A quartz-free raman signal gas cell device for raman spectroscopy

Abstract

A quartz-free Raman signal gas chamber device for Raman spectrum detection, comprising a first gas chamber, a capillary and a second gas chamber; the first gas chamber comprises a first window sheet and a dichroic mirror; the second gas chamber comprises a second channel and a second window sheet; the second window sheet is far away from the capillary and is in an inclined state; in use, after the laser passes through the first window sheet, it is reflected by the dichroic mirror into the capillary to react with the gas to be detected to generate a Raman signal, then the laser passes through the second channel and the second window sheet, and the Raman signal is reflected by the second window sheet to pass out of the dichroic mirror; the quartz Raman signal generated by the first window sheet passes out of the dichroic mirror, and the quartz Raman signal generated by the second window sheet cannot be captured by the capillary; the second window sheet is in an inclined state, so the capillary cannot generate a quartz Raman signal; the design eliminates the quartz Raman signal from three aspects, making the spectrum result accurate. Therefore, the design will not be affected by the quartz Raman signal when detecting the gas, and the detection accuracy is high.

Description

Technical Field

[0001] This invention relates to a gas chamber device, belonging to the field of gas detection, and particularly to a gas chamber device for Raman spectroscopy detection without quartz Raman signal. Background Technology

[0002] Currently, gas detection has wide applications in various fields, such as environmental gas detection, medical diagnostics, and fuel gas detection; and in industrial environments, gas detection is of great significance for human safety. Therefore, to meet diverse needs, the ability to efficiently and accurately identify and quantify gases in different situations is particularly important. Against this backdrop, Raman spectroscopy plays a crucial role in gas detection.

[0003] In Raman spectroscopy, a gas cell is commonly used as the site for the reaction between the gas and the laser. However, traditional gas cells used in Raman spectroscopy have a problem: the severe quartz Raman signal caused by the window restricts the accuracy of gas component detection, thus reducing the detection precision of the Raman system. Therefore, in existing technologies, gas cell detection of gases is affected by the quartz Raman signal.

[0004] The information disclosed in this background section is intended only to enhance understanding of the overall background of this application and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to overcome the defects and problems of existing technologies where gas detection in gas chambers is affected by quartz Raman signals, and to provide a gas chamber device for Raman spectroscopy detection that is unaffected by quartz Raman signals.

[0006] To achieve the above objectives, the technical solution of the present invention is:

[0007] A gas cell device for Raman spectroscopy detection without quartz Raman signal, the device comprising a first gas cell, a capillary tube and a second gas cell;

[0008] The first air chamber is an isosceles right-angled triangle. The outer surface of the first air chamber includes an incident plane, an exit plane, and a reflecting slope. One end of the incident plane is perpendicularly connected to one end of the exit plane, and the other end of the incident plane is connected to one end of the reflecting slope, which in turn is connected to the exit plane. The interior of the incident plane, exit plane, and reflecting slope forms a first cavity, which includes a laser incident channel, a dichroic mirror, and a laser reflection channel. The laser incident channel includes an inlet end, a connecting end, and an air inlet pipe. The inlet end is located on the incident plane and is equipped with… A first window is provided; the air inlet pipe is located in the middle of the laser incident channel, and one end of the air inlet pipe is vertically connected to the top of the first air chamber; the end of the laser incident channel away from the inlet end is a connecting end, and the connecting end is connected to the middle of one end of the laser reflection channel; the laser reflection channel includes a reflecting end and an emitting end, the reflecting end is connected to one end of a dichroic mirror, the dichroic mirror is located in the middle of the reflecting slope, and the middle of the reflecting end is connected to the connecting end; the emitting end is located on the end of the laser reflection channel away from the reflecting end, and the emitting end passes through the emitting straight surface to reach the outside of the emitting straight surface;

[0009] The ejector end is connected to one end of the capillary tube, which is a hollow tube. The other end of the capillary tube is the left end face, which is connected to the second air chamber.

[0010] The second air chamber includes a second channel, a second window, and a second outlet hole. The second channel includes a second inlet end and a second reflective end. The second inlet end is connected to the left end face. The second reflective end is located at the end of the second channel away from the second inlet end. The second reflective end is connected to one end of the second window. The distance between the second window and the left end face is greater than 10 cm. The second window and the normal of the second channel form an inclined angle greater than 5 degrees. The other end of the second window is connected to the second outlet hole. The second outlet hole is located at the end of the second air chamber away from the second channel. An air outlet channel is also provided in the middle of the second channel. One end of the air outlet channel is connected to the outer surface of the second air chamber.

[0011] The outer side of the ejection end is fitted with a rubber tube, and the outer side of the rubber tube is fitted with a clamp.

[0012] A capillary seal is fitted onto the end of the capillary tube connected to the outlet end. The capillary seal includes a capillary compression member and a spherical washer. The spherical washer is fitted onto the outside of the end of the capillary tube connected to the outlet end. The capillary compression member includes a threaded end and a hollow part. The hollow part is fitted onto the outside of the end of the capillary tube connected to the outlet end. The threaded end is located on the end of the capillary compression member near the connection end. The threaded end and the spherical washer are inserted into one end of the rubber tube and connected to one end of the spherical washer.

[0013] The left end face is fitted with a capillary seal;

[0014] The capillary seal includes a capillary pressure member and a spherical washer. The spherical washer is fitted over the outside of the left end face. The capillary pressure member includes a threaded end and a hollow part. The hollow part is fitted over the outside of the left end face. The threaded end is located on the end of the capillary pressure member near the second inlet end. The threaded end and the spherical washer are inserted into the interior of the second air chamber near the second inlet end. The threaded end is connected to one end of the spherical washer.

[0015] The dichroic mirror is fitted with a dichroic spherical washer, and the dichroic spherical washer is provided with an external thread, which is connected to the middle part of the reflecting slope.

[0016] The diameter of the reflecting end is larger than the diameter of the emitting end, and the diameter of the emitting end is larger than the diameter of the laser incident channel.

[0017] The second inlet end is connected to one end of the second connection end, the other end of the second connection end is connected to one end of the second large end, and the other end of the second large end is connected to one end of the second reflective end;

[0018] The diameter of the second large end is greater than the diameter of the second reflective end, the diameter of the second reflective end is greater than the diameter of the second connecting end, and the diameter of the second connecting end is greater than the diameter of the second inlet end.

[0019] The diameter of the reflecting end is 12 mm, the diameter of the emitting end is 10 mm, and the diameter of the laser incident channel is 8 mm.

[0020] The incident plane has four connecting holes evenly distributed around its perimeter, and the exit plane has four connecting holes evenly distributed around its perimeter.

[0021] The second outlet hole is vertically connected to a cage-type connector, which is a hollow cylinder.

[0022] The inner surface of the air intake pipe is uniformly distributed with threaded structures, and the inner surface of the air outlet channel is uniformly distributed with threaded structures.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] 1. In a gas cell device for Raman spectroscopy detection without quartz Raman signal, the present invention includes a first gas cell, a capillary, and a second gas cell. The first gas cell includes a laser incident channel, a dichroic mirror, and a laser reflection channel. The laser incident channel includes a first window. The second gas cell includes a second channel, a second window, and a second outlet hole. In application, the laser moves along the laser incident channel through the first window, is reflected by the dichroic mirror to the laser reflection channel, and then enters the capillary to react with the gas to be measured to generate a Raman signal. The laser then enters the second channel and exits through the second window. The Raman signal is reflected by the second window, passes through the capillary, and exits through the dichroic mirror. The present invention uses the first window... The first window is positioned at the front of the laser incident channel. Since the quartz Raman signal generated by the first window passes through the dichroic mirror, it has no effect. In the second gas chamber, although a quartz Raman signal is generated when the laser irradiates the second window, it is not captured by the capillary due to the large distance between the second window and the capillary, and therefore is not received by the spectrometer. Furthermore, if the tilt angle of the second window is greater than 5 degrees, the laser will not re-irradiate the inner wall of the capillary, thus preventing the generation of a quartz Raman signal. This invention eliminates the influence of the quartz Raman signal from three aspects, preventing the appearance of quartz peaks in the Raman spectrum. Therefore, it allows for more accurate Raman spectrum comparison, thereby improving the accuracy of gas detection. Thus, this invention is not affected by the quartz Raman signal when detecting gases and achieves high detection accuracy.

[0025] 2. In the gas cell device for Raman spectroscopy detection without quartz Raman signal of the present invention, both ends of the capillary are fitted with capillary seals. During application, the capillary seals prevent air leakage at the connection between the capillary and the first and second gas cells, and also prevent the introduction of external gases. Therefore, the device has good sealing performance and high detection accuracy. Thus, the present invention has good sealing performance.

[0026] 3. In the gas chamber device for Raman spectroscopy detection without quartz Raman signals of the present invention, the diameters of the laser incident channel, the exit end, and the reflection end increase sequentially, as do the diameters of the second inlet end, the second connecting end, the second reflection end, and the second large end. In application, the sequential increase in the diameters of the exit end and the reflection end is to avoid blocking the Raman signal with its gradually increasing diameter, and the sequential increase in the diameters of the second inlet end, the second connecting end, the second reflection end, and the second large end is to avoid blocking the laser with its gradually increasing diameter. Simultaneously, the designed tube diameter reduces the weight of the invention and also helps save installation space, enabling the invention to be used in environments with limited space, such as mobile detection equipment or embedded systems. Therefore, the present invention provides convenience for gas analysis in confined spaces.

[0027] 4. In the gas cell device for Raman spectroscopy detection without quartz Raman signal of the present invention, connecting holes are provided on both the incident and exit surfaces, and a cage-type connector is provided on the second outlet hole. The inlet and outlet pipes are provided with threaded structures. In application, the connecting holes and cage-type connectors are compatible with a 30 mm cage structure, and the threaded structures of the inlet and outlet pipes can communicate with the pipe of the gas to be measured. Therefore, the present invention can be connected to other devices. Thus, the present invention has good connectivity. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of the present invention.

[0029] Figure 2 yes Figure 1 Top view.

[0030] Figure 3 yes Figure 1 A schematic diagram of the structure of the second air chamber.

[0031] Figure 4 yes Figure 1 A schematic diagram of the structure of the first air chamber.

[0032] Figure 5 yes Figure 4 A schematic diagram of the structure of a dichroic mirror.

[0033] Figure 6 yes Figure 4 Cross-sectional view.

[0034] Figure 7 yes Figure 6 Top view.

[0035] Figure 8 yes Figure 1 Cross-sectional view of the first air chamber.

[0036] Figure 9 yes Figure 8 Top view.

[0037] Figure 10 yes Figure 1 A schematic diagram of the structure of a capillary seal.

[0038] Figure 11 yes Figure 10 Cross-sectional view.

[0039] Figure 12 This is a schematic diagram of a traditional air chamber application.

[0040] Figure 13 yes Figure 12 The Raman spectrum.

[0041] Figure 14 yes Figure 1 Application diagram.

[0042] Figure 15 yes Figure 14 The Raman spectrum.

[0043] In the diagram: First gas chamber 1, incident plane 11, exit plane 12, reflecting slope 13, first chamber 14, connecting hole 15, capillary tube 2, left end face 21, second gas chamber 3, second channel 31, second inlet end 311, second reflecting end 312, second connecting end 313, second large end 314, second window 32, inclined angle 34, second outlet hole 35, exhaust channel 36, cage-type connector 37, laser incident channel 4, inlet end 41, connecting end 42, air inlet pipe 43, first window 44, dichroic mirror 5, dichroic spherical washer 51, washer external thread 52 6. Laser reflection channel; 61. Reflection end; 62. Emission end; 63. Rubber tube; 64. Clamp; 7. Capillary seal; 71. Capillary clamp; 71. Threaded end; 711. Hollow part; 712. Spherical washer; 72. Incident laser; 8. Traditional first window; 91. Traditional second window; 92. 200mm focal length lens; 93. Filter; 94. Reflector; 95. Traditional dichroic mirror; 96. 75mm focal length lens; 97. Cut-off plate; 98. 30mm focal length lens; 99. Gas inlet; 100. Gas outlet; 101. Traditional capillary; 102. Raman signal; 103. Quartz Raman signal. Detailed Implementation

[0044] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0045] Please see Figure 1 — Figure 15 A gas cell device for Raman spectroscopy detection without quartz Raman signal, the device comprising a first gas cell 1, a capillary tube 2 and a second gas cell 3;

[0046] The first air chamber 1 is an isosceles right triangle. The outer surface of the first air chamber 1 includes an incident straight surface 11, an exit straight surface 12, and a reflecting inclined surface 13. One end of the incident straight surface 11 is perpendicularly connected to one end of the exit straight surface 12, and the other end of the incident straight surface 11 is connected to one end of the reflecting inclined surface 13. The other end of the reflecting inclined surface 13 is connected to one end of the exit straight surface 12. The interior of the incident straight surface 11, the exit straight surface 12, and the reflecting inclined surface 13 forms a first chamber 14. The first chamber 14 includes a laser incident channel 4, a dichroic mirror 5, and a laser reflection channel 6. The laser incident channel 4 includes an inlet end 41, a connecting end 42, and an air inlet pipe 43. The inlet end 41 is located on the incident straight surface 11. 1. A first window 44 is provided; the air inlet pipe 43 is located in the middle of the laser incident channel 4, and one end of the air inlet pipe 43 is vertically connected to the top of the first air chamber 1; the end of the laser incident channel 4 away from the inlet end 41 is a connecting end 42, and the connecting end 42 is connected to the middle of one end of the laser reflection channel 6; the laser reflection channel 6 includes a reflecting end 61 and an exit end 62, the reflecting end 61 is connected to one end of the dichroic mirror 5, the dichroic mirror 5 is located in the middle of the reflecting inclined surface 13, and the middle of the reflecting end 61 is connected to the connecting end 42; the exit end 62 is located on the end of the laser reflection channel 6 away from the reflecting end 61, and the exit end 62 passes through the exit straight surface 12 to reach the outside of the exit straight surface 12;

[0047] The ejection end 62 is connected to one end of the capillary tube 2, which is a hollow tube. The other end of the capillary tube 2 is the left end face 21, which is connected to the second air chamber 3.

[0048] The second air chamber 3 includes a second channel 31, a second window 32, and a second outlet hole 35. The second channel 31 includes a second inlet end 311 and a second reflective end 312. The second inlet end 311 is connected to the left end face 21. The second reflective end 312 is located at the end of the second channel 31 away from the second inlet end 311. The second reflective end 312 is connected to one end of the second window 32. The distance between the second window 32 and the left end face 21 is greater than 10 cm. An inclined angle 34 is formed between the normal of the second window 32 and the second channel 31. The inclined angle 34 is greater than 5 degrees. The other end of the second window 32 is connected to the second outlet hole 35. The second outlet hole 35 is located at the end of the second air chamber 3 away from the second channel 31. An air outlet channel 36 is also provided in the middle of the second channel 31. One end of the air outlet channel 36 is connected to the outer surface of the second air chamber 3.

[0049] The outer side of the emission end 62 is fitted with a rubber tube 63, and the outer side of the rubber tube 63 is fitted with a clamp 64.

[0050] A capillary seal 7 is fitted onto the end of the capillary tube 2 connected to the outlet end 62. The capillary seal 7 includes a capillary pressure member 71 and a spherical washer 72. The spherical washer 72 is fitted onto the outside of the end of the capillary tube 2 connected to the outlet end 62. The capillary pressure member 71 includes a threaded end 711 and a hollow part 712. The hollow part 712 is fitted onto the outside of the end of the capillary tube 2 connected to the outlet end 62. The threaded end 711 is located on the end of the capillary pressure member 71 near the connecting end 42. The threaded end 711 and the spherical washer 72 are inserted into the inside of one end of the rubber tube 63. The threaded end 711 is connected to one end of the spherical washer 72.

[0051] The left end face 21 is covered with a capillary seal 7.

[0052] The capillary seal 7 includes a capillary clamp 71 and a spherical washer 72. The spherical washer 72 is fitted on the outside of the left end face 21. The capillary clamp 71 includes a threaded end 711 and a hollow part 712. The hollow part 712 is fitted on the outside of the left end face 21. The threaded end 711 is located on the end of the capillary clamp 71 near the second inlet end 311. The threaded end 711 and the spherical washer 72 are inserted into the interior of the second air chamber 3 near the second inlet end 311. The threaded end 711 is connected to one end of the spherical washer 72.

[0053] The dichroic mirror 5 is fitted with a dichroic spherical washer 51, and the dichroic spherical washer 51 is provided with an external thread 52, which is connected to the middle part of the reflecting slope 13.

[0054] The diameter of the reflecting end 61 is larger than the diameter of the emitting end 62, and the diameter of the emitting end 62 is larger than the diameter of the laser incident channel 4.

[0055] The second inlet end 311 is connected to one end of the second connection end 313, the other end of the second connection end 313 is connected to one end of the second large end 314, and the other end of the second large end 314 is connected to one end of the second reflective end 312.

[0056] The diameter of the second large end 314 is greater than the diameter of the second reflective end 312, the diameter of the second reflective end 312 is greater than the diameter of the second connecting end 313, and the diameter of the second connecting end 313 is greater than the diameter of the second inlet end 311.

[0057] The diameter of the reflecting end 61 is 12 mm, the diameter of the emitting end 62 is 10 mm, and the diameter of the laser incident channel 4 is 8 mm.

[0058] The incident straight surface 11 has four connecting holes 15 evenly distributed around its perimeter, and the exit straight surface 12 has four connecting holes 15 evenly distributed around its perimeter.

[0059] The second outlet hole 35 is vertically connected to a cage-type connector 37, which is a hollow cylinder.

[0060] The inner surface of the air intake pipe 43 is uniformly distributed with threaded structures, and the inner surface of the air outlet channel 36 is uniformly distributed with threaded structures.

[0061] The following are supplementary descriptions of the present invention:

[0062] The Raman spectroscopy technology described in this invention refers to a technique for gas detection that measures the interaction of a gas with light of a specific wavelength. Each gas has unique spectral characteristics, making Raman spectroscopy a powerful tool. Raman spectroscopy can be used to detect single gases or multi-component gases, and through Raman spectral analysis, we can obtain crucial information about gas composition, concentration, and temperature. In Raman spectroscopy detection, a laser reacts with the analyte gas within a gas chamber. The design and manufacture of the gas chamber typically consider various factors, including optical path length and optical window material. The function of the gas chamber is to enable effective interaction between the analyte gas and the light, making spectral detection more sensitive and suitable for high-precision gas analysis applications such as combustion process monitoring, gas quality analysis, and environmental gas monitoring. Therefore, the design of the gas chamber is crucial.

[0063] The conventional air chamber described in this invention refers to: Please refer to Figure 12 — Figure 13 , Figure 12This is a schematic diagram of a traditional gas chamber application. The laser is first generated by a laser emitter, then focused by a 200mm focusing lens 92. After passing through a filter 93 to remove stray light, the laser is reflected by a mirror 94 and then reflected again by a traditional dichroic mirror 95. The laser then passes through the traditional first window 9, generating a first quartz Raman signal 103. This first Raman signal 103 is received by a 75mm focal length lens 96 located at the signal focal point and subsequently received by a spectrometer. The gas to be measured enters the traditional capillary 101 through a gas inlet 99. The laser and the gas react within the capillary 101, generating a Raman signal 102. The gas then exits the capillary 101 through a gas outlet 100. The laser and Raman signal 102 continue to the traditional second window 91, and then the laser exits the traditional second window 95. The laser beam exits through a second window 91. As it passes through the conventional second window 91, a second quartz Raman signal 103 is generated, which is captured by a conventional capillary tube 101. The Raman signal 102 and the second quartz Raman signal 103 return from the conventional capillary tube 101. After passing through a conventional dichroic mirror 95, they are parallelized by a 75mm focal length lens 96. The Raman signal 102, the first quartz Raman signal 103, and the second quartz Raman signal 103 are then filtered by a cutoff plate 97 to remove scattered light. After being focused by a 30mm focal length lens 98, they are collected by an optical fiber and enter a spectrometer for analysis. Finally, a Raman spectrum is created in a CCD camera. Please refer to [link to relevant documentation]. Figure 13 The figure shows the Raman spectrum of a traditional gas cell. It can be seen that there is a relatively obvious quartz peak within the black box. This quartz peak overlaps with part of the Raman signal 102, interfering with the display of the Raman signal 102 and affecting the accuracy of gas cell detection.

[0064] Example 1:

[0065] Please see Figure 1 — Figure 15A gas cell device for detecting quartz Raman signals using Raman spectroscopy includes a first gas cell 1, a capillary tube 2, and a second gas cell 3. The first gas cell 1 is an isosceles right triangle, and its outer surface includes an incident plane 11, an exit plane 12, and a reflecting slope 13. One end of the incident plane 11 is perpendicular to one end of the exit plane 12, and the other end of the incident plane 11 is connected to one end of the reflecting slope 13, which is also connected to one end of the exit plane 12. The interior of the incident plane 11, the exit plane 12, and the reflecting slope 13 forms a first chamber 14, which includes a laser incident channel 4 and a dichroic mirror. 5. Laser reflection channel 6; The laser incident channel 4 includes an inlet end 41, a connecting end 42, and an air inlet pipe 43. The inlet end 41 is located on the incident plane 11 and is provided with a first window 44. The air inlet pipe 43 is located in the middle of the laser incident channel 4, and one end of the air inlet pipe 43 is vertically connected to the top of the first gas chamber 1. The end of the laser incident channel 4 away from the inlet end 41 is the connecting end 42, which is connected to the middle of one end of the laser reflection channel 6. The laser reflection channel 6 includes a reflecting end 61 and an exit end 62. The reflecting end 61 is connected to one end of the dichroic mirror 5, and the dichroic mirror 5 is located at the reflecting oblique angle. In the middle of surface 13, the middle of the reflecting end 61 is connected to the connecting end 42; the emitting end 62 is located at the end of the laser reflecting channel 6 away from the reflecting end 61, and the emitting end 62 passes through the emitting straight surface 12 to reach the outside of the emitting straight surface 12; the emitting end 62 is connected to one end of the capillary tube 2, the capillary tube 2 is a hollow tube, and the other end of the capillary tube 2 is the left end face 21, which is connected to the second gas chamber 3; the second gas chamber 3 includes a second channel 31, a second window 32 and a second outlet hole 35, the second channel 31 includes a second inlet end 311 and a second reflecting end 312, the second inlet end 311 is connected to the left end face 21, and the second emitting end 62 is connected to the connecting end 42. The second reflector 312 is located on the end of the second channel 31 away from the second inlet end 311. The second reflector 312 is connected to one end of the second window 32. The distance between the second window 32 and the left end face 21 is greater than 10 cm. The second window 32 and the normal of the second channel 31 form an inclined angle 34, which is greater than 5 degrees. The other end of the second window 32 is connected to the second outlet hole 35. The second outlet hole 35 is located on the end of the second air chamber 3 away from the second channel 31. An air outlet channel 36 is also provided in the middle of the second channel 31. One end of the air outlet channel 36 is connected to the outer surface of the second air chamber 3.

[0066] In application, the incident laser 8 is generated by a laser emitter. The incident laser 8 is first focused by a 200mm focal length lens, then filtered by a filter 93 to remove stray light. After the incident laser 8 passes through a reflector 94 to change direction, it enters the first window 44. The first window 44 ensures the airtightness of the first gas chamber 1, but the reaction between the incident laser 8 and the first window 44 generates a quartz Raman signal 103. The incident laser 8 then enters the inlet end 41 and moves towards the connection end 42. Then, the incident laser 8 enters the reflection end 61 and is reflected by the dichroic mirror 5 towards the outlet end 62. The dichroic mirror 5 itself does not generate a quartz Raman signal 103. Because the wavelength of the quartz Raman signal 103 is relatively long, the dichroic mirror 5 will reflect the light from the first window 44. The generated quartz Raman signal 103 is emitted, therefore it will not be received by the spectrometer. Then, the incident laser 8 moves from the exit end 62 towards the capillary 2. Simultaneously, the gas to be measured enters the laser incident channel 4 through the inlet pipe 43 and then enters the capillary 2. The gas to be measured reacts with the incident laser 8 within the capillary 2 to generate a Raman signal 102. The incident laser 8 and the Raman signal 102 continue to move forward, passing the left end face 21 and entering the second inlet end 311. Then, the incident laser 8 and the Raman signal 102 move towards the second reflection end 312. The incident laser 8 passes through the second window plate 32 and exits. The incident laser 8 reacts with the second window plate 32 to generate a quartz Raman signal 103. Because the second window plate 32 and the left... Because the distance between end face 21 and the target end is greater than 10 cm, the angle at which the left end face 21 receives the quartz Raman signal 103 is reduced. Therefore, the quartz Raman signal 103 will not be captured by the left end face 21, while the Raman signal 102 will be reflected back into the capillary tube 2 by the second window plate 32. Then, the Raman signal 102 passes through the output end 62 and the reflection end 61 in sequence and exits through the dichroic mirror 5. The Raman signal 102 then passes through the 75mm focal length lens 96 and is focused into a parallel state. Then, the Raman signal 102 passes through the cutoff plate 97 and the scattered excitation light is removed by the cutoff plate 97. The Raman signal 102 is then focused by the 30mm focal length lens 98 and collected into the optical fiber. Finally, the Raman signal 102 moves through the optical fiber into the spectrometer. After analysis by the spectrometer, the Raman signal 102 creates a Raman spectrum in the CCD camera. The tilt angle 34 of the second window 32 is greater than 5 degrees, which prevents the incident laser 8 from being reflected by the second window 32 and directly irradiating the inner wall of the capillary 2. When the incident laser 8 irradiates the inner wall of the capillary 2, a quartz Raman signal 103 will be generated, which will cause interference to the detection. The first window 44 makes the first gas chamber 1 more airtight, and the second window 32 makes the second gas chamber 3 more airtight. Both the first window 44 and the second window 32 prevent the incident laser 8 from directly irradiating the metal material inside the device. If the incident laser 8 irradiates the metal material, it will trigger Raman fluorescence, which will reduce the detection accuracy.The dichroic mirror 5 is tilted at an angle of 45 degrees to ensure that the incident laser 8 has an angle of 90 degrees after both incident and refraction, so that the incident laser 8 can pass through the center of the capillary 2 without hitting the wall of the capillary 2; Figure 15 and Figure 13 By comparison, it can be seen that Figure 15 There are no quartz peaks, and the Raman signal 102 is more clearly displayed.

[0067] Example 2:

[0068] The basic content is the same as in Example 1, except that:

[0069] Please see Figure 1 — Figure 11 The outer end of the ejector 62 is fitted with a rubber tube 63, and the outer end of the rubber tube 63 is fitted with a clamp 64. A capillary seal 7 is fitted on the end of the capillary tube 2 connected to the ejector 62. The capillary seal 7 includes a capillary pressure member 71 and a spherical washer 72. The spherical washer 72 is fitted on the outside of the end of the capillary tube 2 connected to the ejector 62. The capillary pressure member 71 includes a threaded end 711 and a hollow part 712. The hollow part 712 is fitted on the outside of the end of the capillary tube 2 connected to the ejector 62. The threaded end 711 is located on the end of the capillary pressure member 71 near the connecting end 42. The threaded end 711 and the spherical washer 72 are inserted into the inside of one end of the rubber tube 63. The threaded end 711 is connected to one end of the spherical washer 72. A capillary seal 7 is fitted over the left end face 21. The capillary seal 7 includes a capillary pressure member 71 and a spherical washer 72. The spherical washer 72 is fitted over the left end face 21. The capillary pressure member 71 includes a threaded end 711 and a hollow portion 712. The hollow portion 712 is fitted over the left end face 21. The threaded end 711 is located on the end of the capillary pressure member 71 near the second inlet end 311. The threaded end 711 and the spherical washer 72 are inserted into the interior of the second air chamber 3 near the second inlet end 311. The threaded end 711 is connected to one end of the spherical washer 72. A dichroic mirror 5 is fitted over the outside of a dichroic spherical washer 51. The dichroic spherical washer 51 has an external thread 52 on its outside. The external thread 52 is connected to the middle of the reflecting slope 13.

[0070] In application, the rubber tube 63 and clamp 64 are fitted over the outside of the ejector end 62, thus ensuring the airtightness of the ejector end 62. The capillary tube 2, at the end furthest from the left end face 21, is fitted with the hollow portion 712 of the capillary tube clamp 71. A spherical washer 72 is placed on the front side of the threaded end 711 near the connecting end 42. When the threaded end 711 is tightened into the connecting end 42, the threaded end 711 compresses the spherical washer 72, which in turn compresses the capillary tube 2, thus achieving a sealing effect. A hollow portion 712 is also fitted over the outside of the left end face 21. At this time, the threaded end 711 and the spherical washer 72 are inserted into the second inlet end 311. When the threaded end 711 is tightened into the second inlet end 311, the threaded end 711 squeezes the spherical washer 72, and the spherical washer 72 squeezes the capillary tube 2, thus achieving a sealing effect. The dichroic mirror 5 is fitted with a dichroic spherical washer 51. The dichroic spherical washer 51 is connected to the middle part of the reflecting slope 13 through the external thread 52 of the washer. The external thread 52 of the washer stabilizes the position of the dichroic mirror 5, and the dichroic spherical washer 51 ensures the airtightness of the connection of the dichroic mirror 5.

[0071] Example 3:

[0072] The basic content is the same as in Example 1, except that:

[0073] Please see Figure 1 — Figure 9 The diameter of the reflecting end 61 is larger than the diameter of the emitting end 62, and the diameter of the emitting end 62 is larger than the diameter of the laser incident channel 4. The second entrance end 311 is connected to one end of the second connecting end 313, the other end of the second connecting end 313 is connected to one end of the second large end 314, and the other end of the second large end 314 is connected to one end of the second reflecting end 312. The diameter of the second large end 314 is larger than the diameter of the second reflecting end 312, the diameter of the second reflecting end 312 is larger than the diameter of the second connecting end 313, and the diameter of the second connecting end 313 is larger than the diameter of the second entrance end 311. The diameter of the reflecting end 61 is 12 mm, the diameter of the emitting end 62 is 10 mm, and the diameter of the laser incident channel 4 is 8 mm.

[0074] In application, after the Raman signal 102 returns through the capillary 2, it first passes through the output end 62 and then the reflection end 61. Because the diameter of the Raman signal 102 increases with the moving distance, the diameter of the output end 62 is larger than that of the reflection end 61 to prevent the Raman signal 102 from hitting the sidewalls of the output end 62 and the reflection end 61. After the incident laser 8 reaches the second entrance end 311, it sequentially passes through the second connecting end 313, the second large end 314, and the second reflection end 312. Again, because the diameter of the incident laser 8 increases with the moving distance, the diameter of the output end 62 is larger than that of the reflection end 61 to prevent the Raman signal 102 from hitting the sidewalls of the output end 62 and the reflection end 61. The diameters of the second inlet end 311, the second connecting end 313, the second reflecting end 312, and the second large end 314 are all different on the inner wall of the second gas chamber 3. If the incident laser 8 hits the inner wall of the second gas chamber 3, it will cause a more severe Raman fluorescence effect, which will reduce the detection accuracy. The different diameters of the second inlet end 311, the second connecting end 313, the second reflecting end 312, and the second large end 314 help to reduce the overall volume of the second gas chamber 3. The different diameters of the reflecting end 61, the exit end 62, and the laser incident channel 4 help to reduce the overall volume of the first gas chamber 1, which facilitates the installation of this device.

[0075] Example 4:

[0076] The basic content is the same as in Example 1, except that:

[0077] Please see Figure 1 — Figure 8 The incident surface 11 has four evenly distributed connecting holes 15 around its perimeter, and the exit surface 12 also has four evenly distributed connecting holes 15 around its perimeter. A cage-type connector 37, which is a hollow cylinder, is vertically connected to the outside of the second outlet hole 35. The inner surface of the air inlet pipe 43 and the inner surface of the air outlet channel 36 both have evenly distributed threaded structures.

[0078] In application, the connecting hole 15 is compatible with the 30 mm cage structure, so the first air chamber 1 can be fixed on the 30 mm cage structure; the cage connector 37 is also compatible with the 30 mm cage structure, so the second air chamber 3 can be fixed on the 30 mm cage structure; the inner surfaces of the air inlet pipe 43 and the air outlet channel 36 are evenly distributed with threaded structures, which can be connected to threaded pagoda mouth or double ferrule fittings, and then connected to the pipe of the gas to be tested through the pagoda mouth or double ferrule fittings to achieve the effect of air inlet and air outlet.

[0079] The above description is only a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. Any equivalent modifications or changes made by those skilled in the art based on the content disclosed in the present invention should be included within the scope of protection set forth in the claims.

Claims

1. A gas cell device for Raman spectroscopy detection without quartz Raman signal, characterized in that: The device includes a first air chamber (1), a capillary tube (2), and a second air chamber (3); The first air chamber (1) is an isosceles right triangle. The outer surface of the first air chamber (1) includes an incident straight surface (11), an exit straight surface (12), and a reflecting inclined surface (13). One end of the incident straight surface (11) is perpendicularly connected to one end of the exit straight surface (12), and the other end of the incident straight surface (11) is connected to one end of the reflecting inclined surface (13). The other end of the reflecting inclined surface (13) is connected to one end of the exit straight surface (12). The interior of the incident straight surface (11), the exit straight surface (12), and the reflecting inclined surface (13) is a first chamber (14). The first chamber (14) includes a laser incident channel (4), a dichroic mirror (5), and a laser reflection channel (6). The laser incident channel (4) includes an inlet end (41), a connecting end (42), and an air inlet pipe (43). The inlet end (41) is located on the incident straight surface (11). 1) A first window (44) is provided; the air inlet pipe (43) is located in the middle of the laser incident channel (4), and one end of the air inlet pipe (43) is vertically connected to the top of the first air chamber (1); the end of the laser incident channel (4) away from the inlet end (41) is a connecting end (42), and the connecting end (42) is connected to the middle of one end of the laser reflection channel (6); the laser reflection channel (6) includes a reflecting end (61) and an exit end (62), the reflecting end (61) is connected to one end of a dichroic mirror (5), the dichroic mirror (5) is located in the middle of the reflecting slope (13), and the middle of the reflecting end (61) is connected to the connecting end (42); the exit end (62) is located on the end of the laser reflection channel (6) away from the reflecting end (61), and the exit end (62) passes through the exit straight surface (12) to reach the outside of the exit straight surface (12); The ejector end (62) is connected to one end of the capillary tube (2), which is a hollow tube. The other end of the capillary tube (2) is the left end face (21), which is connected to the second air chamber (3). The second air chamber (3) includes a second channel (31), a second window (32), and a second outlet hole (35). The second channel (31) includes a second inlet end (311) and a second reflective end (312). The second inlet end (311) is connected to the left end face (21). The second reflective end (312) is located at the end of the second channel (31) away from the second inlet end (311). The second reflective end (312) is connected to one end of the second window (32). The second window (32) is connected to the left end face (21). The distance between them is greater than 10 cm. The normals of the second window piece (32) and the second channel (31) form an inclined angle (34) greater than 5 degrees. The other end of the second window piece (32) is connected to the second outlet hole (35). The second outlet hole (35) is located on the end of the second air chamber (3) away from the second channel (31). An air outlet channel (36) is also provided in the middle of the second channel (31). One end of the air outlet channel (36) is connected to the outer surface of the second air chamber (3).

2. The gas cell device for Raman spectroscopy detection without quartz Raman signal according to claim 1, characterized in that: The outer side of the ejector end (62) is fitted with a rubber tube (63), and the outer side of the rubber tube (63) is fitted with a clamp (64); A capillary seal (7) is fitted on one end of the capillary tube (2) connected to the outlet end (62). The capillary seal (7) includes a capillary pressure member (71) and a spherical washer (72). The spherical washer (72) is fitted on the outside of the end of the capillary tube (2) connected to the outlet end (62). The capillary pressure member (71) includes a threaded end (711) and a hollow part (712). The hollow part (712) is fitted on the outside of the end of the capillary tube (2) connected to the outlet end (62). The threaded end (711) is located on the end of the capillary pressure member (71) near the connecting end (42). The threaded end (711) and the spherical washer (72) are inserted into one end of the rubber tube (63). The threaded end (711) is connected to one end of the spherical washer (72).

3. The gas cell device for Raman spectroscopy detection without quartz Raman signal according to claim 2, characterized in that: The left end face (21) is covered with a capillary seal (7); The capillary seal (7) includes a capillary clamp (71) and a spherical washer (72). The spherical washer (72) is fitted on the outside of the left end face (21). The capillary clamp (71) includes a threaded end (711) and a hollow part (712). The hollow part (712) is fitted on the outside of the left end face (21). The threaded end (711) is located on the end of the capillary clamp (71) near the second inlet end (311). The threaded end (711) and the spherical washer (72) are inserted into the interior of the second air chamber (3) near the second inlet end (311). The threaded end (711) is connected to one end of the spherical washer (72).

4. The gas cell device for Raman spectroscopy detection without quartz Raman signal according to claim 3, characterized in that: The dichroic mirror (5) is fitted with a dichroic spherical washer (51) on the outside. The dichroic spherical washer (51) is provided with an external thread (52) on the outside. The external thread (52) is connected to the middle part of the reflecting slope (13).

5. The gas cell device for Raman spectroscopy detection without quartz Raman signal according to claim 1, characterized in that: The diameter of the reflecting end (61) is greater than the diameter of the emitting end (62), and the diameter of the emitting end (62) is greater than the diameter of the laser incident channel (4).

6. The gas cell device for Raman spectroscopy detection without quartz Raman signal according to claim 5, characterized in that: The second inlet end (311) is connected to one end of the second connection end (313), the other end of the second connection end (313) is connected to one end of the second large end (314), and the other end of the second large end (314) is connected to one end of the second reflective end (312). The diameter of the second large end (314) is greater than the diameter of the second reflective end (312), the diameter of the second reflective end (312) is greater than the diameter of the second connecting end (313), and the diameter of the second connecting end (313) is greater than the diameter of the second inlet end (311).

7. The gas cell device for Raman spectroscopy detection without quartz Raman signal according to claim 6, characterized in that: The diameter of the reflecting end (61) is 12 mm, the diameter of the emitting end (62) is 10 mm, and the diameter of the laser incident channel (4) is 8 mm.

8. The gas cell device for Raman spectroscopy detection without quartz Raman signal according to claim 1, characterized in that: The incident straight surface (11) has four connecting holes (15) evenly distributed around its perimeter, and the exit straight surface (12) has four connecting holes (15) evenly distributed around its perimeter.

9. A gas cell device for Raman spectroscopy detection without quartz Raman signal according to claim 8, characterized in that: The second outlet hole (35) is vertically connected to a cage-type connector (37), which is a hollow cylinder.

10. A gas cell device for Raman spectroscopy detection without quartz Raman signal according to claim 9, characterized in that: The inner surface of the air intake pipe (43) is uniformly distributed with threaded structures, and the inner surface of the air outlet channel (36) is uniformly distributed with threaded structures.

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