JP2020020701A - Corrosion protection current detector, reference electrode device, electric corrosion protection monitoring device, and jacket - Google Patents

Abstract

To provide a corrosion protection current detector, a reference electrode device, an electric corrosion protection monitoring device, and a jacket, which are less likely to be corroded or damaged at a wired part of a transmission line for transmitting data about electric corrosion protection.SOLUTION: Provided is a corrosion protection current detector 10 attached to a structure 100 having a steel member 106A below the surface of water, comprising: a detection component 14 for detecting a corrosion protection current and electrically connected at one end to a sacrificial anode 80 and electrically connected at another end to the steel member 106A; a sacrificial anode-side wiring part 16; a steel member-side wiring part 18; transmission line-side wiring parts 20, 22; and a wiring box 12 for accommodating the detection component 14, the sacrificial anode-side wiring part 16, the steel member-side wiring part 18 and the transmission line-side wiring parts 20, 22. The inside of the wiring box 12 is filled with a swelling resin 24 that swells upon absorbing a water content, and the detection component 14, the sacrificial anode-side wiring part 16, the steel member-side wiring part 18 and the transmission line-side wiring parts 20, 22 are covered with the swelling resin 24.SELECTED DRAWING: Figure 1

Description

  The present invention relates to equipment and devices used for sacrificial anode (electrolytic anode) type of cathodic protection, and more specifically, to a anticorrosion current detector, a reference electrode device, a cathodic protection monitoring device, and a jacket. Further, the present invention can be suitably applied to an anticorrosion facility that is assumed to be used for a long time. Hereinafter, in the present application, the notation of “sacrificial anode” is used in principle instead of the notation of “current-flowing anode”. Further, the “sacrificial anode” may be simply described as “anode”.

  BACKGROUND ART In a water body structure such as a harbor facility, a cathodic protection method is widely used to prevent corrosion of steel materials.

  The cathodic protection method is roughly classified into a sacrificial anode method and an external power supply method. Since the sacrificial anode method does not require adjustment of the amount of current, the maintenance burden is smaller than that of the external power supply method. However, even in the sacrificial anode-type cathodic protection system, it is necessary to periodically check that the cathodic protection is operating well and to check the remaining life of the sacrificial anode, and to perform maintenance.

  In the maintenance and management of sacrificial anode-type cathodic protection equipment, the potential measurement of the target structure in land work performed at the time of general periodic inspection, and the study of anode consumption during underwater work performed at the time of detailed inspection are mainly performed. The potential measurement of the target structure is performed to check the anti-corrosion state of the target structure, and the anode consumption test is performed to check the remaining life of the sacrificial anode.

  When the structure to be subjected to cathodic protection is a quay using a jacket-type pier, the potential measurement during onshore work is performed by suspending the reference electrode underwater from the quay normal (the seaside end of the quay). , Results can only be obtained at the quay normal (the seaside tip of the quay). Underwater work is usually required in order to check the anticorrosion state at a location other than the quay normal (the seaside end of the quay) (for example, a location on the land side). In addition, in order to predict the remaining life of the anode, it is usually necessary to investigate the consumption of the anode during underwater work, which usually requires underwater work.

  As a method of reducing the burden of inspections and surveys that require underwater work, a method for installing a generated current (corrosion protection current) measurement device on the anode, measuring the amount of generated current (corrosion protection current) by onshore work, and calculating the approximate remaining There is a method for calculating the life. In addition, there is a method in which a stationary zinc reference electrode is attached to a target structure in the sea, and the potential of the target structure is measured during onshore work.

  However, as described above, in the method of measuring the generated current amount (corrosion prevention current amount) and the potential of the target structure by land work, it is necessary to fix the transmission line on the outer surface of the target structure, and Such external force may cause physical damage to the transmission line.

  The life of the transmission line varies depending on the environment and the like, but the service life is said to be about 15 to 20 years. In a marine environment, it tends to be shorter. When the transmission line deteriorates, it is necessary to update it.

  Also, the shunt resistor, which is a component for detecting the anticorrosion current, has no long-term performance (the result of 50 years of dew condensation), and its long-term durability is unclear, so it may be necessary to replace it.

  On the other hand, Patent Literature 1 discloses a galvanic anode device used for a method of electrolytically protecting a metal structure, which includes a terminal for electrically connecting to the metal structure, and a galvanic anode and an electrical connection. Using a DC current measuring device having a terminal for connecting to the DC current measuring device, fix the core metal of the galvanic anode on the metal structure via an electrical insulator provided with an insertion port for the terminal of the DC current measuring device. Also, when the terminal is inserted into the insertion opening, the terminal for electrically connecting to the metal structure is electrically connected to the metal structure, and is also electrically connected to the cored bar. The terminal is electrically connected to the metal core, the galvanostatic device characterized by the fact that it is possible to measure the anticorrosion current by the DC current measuring device, further described in the In the galvanic anode device, the DC current measurement It has been described that preferably further detachably connecting a current measuring cable to the vessel.

JP 2005-264286 A

  In the technology described in Patent Literature 1, there is disclosed a configuration in which a DC current measuring device can be easily attached to and detached from a cathodic protection target facility, and a current measuring cable can be easily attached to and detached from the DC current measuring device. The connection between the current measuring device and the current measuring cable is in a state of being exposed to water. For this reason, the connection section may become unusable due to corrosion, and the connection section may be damaged and become unusable due to the influence of external forces such as waves and drifting substances, or the attachment and growth of marine organisms. There is.

  The present invention has been made in view of the above point, and a corrosion protection current detector that is less likely to be damaged by corrosion, external force, adhesion of marine organisms, and the like, at a connection portion of a transmission line that transmits data on cathodic protection. It is an object to provide a reference electrode device, an anticorrosion monitoring device, and a jacket.

  The present invention has solved the above-mentioned problems by the following anticorrosion current detector, reference electrode device, anticorrosion monitoring device, and jacket.

  That is, the anticorrosion current detector according to the present invention is an anticorrosion current detector attached to a structure having a steel member below the water surface and used for measuring an anticorrosion current flowing between the sacrificial anode and the steel member. And one end is electrically connected to the sacrificial anode, and the other end is electrically connected to the steel member, and is electrically connected to the detection component for detecting the anticorrosion current and the sacrificial anode. A sacrificial anode-side connection portion formed by electrically connecting a terminal and a terminal electrically connected to one end of the detection component; and a terminal electrically connected to the steel member and an electrical connection to the other end of the detection component. To a steel member-side connection portion electrically connected to a terminal connected to a terminal, and to an output terminal for outputting an electric signal about the anticorrosion current obtained by the detection component to the outside, and electrically connectable to an external device. One end of the external device connection transmission line And a connection box that houses the detection component, the sacrificial anode-side connection portion, the steel member-side connection portion, and the transmission line-side connection portion. The inside is filled with a swelling resin that swells by absorbing moisture, and the detection component, the sacrificial anode side connection portion, the steel member side connection portion, and the transmission line side connection portion are covered with the swelling resin. A corrosion protection current detector.

  The swelling resin is preferably composed of two kinds of swelling resins having different water-swelling swelling properties. As the two kinds of swelling resins having different water-swelling swelling properties, for example, the content of a water-absorbing polymer having a water-absorbing swelling property is 5 A curable paste-like urethane-based resin having a content of 0 to 40% by mass and a curable paste-like urethane-based resin having a content of a water-absorbing polymer having a water-absorbing swellability of 0 to 10% by mass may be used.

  Here, the “curable paste-like urethane-based resin” refers to a urethane-based resin that is in a paste state before filling, but is cured into an elastic body such as rubber when exposed to moisture of a certain degree or more.

  In at least one of the sacrificial anode-side connection portion, the steel member-side connection portion and the transmission line-side connection portion, a pair of terminals including a male terminal and a female terminal is used, and the male terminal It is preferable that the male terminal and the female terminal can be fitted and electrically connected by fitting the terminal and the female terminal and pushing in the fitting direction.

  The sacrificial anode side connection part, the steel member side connection part, and the transmission line side connection part are preferably covered with a cover on the outside.

  The reference electrode device according to the present invention is a reference electrode device that is attached to a structure having a steel member below the surface of the water, and is used for measuring potential data of the steel member. An output terminal for outputting potential data to the outside accommodates a transmission line side connection portion formed by electrically connecting one end of an external device connection transmission line electrically connectable to an external device, and the transmission line side connection portion. And a connection box, wherein the inside of the connection box is filled with a swelling resin, and the transmission-line-side connection portion is covered with the swelling resin.

  The swelling resin is preferably composed of two kinds of swelling resins having different water-swelling swelling properties. As the two kinds of swelling resins having different water-swelling swelling properties, for example, the content of a water-absorbing polymer having a water-absorbing swelling property is 5 A curable paste-like urethane-based resin having a content of 0 to 40% by mass and a curable paste-like urethane-based resin having a content of a water-absorbing polymer having a water-absorbing swellability of 0 to 10% by mass may be used.

  In the transmission line side connection portion of the reference electrode device, a pair of terminals including a male terminal and a female terminal is used, and the male terminal and the female terminal are fitted and the direction of fitting is performed. It is preferable that the male terminal and the female terminal can be fitted and electrically connected by pushing the male terminal into the male terminal.

  It is preferable that the outside of the transmission line side connection portion is covered with a cover.

  A first aspect of the cathodic protection monitoring device according to the present invention is a cathodic protection monitoring device used for cathodic protection of a structure having a steel member below the water surface, wherein the anticorrosion current detector and the anticorrosion current detector A monitoring unit that receives an electrical signal about the anticorrosion current, measures data about the anticorrosion current, and performs at least one of recording and displaying data about the measured anticorrosion current, and the anticorrosion current. A monitoring unit connection transmission line for transmitting the electrical signal of the monitoring unit to the monitoring unit, wherein the anticorrosion current detector is attached to the structure, and the external device connection transmission line is connected to the monitoring unit connection transmission line. One end of the monitoring unit connection transmission line is electrically connected to the output terminal of the anticorrosion current detector. It has been, forms the transmission line side connecting portion, the other end of the monitoring unit connecting transmission lines are cathodic protection monitoring apparatus characterized by being electrically connected to the monitoring unit.

  A second aspect of the cathodic protection monitoring device according to the present invention is a cathodic protection monitoring device used for cathodic protection of a structure having a steel member below the water surface, wherein the reference electrode device, the reference electrode, and the steel member A monitoring unit that receives an electric signal about the potential difference between the and the steel part and measures data about the potential of the steel member, and performs at least one of recording and displaying data about the measured potential of the steel member, A monitoring unit connection transmission line that transmits an electric signal from the reference electrode device to the monitoring unit, the reference electrode device is attached to the structure, and the external device connection transmission line is A monitoring unit connection transmission line, one end of the monitoring unit connection transmission line is electrically connected to the output terminal of the reference electrode device. It has been, forms the transmission line side connecting portion, the other end of the monitoring unit connecting transmission lines are cathodic protection monitoring apparatus characterized by being electrically connected to the monitoring unit.

  For example, a jacket may be adopted as the structure.

  Here, in the present application, the jacket is a frame structure mainly composed of a steel member, and the same applies to the description of other parts of the present application.

  When a jacket is adopted as the structure, it is preferable that the monitoring section connection transmission line reaches the transmission line side connection section via the inside of a steel pipe constituting the jacket.

  A first aspect of the jacket according to the present invention is a jacket to which the anticorrosion current detector is attached, wherein a portion to which the anticorrosion current detector is attached exists in water.

  A second aspect of the jacket according to the present invention is a jacket to which the reference electrode device is attached, wherein a portion where the reference electrode device is attached is in water.

  A third aspect of the jacket according to the present invention is a jacket to which the anticorrosion current detector and the reference electrode device are attached, wherein a portion where the anticorrosion current detector is attached and the reference electrode device are attached. The jacket is characterized in that the portion exists in the water.

  According to the present invention, there is provided an anticorrosion current detector, a reference electrode device, an anticorrosion monitoring device, and a jacket that are less likely to be damaged by corrosion, external force, adhesion of marine organisms, and the like on a transmission line that transmits data on cathodic protection. be able to.

Front view schematically showing a situation where the embodiment of the present invention is applied to a quay 200 of a jacket-type pier 100 (a front view as viewed from a direction along the quay 200). Front view showing a state where anticorrosion current detector 10 according to the embodiment of the present invention is attached to leg 106A of jacket 106. FIG. 2 is an enlarged front view showing the portions of the anticorrosion current detector 10 and the sacrificial anode 80 in FIG. FIG. 3 is an enlarged front view showing the portion of the anticorrosion current detector 10 in FIG. 3 in a further enlarged manner. Arrow view seen from the direction of arrow V in FIG. In the anticorrosion current detector 10, an enlarged front view showing a portion of a cored bar 84 and an insulating connecting portion 86 in an enlarged manner. Front view showing a state where reference electrode device 30 according to the embodiment of the present invention is attached to leg 106A of jacket 106. FIG. 7 is an enlarged front view showing an enlarged part of the reference electrode device 30 in FIG. 7. FIG. 8 is an enlarged front view showing the portion of the reference electrode device 30 in FIG. 8 in a further enlarged manner. The front view which shows typically the state in which the cathodic protection monitoring device 50 for corrosion protection current measurement which concerns on embodiment of this invention was applied to the jacket type pier 100. XI-XI line end view of FIG. FIG. 11 is an enlarged end view showing a portion XII of FIG. Enlarged vertical sectional view showing the upper end of leg 106A to which anticorrosion current detector 10 is attached in an enlarged manner (enlarged vertical sectional view cut along a vertical plane parallel to the longitudinal direction of steel girder 106B). Enlarged front view of steel girder 106B viewed from a horizontal direction orthogonal to its longitudinal direction. XV-XV line end view of FIG. The front view which shows typically the state in which the cathodic protection monitoring apparatus 60 for potential measurement which concerns on embodiment of this invention was applied to the jacket type pier 100. XVII-XVII line end view of FIG. FIG. 17 is an enlarged end view showing the XVIII part in FIG. 17 in an enlarged manner. An enlarged vertical cross-sectional view showing an enlarged upper end portion of the leg 106A to which the reference electrode device 30 is attached (an enlarged vertical cross-sectional view cut along a vertical plane parallel to the longitudinal direction of the steel girder 106B). Enlarged front view of steel girder 106B viewed from a horizontal direction orthogonal to its longitudinal direction. XXI-XXI line end view of FIG. 20

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, a case will be described in which an object of the cathodic protection performed using the embodiment of the present invention is a pier of a jacket-type pier.

  FIG. 1 shows an anticorrosion current detector 10 according to an embodiment of the present invention, a reference electrode device 30 according to an embodiment of the present invention, an anticorrosion monitoring device 50 for measuring anticorrosion current according to an embodiment of the present invention, It is a front view (front view seen from the direction along quay 200) showing typically the situation where cathodic protection monitoring device 60 for electric potential measurement concerning an embodiment is applied to quay 200 of jacket type pier 100. The jacket-type pier 100 has a structure in which a jacket 106 is attached to a steel pipe pile 104 cast on the seabed ground 102.

  As shown in FIG. 1, the sacrificial anode 80 can be mounted at an appropriate position on the jacket 106, and the anticorrosion current detector 10 and the reference electrode device 30 according to the present embodiment can be arranged at appropriate positions accordingly. it can.

  The transmission line 52 of the anticorrosion monitoring device 50 for measuring anticorrosion current according to the present embodiment is covered and protected by a protective tube 54 and is disposed inside the protective tube 54 (FIGS. 5 and 12 and the like). However, in the underwater portion, the protection tube 54 and the protection tube 54 are arranged in the inner space of the leg 106A of the jacket 106 (see FIGS. 5, 6, 11, 12, and the like). In addition, at the portion of the superstructure of the jacket 106, the protection tube 54 and the transmission line 52 inside the protection tube 54 are disposed along the steel girder 106B of the jacket 106 (see FIGS. 1, 10, 14, 15, and the like). ), The transmission line 52 reaches the monitoring unit 58.

  The transmission line 62 of the cathodic protection monitoring device 60 for potential measurement according to the present embodiment is covered and protected by a protective tube 64, and is disposed inside the protective tube 64 (see FIG. 18 and the like). In the underwater portion, the protection tube 64 and the protection tube 64 are disposed in the inner space of the leg 106A of the jacket 106 (see FIGS. 9, 17, 18, and the like). In the superstructure of the jacket 106, the protection tube 64 and the transmission line 62 inside the protection tube 64 are arranged along the steel girder 106B of the jacket 106 (see FIGS. 1, 16, 20, and 21). ), The transmission line 62 reaches the monitoring unit 68.

(1) Configuration and Effect of Anticorrosion Current Detector 10 FIG. 2 is a front view showing a state in which the anticorrosion current detector 10 according to the embodiment of the present invention is attached to the leg 106A of the jacket 106, and FIG. FIG. 4 is an enlarged front view showing an enlarged portion of the anticorrosion current detector 10 and the sacrificial anode 80 of FIG. 2, and FIG. 4 is an enlarged front view showing an enlarged portion of the anticorrosion current detector 10 of FIG. 3. . FIG. 5 is a view as seen from the direction of arrow V in FIG. 2 to 5, each component in the connection box 12 of the anticorrosion current detector 10 is indicated by a solid line instead of a broken line (hidden line).

  The anticorrosion current detector 10 according to the present embodiment includes a connection box 12, a detection component 14, a sacrificial anode-side connection portion 16, a steel member-side connection portion 18, transmission line-side connection portions 20, 22, and a swelling resin. 24.

  The connection box 12 is a box-shaped steel member, and is attached to a predetermined position on the outer peripheral surface of the leg 106A by welding. Inside the connection box 12, the detection component 14, the sacrificial anode-side connection portion 16, and the steel member-side connection are provided. Section 18 and the transmission line side connection sections 20 and 22 are housed therein. The connection box 12 is filled with a swelling resin 24, and the detection component 14, the sacrificial anode side connection section 16, the steel member side connection section 18, and the transmission line side connection stored in the connection box 12 are provided. Parts 20 and 22 are covered with swelling resin 24.

  The connection box 12 has a lid 12A, and can be opened when the transmission line 52 or the detection component 14 is replaced.

  The core box 82 of the sacrificial anode 80 is attached to the connection box 12 by bolts 82A and 82B. An insulating plate 12B is disposed between the core box 82 of the sacrificial anode 80 and the side surface of the connection box 12. Further, an insulating sleeve 12C is arranged around the shafts of the bolts 82A and 82B, and an insulating plate 12D is provided between the heads of the bolts 82A and 82B and the inner surface of the connection box 12. The direct connection between the core metal 82 of the sacrificial anode 80 and the connection box 12 and the electrical connection via the bolts 82A and 82B are prevented.

  Further, another core metal 84 of the sacrificial anode 80 is insulated and connected as shown in FIG. 6 (enlarged front view showing the core metal 84 and the insulating connection portion 86 in the anticorrosion current detector 10 in an enlarged manner). It is attached to the part 86 and is attached to the leg 106A via the insulating connection part 86. The insulated connecting portion 86 has a channel steel 86B attached to a predetermined position on the outer peripheral surface of the leg 106A by welding, and an insulating material 86A attached to the channel steel 86B with bolts 86C. 84 is attached to the insulating material 86A of the insulating connecting portion 86 by bolts 84A. Further, an insulating plate 86D is disposed between the core metal 84 of the sacrificial anode 80 and the side surface of the insulating connection portion 86, and an insulating sleeve 86E is disposed around the shaft of the bolt 84A. An insulating plate 86F is arranged between the head of the bolt 84A and the insulating sleeve 86E.

  The detection component 14 has one end 14A electrically connected to the sacrificial anode 80, and the other end 14B electrically connected to the leg 106A of the jacket 106, which is a steel structure. The anti-corrosion current flowing between them is detected. The electrical connection between the one end 14A of the detection component 14 and the sacrificial anode 80 is made via the cored bar 82, the bolt 82B, the connection fitting 83B, and the sacrificial anode side connection portion 16. Further, the electrical connection between the other end 14B of the detection component 14 and the leg 106A is made via the connection box 12, the bolt 82A, the connection fitting 83A, and the steel member side connection portion 18.

  As the detection component 14, the shunt resistor is used in the anticorrosion current detector 10 according to the present embodiment. However, the detection component 14 is not limited to the shunt resistance, and is connected between the sacrificial anode 80 and the leg 106A. Any detection component that can appropriately detect the flowing anticorrosion current can be used.

  The sacrificial anode side connection portion 16 is a connection portion for electrically connecting the terminal 16A electrically connected to the sacrificial anode 80 and the terminal 16B electrically connected to one end 14A of the detection component 14. In the sacrificial anode-side connection portion 16, a one-touch terminal is used, and the one-touch terminal is a pair of terminals including a male terminal and a female terminal. The male terminal and the female terminal are fitted together and pushed in the direction of fitting, whereby the male terminal and the female terminal are fitted together, and the terminals 16A and 16B are easily electrically connected. Can be connected. Therefore, in the sacrificial anode-side connection portion 16, the connection can be easily performed even in underwater work.

  The steel member side connection portion 18 is a connection portion for electrically connecting a terminal 18A electrically connected to the leg 106A of the jacket 106 and a terminal 18B electrically connected to the other end 14B of the detection component 14. . In the steel member side connection portion 18, a one-touch terminal is used, and the one-touch terminal is a pair of terminals including a male terminal and a female terminal. The male terminal and the female terminal are fitted together and pushed in the direction of fitting, whereby the male terminal and the female terminal are fitted and the terminals 18A and 18B are easily electrically connected. Can be connected. Therefore, in the steel member side connection part 18, even underwater work can be easily connected.

  The transmission line side connection section 20 electrically connects and connects a terminal 20A electrically connected to one end 14A of the detection component 14 and one terminal 20B of the two-core transmission line 52, and the transmission line side. The connection section 22 electrically connects and connects a terminal 22A electrically connected to the other end 14B of the detection component 14 and the other terminal 22B of the two-core transmission line 52. One-touch type terminals are used in the transmission line side connection portions 20 and 22. The one-touch type terminals are a pair of terminals including a male terminal and a female terminal. The male terminal and the female terminal are fitted together and pushed in the direction of fitting, whereby the male terminal and the female terminal are fitted together, and the terminals 20A and 20B are easily electrically connected. And the terminal 22A and the terminal 22B can be easily electrically connected. Therefore, the transmission line side connection portions 20 and 22 can be easily connected even in underwater work. 3 and 4, two transmission lines 52 are illustrated and two transmission line side connection portions are illustrated for convenience of explanation (the transmission line side connection portions 20 and 22 are illustrated). However, in practice, a two-core transmission line is usually used as the transmission line 52, and two core lines are included in one transmission line in appearance. In addition, a two-core type one-touch type terminal corresponding to the two-core transmission line 52 is also commercially available, and the transmission line side connection portions 20 and 22 can be included in one connection portion in appearance.

  The one-touch type terminals used in the sacrificial anode side connection portion 16, the steel member side connection portion 18, and the transmission line side connection portions 20 and 22 are provided with a cover (not shown) for further covering the connection portion from outside. . As such a one-touch type terminal, for example, a product of the TH387 series manufactured by Techno s.r.l. of Italy can be used.

  The swelling resin 24 is a resin that expands by absorbing moisture. Further, the swelling resin 24 has excellent shape followability, and when filled in the connection box 12, the detection component 14, the sacrificial anode-side connection section 16, the steel member-side connection section 18, and the detection component 14 housed in the connection box 12 are provided. The line-side connection parts 20 and 22 are closely covered with the swelling resin 24 and covered with the swelling resin 24 with moisture removed. For this reason, when the swelling resin 24 is filled in the connection box 12, the detection component 14, the sacrificial anode-side connection portion 16, the steel member-side connection portion 18, and the transmission line-side connection portions 20 and 22 maintain corrosion resistance. Held in state.

  In addition, the swelling resin 24 can maintain flexibility for a long time, and can be easily removed when the transmission line 52 or the detection component 14 is replaced.

  As the swelling resin 24, any resin having the above characteristics can be used.

  However, from the viewpoint of improving the filling property, it is preferable to use two types of swelling resins having different water absorption swelling properties as the swelling resin 24. Specifically, for example, a curable paste urethane resin (a first swelling resin having a large water-swelling property) in which the content of a water-absorbing polymer having a water-swelling property is 5 to 40% by mass is connected to the connection box 12. Is filled with about 50 to 90% of the space that can be filled, and thereafter, the content of the water-absorbing polymer having water-swelling property is 0 to 10% by mass. It is preferable to fill the remaining gap in the connection box 12 with the second swelling resin).

  Further, from the viewpoint of further improving the filling property, the first swelling resin preferably has a water-absorbing polymer content of 10 to 30% by mass, more preferably the second swelling resin. It is more preferable that the content of the water-absorbing polymer having water-swelling swelling is 1 to 7% by mass.

  In the curable paste-like urethane-based resin, as the water-absorbing polymer, any polymer having a water-absorbing swelling property can be used. For example, acrylic acid-based polymers, isobutylene / maleic acid-based polymers, polyvinyl alcohol A system polymer or the like can be used. As these water-absorbing polymers, commercially available products can be used. For example, as the acrylic acid-based polymer, those described in JP-A-2014-70271 can be used.

  The water-absorbing polymer preferably has a swelling ratio (weight ratio of water absorption of the sample after immersing the sample in 3.5% saline for 2 hours) in the range of 10 to 40 times, preferably 20 times. Those within the range of 30 to 30 times are more preferable.

  The urethane-based resin containing the water-absorbing polymer is in the form of a paste, preferably a one-component moisture-curable water-swellable urethane-based resin, and may also use a two-component curable urethane-based resin. As the one-component moisture-curable water-swellable urethane-based resin, for example, a polyurethane sealant containing an isocyanate group-containing prepolymer obtained by reacting a polyisocyanate and a polyether polyol as a main component can be used. As the one-component moisture-curable water-swellable urethane-based resin, for example, the one described in JP-A-2014-70271 can be used.

  Note that the transmission line 52 that has entered the connection box 12 is fixed by a fixing member 26 at a position immediately protruding from the protection tube 54. This is to prevent the tensile force transmitted from the outside through the transmission line 52 from acting on the sacrificial anode side connection portion 16 side and the steel member side connection portion 18 side. This fixing may be performed by fixing the detection component 14.

  The protection tube 54 is inserted into the resin connector 28 attached to the through hole provided in the leg 106A, and reaches the connection box 12, and the end of the protection tube 54 on the connection box 12 side is: It is fixed by a resin connector 28.

  The position where the resin connector 28 is attached is not limited to the illustrated position. For example, the resin connector 28 may be attached to the lower surface of the connection box 12.

  As described above, the anticorrosion current detector 10 according to the present embodiment includes the connection box 12, in which the detection component 14, the sacrificial anode side connection part 16, the steel member side connection part 18, and the transmission The wiring boxes 20 and 22 are housed therein, and the connection box 12 is filled with a swelling resin 24. The detection components 14 housed in the connection box 12 and the sacrificial anode-side connection sections 16 The steel member side connection portion 18 and the transmission line side connection portions 20 and 22 are covered with a swelling resin 24. Specifically, as described above, the detection component 14, the sacrificial anode-side connection portion 16, the steel member-side connection portion 18, and the transmission line-side connection portions 20 and 22 housed in the connection box 12 are formed of the swelling resin 24. And is covered with the swelling resin 24 with water removed. For this reason, the detection component 14, the sacrificial anode side connection part 16, the steel member side connection part 18, and the transmission line side connection parts 20 and 22 are filled with the filled swelling resin 24 in the connection box 12 without gaps. Since it is housed in the connection box 12, moisture is removed by the swelling resin 24, and the anticorrosion property is maintained. In addition, since the swelling resin 24 is in close contact with and covers the swelling resin 24, it is possible to prevent external force due to collision of waves and drifting substances, and invasion, adhesion and growth of marine organisms.

  Further, as described above, if the swelling resin made of the curable paste-like urethane-based resin containing the water-absorbing polymer is used as the swelling resin 24, the detection component 14 and the connection portions 16 and 18 housed in the connection box 12 are used. , 20, 22 and the like are filled in the gap with high followability, and the flexibility can be maintained for a long period of time. Since the flexibility can be maintained for a long period of time, the connection box can be easily removed even when the transmission line 52 and the detection component 14 whose service life is shorter than those of the cathodic protection target equipment and the sacrificial anode 80 are replaced. The swelling resin 24 filled in the inside 12 does not hinder the replacement work of the transmission line 52 and the detection component 14.

  It is not necessary to use the same material as the swelling resin 24 that can maintain flexibility as described above around components that do not need to be replaced. A resin having a higher hardness at the time of curing may be partially used around parts that do not need to be replaced.

  In addition, since the swelling resin 24 can fill the inside of the connection box 12 without gaps, the growth of marine organisms can be suppressed, and damage to components such as the transmission line 52 and damage to the connection portions 16, 18, 20, and 22 can be prevented. It is possible to prevent a problem that the fitting is not performed and the lid 12A of the connection box 12 is not removed.

  Further, since one-touch terminals are used in the sacrificial anode-side connection portion 16, the steel member-side connection portion 18, and the transmission line-side connection portions 20 and 22, the workability of replacing the transmission line 52 and the detection component 14 is improved. Is better.

  In FIG. 1, an area 108 indicated by hatching is an area in which coating protection is performed, and is an area centered on the ebb and splash zone.

(2) Configuration and Effect of Reference Electrode Device 30 FIG. 7 is a front view showing a state where the reference electrode device 30 according to the embodiment of the present invention is attached to the leg 106A of the jacket 106, and FIG. 9 is an enlarged front view showing a portion of the reference electrode device 30 of FIG. 8 in an enlarged manner, and FIG. 9 is an enlarged front view showing a portion of the reference electrode device 30 of FIG. 7 to 9, each component in the connection box 32 of the collation electrode device 30 is described by a solid line instead of a broken line (hidden line).

  The collation electrode device 30 according to the present embodiment includes a connection box 32, a collation electrode 34, a transmission line side connection portion 36, and a swelling resin 38.

  The connection box 32 is a box-shaped steel member, and is attached to a predetermined position on the outer peripheral surface of the leg 106A by welding. The connection box 32 has therein the reference electrode 34 other than the electrode portion 34A and the transmission electrode 34A. The wire side connection part 36 is housed. Further, the connection box 32 is filled with a swelling resin 38, and the reference electrode 34 housed in the connection box 32 is made of the swelling resin 38 except for a portion in contact with the electrode portion 34 </ b> A and the inner surface of the connection box 32. The transmission line side connection portion 36 is entirely covered with a swelling resin 38.

  The connection box 32 is provided with a lid 32A, and can be opened when the transmission line 62 or the reference electrode 34 is replaced.

  The reference electrode 34 is an electrode that gives a reference point of the potential when measuring the potential at a predetermined position of the jacket 106. The electrode portion 34A of the reference electrode 34 is located so as to protrude outside the connection box 32, and is immersed in seawater. The reference electrode terminal 34B of the reference electrode 34 is housed in the connection box 32, is connected to the terminal 62A of the transmission line 62 at the transmission line side connection portion 36, and is electrically connected.

  The type of the reference electrode that can be used as the reference electrode 34 is not particularly limited, and specifically, for example, a zinc reference electrode can be used.

  The transmission line side connection portion 36 is a connection portion that electrically connects the verification electrode terminal 34B of the verification electrode 34 and the terminal 62A of the transmission line 62. In the transmission line side connection portion 36, a one-touch terminal is used, and the one-touch terminal is a pair of terminals including a male terminal and a female terminal. The male terminal and the female terminal are fitted together and pushed in the direction of fitting, whereby the male terminal and the female terminal are fitted, and the verification electrode terminal 34B and the terminal 62A can be easily connected. It can be electrically connected. Therefore, in the transmission line side connection part 36, even underwater work can be easily connected.

  The one-touch type terminal used in the transmission line side connection portion 36 has a cover (not shown) for further covering the connection portion from outside. As such a one-touch type terminal, for example, a product of the TH387 series manufactured by Techno s.r.l. of Italy can be used.

  The swelling resin 38 is a resin that expands by absorbing moisture. The swelling resin 38 is excellent in shape followability, and when the swelling resin 38 is filled in the connection box 32, the transmission line side connection portion 36 accommodated in the connection box 32 is entirely adhered by the swelling resin 38. And is covered with the swelling resin 38 in a state where moisture is removed. Therefore, when the connection box 32 is filled with the swelling resin 38, the transmission line side connection portion 36 is maintained in a state where the anticorrosion property is maintained. In addition, the reference electrode 34 housed in the connection box 32 is covered with the swelling resin 38 in a state where moisture is excluded, except for a portion in contact with the electrode portion 34A and the inner surface of the connection box 32, so that the anticorrosion property is improved. It is kept in the state.

  In addition, the swelling resin 38 can maintain flexibility for a long period of time, and can be easily removed when the transmission line 62 or the reference electrode 34 is replaced.

  The swelling resin that can be used as the swelling resin 38 filling the connection box 32 of the collation electrode device 30 according to the present embodiment is the same as the swelling resin 24 filling the connection box 12 of the anticorrosion current detector 10. Other detailed description of the resin 38 will be replaced with the description of the swelling resin 24 described above.

  Note that the transmission line 62 that has entered the connection box 32 is fixed by a fixing member 40 at a portion immediately protruding from the protection tube 64. This is to prevent the tensile force transmitted from the outside through the transmission line 62 from acting on the reference electrode 34 side.

  The protection tube 64 extends through the resin connector 42 attached to the through hole provided in the leg 106A and reaches the connection box 32. The end of the protection tube 64 on the connection box 32 side is It is fixed by a resin connector 42.

  As described above, the reference electrode device 30 according to the present embodiment includes the connection box 32, and the connection box 32 includes therein the reference electrode 34 other than the electrode unit 34A and the transmission line side connection unit 36. It is stored. The connection box 32 is filled with a swelling resin 38, and the transmission line side connection portion 36 housed in the connection box 32 is entirely covered with the swelling resin 38 in close contact with the swelling resin 38. Are covered with the swelling resin 38 in a state in which is removed. For this reason, since the transmission line side connection portion 36 is housed in the connection box 32 in a state where the inside of the connection box 32 is filled with the filled swelling resin 38 without any gap, the swelling resin 38 removes moisture. Thus, the anticorrosion property is maintained. The reference electrode 34 accommodated in the connection box 32 has a state in which the connection box 32 is completely filled with the swelling resin 38 except for a portion in contact with the electrode portion 34A and the inner surface of the connection box 32. Since it is housed in the connection box 32, moisture is eliminated by the swelling resin 38, and the anticorrosion property is maintained. In addition, since the swelling resin 38 is in close contact with and covers the swelling resin 38, it is possible to prevent external forces due to collision of waves and drifting substances, and invasion, adhesion and growth of marine organisms.

  Further, as described above, when the swelling resin made of the curable paste-like urethane-based resin containing the water-absorbing polymer is used as the swelling resin 38, the transmission line side connection portion 36 housed in the connection box 32 and the reference electrode The gap is filled with a high followability even for a complicated shape formed by 34 or the like, and flexibility can be maintained for a long time. Since the flexibility can be maintained for a long time, the connection box can be easily removed even when the transmission line 62 or the reference electrode 34 whose service life is shorter than that of the cathodic protection target equipment or the sacrificial anode 80 is replaced. The swelling resin 38 filled in the inside 32 does not hinder the exchange work of the transmission line 62 and the reference electrode 34.

  In addition, since the swelling resin 38 can fill the inside of the connection box 32 without gaps, it can suppress the growth of marine organisms, breakage of components such as the transmission line 62, and disengagement of the transmission line side connection portion 36. In addition, it is possible to prevent a problem that the lid 32A of the connection box 32 does not come off.

  Further, since the one-touch type terminal is used in the transmission line side connection portion 36, the workability of replacing the transmission line 62 and the reference electrode 34 is further improved.

(3) Configuration and Effect of Cathodic Protection Monitoring Device 50 for Corrosion Protection Current Measurement FIG. 10 schematically shows a state in which the cathodic protection monitoring device 50 for corrosion protection current measurement according to the embodiment of the present invention is applied to a jacket-type pier 100. 11 is an end view taken along line XI-XI in FIG. 10, and FIG. 12 is an enlarged end view showing an XII portion in FIG. FIG. 13 is an enlarged vertical cross-sectional view (an enlarged vertical cross-sectional view cut along a vertical plane parallel to the longitudinal direction of the steel girder 106B) showing an enlarged upper end portion of the leg 106A to which the anticorrosion current detector 10 is attached. FIG. 14 is an enlarged front view of steel girder 106B viewed from a horizontal direction orthogonal to the longitudinal direction, and FIG. 15 is an end view taken along line XV-XV of FIG. In FIG. 10, the land side portion of the jacket 106 is not shown.

  An anticorrosion monitoring device 50 for measuring anticorrosion current according to the present embodiment includes the anticorrosion current detector 10, a transmission line 52, and a monitoring unit 58.

  The anticorrosion current detector 10 is the anticorrosion current detector according to the embodiment of the present invention described above, and is attached to the leg 106A on the sea side of the jacket 106.

  The transmission line 52 is a transmission line that sends an electric signal about the anticorrosion current detected by the anticorrosion current detector 10 to the monitoring unit 58. The transmission line 52 is a two-core transmission line, and the terminals 20B and 22B of the anticorrosion current detector 10 are connected to the transmission line side connection portions 20 and 22 of the anticorrosion current detector 10, respectively. An electric signal from the detection component 14 is transmitted to the monitoring unit 58.

  The transmission line 52 is covered and protected by a protection tube 54, and is disposed inside the protection tube 54 (see FIGS. 5 and 12 and the like). In the superstructure part of the jacket 106, the protective tube 54 provided with the transmission line 52 is fastened with fasteners 56 at appropriate intervals and arranged along the steel girder 106B of the jacket 106 (FIG. 1). , FIG. 10, FIG. 14, FIG. 15, etc.), the transmission line 52 reaches the monitoring unit 58. On the other hand, the attachment portion of the protection tube 54 having the transmission line 52 therein to the leg 106A is the inner peripheral surface of the leg 106A, and the transmission line 52 is disposed inside the leg 106A of the jacket 106 together with the protection tube 54. (See FIG. 5, FIG. 12, etc.). Also, as shown in FIGS. 11 and 12, an angle 55 is attached to the inner peripheral surface of the leg 106A, and the protection tube 54 having the transmission line 52 therein is provided with the angle 55 and the inner peripheral surface of the leg 106A. It is arranged in a space surrounded by faces.

  In a region where the steel pipe pile 104 is inserted into the leg 106A of the jacket 106 to form a double pipe structure, the transmission line 52, the protection pipe 54, and the angle 55 are formed between the inner peripheral surface of the leg 106A and the steel pipe pile 104. It is arranged in the gap between the outer peripheral surface.

  The monitoring unit 58 measures the electric signal of the anticorrosion current transmitted from the transmission line 52, calculates the magnitude of the anticorrosion current, and stores the data in a storage unit (not shown). The monitoring unit 58 displays the stored data on a monitor (not shown) in a graph or the like as necessary.

  The transmission line 52 is disposed inside the protection tube 54 and is protected by being covered with the protection tube 54. Further, the attachment part of the protection tube 54 provided with the transmission line 52 to the leg 106A is a leg 106A. The transmission line 52 is disposed in the inner space of the leg 106A of the jacket 106 together with the protective tube 54 at a position below the sea level, so that the transmission line 52 is generated by an external force such as a wave or a drifting object. The possibility of physical damage to 52 is very small.

(4) Configuration and Effect of Cathodic Protection Monitoring Device 60 for Potential Measurement FIG. 16 schematically shows a state in which the cathodic protection monitoring device 60 for potential measurement according to the embodiment of the present invention is applied to the jacket-type pier 100. 17 is an end view taken along the line XVII-XVII of FIG. 16, and FIG. 18 is an enlarged end view showing an XVIII portion of FIG. FIG. 19 is an enlarged vertical cross-sectional view (an enlarged vertical cross-sectional view cut along a vertical plane parallel to the longitudinal direction of steel girder 106B) showing an enlarged upper end portion of leg 106A to which reference electrode device 30 is attached. FIG. 20 is an enlarged front view of steel girder 106B viewed from a horizontal direction orthogonal to the longitudinal direction, and FIG. 21 is an end view taken along line XXI-XXI of FIG. In FIG. 16, the illustration of the land side portion of the jacket 106 is omitted.

  The anticorrosion monitoring device 60 for potential measurement according to the present embodiment includes the reference electrode device 30, the transmission line 62, and the monitoring unit 68.

  The reference electrode device 30 is the reference electrode device according to the embodiment of the present invention described above, and is attached to the leg 106A on the sea side of the jacket 106.

  The transmission line 62 is a transmission line that sends an electric signal about the potential from the reference electrode device 30 to the monitoring unit 68. The transmission line 62 is a single-core transmission line, and a terminal 62 </ b> A on the reference electrode device 30 side is connected to the transmission line side connection portion 36 of the reference electrode device 30. The signal is transmitted to the monitoring unit 68.

  The transmission line 62 is covered and protected by a protection tube 64, and is disposed inside the protection tube 64 (see FIGS. 9 and 18 and the like). In the superstructure part of the jacket 106, the protection tube 64 provided with the transmission line 62 is fastened with fasteners 66 at appropriate intervals and arranged along the steel girder 106B of the jacket 106 (FIG. 1). , FIG. 16, FIG. 20, FIG. 21, etc.), and the transmission line 62 reaches the monitoring unit 68. On the other hand, the attachment portion of the protection tube 64 provided with the transmission line 62 to the leg 106A is the inner peripheral surface of the leg 106A, and the transmission line 62 is disposed inside the leg 106A of the jacket 106 together with the protection tube 64. (See FIG. 9, FIG. 18, etc.). As shown in FIGS. 17 and 18, an angle 65 is attached to the inner peripheral surface of the leg 106A, and the protection tube 64 having the transmission line 62 inside is formed by the angle 65 and the inner peripheral surface of the leg 106A. It is arranged in a space surrounded by faces.

  In a region where the steel pipe pile 104 is inserted into the leg 106A of the jacket 106 to form a double pipe structure, the transmission line 62, the protection pipe 64, and the angle 65 are formed between the inner peripheral surface of the leg 106A and the steel pipe pile 104. It is arranged in the gap between the outer peripheral surface.

  The monitoring unit 68 measures the electric signal of the electric potential transmitted from the transmission line 62, calculates the electric potential of a predetermined portion of the jacket-type pier 100, and stores the data in a storage unit (not shown). Further, the monitoring unit 68 displays the stored data on a monitor (not shown) in a graph or the like as necessary.

  The transmission line 62 is disposed inside the protection tube 64 and is covered and protected by the protection tube 64. Further, the attachment portion of the protection tube 64 provided with the transmission line 62 to the leg 106A is a leg 106A. Since the transmission line 62 is disposed inside the leg 106A of the jacket 106 together with the protective tube 64 at a position below the sea level, the transmission line 62 is transmitted to the transmission line 62 by an external force such as a wave or a drifting object. The potential for physical damage is extremely small.

(5) Supplement As described above, the embodiments of the present invention have been described with reference to the drawings. However, the drawings used for the description schematically show the embodiments for describing the present invention, and the present invention However, the present invention is not limited to the configuration shown in the drawings used in the description, and various changes can be made in the present invention without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Corrosion prevention current detector 12, 32 ... Connection box 12A, 32A ... Lid 12B, 12D, 86D, 86F ... Insulation plate 12C, 86E ... Insulation sleeve 14 ... Detection component 14A ... One end 14B ... Other end 16 ... Sacrificial anode side connection Part 16A, 16B, 18A, 18B, 20A, 20B, 22A, 22B, 34B, 62A ... Terminal 18 ... Steel member side connection part 20, 22, 36 ... Transmission line side connection part 24, 38 ... Swelling resin 26, 40 ... Fixing members 28, 42 ... resin connector 30 ... reference electrode device 34 ... reference electrode 34A ... electrode part 50, 60 ... cathodic protection monitoring device 52, 62 ... transmission line 54, 64 ... protective tube 55, 65 ... angle 56, 66 ... Fasteners 58, 68 ... Monitoring part 80 ... Sacrificial anodes 82, 84 ... Cores 82A, 82B, 84A, 86C ... Bolts 83A, 3B ... connection fitting 86 ... insulating connecting portion 86A ... insulator 86B ... Mizokatachiko 100 ... jacketed pier 102 ... Seabed 104 ... pipe pile 106 ... jacket 106A ... leg 106B ... steel girder 108 ... coating anticorrosive 200 ... quay

Claims (17)

An anticorrosion current detector attached to a structure having a steel member below the water surface and used for measuring an anticorrosion current flowing between the sacrificial anode and the steel member,
One end is electrically connected to the sacrificial anode, the other end is electrically connected to the steel member, and a detection component for detecting the anticorrosion current,
A sacrificial anode-side connection portion formed by electrically connecting a terminal electrically connected to the sacrificial anode and a terminal electrically connected to one end of the detection component,
A steel member-side connection portion formed by electrically connecting a terminal electrically connected to the steel member and a terminal electrically connected to the other end of the detection component,
A transmission line side connection in which one end of an external device connection transmission line that can be electrically connected to an external device is electrically connected to an output terminal that outputs an electric signal about the anticorrosion current obtained by the detection component to the outside. Department and
A connection box that houses the detection component, the sacrificial anode-side connection portion, the steel member-side connection portion, and the transmission line-side connection portion,
With
The inside of the connection box is filled with a swelling resin that swells by absorbing moisture, and the detection component, the sacrificial anode side connection portion, the steel member side connection portion, and the transmission line side connection portion include the swelling resin. An anticorrosion current detector, characterized by being covered by the anticorrosion current detector.   2. The anticorrosion current detector according to claim 1, wherein the swelling resin is composed of two kinds of swelling resins having different water-swelling swelling properties.   The two types of swelling resins having different water-swelling swelling properties include a curable paste urethane resin having a water-absorbing polymer content of 5 to 40% by mass, and a water-absorbing swelling property having a water-absorbing swelling property. 3. The anticorrosion current detector according to claim 2, wherein the curable paste urethane-based resin has a molecular content of 0 to 10% by mass.   In at least one of the sacrificial anode-side connection portion, the steel member-side connection portion and the transmission line-side connection portion, a pair of terminals including a male terminal and a female terminal is used, and the male terminal The terminal and the female terminal are fitted together and pushed in the direction of fitting, whereby the male terminal and the female terminal can be fitted and electrically connected to each other. 3. The anticorrosion current detector according to any one of 3.   The anticorrosion current detector according to claim 4, wherein the sacrificial anode side connection part, the steel member side connection part, and the transmission line side connection part are covered with a cover on the outside. A reference electrode device attached to a structure having a steel member below the water surface, and used for measuring potential data on the steel member,
A reference electrode;
An output terminal that outputs the potential data of the reference electrode to the outside, a transmission line-side connection portion formed by electrically connecting one end of an external device connection transmission line that can be electrically connected to an external device,
A connection box for housing the transmission line side connection portion,
With
A swelling resin is filled in the inside of the connection box, and the transmission-line-side connection portion is covered with the swelling resin.   7. The reference electrode device according to claim 6, wherein the swelling resin is made of two kinds of swelling resins having different water-swelling swelling properties.   The two types of swelling resins having different water-swelling swelling properties include a curable paste urethane resin having a water-absorbing polymer content of 5 to 40% by mass, and a water-absorbing swelling property having a water-absorbing swelling property. The reference electrode device according to claim 7, wherein the paste is a curable paste-like urethane resin having a molecular content of 0 to 10% by mass.   In the transmission line-side connection portion, a pair of terminals consisting of a male terminal and a female terminal is used, and by fitting the male terminal and the female terminal, by pushing in the direction of fitting, The verification electrode device according to any one of claims 6 to 8, wherein the male terminal and the female terminal can be fitted and electrically connected.   The reference electrode device according to claim 9, wherein an outer side of the transmission line side connection portion is covered with a cover. A cathodic protection monitoring device used for cathodic protection of a structure having a steel member below the water surface,
An anticorrosion current detector according to any one of claims 1 to 5,
A monitoring unit that receives an electric signal about the anticorrosion current from the anticorrosion current detector, measures data on the anticorrosion current, and performs at least one of recording and displaying data on the measured anticorrosion current. When,
A monitoring unit connection transmission line for transmitting an electric signal about the anticorrosion current to the monitoring unit,
With
The anticorrosion current detector is attached to the structure, and the external device connection transmission line is the monitoring unit connection transmission line, and one end of the monitoring unit connection transmission line is connected to the corrosion prevention current detector. It is electrically connected to the output terminal, forms the transmission line side connection portion, and the other end of the monitoring unit connection transmission line is electrically connected to the monitoring unit. Cathodic protection monitoring device. A cathodic protection monitoring device used for cathodic protection of a structure having a steel member below the water surface,
A reference electrode device according to any one of claims 6 to 10,
Receiving an electric signal about the potential difference between the reference electrode and the steel member, measuring data on the potential of the steel member, and recording and displaying at least data on the measured potential of the steel member. A monitoring unit that does one side,
A monitoring unit connection transmission line that transmits an electric signal from the reference electrode device to the monitoring unit,
With
The reference electrode device is attached to the structure, and the external device connection transmission line is the monitoring unit connection transmission line, and one end of the monitoring unit connection transmission line is connected to the output of the verification electrode device. A terminal electrically connected to a terminal to form the transmission line side connection portion, and the other end of the monitoring unit connection transmission line is electrically connected to the monitoring unit. Monitoring device.   The cathodic protection monitoring device according to claim 11, wherein the structure is a jacket.   The cathodic protection monitoring device according to claim 13, wherein the monitoring unit connection transmission line reaches the transmission line side connection unit via the inside of a steel pipe forming the jacket.   A jacket to which the anticorrosion current detector according to any one of claims 1 to 5 is attached, wherein a portion to which the anticorrosion current detector is attached exists in water.   A jacket to which the reference electrode device according to any one of claims 6 to 10 is attached, wherein a portion where the reference electrode device is attached is in water.   A jacket to which the anticorrosion current detector according to any one of claims 1 to 5 and the reference electrode device according to any one of claims 6 to 10 are attached, and a portion to which the anticorrosion current detector is attached and A jacket to which the reference electrode device is attached is underwater.