A small near-infrared spectrometer with high coupling efficiency

Abstract

The present invention discloses a small near-infrared spectrometer with high coupling efficiency, which relates to the technical field of infrared spectrometers and comprises: an equipment housing, wherein a light source chamber, a light guide chamber, a sample chamber and a light receiving chamber are provided inside the equipment housing, and the light source chamber is provided in the middle of the inner side of the equipment housing. The present invention provides the light source chamber, the light guide chamber, the sample chamber and the light receiving chamber, and the light emitted by the light source lamp inside the light source chamber can pass through the light guide chamber, the sample chamber and the light receiving chamber in sequence. Under the guidance of the light guide lens inside the light guide chamber, the light is distributed in parallel and the beam diameter becomes smaller. The parallel light of the small light beam passes through the sample in the sample chamber, and then passes through the linear gradient light transmission sheet and is collected by the photodetector in the light receiving chamber. The parallel light of the small light beam can be better collected by the photodetector, which significantly increases the coupling efficiency of the light. In addition, the light intensity received by the photodetector can be increased, thereby increasing the signal-to-noise ratio of the light, so that the detection limit of the spectrometer is significantly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of infrared spectrometers, in particular to a small near-infrared spectrometer with high coupling efficiency. Background Art

[0002] A near-infrared spectrometer is an instrument used to analyze samples. It uses near-infrared spectroscopy to obtain information about the samples.

[0003] In existing small near-infrared spectrometers, a linear gradient light-transmitting sheet is usually used in conjunction with a linear detector array. Different positions on the plane of the linear gradient light-transmitting sheet correspond to different unit detectors of the linear detector array, that is, different unit detectors of the linear detector array detect different transmission wavelengths. However, in the above structure, the light emitted by the light source needs to irradiate the entire plane of the linear gradient light-transmitting sheet, resulting in a very low light coupling efficiency, that is, each unit detector only receives a very small part of the light from the light source, which reduces the signal-to-noise ratio of the spectrometer and affects the detection limit of the spectrometer. Moreover, the existing near-infrared spectrometer is limited by its structural design and can only realize the analysis of a single sample in actual application. Moreover, when the light source is damaged due to problems such as expiration of its life during use, the replacement of the light source is relatively cumbersome, which is not conducive to the sample analysis work.

[0004] Therefore, it is necessary to invent a small near-infrared spectrometer with high coupling efficiency to solve the above problems. Summary of the Invention

[0005] The object of the present invention is to provide a small near-infrared spectrometer with high coupling efficiency to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solution: a small near-infrared spectrometer with high coupling efficiency, comprising:

[0007] The device housing has a light source chamber, a light guide chamber, a sample chamber, and a light receiving chamber inside. The light source chamber is located in the middle of the inner side of the device housing. The light guide chamber, the sample chamber, and the light receiving chamber are each provided with two groups. The two groups of light guide chambers, sample chambers, and light receiving chambers are respectively arranged horizontally on both sides of the light source chamber and are symmetrically distributed.

[0008] A fixed cover is fixedly provided at the middle of the outer wall of the light source chamber, and a light source lamp is detachably plugged into the interior of the fixed cover;

[0009] A light guide tube is fixedly provided inside the light guide chamber, and both ends of the light guide tube are respectively connected to the light source chamber and the sample chamber. A light guide lens is fixedly provided inside the light guide tube, and the light guide lens is a convex lens.

[0010] A sample box is provided in the sample chamber;

[0011] A photoelectric detector and a linear gradient light-transmitting sheet are provided inside the light-receiving chamber. The photoelectric detector is fixed on the inner wall of the light-receiving chamber away from the sample chamber, and the linear gradient light-transmitting sheet is slidably provided inside the light-receiving chamber.

[0012] Preferably, a light guide cover is fixedly provided inside the light source chamber, the light guide cover is set to a ring structure, and a socket compatible with the light source lamp is penetrated through the middle of the outer wall of the light guide cover, and focusing cups are fixed on both sides of the light guide cover, and the focusing cups are set to a trumpet-shaped structure. The inner side surfaces of the focusing cups and the light guide cover are both provided with reflective coatings, and light-guiding glass beads are fixed on the ends of the two focusing cups away from each other, and one side of the two light-guiding glass beads extends to the interior of the two light guide chambers respectively.

[0013] Preferably, a pressure seat is detachably plugged into one end of the fixed cover, and a mounting seat is rotatably provided at one end of the pressure seat through a bearing, and the mounting seat is threadedly provided at one end of the fixed cover.

[0014] Preferably, a fixing sleeve is fixedly provided inside the light receiving chamber, a sliding seat is rotatably provided inside the fixing sleeve, and the linear gradient light-transmitting sheet is fixedly provided in the middle of the sliding seat.

[0015] Preferably, movable seats are fixed on both sides of the sliding seat, and strip-shaped structure slide grooves are penetrated on both sides of the fixed sleeve. The two movable seats are slidably arranged inside the two slide grooves, and sealing covers are fixed at the notches of the two slide grooves. The two movable seats are respectively arranged inside the two sealing covers.

[0016] Preferably, the interiors of the two sealing covers are rotatably provided with threaded rods via bearings, the middle portions of the two movable seats are penetrated by threaded grooves, and the two threaded rods are respectively threadedly provided inside the two threaded grooves.

[0017] Preferably, a transmission gear is fixedly provided at one end of the two threaded rods, a driving gear is rotatably provided at one end of the outer wall of the fixed sleeve through a bearing, and the driving gear is engaged with the transmission gear, a turntable is fixedly provided on the inner side of the driving gear, and a plurality of anti-slip grooves are provided around the outer wall of the turntable, a through groove is penetrated by the outer side surface of the light receiving chamber, and the position of the through groove corresponds to the turntable.

[0018] Preferably, light-transmitting plates are provided on both sides of the sample box, and the positions of the light-transmitting plates coincide with the light guide tubes.

[0019] Preferably, an end plate is fixedly provided at one end of the sample box, and the end plate is connected to the outer wall of the device housing by magnetic attraction.

[0020] Preferably, a liquid guide cover is fixedly provided inside the sample box, and the liquid guide cover is arranged between two light-transmitting plates, cavities are provided at both ends of the interior of the liquid guide cover, a plurality of capillaries are provided between the two cavities, a liquid inlet pipe is fixedly provided at the top of the cavity located above, a peristaltic pump is fixedly provided at one end of the peristaltic pump, a catheter is fixedly provided at one end of the catheter, two liquid inlets are fixedly provided at one end, and the two liquid inlets are respectively arranged on the outer wall of the sample box, a solenoid valve is fixedly provided between the two liquid inlets and the catheter, a liquid discharge pipe is fixedly provided at the bottom end of the cavity located below, and one end of the liquid discharge pipe is arranged on the outer wall of the sample box.

[0021] Technical effects and advantages of the present invention:

[0022] 1. The present invention provides a light source chamber, a light guide chamber, a sample chamber, and a light receiving chamber. The light emitted by the light source lamp inside the light source chamber can sequentially pass through the light guide chamber, the sample chamber, and the light receiving chamber. Under the guidance of the light guide lens inside the light guide chamber, the light is distributed in parallel and the beam diameter becomes smaller. The parallel light of the small beam passes through the sample in the sample chamber, and then passes through the linear gradient light transmittance sheet and is collected by the photodetector in the light receiving chamber. The parallel light of the small beam can be better collected by the photodetector, significantly increasing the light coupling efficiency. In addition, the light intensity received by the photodetector can be increased, thereby increasing the signal-to-noise ratio of the light, so that the detection limit of the spectrometer is significantly improved.

[0023] 2. The present invention is provided with a light source chamber, a light guide chamber, a sample chamber and a light receiving chamber. The light guide chamber, the sample chamber and the light receiving chamber are each provided with two groups and are symmetrically arranged on both sides of the light source chamber. The light emitted by the light source lamp in the light source chamber is guided by the light guide cover and the focusing cup to light up the light guide glass beads. After being lit, the light guide glass beads evenly disperse the light into the light guide chamber. The evenly dispersed light is flatly distributed after being guided by the light guide lens. The light guide glass beads and the light guide lens can realize the analysis of two groups of samples through a set of light source lamps, which significantly improves the analysis efficiency of the device. In addition, the light source lamp is installed in the light source chamber by plug-in installation, and can be quickly replaced when it is damaged.

[0024] 3. The present invention provides a fixed sleeve and a slide, and the linear gradient light-transmitting sheet is provided in the middle of the slide, and the slide can slide in the fixed sleeve. By adjusting the position of the slide, the position of the linear gradient light-transmitting sheet can be adjusted, so that the wavelength corresponding to the light passing through the linear gradient light-transmitting sheet changes, so that the photoelectric detector can receive light of different wavelengths. When analyzing different samples, considering that different wavelengths of light have different penetration effects on different samples, the wavelength of light received by the photoelectric detector can be adjusted by adjusting the linear gradient light-transmitting sheet to ensure the analysis accuracy of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0026] Figure 2 It is a schematic diagram of the overall structure of the present invention.

[0027] Figure 3 It is a side sectional schematic diagram of the overall structure of the present invention.

[0028] Figure 4 It is a schematic diagram of the internal structure of the overall structure of the present invention.

[0029] Figure 5 It is a schematic cross-sectional view of the overall structure of the present invention.

[0030] Figure 6 It is a schematic diagram of the internal light trajectory of the overall structure of the present invention.

[0031] Figure 7 It is a structural schematic diagram of the fixing sleeve of the present invention.

[0032] Figure 8 It is a schematic diagram of the slide structure of the present invention.

[0033] Figure 9 It is a schematic cross-sectional view of the sample box structure of the present invention.

[0034] In the figure: 1. Equipment housing; 2. Light source chamber; 3. Light guide chamber; 4. Sample chamber; 5. Light receiving chamber; 6. Display panel; 21. Fixing cover; 22. Light source lamp; 23. Light guide cover; 24. Focusing cup; 25. Light guide glass beads; 26. Pressing seat; 27. Mounting seat; 31. Light guide tube; 32. Light guide lens; 41. Sample box; 42. Transparent plate; 421. Liquid guide cover; 422. Cavity; 423. Capillary; 424. Inlet Liquid pipe; 425, peristaltic pump; 426, catheter; 427, liquid inlet; 428, solenoid valve; 429, discharge pipe; 44, end plate; 51, photoelectric detector; 52, linear gradient light-transmitting sheet; 53, fixed sleeve; 54, slide seat; 55, movable seat; 551, threaded groove; 56, slide groove; 57, sealing cover; 58, threaded rod; 581, transmission gear; 582, drive gear; 583, turntable; 584, through groove. DETAILED DESCRIPTION

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0036] like Figures 1 to 9As shown, a small-sized near-infrared spectrometer with high coupling efficiency provided by the present invention is essentially a spectrometer with a parallel optical path inside. By arranging a light source chamber 2, a light guide chamber 3, a sample chamber 4 and a light receiving chamber 5, the light emitted by the light source lamp 22 inside the light source chamber 2 can pass through the light guide chamber 3, the sample chamber 4 and the light receiving chamber 5 in sequence. Under the guidance of the light guide lens 32 inside the light guide chamber 3, the light is distributed in parallel and the beam diameter becomes smaller. The parallel light with a small beam diameter passes through the sample in the sample chamber 4, and then passes through the linear gradient transparent sheet 52 and is collected by the photodetector 51 in the light receiving chamber 5. The parallel light with a small beam diameter can be better collected by the photodetector 51, which significantly increases the light coupling efficiency. In addition, the light intensity received by the photodetector 51 can be increased, thereby increasing the signal-to-noise ratio of the light, so that the detection limit of the spectrometer is significantly improved.

[0037] The light guide chamber 3, the sample chamber 4 and the light receiving chamber 5 are each provided with two groups, and are symmetrically arranged on both sides of the light source chamber 2. The light emitted by the light source lamp 22 in the light source chamber 2 is guided by the light guide cover 23 and the focusing cup 24 to light up the light guide glass beads 25. After being lit, the light guide glass beads 25 evenly diverge the light into the light guide chamber 3. The evenly diverged light is flatly distributed after being guided by the light guide lens 32. The light guide glass beads 25 and the light guide lens 32 can realize the analysis of two groups of samples through a set of light source lamps 22, which significantly improves the analysis efficiency of the device. In addition, the light source lamp 22 is installed in the light source chamber 2 by plug-in installation, and can be quickly replaced when it is damaged.

[0038] When analyzing different samples, considering that different wavelengths of light have different penetrating effects on different samples, the wavelength of light received by the photodetector 51 can be adjusted by adjusting the position of the linear gradient light-transmitting sheet 52 to ensure the analysis accuracy of the device.

[0039] In terms of specific structural installation, the structural body can be constructed according to the inventive concept of this embodiment, and no special limitation is made in this embodiment.

[0040] In this embodiment, a small near-infrared spectrometer with high coupling efficiency includes:

[0041] The device housing 1 has a light source chamber 2, a light guide chamber 3, a sample chamber 4, and a light receiving chamber 5 inside. The light source chamber 2 is located in the middle of the inner side of the device housing 1. The light guide chamber 3, the sample chamber 4, and the light receiving chamber 5 are each provided with two groups. The two groups of light guide chambers 3, sample chambers 4, and light receiving chambers 5 are horizontally arranged on both sides of the light source chamber 2 and are symmetrically distributed.

[0042] A fixed cover 21 is fixedly provided in the middle of the outer wall of the light source chamber 2. A light source lamp 22 is detachably inserted into the interior of the fixed cover 21. The light source lamp 22 is a tungsten lamp that can emit near-infrared rays to facilitate analysis.

[0043] A light guide cover 23 is fixedly provided inside the light source chamber 2. The light guide cover 23 is an annular structure, and a socket adapted for the light source lamp 22 is provided through the middle of the outer wall of the light guide cover 23. Focusing cups 24 are fixedly provided on both sides of the light guide cover 23. The focusing cups 24 are a trumpet-shaped structure. The inner sides of the focusing cups 24 and the light guide cover 23 are provided with a reflective coating. A light-guiding glass bead 25 is fixedly provided on one end of the two focusing cups 24 away from each other. One side of the two light-guiding glass beads 25 extends into the interior of the two light guide chambers 3 respectively.

[0044] One end of the fixed cover 21 is detachably connected to a pressure seat 26, and one end of the pressure seat 26 is rotatably provided with a mounting seat 27 through a bearing. The mounting seat 27 is threadedly provided on one end of the fixed cover 21. It should be noted that a conductive socket is provided on the inner side of the pressure seat 26, and the conductive socket is connected to the power supply of the device through a wire. An electrode is provided at one end of the light source lamp 22. When the pressure seat 26 presses the light source lamp 22 into the fixed cover 21, the conductive socket is combined with the electrode to connect the light source lamp 22 to the circuit of the device.

[0045] A light pipe 31 is fixedly provided inside the light guide chamber 3. The two ends of the light pipe 31 are respectively connected to the light source chamber 2 and the sample chamber 4. A light guide lens 32 is fixedly provided inside the light guide chamber 31. The light guide lens 32 is a convex lens. The light guide lens 32 is a quartz lens. Quartz has good transmittance in the near-infrared band to reduce the loss of light power.

[0046] A sample box 41 is provided in the sample chamber 4;

[0047] An end plate 44 is fixedly provided at one end of the sample box 41. The end plate 44 is connected to the outer wall of the device housing 1 by magnetic attraction. The magnetic attraction facilitates the installation and fixation of the sample box 41.

[0048] A light-transmitting plate 42 is provided on both sides of the sample box 41, and the position of the light-transmitting plate 42 coincides with the light guide tube 31. A liquid-guiding cover 421 is fixedly provided inside the sample box 41, and is disposed between the two light-transmitting plates 42. A cavity 422 is provided at each end of the liquid-guiding cover 421, and a plurality of capillaries 423 are disposed between the two cavities 422. The diameter of the capillaries 423 is approximately the same as the diameter of the parallel thin light beam after being refracted by the light-guiding lens 32.

[0049] A liquid inlet pipe 424 is fixedly provided at the top of the upper cavity 422, a peristaltic pump 425 is fixedly provided at one end of the liquid inlet pipe 424, a catheter 426 is fixedly provided at one end of the peristaltic pump 425, two liquid inlets 427 are fixedly provided at one end of the catheter 426, and the two liquid inlets 427 are respectively provided on the outer wall of the sample box 41, a solenoid valve 428 is fixedly provided between the two liquid inlets 427 and the catheter 426, and a liquid discharge pipe 429 is fixedly provided at the bottom end of the lower cavity 422, and one end of the liquid discharge pipe 429 is provided on the outer wall of the sample box 41;

[0050] A photodetector 51 and a linear gradient light-transmitting sheet 52 are provided inside the light-receiving chamber 5. The photodetector 51 is fixedly mounted on the inner wall of the light-receiving chamber 5 away from the sample chamber 4. The linear gradient light-transmitting sheet 52 is slidably mounted inside the light-receiving chamber 5. The transmission wavelength of the linear gradient light-transmitting sheet 52 varies linearly along the plane of the linear gradient light-transmitting sheet 52. When the position of the linear gradient light-transmitting sheet 52 is adjusted, the transmission wavelength at the corresponding position changes, and the corresponding light data acquired by the photodetector 51 changes.

[0051] A fixed sleeve 53 is fixed inside the light receiving chamber 5, a slide 54 is rotatably provided inside the fixed sleeve 53, and a linear gradient light-transmitting sheet 52 is fixed in the middle of the slide 54;

[0052] A movable seat 55 is fixed on both sides of the slide seat 54. A strip-shaped slide groove 56 is provided on both sides of the fixed sleeve 53. The two movable seats 55 are slidably arranged inside the two slide grooves 56. A sealing cover 57 is fixed at the notch of the two slide grooves 56. The two movable seats 55 are respectively arranged inside the two sealing covers 57. The sealing covers 57 are used to prevent light from leaking from the fixed sleeve 53.

[0053] The interiors of the two sealing covers 57 are rotatably provided with threaded rods 58 via bearings. The middle portions of the two movable seats 55 are penetrated by threaded grooves 551. The two threaded rods 58 are respectively threadedly provided in the interiors of the two threaded grooves 551.

[0054] One end of each of the two threaded rods 58 is fixed with a transmission gear 581. One end of the outer wall of the fixed sleeve 53 is rotatably provided with a driving gear 582 through a bearing, and the driving gear 582 is meshed with the transmission gear 581. A turntable 583 is fixed to the inner side of the driving gear 582, and a plurality of anti-slip grooves are arranged around the outer wall of the turntable 583. A through slot 584 is formed through the outer side of the light receiving chamber 5, and the position of the through slot 584 corresponds to that of the turntable 583. The provision of the through slot 584 makes it convenient for the user to adjust the position of the linear gradient light transmitting sheet 52 by turning the turntable 583 from the outside of the device.

[0055] A display panel 6 is fixedly provided on the top of the device housing 1. The display panel 6 is used to connect to the photodetector 51 and display the data of light collected by the photodetector 51. In addition, the display panel 6 and the photodetector 51 are both provided with matching power supplies.

[0056] When using a small-sized near-infrared spectrometer with high coupling efficiency according to this embodiment, a sample box 41 is inserted into the sample chamber 4, and the storage boxes of the sample to be analyzed and the comparison sample are respectively connected to the two liquid inlets 427. The two solenoid valves 428 are controlled to open and close alternately. When the solenoid valves 428 are opened, the sample to be analyzed and the comparison sample alternately enter the conduit 426. The peristaltic pump 425 alternately extracts the sample to be analyzed and the comparison sample, so that the sample to be analyzed and the comparison sample alternately enter the cavity 422, and the sample in the cavity 422 enters the capillary 423.

[0057] The light source lamp 22 is controlled to light up, and the light source lamp 22 is turned off. The light emitted by the light source lamp 22 irradiates the inner wall of the light guide cover 23 and the focusing cup 24, and is reflected multiple times in the light guide cover 23 and the focusing cup 24. The reflected light illuminates the light-guiding glass beads 25, so that the light-guiding glass beads 25 form a luminous sphere. After the light-guiding glass beads 25 are illuminated, the light is dispersed into the light guide tube 31. The dispersed light is guided by the light guide lens 32 in the light guide tube 31 and distributed in parallel. The parallel distributed light passes through the sample in the capillary tube 423 in the sample box 41. After passing through the sample, the light enters the light receiving chamber 5. At this time, the parallel light passes through the linear gradient transparent sheet 52 and is then collected by the photodetector 51. The photodetector 51 analyzes the wavelength of the light and compares the wavelength of the light passing through the sample to be analyzed with the comparison sample to achieve analysis of the liquid sample.

[0058] When analyzing different liquid samples, the user turns the turntable 583 through the through slot 584, and the turntable 583 drives the driving gear 582 to rotate, and the driving gear 582 drives the transmission gear 581 to rotate, and the transmission gear 581 drives the threaded rod 58 to rotate, and the threaded rod 58 drives the movable seat 55 to slide through the threaded groove 551, and the movable seat 55 drives the slide 54 to slide, and the slide 54 drives the linear gradient light-transmitting sheet 52 to slide, so that the position of the linear gradient light-transmitting sheet 52 is adjusted. At this time, the wavelength of the light passing through the linear gradient light-transmitting sheet 52 changes. Correspondingly, the photodetector 51 receives light of different wavelengths. According to the transmittance of light of different wavelengths to different samples, the position of the linear gradient light-transmitting sheet 52 is adjusted, so that the photodetector 51 obtains more accurate light wavelength data, thereby ensuring the detection accuracy of the sample.

[0059] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A small near-infrared spectrometer with high coupling efficiency, characterized in that: include: A device housing (1) is provided with a light source chamber (2), a light guide chamber (3), a sample chamber (4) and a light receiving chamber (5) inside the device housing (1), wherein the light source chamber (2) is provided in the middle of the inner side of the device housing (1), and the light guide chamber (3), the sample chamber (4) and the light receiving chamber (5) are each provided with two groups, and the two groups of the light guide chamber (3), the sample chamber (4) and the light receiving chamber (5) are respectively provided horizontally on both sides of the light source chamber (2) and are symmetrically distributed; A fixed cover (21) is fixedly provided in the middle of the outer wall of the light source chamber (2), and a light source lamp (22) is detachably plugged into the interior of the fixed cover (21); A light guide cover (23) is fixedly provided inside the light source chamber (2), the light guide cover (23) is configured as an annular structure, and a socket adapted to the light source lamp (22) is provided through the middle of the outer wall of the light guide cover (23), and light focusing cups (24) are fixedly provided on both sides of the light guide cover (23), the light focusing cups (24) are configured as trumpet-shaped structures, and the inner side surfaces of the light focusing cups (24) and the light guide cover (23) are both provided with a reflective coating, and light guide glass beads (25) are fixedly provided at the ends of the two light focusing cups (24) that are away from each other, and one side of the two light guide glass beads (25) respectively extends to the interior of the two light guide chambers (3). A light guide tube (31) is fixedly provided inside the light guide chamber (3), and both ends of the light guide tube (31) are respectively connected to the light source chamber (2) and the sample chamber (4). A light guide lens (32) is fixedly provided inside the light guide tube (31), and the light guide lens (32) is configured as a convex lens. A sample box (41) is provided in the sample chamber (4); A photoelectric detector (51) and a linear gradient light-transmitting sheet (52) are provided inside the light-receiving chamber (5), wherein the photoelectric detector (51) is fixedly provided on an inner wall of the light-receiving chamber (5) away from the sample chamber (4), and the linear gradient light-transmitting sheet (52) is slidably provided inside the light-receiving chamber (5); A display panel (6) is fixedly provided on the top of the device housing (1).

2. A small-sized near-infrared spectrometer with high coupling efficiency according to claim 1, characterized in that: Also includes: One end of the fixed cover (21) is detachably plugged with a pressure seat (26), one end of the pressure seat (26) is rotatably provided with a mounting seat (27) via a bearing, and the mounting seat (27) is threadedly provided on one end of the fixed cover (21).

3. A small near-infrared spectrometer with high coupling efficiency according to claim 1, characterized in that: Also includes: A fixed sleeve (53) is fixedly provided inside the light receiving chamber (5), a slide seat (54) is rotatably provided inside the fixed sleeve (53), and the linear gradient light-transmitting sheet (52) is fixedly provided in the middle of the slide seat (54).

4. A small-sized near-infrared spectrometer with high coupling efficiency according to claim 3, characterized in that: Also includes: Both sides of the slide seat (54) are fixed with movable seats (55), both sides of the fixed sleeve (53) are penetrated by strip-shaped structure slide grooves (56), the two movable seats (55) are respectively slidably arranged inside the two slide grooves (56), the notches of the two slide grooves (56) are fixed with sealing covers (57), and the two movable seats (55) are respectively arranged inside the two sealing covers (57).

5. The small near-infrared spectrometer with high coupling efficiency according to claim 4, characterized in that: Also includes: The interiors of the two sealing covers (57) are rotatably provided with threaded rods (58) via bearings, the middle portions of the two movable seats (55) are penetrated by threaded grooves (551), and the two threaded rods (58) are respectively threadedly provided inside the two threaded grooves (551).

6. The small near-infrared spectrometer with high coupling efficiency according to claim 5, characterized in that: Also includes: One end of each of the two threaded rods (58) is fixedly provided with a transmission gear (581); one end of the outer wall of the fixed sleeve (53) is rotatably provided with a driving gear (582) through a bearing, and the driving gear (582) is meshed with the transmission gear (581); a turntable (583) is fixedly provided on the inner side of the driving gear (582), and a plurality of anti-slip grooves are provided around the outer wall of the turntable (583); a through groove (584) is provided through the outer side surface of the light receiving chamber (5), and the position of the through groove (584) corresponds to that of the turntable (583).

7. The small near-infrared spectrometer with high coupling efficiency according to claim 1, characterized in that: Also includes: Light-transmitting plates (42) are provided on both sides of the sample box (41), and the positions of the light-transmitting plates (42) coincide with the light guide tube (31).

8. The small near-infrared spectrometer with high coupling efficiency according to claim 1, characterized in that: Also includes: An end plate (44) is fixedly provided at one end of the sample box (41), and the end plate (44) is connected to the outer wall of the device housing (1) by magnetic attraction.

9. The small-sized near-infrared spectrometer with high coupling efficiency according to claim 8, characterized in that: Also includes: A liquid guide cover (421) is fixedly provided inside the sample box (41), and the liquid guide cover (421) is provided between two light-transmitting plates (42). Both ends of the liquid guide cover (421) are provided with cavities (422). A plurality of capillaries (423) are provided between the two cavities (422). A liquid inlet pipe (424) is fixedly provided at the top of the upper cavity (422). A peristaltic pump (425) is fixedly provided at one end of the liquid inlet pipe (424). The peristaltic pump (425) is provided at the top of the upper cavity (422). 5), a conduit (426) is fixedly provided at one end thereof, two liquid inlets (427) are fixedly provided at one end of the conduit (426), and the two liquid inlets (427) are respectively provided on the outer wall of the sample box (41), a solenoid valve (428) is fixedly provided between the two liquid inlets (427) and the conduit (426), a liquid discharge pipe (429) is fixedly provided at the bottom end of the cavity (422) located below, and one end of the liquid discharge pipe (429) is provided on the outer wall of the sample box (41).

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