receiver that receives electromagnetic waves generated by the high-frequency current from outside the non-conductive pipe;
A reporting unit for reporting a water leakage location by the strength of the received electromagnetic wave;
A leak detection device comprising:   2. The water leakage point according to claim 1, wherein, in the water leakage point, the reporting unit reports the water leakage point using a characteristic that the receiving unit attenuates more than the intensity of the electromagnetic wave detected at another point. Search device. The transmitter is
A transmission output adjusting unit for adjusting the transmission output intensity of the high-frequency current;
An impedance adjuster for adapting the impedance of the conductive fluid;
A transmission output display unit for displaying the transmission output intensity of the high-frequency current;
The water leak search device according to claim 1 or 2, characterized by comprising: The receiver is
An antenna for capturing the electromagnetic wave;
A reception sensitivity adjustment unit that adjusts the reception sensitivity according to the strength of the captured electromagnetic wave;
The water leak search device according to any one of claims 1 to 3, wherein the water leak search device is provided.   The water leak search device according to any one of claims 1 to 4, further comprising a sound generation unit that generates sound having a magnitude corresponding to the input sensitivity. A water leak search method for searching for a water leak location of a buried non-conductive pipe,
A transmission step of transmitting a high-frequency current to a conductive fluid flowing through the non-conductive pipe through a metal body attached to the non-conductive pipe;
Receiving the electromagnetic wave generated by the high-frequency current from outside the non-conductive pipe;
A non-conductive pipe line specifying stage for specifying a buried position of the non-conductive pipe;
A reporting stage for reporting a water leak location by the strength of the electromagnetic wave received by the specified non-conductive pipe line,
A water leak search method comprising: In the non-conductive pipe line identification stage,
Utilizing the characteristic that the electromagnetic wave detected at the buried position of the non-conductive pipe attenuates more than the intensity of the electromagnetic wave detected around the buried position in the direction intersecting the non-conductive pipe line, it is non-conductive The water leakage search method according to claim 6, wherein a buried position of the pipe is specified. In the reporting stage of reporting the water leak location,
The leak detection method according to claim 6 or 7, wherein the leak location is reported using a characteristic that the leak location attenuates more than the strength of electromagnetic waves detected at other locations.

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