CN218974169U

CN218974169U - Reflection type air chamber for gas sensing

Info

Publication number: CN218974169U
Application number: CN202320672368.7U
Authority: CN
Inventors: 许清
Original assignee: Wuhan Linglan Photoelectric Technology Co ltd
Current assignee: Wuhan Linglan Photoelectric Technology Co ltd
Priority date: 2023-03-30
Filing date: 2023-03-30
Publication date: 2023-05-05
Anticipated expiration: 2033-03-30

Abstract

The utility model belongs to the technical field of gas detection, and particularly provides a reflective gas chamber for gas sensing, which is constructed according to the design thought of light beam splitting, partial light beams are emitted at different light paths of light beam propagation, the light beams can be split according to the requirements or emitted into different photoelectric detectors at different wavelengths, and the light paths are greatly increased under the condition of unchanged volume through a light path laminated structure in a limited gas chamber volume. The problems that in the prior art, when trace single gas exists, accurate measurement of high-concentration gas and low-concentration gas cannot be compatible, the reliability of an optical structure is low, the stability of an optical path is poor, and the measurement result is unreliable are solved; and when trace gases with different spectral absorption coefficients are used, a plurality of air chamber structures are needed, so that the TDLAS gas detection system has the problems of large volume, high cost, multiple parts and complex equipment structure.

Description

Reflection type air chamber for gas sensing

Technical Field

The utility model belongs to the technical field of gas detection, and particularly relates to a reflective gas chamber for gas sensing.

Background

The TDLAS (Tunable Diode Laser Absorption Spectroscopy) technology is based on a tunable diode laser, and utilizes the characteristic of frequency selection of measured gas molecules to realize the measurement of the measured gas characteristics. The method successfully avoids the interference of other gas components and becomes the optimization of the scheme of the current accurate real-time online gas detection system. Meanwhile, the method has the advantages of high response speed and low measurement lower limit, and can simultaneously analyze various gas components, mainly including methane, carbon monoxide, carbon dioxide, oxygen, ammonia, ethylene, acetylene and other gases. Therefore, in the late nineties, gas detection schemes and devices based on TDLAS technology have emerged as spring shoots, and various measurement modes such as fixed test systems, distributed test systems, portable test systems, and telemetry test systems have appeared in the field of industrial application.

As known from Beer-Lambert Law (Beer-Lambert Law), the optical path and the gas absorption intensity are positively correlated, so that the shorter the optical path is, the lower the resolution of the detector is; the short-path gas chamber is suitable for a high-concentration gas environment or a measurement environment with a large gas spectral absorption coefficient. The longer the optical path, the higher the detector resolution; therefore, the long-optical-path gas chamber is more suitable for a low-concentration gas environment or a measurement environment with a small gas spectral absorption coefficient.

However, most industrial application environments have uncertain environments of the concentration of the detected gas, and sometimes the concentration of the gas is high and sometimes low. Or multiple gases may exist in the measured gas environment at the same time, and the situation that multiple gases cannot be measured at the same time occurs.

The reflective air chamber used in the diffusion-based gas detector in the current market has the following problems:

1. the optical path in the gas chamber is fixed when trace single gas exists, and the accurate measurement of high-concentration gas and low-concentration gas cannot be compatible.

2. The variable-range air chamber in the current market has complex internal optical structure, high cost and low reliability. In particular, in a high-density long-optical-path air chamber, the variable optical structure causes low structural reliability, poor optical path stability and high measurement result unreliability.

3. When trace gases with different spectral absorption coefficients are used, a plurality of air chamber structures are needed, so that the TDLAS gas detection system is large in size, high in cost, multiple in parts and complex in equipment structure.

Therefore, the utility model provides a reflective air chamber which can be applied to a full-range real-time online detection system of a diffuse TDLAS and a multi-gas real-time online detection system of the diffuse TDLAS.

Disclosure of Invention

The utility model aims to solve the problems that in the prior art, when trace single gas exists, the accurate measurement of high-concentration gas and low-concentration gas cannot be compatible, the reliability of an optical structure is low, the stability of an optical path is poor, and the measurement result is unreliable; and when trace gases with different spectral absorption coefficients are used, a plurality of air chamber structures are needed, so that the TDLAS gas detection system has the problems of large volume, high cost, multiple parts and complex equipment structure.

The utility model provides a reflection type air chamber for gas sensing, which comprises an air chamber tube shell, wherein a fixed reflector I is arranged on the inner wall of the front side of the air chamber tube shell; the left side and the right side of the fixed reflector I are respectively provided with a light incident hole and a light emergent hole II; the surface of the light-emitting hole II is covered with a light-splitting reflector II; a fixed reflector III is arranged above the light splitting reflector II; a fixed reflector II parallel to the fixed reflector I is arranged on the inner wall of the rear side of the air chamber tube shell; the left side and the right side of the fixed reflector II are respectively provided with a light emitting hole I and a light beam lifting and rotating structure; the light emitting hole I corresponds to the light incident hole; the surface of the light-emitting hole I is covered with a light-splitting reflector I; a light emergent hole III is arranged above the light splitting reflector I; light entering from the light incident hole sequentially passes through the light splitting reflector I, the fixed reflector II and the light splitting reflector II to form a lower layer zigzag light path; the light beam rising and turning structure receives light rays reflected by the light splitting reflector II, reflects the light rays to the upper fixed reflector III, forms an upper zigzag light path through the fixed reflector III, the fixed reflector II and the fixed reflector I, and finally emits the light rays through the light emitting hole III; the upper zigzag light path is parallel to the lower zigzag light path, and the propagation directions of the light beams are opposite.

Specifically, the gas sensing reflection type gas chamber also comprises a photoelectric detector I, a photoelectric detector II and a photoelectric detector III which are arranged on the outer wall of the gas chamber tube shell; the photoelectric detector I is arranged at the light-emitting hole I; the photoelectric detector II is arranged at the light-emitting hole II; the photodetector III is mounted at the light exit aperture III.

Specifically, a collimated light incident device is arranged at the light incident hole.

Specifically, the gas sensing reflective gas chamber also comprises a coupling pagoda sleeve and an inclined plane cylindrical boss which is prefabricated on the outer wall of the gas chamber tube shell; the collimated light incident device passes through the coupling pagoda sleeve and is fixed after coupling adjustment; the coupling pagoda sleeve is fixed on the inclined plane cylindrical boss after coupling adjustment; the light incident hole penetrates through the inclined plane cylindrical boss and the air chamber tube shell.

Specifically, the collimating light incident device is a passive optical fiber collimator or an active laser component with a collimating lens.

Specifically, the beam rising and turning structure comprises a beam turning bracket, a turning reflector I and a turning reflector II, wherein the turning reflector I and the turning reflector II are fixed on the beam turning bracket; the beam turning support is an isosceles trapezoid body, and is internally provided with a beam turning inlet hole, a beam turning outlet hole and a beam lifting hole; the bottom surface of the beam turning support is fixed on the side wall of the air chamber tube shell, the beam turning inlet hole penetrates through the side wall of the air chamber tube shell and one side waist surface of an isosceles trapezoid of the beam turning support, the beam turning outlet hole penetrates through the side wall of the air chamber tube shell and the other side waist surface of the beam turning support, and the beam lifting hole is communicated with the beam turning inlet hole and the beam turning outlet hole; the turning reflector I completely covers the beam turning incidence hole; the turning reflector II completely covers the beam turning exit hole.

Specifically, the fixed reflecting mirror I, the fixed reflecting mirror II, the fixed reflecting mirror III, the turning reflecting mirror I and the turning reflecting mirror II are all plated with HR dielectric films.

Specifically, the light-splitting reflector I and the light-splitting reflector II are both plated with a light-intensity light-splitting film or a wavelength light-splitting film.

Specifically, the air chamber tube shell is sleeved with a diffusion type sealing cover, and a molecular filtering structure is arranged in the diffusion type sealing cover.

Specifically, a temperature pressure sensor is further arranged on the inner wall of the air chamber tube shell, and the temperature pressure sensor is close to the light emergent hole II.

Compared with the prior art, the utility model has the following advantages and beneficial effects:

1. the reflection type gas chamber for gas sensing is constructed according to the design thought of light splitting, partial light is emitted at different light paths of light beam propagation, and the light can be split into light intensity or wavelength according to the requirement and emitted into different photoelectric detectors. Thereby realizing the functions of one air chamber, multiple optical paths and multiple measuring ranges.

2. The reflective air chamber for gas sensing provided by the utility model can realize that light beams with the same wavelength are divided into three light beams, and the light paths of the three light beams are different and are divided into short, medium and long. From Beer-Lambert Law (Beer-Lambert Law), it is known that the optical path length and the gas absorption intensity are positively correlated. Therefore, the reflection type air chamber can solve the problem of full-range high precision when the air chamber is used for trace single gas. I.e. trace of the photodetector at the long optical path for low concentration gas and trace of the photodetector at the short optical path for high concentration gas. The accuracy of measuring gases with different concentrations is ensured, and the adaptability to the environment is improved.

3. The reflective gas chamber for gas sensing provided by the utility model can demultiplex composite light beams passing through the gas chamber, namely light beams with different wavelengths, at the tail ends of respective designed optical paths, namely, the composite light beams are one by one unwound into three light beams with single wavelength at different optical paths, and the optical paths of the three light beams with different wavelengths are different and are divided into short, medium and long. From Beer-Lambert Law, it is known that the optical path and the gas absorption coefficient are positively correlated with the gas absorption intensity. Therefore, the scheme can realize the matching of the absorption coefficient and the optical path when the gases with different spectral absorption coefficients are trace, and ensure the simultaneous high-precision detection of different gases. I.e. trace of photodetector at long optical path for low absorption coefficient gas and trace of photodetector at short optical path for high absorption coefficient gas. The measuring precision of different gases in the simultaneous measurement is ensured, and the environmental adaptability of complex gas measurement is increased.

4. The utility model realizes the function of raising, rotating and spreading the light path by using the prefabricated isosceles trapezoid structure and the light beam raising and rotating structure which is formed by three simple through round holes and the reflecting mirror fixed on the waist surface of the isosceles trapezoid on the reflective air chamber. In the limited air chamber volume, the optical path is greatly increased under the condition of unchanged volume by the optical path lamination structure.

5. According to the utility model, through small-amplitude angle swing adjustment of the collimating light incident device in the inner hole of the coupling pagoda sleeve, the incident angle adjustment of the incident collimating light beam relative to the reflecting mirror can be realized, so that the reflecting period of the light beam is adjusted; the movement of the collimation light incidence device in XY direction can realize that the incidence collimation light beam can be accurately coupled to the photoelectric detector I, the photoelectric detector II and the photoelectric detector III. The coaxial structure is simple and reliable, and the coupling alignment of the long-optical-path multi-reflection air chamber is realized by only using single optical parts for coupling. The reliability of the product is improved, the process complexity is reduced, and the product cost is reduced.

The present utility model will be described in further detail with reference to the accompanying drawings.

Drawings

Fig. 1 is a right side view of a multi-range reflective plenum structure in embodiment 1 of the present utility model.

Fig. 2 is a left side view of the multi-range reflective plenum structure of embodiment 1 of the present utility model.

Fig. 3 is a top view of a multi-range reflective plenum structure in embodiment 1 of the utility model.

Fig. 4 is a cross-sectional view of the A-A plane in fig. 3.

Fig. 5 is a right side view of the multi-gas, multi-range reflective plenum structure of example 2 of the present utility model.

FIG. 6 is a left side view of the multi-gas, multi-range reflective plenum structure of example 2 of the present utility model.

Reference numerals: 1. an air chamber tube shell; 2. a fixed reflector I; 3. a fixed reflector II; 4. a fixed mirror III; 5. a light splitting reflector I; 6. a light splitting reflector II; 7. turning a reflector I; 8. turning a reflector II; 9. a light entrance hole; 10. a light exit hole I; 11. a light exit hole II; 12. a light exit aperture III; 13. a temperature and pressure sensor; 14. a diffusion type sealing cover; 15. a photodetector I; 16. a photoelectric detector II; 17. a photodetector III; 18. a collimated light source; 19. coupling the pagoda sleeve; 20. inclined plane cylinder boss; 21. a beam turning bracket; 22. the beam turns into the hole; 23. the beam turns the exit hole; 24. a beam elevation hole; 25. HR dielectric film; 26. a light intensity splitting film; 27. wavelength splitting film.

Detailed Description

The technical solutions of the present utility model will be clearly and completely described in the following examples, and it is obvious that the described examples are only some examples of the present utility model, but not all examples. Although representative embodiments of the present utility model have been described in detail, those skilled in the art to which the utility model pertains will appreciate that various modifications and changes can be made without departing from the scope of the utility model. Accordingly, the scope of the utility model should not be limited to the embodiments, but should be defined by the appended claims and equivalents thereof.

In the description of the present utility model, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, merely to facilitate describing the present utility model and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model. In the description of the present utility model, unless otherwise indicated, the meaning of "a plurality" is two or more.

The utility model provides a reflection type air chamber for gas sensing, which comprises an air chamber tube shell 1, wherein a fixed reflecting mirror I2 is arranged on the inner wall of the front side of the air chamber tube shell 1; the left side and the right side of the fixed reflector I2 are respectively provided with a light incident hole 9 and a light emergent hole II 11; the surface of the light-emitting hole II 11 is covered with a light-splitting reflector II 6; a fixed reflector III 4 is arranged above the light splitting reflector II 6; a fixed reflector II 3 parallel to the fixed reflector I2 is arranged on the inner wall of the rear side of the air chamber tube shell 1; the left side and the right side of the fixed reflector II 3 are respectively provided with a light emitting hole I10 and a light beam lifting and rotating structure; the light exit hole i 10 corresponds to the light entrance hole 9; the surface of the light-emitting hole I10 is covered with a light-splitting reflector I5; a light emergent hole III 12 is arranged above the light splitting reflector I5; light entering from the light incidence hole 9 sequentially passes through the light splitting reflector I5, the fixed reflector I2, the fixed reflector II 3 and the light splitting reflector II 6 to form a lower layer zigzag light path; the light beam rising and turning structure receives the light reflected by the light splitting reflector II 6, reflects the light to the upper fixed reflector III 4, forms an upper zigzag light path through the fixed reflector III 4, the fixed reflector II 3 and the fixed reflector I2, and finally emits the light through the light emitting hole III 12; the upper zigzag light path is parallel to the lower zigzag light path, and the propagation directions of the light beams are opposite.

In actual use, the photoelectric detector I15, the photoelectric detector II 16 and the photoelectric detector III 17 can be arranged on the outer wall of the air chamber tube shell 1; the photoelectric detector I15 is arranged at the light emergent hole I10; the photoelectric detector II 16 is arranged at the light-emitting hole II 11; the photodetector iii 17 is mounted at the light exit hole iii 12. The light beam enters from the light incidence hole 9 and enters the light splitting reflector I5 at a certain included angle, wherein part of the light beam is transmitted from the light splitting reflector I5, and the transmitted light beam exits from the light exit hole I10 and is collected by the photoelectric detector I15. The residual light beam is reflected by the light splitting reflector I5, and reaches the light splitting reflector II 6 after being reflected for multiple times by the fixed reflector I2 and the fixed reflector II 3, so that a lower-layer tooth-shaped light path is formed. The beam splitting reflector II 6 transmits part of the light beams, the transmitted light beams are emitted from the light emitting hole II 11 and collected by the photoelectric detector II 16. The residual light beam is continuously reflected to a light beam rising rotating structure by the light splitting reflector II 6, the light beam rising rotating structure receives the light beam reflected by the light splitting reflector II 6 and reflects the light beam to the upper fixed reflector III 4, an upper zigzag light path which is parallel to the lower zigzag light path and opposite in light beam propagation direction is formed by the fixed reflector III 4, the fixed reflector II 3 and the fixed reflector I2, and the light beam finally exits through the light exit hole III 12 and is collected by the photoelectric detector III 17. The light beams are partially emitted at different light path positions of propagation through the light emitting holes I10, II 11 and III 12, and can be emitted into different photodetectors according to the required light splitting intensity or wavelength. Thereby realizing the functions of one air chamber, multiple optical paths and multiple measuring ranges.

Further, a collimated light source 18 is disposed at the light incident hole 9, and the collimated light source 18 is used to shape the light beam into collimated light and emit the collimated light from the light incident hole 9, and the collimated light source 18 may be a passive optical fiber collimator or an active laser assembly with a collimating lens.

Specifically, the gas sensing reflective gas chamber further comprises a coupling pagoda sleeve 19 and an inclined plane cylindrical boss 20 which is prefabricated on the outer wall of the gas chamber tube shell 1; the collimated light incident device 18 passes through the coupling pagoda sleeve 19 and is fixed after coupling adjustment; the coupling pagoda sleeve 19 is fixed on the inclined plane cylindrical boss 20 after coupling adjustment; the light-entering hole 9 penetrates the inclined plane cylindrical boss 20 and the air chamber tube shell 1. The light path coupling of the reflective air chamber is realized by the XY-axis movement of the coupling collimation light incidence device 18 and the angle swing of the collimation light incidence device 18 in the inner hole of the coupling pagoda sleeve 19, and the incident light beam is coupled to the light emergent hole I10, the light emergent hole II 11 and the light emergent hole III 12 after direct correlation or multiple reflection. The incident angle of the incident collimated light beam relative to the reflector can be adjusted by small-amplitude angle swing adjustment of the collimated light incident device 18 in the inner hole of the coupling pagoda sleeve 19, so that the reflection period of the light beam is adjusted; the movement of the collimation light incidence device 18 in XY direction can realize that the incident collimation light beam can be accurately coupled to the photoelectric detector I15, the photoelectric detector II 16 and the photoelectric detector III 17. The coaxial structure is simple and reliable, only single optical part coupling is used, long-optical-path multiple reflection air chamber coupling alignment is realized, reliability of products is improved, process complexity is reduced, and product cost is reduced.

In a refined embodiment, the beam lifting and turning structure comprises a beam turning bracket 21, and a turning mirror I7 and a turning mirror II 8 which are fixed on the beam turning bracket 21; the beam turning support 21 is an isosceles trapezoid body, and is internally provided with a beam turning inlet hole 22, a beam turning outlet hole 23 and a beam lifting hole 24; the bottom surface of the beam turning support 21 is fixed on the side wall of the air chamber tube shell 1, the beam turning inlet hole 22 penetrates through the side wall of the air chamber tube shell 1 and one side waist surface of an isosceles trapezoid of the beam turning support 21, the beam turning outlet hole 23 penetrates through the side wall of the air chamber tube shell 1 and the other side waist surface of the beam turning support 21, and the beam lifting hole 24 is communicated with the beam turning inlet hole 22 and the beam turning outlet hole 23; the turning mirror I7 completely covers the beam turning entrance hole 22; the turning mirror ii 8 completely covers the beam turning exit hole 23. The beam turning support 21, the beam turning incident hole 22, the turning mirror I7, the beam raising hole 24, the turning mirror II 8 and the beam turning exit hole 23 form a beam raising rotation structure. The light reflected by the light splitting reflector II 6 is received and reflected by the turning reflector I7 after passing through the light beam turning incidence hole 22, the reflected light is transmitted to the turning reflector II 8 through the light beam lifting hole 24, and the reflected light returns to the air chamber tube shell 1 through the light beam turning incidence hole 23 after being reflected, and forms an upper zigzag light path through the fixed reflector III 4, the fixed reflector II 3 and the fixed reflector I2, and finally is emitted through the light emitting hole III 12. Because the beam turning support 21 is isosceles trapezoid, the bottom surface with larger area is fixed on the air chamber tube shell 1, the turning reflector I7 and the turning reflector II 8 are respectively fixed on two waist surfaces, the turning reflector I7 and the turning reflector II 8 reflect the lower-layer light path beam twice and then re-etch the lower-layer light path to the upper-layer light path, and emergent light of the beam rising and turning structure is parallel to incident light, but the beam propagation directions are opposite.

The reflection type air chamber has the advantages that the reflection type air chamber has the functions of lifting, rotating and spreading the light path by the prefabricated isosceles trapezoid structure, three simple penetrating round holes and the reflecting mirror fixed on the waist surface of the isosceles trapezoid, and the structure is simple to process, low in cost and high in reliability. The lower layer optical path and the upper layer optical path can be consistent in propagation path but opposite in direction. In the limited air chamber volume, the optical path is greatly increased under the condition of unchanged volume by the optical path lamination structure.

Further, the fixed mirror I2, the fixed mirror II 3, the fixed mirror III 4, the turning mirror I7 and the turning mirror II 8 are all plated with the HR dielectric film 25. The light splitting reflector I5 and the light splitting reflector II 6 are both plated with a light intensity splitting film 26. The light beams with the same wavelength can be divided into three light beams, and the light paths of the three light beams are different and are divided into short light beams, medium light beams and long light beams. From Beer-Lambert Law (Beer-Lambert Law), it is known that the optical path length and the gas absorption intensity are positively correlated. Therefore, the scheme can solve the problem of full-range high precision when a single gas is trace. I.e. trace of the photodetector at the long optical path for low concentration gas and trace of the photodetector at the short optical path for high concentration gas. The measuring precision of gases with different concentrations is ensured, and the environmental adaptability is increased.

The light-splitting mirror I5 and the light-splitting mirror II 6 can be plated with a wavelength light-splitting film 27. The composite light beams passing through the air chamber, namely light beams with different wavelengths, can be demultiplexed at the tail ends of respective designed optical paths, namely the composite light beams are disassembled into three light beams with single wavelength one by one at different optical paths, and the optical paths of the three light beams with different wavelengths are different and are divided into short, medium and long. From Beer-Lambert Law, it is known that the optical path and the gas absorption coefficient are positively correlated with the gas absorption intensity. Therefore, the scheme can realize the matching of the absorption coefficient and the optical path when the gases with different spectral absorption coefficients are trace, and ensure the simultaneous high-precision detection of different gases. I.e. trace of photodetector at long optical path for low absorption coefficient gas and trace of photodetector at short optical path for high absorption coefficient gas. The measuring precision of different gases in the simultaneous measurement is ensured, and the environmental adaptability of complex gas measurement is increased.

Further, a diffusion type sealing cover 14 is sleeved outside the air chamber tube shell 1, and the diffusion type sealing cover 14 is fixed with the air chamber tube shell 1 in a sealing way. The inside of the diffusion type sealing cover 14 is provided with a molecular filtering structure, so that dust and water vapor can be blocked outside the sealing cover, and normal gas can normally pass through the sealing cover to enter the air chamber.

Further, a temperature pressure sensor 13 is further disposed on the inner wall of the air chamber tube shell 1, and the temperature pressure sensor 13 is close to the light exit hole ii 11. And the tail part of the temperature and pressure sensor 13 is sealed by glue filling, so that the gas leakage phenomenon between the temperature and pressure sensor 13 and the air chamber tube shell 1 can not occur.

The effect of the reflective gas cell for gas sensing of the present utility model is examined by the following specific examples.

Example 1:

as shown in fig. 1-4, the present embodiment provides a reflective gas chamber for gas sensing, which comprises a gas chamber tube shell 1, a collimated light incident device 18, a coupling pagoda sleeve 19, an inclined plane cylindrical boss 20 pre-processed on the outer wall of the gas chamber tube shell 1, a diffusion seal cover 14 and a temperature pressure sensor 13;

a fixed reflector I2 is arranged on the inner wall of the front side of the air chamber tube shell 1; the left side and the right side of the fixed reflector I2 are respectively provided with a light incident hole 9 and a light emergent hole II 11; one end surface of the light-emitting hole II 11 is covered with a light-splitting reflector II 6, and the other end is provided with a photoelectric detector II 16; a fixed reflector III 4 is arranged above the light splitting reflector II 6; a fixed reflector II 3 parallel to the fixed reflector I2 is arranged on the inner wall of the rear side of the air chamber tube shell 1; the left side and the right side of the fixed reflector II 3 are respectively provided with a light emitting hole I10 and a light beam lifting and rotating structure; the light exit hole i 10 corresponds to the light entrance hole 9; one end surface of the light-emitting hole I10 is covered with a light-splitting reflector I5, and the other end is provided with a photoelectric detector I15; a light emergent hole III 12 is arranged above the light splitting reflector I5, and a photoelectric detector III 17 is arranged at one end of the light emergent hole III 12, which is communicated with the outside of the air chamber tube shell 1; light entering from the light incidence hole 9 sequentially passes through the light splitting reflector I5, the fixed reflector I2, the fixed reflector II 3 and the light splitting reflector II 6 to form a lower layer zigzag light path;

the beam lifting and turning structure comprises a beam turning bracket 21, and a turning reflector I7 and a turning reflector II 8 which are fixed on the beam turning bracket 21; the beam turning support 21 is an isosceles trapezoid body, the bottom surface of the beam turning support is parallel to the inclined surface of the inclined cylindrical boss 20, and a beam turning inlet hole 22, a beam turning outlet hole 23 and a beam lifting hole 24 are formed in the beam turning support; the bottom surface with larger area of the beam turning support 21 is fixed on the side wall of the air chamber tube shell 1, the beam turning inlet hole 22 penetrates through the side wall of the air chamber tube shell 1 and one side waist surface of an isosceles trapezoid of the beam turning support 21, the beam turning outlet hole 23 penetrates through the side wall of the air chamber tube shell 1 and the other side waist surface of the beam turning support 21, and the beam lifting hole 24 is communicated with the beam turning inlet hole 22 and the beam turning outlet hole 23; the turning mirror I7 completely covers the beam turning entrance hole 22; the turning mirror II 8 completely covers the beam turning exit hole 23; the beam turning support 21, the beam turning incident hole 22, the turning mirror I7, the beam lifting hole 24, the turning mirror II 8 and the beam turning exit hole 23 form a beam lifting and turning structure; the light reflected by the light splitting reflector II 6 is received and reflected by the turning reflector I7 after passing through the light beam turning incidence hole 22, the reflected light is transmitted to the turning reflector II 8 through the light beam lifting hole 24, and the reflected light returns to the air chamber tube shell 1 through the light beam turning incidence hole 23 after being reflected, and forms an upper zigzag light path through the fixed reflector III 4, the fixed reflector II 3 and the fixed reflector I2, and finally is emitted through the light emitting hole III 12; the upper zigzag light path is parallel to the lower zigzag light path, and the propagation directions of the light beams are opposite;

the collimated light incident device 18 passes through the coupling pagoda sleeve 19, is subjected to coupling adjustment and then is welded and fixed; the coupling pagoda sleeve 19 is welded and fixed on the inclined plane cylindrical boss 20 after coupling adjustment; the light incidence hole 9 penetrates through the inclined plane cylindrical boss 20 and the air tube shell 1; the light path coupling of the reflective air chamber is realized by the XY axis movement of the coupling collimation light incidence device 18 and the angle swing of the collimation light incidence device 18 in the inner hole of the coupling pagoda sleeve 19, and the incident light beam is coupled to the photoelectric detector I15, the photoelectric detector II 16 and the photoelectric detector III 17 after direct correlation or multiple reflection.

The fixed reflector I2, the fixed reflector II 3, the fixed reflector III 4, the turning reflector I7 and the turning reflector II 8 are plated with HR dielectric films 25; the light splitting reflector I5 and the light splitting reflector II 6 are respectively plated with a light intensity splitting film 26;

the diffusion type sealing cover 14 is fixed with the air chamber tube shell 1 in a sealing way, and a molecular filtering structure is arranged in the diffusion type sealing cover 14;

the temperature and pressure sensor 13 is arranged on the inner wall of the air chamber tube shell 1 and is close to the light emergent hole II 11.

The beam is shaped into collimated light by a collimated light source 18, which is emitted from the light entrance aperture 9, and the collimated light source 18 may be a passive fiber collimator or an active laser assembly with a collimating lens.

The preparation method of the reflective air chamber for gas sensing provided by the embodiment is as follows:

s101, fixing a reflector I2 on the same side of the inner wall of the air chamber tube shell 1 and the light incident hole 9, and between the light incident hole 9 and the light emergent hole II 11; the fixed reflector II 3 is fixed on the inner wall of the air chamber tube shell 1, is parallel to and opposite to the fixed reflector I2, and is positioned between the light emergent hole I10 and the light beam turning incident hole 22; the fixed reflector III 4 is fixed on the inner wall of the air chamber tube shell 1 and is positioned beside the same side of the fixed reflector I2 and above the light emitting hole II 11.

S102, fixing a light splitting reflector I5 plated with a light intensity splitting film 26 on the inner wall of the air chamber tube shell 1, and completely covering the light emitting hole I10; the light splitting reflector II 6 coated with the light intensity splitting film 26 is fixed on the inner wall of the air chamber tube shell 1 and completely covers the light emergent hole II 11.

S103, fixing a turning reflector I7 on one side waist surface of an isosceles trapezoid structure of the beam turning support 21, and completely covering the beam turning entrance hole 22; the turning mirror II 8 is fixed on the waist surface of the other side of the isosceles trapezoid structure of the beam turning support 21 and completely covers the beam turning exit hole 23.

S104, the photoelectric detector I15, the photoelectric detector II 16 and the photoelectric detector III 17 are respectively inserted into the light emergent hole I10, the light emergent hole II 11 and the mounting hole behind the light emergent hole III 12 in sequence to be fixed.

S105, the temperature pressure sensor 13 is fixed in the air chamber tube shell 1 and is positioned beside the light emergent hole II 11, and the tail part of the temperature pressure sensor 13 is sealed by glue filling, so that the gas leakage phenomenon between the temperature pressure sensor 13 and the air chamber tube shell 1 can not occur.

S106, inserting the collimated light incident device 18 into an inner hole of the coupling pagoda sleeve 19, and then attaching and placing the bottom surface of the coupling pagoda sleeve 19 on the inclined plane cylindrical boss 20 for coupling alignment.

S107, through adjusting XY axis movement of the collimating light incident device 18 and coupling the collimating light incident device 18 through angle swing of an inner hole of the coupling tower sleeve 19, after responsivity of the photoelectric detector I15, the photoelectric detector II 16 and the photoelectric detector III 17 is more than or equal to 0.6mA/mW, the collimating light incident device 18 is fixed on the coupling tower sleeve 19 through laser welding, and the coupling tower sleeve 19 is fixed on an inclined plane of the inclined plane cylindrical boss 20 through laser welding.

S108, filling and sealing a gap between the coupling pagoda sleeve 19 and the air chamber tube shell 1 and a gap between the collimated light incident device 18 and the coupling pagoda sleeve 19 by using seam filling glue.

And S109, the diffusion type sealing cover 14 is pressed and connected to the air chamber tube shell 1 by a sealing gasket, so that the sealing cover of the air chamber is realized, and the protection and isolation effects on the internal optical components are realized.

The working principle of the multi-range reflective air chamber for single gas measurement in the embodiment is as follows:

the collimating light incident device 18 emits a collimated single-wavelength 1653nm long beam, the beam passes through the light incident hole 9 to enter the reflective air chamber, and the beam is opposite to the light splitting reflector I5 in the reflective air chamber through the XY axis of the coupling collimating light incident device 18 and the angle swing adjustment of the collimating light incident device 18 in the inner hole of the coupling pagoda sleeve 19, the surface of the light splitting reflector I5 is plated with a light intensity beam splitting film 26, and the light intensity beam splitting film 26 can transmit the beam with 1/3 light intensity to the photoelectric detector I15 for short-path measurement through the light emitting hole I10; the rest 2/3 light beams are reflected by the light splitting reflector I5, and reach the light splitting reflector II 6 after being reflected for multiple times by the fixed reflector I2 and the fixed reflector II 3 in sequence, the surface of the light splitting reflector II 6 is also plated with a light intensity light splitting film 26, and the light intensity light splitting film 26 transmits 1/3 light beams to the photoelectric detector II 16 for medium optical path measurement through the light exit hole II 11, so that the propagation path of the lower layer light path of the light beams is completed; finally, the remaining 1/3 beam is reflected by the light intensity beam splitting film 26 on the surface of the beam splitting reflector II 6, reaches the beam turning incident hole 22, then reaches the turning reflector I7, passes through the beam lifting hole 24 to the turning reflector II 8 after single total reflection, and passes through the beam turning emergent hole 23 after single total reflection, so that lifting and resculpting of the beam paths are completed, namely the propagation path tracks of the lower layer optical path and the upper layer optical path are consistent, but the propagation directions are opposite, and the layers are highly layered. The 1/3 light beam after the re-etching sequentially passes through the fixed reflector III 4, the fixed reflector II 3 and the fixed reflector I2 for multiple reflections, and then enters the light emergent hole III 12 to reach the photoelectric detector III 17 for long-path measurement, wherein in the embodiment, the short-path light path is 50mm, the medium-path light path is 500mm and the long-path light path is 1050mm.

Example 2:

referring to fig. 5-6, the present embodiment provides a reflective gas chamber for gas sensing, which comprises a gas chamber tube shell 1, a collimated light incident device 18, a coupling pagoda sleeve 19, an inclined plane cylindrical boss 20 pre-processed on the outer wall of the gas chamber tube shell 1, a diffusion type sealing cover 14 and a temperature pressure sensor 13;

The fixed reflector I2, the fixed reflector II 3, the fixed reflector III 4, the turning reflector I7 and the turning reflector II 8 are plated with HR dielectric films 25; the light splitting reflector I5 and the light splitting reflector II 6 are respectively plated with a wavelength light splitting film 27;

s101, fixing a reflector I2 on the same side of the inner wall of the air chamber tube shell 1 and the light incident hole 9, and positioning the reflector I between the light incident hole 9 and the light emergent hole II 11; the fixed reflector II 3 is fixed on the inner wall of the air chamber tube shell 1, is parallel to and opposite to the fixed reflector I2, and is positioned between the light emitting hole I10 and the light beam turning incident hole 22; the fixed reflector III 4 is fixed on the inner wall of the air chamber tube shell 1 and is positioned beside the same side of the fixed reflector I2 and above the light emitting hole II 11.

S102, fixing a light splitting reflector I5 plated with a wavelength light splitting film 27 on the inner wall of the air chamber tube shell 1, and completely covering the light emitting hole I10; the spectroscope II 6 coated with the wavelength spectroscope 27 is fixed on the inner wall of the air chamber tube 1 and completely covers the light exit hole II 11.

S105, a temperature and pressure sensor 13 is fixed in the air chamber tube shell 1 and is positioned beside the light emergent hole II 11. And the tail part of the temperature and pressure sensor 13 is sealed by glue filling, so that the gas leakage phenomenon between the temperature and pressure sensor 13 and the air chamber tube shell 1 can not occur.

In this embodiment, the working principle of the multi-range reflective air chamber for multi-gas measurement is as follows:

the collimating light incident device 18 emits a collimated composite multi-wavelength light beam which comprises 1512nm wavelength measurement ammonia, 1653nm wavelength measurement methane and 1627nm wavelength measurement ethylene, the composite multi-wavelength light beam passes through the light incident hole 9 to enter the reflective air chamber, and the light beam is opposite to a light splitting reflector I5 in the reflective air chamber by coupling the XY axis of the collimating light incident device 18 and adjusting the angle swing of the collimating light incident device 18 in the inner hole of the coupling pagoda sleeve 19, the surface of the light splitting reflector I5 is plated with a wavelength light splitting film 27, and the wavelength light splitting film 27 can transmit the light beam with the wavelength of 1512nm and then transmit the light beam to the photoelectric detector I15 through the light emergent hole I10 for ammonia measurement; the residual 1653nm and 1627nm composite light beams are reflected by the wavelength splitting film 27, and reach the splitting mirror II 6 after being reflected by the fixed mirror I2 and the fixed mirror II 3 for a plurality of times, the surface of the splitting mirror II 6 is plated with another wavelength splitting film 27, and the wavelength splitting film 27 can transmit 1653nm light beams to the photoelectric detector II 16 for medium methane measurement through the light exit hole II 11, so that the propagation path of the lower light path of the light beams is completed; finally, the remaining 1627nm light beam is reflected by the wavelength splitting film 27 on the surface of the splitting mirror II 6, reaches the light beam turning incident hole 22, reaches the turning mirror I7, passes through the light beam lifting hole 24 to the turning mirror II 8 after single total reflection, and passes through the light beam turning emergent hole 23 after single total reflection, thereby completing lifting and resculpting of the light beam path, namely, the propagation path tracks of the lower layer light path and the upper layer light path are consistent, but the propagation directions are opposite, and the layers are highly layered. The light beam with the wavelength of 1627nm after the re-etching sequentially passes through the fixed reflector III 4, the fixed reflector II 3 and the fixed reflector I2 for multiple reflections, and then enters the light emergent hole III 12 to reach the photoelectric detector III 17 for ethylene measurement.

The foregoing examples are merely illustrative of the present utility model and are not intended to limit the scope of the present utility model, and all designs that are the same or similar to the present utility model are within the scope of the present utility model.

Claims

1. The utility model provides a gas sensing is with reflection type air chamber, includes air chamber tube shell (1), its characterized in that: a fixed reflector I (2) is arranged on the inner wall of the front side of the air chamber tube shell (1); the left side and the right side of the fixed reflector I (2) are respectively provided with a light incident hole (9) and a light emergent hole II (11); the surface of the light emergent hole II (11) is covered with a light splitting reflector II (6); a fixed reflecting mirror III (4) is arranged above the light splitting reflecting mirror II (6); a fixed reflector II (3) parallel to the fixed reflector I (2) is arranged on the inner wall of the rear side of the air chamber tube shell (1); the left side and the right side of the fixed reflector II (3) are respectively provided with a light-emitting hole I (10) and a light beam lifting and rotating structure; the light emergent hole I (10) corresponds to the light incident hole (9); the surface of the light emergent hole I (10) is covered with a light-splitting reflector I (5); a light emergent hole III (12) is arranged above the light splitting reflector I (5); light entering from the light incidence hole (9) sequentially passes through the light splitting reflector I (5), the fixed reflector I (2), the fixed reflector II (3) and the light splitting reflector II (6) to form a lower layer zigzag light path; the light beam rising and turning structure receives light rays reflected by the light splitting reflector II (6), reflects the light rays to the upper fixed reflector III (4), forms an upper zigzag light path through the fixed reflector III (4), the fixed reflector II (3) and the fixed reflector I (2), and finally exits through the light exit hole III (12); the upper zigzag light path is parallel to the lower zigzag light path, and the propagation directions of the light beams are opposite.

2. The gas sensor reflective gas cell according to claim 1, wherein: the photoelectric detector is characterized by further comprising a photoelectric detector I (15), a photoelectric detector II (16) and a photoelectric detector III (17) which are arranged on the outer wall of the air chamber tube shell (1); the photoelectric detector I (15) is arranged at the light-emitting hole I (10); the photoelectric detector II (16) is arranged at the light-emitting hole II (11); the photodetector III (17) is mounted at the light exit aperture III (12).

3. The gas sensor reflective gas cell according to claim 1, wherein: a collimated light incident device (18) is arranged at the light incident hole (9).

4. A reflective gas cell for gas sensing according to claim 3, wherein: the device also comprises a coupling pagoda sleeve (19) and an inclined plane cylindrical boss (20) which is prefabricated on the outer wall of the air chamber tube shell (1); the collimated light incident device (18) passes through the coupling pagoda sleeve (19) and is fixed after coupling adjustment; the coupling pagoda sleeve (19) is fixed on the inclined plane cylindrical boss (20) after coupling adjustment; the light-entering hole (9) penetrates through the inclined plane cylindrical boss (20) and the air chamber tube shell (1).

5. A reflective gas cell for gas sensing according to claim 3, wherein: the collimated light incident device (18) is a passive fiber collimator or an active laser assembly with a collimating lens.

6. The gas sensor reflective gas cell according to claim 1, wherein: the beam lifting and turning structure comprises a beam turning bracket (21), and a turning reflector I (7) and a turning reflector II (8) which are fixed on the beam turning bracket (21); the beam turning support (21) is an isosceles trapezoid, and is internally provided with a beam turning inlet hole (22), a beam turning outlet hole (23) and a beam lifting hole (24); the bottom surface of the beam turning support (21) is fixed on the side wall of the air chamber tube shell (1), the beam turning inlet hole (22) penetrates through the side wall of the air chamber tube shell (1) and one side waist surface of an isosceles trapezoid of the beam turning support (21), the beam turning outlet hole (23) penetrates through the side wall of the air chamber tube shell (1) and the other side waist surface of the beam turning support (21), and the beam lifting hole (24) is communicated with the beam turning inlet hole (22) and the beam turning outlet hole (23); the turning reflector I (7) completely covers the beam turning incidence hole (22); the turning mirror II (8) completely covers the beam turning exit hole (23).

7. The gas sensor reflective gas cell according to claim 6, wherein: the fixed reflector I (2), the fixed reflector II (3), the fixed reflector III (4), the turning reflector I (7) and the turning reflector II (8) are plated with HR dielectric films (25).

8. The gas sensor reflective gas cell according to claim 1, wherein: the light splitting mirror I (5) and the light splitting mirror II (6) are plated with a light intensity splitting film (26) or a wavelength splitting film (27).

9. The gas sensor reflective gas cell according to claim 1, wherein: the air chamber tube shell (1) is sleeved with a diffusion type sealing cover (14), and a molecular filtering structure is arranged in the diffusion type sealing cover (14).

10. The gas sensor reflective gas cell according to claim 1, wherein: the inner wall of the air chamber tube shell (1) is also provided with a temperature pressure sensor (13), and the temperature pressure sensor (13) is close to the light emergent hole II (11).