Sensing moisture or corrosion

Abstract

An elongate sensor (1), system and method for detecting moisture and / or corrosion are presented. The elongate sensor 1 may comprise a plurality of conductors (3, 4, 5, 6) positioned alongside or parallel to each other, not in contact with each other, and not in direct electrical contact with each other. Each of the conductors has a different pattern of alternating insulated and non-insulated portions. In each insulating portion, the Nth conductor is within the non-conductive material to form an Nth non-detection portion (24). In each non-insulating portion, the Nth conductor is exposed or is not electrically insulated to form an Nth detection portion. Each of the Nth detection portion or the non-detection portion will have a single Nth unit length. Each Nth unit length is equal to the first unit length which is N minus one power of two, namely the distance which is 2 (N-1) times of the first unit length. The conductive object provides a base conductor and / or the elongated sensor includes a base conductor.

Description

Technical Field

[0001] The present invention relates to sensing moisture and corrosion, and in particular to sensors, monitoring units and systems. Background Art

[0002] There are many situations where it is necessary to sense the location of moisture, and there are many different types of sensors and systems known that detect the location of moisture.

[0003] For example, detecting corrosion of pipelines surrounded by insulating or fireproof materials is currently accomplished by using probes to look for moisture at various points along the pipeline or pipeline, or by using sacrificial wires that corrode due to the presence of moisture or other corrosive environments. These methods have significant disadvantages. For example, using probes that inherently can only detect moisture in a small area adjacent to each probe test site can only provide results for a local area, rather than for the entire length of the pipeline. If the test is conducted away from the moisture point or away from the corrosion point, the test results will be misleading.

[0004] Arrangements using local test probes are disclosed in, for example, U.S. Pat. No. 4,703,254 using permanently fixed probes spaced apart along the pipeline and U.S. Pat. No. 5,243,297 using parallel sacrificial and guard wires in the probes to detect corrosion conditions at the location of each probe. In contrast, sacrificial wire type arrangements such as those described in U.S. Pat. Nos. 4,338,563 or 5,036,287 may indicate that a problem exists somewhere along the length of the pipeline, but not where along that length the problem may exist.

[0005] To overcome these disadvantages, it is known to generate an electromagnetic waveform, pass the electromagnetic waveform along an electromagnetic waveguide adjacent to the pipeline, and then analyze the reflected portion of the waveform, such as in U.S. Pat. No. 10,809,217. The waveguide includes a sacrificial portion, and analysis of the reflected waveform enables the location of corrosion of the sacrificial portion of the waveguide to be determined. It is said that given adequate signal processing, corrosion is detected when located at one location or when located at multiple locations.

[0006] Electromagnetic field sensors may be used to characterize the material condition of an object such as a pipe. As disclosed in US Pat. No. 10,324,062, the sensor and associated data processing system, once calibrated, may detect features such as the size of a crack or corrosion when stimulated by a signal generator.

[0007] Another known form of moisture detection is disclosed in U.S. Patent Nos. 9,719,951 and 11,313,757. These arrangements utilize at least three conductors in parallel, wherein one of the conductors has a resistance different from that of the other conductors. When liquid extends between the conductors, then the difference between the impedance first through one pair of conductors and the liquid and second through another pair of conductors and the liquid can be used to determine the position of the liquid along the length of the conductors. A similar method can be used to determine the area of ​​the liquid relative to the conductors.

[0008] None of the known solutions provide a reliable and accurate solution to the problem of identifying moisture or corrosion. In the case of waveform arrangements, they require complex equipment and can be affected by external changes in the environment such as proximity to pipes or other objects. In the case of resistance methods, large variations in moisture conductivity present a significant obstacle and it is not possible to distinguish the location of more than one moisture event or to delineate between a single moisture location and multiple moisture locations.

[0009] It should be understood that if any prior art is referred to herein, this reference does not constitute an admission that the prior art forms part of the common general knowledge in the art in Australia or any other country. Summary of the invention

[0010] According to a first aspect of the present invention, there is provided an elongated sensor for a system for detecting moisture and / or corrosion, the elongated sensor comprising at least a first conductor, a second conductor and a third conductor, each of the at least first, second and third conductors being positioned parallel to each other by a non-conductive carrier material to prevent the conductors from coming into direct conductive contact with each other or with an external conductive surface while allowing a conductive medium to enter; the first conductor being exposed or non-electrically insulated for a first unit length to form an initial first detection portion and then alternately electrically insulated for a distance equal to the first unit length to form a first non-detection portion or non-electrically insulated for a distance equal to the first unit length to form an additional first detection portion of the first conductor; the second conductor being electrically insulated The second conductor is electrically insulated for a distance equal to the second unit length minus the first unit length to form an initial second non-detection portion, and then alternately electrically non-insulated for a distance equal to the second unit length to form a second detection portion, or electrically insulated for a distance equal to the second unit length to form an additional second non-detection portion of the second conductor, the second unit length being twice the first unit length; the third conductor is electrically insulated for a distance equal to the third unit length minus the first unit length to form an initial third non-detection portion, and then alternately electrically non-insulated for a distance equal to the third unit length to form a third detection portion, or electrically insulated for a distance equal to the third unit length to form a non-detection portion of the third conductor, the third unit length being twice the second unit length.

[0011] The conductive medium may be, for example, a conductive fluid such as water, or water and conductive particles such as small rust particles.

[0012] Preferably, the elongate sensor may have a length greater than the third unit length.

[0013] At least the first conductor, the second conductor, and the third conductor may further include a base conductor; the base conductor is exposed or uninsulated and positioned parallel to the first, second, and third conductors by a non-conductive material. The non-conductive material can physically position the conductors substantially in parallel, or at least hold the conductors closely together, while preventing the base conductor from coming into direct conductive contact with any of the at least first, second, and third conductors and optionally also with any external conductive surface such as an adjacent metal surface, while allowing the conductive medium to enter the base conductor.

[0014] Unlike the base conductor, the first, second, and third conductors may be alternating portion conductors in that they each have alternating non-sensing portions and sensing portions.

[0015] The base conductor may be corrodible. Additionally or alternatively, the base conductor may include a plurality of parallel uninsulated conductors, some of which may differ in size and / or corrosivity. For example, the base conductor or one of the base conductors may be corrosion resistant.

[0016] At least one of the first conductor, the second conductor and the third conductor may be corrosion resistant. For example, at least one of the conductors may be stainless steel.

[0017] At least one of the first conductor, the second conductor, and the third conductor may further include a resistor connected in series with the respective conductor. The resistor used for one of the conductors may be different from the resistor of another of the conductors, or each conductor may utilize a resistor of a different value. Alternatively or additionally, at least two of the first conductor, the second conductor, and the third conductor may have different resistances. For example, the first conductor may be made of a different material than the second conductor or have a different cross-section than the second conductor.

[0018] Alternatively, at least at least one of the first, second and third conductors further comprises at least two resistors connected in series with the respective conductor and equidistantly distributed along the respective conductor. For example, two sets of elongated sensors connected in series may comprise a first elongated sensor, a second elongated sensor and a third elongated sensor, each having a respective first resistor between one of each of the conductors of the first elongated sensor and a respective conductor of the second elongated sensor, and a respective second resistor between one of each of the conductors of the second elongated sensor and a respective conductor of the third elongated sensor. Alternatively, the conductor of the first elongated sensor may have a different resistance than the conductor of the second elongated sensor by utilizing different materials or different cross-sectional areas. Similarly, any additional elongated sensor may have a conductor with a different resistance than the other elongated sensors.

[0019] The first unit length may be at most and include 1 meter, preferably at most and include 2 meters, or more preferably at most and include 4 meters. Alternatively, the first unit length may be greater than 4 meters.

[0020] The elongated sensor may be held, adhered or fixed beneath a substantially horizontal object and / or hover around a substantially vertical object. For example, a set of at least two elongated sensors may hover around an object. The set of two hovering sensors may, for example, be parallel to each other, such as on opposite sides of any given cross-section of the object, or may alternatively be cross-sectional to each other.

[0021] The elongated sensor may include a fourth conductor that is electrically insulated a distance equal to the fourth unit length minus the first unit length to form an initial fourth non-detecting portion and then alternately electrically non-insulated a distance equal to the fourth unit length to form a fourth detecting portion, or electrically insulated a distance equal to the fourth unit length to form a fourth non-detecting portion of the fourth conductor, the fourth unit length being twice the third unit length. An alternative definition of the fourth unit length is that it may be eight times the first unit length, or another alternative definition is that it may be twice the first unit length. (4-1) Preferably, the elongated sensor may have a length greater than the fourth unit length.

[0022] The elongated sensor may include an Nth conductor that is electrically insulated a distance equal to the Nth unit length minus the first unit length to form an initial Nth non-sensing portion and then alternately electrically non-insulated a distance equal to the Nth unit length to form an Nth sensing portion, or electrically insulated a distance equal to the Nth unit length to form an Nth non-sensing portion of the Nth conductor, the Nth unit length being twice the first unit length. (N-1) Preferably, the elongated sensor may have a length greater than the Nth unit length.

[0023] The non-conductive carrier material and the conductors may be woven together. This may help position the conductors closely together while still preventing the conductors from coming into direct electrical contact with each other or with external conductive surfaces.

[0024] Alternatively, the non-conductive carrier material may be a strip or tape to which the conductor is secured, such as adhered or printed. If the conductor is printed onto a non-conductive carrier, the non-detecting portion may be printed with non-conductive material in appropriate portions on the conductor.

[0025] The elongated sensor may include a detector unit electrically connected to each conductor. The detector unit may detect conductivity between the conductors. Alternatively or additionally, the detector unit may measure resistance, impedance and / or capacitance between the conductors. The detector unit may be electrically connected to one end of each conductor or both ends of each conductor. The detector unit may include an input for connecting to an object to serve as at least a portion of the base conductor for the object. The detector unit may include an output. The output may be wired and / or wireless. The output may optionally include a visual indicator.

[0026] Another aspect of the present invention provides an elongated sensor for a system for detecting moisture and / or corrosion of an object, the elongated sensor comprising at least a first conductor, a second conductor and a third conductor, each of at least the first, second and third conductors being positioned parallel to each other by a non-conductive carrier material to prevent the conductors from coming into direct conductive contact with each other or with an external conductive surface while allowing a conductive medium to enter; the first conductor being electrically insulated for a first unit length to form an initial first non-detection portion and then alternately being electrically non-insulated for a distance equal to the first unit length to form a first detection portion or electrically insulated for a distance equal to the first unit length to form an additional first non-detection portion of the first conductor; the second conductor being electrically insulated for a distance equal to the second unit length a distance to form an initial second non-detection portion, the second unit length being twice the first unit length, and then alternately being non-electrically insulated by a distance equal to the second unit length to form a second detection portion, or electrically insulated by a distance equal to the second unit length to form an additional second non-detection portion of the second conductor; a third conductor being electrically insulated by a distance equal to a third unit length, the third unit length being twice the second unit length to form an initial third non-detection portion, and then alternately being non-electrically insulated by a distance equal to the third unit length to form a third detection portion, or electrically insulated by a distance equal to the third unit length to form a non-detection portion of the third conductor; an elongated sensor having a sensing area starting at an end of the initial first non-detection portion.

[0027] The conductive medium may be, for example, a conductive fluid such as water or water and conductive particles such as small rust particles.

[0028] An alternative definition of the third unit length may be that it is four times the first unit length, or it may be that it is twice the first unit length. (3-1) Preferably, the elongated sensor may have a length greater than the third unit length, otherwise the third conductor would be insulated over the entire length of the elongated sensor.

[0029] The elongated sensor may further include a base conductor that is exposed or uninsulated and positioned parallel to the first, second and third conductors by a non-conductive material. Likewise, the non-conductive material also serves to prevent the base conductor from coming into direct conductive contact with at least any one of the first, second and third conductors and optionally also with any external conductive surface such as an adjacent metal surface.

[0030] The elongated sensor may include an Nth conductor electrically insulated by a distance equal to an Nth unit length to form an initial Nth non-detecting portion, the Nth unit length being twice the first unit length. (N-1) times, and then alternately non-electrically insulated by a distance equal to the Nth unit length to form the Nth detection portion, or electrically insulated by a distance equal to the Nth unit length to form the Nth non-detection portion of the Nth conductor. Preferably, the elongated sensor may have a length greater than the Nth unit length.

[0031] Another aspect of the present invention provides a system for detecting moisture and / or corrosion of an object, the system comprising at least one elongated sensor and a sensor monitoring unit: the elongated sensor comprises at least a first conductor, a second conductor and a third conductor, each of at least the first, second and third conductors being positioned parallel to each other by a non-conductive carrier material to prevent the conductors from coming into direct conductive contact with each other or with an external conductive surface while allowing a conductive medium to enter; the first conductor is exposed or non-electrically insulated for a first unit length to form an initial first detection portion, and then alternately electrically insulated for a distance equal to the first unit length to form a first non-detection portion, or non-electrically insulated for a distance equal to the first unit length to form an additional first detection portion of the first conductor; the second conductor is electrically insulated for a distance equal to the second unit length minus the first unit length to form a an initial second non-detection portion, then alternately being non-electrically insulated for a distance equal to a second unit length to form a second detection portion, or electrically insulated for a distance equal to the second unit length to form a non-detection portion of the second conductor, the second unit length being twice the first unit length; a third conductor being electrically insulated for a distance equal to the third unit length minus the first unit length to form an initial third non-detection portion, then alternately being non-electrically insulated for a distance equal to the third unit length to form a third detection portion, or electrically insulated for a distance equal to the third unit length to form a non-detection portion of the third conductor, the third unit length being twice the second unit length; a monitoring unit being individually connectable to each of at least the first, second and third conductors, and being configured to detect electrical connectivity or conductivity between any pair of at least the first, second and third conductors.

[0032] The conductive medium may be, for example, a conductive fluid such as water or water and conductive particles such as small rust particles. An alternative definition of the length of the initial second non-detecting portion may be one first unit length. Similarly, an alternative definition of the length of the initial third non-detecting portion may be that it is equal to the first unit length plus the second unit length. Similarly, an alternative definition of the third unit length may be that it may be four times the first unit length. Preferably, the elongated sensor may have a length greater than the third unit length.

[0033] Another aspect of the present invention provides a system for detecting moisture and / or corrosion of an object, the system comprising at least one elongated sensor and a monitoring unit: the elongated sensor comprises at least a first conductor, a second conductor and a third conductor, each of the at least first, second and third conductors being positioned parallel to each other by a non-conductive carrier material to prevent the conductors from coming into direct conductive contact with each other or with an external conductive surface while allowing a conductive medium to enter; the first conductor is exposed or non-electrically insulated for a first unit length to form an initial first detection portion, and then alternately electrically insulated for a distance equal to the first unit length to form a first non-detection portion, or non-electrically insulated for a distance equal to the first unit length to form an additional first detection portion of the first conductor; the second conductor is electrically insulated for a distance equal to the second unit length minus the first unit length to form an initial second a non-detection portion, then alternately electrically non-insulated for a distance equal to a second unit length to form a second detection portion, or electrically insulated for a distance equal to the second unit length to form a non-detection portion of the second conductor, the second unit length being twice the first unit length; the third conductor being electrically insulated for a distance equal to the third unit length minus the first unit length to form an initial third non-detection portion, then alternately electrically non-insulated for a distance equal to the third unit length to form a third detection portion, or electrically insulated for a distance equal to the third unit length to form a non-detection portion of the third conductor, the third unit length being twice the second unit length; the monitoring unit being directly or preferably indirectly connected individually to each of at least the first, second and third conductors in use, and being configured to detect conductivity between any pair of at least the first, second and third conductors.

[0034] The conductive medium may be, for example, a conductive fluid such as water or water and conductive particles such as small rust particles. An alternative definition of the length of the initial second non-detecting portion may be one first unit length. Similarly, an alternative definition of the length of the initial third non-detecting portion may be that it is equal to the first unit length plus the second unit length. Similarly, an alternative definition of the third unit length may be that it may be four times the first unit length. Preferably, the elongated sensor may have a length greater than the third unit length.

[0035] The monitoring unit may be indirectly connected to the conductors of the elongated sensor, in that the elongated sensor may comprise a detection unit which is directly connected to the conductors of the elongated sensor and provides binary and / or processed and converted data to the monitoring unit.

[0036] In use, the system may further comprise a base conductor, wherein the monitoring unit is configured to detect conductivity between any pair of conductors comprising the base conductor and at least the first, second and third conductors. The base conductor may be comprised in the elongated sensor. The base conductor may be non-insulated and may be positioned parallel to the at least first, second and third conductors by a non-conductive carrier material. Additionally, the base conductor may comprise a plurality of wires of different diameters and / or different materials. At least one, preferably each, of the plurality of wires of such a base conductor may be non-insulated. Additionally or alternatively, the base conductor may be or may comprise an object.

[0037] In use, the elongate sensor may hover around or remain adjacent to or against the underside of an object, the object being electrically conductive and forming or serving as the base conductor.The object may be a pipe, structure or equipment.

[0038] The monitoring unit and / or any detection unit may convert the detected electrical connectivity or conductivity between the base conductor and the at least first, second and third conductors into a decimal number of a first unit length or into a distance. Such electrical connectivity or conductivity between the conductors is an indication of corrosion or moisture at a distance corresponding to a location or area having a length of the first unit length and located at a multiple of the unit length indicated in binary or base two by the connectivity or lack of connectivity of the at least first, second and third conductors.

[0039] The monitoring unit and / or any detection unit may detect the resistance between individual pairs of conductors and may determine the location of at least one location or region of corrosion or moisture. The at least one location or region may be two or more locations or regions. The individual pairs of conductors may be selected from a base conductor and at least a first, second, and third conductor. The locations of a plurality of regions (or segments having a length of a first unit length) in which corrosion or moisture is present may be determined using a function of the relative resistance between pairs of at least the base conductor, the first, second, and third conductors.

[0040] The monitoring unit and / or detection unit of the elongated sensor may be connected to the first end and the second end of each of the conductors and may detect and compare the resistance, impedance and / or capacitance measured from the first end with the resistance, impedance and / or capacitance measured at the second end. This may provide a further improvement in the location of multiple moisture and / or corrosion areas on one elongated sensor.

[0041] The monitoring device may be directly connected to the conductor of the elongated sensor. Alternatively, the monitoring unit may be indirectly connected to the conductor of the elongated sensor, the elongated sensor comprising a detector unit, the monitoring unit being connected to the detector unit of the elongated sensor. The monitoring unit may be connected to the detector unit by a wired or wireless connection.

[0042] The monitoring unit may obtain readings from the elongated sensor at predetermined time intervals. For example, the monitoring unit may receive an output signal from the elongated sensor upon expiration of each predetermined time interval. Alternatively, the monitoring unit may measure connectivity, conductivity, resistance, impedance and / or capacitance between pairs of conductors of the elongated sensor upon expiration of each predetermined time period.

[0043] The monitoring unit may convert the detected electrical connectivity or conductivity between the conductor pair into a decimal number of a first unit length or into a distance. The electrical connectivity or conductivity between the conductor pair is an indication of corrosion or moisture at a distance corresponding to a location or area having a length of the first unit length and located at a number of unit lengths indicated in binary or base two by the connectivity or lack of connectivity of at least the first, second and third conductors.

[0044] The system may further comprise a base conductor. The base conductor may be at least one additional conductor in the elongated sensor. Alternatively or additionally, in use, the base conductor may be an object. The monitoring unit may be configured to measure resistance, impedance and / or capacitance between individual pairs of conductors comprising the base conductor and the first, second and third conductors.

[0045] The monitoring unit may convert the resistance between at least the first, second and third conductor pairs to determine the location of at least one location or region of corrosion or moisture. The at least one location or region of corrosion or moisture may be two or more locations or regions. The location may be determined to a region or segment having a length of a first unit length, the location of the or each region or segment being determined by a binary or base-two indication of the connectivity between the conductor pairs and / or the relative resistance, capacitance or impedance between the individual pairs of conductors.

[0046] The monitoring unit and / or detection unit of the elongate sensor may be connected to the first end and the second end of each of the conductors and may detect and compare the resistance, impedance and / or capacitance between the conductor pair measured from the first end with the resistance, impedance and / or capacitance between the respective pair of conductors measured at the second end. This may provide a further improvement in the location of multiple moisture and / or corrosion areas on one elongate sensor.

[0047] The monitoring unit may periodically measure conductivity and / or resistance, impedance and / or capacitance in at least one elongate sensor, the sensor monitoring unit recording or tracking the time period over which the detection portion detects moisture. Preferably, such recording or tracking of the frequency and average duration or duration trend of occurrences of, for example, the detection portion of the elongate sensor being detecting moisture may be used to identify corrosion risk at particular locations. The system may then identify locations with the highest risk. Repair priorities for locations may be set. Resistance, impedance and / or capacitance may be measured to identify corrosion risk, with conductivity being used to indicate a sharp increase in corrosion risk.

[0048] The at least one elongate sensor may comprise a plurality of elongate sensors on a plurality of monitored objects, the measured conductivity and / or resistance, impedance and / or capacitance from each sensor being transmitted to the monitoring unit. The measured data from each elongate sensor may be transmitted to the monitoring unit via a wired or wireless connection. Preferably, a risk rating may be performed for all identified moisture or potential corrosion areas on all monitored objects.

[0049] At least one elongated sensor may be placed under a covering on an object, such as between the object and the covering on the object. The object may be a pipe, pipeline, equipment or structure. The elongated sensor may preferably be placed to detect if moisture has entered under the covering so that potential problems can be corrected. The system may detect the amount of time the moisture has been present. The system may detect if any non-conductive protective coating on the object has been compromised, i.e., the coating has failed or is beginning to fail, such as anything from a pinhole upwards that compromises or renders ineffective the protective coating's efficacy.

[0050] The non-conductive coating may be, for example, a paint or an anti-corrosion coating, including a mechanical protective layer, a thermosetting plastic layer, or a fire-resistant coating. The elongated sensor may typically be underneath an object where moisture may collect, and may be placed above the coating, but inside the covering. However, where multiple layers of coating are used, the sensor may be located between the multiple layers of coating.

[0051] The covering may be, for example, an insulating material, a fireproof or mechanical protective layer, a thermosetting plastic layer, a fire-resistant material or a weighting layer.

[0052] Another aspect of the present invention provides a method for detecting moisture or corrosion on an object, the method comprising: providing an elongated sensor including at least first, second, third, fourth and fifth conductors, each conductor having alternating detection portions and non-detection portions, the length of each detection portion and each non-detection portion of the first conductor having a unit length, each Nth conductor having a detection portion length and a non-detection portion length that is 2(N-1) times the unit length, the conductors being positioned parallel to each other by a non-conductive carrier material or tape, preventing the conductors from making direct electrical contact with each other or the object while allowing a conductive medium to enter.

[0053] Providing the elongate sensor may comprise providing at least one base conductor, the or each base conductor being uninsulated but positioned parallel to one another and prevented from making direct electrical contact with one another whilst allowing ingress of the conductive medium.

[0054] Alternatively or additionally, providing the elongate sensor may comprise providing at least one external connector.The method may further comprise connecting the external connector to an object or to ground, the external connector forming part of an external base conductor forming the base conductor or part of the base conductor.

[0055] The method may further include mounting the elongated sensor adjacent to the object. For example, the elongated sensor may be mounted adjacent to the object and beneath a covering surrounding the object.

[0056] The method may further include monitoring connectivity between the base conductor and at least the first, second, third, fourth, and fifth conductors.

[0057] The method may further include determining the presence of moisture or corrosion on the object: if moisture or corrosion is not detected on the object, then repeating the monitoring of connectivity after a pause of a predetermined time period; if moisture or corrosion is detected on the object, then calculating and reporting the location of the moisture or corrosion on the object.

[0058] Alternatively, if moisture or corrosion is detected on the object, the method may include measuring the resistance, capacitance and / or impedance of any or each connection between the base conductor and at least the first, second, third, fourth and fifth conductors to calculate and report at least one location of said moisture or corrosion on the object.

[0059] Alternatively, once the elongated sensor is installed, the method may include measuring the resistance, capacitance and / or impedance between at least the first, second, third, fourth and fifth conductors; determining the presence of moisture or corrosion on the object: if moisture or corrosion is not detected on the object, then after a pause of a predetermined time period, repeating the measurement of the resistance, capacitance and / or impedance; if moisture or corrosion is detected on the object, then calculating and reporting at least one location of the moisture or corrosion on the object.

[0060] After calculating and reporting the localized moisture or corrosion on the object, the method may further include: pausing for a predetermined period of time; and then repeating the monitoring and / or measuring steps. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] One or more embodiments or examples of the present invention will be described below with reference to the accompanying drawings, in which:

[0062] Figure 1 is a schematic diagram of an elongated sensor according to one aspect of the present invention.

[0063] Figure 2 is a schematic diagram of an elongated sensor according to another aspect of the present invention.

[0064] Figure 3 for Figure 1 Schematic diagram of an elongated sensor having a resistivity R 1 a piece of moisture or corrosion.

[0065] Figure 4 for Figure 3 Schematic diagram of an elongated sensor having a resistivity R1 The first block of moisture or corrosion and resistivity is R 2 The second piece is moisture or corrosion.

[0066] Figure 5 for Figure 1 Schematic diagram of an elongated sensor having a resistivity R 1 The first piece is moisture or corrosion and the resistivity at different locations is R 2 The second piece is moisture or corrosion.

[0067] Figure 6 is a schematic diagram of an elongated sensor according to another aspect of the present invention.

[0068] Figure 7 is a flow chart of a method according to another aspect of the present invention. DETAILED DESCRIPTION

[0069] In the following detailed description, reference is made to the accompanying drawings which form a part of the detailed description. The illustrative embodiments described in the detailed description, depicted in the drawings, and defined in the claims are not intended to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented. It will be readily understood that the various aspects of the disclosure, as generally described herein and illustrated in the drawings, may be arranged, substituted, combined, separated, and designed in a variety of different configurations, all of which are contemplated in the present disclosure.

[0070] Initial reference Figure 1 , there is an elongated sensor 1. The elongated sensor 1 comprises a plurality of conductors 3, 4, 5, 6 positioned alongside each other or parallel to each other, such that the conductors are not in contact with each other and therefore are not in direct electrical contact with each other.

[0071] The first conductor 4 (i.e., the first of the alternating portion conductors) has alternating insulating and non-insulating portions. In each non-insulating portion, the first conductor 4 is exposed or non-electrically insulated to form a first detection portion 11. In each insulating portion, the first conductor 4 is enclosed or encased in a non-conductive material to form a first non-detection portion 12. Each of the first detection portion 11 or the non-detection portion 12 has a single first unit length.

[0072] Similarly, the second conductor 5 (i.e., the second one of the alternating portion conductors) has alternating insulating and non-insulating portions. In each insulating portion, the second conductor 5 is enclosed or enclosed in a non-conductive material to form a second non-detecting portion 15. In each non-insulating portion, the second conductor 5 is exposed or not electrically insulated to form a second detecting portion 14. Each of the second detecting portion 14 or the non-detecting portion 15 has a single second unit length. Each second unit length is a distance equal to two first unit lengths.

[0073] Similarly, the third conductor 6 (i.e., the third of the alternating portion conductors) has alternating insulating and non-insulating portions. In each insulating portion, the third conductor 6 is enclosed or enclosed in a non-conductive material to form a third non-detecting portion 18. In each non-insulating portion, the third conductor 6 is exposed or not electrically insulated to form a third detecting portion 17. Each of the third detecting portions 17 or non-detecting portions 18 has a single third unit length. Each third unit length is a distance equal to two second unit lengths or equal to four first unit lengths.

[0074] Similarly, the fourth conductor 7 (i.e., the fourth of the alternating portion conductors) has alternating insulating and non-insulating portions. In each insulating portion, the fourth conductor 7 is enclosed or enclosed in a non-conductive material to form a fourth non-detecting portion 21. In each non-insulating portion, the fourth conductor 6 is exposed or not electrically insulated to form a fourth detecting portion 20. Each of the fourth detecting portion 20 or the non-detecting portion 21 has a single fourth unit length. Each fourth unit length is a distance equal to two third unit lengths or equal to four second unit lengths or equal to eight first unit lengths.

[0075] Similarly, the fifth conductor 8 (i.e., the fifth of the alternating portion conductors) has alternating insulating and non-insulating portions. In each insulating portion, the fifth conductor 8 is enclosed or encased in a non-conductive material to form a fifth non-detecting portion 24. In each non-insulating portion, the fifth conductor 8 is exposed or not electrically insulated to form a fifth detecting portion 23. Each of the fifth detecting portion 23 or the non-detecting portion 24 has a single fifth unit length. Each fifth unit length is a distance equal to two fourth unit lengths or equal to four third unit lengths or equal to eight second unit lengths or equal to sixteen first unit lengths.

[0076] In this pattern, as additional conductors are added, the Nth conductor will have alternating insulated and non-insulated sections. In each insulated section, the Nth conductor will be enclosed or encased in a non-conductive material to form an Nth non-detecting section 24. In each non-insulated section, the Nth conductor will be exposed or not electrically insulated to form an Nth detecting section. Each of the Nth detecting sections or non-detecting sections will have a single Nth unit length. Each Nth unit length is equal to two to the power of N minus one of the first unit lengths, i.e., 2 times the first unit length. (N-1) times the distance.

[0077] The sensing area 26 of the elongated sensor 1 begins at the beginning of the initial first detection portion 11 on the first conductor 4. Prior to this, Figure 1 An initial or zero portion 27 is shown in which the first, second, third, fourth and fifth conductors are all insulated.

[0078] Thus, now considering only those portions of the conductors within the sensing region 26 of the elongated sensor, the first conductor 4 is initially non-insulated in an initial first sensing portion 10 having a length of one first unit length. Also in this case, the second conductor 5 is initially insulated from an initial second non-sensing portion 13 having a length of the second unit length minus the first unit length, which is equal to one first unit length. The third conductor 6 is initially insulated from an initial third non-sensing portion 16 having a length of the third unit length minus the first unit length, which is equal to three times the first unit length. The fourth conductor 7 is initially insulated from an initial fourth non-sensing portion 19 having a length of the fourth unit length minus the first unit length, which is equal to seven times the first unit length. The fifth conductor 8 is initially insulated from an initial fifth non-sensing portion 22 having a length of the fifth unit length minus the first unit length, which is equal to fifteen times the first unit length, measured from the start of the sensing region 26 of the elongated sensor. Similarly, the Nth conductor will have an initial Nth non-detecting portion with electrical insulation equal to the Nth unit length minus the first unit length, which is equal to two times N minus one times the first unit length minus one first unit length, that is, (2 (N-1) -1) times.

[0079] Each of the first, second, third, fourth, fifth through Nth conductors of the elongated sensor may be referred to as alternating portion conductors because each conductor has alternating sensing (or exposed or non-insulated) portions and non-sensing (or insulated) portions.

[0080] The elongated sensor may use a conductive object as a base conductor, and / or the base conductor 3 may be provided as part of the elongated sensor, e.g. Figure 1 When provided as part of an elongated sensor, the base conductor 3 is exposed or not electrically insulated, but remains close to other conductors (such as first, second, third, fourth and fifth conductors 4, 5, 6, 7, 8) without being in direct contact with any of the other conductors.

[0081] When moisture or corrosion 30 occurs, for example, fluid or rust particles can bridge onto the conductor, such as Figure 1 Moisture or corrosion is shown to occur at the insulated or first non-detected portion 12 of the first conductor 4, the insulated or second non-detected portion 15 of the second conductor 5, the exposed or non-electrically insulated portion or third detected portion 17 of the third conductor 6, the insulated or fourth non-detected portion 21 of the fourth conductor 7, and the exposed or non-electrically insulated portion or fifth detected portion 23 of the fifth conductor 8. Therefore, there is electrical connectivity between the base conductor 3, the third conductor 6, and the fifth conductor 8.

[0082] The portions of the first, second, third, fourth and fifth conductors within the sensing region 26 of the elongated sensor 1 form a base two or binary distance measurement arrangement that measures the distance along the elongated sensor in terms of a first unit length. Thus, the elongated sensor can be used to measure the length of moisture or corrosion present with a resolution of the first unit length. The first conductor 4 indicates a value of one, the second conductor 5 indicates a value of two, the third conductor 6 indicates a value of four, the fourth conductor 7 indicates a value of eight and the fifth conductor indicates a value of sixteen. Thus, the value indicated by the Nth conductor will be 2 (N-1) . Figure 1 A letter and number 29 are shown indicating the function of the conductor, and thus the value indicated by the conductor as described immediately above, or in the case of the base conductor 3, the value indicated by the letter "B".

[0083] Therefore, when moisture or corrosion 30 bridges the conductor, such as Figure 1 As shown, where the third conductor and the fifth conductor are exposed, there is a continuity indication value of four between the base conductor 3 and one of the third detection portions 17 of the third conductor 6, and there is a continuity indication value of sixteen between the base conductor 3 and one of the fifth detection portions 23 of the fifth conductor 8. Thus, the elongated sensor provides continuity between the conductors that indicates moisture or corrosion in the twentieth unit distance from the sensing area along the elongated sensor, because in this example, the distance is four plus sixteen, which is twenty units, or twenty times the first unit length. As discussed above, the first unit length is a separate length of each of the first detection portions and each of the first non-detection portions.

[0084] An alternative interpretation method is to use binary numbers and interpret the lack of conductance as zero and conductance as one. The first conductor is the first unit in the binary number, the second conductor is the second unit, and so on. In the case of moisture location 30, the binary number formed by the conductance is "10100", which converts to the integer 20, indicating that the moisture or corrosion is located 20 first units of length along the elongated sensor.

[0085] Figure 1 A decimal scale 28 is included which provides a count per unit length portion. This is provided for clarity in the drawings, although a decimal scale marked on the elongated sensor may optionally be included. In this way, when, for example, moisture is detected under the insulation on a pipe at a certain length along the elongated sensor fixed to the pipe, a small amount of the insulation can be removed or pulled back to allow such visual distance markings to be read, thereby verifying that the correct pipe section has been found, before removing a certain length of insulation to expose moisture or corrosion.

[0086] The conductors may be held separate on an adhesive surface of a tape or similar strip of non-conductive carrier material, which adhesive surface also provides at least a portion of the location of the conductors relative to the object, at least during initial application or installation. Alternatively, the conductors may be bonded or otherwise secured to the tape, and the tape then held against the object by any known means. Alternatively or additionally, the conductors may be held closely together by braiding together with non-conductive threads, fibers or yarns, but prevented from direct contact with each other.

[0087] Regardless of how the elongated sensor is constructed, the individual conductors must be prevented from directly contacting each other, as any unintended conduction between the conductors may produce false indications where moisture or corrosion does not occur. This requirement may include holding or positioning the conductors adjacent to or parallel to each other while preventing contact between any of the conductors, including the base conductor and other conductors, regardless of whether the base conductor is Figure 1 An additional conductor in the elongated sensor shown is also an object such as a pipe or pipeline. The presence of moisture such as a conductive fluid and / or corrosion such as small rust particles must be able to create connectivity between the conductors to enable the location of the moisture or corrosion to be indicated, as described above.

[0088] Once corrosion of a metal object occurs, the moisture will contain a greater number of ions, such as iron oxide of iron or steel pipes, where the moisture is water, for example.

[0089] Figure 2 The first, second, third, fourth and fifth conductors 4, 5, 6, 7, 8 are shown woven together with a non-conductive carrier material 31, such as threads, fibers or yarns of a non-conductive material. The non-conductive carrier material is also preferably hydrophobic, such as glass fibers or polymer threads. Although the base conductors can be woven into the elongated sensor, it is Figure 2 is omitted in the example because the object against which the elongated sensor is held or fixed (such as a metal pipe) may form the base conductor.

[0090] The weave of the non-conductive carrier material 31 and the first, second, third, fourth and fifth conductors 4, 5, 6, 7, 8 must prevent the conductors from contacting or making direct electrical contact with each other, while maintaining the conductors close to each other, substantially parallel, and preventing direct electrical contact between the first, second, third, fourth and fifth conductors and the base conductor or any other external conductive surface. The weave must also allow the ingress of conductive media, such as conductive fluids such as water and conductive particles such as small rust particles, so that such conductive media can create electrical conduction between conductors that are exposed or uninsulated at moisture or corrosion sites.

[0091] The portion of the elongated sensor 1 before the start of the sensing region 26, such as the zero portion 27 of the elongated sensor, may be any length including zero. Figure 2In FIG. 1 , the zero portion 27 is shown as having a length less than one unit length. Each conductor requires an electrical connection 33 to enable connection to a connectivity detection circuit, a resistance measurement circuit, and / or other sensing circuits. Figure 2 In the embodiment, the elongate sensor 1 comprises a detector unit 32 which is in electrical communication with the first, second, third, fourth and fifth conductors 4 , 5 , 6 , 7 , 8 using electrical connections 33 .

[0092] exist Figure 2 , moisture or corrosion 30 creates connectivity between the base conductor (not shown) and the exposed or uninsulated portions of the second conductor 5 and the fifth conductor 8, i.e., one of the second detection portions 14 and one of the fifth detection portions 23. This indicates connectivity in the conductors of binary magnitude two and sixteen, i.e., connectivity in the eighteenth first unit length from the sensing area of ​​the elongated sensor. Alternatively, the binary number may be interpreted as "10010", which corresponds to the integer value 18.

[0093] The detector unit 32 may convert the sensed connectivity or sensed resistance between the conductors into an output signal indicating the distance and / or length in meters, for example, along the elongated sensor of any moisture or corrosion in the plurality of first units. This may be output to the software as a binary number or a converted number that may be directly related to the distance or position. The detector unit may provide the output signal over a wired and / or wireless connection. For example, the detector unit may wirelessly transmit the output signal to a monitoring system. The monitoring system may be a central monitoring system. Such a monitoring system may communicate with a plurality of elongated sensors, for example at different locations around an industrial plant.

[0094] The elongated sensor 1 may be part of a system for detecting moisture and / or corrosion. The system may comprise at least one sensor monitoring unit for receiving an output signal from at least one elongated sensor or detector unit. For example, the monitoring unit may be directly connected to each of the conductors of the elongated sensor and configured to detect the conductivity or resistance between the conductors. Alternatively, the monitoring unit may be connected to at least one detector unit which in turn is connected to the conductors of the elongated sensor.

[0095] like Figure 1 and Figure 2As shown, detecting connectivity or conductivity between conductors only at one end of each of the conductors may allow for detection of a single location of moisture or corrosion. By periodically monitoring connectivity between conductors, periods of moisture presence may be determined, and the risk of corrosion may therefore be estimated. Such periodic monitoring may be continuous, i.e., periodic continuous monitoring, such as measuring at a set frequency, such as every minute, or every 5 minutes, or every 15 minutes, or every hour. Alternatively, periodic continuous monitoring may measure a complete cycle, such as a day, or a startup cycle or a shutdown cycle, to capture moisture changes due to changes in environmental and / or operating conditions.

[0096] Measuring the resistance between the conductors not only gives an indication of location (providing connectivity through sufficient conductivity), but also the severity of moisture or corrosion (as conductivity increases, resistance decreases). By continuously monitoring the resistance between the conductors on a periodic basis, it is possible to again determine the period of time during which moisture is present, and therefore the likelihood of corrosion occurring. Additionally, more water and / or more corrosion, such as iron oxide in the water, will result in a lower resistance reading, and therefore provide an indication of the presence of increasing severity of corrosion.

[0097] The resistance, impedance and / or capacitance of moisture depends on the volume of the fluid, i.e., the actual contact area, the conductivity of the fluid, which may vary with the amount of metal ions present in the fluid and the number of locations of the fluid. This variability in conductivity may make it inaccurate or impractical to detect location using only the resistance on a pair of conductors or multiple similar conductors. However, using alternating portions of the conductors of an elongated sensor, if the resistance, impedance and / or capacitance is continuously monitored periodically, then the initial presence of moisture within a sensor portion may be detected and then subtracted from later resistance, impedance and / or capacitance measurements to indicate a change in severity, or, particularly in the case of measuring the resistance, impedance and / or capacitance between conductors at both ends of an elongated sensor, additional locations of moisture or corrosion may be identified, or predicted locations of moisture or corrosion may be rechecked.

[0098] Figures 3 to 5 A portion of an elongated sensor 1 is shown having five alternating partial conductors 4, 5, 6, 7, 8 and a base conductor 3, as shown in FIG. Figure 1 Since five alternating section conductors can provide binary numbers up to one hundred and twenty-eight, a decimal scale of sections 28 is shown, with sections twelve to one hundred and twenty-seven being cutouts in the figure.

[0099] exist Figure 3 in Figure 1 and Figure 2 The water block numbered 30 is now marked as R 1, and is located in the third region along the elongated sensor, that is, in the first unit length number three starting from the sensing region 26. Therefore, the first piece of moisture or corrosion R 1 Conductivity is provided to the first and second alternating portions of conductors having basis-1 and basis-2, respectively, thereby providing an indication of conductivity in the region of unit count three. This first block of moisture or corrosion has a resistivity R between each of the conductors 1 Therefore, there is a resistance R between the first and second alternating conductor sections. 1 , but there is essentially an open circuit or infinite resistance between any other pair of alternating portion conductors including at least one of the third, fourth or fifth conductors 6, 7, 8, which are insulated by area three on scale 28, i.e., insulated at the first unit length number three.

[0100] The actual resistance measured at the zero portion 27 between the first conductor 4 and the second conductor 5 is the resistance R 1 Add to this the resistance due to the conductor length per unit length of three from the zero portion to each of the first conductor 4 and the second conductor 5. The resistance per unit length of the conductor may be relatively low, for example, if the conductor comprises 0.25 mm diameter stainless steel wire (alternately coated with enamel for insulation), it will provide a resistance of about one ohm per meter. Therefore, if a piece of moisture or conductive R 1 If the resistance between the conductors is measured at the opposite end of the unit length 128, the length of the conductors included in the resistance measurement will be much greater, giving a larger resistance measurement than when measuring at the zero end of the elongated sensor. For example, if the unit length is four meters, the resistance at the zero end will be R 1 +24 ohms (from the 4 meter unit length, and 3 unit lengths on each of the 2 conductors), and the resistance from the 128 end will be R 1 +1000 ohms (from the example of 4 meter unit length, 125 unit lengths on each of 2 conductors, and one ohm per meter of conductor).

[0101] By measuring the resistance between a pair of conductors at the zero end and at the opposite end of the elongated sensor (in this case, after a unit length of 128), and comparing the two measurements, knowing the unit resistance of the conductors, it is possible to determine the amount of moisture or corrosion that creates a bridge resistance between the conductors. 1 Approximate location.

[0102] Furthermore, since the resistance of the conductors (e.g., one hundred and twenty-eight ohms for the entire length of each conductor) is typically much lower than the resistance R due to a patch of moisture or corrosion, 1(e.g., about 40,000 ohms for a water sample), so the location of a patch of moisture or corrosion can be determined. Due to the close proximity of all the conductors in the elongated sensor, a patch of moisture or corrosion R between the conductors 1 The resistance provided is typically substantially uniform, ie, fully conductive, or bulk R 1 The resistance between any pair of conductors at is usually the same value.

[0103] This approach, measuring the resistance between the conductor pair at each end of the elongated sensor, also allows the location of multiple patches of moisture or corrosion to be determined, regardless of the actual resistance at each location. This is based on the fact that the resistance across the relatively small conductor strip at any given location (i.e., between the exposed or sensing portions of the conductors) is substantially uniform, allowing all conduction, impedance, or capacitance at that location to be assumed to be the same value.

[0104] Figure 4 Shows for example the first block moisture or corrosion R 1 and the second piece of moisture or corrosion R 2 Thus, measuring from either end of the elongated sensor 1 between the first alternating section conductor 4 and the second alternating section conductor 5 gives 1 / (1 / R 1 +1 / R 2 ), ignoring for simplicity the relatively low resistance of the conductors themselves, since the two blocks provide two separate resistors in parallel between the first conductor 4 and the second conductor 5. For simplicity of explanation, if R 1 and R 2 Similarly, the resistance between conductors 4 and 5 is reduced to R 1 Measurements from either end of the elongated sensor 1 between the second alternating section conductor and the third alternating section conductor 6 give R 2 The total resistance of the conductor is , again ignoring for simplicity the resistance of the conductor itself (which is typically relatively low).

[0105] The resistance between any other pair of conductors including at least one of the fourth conductor 7 and / or the fifth conductor 8 will be substantially infinite because those conductors are 2 Based on these readings, it can be determined that there are two locations of moisture or corrosion and one with lower resistance (half R 1 ) corresponds to area three and indicates another position reading R 2 In zone seven, as indicated by scale 28.

[0106] Figure 5 Again showing for example the first piece of moisture or corrosion R 1 , where the second block moisture or corrosion R 2 Located with Figure 4In this example, adjacent or sequential pairs of measuring conductors provide only the R between the first conductor 3 and the second conductor 4. 1 However, measuring the resistance between the first conductor 3 and the fourth conductor 6 gives the resistance R between the first conductor 3 and the fourth conductor 6 2 However, measuring any other pair of alternating section conductors will provide essentially infinite resistance.

[0107] For example, due to a patch of moisture or corrosion, it is possible to detect which alternating partial conductors have continuity with the base conductor 3. Then, measuring the resistance between all alternating partial conductor pairs that have said continuity between themselves and the base conductor 3 can enable the detection of multiple patches of moisture or corrosion individually.

[0108] By providing a first end of the elongated sensor (such as at the zero portion or before the start of the sensing region 26) and again at the opposite end (at Figure 5 Measuring the resistance between each pair of conductors can more accurately detect or verify the location of more than two pieces of moisture or corrosion. Since the first piece of moisture or corrosion R 1 The first end of the elongated sensor is close, so the resistance between the first conductor 4 and the second conductor 5 measured at the first end of the elongated sensor will be lower than the resistance between the first conductor 4 and the second conductor 5 measured at the second end of the elongated sensor.

[0109] For example, if the unit length is 4 meters and the second piece has moisture or corrosion such as Figure 5 It is shown at position nine, i.e., between thirty-two and thirty-six meters from one end, and if the conductor resistance is one ohm per meter, then when measuring between the base conductor 3 and the fourth conductor 8 at the first end, then at the second end, the difference between the resistance readings at either end will be approximately eight hundred and eighty-eight ohms (two times the conductor length, minus four times the distance from the first end to the location, multiplied by the conductor resistance per first unit length). Thus, without considering the resistance of moisture or corrosion, the location of at least one defect can be determined by subtracting the resistance difference measured from one end to the other from two times the total conductor resistance and dividing by four times the conductor resistance per first unit length.

[0110] In the most common case, where the resistance at the location of moisture or corrosion is similar for all locations, the number of locations along a given pair of conductors where moisture or corrosion is present can be determined by taking twice the total conductor resistance and dividing by an integer percentage (preferably one hundred and ten percent) of the difference between the resistances measured from one end to the other. For some applications, the percentage used may be different, but is typically between one hundred and one hundred and thirty percent.

[0111] The resistance comparison can be performed between the base conductor and any of the other conductors, or can be performed between pairs of conductors with the base conductor disconnected. In this way, a unique location can be identified from a plurality of moisture or corrosion locations using a combination of the above methods. This then allows a comprehensive evaluation of the location among all moisture or corrosion locations by a process of elimination.

[0112] This process can provide or generate the locations or orientations of all moisture or corrosion events before any remedial action is taken, regardless of the number of locations or the resistance variations at different locations. In some cases, large changes in resistance can affect the results, but in the absence of a significant mismatch in the elongated sensor characteristics to the specific situation, the system is not significantly affected by the resistance variations at different locations.

[0113] While the example above gives a conductor resistance of approximately one ohm per meter, the resistance per unit length may be higher, or even lower per unit length. Using a resistance between a pair of conductors at a first end of an elongated sensor compared to the resistance of the same pair of conductors at a second, opposite end of the elongated sensor may not necessarily provide the same benefits as using alternating portions of conductors such as Figures 1 to 5 The position accuracy of each piece of moisture or corrosion in the detection part and the non-detection part of the first, second, third, fourth and fifth conductors in the same binary code. However, when there are multiple pieces of moisture or corrosion, the detected resistance R 1 , R 2 etc. can be used to help confirm the location and rate the severity of detected blocks.

[0114] Alternatively, if it is difficult to distinguish which exact locations are active (i.e., indicating moisture or corrosion at a particular time), then one can work through the locations step by step, starting at the furthest location, stripping away insulation or other coverings as needed, checking and fixing moisture at that location, and then continuing to the next location. The working range will be greatly reduced due to the elongated sensor approach, because, for example, if conductors 7 and 8 have infinite resistance, then this reduces the possible moisture locations to only one quarter of the total length of the elongated sensor, even if the resistance or conductivity of the other conductors is not known.

[0115] In all of the above explanations of resistance between conductors due to moisture between the conductors, impedance or capacitance may additionally or alternatively be used.

[0116] The alternating portion conductors, i.e., the first, second, third, fourth, and fifth conductors, are preferably corrosion resistant, such as made of stainless steel wire. In contrast, the base conductor may be corrodible. This allows the base conductor to corrode when moisture and conditions are favorable for corrosion over a period of time. The multiple corrodible base conductors may have different diameters in order to estimate corrosion rates. Alternatively, the corrosion resistant base conductor may be used alone or in combination with one or more corrodible base conductors.

[0117] Preferably, if Figure 6 As shown, at least one corrosion-resistant base conductor 3a is used together with at least one corrodible base conductor 3b.

[0118] The at least one corrodible base conductor may include additional corrodible wires of different sizes included in the elongated sensor, wherein the corrosion rate of the object is determined by the time it takes for the corrodible wires of the elongated sensor to corrode through, ie, lose continuous conductivity from one end to the other.

[0119] The object, particularly when it is a pipe, can be used as an additional base conductor. Since pipes are typically grounded, an optional external connector 34 (shown with a dashed connection line) can be provided to connect to the object or ground. This can enable an object such as a pipe to be used as an additional base conductor.

[0120] The conductor is typically a wire, and the insulating (or non-detecting) portion of the conductor is typically coated with enamel. However, other possible configurations of conductors having alternating insulating and non-insulating portions are contemplated. For example, the insulating portion of the conductor may be formed of a polymeric insulating material.

[0121] Alternatively, if Figure 6 As shown, the non-conductive carrier material may be a non-conductive strip or tape 40 to which the individual conductors are bonded, adhered or printed. The non-detecting portion of each conductor may then be printed or otherwise covered with a non-conductive material.

[0122] The conductors may be separate wires of different resistance (different materials or different cross-sections), as this may improve position detection.

[0123] The object for which the sensor or monitoring is used to detect surrounding moisture or its corrosion is typically a pipe, and the covering may be an insulating material, a fireproof material, a coating or protective layer such as rubber, or a mechanical protective layer, a thermosetting plastic layer, a refractory material or a counterweight layer. The object may alternatively be part of a structure, for example where corrosion may cause structural weaknesses, or indicate a leak or a problem causing unwanted moisture to enter the structure or around the structure. The object may alternatively be a plurality of beds or other items where any moisture present on an individual item is of interest, but, for example, the location on the individual items is less of interest. In this case, an eight-channel monitoring system and eight-wire cable may be used to monitor one hundred and twenty-seven items, which is preferred over using two wires for each of the one hundred and twenty-seven beds (i.e., two hundred and fifty-four wires and one hundred and twenty-seven monitoring channels).

[0124] The object being monitored for corrosion may be coated with a protective coating, such as paint or a corrosion resistant coating, and then surrounded by a covering such as an insulating material or a fireproofing material. An elongated sensor may be mounted below the covering, but above the coating (e.g., between the paint and the insulating material) to monitor where moisture accumulates below the covering before the coating fails, thereby indicating areas where the covering needs repair. Once the coating fails or decomposes, the object (such as a pipe or structure) will begin to corrode. At this point, the conductivity between the elongated sensor and the object itself will become apparent. This has the advantage that the elongated sensor can determine the presence and location of moisture before corrosion occurs, and then also identify the start time of corrosion. In this way, the elongated sensor signal can be risk-rated based on the known corrosion start date and the time when the corrosion is active (moisture is present). Alternatively, if the object has a coating, then even if there is no covering (such as a pipe with paint but no insulating material or fireproofing material), the elongated sensor can be mounted above the protective coating to monitor the decomposition of the protective coating. Alternatively, the elongate sensor may be mounted to the pipe before the pipe is painted, whereupon the elongate sensor may be mounted beneath the anti-corrosion coating and beneath any covering present (such as insulation or fire-resistant material, if any).

[0125] Where the object is a pipe or structural member having a vertical or non-horizontal portion, the elongate sensor is preferably wrapped around the vertical or non-horizontal portion. Where the object is a pipe or structural member having a substantially horizontal or non-vertical portion, the elongate sensor is preferably located along the underside of the object behind the lowest point of the section of the object where moisture is most likely to collect. Where the object has a bend or elbow between the vertical or non-horizontal portion and the horizontal or non-vertical portion, the elongate sensor is preferably located under the elbow against the object in an area where any moisture from the vertical or non-horizontal portion may leak, drip, collect or accumulate.

[0126] In addition to being preferably placed against the bottom of the pipe along its entire length, or spiraling around vertical portions of the pipe, the elongated sensor is also preferably placed under or spiraling around small bore outlet pipes and dead leg sections.

[0127] A similar elongated sensor may be used that is offset in position from the first elongated sensor. For example, a second elongated sensor may be used in parallel with the first elongated sensor to provide improved moisture detection and / or greater accuracy of the location of moisture detected. If the first elongated sensor is orbiting around the object, then the second elongated sensor may be orbited around the object, offset one hundred eighty degrees around the object to improve the surface area covered, or more elongated sensors may be used in parallel to further improve the surface area covered. Alternatively, a second elongated sensor slightly offset from the first elongated sensor may be used to improve the location accuracy. Alternatively, the second elongated sensor may be mounted in the opposite direction from the first elongated sensor to potentially improve the location accuracy of multiple locations of moisture or corrosion on the object.

[0128] By measuring the resistance between conductors, multiple elongated sensors can be used in series to monitor a greater length of pipe, pipeline or other object, while still allowing the exact location of moisture or corrosion to be determined. In this way, for example, an entire cross-country pipeline can be monitored.

[0129] Where multiple elongated sensors are used in series, respective resistors may optionally be added between at least one of the conductors of a first elongated sensor and an equivalent conductor of a second elongated sensor to aid in determining the location of moisture or corrosion. Resistors may be used between one or more of the equivalent conductors of each elongated sensor in the series.

[0130] Where the elongated sensor is used to monitor or detect degradation of a pipeline protective coating or corrosion due to degradation of the protective coating, the elongated sensor may be spiraled around the pipeline or object.

[0131] For any single length of object, multiple sets of two elongated sensors may be used instead of a single elongated sensor. For example, two elongated sensor sets may be wrapped helically around a pipeline below or above a protective coating to monitor conductivity and / or reduce resistance between the conductors of the elongated sensors and the pipeline.

[0132] The elongated sensor and / or the system incorporating such an elongated sensor provides many advantages. For example, it may allow active repair of the insulation material due to early detection of water. Due to the monitoring of the entire system in which the elongated sensor is installed, it may eliminate the risk of no water detection. Due to the identification of the location of water ingress within the first unit length, it allows only necessary local repairs to be performed, whereas normally the insulation of the entire line or a section of the line must be stripped to find out if there is a problem. Periodic continuous monitoring may allow the risk of corrosion to be determined based on the time spent in the presence of moisture. It allows continuous monitoring of the occurrence of corrosion via reducing the resistance between conductors and reducing the resistance between conductors and objects. The risk rating of the location along the object can be based on the time spent wet and based on the relative resistivity. By adding multiple sections of conductors and / or the same elongated sensor, very long lengths can be monitored, with global monitoring of the entire system or each section individually.

[0133] The shortest identifiable portion of the elongated sensor is determined by a first unit length, i.e., the length of each non-insulated portion or insulated portion on a first conductor, wherein the first conductor is the conductor having alternating insulated and non-insulated portions of the shortest length. The length of an object that can be monitored by a single elongated sensor can be increased by varying the number of conductors (e.g., in Figure 1 or Figure 2 The length of the first unit length may be adjusted by adding a sixth or base 32 conductor to the elongated sensor and / or by changing the first length. Since each insulated portion and each non-insulated portion of each conductor is twice the length of each insulated portion and each non-insulated portion of the previous conductor, changing the first unit length on the first conductor changes the length of the second unit length on the second conductor, and so on. However, changing the first unit length does change the shortest identifiable portion of the elongated sensor, i.e., the resolution of the elongated sensor in meters (or a similar length standard measure).

[0134] Preferably, the first unit length of the elongated sensor is between one meter and four meters, such as one meter, two meters or four meters, but may be less than one meter or greater than four meters.

[0135] It should be understood that the drawings are not drawn to scale. For example, if a typical conductor diameter is less than one millimeter, and a typical first unit length is between one and four meters, then the first unit length is thousands of times longer than the diameter of each of the conductors, rather than only 5.5 times longer as shown in the drawings.

[0136] Preferably, each elongate sensor comprises four to eight alternating conductor sections (such as Figure 1 and Figure 2 The five alternating section conductors 4, 5, 6, 7, 8 shown in FIG. 1 plus any uninsulated base conductors and corrodible conductors (such as Figure 13). However, more than 8 conductors may be used to facilitate monitoring of longer lengths.

[0137] The elongate sensor may alternatively be formed by printing conductors onto a non-conductive strip or tape, including printing insulating material over the conductor portions to form the non-sensing portion of each conductor.

[0138] The non-conductive material, such as a tape or non-conductive thread fabric, for example, must not only hold the conductors (including any base conductor) tightly together while preventing direct electrical contact between the conductors, allowing ingress of the conductive medium and preventing direct electrical contact of the conductors with the conductive outer surface, but should also substantially prevent axial movement of the conductors relative to each other. Most particularly, axial movement between any of the alternating portion conductors (i.e., the first conductor, the second conductor, the third conductor, etc.) should be substantially prevented. This is due to the binary coding characteristics provided by the alternating portion conductors, which will not function properly if the alternating portion conductors move axially relative to each other.

[0139] The system of the invention typically comprises at least one elongate sensor from which measurements are input to or acquired by a monitoring system or monitoring unit. The monitoring unit may then generate a prioritisation of risk locations and maintenance locations over time.

[0140] The system may comprise a detection unit for the or each elongate sensor or each group of elongate sensors, wherein the sensors are used in series, for example the detection unit measures the resistance between pairs of conductors of the sensors.

[0141] As the resistance increases, the conductivity decreases. Preferably, in the case where conductivity is present or determined to be present, the resistance is less than a selected resistance. For example, it may be assumed that when the resistance is less than 10 9 Ω, that is, less than ten to the ninth power, or <1,000,000,000 or less than one billion ohms. This number is arbitrary, so the number stated herein is given only as one possible example of a selected resistance.

[0142] Figure 7 A flow chart of a method 50 according to an aspect of the present invention is shown. The method begins with a step 51 of providing an elongated sensor of the type described above. That is, an elongated sensor for detecting moisture or corrosion on an object is provided, the elongated sensor comprising at least first, second, third, fourth and fifth conductors, each conductor having alternating detection portions and non-detection portions, the length of each detection portion and each non-detection portion of the first conductor having a unit length, and each Nth conductor having a unit length of 2. (N-1)The conductors are positioned parallel to each other by a non-conductive carrier material or tape, preventing the conductors from making direct electrical contact with each other or with an object while allowing the conductive medium to enter.

[0143] The step of providing the elongated sensor may include a step of providing at least one base conductor 52 and / or it may include a step of providing at least one external connector 53 and a step of connecting the external connector to an object or to ground 54. As discussed above, when the object is a pipe, the external connector may, for example, be connected to the pipe, or if the pipe is grounded, the external connector may be connected to ground.

[0144] In the step 52 of providing at least one base conductor, the or each base conductor is uninsulated but positioned parallel to one another and prevented from making direct electrical contact with one another while allowing access to a conductive medium.

[0145] The next step 55 is to mount the elongated sensor adjacent to the object. In the case where the object has a covering such as an insulating material, the sensor is preferably mounted adjacent to the object below the covering. If the pipe has a coating, the sensor may be mounted below the coating, or if there are multiple layers of coating and / or covering, the elongated sensor may be mounted between the multiple layers of coating and / or covering.

[0146] When monitoring connectivity 56 between the base conductor and at least the first, second, third, fourth and fifth conductors, any connectivity indicates the presence of moisture, so in step 57, if there is no connectivity, then no moisture or corrosion is detected on the object, so the method continues to pause and then repeats step 58.

[0147] However, if there is any connectivity at step 57, then the presence of moisture or corrosion on the object is determined. The connectivity of the different conductors of the elongated sensor can be used to identify 59 the location or orientation of moisture, especially if there is only a single location or orientation of moisture. Only the binary coded nature of the elongated sensor needs to be interpreted to identify 59 the location or orientation of moisture. However, if there are multiple locations or orientations of moisture, then the step 60 of measuring the resistance, capacitance and / or impedance between the conductors can be used at step 61 to identify the number of locations and / or orientations of multiple locations of moisture or corrosion on the object.

[0148] Regardless of whether one or more locations of moisture or corrosion are detected, the location of the location is output at step 62. Even if moisture has been detected, the method may continue to pause after outputting any location and repeat step 58. In step 58, the pause may last for a predetermined length of time, or the pause may last for a length of time determined by environmental conditions, operating conditions, etc.

[0149] In the appended claims and in the foregoing description of the invention, unless the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" are used in an inclusive sense, i.e. to specify the presence of recited features in various embodiments of the invention, but not to exclude the presence or addition of further features.

Claims

1. An elongated sensor for use in a system for detecting moisture and / or corrosion, the elongated sensor comprising at least a first conductor, a second conductor, and a third conductor, each of the at least first, second, and third conductors being positioned parallel to each other by a non-conductive carrier material to prevent the conductors from coming into direct conductive contact with each other or with external conductive surfaces while allowing ingress of a conductive medium; The first conductor is exposed or non-electrically insulated for a first unit length to form an initial first detection portion and then alternately electrically insulated for a distance equal to the first unit length to form a first non-detection portion or non-electrically insulated for a distance equal to the first unit length to form an additional first detection portion of the first conductor; the second conductor being electrically insulated a distance equal to the second unit length minus the first unit length to form an initial second non-detecting portion and then alternately being electrically non-insulated a distance equal to the second unit length to form a second detecting portion or being electrically insulated a distance equal to the second unit length to form an additional second non-detecting portion of the second conductor, the second unit length being twice the first unit length; The third conductor is electrically insulated a distance equal to the third unit length minus the first unit length to form an initial third non-detection portion, and then alternately electrically non-insulated a distance equal to the third unit length to form a third detection portion, or electrically insulated a distance equal to the third unit length to form a non-detection portion of the third conductor, the third unit length being twice the second unit length.

2. The elongated sensor of claim 1, wherein the at least first, second and third conductors further comprise a base conductor, The base conductor is exposed or uninsulated and is positioned parallel to the first, second and third conductors through the non-conductive material.

3. An elongate sensor according to claim 2, further comprising at least one additional base conductor, wherein the or each additional base conductor is corrodible.

4. The elongated sensor of claim 1, wherein at least one of the at least first, second and third conductors further comprises a resistor connected in series with the respective conductor.

5. The elongated sensor of claim 1, wherein at least one of the at least first, second and third conductors further comprises at least two resistors connected in series with the respective conductor and equidistantly distributed along the respective conductor.

6. The elongated sensor of claim 1, wherein the first unit length is up to and including 4 meters.

7. The elongated sensor of claim 1, wherein the elongated sensor is held, adhered or fixed beneath a substantially horizontal object and / or hovers around a substantially vertical object.

8. The elongated sensor of claim 1, comprising a fourth conductor; The fourth conductor is electrically insulated by a distance equal to a fourth unit length minus the first unit length to form an initial fourth non-detection portion, and then alternately electrically non-insulated by a distance equal to the fourth unit length to form a fourth detection portion, or electrically insulated by a distance equal to the fourth unit length to form a fourth non-detection portion of the fourth conductor, the fourth unit length being twice the third unit length.

9. An elongate sensor as claimed in claim 8, comprising an Nth conductor. The Nth conductor is electrically insulated by a distance equal to the Nth unit length minus the first unit length to form an initial Nth non-detection portion, and then alternately electrically non-insulated by a distance equal to the Nth unit length to form an Nth detection portion, or electrically insulated by a distance equal to the Nth unit length to form an Nth non-detection portion of the Nth conductor, the Nth unit length being twice the first unit length. (N-1) times.

10. The elongated sensor of claim 1, wherein the non-conductive carrier material and the conductor are braided together.

11. An elongate sensor according to claim 1 , wherein the non-conductive carrier material is a strip or tape to which the conductor is fastened or printed.

12. The elongate sensor of claim 1, comprising a detector unit electrically connected to each conductor.

13. A system for detecting moisture and / or corrosion of an object, the system comprising at least one elongated sensor and a monitoring unit; The elongated sensor comprises at least a first conductor, a second conductor and a third conductor, each of the at least first, second and third conductors being positioned parallel to one another by a non-conductive carrier material to prevent the conductors from coming into direct conductive contact with one another or with an external conductive surface while allowing ingress of a conductive medium; The first conductor is exposed or non-electrically insulated for a first unit length to form an initial first detection portion and then alternately electrically insulated for a distance equal to the first unit length to form a first non-detection portion or non-electrically insulated for a distance equal to the first unit length to form an additional first detection portion of the first conductor; the second conductor being electrically insulated a distance equal to a second unit length minus the first unit length to form an initial second non-detecting portion and then alternately being electrically non-insulated a distance equal to the second unit length to form a second detecting portion or being electrically insulated a distance equal to the second unit length to form a non-detecting portion of the second conductor, the second unit length being twice the first unit length; the third conductor being electrically insulated a distance equal to a third unit length minus the first unit length to form an initial third non-detecting portion and then alternately being electrically non-insulated a distance equal to the third unit length to form a third detecting portion, or being electrically insulated a distance equal to the third unit length to form a non-detecting portion of the third conductor, the third unit length being twice the second unit length; The monitoring unit is individually connected to each of the at least first, second and third conductors and is configured to detect conductivity between any pair of the at least first, second and third conductors.

14. The system of claim 13, further comprising a base conductor, wherein the monitoring unit is configured to detect conductivity between any pair of the conductors including the base conductor and the at least first, second and third conductors.

15. A system as claimed in claim 14, wherein the base conductor is included in the slender sensor, is uninsulated and is positioned parallel to the at least first, second and third conductors by the non-conductive carrier material to prevent direct electrical contact with the conductors or any external surface and allow the ingress of conductive media.

16. The system of claim 14, wherein the elongated sensor hovers around or remains adjacent to or against the underside of an object, The object is electrically conductive and forms the base conductor.

17. The system of any one of claims 14 to 16, wherein the monitoring unit converts the detected conductivity between the base conductor and the at least first, second and third conductors into a decimal number of a first unit length or into a distance.

18. The system of any one of claims 14 to 16, wherein the monitoring unit detects resistance, impedance and / or capacitance between individual pairs of the conductors and determines the location of at least one location or area of ​​corrosion or moisture.

19. The system of claim 18, wherein the monitoring unit is connected to a first end and a second end of each of the conductors and detects and compares the resistance, impedance and / or capacitance measured from the first end with the resistance, impedance and / or capacitance measured at the second end.

20. The system of claim 13, wherein the monitoring unit is directly connected to the conductor of the elongated sensor.

21. The system of claim 13, wherein the monitoring unit is indirectly connected to the conductor of the elongated sensor, The elongated sensor comprises a detector unit, the monitoring unit being connected to the detector unit of the elongated sensor.

22. The system of claim 13, wherein the monitoring unit obtains readings from the elongate sensor at predetermined time intervals.

23. The system of claim 13, wherein the monitoring unit converts the detected conductivity between the conductor pair into a decimal number of a first unit length or into a distance.

24. The system of claim 13, further comprising a base conductor, which is an additional conductor in the elongated sensor or is the object, wherein the monitoring unit is configured to measure the resistance, impedance and / or capacitance between individual pairs of the conductors including the base conductor and the first, second and third conductors.

25. The system of claim 24, wherein the monitoring unit converts resistance, impedance and / or capacitance between the pairs of the at least first, second and third conductors to determine the location of at least one area of ​​corrosion or moisture.

26. The system of claim 25, wherein the monitoring unit is connected to a first end and a second end of each of the conductors and detects and compares the resistance, impedance and / or capacitance measured from the first end with the resistance, impedance and / or capacitance measured at the second end.

27. The system of claim 13 or 24, wherein the sensor monitoring unit periodically measures conductivity and / or resistance, impedance and / or capacitance in the at least one elongated sensor, The sensor monitoring unit records or tracks the time period during which the detection portion detects moisture.

28. The system of claim 13 or claim 24 or claim 27, wherein the at least one elongate sensor comprises a plurality of elongate sensors on a plurality of monitored objects, The measured conductivity and / or resistance, impedance and / or capacitance from each sensor is transmitted to the monitoring unit.

29. The system of claim 13, wherein the at least one elongated sensor is placed beneath a covering on the object.

30. A method of detecting moisture or corrosion on an object, the method comprising: An elongated sensor is provided comprising at least first, second, third, fourth and fifth conductors, each conductor having alternating detection portions and non-detection portions, the length of each detection portion and each non-detection portion of the first conductor having a unit length, each Nth conductor having a detection portion length and a non-detection portion length that are 2(N-1) times the unit length, the conductors being positioned parallel to each other by a non-conductive carrier material or tape, preventing the conductors from coming into direct electrical contact with each other or with the object, while allowing entry of a conductive medium.

31. A method according to claim 30, wherein providing an elongate sensor comprises providing at least one base conductor, the or each base conductor being uninsulated but positioned parallel to each other and prevented from coming into direct electrical contact with each other whilst allowing entry of a conductive medium.

32. A method according to claim 30 or claim 31, wherein providing an elongate sensor comprises providing at least one external connector, The method further comprises connecting the external connector to the object or to ground, the external connector forming part of an external base conductor, the external base conductor forming the base conductor or part of a base conductor.

33. A method according to claim 31 or claim 32, comprising mounting the elongate sensor adjacent the object.

34. The method of claim 33, comprising monitoring connectivity between the base conductor and at least the first, second, third, fourth and fifth conductors.

35. The method of claim 34, comprising determining the presence of moisture or corrosion on the object: if no moisture or corrosion is detected on said object, then after a pause of a predetermined period of time, repeating said monitoring of connectivity; If moisture or corrosion is detected on the object, the location of the moisture or corrosion on the object is calculated and reported.

36. The method of claim 34, comprising determining the presence of moisture or corrosion on the object: if no moisture or corrosion is detected on said object, then after a pause of a predetermined period of time, repeating said monitoring of connectivity; If moisture or corrosion is detected on the object, the resistance, capacitance and / or impedance of any or each connection between the base conductor and at least the first, second, third, fourth and fifth conductors is measured to calculate and report at least one location of the moisture or corrosion on the object.

37. The method of claim 33, comprising measuring resistance, capacitance and / or impedance between at least the first, second, third, fourth and fifth conductors; Determine the presence of moisture or corrosion on the object: if no moisture or corrosion is detected on the object, then after a pause of a predetermined period of time, repeating said measuring resistance, capacitance and / or impedance; If moisture or corrosion is detected on the object, at least one location of the moisture or corrosion on the object is calculated and reported.

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