Device and method

Abstract

The present invention provides an apparatus and a method. The apparatus described herein is used to measure and / or monitor the magnetic field strength inside a sample. The apparatus includes: a fixing unit made of a non-magnetic material; a magnetic field strength measuring device having a sensor; and a first elongated member and a second elongated member. The elongated members are made of a material having a high relative magnetic permeability. The elongated members have a first end and a second end, respectively. The fixing unit supports the elongated members in a fixed posture to form a gap by positioning the first end of the first elongated member and the first end of the second elongated member in relative positions to each other. The fixing unit supports the sensor of the measuring device inside the gap or substantially inside the gap.

Description

Technical Field

[0001] The present invention relates to a device for measuring the magnetic field strength inside a sample of ferromagnetic material and a method for measuring the magnetic field strength inside a sample in a non-destructive manner. Background Art

[0002] Monitoring subsea equipment is a critical task for oil and gas companies. This is because the consequences of equipment failure can be catastrophic. One example is monitoring corrosion on subsea pipelines. Subsea pipelines, located on the seabed or buried deep within the ocean floor in trenches, transport substances such as oil, gas, or water.

[0003] Pipeline dimensions and materials vary depending on their intended use. Pipeline diameters range from 50 mm to 2 m, with wall thicknesses from 10 mm to 75 mm. To remain operational on the seabed for up to 20 years, pipelines must be constructed from strong and durable materials. Therefore, pipelines are typically made of high-strength steel, which is inherently ferritic and therefore capable of magnetization.

[0004] One of the threats to pipeline life is corrosion, particularly internal corrosion. While external corrosion on a pipeline is easy to inspect, monitoring internal corrosion is extremely difficult. Specifically, localized corrosion poses a unique threat. This is because localized corrosion is faster than general corrosion and has uneven growth characteristics, making it difficult to predict.

[0005] In the case of inspecting pipelines, non-destructive testing techniques are preferred over destructive testing techniques. This is because non-destructive testing techniques do not cause any disturbance in the flow in the pipeline. Existing technologies include eddy current and magnetic flux leakage. However, these technologies require a large amount of electricity to operate. In addition, in the existing technologies, a large amount of data is generated, so it is not suitable to be left in place for a long time, and therefore it is almost impossible to use them on the seabed for continuous monitoring purposes. The use of ultrasonic sensors for continuous monitoring has been developed for many years. However, the measurability of ultrasonic waves covering a large area of the pipeline surface is difficult, and the monitoring of local degradation in the ultrasonic sensor grid is ineffective. Another issue with seabed monitoring technology based on ultrasonic waves is that the cost of the unit components increases the overall cost of the equipment, and multiple sensor devices cannot be configured to fully cover high-risk locations.

[0006] In addition to the above, existing technologies for measuring corrosion are not suitable for long-term, i.e., 20-year, settings for a variety of reasons, including: the constant need for large amounts of power; the need for periodic interaction with divers or robots; the inability of existing components to operate for such extended periods; the inability of existing components to operate at high pressures; the need for consumables that are not readily available; and the inability of existing components to operate over a wide temperature range (0-80 degrees Celsius).

[0007] The interior of a submarine pipeline can be inspected using pigs that are passed along the inside of the pipeline (in-line inspection). These devices use magnetic flux leakage and / or ultrasonic methods. However, the main disadvantage of these techniques is that the pipeline must be "pigable," meaning that there must be no obstructions inside the pipeline and the pipeline geometry must be of the appropriate shape.

[0008] Therefore, the data available on the condition of subsea pipelines and other such structures is very limited due to the high cost and complexity of the equipment required to monitor these conditions, as the equipment needs to withstand the harsh environment of the seabed.

[0009] Currently, there is no method that provides continuous measurement of the magnetic field within the pipe wall. Furthermore, there is generally no method that measures the magnetic field inside magnetized materials.

[0010] Therefore, there is a need for a system that can directly monitor the wall thickness condition of ferrite materials in a non-destructive manner. The system should not require major intervention, should not require a large amount of energy, and should be able to function indefinitely. Summary of the Invention

[0011] Therefore, an object of the present invention is to provide a novel measuring device for ferrite material that is capable of monitoring / measuring the magnetic field strength inside the ferrite material.

[0012] The above-mentioned problem is related to submarine pipelines, but the present invention is not limited to such applications. The present invention can be applied to any device or structure that obtains a measurement value of the magnetic flux density inside a sample.

[0013] According to a first embodiment of the present invention, a device for measuring the magnetic field strength inside a sample is provided. The device may include a fixing unit made of a non-magnetic material. The device may include a magnetic field strength measuring device having a sensor. The device may include a first elongated member and a second elongated member. The elongated member may be made of a material having a high relative magnetic permeability. The elongated members may have a first end and a second end, respectively. The fixing unit may support the elongated members in a fixed posture to form a gap by positioning the first end of the first elongated member and the first end of the second elongated member at positions opposite to each other. The housing may support the sensor of the measuring device inside the gap or substantially inside the gap. The sample may be made of a ferromagnetic material. The elongated members may be respectively configured to be present on the surface of the sample or adjacent to the surface of the sample.

[0014] The fixing unit may be a housing. The fixing unit may be a temporary or permanent fixing unit. The fixing unit may be a non-magnetic bolt or clamp. The fixing unit may be a weld or an adhesive.

[0015] Each of the elongated members may have a longitudinal axis. The center of the longitudinal axis is substantially coincident with the center of the longitudinal axis of the other elongated members. This ensures that the magnetic field is measured in only one direction. The longitudinal axis may extend from the first end to the second end of each elongated member.

[0016] The longitudinal axis of the elongated member may coincide with the longitudinal axis of the specimen.

[0017] The elongated member may be made of a material such as Hiperco 50 and Hiperco 50A having a low relative remanence of less than about 100 microtesla.

[0018] The first end of the elongated member may include a tapered portion that reduces the area of the cross section of the elongated member to the same or substantially the same area as the cross section of the sensor on the measuring device. This is to concentrate the magnetic field passing through the area of the small cross section so that the sensor obtains a higher reading value. As a result, more accurate readings can be made. In addition, in the present invention, although the actual value of the magnetic field in the pipe wall is not measured, a value proportional to the value is measured. This is because of the unexpected technical effect that the magnetic field strength inside the sample is proportional to the magnetic field strength inside the elongated member. Whether the proportional relationship is constant is determined by the shape of the elongated constituent element. Therefore, by increasing the contact area with the surface to be measured and / or reducing the area of the cross section, the constancy of the proportional relationship is further increased.

[0019] The magnetic field strength measuring device may include a Hall effect sensor, or a magnetoresistive sensor or any other type of magnetometer.

[0020] The housing may have at least one connection portion suitable for connecting a cable. The housing may have multiple connection portions for connecting cables. The connection portions of the housing may be sealed to prevent water infiltration. As long as the elongated member and the magnetic field strength measurement device are maintained in a fixed position, the housing may not be required.

[0021] The sample can be a metal conduit such as a pipe. The sample can be any ferrite material. The sample can be any shape and size. For an accurate reading, the sample should ideally be at least 2-3 times larger than the device.

[0022] The housing and the strip member may be mounted on the sample. Alternatively, the device may be disposed on the sample. The device may be permanently fixed to the sample. The device may be fixed by screws, adhesives, or any other type of fastening mechanism. In order to measure the different magnetic field strengths throughout the sample, there may be an array of devices fixed to the sample. In order to measure the magnetic field strength of the sample in different directions, the devices may be disposed in different directions. The array may provide a detailed data set of the sample state. There may be additional monitoring equipment disposed near the device of the present invention. Such additional equipment may be used to measure the magnitude and direction of the magnetic field emanating from the surface of the sample. These additional monitoring devices may be calibrated by reference to the values of the magnetic field inside the sample shown in the present invention.

[0023] The measuring equipment can measure magnetic field strength from 0 to + / - 15,000 gauss or up to the magnetic saturation level of the sample. In addition, the measuring equipment can measure the magnetic field as a positive or negative value within the sample, indicating the direction of the magnetic flux inside the sample.

[0024] The first elongated member and the second elongated member may each have a contact surface on a side closer to the second end than the first end that is in surface contact with the sample.

[0025] The first elongated member and the second elongated member may each have an extension portion extending away from the sample between the first end portion and the second end portion, wherein the closer the extension portion is to the first end portion, the further away from the sample the extension portion is.

[0026] The first elongated member and the second elongated member may be wider at the contact surface than at the extension portion.

[0027] The contact surface may be curved in the width direction of the first elongated member or the second elongated member having the contact surface.

[0028] The contact surface may be curved in the length direction of the first elongated member or the second elongated member having the contact surface.

[0029] The magnetic resistance between the contact surface of the first elongated member and the contact surface of the second elongated member in the device may be smaller than the magnetic resistance between the contact surface of the first elongated member and the contact surface of the second elongated member in the sample.

[0030] The apparatus may further include a transmitting unit that transmits measurement data of the magnetic field intensity measuring device.

[0031] The magnetic permeability of the first elongated member and the second elongated member may be higher than the magnetic permeability of the sample.

[0032] According to a second embodiment of the present invention, a method for measuring and monitoring the magnetic field strength within a sample is provided. The method may include installing or configuring the apparatus of the first embodiment of the present invention on the sample. The method may include using a magnetic field strength measuring device to measure the magnetic field strength passing through the elongated member. The method may include monitoring the magnetic field strength passing through the sample by monitoring the magnetic field strength passing through the elongated member.

[0033] The above method provides a non-destructive way to measure and monitor the strength and direction of the magnetic field inside a specimen. By exploiting the unexpected fact that the magnetic field strength inside the specimen and the magnetic field strength inside an elongated member are proportional to each other, the magnetic field strength inside the specimen can be calculated by measuring the magnetic field strength inside the elongated member. The "constant coefficient" in this relationship can be determined physically or through computer modeling.

[0034] The above method allows calibration of other equipment for determining corrosion inside pipelines. In the event of a large increase in the magnetic field outside the pipeline being detected, it is important to know whether this is due to shallow corrosion combined with high internal magnetization or deep corrosion caused by low internal magnetization.

[0035] The method may further include establishing a relationship between the magnetic field strength within the elongated member and the magnetic field strength within the sample. This may be performed through computer modeling or experimentation. The step of measuring and monitoring the magnetic field strength within the sample may be performed to monitor a cross-sectional area of the sample.

[0036] The device can be mounted on a specimen with the longitudinal axis of the elongated member aligned with the specimen's first axis, thereby measuring and monitoring the magnetic field intensity passing through the specimen in the same direction as the first axis. The direction of the magnetic field within the specimen measured by the device is defined by the device's longitudinal axis. When measuring the magnetic field within a pipe wall, the circumferential magnetic field component within the pipe should be measured. The device can also be mounted in a direction intersecting the pipe's axial direction. When mounted along a pipe, the device measures the component of the magnetic field along the pipe.

[0037] A third aspect of the present invention provides a method for measuring and monitoring the magnetic field strength inside the sample of the second aspect of the present invention, wherein the method uses a plurality of devices to measure the magnetic field strength in various directions and orientations.

[0038] A fourth aspect of the present invention provides a measurement system comprising multiple devices according to the first aspect of the present invention. These devices can be positioned inside a casting. The devices can be configured to measure the magnetic field intensity in the longitudinal direction and in a direction perpendicular to the longitudinal direction within the specimen. Multiple devices can be positioned at various locations around the specimen. For example, in the case of a pipeline, four to six devices can be evenly spaced around the outer circumference of the pipeline.

[0039] Further arbitrary features disclosed in association with each embodiment of the present invention correspond to further arbitrary features of other embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The present invention will be described below with reference to the accompanying drawings without limiting the exemplary embodiments.

[0041] Figure 1 A perspective view showing a device according to an embodiment of the present invention.

[0042] Figure 2 express Figure 1 A top view of the device.

[0043] Figure 3 express Figure 1 and Figure 2 Side view of the device in.

[0044] Figure 4 Shown is a casting comprising two embodiments of the device in a mutually perpendicular position.

[0045] Figure 5 It shows the first end portion of the first elongated member of the present invention.

[0046] Figure 6 A magnetic field intensity measuring device is shown as an example of an embodiment of the present invention.

[0047] Figure 7 This is a graph showing the relationship between the magnetic field intensity in the apparatus of the present invention and the magnetic field intensity in the sample being measured. DETAILED DESCRIPTION

[0048] Figure 1A perspective view of an apparatus 100 according to an embodiment of the present invention is shown. The apparatus 100 is shown together with a housing 104, a magnetic field strength measuring device 106, and two elongated members 110a / b. The apparatus 100 is shown as being suitable for a curved sample 102 such as a pipeline (also known as a pipe). This should not be construed as limiting, as the apparatus 100 can be used on samples 102 of any shape / geometry. The sample 102 can be rectangular, flat, hexagonal, triangular, or any other such shape. Furthermore, the sample 102 can be made of any material that can be magnetized and measured, and can be made of a metal material, for example.

[0049] The elongated members 110a / b each have a first end 112a / b and a second end 114a / b. The elongated members 110a / b are typically made of a material having a high relative permeability greater than 500 (the ratio of the permeability of the medium to the permeability of free space, so the unit is dimensionless). Due to the high relative permeability, the elongated members 110a / b can be rapidly magnetized by the sample. The permeability of the elongated members 110a / b can be higher than the permeability of the pipeline sample 102. Thus, when the elongated members 110a are arranged on the surface of the sample 102, the magnetic flux flows from the surface of the pipeline sample 102 into the elongated members 110a / b.

[0050] In addition, the elongated members 110a / b are typically made of a material with a low relative remanence of less than 100 microteslas. Due to the low relative remanence, the elongated members 110a / b can be demagnetized, preventing any significant remanence from forming. This is important for accurate measurement of magnetic field strength.

[0051] Figure 1 The elongated members 110a / b shown are approximately 150 mm long and 25 mm wide, and are tapered with a width of approximately 3 mm. The width of the gap 116 is approximately 3 mm. The total height of the device 100 above the sample 102 is approximately 10 mm.

[0052] The housing 104 should be made of a non-magnetic material so as not to hinder the accuracy of the device 100. The main purpose of the housing 104 is to orient the elongated members 110a / b in a fixed posture and form a gap 116. The size of the gap 116 is an important feature of the present invention and must be maintained to ensure the accuracy of the measurement results. The gap 116 is essentially formed between the first end 112a of the first elongated member 110a and the first end 112b of the second elongated member 110b. The gap 116 is suitable for the magnetic field strength measuring device 106 to be embedded inside. The housing 104 configures the sensor 108 of the magnetic field strength measuring device 106 inside the gap 116 or substantially inside the gap 116, and fixes the magnetic field strength measuring device 106 in a fixed position relative to the gap 116. Typically, the gap is 2 mm or sufficient to enable the magnetic field sensor to be embedded.

[0053] The housing 104 may arrange the long strip members 110a / b in such a manner that the long strip members 110a / b are present on the surface of the sample 102 or adjacent to the surface of the sample 102. Figure 2 As shown, the elongated members 110a / b have longitudinal axes 118a / b, respectively. In the first elongated member 110a, the longitudinal axis 118a passes through the first end 112a and extends toward the second end 114a. In the second elongated member 110b, the longitudinal axis 118b passes through the first end 112b and extends toward the second end 114b. Figure 2 In the embodiment, the housing 104 arranges the elongated members 110a / b so that their longitudinal axes 118a are parallel to each other and pass through the same point. The elongated members 110a / b are preferably aligned as a whole relative to the device to ensure proper function. Furthermore, as long as the central axis of the first end 112a is aligned with the central axis of the first end 112b, the other portions of the elongated members 110a / b do not need to be aligned on the same straight line.

[0054] When the apparatus 100 is positioned over the sample 102, the elongated members 110a / b (due to their high relative transmittance) are magnetized by the sample 102, which is typically at least two to three times larger than the elongated members 110a / b. The magnetic intensity of the elongated members 110a / b along the longitudinal axis 118a / b is proportional to the magnetic intensity of the sample 102 along the parallel axis. Consequently, the magnetic field intensity passing through the sample 102 is proportional to the magnetic field intensity passing through the elongated members 110a / b. Because the gap 116 between the elongated members 110a / b is small, the magnetic field passing through the gap 116 can be measured by the sensor 108 on the magnetic field strength measurement device 106. The magnetic field strength measurement device 106 is configured to measure the magnetic flux passing through the gap 116, which generates the magnetic flux passing through the elongated members 110a / b. By using this value to correlate the measured value passing through the elongated members 110a / b with the sample 102, the magnetic flux passing through the sample 102 can be calculated. The present invention can be used to represent static magnetic fields rather than alternating magnetic fields.The magnetic field measured by the present invention needs to be constant during the period during which the reading is taken, for example, 1 second.

[0055] The above phenomenon provides a non-destructive method for measuring the magnetic field strength inside the sample 102, which is not known in the art, and does not interfere with the sample 102 itself. The device 100 described in this specification can be configured on the sample 102 to monitor and measure the magnetic field strength in an easy manner.

[0056] Whether the proportional relationship is constant depends on the dimensions of the first and second elongated members 110a / b and, to a lesser extent, the thickness of the specimen 102. Whether the proportional relationship is constant can be determined by physical experimentation or by computer modeling the apparatus 100 relative to the specimen 102. Thus, the apparatus 100 provides a method for determining the magnetic flux density within the material of the magnetized specimen 102.

[0057] Figure 3 express Figure 1 and Figure 2 1. A side view of the device in FIG. Device 100 is configured to accommodate a semicircular specimen 102, such as a pipeline. The bottom surfaces of the elongated members 110a / b are shaped to lie along the transverse axis of the pipeline specimen 102. In this configuration, device 100 can measure magnetic flux transversely through the pipeline specimen 102.

[0058] For example, the elongated members 110a / b may each have a contact surface 1140 at the second end 114a / b that contacts the pipeline specimen 102. This ensures that magnetic flux flows reliably from the surface of the pipeline specimen 102 through the elongated members 110a / b to the magnetic field intensity measurement device 106. However, the contact surface 1140 need not be located at the second end 114a / b, as long as it is located closer to the second end 114a / b than the first end 112a / b.

[0059] The contact surface 1140 may be curved in the width direction (in this embodiment, the transverse direction of the pipeline specimen, as an example) of the elongated member 110a or 110b having the contact surface 1140. Thus, the elongated members 110a / b can be arranged along the surface of the pipeline specimen 102 in the transverse direction of the pipeline specimen 102.

[0060] Furthermore, as can be readily imagined, when the device 100 is oriented along the longitudinal axis of the pipeline specimen 102, it is not necessary to properly curve the bottom surface of the elongated member 110a / b. In this case, the contact surface 1140 can be curved in the longitudinal direction of the elongated member 110a or 110b having the contact surface 1140, that is, in the longitudinal direction of the pipeline specimen 102.

[0061] The elongated members 110a / b may each have an extension portion 113 extending away from the pipeline specimen 102 between the first end portion 112a / b and the second end portion 114a / b. This prevents magnetic flux flowing from the pipeline specimen 102 into the elongated members 110a / b via the contact surface 1140 from returning to the pipeline specimen 102, thereby reliably allowing the magnetic flux to pass through the magnetic field strength measuring device 106 for measurement of the magnetic field strength.

[0062] In this embodiment, a standing surface 1141 is provided between the bottom surface of the extension portion 113 (i.e., the surface facing the pipeline sample 102) and the contact surface 1140, thereby reliably separating the extension portion 113 from the pipeline sample 102. However, the bottom surface of the extension portion 113 (i.e., the surface facing the pipeline sample 102) and the contact surface 1140 may be continuous or directly adjacent to each other without a standing surface or cutout therebetween.

[0063] The shape of the extension portion 113 can be continuous in the extension direction. For example, in a cross-section of the extension portion 113 along the extension direction, the bottom surface of the extension portion 113 and its opposite surface (also referred to as the top surface) can be tangentially continuous at adjacent points. This prevents magnetic flux flowing from the pipeline sample 102 into the elongated member 110a / b via the contact surface 1140 from leaking out of the elongated member 110a / b through the surface of the extension portion 113.

[0064] In addition, the bottom surface of the extension portion 113 may be a flat surface or a curved surface. In the case where the bottom surface of the extension portion 113 is a curved surface, the bottom surface may be curved in the length direction or in the width direction of the elongated member 110a / b.

[0065] Furthermore, the top surface of the extension portion 113 may be a flat surface or a curved surface. When the top surface of the extension portion 113 is a curved surface, the bottom surface may be curved in the length direction or in the width direction of the elongated member 110a / b.

[0066] The closer to the first end 112a / b (the end on the gap 116 side), the farther the extension 113 is from the pipeline sample 102. This reliably prevents the magnetic flux flowing from the pipeline sample 102 into the long member 110a / b via the contact surface 1140 from returning to the pipeline sample 102.

[0067] Here, the elongated members 110a / b can be wider at the contact surface 1140 than at the extension portion 113. This ensures that magnetic flux can flow reliably from the surface of the pipeline specimen 102 to the elongated members 110a / b. Furthermore, the width of the elongated members 110a / b can be a dimension perpendicular to the length of the elongated members 110a / b (in this embodiment, the longitudinal axis of the pipeline specimen 102, as an example). The width of the elongated members 110a / b at the contact surface 1140 can be the width of the area where the contact surface 1140 contacts the pipeline specimen 102.

[0068] Furthermore, the magnetic resistance between the contact surface 1140 of the elongated member 110a and the contact surface 1140 of the elongated member 110b in the apparatus 100 can be smaller than the magnetic resistance between the contact surface 1140 of the elongated member 110a and the contact surface 1140 of the elongated member 110b in the pipeline specimen 102. In this case, the magnetic flux can also be more reliably caused to flow from the surface of the pipeline specimen 102 to the elongated members.

[0069] The housing 104 can connect the extension 113 of the elongated member 110a and the extension 113 of the elongated member 110b. For example, the housing 104 can extend in the longitudinal direction of the elongated members 110a / b and be coupled to the extensions 113a / b to secure the elongated members 110a / b to each other. The housing 104 can be coupled to the extensions 113a / b using an adhesive or mechanical fasteners such as a strap or screws. The screws coupling the housing 104 and the extensions 113 can be made of a non-magnetic material so as not to interfere with the precision of the device 100.

[0070] The housing 104 can be positioned on the pipeline sample 102 side relative to the elongated members 110a / b. In this embodiment, as an example, the housing 104 is positioned between the extension 113 and the pipeline sample 102, with a gap provided between the housing 104 and the pipeline sample 102. However, the housing 104 can also be positioned on the opposite side of the elongated members 110a / b from the pipeline sample 102.

[0071] As in Figure 1 、 Figure 2 and Figure 5 As best understood, the first end 112a / b of the elongated member 110a / b includes a tapered portion 120a / b. The tapered portion 120a / b may have a shape that tapers as it approaches the gap 116. The tapered portion reduces the cross-sectional area of the elongated member 110a / b to the same or substantially the same area as the cross-sectional area of the sensor 108 on the magnetic field strength measuring device 106. For example, the area of the end surface of the elongated member 110a / b on the gap 116 side may be the same as the area of the sensor 108 on the magnetic field strength measuring device 106. This provides the additional benefit of amplifying the magnetic field intensity received by the sensor 108 on the magnetic field strength measuring device 106. The cross-sectional area of the narrow end of the elongated member is preferably slightly larger than that of the magnetic field sensor to prevent the sensor from being affected by edge effects of the elongated member, which may have a weaker magnetic field. This concentrates the magnetic field on a smaller cross-sectional area, resulting in a higher reading at the sensor 108 and increasing measurement accuracy. For example, by means of the tapered portion 120a / b, in a sensor 108 that is approximately 2 mm x 2 mm square, the area can be reduced to a square of approximately 3 mm x 3 mm. The depth of the gap 116 is approximately 1 mm, but it can also be a width that is at least sufficient to fit the sensor 108. The tapered portion 120a / b can be a different size depending on the size of the sensor 108. In the case where the elongated member 110a / b has a small cross-sectional area, sometimes no tapered portion is required. The shape of the tapered portion 120a / b in these figures should not be interpreted as a limiting shape. This is because the cross-sectional area can be reduced in any manner depending on the elongated member 110a / b.

[0072] Figures 1 to 3 and Figure 6 The illustrated magnetic field strength measurement device 106 may have a Hall Effect sensor. Figure 6 The circuit board shown is designed to place a Hall Effect sensor in the gap between the two long members of the bridge. The Hall Effect sensor generates a voltage slope that is directly proportional to the presence of a magnetic field. Therefore, the stronger the magnetic field, the greater the voltage output. Figures 1 to 3The illustrated magnetic field strength measurement device 106 is equipped with a plug-in terminal for connecting cables. These cables can be extended from the magnetic field strength measurement device 106 via a cable connector 122 to a control unit (not shown). The control unit receives voltage data from the Hall effect sensor and converts it into magnetic field strength data. Furthermore, the cables connecting to the magnetic field strength measurement device 106 can supply power to the magnetic field strength measurement device 106. This power can be supplied from any power source, such as a battery, or a thermal generator.

[0073] Furthermore, the device 100 can be permanently affixed to the sample 102. The device 100 can be affixed using an adhesive or mechanical fasteners such as straps or screws. When the device 100 is affixed to the sample 102 using screws, the magnetic permeability of the screws can be greater than or less than the magnetic permeability of the sample 102. For example, the screws can be formed from the same material as the sample 102 or from the same material as the elongated members 110a / b. Furthermore, the device 100 can be simply placed on the sample 102 without requiring any mounting hardware.

[0074] For example, if device 100 monitors magnetic flux through the steel wall of a submarine pipeline, multiple devices 100 can be attached to the pipeline at various locations. Multiple devices 100 can be attached to the pipeline in different orientations. Before deploying the pipeline, device 100 is attached to the pipeline and connected to an appropriate controller and power supply. Magnetic flux readings are taken at all locations, and all magnetic field strength measuring devices 106 are zeroed / calibrated. The pipeline is then deployed on the seabed. Over time, the interior of the pipeline corrodes and erodes, reducing the cross-sectional area or wall thickness of the pipeline. This reduction changes the magnetic field strength through the pipeline, and therefore the magnetic field strength through the elongated members 110a / b. To monitor the pipeline's condition, the electronics on device 100 can be switched periodically at regular intervals. This difference in magnetic field strength can then be correlated with a computer simulation model or experimental model to indicate the new wall thickness of the pipeline. This wall thickness provides a good indication of the pipeline's condition and the timing of potential pipeline replacement.

[0075] Alternatively, instead of switching the electronic devices on the apparatus 100, a transmitter (not shown) for transmitting the measurement data of the magnetic field strength measuring device 106 may be provided on the apparatus 100. The transmitter may be controlled by the aforementioned control unit. The transmitter may transmit data via wired communication or wireless communication. When the transmitter transmits data via wired communication, each apparatus 100 installed in the pipeline sample 102 may be connected to a relay device or a pipeline status monitoring device via a communication cable. When the transmitter transmits data via wireless communication, an unmanned submarine may patrol near each apparatus 100 and collect data.

[0076] The above example applies to a submarine pipeline. However, as will be readily apparent, the described apparatus 100 and method can be applied to any geometry or specimen that is not easily analyzed, for example, to surface pipelines and buried pipelines. Furthermore, the apparatus 100 can be retrofitted onto a specimen, for example.

[0077] Figure 4 Two devices 100 of the present invention are shown secured inside a casting 105. The casting 105 can be used in combination with the devices 100 to provide a data network. Figure 4 The casting 105 shown has the two devices positioned perpendicular to each other. This configuration provides both longitudinal and transverse readings of the magnetic field strength within the material. Device 100 can be configured in various directions to obtain magnetic field strength data in those directions. The example shown should not be construed as limiting, and other configurations are readily contemplated.

[0078] Figure 7 It is a graph showing the relationship between the magnetic field strength in the device of the present invention and the magnetic field strength in the sample being measured. The magnetic field strength through the magnetic field strength measuring device 106 (bridge) is represented on the X-axis, and the magnetic field strength through the sample 102 (pipe wall) is represented on the Y-axis, both of which are expressed in Gauss. The magnetic field strength inside the sample varies in different directions. For example, there may be a higher magnetic field strength in the long side direction of the sample than in the transverse direction. By using multiple devices, the magnetic field strength can be measured in all orientations and directions. The relationship between the magnetic field strength inside the sample and the magnetic field strength inside the long strip member is always proportional. Thus, the device can measure the magnetic field strength inside the sample in a non-destructive manner.

[0079] As shown, there is a positive proportional relationship between the magnetic field strength in magnetic field strength measurement device 106 (bridge) and specimen 102 (pipeline wall). The slope of the line in the graph is determined by the size and shape of device 100 and the size and shape of specimen 102. This is because the present invention is able to exploit this relationship. Because this relationship is linear, device 100 can continuously output accurate measurement values indefinitely. This relationship may not be linear, but may be any other type of proportional relationship. represents positive values of the magnetic field. However, if the magnetic field in the pipe wall is in a direction that is diametrically opposed, the measured magnetic field will be negative.

[0080] While specific embodiments of the present invention have been described above, it should be understood that deviations from the described embodiments are still within the scope of the present invention.

[0081] Description of Reference Numerals

[0082] 100 devices

[0083] 102 samples

[0084] 104 housing

[0085] 105 castings

[0086] 106 Magnetic Field Strength Measuring Equipment

[0087] 108 sensors

[0088] 110 long strip components

[0089] 112 end

[0090] 113 extension

[0091] 114 end

[0092] 116 Gap

[0093] 118 vertical axis

[0094] 120 tapered portion

[0095] 122 connection

[0096] 1140 contact surface

[0097] 1141 Standing Face

Claims

1. A device for measuring and / or monitoring the magnetic field strength inside a sample, the device comprising: A fixing unit made of non-magnetic material; A magnetic field strength measuring device having a sensor; as well as a first elongated member and a second elongated member, The first elongated member and the second elongated member are made of a material with high relative magnetic permeability, and the first elongated member and the second elongated member respectively have a first end and a second end. The fixing unit supports the first and second elongated members in a fixed posture so that the first end portion of the first elongated member and the first end portion of the second elongated member are positioned opposite to each other to form a gap. The magnetic field strength measuring device is embedded in the interior of the gap, The fixing unit is combined with the first elongated member and the second elongated member through a mechanical fixing member.

2. The device according to claim 1, characterized in that The first and second elongated members are respectively configured to be present on the surface of the sample or adjacent to the surface of the sample, and the first and second elongated members respectively have a longitudinal axis, and the center of the longitudinal axis is substantially consistent with the center of the longitudinal axis of the other elongated members.

3. The device according to claim 1, characterized in that The first ends of the first and second elongated members include tapered portions, thereby reducing the cross-sectional area of the first and second elongated members to substantially the same as the cross-sectional area of the sensor on the magnetic field intensity measuring device.

4. The device according to claim 2, characterized in that The first ends of the first and second elongated members include tapered portions, thereby reducing the cross-sectional area of the first and second elongated members to substantially the same as the cross-sectional area of the sensor on the magnetic field intensity measuring device.

5. The device according to any one of claims 1 to 4, characterized in that The first elongated member and the second elongated member each have a contact surface on a side closer to the second end than the first end, which is in surface contact with the sample.

6. The device according to claim 5, characterized in that The first elongated member and the second elongated member each have an extension portion extending away from the sample between the first end portion and the second end portion.

7. The device according to claim 6, characterized in that The closer to the first end, the farther the extension portion is from the sample.

8. The device according to claim 6, characterized in that The first and second elongated members are wider at the contact surface than at the extension portion.

9. The device according to claim 5, characterized in that The contact surface is curved in the width direction of the first elongated member or the second elongated member having the contact surface.

10. The device according to claim 5, characterized in that The contact surface is curved in the length direction of the first elongated member or the second elongated member having the contact surface.

11. The device according to claim 5, characterized in that The magnetic resistance between the contact surface of the first elongated member and the contact surface of the second elongated member in the device is smaller than the magnetic resistance between the contact surface of the first elongated member and the contact surface of the second elongated member in the sample.

12. The device according to any one of claims 1 to 4, characterized in that The test specimen was a metal conduit.

13. The device according to any one of claims 1 to 4, characterized in that The fixing unit is a housing.

14. The device according to claim 13, characterized in that The housing has at least one connection portion suitable for connecting a cable.

15. The device according to claim 13, characterized in that The housing and the first and second elongated members are mounted on the sample.

16. The device according to any one of claims 1 to 4, characterized in that The device further includes a transmitting unit for transmitting measurement data of the magnetic field strength measuring device.

17. The device according to any one of claims 1 to 4, characterized in that The magnetic field strength measuring device has a Hall effect sensor.

18. The device according to any one of claims 1 to 4, characterized in that The first elongated member and the second elongated member are made of a material having a low relative remanence of less than 100 microtesla.

19. The device according to any one of claims 1 to 4, characterized in that The magnetic field strength measuring device measures the magnetic field strength of about 0 to + / - 15000 Gauss.

20. The device according to any one of claims 1 to 4, characterized in that The magnetic permeability of the first elongated member and the second elongated member is higher than the magnetic permeability of the sample.

21. A method for measuring and / or monitoring the magnetic field strength inside a sample, the method comprising: The stage of installing or arranging the device according to any one of claims 1 to 20 on the sample; a stage of measuring the magnetic field strength passing through the first elongated member and the second elongated member using the magnetic field strength measuring device; as well as The stage of monitoring the value of the magnetic field strength passing through the sample by monitoring the value of the magnetic field strength passing through the first elongated member and the second elongated member.

22. The method according to claim 21, characterized in that The method further includes establishing a relationship between the magnetic field strength in the first and second elongated members and the magnetic field strength in the sample.

23. The method according to claim 21 or 22, characterized in that The stage of measuring and monitoring the magnetic field strength inside the sample is performed in order to monitor an area of a cross section of the sample.

24. The method according to claim 21 or 22, characterized in that By mounting the device on the sample in a state where the longitudinal axes of the first and second elongated members are aligned with the first axis of the sample, the magnetic field intensity passing through the sample is measured and monitored in the same direction as the first axis.

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