Probe assembly and handheld Raman spectrometer

Abstract

The utility model belongs to the technical field of optical detection, and particularly relates to a probe assembly and a handheld Raman spectrometer. The utility model discloses a handheld Raman spectrometer, and aims to solve the problems that a probe of an existing handheld Raman spectrometer can only detect a sample at a short distance, when the sample is a liquid or an animal liver, the sample easily pollutes the interior of the spectrometer, and the probe and an instrument body are fixedly arranged, so that equipment is inconvenient to replace / maintain. The probe assembly includes: a probe including a probe housing; the first end of the connecting seat is detachably connected with the probe shell; the connecting end of the optical fiber assembly is connected with the second end of the connecting seat, and the detecting end is used for detecting a to-be-detected sample; the optical fiber assembly comprises an optical fiber coupled with the probe. The connecting seat is detachably connected with the probe, so that the optical fiber assembly is convenient to replace / maintain; the optical fiber is coupled with the probe, and the Raman spectrometer can remotely detect the to-be-detected sample through the optical fiber, so that the to-be-detected sample is effectively prevented from polluting the instrument, the optical signal transmission loss can be effectively reduced, and the detection precision of the instrument is improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to optical detection technical field, concretely relates to a kind of probe assembly and hand-held Raman spectrometer. BACKGROUND

[0002] The probe of hand-held Raman spectrometer usually adopts fixed design, i.e. the probe is integrated with the main body of spectrometer. Although this design is simple in structure, it has the following shortcomings: poor flexibility and inconvenient maintenance. Specifically, the probe is fixedly connected with the main body of spectrometer, and it is difficult to adapt to complex detection environment, for example, narrow space makes the spectrometer unable to be embedded for detection; or, since the hand-held spectrometer is used to detect solution and animal offal, the close detection mode of directly connecting the probe with the spectrometer often causes sample to contaminate the instrument, seriously affecting subsequent detection operation. Meanwhile, when the probe is damaged or contaminated, it needs to be disassembled and repaired as a whole, increasing use cost and time.

[0003] Therefore, the utility model is provided. CONTENT OF UTILITY MODEL

[0004] One purpose of the utility model is to provide a fiber coupling probe assembly capable of remote detection, so that the fiber assembly and the probe are detachably connected, effectively avoiding contamination of the instrument by the sample to be detected.

[0005] To achieve the above purpose, the utility model provides a probe assembly of hand-held Raman spectrometer, comprising:

[0006] a probe, comprising a probe shell;

[0007] a connecting seat, which is detachably connected with the probe shell at the first end;

[0008] a fiber assembly, the connecting end of the fiber assembly is connected with the second end of the connecting seat, and the detection end of the fiber assembly is used to detect the sample to be detected; the fiber assembly comprises an optical fiber, and the optical fiber is coupled with the probe.

[0009] Further, the fiber assembly comprises an FC interface and an optical fiber, the FC interface is used to be connected with the connecting seat; the center of the connecting seat is provided with a through hole, and the connecting end of the optical fiber passes through the center of the FC interface, the through hole and the center of the probe in sequence in alignment.

[0010] Further, the FC interface comprises an interface shell, and the connecting seat further comprises a positioning shaft, which is formed by extending outward from the second end of the connecting seat; the outer side of the positioning shaft and the inner side of the interface shell are both provided with threaded structures, and the threaded structures on the positioning shaft and the interface shell are matched and tightened to fixedly connect the connecting seat with the fiber assembly.

[0011] Further, the FC interface comprises an interface inner shell, which is arranged concentrically with the interface outer shell, and the diameter of the interface inner shell is smaller than that of the interface outer shell; the FC positioning groove is arranged on the interface inner shell, and the positioning protrusion is arranged on the connecting seat; the positioning protrusion can be clamped with the FC positioning groove to fix and connect the optical fiber assembly and the connecting seat.

[0012] Further, the guide column is formed by extending from the connecting seat to the side of the optical fiber assembly, the guide column is arranged concentrically with the positioning shaft, and the diameter of the guide column is smaller than that of the positioning shaft; the guide column is used to allow the connecting end N of the optical fiber to pass through.

[0013] Further, the first end of the connecting seat extends outward to form a connecting groove, and the probe assembly further comprises a clamping structure, the clamping structure comprises a first clamping structure and a second clamping structure, the first clamping structure is arranged on the outside of the probe shell, and the second clamping structure is arranged on the inside of the connecting groove; the first clamping structure is clamped with the second clamping structure to fix and connect the probe shell and the connecting seat.

[0014] Further, the first end of the connecting seat extends outward to form a connecting groove, and the probe assembly further comprises a magnetic attraction assembly, the magnetic attraction assembly comprises a first magnetic attraction device and a second magnetic attraction device, the outside of the probe shell is provided with the first magnetic attraction device, and the inside of the connecting seat is provided with the second magnetic attraction device; the first magnetic attraction device and the second magnetic attraction device are attracted to fix and connect the probe shell and the connecting seat.

[0015] Further, the outside of the probe shell is provided with a first accommodating groove for accommodating the first magnetic attraction device, and the inside of the connecting seat is provided with a second accommodating groove for accommodating the second magnetic attraction device.

[0016] Further, the probe further comprises a lens assembly, which is arranged in the probe shell, and the lens assembly is used to focus a light beam to the end face of the optical fiber.

[0017] Further, the optical fiber assembly further comprises a ferrule, which is connected with the optical fiber, and one end of the ferrule is in contact with the sample to be measured, and the other end of the ferrule is coincident with the focal point of the lens assembly and is arranged concentrically with the ferrule for contacting the sample to be measured.

[0018] Further, the ferrule is made of iron or ceramic material.

[0019] Further, the lens in the lens assembly is a non-spherical lens, a double-cemented lens, a concave-convex single lens, or an off-axis parabolic reflector.

[0020] In other embodiments, a handheld Raman spectrometer is provided, comprising a spectrometer body and the handheld Raman spectrometer probe assembly of any of the above.

[0021] Based on the foregoing description, those skilled in the art can understand that, in the technical solutions of the foregoing embodiments of the present application, the connecting seat is detachably connected with the probe, and the optical fiber is connected with the connecting seat, so that the operator can replace the optical fiber assembly, and in addition, in detection experiments, the optical fiber assembly can be directly replaced to detect different types of samples, thereby reducing equipment downtime and improving overall detection efficiency; the optical fiber is coupled with the probe, and the Raman spectrometer can detect the sample to be detected at a distance through the optical fiber, effectively avoiding pollution of the sample to be detected to the instrument, effectively reducing loss of optical signal transmission, and improving detection accuracy.

[0022] Further, the standardized FC interface and the lightweight material reduce manufacturing and maintenance costs.

[0023] Further, the probe assembly of the present application is compact in design, light in weight, convenient to carry and operate, and suitable for on-site rapid detection. BRIEF DESCRIPTION OF DRAWINGS

[0024] The accompanying drawings are part of the present application and serve to provide a further understanding of the present application, and the illustrative embodiments of the present application and the description thereof serve to explain the present application, but do not constitute an improper limitation on the present application. Obviously, the drawings described below are only some embodiments, and other drawings can be obtained by those skilled in the art without creative labor. In the drawings:

[0025] Figure 1 is a structural schematic view of the probe assembly in some embodiments of the present application;

[0026] Figure 2 is Figure 1 is a sectional view of the probe assembly along the A-A direction in some embodiments of the present application;

[0027] Figure 3 is Figure 1 is a partial structural schematic view of the optical fiber assembly and the connecting seat in some embodiments of the present application;

[0028] Figure 4 is Figure 2 is a schematic view of the first embodiment of the lens assembly in some embodiments of the present application;

[0029] Figure 5 is Figure 2 is a schematic view of the second embodiment of the lens assembly in some embodiments of the present application;

[0030] Figure 6 is Figure 2Schematic view of a third embodiment of the middle lens assembly;

[0031] Figure 7 For Figure 2 Schematic view of a fourth embodiment of the middle lens assembly;

[0032] Figure 8 For the structure diagram of the handheld Raman spectrometer in other embodiments of the utility model. BRIEF DESCRIPTION OF DRAWINGS

[0034] 100, handheld Raman spectrometer;

[0035] 1, spectrometer body;

[0036] 2, probe assembly; 21, probe; 211, probe shell; 212, lens assembly; 22, optical fiber assembly; M, optical fiber assembly detection end; N, optical fiber assembly connecting end; 221, FC interface; 2211, interface shell; 2212, interface inner shell; 2213, FC positioning protrusion; 222, optical fiber; 23, connecting seat; 231, seat body; 232, positioning shaft; 2321, U-shaped groove; 233, guide column; 234, positioning groove. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model more clear, the technical scheme in the embodiments will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model, and the following embodiments are used to illustrate the utility model, but not to limit the scope of the utility model.

[0038] In the description of the utility model, it should be explained that the orientation or position relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "inner", "outer" and the like is the orientation or position relationship based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, therefore, it cannot be understood as a limitation on the utility model.

[0039] In the description of the utility model, it should be explained that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0040] The following will be described with reference to Figures 1 to 8, to make a detailed description of the structure of the probe assembly and the handheld Raman spectrometer in some embodiments of the present application. Among them, Figure 1 It is a structural schematic diagram of the probe assembly in some embodiments of the present application. Figure 2 It is Figure 1 It is a sectional view of the probe assembly along the A-A direction in the present application. Figure 3 It is Figure 1 It is a partial structural schematic diagram of the optical fiber assembly and the connecting seat in the present application. Figure 4 It is Figure 2 It is a schematic diagram of the first embodiment of the lens assembly in the present application. Figure 5 It is Figure 2 It is a schematic diagram of the second embodiment of the lens assembly in the present application. Figure 6 It is Figure 2 It is a schematic diagram of the third embodiment of the lens assembly in the present application. Figure 7 It is Figure 2 It is a schematic diagram of the fourth embodiment of the lens assembly in the present application. Figure 8 It is a structural schematic diagram of the handheld Raman spectrometer in other embodiments of the present application.

[0041] As shown in Figure 1 and Figure 2 In some embodiments of the present application, a probe assembly 2 of a handheld Raman spectrometer 100 is provided, which comprises a probe 21, an optical fiber assembly 22 and a connecting seat 23. The probe 21 is coupled with an optical fiber 222 in the optical fiber assembly 22 through the connecting seat 23, so as to realize detection of a sample to be detected. In the present application, the probe 21 is arranged on the outside of the handheld Raman spectrometer 100, that is, the probe 21 comprises a probe shell 211 which is formed by extending outward from the Raman spectrometer shell. The connecting seat 23 is detachably connected with the probe 21, so that an operator can quickly replace / detach the optical fiber assembly 22 according to actual detection requirements.

[0042] Among them, the probe shell 211 is made of light aluminum alloy material.

[0043] The probe 21 further comprises a lens assembly 212, which is arranged in the probe shell 211 and is used for focusing a light beam to the end face of the optical fiber 222, and then converging the light beam to the surface of a sample by the optical fiber 222. The Raman signal returned by the sample is coupled through the optical fiber 222 and the lens assembly 212 in turn, and then returned to an analysis module in the spectrometer, and the spectrometer analyzes and detects the signal.

[0044] The lens assembly 212 in the handheld Raman spectrometer 100 in the present application includes but is not limited to the following examples:

[0045] As shown in Figure 4As shown in the preferred example one, the lenses in the lens assembly 212 are all set as aspheric lenses, and the parameters of the aspheric lenses are configured as a diameter of 6.35mm, a focal length of 15mm, and a material of fused silica.

[0046] As shown in the example two, the lens assembly 212 is set as a doublet lens, and the parameters of the doublet lens are configured as a diameter of 12.7mm and a focal length of 19mm. Figure 5

[0047] As shown in the example three, the lens assembly 212 is set as a meniscus lens, and the parameters of the meniscus lens are configured as a diameter of 20mm and a focal length of 30mm. Figure 6

[0048] As shown in the example four, the lenses in the lens assembly 212 are set as off-axis parabolic mirrors, and the parameters of the off-axis parabolic mirrors are configured as a diameter of 12.7mm, a focal length of 25.4mm, and a material of silver base. Figure 8

[0049] The handheld Raman spectrometer 100 in the utility model mainly aims at detecting the chemical components of some mixed solutions and the chemical components of the cells in the stomach of animals which need to be non-destructively tested, and thus it is required that the volume of the detection sample end is small and can be transmitted over a long distance to avoid the problem that the detection end M is in contact with the sample to be detected after short-distance transmission, thereby causing pollution of the equipment.

[0050] Since the volume of the optical fiber 222 is small, the overall volume of the equipment is small, and the optical fiber 222 is suitable for long-distance transmission, thereby effectively avoiding the problem of equipment pollution; at the same time, the signal attenuation in the optical fiber 222 is small, thereby reducing experimental errors.

[0051] As shown in the example two, the lens assembly 212 is set as a doublet lens, and the parameters of the doublet lens are configured as a diameter of 12.7mm and a focal length of 19mm. Figure 3 ​​​As shown, the connecting end N of the fiber assembly 22 is coupled with the probe 21, and the detecting end M of the fiber assembly 22 is used for detecting the sample to be measured. The fiber assembly 22 comprises an FC interface 221, an optical fiber 222 and a ferrule (not shown in the figure), and the FC interface 221 is used for connecting with the connecting seat 23. The connecting seat 23 is provided with a through hole at the center position, and the connecting end N of the optical fiber 222 is sequentially aligned with the center of the FC interface 221, the through hole and the center of the probe 21 or the lens assembly 212 in the probe 21.

[0052] The FC interface 221 comprises an interface outer shell 2211 and an interface inner shell 2212, the interface inner shell 2212 is concentrically arranged with the interface outer shell 2211, and the diameter of the interface inner shell 2212 is smaller than the diameter of the interface outer shell 2211.

[0053] The connecting seat 23 further comprises a seat body 231, a positioning shaft 232 and a guide column 233, and the positioning shaft 232 is formed by extending outward from the second end of the seat body 231 of the connecting seat 23. The outer side of the positioning shaft 232 and the inner side of the interface outer shell 2211 are both provided with threaded structures, and the threaded structures on the positioning shaft 232 and the interface outer shell 2211 are matched and tightened to fixedly connect the connecting seat 23 with the fiber assembly 22.

[0054] The interface inner shell 2212 is provided with an FC positioning groove 2213, and the connecting seat 23 is provided with a positioning protrusion 234, which can be clamped with the FC positioning groove 2213 to fixedly connect the fiber assembly 22 with the connecting seat 23. The operator can complete the installation / dismantling of the fiber assembly 22 with the connecting seat 23 through plug-in / plug-out operation, which can also avoid the problem of loosening at the connection between the fiber assembly 22 and the connecting seat 23, and make the handheld Raman spectrometer 100 have a certain vibration resistance.

[0055] The guide column 233 is formed by extending from the connecting seat 23 to one side of the fiber assembly 22, and the guide column 233 is concentrically arranged with the positioning shaft 232, and the diameter of the guide column 233 is smaller than that of the positioning shaft 232. The guide column 233 is used for allowing the connecting end N of the optical fiber 222 to pass through.

[0056] The positioning shaft 232 is further provided with a "U"-shaped groove 2321, which plays a role of giving way, and can avoid scratching the surface of the optical fiber 222 by the edge of the positioning shaft 232 during the disassembly of the fiber assembly 22.

[0057] The fiber assembly 22 further comprises a ferrule, which is fixedly connected with the optical fiber 222 through curing glue, one end of the ferrule is in contact with the sample to be measured, and the other end is coaxially arranged with the focal point of the lens assembly 212.

[0058] The ferrule is made of iron material or ceramic material. Preferably, the ferrule is made of ceramic material.

[0059] To avoid sample contamination of the instrument, the length of the optical fiber 222 can be set to 50 cm to 150 cm. In some embodiments, the length of the optical fiber 222 can be set to 50 cm, 60 cm, 70 cm, 80 cm, 90 cm, 100 cm, 110 cm, 12 cm, 130 cm, 140 cm, or 150 cm, etc. In some more specific embodiments, the length of the optical fiber 222 is set to 100 cm; and the ferrule inner diameter is set to 600 um, with a wavelength of 400-2500 nm.

[0060] The center of the connecting seat 23 is provided with a through hole for the transmission of the light beam. The first end of the connecting seat 23 is detachably connected with the probe shell 211, and the second end is connected with the connecting end N of the optical fiber assembly 22. The first end of the connecting seat 23 extends outwardly to form a connecting groove.

[0061] The connecting seat 23 further comprises a guide column 233, which is a hollow structure and extends from the edge of the through hole to the side of the optical fiber assembly 22. The optical fiber 222 can pass through the guide column 233 to align with the center of the probe 21.

[0062] The connecting seat 23 is integrally formed by the injection molding process.

[0063] In other embodiments of the present application, the probe assembly 2 further comprises a clamping structure (not shown in the figure), which comprises a first clamping structure and a second clamping structure. The first clamping structure is arranged on the outside of the probe shell 211, and the second clamping structure is arranged on the inside of the connecting groove. The first clamping structure and the second clamping structure are clamped to fixedly connect the probe shell 211 and the connecting seat 23.

[0064] In other embodiments of the present application, the probe assembly 2 further comprises a magnetic attraction assembly (not shown in the figure), which comprises a first magnetic attraction device and a second magnetic attraction device. The outside of the probe shell 211 is provided with the first magnetic attraction device, and the inside of the connecting seat 23 is provided with the second magnetic attraction device. The first magnetic attraction device and the second magnetic attraction device are attracted to fixedly connect the probe shell 211 and the connecting seat 23.

[0065] In the present embodiment, the outside of the probe shell 211 is provided with a first accommodating groove for accommodating the first magnetic attraction device. The inside of the connecting seat 23 is provided with a second accommodating groove for accommodating the second magnetic attraction device.

[0066] Among them, the connection mode of the magnetic attraction assembly with the connecting seat 23 and the probe shell 211 can be set as the following examples:

[0067] Example one, in the process of injection molding of the connecting seat 23, the second magnetic attraction device is embedded in the inside of the connecting seat 23 to be integrally formed.

[0068] In the second example, the edge of the first accommodating groove and the edge of the second accommodating groove are pivotally connected with the corresponding cover bodies, and the edge of each cover body is provided with a buckle, so that the operator can clamp each cover body with the corresponding buckle to cover each cover body.

[0069] In the third example, the first magnetic attraction device and the second magnetic attraction device are fixedly connected with the bottom wall of the first accommodating groove and the bottom wall of the second accommodating groove through adhesion.

[0070] As Figure 8 In other embodiments of the utility model, a handheld Raman spectrometer 100 is also provided, which comprises a spectrometer body 1 and the probe assembly 2 of the handheld Raman spectrometer 100 according to any one of the above.

[0071] The skilled in the art can understand that, by detachably connecting the connecting seat 23 with the probe 21 and connecting the optical fiber 222 with the connecting seat 23, the operator can replace the optical fiber assembly 22, and in addition, in the detection experiment, the optical fiber assembly 22 can be directly replaced to detect different kinds of samples, so that the equipment downtime is reduced and the overall detection efficiency is improved; the optical fiber 222 is coupled with the probe 21, and the Raman spectrometer can remotely detect the sample to be detected through the optical fiber 222, so that the sample to be detected can effectively avoid polluting the instrument, the optical signal transmission loss can be effectively reduced, and the detection precision is improved.

[0072] Further, by using the standardized FC interface 221 and the light material, the manufacturing and maintenance costs are reduced.

[0073] Further, the probe assembly 2 of the utility model is compact in design and light in weight, and is convenient to carry and operate, and is suitable for on-site rapid detection.

[0074] The above is only a preferred embodiment of the utility model, and does not limit the utility model in any form, although the utility model has been disclosed as above, however, it is not intended to limit the utility model, any skilled person in the art can make some changes or modifications to the above-mentioned technical content without departing from the technical solution of the utility model, and equivalent embodiments with equivalent changes are equivalent, the implementation schemes in the above-mentioned embodiments can be further combined or replaced, as long as the content of the utility model technical solution is not deviated, any simple modification, equivalent change and modification of the above-mentioned embodiments according to the technical essence of the utility model are still within the scope of the utility model.

Claims

1. A probe assembly for a handheld Raman spectrometer, the probe assembly comprising: The probe comprises a probe shell, a connecting seat, and a fiber assembly. The first end of the connecting seat is detachably connected with the probe shell. The connecting end of the fiber assembly is connected with the second end of the connecting seat, and the detection end of the fiber assembly is used for detecting a sample to be detected. The fiber assembly comprises an FC interface and a fiber.

2. The probe assembly of the handheld Raman spectrometer according to claim 1, wherein the fiber assembly comprises an FC interface and a fiber, and the FC interface is used for connecting with the connecting seat. The center of the connecting seat is provided with a through hole, and the connecting end of the fiber sequentially passes through the center of the FC interface, the through hole, and the center of the probe.

3. The probe assembly of the handheld Raman spectrometer according to claim 2, wherein the FC interface comprises an interface shell, and the connecting seat further comprises a positioning shaft which is formed by extending outward from the second end of the connecting seat. The outer side of the positioning shaft and the inner side of the interface shell are provided with threaded structures, and the threaded structures on the positioning shaft and the interface shell are matched and tightened to fixedly connect the connecting seat with the fiber assembly.

4. The probe assembly of the handheld Raman spectrometer according to claim 3, wherein the FC interface comprises an interface inner shell which is concentrically arranged with the interface shell and has a diameter smaller than that of the interface shell. The interface inner shell is provided with an FC positioning groove, and the connecting seat is provided with a positioning protrusion. The positioning protrusion can be clamped with the FC positioning groove to fixedly connect the fiber assembly with the connecting seat.

5. The probe assembly of the handheld Raman spectrometer according to claim 3, wherein the connecting seat extends to one side of the fiber assembly to form a guide column which is concentrically arranged with the positioning shaft and has a diameter smaller than that of the positioning shaft. The guide column is used for allowing the connecting end N of the fiber to pass through.

6. The probe assembly of the handheld Raman spectrometer according to claim 1, wherein the first end of the connecting seat extends outward to form a connecting groove, The probe assembly further comprises a clamping structure which comprises a first clamping structure and a second clamping structure. The first clamping structure is arranged on the outer side of the probe shell, and the second clamping structure is arranged on the inner side of the connecting groove. The first clamping structure is clamped with the second clamping structure to fixedly connect the probe shell with the connecting seat.

7. The probe assembly of the handheld Raman spectrometer according to claim 1, wherein the first end of the connecting seat extends outward to form a connecting groove, The probe assembly further comprises a magnetic attraction assembly which comprises a first magnetic attraction device and a second magnetic attraction device. The outer side of the probe shell is provided with the first magnetic attraction device, and the inner side of the connecting seat is provided with the second magnetic attraction device. The first magnetic attraction device and the second magnetic attraction device are attracted to fixedly connect the probe shell with the connecting seat.

8. The probe assembly of the handheld Raman spectrometer according to claim 7, wherein ​ ​ ​ ​ ​ An outer side of the probe shell is provided with a first accommodating groove for accommodating the first magnetic attraction device; An inner side of the connecting seat is provided with a second accommodating groove for accommodating the second magnetic attraction device. 9.The probe assembly of the handheld Raman spectrometer according to claim 1, wherein the probe further comprises a lens assembly arranged in the probe shell, the lens assembly being configured to focus a light beam to the end face of the optical fiber. 10.The probe assembly of the handheld Raman spectrometer according to claim 9, wherein the optical fiber assembly further comprises a ferrule connected with the optical fiber, one end of the ferrule being configured to contact a sample to be measured, and the other end of the ferrule being configured to coincide with and concentrically arranged at a focal point of the lens assembly. 11.The probe assembly of the handheld Raman spectrometer according to claim 10, wherein the ferrule is made of iron or ceramic. 12.The probe assembly of the handheld Raman spectrometer according to claim 11, wherein the lens in the lens assembly is a non-spherical lens, a double-cemented lens, a concave-convex single lens, or an off-axis parabolic mirror. A handheld Raman spectrometer comprising a spectrometer body and the probe assembly of any one of claims 1 to 12. ​ ​ ​ 13. A handheld Raman spectrometer, characterized by, ​

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