JP2011141249A - Moisture detection system in building and sheet for detecting moisture used therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a moisture detection system in a building which detects the entry of water such as a roof leak extremely easily and inexpensively, and a sheet for detecting moisture used therefor. <P>SOLUTION: A resonant structure 10 comprising a closed circuit including a planar coil wound with a conductor and having a given resonant frequency is attached to the back side of a test member 1. The radiation unit 22 of a test device 20 radiates an electromagnetic wave with the same frequency as the resonant frequency of the resonant structure 10 to the outside, and a receiving unit 23 receives the electromagnetic wave with the same frequency as the resonant frequency of the resonant structure 10. The electromagnetic wave strength detection unit 24 of the test device 20 detects the strength of the electromagnetic wave with the same frequency as the resonant frequency of the resonant structure 10 received by the receiving unit 23. As a result, the moisture between the resonant structure 10 and the test member 1 is detected based on the strength of the electromagnetic wave which is radiated from the resonant structure 10 attached to the test member 1 depending on the radiation wave radiated from the front side of the test member 1 by the radiation unit 22, and received by the receiving unit 23. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a moisture detection system in a building and a moisture detection sheet used therefor, and more particularly, to a technique for non-destructively detecting moisture that has entered the back of a wall or the ceiling of a building.

  In the building, in order to prevent the occurrence of rain leakage and the like, the outer shell portion is waterproofed. As this type of waterproofing treatment, sheet waterproofing for laying a waterproof sheet, asphalt waterproofing for laying asphalt, and the like are known. However, even if such waterproofing is performed, the waterproof performance decreases with the passage of time, and rain leakage occurs. Similarly, it is almost impossible to completely eliminate the occurrence of water leakage or water leakage from piping or the like disposed on the back of the wall or the ceiling.

  If rain leakage or water leakage is left unattended, there is a possibility of serious damage to the building itself or the inside of the building. Therefore, it is necessary to identify and repair these places. However, rain leaks often invade gradually over a long period of time, and the intrusion route is a part that is not normally visible, such as the back of a wall or the back of a ceiling, so rain leaks are detected at the initial stage. It is extremely difficult. In addition, when changes in ceilings and wall surfaces caused by invading water can be recognized from indoors, the damage inside the building often progresses considerably.

  Therefore, various methods for detecting rain leaks and the like have been proposed. For example, Patent Document 1 discloses a technique for detecting an intrusion route using a plurality of colors of colored water. In addition, Patent Document 2 installs a tactile switch means composed of two conductive wires that are held in a water-soluble substance and juxtaposed apart from each other between a ground floor of a building and a waterproof layer, A technique for detecting an intrusion route by utilizing the fact that the tactile water switch means operates when it comes into contact with water is disclosed. Furthermore, Patent Document 3 temporarily arranges a large number of electrodes on a waterproof layer via a conductor layer, and any one of the electrodes is a reference electrode, and any one of the other electrodes is an internal current electrode. A method is disclosed in which electricity is passed between an external current electrode and an internal current electrode set on the ground, and the degree of deterioration of the waterproof layer is diagnosed by a potential difference between the reference electrode and each electrode.

JP 2002-277343 A JP 2002-55015 A JP 2005-274242 A

  However, the technique disclosed in Patent Document 1 is effective when detecting the inundation path after the inundation is confirmed indoors or the like, but whether or not the inundation has occurred when the inundation cannot be confirmed from the indoors or the like. It is not effective when determining whether or not. Even when the inundation cannot be confirmed indoors, by using this method, the occurrence of inundation can be confirmed if the colored water can be confirmed indoors.However, in this case, the ceiling material and wall material are damaged by the colored water. receive.

  Further, the technique disclosed in Patent Document 2 requires the installation of wiring or the like for detecting the operation of the tactile water switch means. It is also assumed that disconnection may occur due to corrosion of the wiring due to water immersion. In this case, since it becomes indistinguishable from the non-actuated state of the tactile water switch means, it is necessary to constantly monitor whether or not the tactile water switch means is activated. In other words, since it is necessary to always connect the detector, it cannot be realized with simple equipment.

  Furthermore, the technique disclosed in Patent Document 3 requires the use of a high-output power source for energizing between the external current electrode and the internal current electrode, or a high-precision detector for detecting a minute potential difference. It becomes an expensive system.

  The present invention has been proposed in view of the above-described conventional circumstances, and is capable of detecting inundation such as rain leakage in a very simple and inexpensive manner. An object is to provide a detection sheet.

  In order to achieve the above object, the present invention employs the following technical means. First, a moisture detection system in a building according to the present invention includes a resonance structure and an inspection device provided on the back side of a member to be inspected constituting the building. The resonance structure is configured by a closed circuit having a predetermined resonance frequency including a planar coil around which a conductor is wound. The inspection device includes a radiation unit, a reception unit, and an electromagnetic wave intensity detection unit. The radiating unit radiates an electromagnetic wave having the same frequency as the resonance frequency of the resonant structure to the outside. The receiving unit receives an electromagnetic wave having the same frequency as the resonance frequency of the resonance structure. The electromagnetic wave intensity detector detects the intensity of the electromagnetic wave having the same frequency as the resonance frequency of the resonant structure received by the receiver. And this moisture detection system is the intensity | strength of the electromagnetic wave radiated | emitted from the resonance structure provided in the to-be-tested member according to the radiation wave which the radiation | emission part radiated | emitted from the surface side of the to-be-inspected member, and received by the receiving part. Based on the above, moisture between the resonance structure and the member to be inspected is detected.

  In this moisture detection system, a resonance structure is disposed on the back side of a member to be inspected such as a wall material, a ceiling material, or a waterproof sheet installed on the roof, and the resonance structure is provided from the surface side of the member to be inspected. By irradiating an electromagnetic wave having the same frequency as the resonance frequency of the resonance structure, moisture that has entered between the member to be inspected and the resonance structure can be detected. That is, the intrusion of moisture can be detected even in an initial state in which infiltration is not visible from the surface side of the member to be inspected (for example, indoor side or roof side). Therefore, it is possible to repair the flooded site before serious damage due to flooding occurs. The resonance structure may be directly formed on the back side of the member to be inspected by printing or the like, or may be provided by sticking the sheet on which the resonance structure is formed on the back side of the member to be inspected.

  In the moisture detection system, the resonance structure can be configured as a passive circuit including only passive elements as components. In this configuration, the resonant structure can be manufactured at a low cost, and the failure occurrence rate of the resonant structure can be reduced.

  Moreover, it is preferable that the resonant structure is periodically arranged with reference to a reference position set for the member to be inspected. Thereby, since the position which should irradiate electromagnetic waves from a test | inspection apparatus can be easily specified from the surface side of a to-be-inspected member, it can test | inspect efficiently.

  Furthermore, the inspection apparatus may further include a frequency changing unit that changes the frequency of the radiated electromagnetic wave and the frequency of the received electromagnetic wave. For example, when a part of the resonant structure is corroded and broken due to water immersion, the resonance frequency fluctuates, and thus this configuration makes it possible to detect the disconnection of the resonant structure.

  On the other hand, in another aspect, the present invention can provide a moisture detection sheet used for moisture detection in a building. The sheet for moisture detection according to the present invention includes a planar coil formed on a film substrate and conductor wiring that electrically connects both ends of the planar coil. The planar coil is on at least one surface side of the film substrate. It is formed by winding a conductor. The conductor wiring is formed on one side or the other side of the film substrate. In addition, when a conductor wiring cross | intersects the conductor which comprises a planar coil, a conductor wiring and the conductor which comprises a planar coil are electrically isolate | separated.

  By adhering this moisture detection sheet to the back side of a member to be inspected such as a gypsum board or a waterproof sheet, moisture detection by the above-described moisture detection system can be realized.

  Moreover, the film base material can employ | adopt the structure which has a through-hole which connects one surface side and the other surface side. In this configuration, moisture that has penetrated to the vicinity of the planar coil easily enters between the planar coil and the member to be inspected through the through-hole, so that the moisture detection accuracy can be further increased.

  In the moisture detection sheet, a plurality of the planar coils may be periodically arranged on a film substrate. In this configuration, the plurality of planar coils can be easily arranged on the member to be inspected.

  According to the moisture detection system of the present invention, it is possible to detect inundation such as rain leakage very easily and inexpensively and non-destructively.

  Further, according to the moisture detection sheet of the present invention, the resonance structure can be easily and inexpensively installed on the member to be inspected.

The schematic block diagram which shows the moisture detection system in one Embodiment of this invention. The schematic diagram which shows an example of the resonance structure in one Embodiment of this invention The circuit diagram which shows an example of the inspection apparatus in one Embodiment of this invention The schematic diagram which shows the arrangement | sequence method of the resonance structure in one Embodiment of this invention The schematic block diagram which shows the other application example of the moisture detection system in one Embodiment of this invention. The schematic diagram which shows an example of the sheet | seat for a moisture detection in one Embodiment of this invention. The schematic diagram which shows the other example of the sheet | seat for a moisture detection in one Embodiment of this invention.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following embodiments, the present invention is embodied mainly by an example in which the member to be inspected is a wall material such as a gypsum board.

  FIG. 1 is a schematic configuration diagram showing a schematic configuration of a moisture detection system in the present embodiment. As shown in FIG. 1, the moisture detection system of the present embodiment includes a resonance structure 10 and an inspection device 20 provided on the back side of the gypsum board 1. Here, the surface side of the gypsum board 1 is a surface exposed to the indoor side, and the back surface side is the opposite surface. The gypsum board 1 is installed in a building such as a house with one or a plurality of resonance structures 10 provided on the back side.

  The resonant structure 10 is configured by a closed circuit including a planar coil around which a conductor is wound. The resonant structure 10 has a predetermined resonant frequency f0. FIG. 2 is a schematic diagram illustrating an example of the resonant structure 10. As shown in FIG. 2, the resonance structure 10 includes a closed circuit 13 including a planar coil 11 around which a conductor is wound and a conductor wiring 12 that electrically connects both ends of the planar coil 11, for example, polypropylene (PP ), Polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyimide (PI), and the like. In this example, the conductor is made of a copper foil having a width of 8 mm (thickness t = 30 μm), and the planar coil 11 having a linear spiral shape is formed. As shown in FIG. 2, the straight spiral shape is a spiral shape formed by connecting only the straight line portions at right angles with only the straight line portions as components. In addition, the space | interval (space width) of an adjacent parallel linear part is 8 mm, and the external shape of the base material 14 is 260 mm x 260 mm. The resonance frequency f0 is adjusted by the line width, space width, and line length. Here, the line length is adjusted so that the resonance frequency f0 = 13.56 MHz. Further, as shown in FIG. 2, the inner end 11 a and the outer end 11 b of the planar coil 11 are connected by a conductor wiring 12. The conductor wiring 12 intersects with the straight line portion existing between the inner end portion 11a and the outer end portion 11b, but an insulator is disposed between the conductor wiring 12 and the straight line portion of the planar coil 11. Alternatively, the conductor wiring 12 is electrically separated by forming it on the opposite surface of the substrate 14. Here, the resonance structure 10 is formed on the base material 14, and the planar coil non-formation surface side of the base material 14 is attached to the gypsum board 1. However, the planar coil forming surface side of the base material 14 may be affixed to the gypsum board 1, and the planar coil 11 may be directly formed on the back surface side of the gypsum board 1.

  On the other hand, as shown in FIG. 1, the inspection device 20 includes an antenna 21, a radiation unit 22, a reception unit 23, and an electromagnetic wave intensity detection unit 24. The radiating unit 22 radiates an electromagnetic wave having the same frequency as the resonance frequency f 0 of the resonant structure 10 to the outside through the antenna 21. The receiving unit 23 receives an electromagnetic wave having the same frequency as the resonance frequency f <b> 0 of the resonance structure 10 through the antenna 21. The electromagnetic wave intensity detector 24 detects the intensity of the electromagnetic wave having the same frequency as the resonance frequency f0 of the resonant structure 10 received by the receiver 23. In the present embodiment, the intensity of the electromagnetic wave is a DC potential corresponding to the amplitude of the electromagnetic wave. Further, although not particularly limited, in the present embodiment, the antenna 21 is formed of a planar coil having the same shape as the planar coil 11 of the resonance structure 10.

  FIG. 3 is a circuit diagram illustrating an example of a specific circuit configuration of the inspection apparatus 20. In the example of FIG. 3, the radiating unit 22 is configured by an oscillation circuit in which the antenna 21 is a part (inductor) of the Colpitts oscillation circuit. In this configuration, the radiation unit 22 also serves as the reception unit 23, and the electromagnetic wave intensity detection unit 24 measures a DC potential corresponding to the oscillation amplitude of the oscillation circuit. In the example of FIG. 3, the variable capacitors 27 and 28 (frequency changing units) are arranged in parallel with the antenna 21. By changing the capacitance values of the variable capacitors 27 and 28, the oscillation of the oscillation circuit is performed. The frequency, that is, the frequency of the electromagnetic wave radiated by the radiating unit 22 and the frequency of the electromagnetic wave received by the receiving unit 23 can be changed. The frequency can be acquired by the frequency detection unit 25.

  In the moisture detection system having the above configuration, when moisture detection is performed, the inspection device 20 is disposed at a position facing the resonance structure 10 with the gypsum board 1 interposed therebetween. More specifically, the center of the planar coil 11 constituting the resonance structure 10 and the center of the planar coil constituting the antenna 21 face each other, and the planar coil constituting the antenna 21 is the gypsum board 1. A state parallel to the surface, that is, both planar coils are arranged in parallel. The antenna 21 may be arranged in contact with the surface side of the gypsum board 1, but here, a predetermined interval (about 30 mm) is provided. In addition, when the said space | interval is widened, naturally the electromagnetic wave intensity | strength will fall. That is, the upper limit of the interval is a distance at which the following moisture detection is possible, and the distance depends on the output power of the electromagnetic wave radiated through the antenna 21 by the radiating unit 22.

  Whether or not the centers of the two planar coils coincide can be detected by the output value of the electromagnetic wave intensity detector 24 (hereinafter referred to as electromagnetic wave intensity). That is, when the frequency of the electromagnetic wave emitted by the radiating unit 22 is set to the resonance frequency f0 and the antenna 21 is moved along the surface of the gypsum board 1, the electromagnetic wave intensity becomes maximum when the centers coincide. However, since such an operation is complicated, the resonant structure 10 may be installed at a predetermined position based on a predetermined reference position (for example, a corner or the center) of the gypsum board 1. Good. Thereby, the center of the planar coil 11 constituting the resonance structure 10 and the center of the planar coil constituting the antenna 21 can be easily opposed to each other. Here, it is assumed that the plurality of resonant structures 10 are periodically arranged with reference to the reference position. In the following description, unless stated otherwise, the fact that the resonant structure 10 and the antenna 21 face each other means that the centers of both planar coils coincide with each other.

  When moisture exists between the gypsum board 1 and the resonance structure 10, the electromagnetic wave intensity varies because the state between the resonance structure 10 and the antenna 21 is different from the case where moisture does not exist. Specifically, the electromagnetic wave intensity in the state with moisture is smaller than the electromagnetic wave intensity in the state without moisture. Therefore, the presence or absence of moisture can be determined by utilizing the property.

  The determination can be performed based on the absolute value of each electromagnetic wave intensity acquired when each resonance structure 10 and the antenna 21 are opposed to each other, and can also be performed by relative comparison of each electromagnetic wave intensity.

  When moisture detection is performed based on the absolute value of electromagnetic wave intensity, a reference value for determining the presence or absence of moisture is set in advance. Since the electromagnetic wave intensity fluctuates when the positional relationship between the planar coil 11 and the antenna 21 is different, the reference value is determined in a state where the positional relationship is fixed. Here, the positional relationship is the distance between the planar coil 11 and the antenna 21, the rotation angle of both planar coils (whether both planar coil linear portions are parallel or in a torsional positional relationship), the planar coil 11 and the antenna. 21 (the presence or absence of other objects). Accordingly, a reference value corresponding to the thickness of the gypsum board 1 to be inspected is selected, and moisture is maintained in a state in which the positional relationship between the resonant structure 10 and the antenna 21 matches the positional relationship when the reference value is acquired. Detection will be performed. Since the fluctuation of the electromagnetic wave intensity due to the presence or absence of moisture is as described above, the reference value can be set to a value obtained by subtracting a predetermined margin value from the electromagnetic wave intensity in the absence of moisture. In addition, when the inspection apparatus 20 stores the reference value and acquires the electromagnetic wave intensity, it may be configured to automatically determine the presence or absence of moisture by comparing the magnitude relationship with the reference value.

  On the other hand, when moisture detection is performed by relative comparison of electromagnetic wave intensity, the electromagnetic wave intensity may be compared using any one of the resonance structures 10 as a reference. In this case, when moisture enters between the resonant structure 10 and the gypsum board 1, an electromagnetic wave intensity smaller than the electromagnetic wave intensity at other positions is detected. Since the thickness is the same for the same gypsum board 1, it is not necessary to select a reference value according to the thickness of the gypsum board 1 in advance as in the case of the determination based on the absolute value of the electromagnetic wave intensity described above. Moisture detection can be performed. In addition, the positional relationship between the resonant structure 10 and the antenna 21 may be maintained while acquiring the electromagnetic wave intensity for performing the relative comparison. The inspection device 20 may store a reference value for relative comparison, and when the electromagnetic wave intensity is acquired, the presence / absence of moisture may be automatically determined by comparing the magnitude relationship with the reference value.

  If a spacer (bar material or plate material) that makes the distance from the gypsum board 1 constant is installed on the surface of the antenna 21, the antenna 21 can be easily arranged at a constant distance with respect to the gypsum board 1 to be inspected. be able to.

  Here, a specific detection example is illustrated in Table 1. Table 1 shows the electromagnetic wave intensity when moisture (10 cc) is infiltrated between the resonant structure 10 and the gypsum board 1 shown in FIG. 2 and when there is no moisture. The gypsum board has a thickness of 9.5 mm and 15 mm. The electromagnetic wave intensity for the same gypsum board is measured with the same distance between the gypsum board surface and the antenna 21. The frequency of the electromagnetic wave radiated from the antenna 21 is 13.56 MHz, and the output power is about 1 mW. Further, the electromagnetic wave intensity in a state where it is not opposed to the resonance structure 10 and the electromagnetic wave intensity when the planar coil 11 of the resonance structure 10 is disconnected are shown together.

  From Table 1, it can be understood that the presence or absence of moisture can be clearly identified. Further, when a break occurs in the planar coil 11, the electromagnetic wave intensity is comparable to that in the case where moisture is present. However, the decrease in electromagnetic wave intensity at a frequency of 13.56 MHz is a result of fluctuations in the resonance frequency. That is, different values are obtained depending on the location where the disconnection occurs in the planar coil 11, but in this example, as shown in Table 1, the resonance frequency f0 fluctuates to less than 12 MHz, resulting in 13.56 MHz. The electromagnetic wave intensity at has decreased. Therefore, presence of moisture and disconnection can be clearly distinguished by detecting the resonance frequency. As described above, since the inspection apparatus 20 includes the frequency changing unit (variable capacitors 27 and 28), the resonance frequency is changed by the frequency changing unit, and the peak of the electromagnetic wave intensity is shifted to another frequency. By confirming this, it is possible to confirm the presence or absence of fluctuations in the resonance frequency. The frequency can be detected by the frequency detection unit 25. The inspection apparatus 20 may be configured to automatically execute the confirmation process of the presence or absence of the resonance frequency fluctuation and display the resonance frequency together with the electromagnetic wave intensity.

  In this embodiment, since the resonant structure 10 is composed of only passive elements, it is unlikely that a disconnection will occur in a situation where no abnormality has occurred. Occurrence of an abnormality such as disconnection due to the above is assumed. That is, even if the frequency is not detected, it can be said that moisture intrusion and disconnection can be reliably detected.

  The electromagnetic wave intensity varies depending on the state between the resonant structure 10 and the antenna 21. However, even if an object is present on the opposite side of the gypsum board 1 across the resonant structure 10, the electromagnetic wave intensity is almost the same. Not affected. For example, a metal sash, which is a conductor, on the opposite side of the gypsum board 1 with the resonance structure 10 interposed therebetween is brought into contact with the resonance structure 10 in proximity or with an insulator interposed so that the planar coil 11 is not short-circuited. Even when arranged in a state, the fluctuation of the electromagnetic wave intensity could not be confirmed.

  FIG. 4 is a schematic diagram illustrating an arrangement example of the resonance structures 10. As described above, it is preferable that the resonance structure 10 is periodically arranged with reference to the reference position set in the gypsum board 1. For example, as shown in FIG. 4A, the resonant structure 10 can be arranged on the entire back surface side of the gypsum board 1. Moreover, as shown in FIG.4 (b), the resonant structure 10 can also be arranged in matrix form at equal intervals on the back surface side of the gypsum board 1. FIG. Furthermore, as shown in FIG. 4C, the resonance structures 10 can be arranged in a matrix by changing the arrangement interval in the vertical direction and the horizontal direction. Further, as shown in FIG. 4D, the resonance structures 10 can be arranged by shifting by half a period in adjacent columns.

  Although the case where the member to be inspected is a gypsum board has been described above, the present invention can also be applied to a waterproof sheet installed on a rooftop or the like. Hereinafter, the example which applied this invention to the waterproof sheet is demonstrated easily. FIG. 5 is a schematic configuration diagram illustrating an example in which the above-described moisture detection system is applied to a waterproof sheet. As shown in FIG. 5, a plurality of resonance structures 10 are arranged and attached to the back surface side of the waterproof sheet 2, for example, in a matrix. Here, the front surface side of the waterproof sheet 2 is the roof side surface, and the back surface side is the opposite surface (surface on the building side). A protective layer 3 made of concrete, asphalt, wood or the like is provided on the waterproof sheet 2, and the state of the waterproof sheet 2 cannot be visually recognized.

  In this state, when the protective layer 3 and the waterproof sheet 2 are deteriorated and a crack or the like is generated in the waterproof sheet 2, rainwater enters under the waterproof sheet 2. At this time, when moisture permeates between the resonant structure 10 and the waterproof sheet 2, the penetration of moisture is easily detected by measuring the electromagnetic wave intensity with the above-described detection device 20 facing the resonant structure 10. can do. Therefore, by removing only the protective layer 3 where moisture has been detected and repairing the waterproof sheet 2, it is possible to prevent the building from being seriously damaged. Moreover, if the water | moisture content permeated between the resonance structure 10 and the waterproof sheet 2 can be dried at the time of the said repair, it is also possible to use the resonance structure 10 as it is.

  As described above, in this moisture detection system, a resonance structure is arranged on the back side of a member to be inspected such as a wall material, a ceiling material, or a waterproof sheet installed on the roof, and the surface side of the member to be inspected. By irradiating the resonance structure with electromagnetic waves having the same resonance frequency as the resonance structure, moisture that has entered between the member to be inspected and the resonance structure can be detected. That is, the intrusion of moisture can be detected even in an initial state in which infiltration is not visible from the surface side of the member to be inspected (for example, indoor side or roof side). Therefore, it is possible to repair the flooded site before serious damage due to flooding occurs.

  Subsequently, a moisture detection sheet used for the moisture detection described above will be described. FIG. 6 is a schematic view showing a moisture detection sheet of the present embodiment. The said moisture detection sheet | seat is affixed on the back surface side of to-be-inspected members, such as a gypsum board and a waterproof sheet, for example.

  As shown in FIG. 6, this moisture detection sheet 30 is formed on at least one surface side of a film substrate 31, and includes a planar coil 11 wound with a conductor, an inner end portion 11 a and an outer end portion of the planar coil 11. The resonance structure 10 is provided that includes a closed circuit 13 including a conductor wiring 12 that is electrically connected to 11b. As described above, the planar coil 11 has a linear spiral shape, and the conductor wiring 12 is formed on one surface side (formation surface side of the planar coil 11) or the other surface side of the film base 31. The straight line portion of the planar coil 11 that intersects the conductor wiring 12 and the conductor wiring 12 are electrically separated as described above. In addition, it is not essential that the planar coil 11 is formed only on one surface side of the film base 31. For example, a linear portion group that forms an opposing linear portion group on one surface and intersects the linear portion group at a right angle. May be formed on the other surface. In addition, as film base material 31, resin, such as a polypropylene (PP), a polyethylene terephthalate (PET), a polyphenylene sulfide (PPS), a polyimide (PI), can be used, for example. The conductor pattern can be formed by printing using a conductive paste, vapor deposition, or the like.

  Moreover, it is preferable that the film base material 31 has the through-hole 32 which connects one surface side and the other surface side. The through hole 32 can be formed at an arbitrary position such as the innermost part of the planar coil 11. In the example of FIG. 6, a plurality of through holes 32 are formed in the outer edge portion of the planar coil 11. In this configuration, moisture that has penetrated to the vicinity of the planar coil 11 easily enters between the planar coil 11 and the member to be inspected through the through-hole 32, so that the moisture detection accuracy can be further increased.

  FIG. 7 is a schematic diagram illustrating another example of the moisture detection sheet. In this example, a plurality of resonance structures 10 (planar coils 11) are periodically arranged on the film substrate 31. In this configuration, the plurality of resonance structures 10 can be easily arranged on the member to be inspected. FIG. 7 shows an example in which the resonance structures 10 are arranged in a line on the film base 31, but they may be arranged in a plurality of lines.

  As described above, the moisture detection sheet can be affixed to the back side of a member to be inspected such as a gypsum board or a waterproof sheet to realize moisture detection by the moisture detection system described above.

  As described above, according to the present invention, it is possible to detect inundation such as rain leakage very simply, inexpensively and non-destructively. Further, according to the moisture detection sheet of the present invention, the resonance structure can be easily and inexpensively installed on the member to be inspected.

  The above-described embodiments do not limit the technical scope of the present invention, and various modifications and applications other than those already described are possible within the scope of the present invention. For example, in the above embodiment, the planar coil is constituted by a straight spiral, but an arbitrary spiral shape such as a spiral shape having only a curved portion (spiral curve) or a spiral shape in which the straight portion is connected by a curved portion is adopted. can do. Further, if the resonance frequency can be adjusted, a single coil (loop antenna) may be used. Further, in the above, the resonant structure is composed of only passive elements from the viewpoint of cost reduction, but this does not preclude inclusion of active elements. In the above description, the resonance frequency of the resonance structure is 13.56 MHz. However, the present invention can be applied to any frequency. Furthermore, in the above description, the planar coil having the same shape as the planar coil of the resonance structure is used as the antenna of the inspection apparatus, but an antenna having another structure may be used. In addition, in the inspection apparatus, the radiation unit and the reception unit are configured in common, but each may be configured independently. In this case, the radiation antenna and the reception antenna may be provided independently.

  ADVANTAGE OF THE INVENTION According to this invention, the inundation resulting from a rain leak etc. can be detected very simply and cheaply, and it is useful as a moisture detection system in a building, and a moisture detection sheet used therefor.

1 Gypsum board (inspected member)
2 Waterproof sheet (inspected member)
DESCRIPTION OF SYMBOLS 3 Protective layer 10 Resonant structure 11 Planar coil 12 Conductor wiring 13 Closed circuit 14 Base material 20 Inspection apparatus 21 Antenna 22 Radiation part 23 Reception part 24 Electromagnetic wave intensity detection part 25 Frequency detection part 27, 28 Variable capacity capacitor (frequency change part)
30 Moisture detection sheet 31 Film substrate 32 Through hole

Claims (7)

A moisture detection system in a building,
A resonance structure configured by a closed circuit having a predetermined resonance frequency, including a planar coil wound with a conductor, provided on the back side of the member to be inspected;
A radiating portion for radiating electromagnetic waves having the same frequency as the resonant frequency of the resonant structure to the outside;
A receiver for receiving an electromagnetic wave having the same frequency as the resonant frequency of the resonant structure;
An electromagnetic wave intensity detector that detects the intensity of an electromagnetic wave having the same frequency as the resonance frequency of the resonant structure received by the receiver;
An inspection device comprising:
Have
From the surface side of the member to be inspected, the resonance structure and the device to be inspected are radiated from the resonance structure according to the radiated wave radiated by the radiation unit and received by the reception unit. A moisture detection system that detects moisture between members.   The moisture detection system according to claim 1, wherein the resonance structure is a passive circuit including only passive elements as components.   The moisture detection system according to claim 1 or 2, wherein the resonance structure is periodically arranged with reference to a reference position set in the member to be inspected.   The moisture detection system according to any one of claims 1 to 3, wherein the inspection device further includes a frequency changing unit that changes the frequency of the electromagnetic wave to be radiated and the frequency of the electromagnetic wave to be received. A moisture detection sheet used for moisture detection in buildings,
A planar coil formed by winding a conductor, formed on at least one side of the film substrate;
Conductor wiring that is formed on the one surface side or the other surface side of the film substrate and electrically connects both ends of the planar coil;
A sheet for moisture detection.   The moisture detection sheet according to claim 5, wherein the film base has a through-hole that communicates the one side and the other side.   The moisture detection sheet according to claim 5 or 6, wherein the plurality of planar coils are periodically arranged on the film base material.

Images