Tool for verifying thermal conductivity measurements of a heat flow probe

Abstract

A tool and method for verifying thermal conductivity measurements of a heat flow probe are disclosed. The tool comprises a first part comprising a first recess for receiving the heat flow probe The first part comprises a first ceramic or glass material. The tool comprises a second part comprising a second recess for receiving the heat flow probe. The second part comprises a second ceramic or glass material. The first part and the second part are movable relative to one another between an open position in which the heat flow probe can be inserted into one or more of the first recess and the second recess and a closed position in which the first recess and the second recess form a cavity for enclosing at least a portion of the heat flow probe. Unlocking insights from geodata, the present disclosure further relates to improvements in sustainability and environmental developments: together we create a safe and liveable world.

Description

TOOL FOR VERIFYING THERMAL CONDUCTIVITY MEASUREMENTS OF A HEAT FLOW PROBEFIELD

[0001] The present disclosure relates generally to a tool for verifying thermal conductivity measurements of a heat flow probe. More particularly, the disclosure relates to a tool with components of known thermal conductivity that can be used as a reference material for verifying thermal conductivity measurements of a heat flow probe. Unlocking insights from Geo-Data, the present invention further relates to improvements in sustainability and environmental developments: together we create a safe and liveable world.BACKGROUND

[0002] There is a general and ongoing need to improve data acquisition of subsurface surveying. The determination of subsurface characteristics is used to identify objects below the surface of the ground, as well as determining the soil characteristics, such as soil type, density, moisture content, shear modulus, and the like, which may be used in foundation planning and / or management. Subsurface information may be used for e.g., site characterisation for infrastructure projects, foundation calculations, and the like. For such applications, it is important to generate a comprehensive understanding of the subsurface with a high degree of accuracy in an efficient manner.

[0003] There is a need to determine thermal characteristics of the soil. One such characteristic is thermal conductivity of the soil, which provides a measure of energy dissipation through soil. The thermal conductivity of a material is a measure of its ability to conduct heat and is defined as the transport of energy due to random molecular motion across a temperature gradient. This is an important characteristic to determine since it influences fundamental aspects of infrastructure construction and other subsurface activities, such as foundation design, cable routing and cable design, insulation properties of subsurface structures, and the like. The measure of heat conduction also influences, for example, how fast heat produced in power and / or data cables can dissipate so as to stop such cables from overheating. Optimal cable routing may also be influenced by a measure of heat dissipation such that a route is chosen in which the thermal conductivity of the soil does not negatively influence the operating characteristics of the cable. Thermal characteristics of the soil may be similarly relevant for other applications.

[0004] A heat flow probe is defined as any probe that can be used to determine thermal conductivity. An example of a heat flow probe is a probe that can be inserted into the ground, for example, using a pushrod or other insertion means. Once inserted into the ground, the heat flow probe is actively heated to a desired temperature difference, at which point heating is stopped. The heat flow probe then gives off heat to the surrounding soil as the temperature of the heat flow probe is higher than the temperature of the surrounding soil. The speed with which the temperature of the heat flow probe reduces is indicative of the thermal conductivity of the soil surrounding the heat flow probe. If the soil has a higher thermal conductivity, the heat dissipates at a higher rate, leading to a higher average temperature differentialand as a result a higher reduction of temperature of the heat flow probe. A thermometer is generally positioned in the heat flow probe, which measures the decrease of the temperature after the heat flow probe has been heated to the desired temperature.

[0005] In more detail, the rate of dissipation of thermal energy through the soil, i.e., thermal conductivity, determines the speed with which the temperature gradient between the heat flow probe and the soil is reduced. If the soil heats up but cannot dissipate the energy quickly, the temperature of the soil directly surrounding the heat flow probe will rise, such that the temperature differential between the heat flow probe and the soil is reduced and the rate of the temperature reduction of the heat flow probe flattens. As a result, the temperature decline of the heat flow probe is less steep, providing information on a low thermal conductivity of the soil. Similarly, if the rate at which the energy dissipates is very high, i.e., the rate of temperature reduction ofthe heat flow probe is high, the thermal conductivity of the surrounding soil is high.

[0006] Heat flow probes can come in various shapes and sizes, depending on the specific application. For example, needle probes are often used for measurements in softer soils. These probes are typically long and thin and can be inserted into the material with relative ease. Larger diameter and more robust probes may be used for measurements in harder soils.

[0007] Regardless of the specific type of heat flow probe used, it is desirable to verify the accuracy of the probe's thermal conductivity measurements. This is typically done by comparing the heat flow probe's measurement output when testing reference materials with known values of thermal conductivity. The reference materials used should cover the range of expected thermal conductivity values measured in the field. For example, the range of expected thermal conductivity measurement values includes 0.4-1 .5 W / mK for peat at the lower end, 0.8-2.5 W / mK for clay and 1.8-3.2 W / mK for sand at the high end. Dry sand can have a thermal conductivity below 0.5 W / mK.

[0008] Finding suitable reference materials can prove challenging, particularly for materials with high thermal conductivity values and particularly for larger diameter probes. There is a need for improved tools for verifying thermal conductivity measurements.SUMMARY

[0009] This summary introduces concepts that are described in more detail in the detailed description. It should not be used to identify essential features of the claimed subject matter, nor to limit the scope of the claimed subject matter.

[0010] According to a first aspect ofthe present disclosure, there is provided a tool for verifying thermal conductivity measurements of a heat flow probe. In some example implementations, the tool may be suitable for verifying thermal conductivity measurements of a probe capable of measuring. In some example implementations, the tool comprises a first part comprising a first recess for receiving the heat flow probe. In some example implementations, the first part comprises a material with a thermal conductivity greater than 1 W / mK. In some example implementations, the first part comprises a material with a thermal conductivity within the rage of 1 .8 to 3.2 W / mK. In some example implementations, the first part comprises a first ceramic or glass material.

[0011] In some example implementations, the tool comprises a second part comprising a second recess for receiving the heat flow probe. In some example implementations, the second part comprises a material with a thermal conductivity greater than 1 W / mK. In some example implementations, the fecund part comprises a material with a thermal conductivity within the rage of 1 .8 to 3.2 W / mK. In some example implementations, the second part comprises a second ceramic or glass material.

[0012] In some example implementations, the first part and the second part are movable relative to one another between an open position in which the heat flow probe can be inserted into one or more of the first recess and the second recess and a closed position in which the first recess and the second recess form a cavity for enclosing at least a portion of the heat flow probe.

[0013] In some example implementations, the cavity for enclosing at least a portion of the heat flow probe define a cylindrical space. In some example implementations, the first and second recesses define a demi-cylindrical space. As such, the first and second recesses together define the cylindrical cavity for enclosing at least a portion of the heat flow probe. It is known in the art that the shape of a probe, such as a heat flow probe, has a substantially circular cross-section. At least a portion of the heat flow probe thus also defines a cylindrical space. The cavity arranged for enclosing at least a portion of the heat flow probe thus also is cylindrical.

[0014] Advantageously, a close fit with the heat flow probe is facilitated by the arrangement of the tool, improving the accuracy of verification. The moveable arrangement of the first part and the second part also facilitates easier alignment of tool with the heat flow module of the heat flow probe. Using a ceramic or glass material as reference materials permits verification of the tool for thermal conductivity values above 1 W / mK.

[0015] In some example implementations, the first part and the second part are coupled to permit the relative movement of the first part and the second part between the open position and the closed position, optionally, wherein the first part and the second part are coupled via a pivotable coupling. Advantageously, the optionally pivotable coupling facilitates more reliable alignment of tool with the heat flow module of the heat flow probe.

[0016] In some example implementations, the first part comprises a first plurality of ceramic or glass segments, optionally, wherein the first plurality of ceramic or glass segments are adhered to one another. Advantageously, this segmentation permits tools of a larger size to be manufactured from glass or ceramic, in spite of the limitations of manufacturing reference materials with these objects.

[0017] In some example implementations, the first plurality of ceramic or glass segments each have a thickness in at least one direction of 40mm or less, optionally, wherein the wherein the first plurality of ceramic or glass segments each have a thickness of 40mm or less in any or every direction. This ensures that the ceramic can be fully cured when manufactured, improving the mechanical and thermal performance of the ceramic.

[0018] In some example implementations, the tool comprises a first frame, wherein the first part is coupled to the first frame via a first coupling.

[0019] In some example implementations, The first coupling is configured to permit movement of the first part relative to the first frame. This enables self-alignment of the ceramic segments. It also provides a margin that compensates for manufacturing tolerances.

[0020] In some example implementations, the first coupling comprises a first pin running through the first part.

[0021] In some example implementations, the first pin engages corresponding orifices in the first frame such that movement of the first pin relative to the first frame is permitted.

[0022] This enables self-alignment of the ceramic segments. It also provides a margin that compensates for manufacturing tolerances.

[0023] In some example implementations, the first frame comprises a handle for facilitating movement of the tool between the open and closed positions. The handle enables the tool to be opened and closed more easily.

[0024] In some example implementations, the first part and / or the second part comprises a flow path for supplying a thermally conductive compound to an outer surface of the heat flow probe when the tool is in the closed position. This facilitates accurate administering of a thermal past to the outside of the heat flow probe, resulting in improved accuracy in the verification process.

[0025] In some example implementations, the second part comprises a second plurality of ceramic or glass segments, optionally, wherein the first plurality of ceramic or glass segments are adhered to one another. This segmentation permits the provision of a tool of the required size due to ceramic manufacturing limitations.

[0026] In some example implementations, the second plurality of ceramic or glass segments each have a thickness in at least one direction of 40mm or less, optionally, wherein the wherein the first plurality of ceramic or glass segments each have a thickness of 40mm or less in any or every direction. Advantageously, this segmentation permits tools of a larger size to be manufactured from glass or ceramic, in spite of the limitations of manufacturing reference materials with these objects.

[0027] In some example implementations, the tool further comprises a second frame, wherein the second part is coupled to the second frame via a second coupling.

[0028] In some example implementations, the second coupling is configured to permit movement of the second part relative to the second frame. This enables self-alignment of the ceramic segments. It also compensates for manufacturing tolerances.

[0029] In some example implementations, the second coupling comprises a second pin running through the second part.

[0030] In some example implementations, the second pin engages corresponding orifices in the second frame such that movement of the second pin relative to the second frame is permitted.

[0031] In some example implementations, the second frame comprises a base of the tool. The base provides for stability of tool so that it can be opened and closed more easily.

[0032] In some example implementations, the cavity formed by the first recess and the second recess, when in the closed position. In some example implementations, the cavity has a diameter greater than or equal to 44 mm. In some example implementations, the cavity has a diameter of any value between 15 mm and 60 mm, for example 25.5 mm, 36 mm or 44 mm, or greater than each of these values.

[0033] In some example implementations, the first recess and / or the second recess are configured to conform to the contours of an outer surface of the heat flow probe. A closer fit with the probe is provided, facilitating more accurate verification.

[0034] In some example implementations, the first ceramic material and / orthe second ceramic material comprise Zirconia TZP. Zirconia TZP provides optimum performance of the verification process. And its thermal properties are isotropic (same in all directions). It also does not corrode, and is resistant to wear due to its hardness, so it is durable.

[0035] In some example implementations, the first ceramic or glass material and / or the second ceramic or glass material have a thermal conductivity above 1 W / mK.

[0036] In some example implementations, the first ceramic or glass material and / or the second ceramic or glass material has a thermal conductivity within the rage of 1 .8 to 3.2 W / mK.

[0037] In some example implementations, the first ceramic or glass material and / or the second ceramic or glass material comprise the same material.

[0038] In some example implementations, the tool further comprises at least one damper configured to dampen relative movement of the first part and the second part when moving from the open position to the closed position.

[0039] According to a second aspect of the present disclosure, there is provided a method of verifying thermal conductivity measurements of a heat flow probe. In some example implementations, the method comprises inserting the heat flow probe into the tool of any preceding claim when the tool is in the open position. In some example implementations, the method comprises moving the tool to the closed position in which at least a portion of the heat flow probe is enclosed by the first part and the second part. In some example implementations, the method comprises obtaining a thermal conductivity measurement from the heat flow probe In some example implementations, the method comprises comparing the thermal conductivity measurement with a known value of the thermal conductivity of the first part and / or the second part.

[0040] According to a third aspect of the present disclosure, there is provided a component for use in a tool for verifying thermal conductivity measurements of a heat flow probe, the component having the features of the first part or the second part of the first aspect.

[0041] According to a fourth aspect of the present disclosure, there is provided a system comprising a heat flow probe the tool of the first aspect.

[0042] A heat flow probe is defined as any probe that can be used to determine thermal conductivity. As outlined above, an example of a heat flow probe is a probe that can be inserted into the ground, for example, using a pushrod or other insertion means. Once inserted into the ground, the heat flow probe is actively heated to a desired temperature difference and the speed at which it heats up can be measured and is indicative of the thermal conductivity of the soil surrounding the heat flow probe. Once heating is stopped, the heat flow probe then gives off heat to the surrounding soil as the temperature of the heat flow probe is higher than the temperature of the surrounding soil. The speed with which the temperature of the heat flow probe reduces is also indicative of the thermal conductivity of the soil surrounding the heat flow probe. If the soil has a higher thermal conductivity, the heat dissipates at a higher rate, leading to a higher average temperature differential and as a result a higher reduction of temperature of the heat flow probe. A thermometer is generally positioned in the heat flow probe, which measures the increase and / or decrease of the temperature after the heat flow probe has been heatedto the desired temperature. This is merely an example implementation of a heat flow probe and any probe that can be used to determine thermal conductivity can be considered a heat flow probe.

[0043] It will be understood that where reference is made to a heat flow probe herein, this could be any probe capable of making a thermal conductivity measurement.BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to describe the manner in which the above-recited and other advantages and features of the disclosure can be obtained, a more particular description of the principles briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only exemplary implementations of the disclosure and are therefore not to be considered to be limiting of its scope, the principles herein are described and explained with additional specificity and detail through the use of the accompanying drawings in which:

[0045] FIG. 1 shows a side view of the heat flow probe, in accordance with the present disclosure;

[0046] FIG. 2 shows a cut-out view of the heat flow probe, in accordance with the present disclosure;

[0047] FIG. 3 shows a three-dimensional view of the inner sleeve of a heat flow module in the heat flow probe, in accordance with the present disclosure;

[0048] FIG. 4 shows a three-dimensional cross-sectional view of a section of the heat flow probe, in accordance with the present disclosure, showing a heat flow module;

[0049] FIG. 5 shows a tool for verifying thermal conductivity measurements functionality of a heat flow probe in an open position, in accordance with the present disclosure;

[0050] FIG. 6 shows the tool of FIG. 5 in a closed position, in accordance with the present disclosure;

[0051] FIG. 7 shows a first part of the tool of FIGS. 5 and 6, in accordance with the present disclosure;

[0052] FIG. 8 shows a side view of the tool of FIGS. 5, 6 and 7, in accordance with the present disclosure;

[0053] FIG. 9 shows a front view of the tool of FIGS. 5, 6, 7 and 8, in accordance with the present disclosure;

[0054] FIG. 10 shows a cutaway section of a second part and second frame of the tool shown in FIG. 9, in accordance with the present disclosure; and

[0055] FIG. 11 shows a method of verifying thermal conductivity measurements of a heat flow probe, in accordance with the present disclosure.

[0056] Throughout the description and drawings, like reference numerals refer to like features.DETAILED DESCRIPTION

[0057] The following is a description of certain embodiments of the invention, given by way of example only and with reference to the drawings.

[0058] Various implementations of the disclosure are discussed in detail below. While specific implementations are discussed, it should be understood that this is done for illustration purposes only. A person skilled in the relevant art will recognize that other components and configurations may be used without parting from the spirit and scope of the disclosure. Thus, the following description and drawings are illustrative and are not to be construed as limiting. Numerous specific details are described to provide a thorough understanding of the disclosure. However, in certain instances, well-known or conventional details are not described in order to avoid obscuring the description. A reference to an implementation in the present disclosure can be a reference to the same implementation or any other implementation. Such references thus relate to at least one of the implementations herein.

[0059] The terms used in this specification generally have their ordinary meanings in the art, within the context of the disclosure, and in the specific context where each term is used. Alternative language and synonyms may be used for any one or more of the terms discussed herein, and no special significance should be placed upon whether or not a term is elaborated or discussed herein. In some cases, synonyms for certain terms are provided. A recital of one or more synonyms does not exclude the use of other synonyms. The use of examples anywhere in this specification including examples of any terms discussed herein is illustrative only and is not intended to further limit the scope and meaning of the disclosure or of any example term. Likewise, the disclosure is not limited to various implementations given in this specification. References to ranges of values or values “between” two values should be interpreted as encompassing the end points of those ranges unless otherwise specified.Description of heat flow cone penetrometer system

[0060] Referring to FIG. 1 , a side view of an example heat flow probe 1 in the form of a heat flow cone penetrometer system 1 is shown. The heat flow cone penetrometer system 1 shown in FIG. 1 is merely presented an example of a heat flow probe. It will be understood that wherever reference is made to a heat flow cone penetrometer system 1 , a more generally defined heat flow probe could be used. Such a heat flow probe does not necessarily have to be a heat flow cone penetrometer system 1 . While it is useful to measure cone resistance, pore pressure etc., simultaneously, a heat flow probe may also be a probe with a dummy tip having no other measurement capabilities beyond measuring temperature of target soil. In its most fundamental form, heat flow probe could be a probe with a heating element and a temperature measuring element, such as a thermometer.

[0061] The heat flow cone penetrometer system 1 , which is one example of a heat flow probe 1 , is arranged to measure subsurface thermal conductivity. The heat flow cone penetrometer system 1 comprises a cone penetrometer 2. The cone penetrometer may be a standard cone penetrometer commonly used in industry, or a penetrometer system having a dummy tip with no other measurement capabilities beyond temperature measurement. The cone penetrometer 2 extends between a tip 21 and a proximal end 22. The heat flow cone penetrometer system 1 further comprises a pushrod 3, which is arranged to translate a compressive force to the cone penetrometer 2 as it is being driven into a target soil. The pushrod 3 comprises a connection section 31 . The connection section 31 of the pushrod 3 is arranged to couple pushrod 3 to components of the heat flow cone penetrometer system 1 .

[0062] The heat flow cone penetrometer system 1 in the shown example comprises three heat flow modules 4, separated by intermediate sections 7. The heat flow modules 4 are provided between the proximal end 22 of the cone penetrometer 2 and the connection section 31 of the pushrod 3. Each of the heat flow modules 4 of the illustrated example comprises at least one heating element 41 and at least one temperature sensor 42 (both shown in FIG. 2).

[0063] Between the heat flow modules 4 in the shown example, a plurality of insulation rings 6 are provided. These insulation rings 6 are arranged to insulate the heat flow modules from one another, such that the heat produced by a first heat flow module 4 does not affect the temperature measurements of the temperature sensor 42 of a second heat flow module 4.

[0064] The heat flow modules 4 are axially stacked between the cone penetrometer 2 and the connection section 31 of the pushrod 3. The heat flow cone penetrometer system 1 may comprise more or fewer heat flow modules 4 than are depicted in FIG. 1 , as may be appropriate to achieve sufficient resolution of thermal dissipation in the target soil, and / or to increase the total range of measurement depth in one measurement cycle.

[0065] Now referring to FIG. 2, a cut-out view of the heat flow cone penetrometer system 1 according to an example is shown. For illustrative purposes, FIG. 2 shows only a single heat flow module 4 between the connection section 31 of the pushrod 3 and the proximal end 22 of the cone penetrometer 2. The heat flow modules 4 depicted in FIG. 1 may have the same features as the heat flow module 4 depicted in FIG. 2 and described here.

[0066] The heat flow module 4 comprises a dissipation sleeve 43 and an inner sleeve 44. The dissipation sleeve 43 is provided around the inner sleeve 44. The inner sleeve 44 comprises the heating element 41. In this case, the heating element 41 is a heating wire, which is spooled around the inner sleeve 44 through grooves 47 provided on an outer surface of the inner sleeve 44.

[0067] The heat flow module 4 further comprises a temperature sensor 42, which is contained in a slot on the outer surface of the inner sleeve 44. The heat generated by the heating element 41 in the form of a heating wire 41 provided in the grooves 47 on the outer surface of the inner sleeve is distributed through the inner sleeve 44 and the dissipation sleeve 43, which is provided around the inner sleeve 44. Once the measurement is started, the heat production through the heating wire 41 is halted, after which the temperature sensor 42 measures the decline in temperature as heat dissipates from the inner sleeve into the soil. In an alternative example, the measurement is performed during the heating of the heating wire 41 , such that the measurements by the temperature sensor 42 are taken simultaneously as the heat production by the heating wire 41 is started.

[0068] The heat flow module 4 further comprises an electronic control unit 5, which is provided in the middle of the heat flow module 4 such that it extends through the inner sleeve 44. The electronic control unit 5 is arranged to control the heat provided by the heating wire 41 and retrieve the measurement results from the temperature sensor 42 as the heat dissipation through the soil is measured.

[0069] An insulation ring 6 is provided at both ends of the heat flow module 4. The insulation ring 6 is used to help prevent heat loss into the rod above and below the inner sleeve 44, in an axial direction of the heat flow cone penetrometer system 1. In addition, the insulation ring 6 is arranged such that the inner sleeve 44 and the dissipation sleeve 43 are supported by the insulation ring 6. As a result, aninsulating air gap is defined between the inner sleeve 44 and an inner core of the heat flow cone penetrometer system 1 to prevent heat loss from the core of the heat flow cone penetrometer system 1 in a radial direction.

[0070] Now referring to FIG. 3, a three-dimensional view of the inner sleeve 44 of a heat flow module 4 in the heat flow cone penetrometer system 1 according to an example is shown. The inner sleeve 44 of the shown example comprises a set of two offset spiral grooves 47, which are arranged to receive a heating wire 41. The inner sleeve further comprises a plurality of slots 45, arranged to receive temperature sensors 42. These temperature sensors 42 are arranged to measure the change in temperature of the heat flow module 4 to determine the heat dissipation through a target soil.

[0071] The inner sleeve 44 of the shown example further comprises a hole 46, which extends through the inner sleeve 44 from an outer surface of the inner sleeve 44 to an inner surface of the inner sleeve 44. The hole 46 is arranged to receive the heating wire 41 , which may protrude through the hole 46 and extend through the inner sleeve 44 such that the heating wire 41 may be controlled and provided with power from within the inner sleeve 44 where the electronic control unit 5 is provided.

[0072] The inner sleeve 44 further comprises a temperature sensor cable hole 46, which is provided separately from the through-hole 46 for the heating wire 41 . The temperature sensor cable hole 46 is provided such that a cable extending from the temperature sensor 42 may extend through the inner sleeve 44 in a similar manner as the heating wire 41 , but without being provided in the same hole. The inner sleeves 44 of FIG. 2 and FIG. 4 may have the same features of the inner sleeve 44 depicted in FIG. 3 and described above.

[0073] Now referring to FIG. 4, a three-dimensional cross-sectional view of a section of the heat flow cone penetrometer system 1 , such as that depicted in FIG. 1 and FIG. 2, according to an example is shown. The section illustrates a heat flow module 4 of the heat flow cone penetrometer system 1 . The heat flow module 4 of the shown example comprises an inner sleeve 44, such as the inner sleeve depicted in FIG. 3, and a dissipation sleeve 43 provided around the inner sleeve 44. The inner sleeve 44 comprises grooves 47, in which a heating wire 41 is contained, such that the heating wire 41 turns around the inner sleeve 44. A plurality of temperature sensors 42 are provided in slots provided on an outer surface of the inner sleeve.

[0074] The heat flow cone penetrometer system 1 comprises an electronic control unit 5 provided in the heat flow module 4. In the shown example, a single electronic control unit 5 is provided in a single heat flow module 4. Similar heat flow modules 4 may also comprise an electronic control unit 5. Alternatively, one electronic control unit 5 may be utilized to control a plurality of heat flow modules 4. Two insulating rings 6 are provided on either side of the heat flow module 4, such that the insulation rings 6 support the dissipation sleeve 43 and the inner sleeve 44. The insulation rings 6 are provided such that they reduce the internal heat flow in an axial and radial direction of the heat flow cone penetrometer system 1 , improving the data acquisition quality.Description of tool for verifying thermal conductivity measurements of a heat flow probe

[0075] Referring to FIGS. 5 and 6, a tool 500 for verifying thermal conductivity measurements functionality of a heat flow probe, such as the heat flow probe 1 shown in FIGS. 1 to 4 and describedabove, is shown. The tool 500 will be described in relation to the heat flow probe 1 but it will be understood that the tool 500 could be configured for use with other types of heat flow probe.

[0076] The tool 500 is shown in an open position FIG. 5. and a closed in FIG. 6. The tool 500 has a first part 502 and a second part 504. The first part 502 has a first recess 506 (shown in FIG. 5) for receiving the heat flow probe 1 and the second part 504 has a second recess 508 (shown in FIG. 5) for receiving the heat flow probe 1 . When the tool 500 is in the closed position, the first recess 506 and the second recess 508 form a cavity 602 (shown in FIG. 6). In the depicted example, the first part 502 and the second part 504 are coupled to permit relative movement of the first part and the second part between the open position and the closed position. The first part and the second part are coupled via a pivotable coupling 510. The first part 502 is coupled to a first frame 512 and the second part 504 is coupled to a second frame 514.

[0077] At a very high-level, verification of the thermal conductivity measurements of the heat flow probe 1 can be carried out as followed. The heat flow probe 1 is inserted into one of the first recess 506 and the second recess 508 when the tool 500 is in the open position. The tool 500 is then closed so that the cavity 602 surrounds the heat flow probe 1 . The heat flow probe 1 is then actively heated to a desired temperature, at which point heating is stopped. The heat flow probe 1 then gives off heat to the surrounding first part 502 and second part 504 as the temperature of the heat flow probe 1 is higher than the temperature of the surrounding first part 502 and second part 504. The speed with which the temperature of the heat flow probe 1 reduces is indicative of the thermal conductivity of the first part 502 and the second part 504 surrounding the heat flow probe 1 . As the first part 502 and second part 504 and the second part are made of or include a reference material with a known value of thermal conductivity, the accuracy of the probe's thermal conductivity measurements can be verified.

[0078] Verifying the accuracy of the probe's thermal conductivity measurements is typically done by comparing the heat flow probe's measurement output when testing reference materials with known values of thermal conductivity. In the example of the tool 500, the first part 502 and the second part 504 could be made of or include such a reference material. The reference materials used should cover the range of expected thermal conductivity values measured in the field. For example, the range of expected thermal conductivity measurement values includes:0.4-1 .5 W / mK for peat (at the lower end of values found in the field);0.8-2.5 W / mK for clay; and1 .8-3.2 W / mK for sand (at the higher end of values found in the field).

[0079] Finding suitable reference materials can prove challenging, particularly for materials with higher thermal conductivity values. In the lower values of the range, water (mixed with agar to make it a solid jelly) is an example reference material at 0.598 W / mK that can be easy to use for probes of all dimensions. For the higher ranges between 1.8-3.2 W / mK, suitable reference materials include ceramics and glass or glasslike materials. However, the use of these materials can lead to certain challenges, particularly where larger diameter probes, for example with diameters of 44mm or larger, are to be tested.

[0080] In more detail, the depth of the reference material needs to be sufficient so that, during a thermal conductivity measurement verification test, the warm front created by the heat flow probe 1 has to stay within the reference material boundaries, to prevent measurement influence from surrounding environment. For example, the above described verification process can take 10 minutes. This means that the reference material has to be big enough for the warm front created by the heat flow probe 1 in this time period to stay within the reference material boundaries to keep the impact of surroundings negligible.

[0081] A suitable reference material is a ceramic and the first part 502 and the second part 504 could be made of or include a ceramic material or glass material having homogenous thermal conductivity properties. An example suitable ceramic is Zirconia (ZrC>2). Zirconia TZP (ZrC>2 TZP) could also be used. Zirconia TZP has a thermal conductivity value of 2.5 W / mK and so is suitable as a reference material in the higher end of values found in the field described above. Other materials of similar thermal conductivity values may be used, such as Macor or other ceramics of similar thermal conductivity values. Glass materials can also be used.

[0082] For ceramic materials, such as Zirconia TZP, an outer diameter of the reference material of 140 mm or greater could be required in order to perform a 10 minute verification process whilst minimising the impact of the surroundings. This would mean that the first part 502 and the second part 504 of the tool 500 would need to have an outer diameter of 140 mm or greater when the tool is in the closed position shown in FIG. 6. The length of the cavity 602 of the tool 500 would also need to sufficient to surround the heat flow module 4 or modules of the heat flow probe 1 being verified. In some examples, this could mean that the cavity 602 of the tool 500 needs to be 210 mm or greater in length.

[0083] Providing a ceramic reference material, such as Zirconia TZP, of this size can be challenging, the ceramic is sintered from a powder / adhesive mixture, and when the material thickness is increased, for example if it exceeds the 40 mm, issues can arise in that it may not be possible to fully cure the ceramic material. This would influence the material properties, mechanically and physically, meaning the structural integrity would be diminished and also thermal conductivity could be affected. It would also be difficult to predict the tolerances that the final product has.

[0084] Providing a glass reference material of this size would also be difficult to manufacture.

[0085] A solution to this problem provided in the tool 500 is for the first part 502 and the second part 504 to each be made of a plurality of ceramic or glass segments. The design of the tool 500 will now be described in greater detail with reference to FIGS. 5 to 10.

[0086] Starting with the first part 502 and the second part 504. As mentioned above the first part 502 has a first recess 506 (shown in FIG. 5) for receiving the heat flow probe 1 and the second part 504 has a second recess 508 (shown in FIG. 5) for receiving the heat flow probe 1. When the tool 500 is in the closed position, the first recess 506 and the second recess 508 form a cavity 602 (shown in FIG. 6). The cavity 602 may have a diameter designed to match the diameter of the heat flow module 4 or modules of the heat flow probe 1 . For example, where the diameter of the heat flow module 4 or modules of the heat flow probe 1 is 44 mm, the diameter of the cavity 602 would be 44 mm to ensure a close fit with the heat flow probe 1 when in the closed position. In some example implementations, the cavity 602 could have a diameter greater than or equal to the maximum diameter pf the heat flow module 4 ormodules of the heat flow probe 1 , which can be any value between 15 mm and 60 mm, for example 25.5 mm, 36 mm or 44 mm.

[0087] A reason for having a cavity 602 diameter designed to match the diameter of the heat flow module 4 or modules of the heat flow probe 1 is that any air or liquid present in between of the heat flow module 4 or modules and the reference material would form an insulative barrier, which disturbs the measurement taken by the probe during the verification process. Ensuring a close fit between the first part 502 and the second part 504 mitigates the risk and insulating air or liquid barrier arising during the verification process. Providing the first part 502 and the second part 504 as two parts that can be brought together also helps to facilitate a close fit as it makes it easer to place the heat flow probe 1 within the tool 500 when in the open position. This is particularly the case with larger diameter heat flow probes, such as those having a diameter of 44 mm or greater.

[0088] In some example implementations, a thermally conductive compound can be applied to the outer surface of the heat flow probe 1 , the first recess 506 and / or the second recess 508 to further ensure good thermal connection between the first part 502 and the second part 504 and the heat flow probe 1 . The thermally conductive compound can be chosen to match the thermal properties of the reference material used in the first part 502 and the second part 504 to minimise any impact on measurements taken during the verification process.

[0089] In some example implementations, the first part 502 and / or the second part 504 comprise a flow path for supplying a thermally conductive compound to the outer surface of the heat flow probe 1 , the first recess 506 and / or the second recess 508. For example, one or more channels or grooves could be provided on or in either or both of the first part 502 and the second part 504 so that a thermally conductive compound can be supplied to the cavity when the tool 500 is in the closed position.

[0090] As mentioned above, the first part 502 and the second part 504 can each be made of a plurality of segments. FIG. 7 depicts an example first part 502 comprising a plurality of segments 702. It will be understood that the second part 504 may have any of the features described in relation to the first part 502 as described herein and particularly as described in relation to FIG. 7. For example, the second part 504 may be made of the same segments 702 as the first part 502. Each of the segments 702 may have a thickness d in the longitudinal direction of the first part 502, as shown in FIG. 7. In some example implementations, the thickness d of each segment 702 is less than a predetermined amount to ensure the material of the segment can be fully cured during manufacture. For example, the thickness d could be 40 mm or less, where the segments are made of a ceramic such as Zirconia TZP.

[0091] In some example implementations, the thickness of each segment 702 is less than a predetermined amount, such as 40 mm or less, in any or every direction. In other words, any particle within the material of each segment 702 is no further than 20 mm from an edge of the segment 702.

[0092] In some example implementations, the segments 702 may be adhered to one another such that they form a single unit, as shown in FIG. 7. An adhesive may be used having thermal properties matching those of the material from which the segments 702 are made. For example, a Zirconia based adhesive may be used where the segments 702 are made from Zirconia such that the thermal conductivity of the adhesive matches or is close to the thermal conductivity of the segments 702. An example adhesive which could be used is Resbond 904.

[0093] As mentioned above, the second part 504 may comprise segments 702 as described in relation to the first part 502 and FIG. 7.

[0094] In the tool 500 depicted in FIGS 5, 6, 8 and 9, the first part 502 is coupled to a first frame 512 and the second part 504 is coupled to a second frame 514. The first frame 512 includes a handle 516 a handle for facilitating movement of the tool between the open and closed positions. The second frame 514 comprises a base 518 of the tool. The base 518 provides for stability of tool so that it can be opened and closed more easily. As can be seen in FIG. 8, the base 518 may include one or more anchoring points 802 for anchoring the base to a surface upon which the tool 500 is placed. This could, for example, comprise a screw for screwing into a surface, a magnet for magnetically securing the tool 500 to a surface or any suitable means for providing such an anchoring function. Other possible implementations of anchoring points 802 include Suction cups, rivets, nuts and bolts. In some example implementations, the tool 500 could be integrally formed with a surface, such as a countertop.

[0095] In the tool 500 depicted in FIGS 5, 6, 8 and 9, the first part 502 and the second part 504 are coupled to permit relative movement of the first part and the second part between the open position and the closed position. The first part and the second part are coupled via a pivotable coupling 510 in the form of two pivotable couplings 510 at either longitudinal end of the first part 502 and the second part 504. In some example implementations, a single pivotable coupling 510 could be provided. In the example tool 500 shown in FIGS 5, 6, 8 and 9, the pivotable couplings 510 are provided between the first frame 512 and the second frame 514. In some example implementations, the pivotable coupling or couplings 510 could be provided directly between the first part 502 and the second part 504. In this example, the first frame 512 and the second frame 514 may not be provided as part of the tool 500.

[0096] In the tool 500 depicted in FIGS 5, 6, 8 and 9, at least one damper 520 is provided. The damper 520 is configured to dampen relative movement of the first part 502 and the second part 504 when moving from the open position to the closed position. A damper 520 may be provided between the first frame 512 and the second frame 514. Two or dampers 520 may be provided and a damper 520 may be provided at either longitudinal end of the first part 502 and the second part 504, as shown in FIGS 5, 6,8 and 9.

[0097] As shown in a cutaway section of the first part 502 and first frame 512 in FIG. 9, the first part 502 is coupled to the first frame 512 via a first coupling 902 in the form of a first pin 902 running through the segments 702 of the first part 502. The first pin 902 engages corresponding orifices 906 in the first frame 512 at either end of the first pin 902 (only one of these is shown in FIG 9) such that movement of the first pin 902 relative to the first frame 512 is permitted.

[0098] As shown in a cutaway section of the second part 504 and second frame 514 in FIG. 9, The second part 504 is coupled to the second frame 514 via a second coupling 904 in the form of a second pin 904 running through the segments 702 of the second part 504. The second pin 904 engages corresponding orifices 906 in the second frame 514 at either end of the second pin 904 (only one of these is shown in FIG 9) such that movement of the second pin 904 relative to second frame 514 is permitted.

[0099] FIG. 10 shows the cutaway section of the second part 504 and second frame 514 shown in FIG.9 in greater detail. As can be seen, the orifice 908 is provided in the second frame 514. In the exampleshown in FIG 10, an insert 1002 is provided within the orifice 908 in the form of a bushing 1002. As can be seen in FIG. 10, the second pin 904 is located with the insert 1002 and a headspace 1004 provided to permit movement of the second pin 904 and segments 702 through which the second pin 904 is inserted in the longitudinal direction of the second part 504. The insert 1002 itself may be made of a resilient material to provide a damping function and / or to facilitate movement of the second pin 904 and segments 702 in a direction orthogonal to the longitudinal direction of the second part 504. This coupling arrangement can facilitate a closer fit between the segments 702 of the second part 504 and a heat flow probe 1 when in the closed position.

[0100] It will be appreciated that the above described features of the orifices 908 provided in the second frame 514 apply equally to the orifices 906 in the first frame 512, which may also include an insert and any or all of the other features of the orifices 908 provided in the second frame 514.

[0101] In some example implementations, the first part 502 could be coupled to the first frame 512 in other ways and the second part 504 could be coupled to the second frame 514. For example, a flexible connection, such as a rubber strip, with clamps at either end could be used to clamp the first part 502 to the first frame 512 and the second part 504 to the second frame 514. An adhesive could also be used.

[0102] In some example implementations, the first part 502 and the second part 504 are provided in isolation without any other features of the tool 500. In such an implementation, the first part 502 may simply be placed on top of the second part 504 by the user after the heat flow probe 1 is inserted into one of the first recess 506 and the second recess 508 to conduct the verification process.

[0103] In some example implementations, a system is provided having a heat flow probe 1 of the type described above and a tool 500 of the type described above.

[0104] FIG. 11 shows a method of verifying thermal conductivity measurements of a heat flow probe 1 , such as the heat flow probe 1 described above, using the tool 500.

[0105] At step 1102, the heat flow probe 1 is inserted into the tool 500 when the tool 500 is in the open position.

[0106] At step 1104, the tool 500 is moved to the closed position in which at least a portion of the heat flow probe 1 is enclosed by the first part 502 and the second part 504.

[0107] At step 1106, a thermal conductivity measurement is obtained from the heat flow probe.

[0108] At step 1108, the thermal conductivity measurement is compared with a known value of the thermal conductivity of the first part 502 and / or the second part 504.

[0109] The steps of the method described above may be performed in any suitable order.

[0110] It is to be understood that the above description is intended to be illustrative, and not restrictive. Many other implementations will be apparent to those of skill in the art upon reading and understanding the above description. Although the present disclosure has been described with reference to specific example implementations, it will be recognized that the disclosure is not limited to the implementations described but can be practiced with modification and alteration within the spirit and scope of the appended claims. Accordingly, the specification and drawings are to be regarded in an illustrative sense rather than a restrictive sense. The scope of the disclosure should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

[0111] While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist, only some of which have been mentioned above. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the disclosure in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the exemplary embodiment or exemplary embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope of the disclosure as set forth in the appended claims and the legal equivalents thereof.

Claims

CLAIMS1 . A tool for verifying thermal conductivity measurements of a heat flow probe, the tool comprising: a first part comprising a first recess for receiving the heat flow probe, wherein the first part comprises a first ceramic or glass material; a second part comprising a second recess for receiving the heat flow probe, wherein the second part comprises a second ceramic or glass material, wherein the first part and the second part are movable relative to one another between an open position in which the heat flow probe can be inserted into one or more of the first recess and the second recess and a closed position in which the first recess and the second recess form a cavity for enclosing at least a portion of the heat flow probe.

2. The tool of claim 1 , wherein the first part and the second part are coupled to permit the relative movement of the first part and the second part between the open position and the closed position3. The tool of claim 1 or claim 2, wherein the first part comprises a first plurality of ceramic or glass segments4. The tool of any preceding claim, further comprising a first frame, wherein the first part is coupled to the first frame via a first coupling.

5. The tool of claim 4, wherein the first coupling is configured to permit movement of the first part relative to the first frame.

6. The tool of claim 4 or claim 5, wherein the first coupling comprises a first pin running through the first part.

7. The tool of claim 6, wherein the first pin engages corresponding orifices in the first frame such that movement of the first pin relative to the first frame is permitted.

8. The tool of any of claims 4 to 7, wherein the first frame comprises a handle for facilitating movement of the tool between the open and closed positions.

9. The tool of any preceding claim, wherein the first part and / or the second part comprises a flow path for supplying a thermally conductive compound to an outer surface of the heat flow probe when the tool is in the closed position.

10. The tool of any preceding claim, wherein the second part comprises a second plurality of ceramic or glass segments.11 . The tool of any preceding claim, further comprising a second frame, wherein the second part is coupled to the second frame via a second coupling.

12. The tool of any preceding claim, wherein the first ceramic material and / or the second ceramic material comprise Zirconia TZP.

13. A method of verifying thermal conductivity measurements of a heat flow probe, the method comprising: inserting the heat flow probe into the tool of any preceding claim when the tool is in the open position; moving the tool to the closed position in which at least a portion of the heat flow probe is enclosed by the first part and the second part; obtaining a thermal conductivity measurement from the heat flow probe; and comparing the thermal conductivity measurement with a known value of the thermal conductivity of the first part and / or the second part.

14. A component for use in a tool for verifying thermal conductivity measurements of a heat flow probe, the component having the features of the first part or the second part of any of claims 1 to 12.

15. A system comprising: a heat flow probe; and the tool of any of claims 1 to 12.

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