CLIAMS:1. A microwave reflectometry system, comprising:
a first probe;
a first insulation system configured to at least partially surround an electrically conductive conduit, wherein the first insulation system comprises an electrical insulating material, an electromagnetic insulating material, or a combination thereof; and
a circuitry configured to:
communicatively couple to the first probe, wherein the circuitry is configured to transmit a first signal via the first probe, wherein the first signal comprises a first unidirectional signal configured to traverse the electrically conductive conduit in a first direction based on the first insulation system; and to
apply a microwave reflectometry processing to a first reflective signal to derive a condition of the electrically conductive conduit, wherein the first reflective signal comprises a reflection of the first unidirectional signal based on the condition.

2. The system of claim 1, comprising a second probe configured to communicatively couple to the circuitry, wherein the first probe is configured to be positioned on the electrically conductive conduit on a first section of the electrically conductive conduit, wherein the second probe is configured to be positioned on the electrically conductive conduit on a second section of the electrically conductive conduit, wherein the first and second sections are on a same axis on opposite ends of the same axis, and wherein the first insulation system is configured to be positioned in-between the first and the second probe.

3. The system of claim 2, wherein the circuitry is configured to stop transmitting the first signal via the first probe and to transmit a second signal via the second probe, and wherein the second signal comprises a second unidirectional signal configured to traverse the electrically conductive conduit in a second direction opposite the first direction based on the first insulation system.

4. The system of claim 1, comprising a first matched impedance system configured to be disposed on the electrically conductive conduit adjacent the first insulation system, wherein the first matched impedance system is configured to minimize or eliminate reflective signals caused by the first unidirectional signal reflecting from the first insulation system.

5. The system of claim 4, wherein the first matched impedance system is configured to minimize or eliminate reflective signals caused by the first unidirectional signal reflecting off of the first insulation system by providing a matching impedance Zm.

6. The system of claim 5, wherein the first matched impedance system comprises a tunable impedance circuitry and a user interface configured to receive the Zm as an input, and wherein the first matched impedance system is configured to tune the tunable impedance circuitry to provide the matching impedance Zm.

7. The system of claim 1, comprising a second insulation system configured to at least partially surround an electrically conductive conduit, wherein the second insulation system comprises the electrical insulating material, the electromagnetic insulating material, or the combination thereof; and a multiplexer system comprising a switch electrically coupled to the electrically conductive conduit, wherein, wherein the a multiplexer system is configured to use the switch to bypass the first and the second insulation system to provide the first unidirectional signal and a second unidirectional signal, wherein the second unidirectional signal is configured to traverse the electrically conductive conduit in a second direction opposite the first direction based on the switch.

8. The system of claim 7, wherein the multiplexer system is included in the circuitry.

9. The system of claim 7, comprising a first and a second impedance matching systems configured to be disposed on the electrically conductive conduit between the first probe, wherein the first and the second impedance matching systems are configured to minimize or eliminate reflective signals caused by the first unidirectional signal reflecting from the first insulation system and from the second insulation system, respectively.

10. The system of claim 1, wherein the electrically conductive conduit comprises a pipeline system having a pipe, a first insulation layer surrounding the pipe, and a first cladding layer surrounding the first insulation layer, and wherein the first probe is configured to abut against the pipe.

11. A method for analyzing an electrically conductive conduit, comprising:
transmitting a first signal via a first probe disposed on an electrically conductive conduit, wherein the first signal comprises a first unidirectional signal configured to traverse the electrically conductive conduit in a first direction based on a first insulation system; and
applying a microwave reflectometry processing to a first reflective signal to derive a condition of the electrically conductive conduit, wherein the first reflective signal comprises a reflection of the first unidirectional signal based on the condition.

12. The method of claim 11, comprising electrically or electromagnetically insulating the electrically conductive conduit via the first insulation system configured to at least partially surround the electrically conductive conduit, wherein the first insulation system comprises an electrical insulating material, an electromagnetic insulating material, or a combination thereof, and wherein the insulating determines the first direction.

13. The method of claim 12, wherein electrically or electromagnetically insulating the electrically conductive conduit comprises electrically or electromagnetically insulating the electrically conductive conduit via the first insulation system and via a second insulation system, wherein the insulating via the first insulation system determines the first direction, and wherein the insulating via the second insulation system determines a second direction of travel opposite the first direction for a second unidirectional signal transmitted via the first probe.

14. The method of claim 11, comprising transmitting a second signal via a second probe disposed on the electrically conductive conduit, wherein the second signal comprises a second unidirectional signal configured to traverse the electrically conductive conduit in a second direction opposite the first direction.

15. The method of claim 11, comprising impedance matching a second reflective signal to minimize or eliminate the second reflective signal, wherein the second reflective signal is produced via a reflection of the first unidirectional signal caused by an insulation system.

16. The method of claim 11, wherein the microwave reflectometry processing comprises applying a time domain reflectometry (TDR) processing, a frequency domain reflectometry (FDR) processing, or a combination thereof, and wherien the condition comprises a moisture, a corrosion, or a combination thereof.

17. A microwave reflectometry system, comprising:
a processor configured to:
communicatively couple to a first probe, wherein the processor is configured to transmit a first signal via the first probe, wherein the first signal comprises a first unidirectional signal configured to traverse a electrically conductive conduit in a first direction based on a first insulation system; and to
apply a microwave reflectometry process to a first reflective signal to derive a condition of the electrically conductive conduit, wherein the first reflective signal comprises a reflection of the first unidirectional signal based on the condition.

18. The system of claim 17, comprising the first insulation system configured to at least partially surround the electrically conductive conduit, wherein the first insulation system comprises an electrical insulating material, an electromagnetic insulating material, or a combination thereof.

19. The system of claim 18, comprising a first matched impedance system configured to be disposed on the electrically conductive conduit adjacent the first insulation system, wherein the first matched impedance system is configured to minimize or eliminate reflective signals caused by the first unidirectional signal reflecting off of the first insulation system.

20. The system of claim 17, wherein the processor is configured to communicatively couple to a second probe, wherein the processor is configured to transmit a second signal via the second probe, wherein the second signal comprises a second unidirectional signal configured to traverse the electrically conductive conduit in a second direction opposite the first direction.
,TagSPECI:BACKGROUND
[0001] The subject matter disclosed herein relates to systems and methods for microwave reflectometry, and particularly to improved systems and methods for microwave reflectometry.
[0002] Microwave reflectometry techniques may generate signals and analyze signal reflections to determine certain conditions of a conduit carrying the signals. For example, certain equipment and facilities utilize metallic pipes or conduits to transport fluids over distances. However, moisture may traverse into the metallic pipe, leading to corrosion. Corrosion may degrade the structural integrity of the pipeline system. In some pipeline systems, the metallic pipe is insulated with a variety of shields and coverings, making the detection of moisture and/or corrosion difficult. For insulated, shielded pipes, visual inspection for corrosion on the outside of a shielded steel pipe may be impractical. Corrosion can also occur within a pipe. Visual inspection of the interior of the pipe is also very difficult. The need thus exists for improved systems and methods, including improved microwave reflectometry techniques, for inspecting for certain conditions and anomalies within a pipe system.

BRIEF DESCRIPTION
[0003] Certain embodiments commensurate in scope with the originally claimed invention are summarized below. These embodiments are not intended to limit the scope of the claimed invention, but rather these embodiments are intended only to provide a brief summary of possible forms of the invention. Indeed, the invention may encompass a variety of forms that may be similar to or different from the embodiments set forth below.
[0004] In one embodiment, a microwave reflectometry system includes a first probe and a first insulation system. The first insulation system is configured to at least partially surround an electrically conductive conduit, wherein the first insulation system comprises an electrical insulating material, an electromagnetic insulating material, or a combination thereof. The microwave reflectometry system further includes a circuitry configured to communicatively couple to the first probe, wherein the circuitry is configured to transmit a first signal via the first probe, wherein the first signal comprises a first unidirectional signal configured to traverse the electrically conductive conduit in a first direction based on the first insulation system. The circuitry is further configured to apply a microwave reflectometry processing to a first reflective signal to derive a condition of the electrically conductive conduit, wherein the first reflective signal comprises a reflection of the first unidirectional signal based on the condition.
[0005] In another embodiment, a method for analyzing an electrically conductive conduit includes transmitting a first signal via a first probe disposed on a electrically conductive conduit, wherein the first signal comprises a first unidirectional signal configured to traverse the electrically conductive conduit in a first direction. The method further includes processing a first reflective signal to derive a condition of the electrically conductive conduit, wherein the first reflective signal comprises a reflection of the first unidirectional signal based on the condition, and wherein the processing comprises applying a microwave reflectometry processing.
[0006] In yet another embodiment, a microwave reflectometry system includes a processor. The processor is configured to processor is configured to transmit a first signal via the first probe, wherein the first signal comprises a first unidirectional signal configured to traverse a electrically conductive conduit in a first direction. The processor is further configured to process a first reflective signal to derive a condition of the electrically conductive conduit, wherein the first reflective signal comprises a reflection of the first unidirectional signal based on the condition, and wherein the processing comprises applying a microwave reflectometry processing.

BRIEF DESCRIPTION OF THE DRAWINGS
[0007] These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
[0008] FIG. 1 is a perspective view diagram illustrating an embodiment of a pipeline system, including a microwave reflectometry system;
[0009] FIG. 2 is a block diagram of a side view of the pipeline system of FIG. 1 and a microwave reflectometry system suitable for bidirectional signaling;
[0010] FIG. 3 is a block diagram of a side view of the pipeline system of FIG. 1 and a microwave reflectometry system having two probes suitable for unidirectional signaling;
[0011] FIG. 4 is a block diagram of a side view of the pipeline system of FIG. 1 and a microwave reflectometry system having one probe suitable for unidirectional signaling; and
[0012] FIG. 5 is a flowchart illustrating an embodiment of a process useful in creating unidirectional signaling and impedance matching for observation of the pipeline system of FIG. 1.
DETAILED DESCRIPTION
[0013] One or more specific embodiments will be described below. In an effort to provide a concise description of these embodiments, not all features of an actual implementation are described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers’ specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
[0014] When introducing elements of various embodiments of the present invention, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.
[0015] Embodiments of the present disclosure may apply to systems and methods that use microwave reflectometry to detect unwanted conditions, such as pipe corrosion and/or excessive moisture. In one embodiment, a sensor assembly may transmit microwaves through a pipe and detect microwave reflections that may be due, for example, to corrosion and/or excessive moisture. In one embodiment, a pair of electrodes is mounted onto the pipe with a cladding discontinuity (e.g., electrical discontinuity) between the electrodes so that the waves only travel along one direction from each electrode. In another embodiment, a single electrode is mounted onto the pipe and two electrical discontinuities are placed on either side of the electrode. In this single electrode embodiment, a multiplexer may then be used to connect to only one cladding section at a time, thus providing for directional control of the microwaves.
[0016] Regardless of electrode configurations, the discontinuities may cause signal reflection from an abrupt termination of a wave path at the one or more discontinuities, such as discontinuities due to insulation systems. The techniques described herein may minimize or eliminate the discontinuity signal reflections by the inclusion of a matched impedance or microwave absorber so that minimal (or no) reflections are generated at the discontinuities. Accordingly, improved detection of certain pipe anomalies (e.g., corrosion, moisture) may be provided.
[0017] By way of introduction, and turning now to FIG. 1, the figure is a perspective view of an embodiment of pipeline system 10. In the depicted embodiment, the pipeline system 10 may include one or more pipes or conduits 12. The pipes 12 may include metallic pipes, such as pipe manufactured of electrically conductive materials (e.g., steel, steel alloys, iron, metallic alloys, and so on). In use, fluids such as liquids and/or gas may traverse through the pipes 12 to a variety of locations, including locations that may be geographically distant from one another. Indeed, the pipe 12 may traverse hundreds or even thousands of kilometers. The pipe 12 may be buried underground or otherwise disposed in certain environments, where moisture or other undesired conditions may be present. Accordingly, certain conditions 14, 16 may arise on a metallic outer surface 18 of the pipe 12. For example, excessive moisture 14 and/or corrosion 16 may develop over time.
[0018] The pipe 12 may additionally be covered or cladded with certain material (shown in more detail below with respect to FIG. 2), making the detection of the anomalies 14, 16 more difficult. The techniques described herein provide for a microwave reflectometry system, such as a vector network analyzer (VNA) system 20 that includes certain microwave reflectometry techniques useful in detecting the anomalies 14, 16. In the example depicted in FIG. 1, the VNA system 20 may include one or more probes 22. The probes 22 may transmit signals into the conduit or pipe 12 as well as receive signals from the conduit or pipe 12, thus providing for both electrode and antenna functionality. The probe 22 may be inserted into the pipe 12 via an access port 24 and/or via an opening in the pipe 12. In use, the VNA device 20 may electrically excite the probe 22, causing signals 26 and 28 (e.g., electromagnetic waves such as microwaves) to traverse outwardly from about a probe insertion line 30. The signals 26, 28 may be unidirectional, thus traveling towards only one side of the pipe 12.
[0019] As the electromagnetic waves 26 and 28 traverse the pipe 12, the electromagnetic waves 26 and 28 may encounter the conditions 14 and 16, respectively. The encounter may result in reflective electromagnetic waves 32, 34 reflecting from the conditions 14 and 16. The reflective electromagnetic waves 32 and 34 may then be detected via the probe 22 and communicated to a VNA circuitry 36, such as a data acquisition (DAQ) and data analysis circuitry 36. In certain embodiments, the VNA circuitry 36 may include one or more processors 38 and a memory 40. The processors 38 may execute computer instructions stored in the memory 40, such as instructions that transmit signals resulting in the waves 26, 28 and then analyze signals, e.g., the reflective electromagnetic waves 32, 34, to derive the existence of the conditions 14, 16.
[0020] For example, the VNA circuitry 36 may apply time domain reflectometry (TDR) and/or frequency domain reflectometry (FDR) to the signals 26, 28, 32, 34 transmitted and/or received via the probe 22 to derive the existence of the conditions 14, 16. In one example, a fast rise time pulse or spectrum of electromagnetic waves (e.g., microwaves at approximately between 0.1 GHz to 2GHz) may be launched down a transmission line structure (e.g., the pipe 12), and the reflections (e.g., reflective waves 32, 34) that occur from changes in the characteristic impedance of the transmission line structure are measured (e.g., measured via the probe 22). The magnitude and polarity of the reflections 32, 34 can be related to physical parameters of the structure and deviations from nominal may be detected, thus enabling the derivation of the conditions 14, 16. It is to be noted that while FIG. 1 illustrates a hollow pipe 12, the techniques described herein may be applicable to a variety of transmission line structures including solid conduits, tubular and non-tubular pipes, spans, and so on.
[0021] FIG. 2 is a cross sectional block view depicting an embodiment of a VNA system 20 disposed on the pipeline system 10. In the depicted embodiment, the pipeline system 10 includes the pipe 12 surrounded by an insulation layer 50 and a cladding layer 52. While the depicted embodiment shows one insulation layer 50 and one cladding layer 52, other embodiments may include multiple insulation layers 50 and/or multiple cladding layers 52. The illustrated embodiment shows the insulation layer 50 as being a mineral wool layer, but other insulative materials may be used, including fiberglass layers, polymer layers, and so on. Likewise, the illustrated embodiment shows the cladding layer 50 as being an aluminum cladding layer, but other cladding material may be used, such as other metallic and/or non-metallic cladding material.
[0022] The pipe 12 includes a pipe diameter Dp, the insulative layer 50 includes a thickness Ti, and the cladding layer includes a thickness Tc. Accordingly, a diameter of the pipeline system 10 may be computed as Dp + 2Tc + 2Ti. Also shown is a sensor assembly section 56 of the VNA system 20 that includes a spool assembly 58. The spool assembly 58 is depicted as surrounding the pipe 12 and having the probe 22 disposed to abut against the outer surface 18 of the pipe 12. The spool assembly 58 may further include an insulative layer 60, such as a Teflon™ layer, and a cladding layer 62, such as a steel cladding layer. The probe 22 may be communicatively coupled to the VNA circuitry 36 via an electrical conduit 64. In other embodiments, the VNA circuitry 36 may be wirelessly communicatively coupled to the probe 22, for example, via Bluetooth, WiFi, and so on.
[0023] In use, the VNA circuitry 36 (e.g., the processor 38 executing instructions stored in the memory 40) may command that the probe 22 transmit an electromagnetic signal 66. In the depicted embodiment, the electromagnetic signal 66 may bidirectionally emanate from the approximate midline 30 through the pipe 12. Accordingly, the same bidirectional signal 66 may travel towards end 68 and also towards end 70 of the pipe 12. As the bidirectional signal 66 travels towards end 68, the signal 66 may encounter the moisture 14, producing reflective signal 32. The reflective signal 32 may then reflect back into the probe 22. Likewise, as the bidirectional signal 66 travels towards end 70, the signal 66 may encounter the corrosion 16, producing reflective signal 34. The reflective signal 34 may then reflect back into the probe 22.
[0024] The probe 22 may then transmit the signals 32, 34 for processing via the VNA circuitry 36. The VNA circuitry 36 may derive that the moisture 14 and/or corrosion 16 are present. However, because the embodiment of the VNA system 20 depicted in FIG. 2 uses the bidirectional signal 66 to traverse towards both ends 68 and 70, extra processing may be used to derive the direction of the reflective signal 32 and/or the signal 34. Also, the bidirectional signal 66 may not travel as far when compared to a unidirectional signal. Advantageously, the techniques described herein provide for unidirectional signaling via one, two, or more probes 22, as described in more detail below.
[0025] FIG. 3 a cross sectional block view depicting an embodiment of a VNA system 20 disposed on the pipeline system 10 suitable for unidirectional signaling. In the depicted embodiment, the spool assembly 58 may include two probes 22. Each of the probes 22 may be communicatively coupled to the VNA circuitry 36 via corresponding electrical conduits 64. Wireless conduits may additionally be used to communicatively couple the probes 22 to the VNA circuitry 36, such as via Bluetooth, WiFi, and so on. Also shown is the insulative layer 60, and the cladding layer 62. In the depicted embodiment, one or more insulation systems 80 may be disposed to completely or partially surround the pipe 12, thus electrically or electromagnetically apportioning the spool assembly 58 into sections 82 and 84. The insulation system(s) 80 may include, for example, rings or partial ring structures having electric and/or electromagnetic insulation suitable to prevent crosstalk between the two sections 82 and 84. For example, the insulation system(s) 80 may include metallic structures, dielectric materials, shielded cables, metallic meshes, and so on, suitable for electromagnetically or electrically insulating 82 from portion 84, and vice versa, by contacting the pipe 12. In one embodiment, the probes 22 may contact the pipe 12 to transmit and receive signals. In another embodiment, the probes 22 may not contact the pipe 12, and instead, wirelessly excite signals in the pipe 12 to transmit, and/or wireless receive signals reflecting through the pipe 12, e.g., via electromagnetic pulses.
[0026] In use, signals 86 produced by the first probe 22 disposed towards the pipe end 68 may be blocked by the insulation system 80 from traveling towards the pipe end 70. Accordingly, the signals 86 may travel in a unidirectional manner towards the pipe end 68. Likewise, signals 88 produced by the second probe 22 disposed towards the pipe end 70 may be blocked by the insulation system 80 from traveling towards the pipe end 68. Accordingly, the signals 88 may travel in a unidirectional manner towards the pipe end 70. By providing for unidirectional signals 86, 88, the techniques described herein may enable more efficient processing (e.g., TDR and/or FDR processing) because directions of reflecting signals, such as the signals 32, 34, are known a priori. For example, the first probe 22 disposed towards the pipe end 68 may expect reflecting signals incoming from pipe end 68. Similarly, the second probe 22 disposed towards the pipe end 70 may expect reflecting signals incoming from pipe end 70. Additionally, because the signals 86, 88 may now travel unidirectionally, the signals 86, 88 may traverse farther through a length of the pipe 12 as compared to the bidirectional signal 66.
[0027] There may be a certain amount of reflectivity of waves due to the insulation system 80, such as reflective waves or signals 90, 92 reflecting from the insulation system 80. In order to minimize or eliminate the reflective signals 90, 92 caused by the insulation system 80, the techniques described herein may include a matched impedance system 94. The matched impedance system 94 may be provided to include reflection-less matching techniques based on certain characteristics of the pipeline system 10, including the sensor assembly 56. For example, the type of material of the pipe 12, the insulative layer 50, and the cladding layer 52 may be used to provide a matched impedance via the matched impedance system 94. Likewise, the sizes (e.g., diameter Dp, thickness Ti, Tc) of the pipe 12, the material of insulative layer 50 and of the cladding layer 52 may be used to provide the matched impedance via the impedance system 94. Additionally, the material types and sizes of the various components of the spool assembly 58 (e.g., probe 22, insulation system(s) 80, cladding 62) may be used to provide the matched impedance via the matched impedance system 94. Similarly, the frequencies and/or power of the signals 86, 88 may be used to provide the matched impedance via the matched impedance system 94.
[0028] In one embodiment, the matched impedance system 94 may include electrical and/or electronic components (e.g., resistors, capacitors, diodes, and so on) suitable for providing for a matched impedance Zm, where Zm is equal to the impedance Zs of the pipeline system 10, including the spool assembly 58 (e.g., probe 22, insulation system(s) 80, cladding 62). Other embodiments may include tunable circuitry embodiments where the matched impedance system 94 may include a user interface enabling a user to enter the aforementioned characteristics of the pipeline system 10 and spool assembly 58 (e.g., material types, sizes, signal 86, 88 frequencies), or a value for Zs. The matched impedance system 94 may then tune impedance circuitry based on the user input to provide for the impedance Zm that matches Zs. With Zm = Zs, reflection signals 90, 92 may be minimized or eliminated. In one embodiment, the tunable matched impedance system 94 may include a digital controlled potentiometer (DCP) system whose internal resistance may be tuned digitally, such as a DCP system available from Intersil Corporation, of Delaware, U.S.A., as model number ISL233x5. Digitally tuning of the DCP may thus provide for the desired impedance (e.g., alternating current resistance).
[0029] It is to be noted that while the VNA system 20 shown in FIG. 3 illustrates a single VNA circuitry 36 communicatively coupled to the first and the second probes 22, other embodiments may include two VNA circuitries 36, a first and a second VNA circuitries 36. The first VNA circuitry 36 may be communicatively coupled to the first probe 22 and the second VNA circuitry 36 may be communicatively coupled to the second probe 22. Adding multiple VNA circuitries 36 may further speed up processing of signals 86, 88.
[0030] In other embodiments, such as the embodiment depicted in FIG. 4, a single probe 22 may be used in conjunction with a multiplexer system to provide for the unidirectional signals 86, 88. More specifically, FIG. 4 is a cross sectional block view depicting an embodiment of the VNA system 20 disposed on the pipeline system 10 having a single probe 22 and a multiplexer system 100 suitable for unidirectional signaling. Because the figure includes like elements as those in FIG. 3, the like elements are shown with like numbers. In the depicted embodiment, the spool assembly 58 includes the single probe 22 communicatively coupled to the VNA circuitry 36 via electrical conduits 64. Wireless conduits may additionally be used to communicatively couple the probe 22 to the VNA circuitry 36. Also shown is the insulative layer 60, and the cladding layer 62. In one embodiment, the probe 22 may contact the pipe 12 to transmit and receive signals. In another embodiment, the probe 22 may not contact the pipe 12, and instead, wirelessly excite signals in the pipe 12 to transmit, and/or wireless receive signals reflecting through the pipe 12, e.g., via electromagnetic pulses.
[0031] In the depicted embodiment, two insulation sets, each set having one or more insulation systems 80, may be disposed to completely or partially surround the pipe 12 at opposite ends of the probe 22. A first set of insulation systems 80 may be disposed towards the pipe end 68, and a second set of insulation systems 80 may be disposed towards the pipe end 70. As mentioned above insulation system(s) 80 may include electric and/or electromagnetic insulation suitable for preventing the traversal of signals delivered via the probe 22. For example, the insulation system(s) 80 may include metallic structures or rings, dielectric materials, shielded cables, metallic meshes, and so on, suitable for electromagnetically or electrically insulating 82 from portion 84, and vice versa. Each of the first and second set of insulation systems 80 may be bypassed by the multiplexer 100 via electrical conduits 103, 105, and 107. Each of the conduits 103, 105, and 107 may be coupled to the cladding 62. Because the cladding 62 in the depicted embodiment is electrically conducting cladding and is contacting the probe 22, signals from the probe 22 may traverse through the cladding 62 into the conduit 107, e.g., when the probe 22 is operating as an electrode. Likewise, signals from the conduit 107 may traverse into the cladding 62 and then into the probe 22, e.g., when operating as an antenna. However, the first and the second insulation systems 80 prevent probe 22 signals from entering conduits 103, 105 directly, and such signals may only enter or leave the conduits 103, 105 via the multiplexer 100. Signals into the conduits 103 and 105 are thus gated via the multiplexer 100.
[0032] In use, the multiplexer 100 may switch so that the first and the second insulation systems 80 are set “on” and “off.” When turned “on”, the insulation systems 80 may provide for electric and/or electromagnetic insulation, while when turned “off”, the insulation systems 80 may allow the traversal of electricity and/or magnetism. Accordingly, if the signal 86 is desired, the second set of insulation systems 80 disposed towards the pipe end 70 may be turned “on” while the first set of insulation systems 80 disposed towards the pipe end 68 may be turned “off.” The signal 86 may then unidirectionally travel towards the pipe end 68. Likewise, if the signal 88 is desired, the first set of insulation systems 80 disposed towards the pipe end 68 may be turned “on” while the second set of insulation systems 80 disposed towards the pipe end 70 may be turned “off.” The signal 88 may then unidirectionally travel towards the pipe end 70. Indeed, by multiplexing the insulation systems 80, the techniques described herein may provide for unidirectional signaling via a single probe 22.
[0033] Turning “off” the insulation system 80 may involve electronically and/or mechanically bypassing the insulation system 80. For example, a switch 109 of the multiplexer 100 may disconnect a terminal 111 and connect a terminal 113, as depicted. Accordingly, current flowing from the probe 22 may now flow through conduit 107 and into conduit 105, thus bypassing the insulation system 80 disposed towards the pipe end 70. The electricity may then continue flowing as the signal 88 unidirectionally towards the pipe end 70. Incoming signal 34 may then enter through conduit 105, traverse the switch 109 into conduit 107, and then into probe 22. When the pipe towards end 68 is inspected, the switch 109 may disconnect terminal 113 and connect terminal 111. Accordingly, signals from the probe 22 may traverse conduit 107 into conduit 103 and propagate down the pipe 12 as the signal 86 unidirectionally towards the pipe end 68. Incoming signals 32 may then enter through conduit 103, traverse the switch 109 into conduit 107, and then into probe 22. In this manner, the multiplexer 100 may turn the first and/or the second insulation systems 80 “on” or “off.” Additionally or alternatively, the insulation systems 80 may be turned “on” or “off” mechanically. For example, an actuator may be used to mechanically move the system 80 so that no contact is made with the pipe 12.
[0034] Also shown are two matched impedance systems 94, useful in minimizing or eliminating reflective waves caused by the insulation systems 80. The first matched impedance system 94 is shown disposed towards the pipe end 68 side of the probe 22, the second matched impedance system 94 is shown disposed towards the pipe end 70 side of the probe 22. In use, when the first set of the insulation systems 80 (e.g., disposed towards the pipe end 68) is providing insulation, thus enabling the unidirectional signal 88, reflective waves 104 caused by the first set of the insulation systems 80 may be created. The reflective waves 104 may be minimized or eliminated by the first matched impedance systems 94. Likewise, when the second set of the insulation system 80 (e.g., disposed towards the pipe end 70) is providing insulation, thus enabling the unidirectional signal 86, reflective waves 106 caused by the second set of the insulation systems 80 may be created. The reflective waves 106 may be minimized or eliminated by the second matched impedance systems 94.
[0035] As described earlier, each of the two matched impedance systems 94 may provide for the impedance Zm designed to match the impedance Zs of the pipeline system 10 and the spool assembly 58. In the depicted embodiment, the spool assembly 58 includes the two sets of insulation systems 80 and the single probe 22, and thus, the value of Zm and Zs for the embodiment shown in FIG. 4 may likely be different than the value of Zm and Zs for the embodiment shown in FIG. 3. It is also to be noted that, in certain embodiments, the multiplexer 100 may be a component of the VNA circuitry 36, and thus controllable via the processor 38. By providing for the single probe 22 suitable for unidirectional signaling, the techniques described herein may provide for more efficient and accurate detections of pipe conditions 14, 16.
[0036] FIG. 5 is a flow chart of an embodiment of a process 200 suitable for observing, for example, the pipeline system 10 via unidirectional signaling. The process 200 may be implemented as computer-executable code or instructions executable via the processor 38 and stored in the memory 40. In the depicted embodiment, a unidirectional signal, such as signals 86 and/or 88 may be generated, for example, by applying certain microwave reflectometry techniques, including time domain reflectometry (TDR) and/or frequency domain reflectometry (FDR) techniques. As mentioned previously, the signals 86 and/or 88 may be generated (block 202) to traverse an electrical conduit (e.g., pipeline system 10) unidirectionally via the insulation systems 80. For example, two of the probes 22 may be used, as described above with respect to FIG. 3, and/or a single probe 22 may be used, as described above with respect to FIG. 4.
[0037] Unwanted reflections, for example, caused by the insulation system(s) 80 may be ameliorated or removed by applying matched impedance (block 204), for example, via the matched impedance system(s) 94. The resulting return signals caused by certain conditions (e.g., reflected waves that reflect because of the conditions such as moisture 14 and/or corrosion 16) may then be received via the one or more probes 22 and further processed (block 206), for example, by applying TDR and/or FDR techniques, to derive the conditions of the pipeline system 10 (block 208), such as the moisture 14 and/or the corrosion 16. By applying unidirectional signaling and impedance matching, the techniques described herein may enable a more optimal use of signals, which may travel further through the pipeline system 10.
[0038] Technical effects of the invention include providing for one or more probes combined with electrical or electromagnetic insulation to transmit signals in one direction through a conduit (e.g., unidirectional transmission). The technical effects further include applying impedance matching suitable for minimizing or eliminating reflective waves that may reflect due to the electrical or electromagnetic insulation, thus providing for a cleaner signal that may more optimally be used to detect a variety of conduits of the conduit.
[0039] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.