Laser Raman gas concentration detection device and method based on integrating sphere gas chamber

Abstract

The invention discloses a laser Raman gas concentration detection device and method based on an integrating sphere gas chamber in the field of gas concentration detection.The laser Raman gas concentration detection device comprises an integrating sphere, the outer arc face of the integrating sphere is connected with a butt joint in a penetrating mode, the outer end face of the butt joint is connected with an output joint, and the communication direction of a one-way gas outlet valve faces the exterior of the outer arc face of the integrating sphere; the outer arc surface of the integrating sphere is connected with an air inlet component, the outer arc surface of the integrating sphere is connected with a scattering component, and the other end of the scattering component is connected with a focusing component. The optical fiber coupling technology is utilized to combine scattered light signals in different directions, the collection efficiency of the scattered light signals and the emphasis of gas Raman spectrum signals are remarkably improved, the structure is simple, the operability is high, and compared with a conventional Raman spectrum measurement method, the device has higher accuracy, sensitivity and practicability.

Description

Technical Field

[0001] The present invention relates to the technical field of gas concentration detection, and in particular to a laser Raman gas concentration detection device and method based on an integrating sphere gas chamber. Background Art

[0002] As a key technology in the field of modern science and technology, gas composition analysis and concentration detection play an important role in environmental protection, industrial safety, energy management and scientific research. In the field of environmental protection, by accurately measuring gas composition, harmful substances can be monitored in real time, while greenhouse gas emissions can be controlled to promote air quality improvement. In industrial production, real-time monitoring of gas concentration can help prevent toxic or flammable gas leakage accidents, thereby ensuring production safety and reducing safety hazards. For natural gas and other energy management, gas composition and concentration detection can optimize fuel utilization, reduce waste, and improve energy efficiency. In scientific research, by detecting and analyzing gas data, the laws and mechanisms of natural phenomena can be revealed, promoting the advancement of science and technology.

[0003] There are many spectral technologies commonly used for gas composition and concentration detection. Raman spectroscopy is a technology that analyzes gas composition and inverts concentration based on molecular vibration information. By detecting the inelastic scattering signal of molecules and lasers, the characteristic frequency information about gas molecules is obtained, thereby realizing qualitative and quantitative analysis of gases. The advantages of Raman spectroscopy technology are multi-component analysis, rapid response and wide application range. It has broad application potential in environmental monitoring, industrial process control and scientific research. There are many commonly used gas Raman spectroscopy technologies. Conventional Raman spectroscopy devices are simple, easy to adjust, and highly stable. They are suitable for gas analysis and detection in many fields. However, the excitation and collection efficiency of conventional Raman spectroscopy is limited, resulting in weak Raman scattering signals and difficulty in detecting trace gases. Improving the collection efficiency on the basis of conventional Raman spectroscopy can further improve the detection sensitivity and accuracy while retaining the technical advantages, thereby expanding the application range of conventional Raman spectroscopy.

[0004] The Chinese patent with the announcement number CN107831142B discloses a light scattering confocal excitation collection system, which includes: 2N optical reflectors, the 2N optical reflectors have the same focus, and the divergent light from the focus can be reflected by the remaining optical reflectors in sequence after being reflected by the first optical reflector, and pass through the focus at least once. The light scattering confocal excitation collection system of the present invention can repeatedly reflect the excitation light source through a plurality of optical devices and even focus it on the focus, thereby increasing the utilization efficiency of the excitation light source, and can also efficiently collect the light scattering signal emitted from the focus to the three-dimensional space.

[0005] However, the above-mentioned publicly available solutions have the following shortcomings: At present, the laser Raman gas concentration measurement methods mainly include conventional Raman spectroscopy, cavity-enhanced Raman spectroscopy, fiber-enhanced Raman spectroscopy, and surface-enhanced Raman spectroscopy. Conventional Raman spectroscopy uses laser to directly irradiate the sample, which is simple to operate and can be applied to gas composition analysis, chemical reaction monitoring, environmental monitoring, etc. Cavity-enhanced Raman spectroscopy significantly improves the detection sensitivity by repeatedly reflecting the laser in the optical cavity, and is suitable for detecting low-concentration gas components. Fiber-enhanced Raman spectroscopy can achieve remote measurement by combining with optical fiber sensors, and is suitable for difficult-to-reach environments. Surface-enhanced Raman spectroscopy uses metal nanoparticles and other enhanced substrates to improve the Raman scattering signal of molecules. It has high sensitivity and is suitable for the detection of extremely low concentration gases. Although various Raman spectra have unique advantages, there is still a lack of Raman spectroscopy measurement methods with simple equipment and high sensitivity.

[0006] Although the several commonly used laser Raman gas concentration measurement methods are applicable to different scenarios, they all have certain limitations. Conventional Raman spectroscopy devices are simple and usually only collect scattered light in a single direction. They have limited sensitivity and are difficult to detect low-concentration gases. Cavity-enhanced Raman spectroscopy increases signal intensity by increasing the length of the optical path, but its optical path structure is complex and the laser energy at the focal position is high, which poses a safety hazard for flammable and explosive gases. Fiber-enhanced Raman spectroscopy is convenient for remote measurement, but long-distance fiber transmission may cause signal loss. Surface-enhanced Raman spectroscopy has high sensitivity, but the experimental conditions are complex and the sample requirements are high. Summary of the invention

[0007] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of the present invention to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0008] The purpose of the present invention is to address the technical problems existing in the background technology. The present invention proposes a laser Raman gas concentration detection device and method based on an integrating sphere air chamber. The present invention adopts a high-reflectivity integrating sphere air chamber to collect scattered light signals from three different mutually orthogonal directions, and uses optical fiber coupling technology to combine scattered light signals from different directions, which significantly improves the collection efficiency of scattered light signals and the emphasis of gas Raman spectrum signals. The present invention has a simple structure and strong operability. Compared with conventional Raman spectrum measurement methods, it has higher accuracy, sensitivity and practicality.

[0009] The present invention proposes a laser Raman gas concentration detection device based on an integrating sphere air chamber, comprising an integrating sphere, wherein the outer arc surface of the integrating sphere is penetrated and connected with a butt joint, the outer end surface of the butt joint is installed and connected with an output joint, one end of the output joint is connected with a light output port, the outer arc surface of the integrating sphere is penetrated and connected with a one-way air outlet valve, the communication direction of the one-way air outlet valve is toward the outside of the outer arc surface of the integrating sphere, the outer arc surface of the integrating sphere is connected with an air intake component, the outer arc surface of the integrating sphere is connected with a scattering component, and the other end of the scattering component is connected with a focusing component.

[0010] By adopting the above-mentioned technical scheme, this scheme can realize the effect of video acquisition of the change phenomenon of gas after being irradiated by light through the structure of the output joint. The structure of the docking joint can ensure the sealing of the integrating sphere while ensuring the real-time state inside the integrating sphere through video acquisition.

[0011] Preferably, the scattering component comprises a connecting tube penetrating and connected to the outer arc surface of the integrating sphere, a rotating shaft penetrates and rotatably connected to the side surface of the connecting tube, a rotating handle is connected to one end of the rotating shaft, and a pointer is connected to the other end of the rotating shaft.

[0012] By adopting the above technical solution, the present invention can achieve the effect of adjusting the scattering effect of the device through the combination of the rotating shaft and the rotating handle.

[0013] Preferably, the outer arc surface of the connecting tube is connected to a dial, the rotating shaft passes through the center of the dial, the pointer points in the direction of the dial, the outer arc surface of the rotating shaft is connected to a prism, the prism is arranged inside the connecting tube, the prism is located at the center of the connecting tube, and the prism is triangular.

[0014] By adopting the above technical solution, the present solution can facilitate accurate control of the tilt angle when performing rotation and tilt adjustment through the combination of the dial and the pointer, and at the same time, the combination of the dial and the pointer can facilitate the staff to read.

[0015] Preferably, the focusing component includes a sliding tube connected to one end of the connecting tube away from the integrating sphere, a sliding groove is provided on the side of the sliding tube, a control rod is slidably connected to the inner wall of the sliding groove, and symmetrical blocking plates are connected on both sides of the control rod, and the width of the blocking plates is greater than the width of the sliding groove.

[0016] By adopting the above technical solution, the present solution can effectively improve the sliding adjustment accuracy of the present device through the combination of the sliding groove and the control rod, and the structure of the blocking plate can prevent the external light source from entering the interior of the present device through the sliding groove.

[0017] Preferably, the control rod is connected to a sliding concave lens, a fixed convex lens is connected to a side of the sliding tube close to the connecting tube, and a limiting groove is provided at one end of the sliding tube away from the connecting tube.

[0018] By adopting the above technical solution, the present solution can achieve the zoom effect of the light source of the device through the structure of the sliding concave lens, so that the light intensity of the light source inside the integrating sphere can be adjusted by adjusting the focus position.

[0019] Preferably, the limiting groove is L-shaped, the inner wall of the sliding tube is rotatably connected to a light source, the light source faces the prism, the outer arc surface of the light source is connected to a limiting member, and the limiting member is slidably connected to the inner wall of the limiting groove.

[0020] By adopting the above technical solution, the present solution can quickly and stably lock the light source through the structure of the L-shaped limiting groove, so that when the present device is used, there will be no errors in the detection results due to accidental shaking of the light source.

[0021] A laser Raman gas concentration detection method based on an integrating sphere gas chamber comprises the following steps: S1 is a step of installing the light source. In this step, the light source is inserted into the sliding tube to achieve installation and fixation of the light source. When the light source is inserted, the limiting member is aligned with the limiting groove. When the limiting member is inserted to the bottom of the limiting groove, the light source is rotated to enable the limiting member to slide horizontally inside the limiting groove, thereby achieving a locking effect of the light source. S2 is a step of adding the gas to be detected. In this step, the external gas sample to be detected is connected to the device through a combination of a docking ring and a docking tube. After the docking is completed, the control valve is opened. When the pressure of the external gas to be detected is greater than the atmospheric pressure, the gas to be detected automatically enters the internal space of the integrating sphere. At this time, the excess air inside the integrating sphere is discharged from the one-way air outlet valve to ensure the balance of the air pressure inside the integrating sphere. After a period of gas input, the control valve is closed; S3 is a scattering adjustment step, in which the handle is turned to drive the rotating shaft to rotate, thereby driving the prism to rotate at an inclination angle, so as to change the angle when the light source is irradiated to the surface of the prism, so as to achieve a scattering effect on the light source. The scattered light source can be refracted to the inner arc surface of the integrating sphere, and then reciprocatedly reflected inside the integrating sphere through spherical reflection to form a light source matrix; S4 is a step of adjusting the focus. In this step, the distance between the fixed convex lens and the sliding concave lens can be adjusted by sliding the control rod structure, thereby changing the focus position of the light source. When the focus is exactly on the prism surface, the light intensity inside the integrating sphere is the highest. When the light source is out of focus by the control rod, the light intensity inside the integrating sphere decreases. S5 is a gas detection step, in which the output connector structure is used to collect video information of the Tyndall reaction of the gas sample irradiated with light under the light environment, and then the specific composition of the current gas sample is analyzed.

[0022] In the step of adjusting the focus, the length of the blocking plates on both sides of the control rod is greater than the length of the sliding groove on the side of the sliding tube. When the control rod is slidably adjusted, the blocking plates can always block the opening position of the sliding groove, thereby ensuring the sealing effect inside the sliding tube and avoiding the external light source environment from affecting the detection results inside the sliding tube.

[0023] In summary, the present invention includes at least one of the following beneficial effects: In the present invention, the integrating sphere air chamber has high corrosion resistance and high strength, and multiple gas components can be detected synchronously, and pressurized measurement can be performed. The gas pressure in the integrating sphere air chamber is increased by an external pressurization system, thereby further improving the Raman scattering signal intensity. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0025] Figure 1 It is a front view of an embodiment of a laser Raman gas concentration detection device and method based on an integrating sphere gas chamber of the present invention; Figure 2 It is a schematic diagram of the structure of the sliding tube in an embodiment of the present invention; Figure 3 for Figure 1 A cross-sectional view of Figure 4 A three-way orthogonal light receiving scheme diagram in a laser Raman gas concentration detection device and method based on an integrating sphere gas chamber; Figure markings: 1. integrating sphere; 2. docking joint; 3. output joint; 4. light output port; 5. one-way air outlet valve; 6. air inlet component; 601. docking ring; 602. docking tube; 603. control valve; 7. scattering component; 701. connecting tube; 702. rotating shaft; 703. turning handle; 704. pointer; 705. dial; 706. prism; 8. focusing component; 801. sliding tube; 802. scale line; 803. control rod; 804. blocking plate; 805. limiting groove; 806. fixed convex lens; 807. sliding concave lens; 808. light source; 809. limiting member. DETAILED DESCRIPTION

[0026] The following is combined with Figure 1-4 The present invention is described in further detail.

[0027] Embodiment 1, as Figure 1-Figure 4 As shown, in order to solve the existing problems, the present invention discloses a laser Raman gas concentration detection device based on an integrating sphere air chamber in this embodiment, including an integrating sphere 1, wherein the outer arc surface of the integrating sphere 1 is penetrated by a docking joint 2, the outer end surface of the docking joint 2 is installed with an output joint 3, one end of the output joint 3 is connected to a light output port 4, the outer arc surface of the integrating sphere 1 is penetrated by a one-way air outlet valve 5, the communication direction of the one-way air outlet valve 5 is toward the outside of the outer arc surface of the integrating sphere 1, the outer arc surface of the integrating sphere 1 is connected to an air intake component 6, the outer arc surface of the integrating sphere 1 is connected to a scattering component 7, and the other end of the scattering component 7 is connected to a focusing component 8.

[0028] The scattering component 7 includes a connecting tube 701 penetrating and connected to the outer arc surface of the integrating sphere 1 , a rotating shaft 702 penetrating and rotatably connected to the side of the connecting tube 701 , a rotating handle 703 connected to one end of the rotating shaft 702 , and a pointer 704 connected to the other end of the rotating shaft 702 .

[0029] The outer arc surface of the connecting tube 701 is connected to a dial 705, the rotating shaft 702 passes through the center of the dial 705, the pointer 704 points to the direction of the dial 705, the outer arc surface of the rotating shaft 702 is connected to a prism 706, the prism 706 is arranged inside the connecting tube 701, and the prism 706 is located at the center of the connecting tube 701, and the prism 706 is triangular.

[0030] The focusing component 8 includes a sliding tube 801 connected to the end of the connecting tube 701 away from the integrating sphere 1, a sliding groove is provided on the side of the sliding tube 801, a control rod 803 is slidably connected to the inner wall of the sliding groove, and symmetrical blocking plates 804 are connected on both sides of the control rod 803, and the width of the blocking plates 804 is greater than the width of the sliding groove.

[0031] The control rod 803 is connected to a sliding concave lens 807 , a fixed convex lens 806 is connected to a side of the sliding tube 801 close to the connecting tube 701 , and a limiting groove 805 is provided at one end of the sliding tube 801 away from the connecting tube 701 .

[0032] The limiting groove 805 is L-shaped, and the inner wall of the sliding tube 801 is rotatably connected with a light source 808, the light source 808 faces the prism 706, and the outer arc surface of the light source 808 is connected to a limiting member 809, and the limiting member 809 is slidably connected to the inner wall of the limiting groove 805.

[0033] Embodiment 2, as Figure 1-Figure 4 As shown, in order to solve the existing problems in this embodiment, based on the same concept as the above-mentioned embodiment 1, the laser Raman gas concentration detection method based on the integrating sphere gas chamber includes the following steps: S1 is a step of installing the light source 808. In this step, the light source 808 is inserted into the sliding tube 801 to thereby install and fix the light source 808. When the light source 808 is inserted, the limiting member 809 is aligned with the limiting groove 805. When the limiting member 809 is inserted to the bottom of the limiting groove 805, the light source 808 is rotated so that the limiting member 809 can slide horizontally inside the limiting groove 805, thereby achieving a locking effect of the light source 808. S2 is a step of adding the gas to be detected. In this step, the external gas sample to be detected is connected to the device through the combination of the docking ring 601 and the docking tube 602. After the docking is completed, the control valve 603 is opened. When the pressure of the external gas to be detected is greater than the atmospheric pressure, the gas to be detected automatically enters the internal space of the integrating sphere 1. At this time, the excess air inside the integrating sphere 1 is discharged from the one-way air outlet valve 5, ensuring the balance of the air pressure inside the integrating sphere 1. After a period of gas input, the control valve 603 is closed; S3 is a scattering adjustment step, in which the handle 703 is rotated to drive the rotating shaft 702 to rotate, thereby driving the prism 706 to rotate at an inclined angle, so as to change the angle when the light source irradiates the surface of the prism 706, so as to achieve a scattering effect on the light source. The scattered light source can be refracted to the inner arc surface of the integrating sphere 1, and then reciprocatedly reflected inside the integrating sphere 1 through spherical reflection to form a light source matrix; S4 is a step of adjusting the focus. In this step, the distance between the fixed convex lens 806 and the sliding concave lens 807 can be adjusted by sliding the control rod 803 structure, thereby changing the focus position of the light source 808. When the focus is exactly located on the surface of the prism 706, the light intensity inside the integrating sphere 1 is the highest. When the light source 808 is out of focus by the control rod 803, the light intensity inside the integrating sphere 1 decreases. S5 is a gas detection step, in which the output connector 3 structure collects video information of the Tyndall reaction of the gas sample irradiated with light under the light environment, and then analyzes and obtains the specific composition of the current gas sample.

[0034] In the step of adjusting the focus, the length of the blocking plates 804 on both sides of the control rod 803 is greater than the length of the sliding groove on the side of the sliding tube 801. When the control rod 803 is slidingly adjusted, the blocking plates 804 can always block the opening position of the sliding groove, thereby ensuring the sealing effect inside the sliding tube 801 and avoiding the external light source environment from affecting the detection result inside the sliding tube 801.

[0035] The above are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

[0036] Embodiment three, as Figure 1-Figure 4 As shown, in order to solve the existing problems in this embodiment, based on the same concept as the above-mentioned embodiment 1, the laser Raman gas concentration detection method based on the integrating sphere gas chamber also includes the following operation method: The wavelength of the excitation light source used is 532 nm, and the output light is focused. The integrating sphere air chamber is a standard sphere, hollow inside, with an inner diameter of 25 mm. The inner surface of the integrating sphere air chamber is gold-plated to increase the reflectivity of scattered light. Holes are opened on the surface of the integrating sphere air chamber along the three coordinate axes of X, Y, and Z, with an aperture of 8 mm for transmitting scattered light. The surface of the integrating sphere air chamber is reserved with an air inlet, an exhaust port, and an interface for connecting a barometer, which can be used for gas sealing and pressurized measurements; The first collecting lens, the second collecting lens and the third collecting lens are all convex lenses with a focal length of 13 mm, which are respectively fixed to the outside of the openings in the directions of the three coordinate axes of X, Y and Z, and are sealed and connected to the openings with fluororubber to ensure the airtightness of the integrating sphere air chamber; Long-pass filters, coupling lenses and optical fiber input ports are arranged on the outside of the three collection lenses in order to realize the transmission of spatial scattered light to the optical fiber. On this basis, the scattered light signals collected by the three optical fiber input ports are combined using an optical fiber coupler to obtain enhanced Raman scattered light; The specific steps are: Step 1: Run the 532 nm laser and adjust the position of the fiber output port and the integrating sphere air chamber so that the laser emitted from the fiber output port is focused on the center of the integrating sphere air chamber; Step 2: Fill the gas to be tested into the integrating sphere chamber, and adjust the collecting lens, long-pass filter and coupling lens in the directions of the three coordinate axes of X, Y and Z respectively, so that the collecting lens, long-pass filter and coupling lens in each direction are arranged coaxially; Step 3: Adjust the positions of the fiber input ports in the directions of the three coordinate axes X, Y, and Z respectively, so that the fiber input port is located at the focal position of the coupling lens. At the same time, by observing the real-time Raman scattering signal of the sample gas collected by the spectrometer, adjust the angle of the fiber input port so that the Raman characteristic peaks in the directions of the three coordinate axes X, Y, and Z all reach the maximum value; Step 4: Use a three-channel fiber coupler to combine the scattered signals collected from the fiber input ports in the three coordinate axis directions of X, Y, and Z, and transmit the combined light to the spectrometer; Step 5: The spectrometer is connected to a computer, which processes and analyzes the signals collected by the spectrometer, identifies the components of various gases and calculates their concentrations through a concentration calculation model.

[0037] Embodiment 4, as Figure 1-Figure 4As shown, in order to solve the existing problems, based on the same concept as the above-mentioned embodiment 1, the laser Raman gas concentration detection method based on the integrating sphere gas chamber also includes an improved solution using three-way orthogonal light reception, including the following steps: The outer arc surface of the integrating sphere 1 is penetrated by three groups of output connectors 3, which are perpendicularly distributed on the side of the outer arc surface of the integrating sphere 1. One end of the outer end surface of the output connector 3 is provided with a light output port 4, and the three groups of output connectors 3 are all facing the center of the integrating sphere 1. The device also includes external supporting equipment used in conjunction with the device, and the supporting equipment includes but is not limited to a spectrometer and a computer. The spectrometer is communicatively connected to the three groups of light output ports 4 in the present solution, and the spectrometer is communicatively connected to the computer. The light output results in three directions are analyzed by the spectrometer, and the results are finally displayed on the computer screen, thereby reducing the difficulty of optical signal processing for the staff.

Claims

1. A laser Raman gas concentration detection device based on an integrating sphere gas chamber, comprising an integrating sphere (1), characterized in that: The outer arc surface of the integrating sphere (1) is connected through a butt joint (2), the outer end surface of the butt joint (2) is connected to an output joint (3), one end of the output joint (3) is connected to a light output port (4), the outer arc surface of the integrating sphere (1) is connected through a one-way air outlet valve (5), the communication direction of the one-way air outlet valve (5) is toward the outside of the outer arc surface of the integrating sphere (1), the outer arc surface of the integrating sphere (1) is connected to an air intake component (6), the outer arc surface of the integrating sphere (1) is connected to a scattering component (7), and the other end of the scattering component (7) is connected to a focusing component (8).

2. The laser Raman gas concentration detection device based on an integrating sphere gas chamber according to claim 1, characterized in that: The scattering component (7) comprises a connecting tube (701) penetrating and connected to the outer arc surface of the integrating sphere (1); a rotating shaft (702) penetrating and rotatably connected to the side surface of the connecting tube (701); a rotating handle (703) being connected to one end of the rotating shaft (702); and a pointer (704) being connected to the other end of the rotating shaft (702).

3. The laser Raman gas concentration detection device based on an integrating sphere gas chamber according to claim 2, characterized in that: The outer arc surface of the connecting tube (701) is connected to a dial (705), the rotating shaft (702) passes through the center of the dial (705), the pointer (704) faces the direction of the dial (705), the outer arc surface of the rotating shaft (702) is connected to a prism (706), the prism (706) is arranged inside the connecting tube (701), the prism (706) is located at the center of the connecting tube (701), and the prism (706) is triangular.

4. The laser Raman gas concentration detection device based on an integrating sphere gas chamber according to claim 3 is characterized in that: The focusing component (8) comprises a sliding tube (801) connected to an end of the connecting tube (701) away from the integrating sphere (1); a sliding groove is provided on a side of the sliding tube (801); a control rod (803) is slidably connected to the inner wall of the sliding groove; symmetrical blocking plates (804) are connected to both sides of the control rod (803); and the width of the blocking plates (804) is greater than the width of the sliding groove.

5. The laser Raman gas concentration detection device based on an integrating sphere gas chamber according to claim 4, characterized in that: The control rod (803) is connected to a sliding concave lens (807), a fixed convex lens (806) is connected to a side of the sliding tube (801) close to the connecting tube (701), and a limiting groove (805) is provided at one end of the sliding tube (801) away from the connecting tube (701).

6. The laser Raman gas concentration detection device based on an integrating sphere gas chamber according to claim 5, characterized in that: The limiting groove (805) is L-shaped, and the inner wall of the sliding tube (801) is rotatably connected to a light source (808), the light source (808) faces the prism (706), the outer arc surface of the light source (808) is connected to a limiting member (809), and the limiting member (809) is slidably connected to the inner wall of the limiting groove (805).

7. A laser Raman gas concentration detection method based on an integrating sphere gas chamber, comprising the following steps: S1: a step of installing the light source (808), in which the light source (808) is inserted into the interior of the sliding tube (801), thereby installing and fixing the light source (808). When the light source (808) is inserted, the limiting member (809) is aligned with the limiting groove (805). When the limiting member (809) is inserted to the bottom of the limiting groove (805), the light source (808) is rotated to enable the limiting member (809) to slide horizontally inside the limiting groove (805), thereby achieving a locking effect of the light source (808); S2 is a step of adding the gas to be detected. In this step, the external gas sample to be detected is connected to the device through the combination of the docking ring (601) and the docking tube (602). After the docking is completed, the control valve (603) is opened. When the pressure of the external gas to be detected is greater than the atmospheric pressure, the gas to be detected automatically enters the internal space of the integrating sphere (1). At this time, the excess air inside the integrating sphere (1) is discharged from the one-way air outlet valve (5), ensuring the balance of the air pressure inside the integrating sphere (1). After a period of gas input, the control valve (603) is closed; S3 is a scattering adjustment step, in which the handle (703) is rotated to drive the rotating shaft (702) to rotate, thereby driving the prism (706) to rotate at an inclined angle, thereby changing the angle when the light source irradiates the surface of the prism (706), thereby achieving a scattering effect on the light source, and the scattered light source can be refracted to the inner arc surface of the integrating sphere (1), and then reciprocatedly reflected inside the integrating sphere (1) through spherical reflection, forming a light source matrix; S4 is a step of adjusting the focus. In this step, the distance between the fixed convex lens (806) and the sliding concave lens (807) can be adjusted by means of a sliding control rod (803), thereby changing the focus position of the light source (808). When the focus is exactly located on the surface of the prism (706), the light intensity inside the integrating sphere (1) is the highest. When the light source (808) is out of focus by means of the control rod (803), the light intensity inside the integrating sphere (1) decreases. S5 is a gas detection step, in which the output connector (3) structure is used to collect video information of the Tyndall reaction of the gas sample irradiated with light under the light environment, and then the specific composition of the current gas sample is analyzed.

8. The laser Raman gas concentration detection method based on an integrating sphere gas chamber according to claim 7, characterized in that: In the step of adjusting the focus, the length of the blocking plates (804) on both sides of the control rod (803) is greater than the length of the sliding groove on the side of the sliding tube (801). When the control rod (803) is slidably adjusted, the blocking plates (804) can always block the opening position of the sliding groove, thereby ensuring the sealing effect inside the sliding tube (801) and preventing the external light source environment from affecting the detection result inside the sliding tube (801).

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