Steerable tip and mounting configuration for fiber optic temperature sensing probes - Patents.com

Abstract

A fiber optic temperature sensing probe is described. The probe includes a probe shaft having a first portion with a first protrusion and a cavity for locating a fiber optic cable therein. The probe includes a ferrule with a second protrusion that cooperates with the first protrusion to prevent the ferrule and the probe shaft from disengaging from an assembled configuration. The probe includes a biasing member connected to the ferrule and the first portion to facilitate displacement between the ferrule and the first portion. The probe includes a sensing element disposed at a distal end of the ferrule and proximate to a surface to be measured, the sensing element configured to interact with light received from the fiber optic cable to measure a temperature of the surface to be measured.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63 / 268,345, filed February 22, 2022, the contents of which are incorporated by reference in their entirety herein.

[0002] Technical Field The following relates generally to sensing probes, such as fiber optic temperature sensing probes used to measure the temperature of a surface, and more particularly to adjustable sensing probes. [Background technology]

[0003] background Fiber optic temperature sensors, such as temperature probes, typically contain an optical fiber capable of transmitting light to a sensing material (e.g., a phosphor). When light shines on the phosphor, it luminesces. By observing the change in certain properties of the emitted light, the temperature of the phosphor can be determined. Temperature differences between the phosphor and the surface being measured (i.e., the target surface) can make it difficult to calibrate the sensor to obtain accurate measurements.

[0004] Generally, a fiber optic temperature probe includes a base and a single tube extending from the base with an optical fiber located therein. A sensing tip containing a sensing material is attached to the end of the tube so as to contact the target surface. The tube is intended to provide the probe with mechanical strength and durability to environmental conditions while ideally reducing heat loss from the tip to maintain the sensing material at a temperature as close as possible to that of the target surface. In addition to possessing the above qualities, the tube must be resistant to high temperatures and corrosion to facilitate processes such as dry etching, where the material is etched with corrosive chemicals at high temperatures, making material selection difficult.

[0005] Sensing tips are typically tightly aligned to their target surfaces, and because of this there is often a small angle that prevents flush contact between the surfaces, especially when smooth, hard surfaces are being measured. Poor contact between the target surface and the sensor tip can slow down temperature measurements by reducing the rate of heat transfer between the target surface and the tip. Poor contact can also introduce additional thermal resistance, causing deviations between the measured temperature and the actual temperature.

[0006] Additionally, the temperature probe sensing tip may be rigidly secured to the tube using bonding or mechanical structures. These configurations are known to impose undesirable and potentially problematic stresses on the components both during installation and use of the probe. Additionally, in some applications, the area in which to install the probe may be relatively small, creating difficulties during installation. Summary of the Invention

[0007] overview In one aspect, a fiber optic temperature sensing probe is described. The probe includes a probe shaft having a first portion with a first protrusion and a cavity for locating a fiber optic cable therein. The probe includes a ferrule having a second protrusion that cooperates with the first protrusion to prevent the ferrule and the probe shaft from disengaging from an assembled configuration. The probe includes a biasing member connected to the ferrule and the first portion to facilitate displacement between the ferrule and the first portion. The probe includes a sensing element disposed at a distal end of the ferrule and proximate a surface to be measured, the sensing element configured to interact with light received from the fiber optic cable to measure a temperature of the surface to be measured.

[0008] In example embodiments, the sensing element snaps into the opening in the ferrule or includes threads complementary to threads adjacent the opening in the ferrule, and in example embodiments, the opening has a chamfered lip to facilitate a snap-in fit of the sensing element.

[0009] In an example embodiment, the second protrusion has a chamfered lip to create a snap-in fit with the first protrusion.

[0010] In an example embodiment, the ferrule includes a first chamber extending from the sensing element into a wider second chamber to define a shoulder that limits movement of the first protrusion toward the sensing element. In an example embodiment, the shortest distance between the sensing element and the probe shaft in the optical axis is defined by the shoulder.

[0011] In an example embodiment, the second projection has an inner chamfer for interacting with the rearward shoulder of the first portion to prevent the probe shaft and the ferrule from coming apart.

[0012] In example embodiments, the ferrule or the sensing element is coupled to the surface to be measured.

[0013] In an example embodiment, the base of the probe shaft engages a seal to form a vacuum seal between the probe shaft and the surface being measured, and in an example embodiment, the base of the probe shaft is separable from the first portion.

[0014] In example embodiments, the ferrule includes at least a first ferrule part and a second ferrule part different from the first ferrule part, and in example embodiments, the first ferrule part is rotatable relative to the second ferrule part or is rotatable relative to the probe shaft.

[0015] In an example embodiment, the probe further comprises a seal that interacts with a wall and the probe shaft to create a vacuum seal.

[0016] In example embodiments, the sensing element includes one or more of diamond, aluminum, copper, gold, nickel or nickel alloy, aluminum nitride, and silicon carbide.

[0017] In an example embodiment, the contact area between the sensing element and the ferrule is 2 mm 2 Less than or equal to 1 mm 2 Less than or equal to 0.5 mm 2 Less than or equal to 0.25 mm 2 is less than

[0018] In example embodiments, the sensing element has a thermal conductivity greater than 20 W / m-1K, or greater than 150 Wm-1 / K, or greater than 225 Wm-1 / K, or greater than 300 Wm-1 / K.

[0019] In another aspect, a fiber optic temperature sensing system is disclosed. The system includes a probe body. The probe body includes a base portion, a body extending from the base portion and terminating in a head portion, a passageway through the base portion and the probe body, and a fiber optic cable within the passageway. The system includes at least one ferrule having a first opening at a first end that provides a snap-in or threaded fit with the head portion. The system includes a biasing member disposed to apply a force to the at least one ferrule toward a surface to be measured, and a sensing element located at a second end of the at least one ferrule opposite the first end. The sensing element includes a sensing material for interacting with light from the fiber optic cable located within the passageway.

[0020] In an example embodiment, the sensing material is coupled to the surface to be measured.

[0021] In another aspect, a method of assembling a fiber optic temperature sensing probe is disclosed. The method includes providing a first portion and a second portion of a probe shaft, the first portion and the second portion of the probe shaft including a passage configured to receive a fiber optic cable. The method includes providing a first fiber optic cable and a second fiber optic cable, and inserting the first fiber optic cable into the first portion of the probe shaft. The method includes inserting the second fiber optic cable into the second portion of the probe shaft and providing a block. The method includes providing a cap, connecting the first portion of the probe shaft to the block, and connecting the second portion of the probe shaft into the cap. The method includes assembling the block into the cap and optically aligning the fiber optic cables of the first portion of the probe shaft and the second portion of the probe shaft, respectively.

[0022] In an example embodiment, connecting the first portion of the probe shaft to the block includes sealing the first portion of the probe shaft to the block with a seal. In an example embodiment, the first portion of the probe shaft includes a ferrule having at least a first ferrule part and a second ferrule part different from the first ferrule part, the first ferrule part configured to rotate relative to the second ferrule part or to rotate relative to the probe shaft. In an example embodiment, the first portion of the probe shaft includes a ferrule having at least a first ferrule part and a second ferrule part different from the first ferrule part, the first ferrule part configured to rotate relative to the first portion of the probe shaft. [Brief description of the drawings]

[0023] BRIEF DESCRIPTION OF THE DRAWINGS Embodiments will now be described with reference to the accompanying drawings.

[0024] [Figure 1A] FIG. 1A is a cross-sectional view of a fiber optic temperature probe supported in a mounting block adjacent to an object to be measured.

[0025] [Figure 1B] FIG. 1B is a cross-sectional view of a fiber optic temperature probe that consists of two separable sections.

[0026] [Figure 1C] FIG. 1C is a cross-sectional view of an example fiber optic temperature probe supported and sealed within a mounting block.

[0027] [Figure 1D] FIG. 1D is a cross-sectional view of another example of a fiber optic temperature probe supported and sealed within a mounting block.

[0028] [Diagram 2] FIG. 2 is a perspective view of the fiber optic temperature probe of FIG. 1A.

[0029] [Diagram 3] FIG. 3 is a cross-sectional view of a ferrule coupled to the distal end of the fiber optic temperature probe of FIG. 1A.

[0030] [Figure 4-5] 4 and 5 are side views illustrating axial movement of an example temperature probe shaft relative to a ferrule.

[0031] [Figure 6-7] 6 and 7 are perspective views illustrating axial movement of an example temperature probe shaft relative to a ferrule.

[0032] [Figure 8]FIG. 8 shows an example configuration of a temperature probe having an integrated ferrule and sensing element.

[0033] [Figure 9] FIG. 9 shows a configuration of a temperature probe that is directly coupled to the object being measured.

[0034] [Figure 10] FIG. 10 illustrates an example temperature probe configuration in which axial movement of the probe shaft relative to the ferrule is restricted.

[0035] [Figure 11A] FIG. 11A is a cross-sectional view of an example fiber optic temperature probe and a two-part ferrule.

[0036] [Figure 11B] FIG. 11B is another cross-sectional view of the example fiber optic temperature probe of FIG. 11A in an adjusted configuration. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] Detailed Description Turning now to the drawings, FIG. 1A illustrates a sensing environment, in this example environment 10. In this environment 10, a fiber optic temperature probe 12A is used to measure the temperature of an object 14 through contact with a surface 15 of the object 14. The object 14 may be any component or structure that provides a contact surface where a temperature measurement is desired, such as, for example, an electrostatic chuck in a semiconductor chamber. The temperature probe 12A is connected to, supported by, adjacent to, or in close proximity to the object 14 being measured by a support block 16. The support block 16 includes a passageway 17 that is sized and configured such that the probe 12A may be inserted and positioned therein. The probe 12A is positioned within the passageway 17 and may advance toward and engage an exposed surface 15 of the object 14 being measured such that the probe 12A may contact the object 14 being measured to enable temperature sensing as described in more detail below.

[0038] In the illustrated example, the temperature probe 12A is fitted into the cap block 18 by an O-ring 20. Other sealing mechanisms are contemplated. A transition block 22 is secured to the cap block 18, and together the cap block 18 and the transition block 22 define a passage 24 through which a cable 26 (e.g., a fiber optic cable, hereafter referred to as optical cable 26 for ease of reference) can pass. It will be appreciated that the depiction between the cap block 18 and the transition block 22, respectively, in FIG. 1A is for illustrative purposes, and other configurations are contemplated, such as the transition block 22 extending as a single piece to the block 16. FIG. 1A shows a connector 30 for connecting the optical cable 26 to a unit, also referred to as a transducer or sensing unit, that provides excitation light and analyzes the emitted light to provide temperature information. In the illustrated example, the optical cable 26 includes a relatively sharp bend (i.e., substantially 90 degrees) into the cap block 18 and is protected by a jacket 28. 1A shows the transition block 22 and the cap block 18 as separate components, in other embodiments, the transition block 22 and the cap block 18 may be a single component. In example embodiments, different blocks are connected to different portions of the probe 12A. For example, the cap block 18 may be connected to the second portion 13B and the block 16 may be connected to the first portion 13A. In various example embodiments, the temperature probe 12A may be installed in the cap block 18 and the transition block 22 prior to installation of the support block 16. In other embodiments, the installation process may be performed in a different order and / or with fewer or additional components.

[0039] It can be appreciated that in environments where the optical cable 26 has sharp bends, a bundle of thin optical fibers can be used to accommodate the bends. In various example embodiments, at least a portion of the optical cable 26 can include one or more plastic fibers, one or more glass fibers, or one or more silica fibers. For example, the individual fibers in such a bundle can slide relative to one another to more easily and relieve stress and accommodate the bends. In various example embodiments, the radius of curvature of the flexible portion of the optical cable 26 can be less than about 50 mm, or less than about 25 mm, or less than about 15 mm, or less than about 5 mm. It can also be appreciated that the sensing environment 10 shown in FIG. 1A illustrates one application of the temperature probe 12A, and the principles described herein are equally applicable to other environments and applications.

[0040] FIG. 1B illustrates another exemplary temperature probe, incrementally designated 12B. The second portion 13D of the temperature probe 12B is similar to the second portion 13B of the probe 12A described with reference to FIG. 1A. The temperature probe 12B includes a first portion 13C that is different from the first portion 13A (FIG. 1A) of the probe 12A. In the following, the first portions 13A and 13C and the second portions 13B and 13D are referred to instead as upper and lower portions for ease of reference. The upper portion 13C is configured to be attached to or mechanically coupled to the support block 16. Similarly, in the illustrated embodiment, the lower portion 13D may be configured to be attached to or mechanically coupled to the cap block 18 and / or the transition block 22, respectively.

[0041] The upper and lower portions 13C, 13D may be separable and resealable (e.g., via mechanical joints such as complementary fasteners). The optical cable 26 may in this regard be separable within the upper and lower cable portions 26A, 26B. For example, the upper and lower portions 13C, 13D may include mating mechanical features such as complementary threads that allow the portions to be engaged, assembled, and separated. In other embodiments, the upper and lower portions 13C, 13D may be configured to sit within the cap block 16 and transition block 18, respectively, such that they are not mechanically interlocked, but the optical axes of the cable portions 26A, 26B are collinear.

[0042] As mentioned above, one or more alignment features can be used to assemble the upper and lower portions 13C, 13D. The alignment features can enable (resealing) and separation of the portions 13C and 13D, and / or can simplify optical alignment of the ends of the cable portions 26A and 26B. The alignment features can be present in one or both of the portions 13C and 13D. With regard to alignment, in various example embodiments, the optical collinearity between the cable portions 26A and 26B (the distance between the respective optical axes of the cable portions 26A, 26B, where the optical axis is defined by the direction of light exiting or entering the ends of the optical fiber portions) can be less than 0.5 mm, or less than 0.25 mm, or less than 0.1 mm, or less than 0.05 mm. In various example embodiments, the alignment features are one or more fasteners 29 that interact with portions 13C and / or 13D to at least partially secure probe 12B to one of support block 16, cap block 18, or transition block 22, respectively. Examples of fasteners 29 include adhesives, mechanical fasteners, etc.

[0043] Also, portions 13C and 13D may be sealed to support block 16 or cap block 18 and transition block 22. For example, an O-ring may be used to form a seal between upper portion 13C and support block 16. In example embodiments, alignment features are at least partially responsible for sealing the portions to one of the blocks. In various embodiments, such a seal may be a vacuum seal, for example, to prevent leakage from within passageway 17 to the outside environment.

[0044] For clarity, in an assembled configuration, portions 13C and 13D allow light to pass bidirectionally between cable portions 26A and 26B. The assembled configuration may include cable portions 26A and 26B that contact one another and are separated by gap 27 that allows cable portions 26A and 26B to pass light bidirectionally between them.

[0045] In example embodiments, probe 12B can be assembled in a variety of different ways. For example, upper portion 13C can be attached to support block 16, which allows for placement of lower portion 13D within cap block 18 and transition block 22, and separate placement of portion 13C within support block 16, such that support block 16 and cap block 18 and transition block 22 can be physically separated and joined without requiring additional support of either portions 13C and 13D while still providing optical alignment of cable portions 26A, 26B.

[0046] The temperature probes disclosed herein may be configured for subatmospheric ambient pressures. Figures 1C and 1D show exemplary temperature probes 12C and 12D, respectively, for use at subatmospheric ambient pressures. It is understood that other systems having similar functionality are contemplated. For example, temperature probe 12C (Figure 1C) may be configured to operate at pressures of less than about 1E-3 torr, or less than about 1E-4 torr, or less than about 1E-6 torr.

[0047] The temperature probe 12C includes a seal 31 between the optical cable 26 and the lower portion 13B. For example, the seal 31 can be a metal seal (e.g., a metal seal that closes both ends of a cavity), an adhesive (e.g., an epoxy or ceramic adhesive), a radial seal, or other seal such as an O-ring on the end of the gap between the optical cable 26 and the lower portion 13B. In at least some example embodiments, the assembled configuration of the probe 12C includes a seal (not shown) between the lower portion 13B and the cap block 18 similar to the seal 31 between the optical cable 26 and the lower portion 13B. In example embodiments, the seal 31 includes or creates a vacuum sealed cavity. Various ways of achieving the seal 31 are contemplated. It is understood that the term seal does not require a perfect seal. For example, the seal 31 can have a leak rate of less than about 1E-8 torr-l / sec, or less than about 1E-9 torr-l / sec, or less than about 1E-10 torr-l / sec.

[0048] Probes according to the disclosed embodiments may be sealed in cooperation with various features of blocks 16, 18, 22. For example, Figure 1D shows a temperature probe 12D that is at least partially sealed between surface 15 and blocks 16, 18, 22 by potting compound 25 that surrounds optical cable 26 and is located within passage 24 (Figure 1C).

[0049] It is understood that the probes 12A, 12B, 12C, 12D shown in Figures 1A, 1B, 1C, 1D may be configured to operate without seals, with combinations of seals shown therein, with various combinations of seals, or with seals different from those shown. For example, although an O-ring 20 is shown in Figures 1A and 1B as providing a face seal, in other embodiments seals having different dimensions, such as radial seals or other types of seals, may be used.

[0050] It is contemplated that the probe and cable may be sized differently. For example, with reference to FIG. 1A, in various embodiments, the upper portion 13A may have a diameter of less than about 40 mm, or less than about 25 mm, or less than about 10 mm. In various embodiments, the optical cable 26 may have a diameter of less than about 5 mm, or less than about 3 mm, or less than about 1 mm. In various embodiments, the length of the temperature probe 12A located within the support block 16 may be less than about 400 mm, less than about 100 mm, or less than about 50 mm.

[0051] FIG. 2 shows a perspective view of the temperature probe 12A. The probe 12A includes a shaft 40 having an upper portion 13A and a lower portion 13B. The shaft 40 includes a connector portion 48 (alternatively referred to as a base portion 48) on the lower portion 13B that supports an O-ring 20 to connect the probe 12A to, for example, the cap block 18 shown in FIGS. 1A-1D. However, the connector portion 48 may be suitably adapted to mate with or fit into other structures, and may or may not require an O-ring 20 to do so. The connector portion 48 is also connected to a jacket 28 through which the fiber optic cable 26 enters the probe shaft 40. The upper portion 13A includes a stepped main body 47 extending from the connector portion 48 and includes an intermediate shoulder 45. The shoulder 45 provides a surface against which a biasing element, such as a spring 46, may be engaged.

[0052] A ferrule 42 or other tubular component is assembled with, attached to, or connected to the upper portion 13A (e.g., at the distal end of the shaft 40). The ferrule 42 may be formed from a variety of materials depending on the application. For example, the ferrule 42 may include high temperature plastics, ferrous or non-ferrous metals, or ceramics, particularly for high temperature applications. The ferrule 42 provides a counter surface with which a spring 46 can engage to bias (or displace) the ferrule 42 away from the base portion 48 to press the sensing element 44 against a surface, such as the surface 15 of the object 14 being measured as shown in FIGS. 1A-1D. The sensing element 44 may also be referred to as a "button" or a "tip."

[0053] Referring to FIG. 3, a cross-sectional view of the ferrule 42 and interacting components is shown. Starting at the distal end of the ferrule 42, it can be seen that a chamfered opening 56 is provided to allow the sensing element 44 to snap-in within the opening 56. The sensing element 44 includes a peripheral lip 54 that is also chamfered at its front end to facilitate insertion of the sensing element 44 into the opening 56 during installation. The lip 54 provides an orthogonal surface opposite the chamfered surface to hold the sensing element 44 in place once the sensing element 44 snaps into the ferrule 42. As best seen in FIG. 3, the sensing element 44 is an open-ended structure that provides a cavity 52 that allows light to pass from the optical fiber of the optical cable 26 to a sensing material 50 of the sensing element 44, which is affixed to an innermost surface 49 of the cavity 52 (alternatively referred to as the inner surface 49 of the sensing element 44). For clarity, when described herein, the sensing material 50 and the sensing element 44 may be collectively referred to as the sensing element 44 for simplicity, and the interior surface 49 will be understood to include the sensing material 50. The sensing material 50 is excited by light transmitted through the optical fiber. The sensing material 50 is advantageously a phosphorescent material, such as a phosphor, although other materials will be known to those skilled in the art.

[0054] The ferrule 42 may be a tubular member or may include a cavity or passage therethrough. In this example, the distal opening 56 leads into a first chamber 58. The first chamber 58 transitions to a wider second chamber 60 and defines a shoulder 62. The second chamber 60 allows a head portion 66 of the probe shaft 40 to slide axially within the ferrule 42.

[0055] During assembly, the head portion 66 of the probe shaft 40 is inserted into the second chamber 60 by inserting an outer facing projection 73 (hereinafter referred to in the singular for ease of reference) of the head portion 66 into an opening in the ferrule 42. The opening is defined at least in part by an inner facing projection 64A (hereinafter referred to in the singular for ease of reference) which opposes projection 73 to allow for a snap-in fit. It is understood that the term projection is at least in part defined by a radial direction relative to the optical path of the optical cable 26.

[0056] Protrusion 64A may include a chamfered inner surface 64B to facilitate insertion of protrusion 73 into chamber 60. A chamfered extension 68 projects from head 66 and is relatively narrower than protrusion 73 to facilitate alignment of probe shaft 40 with the opening defined by chamfered surface 64B during assembly.

[0057] As mentioned above, the head portion 66 may include a protrusion 73 to prevent the probe shaft 40 from disengaging or coming apart from the ferrule 42. The protrusion 73 may include a polygonal outer surface to provide a snap-in feature to facilitate assembly of the sensing probe 12. For example, as shown in FIG. 3, this outer surface of the protrusion 73 may provide a chamfered forward shoulder 71 to facilitate insertion of the head portion 66 into the opening of the ferrule 42. The outer surface of the protrusion 73 may also include a rearward shoulder 72 that resists the chamfered inner surface 74 of the protrusion 64A and thereby inhibits (but does not prevent) the probe shaft 40 from disengaging from the ferrule 42. In this manner, the ferrule 42 may be biased under the influence of the spring 46 (or other biasing member) away from the base portion 48 of the probe shaft 40 while maintaining the ferrule 42 in an assembled configuration with the probe shaft 40. Also, the chamfered inner surface 74 may allow the probe shaft 40 to separate from the ferrule 42 during installation, assembly, testing, etc. For example, if the sensing material 50 needs to be changed, the ferrule 42 may be removed from the probe shaft 40 and then reinstalled after the sensing material 50 is replaced. The cross-sectional view in Figure 3 also illustrates the passage of the optical cable 26 through a channel or perforation in the probe shaft 40. As mentioned above, the optical cable 26 may be embodied by a bundle of fibers, and in this example, the optical cable 26 may be housed with a PTFE sleeve 76 or other coating or sheath.

[0058] The ferrule 42 and probe shaft 40 assembly facilitates the passage of light towards the sensing element 44. In various example embodiments, the sensing element 44 may include or be constructed from a material having a relatively high thermal conductivity, such as diamond, aluminum, copper, gold, nickel or nickel alloys, aluminum nitride, silicon carbide, etc. In various example embodiments, the sensing element 44 may have a thermal conductivity of greater than about 20 W / m-1K (e.g., using alumina), greater than about 150 Wm-1 / K, or greater than about 225 Wm-1 / K, or greater than about 300 Wm-1 / K.

[0059] In various example embodiments, the ferrule 42 and the sensing element 44 may be configured to reduce thermal conductivity between the sensing element 44 and the ferrule 42. For example, the contact area between the sensing element 44 and the ferrule 42 may be reduced, or a thermal insulator (e.g., a low thermal conductive coating) may be applied to the surface of one or both materials to increase the thermal resistance between the sensing element 44 and the ferrule 42. In various example embodiments, the contact area between the sensing element 44 and the ferrule 42 may be reduced to approximately 2 mm. 2 Less than or about 11 mm 2 Less than or about 0.5 mm 2 Less than or about 0.25 mm 2 It may be less than.

[0060] In various example embodiments, the ferrule 42 may include or be constructed from materials such as glass, aluminum oxide, aluminum, copper, aluminum nitride, silicon carbide, zirconia, polyetheretherketone (PEEK), polyimide, polyamideimide (PAI), polybenzimidazole (PBI), Ultem, and the like.

[0061] 4 and 5 further illustrate the movement of the head portion 66 within the second chamber 60. FIG. 4 illustrates, with arrows, snap-in features that i) allow the installation of the sensing element 44 on the ferrule 42 and ii) allow the probe shaft 40 to be inserted into the ferrule 42 or snapped onto the head portion 66 of the probe shaft 40 depending on the assembly or installation used. The snap-in feature of the ferrule 42 thus provides a quick connection system for the sensing probe 12 that significantly facilitates assembly, especially in applications where space is limited. Additionally, the modularity of the disclosed probes facilitates the selection of different sensing elements 44, sensing materials 50, upper portions 13A and lower portions 13B to respond to different environmental and operating conditions. For example, one portion of the probe may be selected for its ability to withstand corrosion resulting from use in etching applications and other portions for their mechanical strength, while the sensing material may be selected based on desired accuracy, etc.

[0062] 4 also shows further detail of the exterior surface of the head portion 66. In this example, the polygonal exterior surface defines a series of circumferentially spaced ridges 80 that provide relief for the snap-in action when the head portion 66 is inserted into the ferrule 42 or when the ferrule 42 is snapped onto the head portion 66. This can reduce stress on the ferrule 42 during installation.

[0063] As seen in FIG. 5, when the ferrule 42 presses the probe shaft 40 further down (or when the probe shaft 40 is positioned to its maximum extent within the ferrule 42), a shoulder 62 located at the interface between the first chamber 58 and the second chamber 60 prevents the extension 68 from contacting the sensing element 44, e.g., preventing the probe shaft 40 from disengaging from the ferrule 42 or from dislodging from the sensing element 44. For clarity, the ferrule 42, together with the shoulder 62, may be dimensioned such that a minimum distance 67 (i.e., the depth of the gap 82) is maintained between the end of the shaft 40 and the end of the sensing element 44. That is, the gap 82 between the sensing element 44 and the extension 68 is achieved by the shoulder 62. It may be appreciated that the gap 82 and the depth of the cavity 52 (shown in FIG. 3) within the sensing element 44 may vary based on the desired distance between the sensing material 50 and the end of the optical cable 26. Similarly, the length of extension 68 and the depth of first chamber 58 may be varied to affect or contribute to this desired distance. In at least some example embodiments, the depth of gap 82 is less than about 20 mm, or less than about 10 mm, or less than about 5 mm, or less than about 1 mm.

[0064] Figures 6 and 7 provide further views of the sliding movement shown in Figures 4 and 5. Transparency applied to the ferrule 42 in these views reveals the biasing effect of the ferrule 42 against the probe shaft 40. The spring 46 or other biasing element used can be selected to calibrate the desired contact force between the sensing element 44 and the object 14 being measured.

[0065] As mentioned above, the configuration of the sensing probe 12 as shown in Figs. 1-7, such as that shown in Fig. 1, is only one preferred configuration for certain applications. Various other configurations are contemplated for different components, production volumes, available manufacturing techniques, etc. For example, as shown in Fig. 8, a single component can be used to provide an integrated ferrule 142 and sensing element 144. In this example, the sensing material 50 can be located in the same position as in the embodiment described above, and the shoulder 62 and second chamber 60 can be similar to those shown in Fig. 3. As a result of the integrated configuration of the ferrule 142 and sensing element 144, the modified first chamber 258 does not include the lip 54 and opening 56 of Fig. 3, potentially simplifying manufacturing. The integrated configuration of the sensing element 144 can be particularly suitable for mass production where injection molding methods are economical. In contrast, for low volume production where adaptability is desirable, the snap-in sensing element of Fig. 3 may be preferred. It will be appreciated that the probe shown in Figure 8 incorporates the snap-in feature provided by head portion 66 and projection 64 of probe shaft 40 of Figure 2 and it is not necessary to repeat the details thereof.

[0066] Another example configuration is shown in Figure 9, in which the sensing material 150 may be coupled to or integral with the surface of the object 140, or the sensing material 150 may be located on the inner surface of a ferrule 242 (not shown) that is coupled to or integral with the object 140 to be measured. It will be appreciated that the snap-in features provided by the head portion 66 and protrusions 64 of the probe shaft 40 remain unchanged in the configuration shown in Figure 9, and the details thereof need not be repeated.

[0067] In yet another configuration shown in FIG. 10, a substantially stationary ferrule 342 is shown, with the same snap-in feature provided by the head portion 66 and protrusion 364 of the probe shaft 40, but with a shorter second chamber 360. The shoulder 62 between the first chamber 358 and the shorter second chamber 360 operates in a similar manner as described above, with the head portion 66 being relatively fixed upon insertion. In this configuration, a spring (e.g., spring 46 in FIG. 2) or other biasing member is not required, and this configuration may be preferred in applications where a contact force from such a mechanism is not needed or desired. It is understood that chamber lengths intermediate to those shown in FIGS. 1-10 are contemplated. It is also understood that with respect to FIGS. 1-9, different biasing members may be selected depending on the chamber length selected.

[0068] 11 illustrates another example of a temperature probe 12E having a multi-part ferrule including ferrule parts 42A and 42B. In the illustrated embodiment, the ferrule includes a sliding ferrule part 42A and a rotating ferrule part 42B. The sliding ferrule part 42A is slidable relative to the main body 47, and the rotating ferrule part 42B is rotatable relative to the main body 47. The sliding ferrule part 42A and the rotating ferrule part 42B are coupled to each other using a ball joint 70. In various example embodiments, other types of joints may be used to facilitate allowing the ferrule parts connected to the sensing element 44 to adjust, thereby increasing the contact area between the sensing element 44 and the exposed surface 15 of the object 14.

[0069] 11B, the temperature probe 12E is shown in an adjusted configuration. In FIG. 11B, the ferrule part 42A has been biased by the spring 46 toward the object 14 and is in an adjusted position relative to part 42B. Part 14B adjusts in the passage 17 so that it is not collinear with the optical axis of the main body 47. In FIG. 11B, the angle 1102 between the sensing element 44 and the optical axis of the main body 47 represents the amount of adjustment. Note that in FIG. 11B, the angle 1102 is intentionally exaggerated to promote visual clarity. In various example embodiments, the angle 1102 is less than about 5 degrees, or less than about 3 degrees, or less than about 1 degree.

[0070] In various example embodiments, the rotating ferrule part 42B and the sliding ferrule part 42A have at least one snap or screw or other fastening feature that allows installation into the main body 47 and then restrains the ferrule parts 42A, 42B to the main body 47 after installation.

[0071] An adjustable ferrule, such as the ferrule 42 shown in FIGS. 11A and 11B, can promote contact between the sensing element 44 and the surface 15 of the object 14, while maintaining a gap 82 to limit thermal conduction between the sensing element 44 and the main body 47 and probe 12E.

[0072] For simplicity and clarity of illustration, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or similar elements. Additionally, numerous specific details have been set forth in order to provide a thorough understanding of the examples described herein. However, it will be understood by those skilled in the art that the examples described herein may be practiced without these specific details. In other instances, well-known methods, procedures and components have not been described in detail so as not to obscure the examples described herein. Additionally, the above description should not be considered as limiting the scope of the examples described herein.

[0073] It will be understood that the examples and corresponding diagrams used herein are for illustrative purposes only. Different configurations and terminology can be used without departing from the principles expressed herein. For example, components and modules can be added, deleted, modified, or arranged with different connections without departing from these principles.

[0074] While the above principles have been described with reference to certain specific embodiments, various modifications thereof will become apparent to those skilled in the art as outlined in the appended claims.

Claims

1. a probe shaft having a first portion with a first projection and a cavity therein for locating a fiber optic cable; a ferrule having a second protrusion, the second protrusion cooperating with the first protrusion to prevent the ferrule and the probe shaft from coming out of an assembled configuration; a biasing member connected to the ferrule and the first portion, the biasing member facilitating displacement between the ferrule and the first portion; a sensing element disposed at a distal end of the ferrule proximate to a surface to be measured, the sensing element configured to interact with light received from the fiber optic cable to measure a temperature of the surface to be measured; 1. A fiber optic temperature sensing probe comprising:

2. 2. The probe of claim 1, wherein the sensing element has threads that snap-fit ​​into the opening in the ferrule or are complementary to threads adjacent the opening in the ferrule.

3. The probe of claim 2 , wherein the opening has a chamfered lip to facilitate a snap-in fit of the sensing element.

4. The probe of claim 1 , wherein the second prong has a chamfered lip for creating a snap-in fit with the first prong.

5. 2. The probe of claim 1, wherein the ferrule includes a first chamber extending from the sensing element into a wider second chamber defining a shoulder, the shoulder restricting movement of the first protrusion toward the sensing element.

6. The probe of claim 5 , wherein a shortest distance between the sensing element and the probe shaft in the optical axis is defined by the shoulder.

7. The probe of claim 1 , wherein the second projection has an inner chamfer for interacting with a rearward shoulder of the first portion to prevent the probe shaft and the ferrule from coming apart.

8. The probe of claim 1 , wherein the ferrule or the sensing element is coupled to the surface to be measured.

9. The probe of claim 1 , wherein a base portion of the probe shaft engages a seal to form a vacuum seal between the probe shaft and the surface being measured.

10. The probe of claim 9 , wherein the base portion of the probe shaft is separable from the first portion.

11. The probe of claim 1 , wherein the ferrule includes at least a first ferrule part and a second ferrule part different from the first ferrule part.

12. The probe of claim 11 , wherein the first ferrule part is rotatable relative to the second ferrule part or rotatable relative to the probe shaft.

13. The probe of claim 1 , further comprising a seal that interacts with a wall and the probe shaft to create a vacuum seal.

14. The probe of claim 1 , wherein the sensing element comprises one or more of diamond, aluminum, copper, gold, nickel or nickel alloy, aluminum nitride, and silicon carbide.

15. The contact area between the sensing element and the ferrule is 2 mm 2 Less than or equal to 1 mm 2 Less than or equal to 0.5 mm 2 Less than or equal to 0.25 mm 2 The probe of claim 1 .

16. 10. The probe of claim 1, wherein the sensing element has a thermal conductivity greater than 20 W / m-1K, or greater than 150 Wm-1 / K, or greater than 225 Wm-1 / K, or greater than 300 Wm-1 / K.

17. The probe of claim 1 , wherein the sensing element has an interior surface configured to interact with light received from the fiber optic cable to measure a temperature of the measured surface.

18. A probe body, A base portion; a body extending from the base and terminating in a head; a passageway extending through the base and the probe body; a fiber optic cable in the passage; a probe body having at least one ferrule having a first opening at a first end that provides a snap-in or threaded fit with the head portion; a biasing member positioned to apply a force to the at least one ferrule towards the surface to be measured; a sensing element located at a second end of the at least one ferrule opposite the first end, the sensing element including a sensing material for interacting with light from the fiber optic cable located within the passageway; 1. A fiber optic temperature sensing system comprising:

19. The system of claim 18 , wherein the sensing material is coupled to the surface being measured.

20. 1. A method of assembling a fiber optic temperature sensing probe, comprising the steps of: providing a first portion and a second portion of a probe shaft, the first portion and the second portion of the probe shaft including a passageway configured to receive a fiber optic cable; Providing a first fiber optic cable and a second fiber optic cable; inserting the first fiber optic cable into the first portion of the probe shaft; inserting the second fiber optic cable into the second portion of the probe shaft; Prepare the blocks, Prepare the cap, connecting the first portion of the probe shaft to the block; connecting the second portion of the probe shaft within the cap; installing the block into the cap to optically align the fiber optic cables of the first portion of the probe shaft and the second portion of the probe shaft, respectively; method.

21. 21. The method of claim 20, wherein connecting the first portion of the probe shaft to the block includes sealing the first portion of the probe shaft to the block with a seal.

22. 21. The method of claim 20, wherein the first portion of the probe shaft includes a ferrule having at least a first ferrule part and a second ferrule part different from the first ferrule part, the first ferrule part being configured to rotate relative to the second ferrule part or to rotate relative to the probe shaft.

23. 21. The method of claim 20, wherein the first portion of the probe shaft includes a ferrule having at least a first ferrule part and a second ferrule part different from the first ferrule part, the first ferrule part configured to rotate relative to the first portion of the probe shaft.

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