Gas tank for gas detection, and assembly method and use method thereof
By introducing a reference adjustment mechanism into the gas detection gas tank, the central wavelength of the laser is automatically calibrated, which solves the problem that the gas tank measurement accuracy is affected by temperature, reducing costs and maintenance requirements.
Patent Information
- Application Number
- CN202411517495.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-29
- Publication Date
- 2024-12-27
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
The measurement accuracy of the gas tank is greatly affected by temperature, resulting in higher usage and maintenance costs.
A gas cell for gas detection is designed, including a reference adjustment mechanism, which detects the change in the center wavelength of the beam through the second light source incident assembly and the reference detector, adjusts the matching of the central wavelength of the laser with the absorption wavelength of the target test gas, and realizes the central wavelength of the laser Automatic calibration to avoid central wavelength drift caused by temperature changes.
It improves the measurement accuracy of the gas tank, reduces dependence on the constant temperature environment, and reduces the use and maintenance costs.
Smart Images
Figure CN119198568A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of gas detection, and in particular to a gas cell for gas detection and an assembly method and a use method thereof. Background Art
[0002] In the field of gas analysis, TDLAS technology is based on tunable diode lasers and uses the "frequency selection" characteristics of the gas molecules to measure the characteristics of the gas being measured. Based on the working principle of TDLAS, the gas cell can monitor the degree of light absorption by the gas in real time, thereby accurately determining the type and concentration of the gas. This is crucial for safety monitoring in industrial production processes, and can help companies promptly identify potential safety hazards and avoid accidents. The technology can also be applied to the field of environmental monitoring, providing strong support for air quality assessment, pollution source tracking, etc.
[0003] The gas cell is an indispensable optical component in the diffusion gas online measurement device. Currently, the measurement accuracy of the gas cell is greatly affected by temperature. The gas cell usually needs to be placed in a constant temperature environment, resulting in high usage and maintenance costs. Summary of the invention
[0004] The main purpose of the present invention is to provide a gas cell for gas detection and an assembly method and a use method, aiming to solve the problem that the measurement accuracy of the gas cell is greatly affected by temperature.
[0005] To achieve the above-mentioned purpose, the present invention proposes a gas cell for gas detection, including a gas cell body, the incident end of the gas cell body is provided with a first light source incident component for receiving a light beam emitted by a laser, the exit end of the gas cell body is provided with a detection detector, and is characterized in that it also includes a reference adjustment mechanism, the reference adjustment mechanism includes a second light source incident component, a reference gas chamber for filling a reference gas identical to a target test gas, a reference detector and an adjustment component for adjusting the central wavelength of the laser, the second light source incident component is arranged at the light input port of the reference gas chamber, the reference detector is arranged at the light output port of the reference gas chamber, the first light source incident component and the second light source incident component are both connected to the light output port of the laser, and the reference detector is interlocked with the adjustment component.
[0006] According to some embodiments of the present invention, the gas pool body includes a shell and a first reflector and a second reflector connected to the shell. The first reflector and the second reflector are arranged relative to each other with an interval and the opposite end faces are reflective surfaces.
[0007] According to some embodiments of the present invention, the first reflector is provided with a light entrance hole for the light beam received by the first light source incident component to pass through, and the second reflector is provided with a light exit hole for the outgoing light beam to pass through and enter the detection detector.
[0008] According to some embodiments of the present invention, a light entrance channel is formed on the shell between the light entrance hole and the first light source incident component, and a first sealing mirror is provided in the light entrance channel. A light exit channel is formed on the shell between the light exit hole and the detection detector, and a first sealing mirror is also provided in the light exit channel.
[0009] According to some embodiments of the present invention, the first reflector is provided with a plurality of light entrance holes, and the second reflector is provided with a plurality of light exit holes, the number of the light entrance holes and the light exit holes are the same and correspond one to one, each of the light entrance holes is configured with a first light source incident component, and each of the light exit holes is configured with a detection detector, wherein the first light source incident component and the second light source incident component are connected to the light outlet of the laser.
[0010] According to some embodiments of the present invention, the light entrance holes are arranged along the radial direction of the first reflector, and the light exit holes are arranged along the radial direction of the second reflector.
[0011] According to some embodiments of the present invention, the shell includes a first end plate and a second end plate that are relatively spaced apart, the first lens is installed on a side of the first end plate close to the second end plate, the second lens is installed on a side of the second end plate close to the first end plate, and a support column is connected between the first end plate and the second end plate.
[0012] According to some embodiments of the present invention, a second sealing mirror is provided at both the light entrance and the light exit of the reference air chamber.
[0013] According to some embodiments of the present invention, a plurality of lasers are further included, and the light outlet of each of the lasers is connected to the first light source incident component.
[0014] The present invention also provides an assembly method of the above-mentioned gas cell for gas detection, wherein the gas cell body comprises a shell, a first reflector, and a second reflector, and the shell comprises a support column, a support column locking mechanism, a first end plate, and a second end plate; the assembly method comprises the following steps:
[0015] S1: pre-fixing the first reflector on the first end plate, and fixing one end of the support column to the side of the first end plate where the first reflector is installed;
[0016] S2: pre-fixing the second reflector on the second end plate, and connecting the other end of the support column to the side of the second end plate on which the second reflector is installed through a support column locking mechanism;
[0017] S3: Adjust the locking mechanism of the support column so that the coaxiality and parallelism of the first reflector and the second reflector meet the preset requirements;
[0018] S4: adjusting the support column locking mechanism and coupling the first reflector and the second reflector through the laser indicator light source, and locking the support column locking mechanism after confirming that the reflected light path is correct;
[0019] S5: installing the first light source incident component at a corresponding position of the first end plate, and installing the detector detector at a corresponding position of the second end plate;
[0020] S6: pre-couple the first light source incident component and the detector, and after confirming that the coupling reaches the target value, fix the support column locking mechanism to the second end plate;
[0021] S7: pre-couple the first light source incident component and the detector detector again, and after confirming that the coupling reaches the target value, fix the detector detector to the second end plate;
[0022] S8: fixing the first reflector to the first end plate, and fixing the second reflector to the second end plate;
[0023] S9: Pre-couple the first light source incident component and the detector, and after confirming that the coupling reaches the target value, fix the first light source incident component to the first end plate, and fine-tune the first light source incident component to an optimal incident angle by asymmetric laser welding;
[0024] S10: installing the reference air chamber at a corresponding position on the housing, installing the second light source incident component at the light entrance of the reference air chamber, and installing the reference detector at the light exit of the reference air chamber;
[0025] S11: Pre-couple the second light source incident component and the reference detector, and after confirming that the coupling reaches the target value, fix the second light source incident component to the light input port, and use asymmetric laser welding to fine-tune the second light source incident component to the optimal incident angle, and fix the reference detector to the light output port.
[0026] The present invention also provides a method for using the above-mentioned gas detection gas cell, comprising the following steps:
[0027] Fill the gas pool with the target test gas, connect the first light source incident component and the second light source incident component to the light outlet of the laser, and then start the laser to emit a light beam;
[0028] According to the change of the central wavelength of the light beam detected by the reference detector, the central wavelength of the laser is matched with the absorption wavelength of the target test gas by adjusting the components;
[0029] The concentration of the target test gas is obtained according to the detection parameters of the light beam detected by the detection detector.
[0030] The present invention has at least the following beneficial effects:
[0031] In the present invention, the incident end of the gas pool body is provided with a first light source incident component for receiving the light beam emitted by the laser, and the exit end of the gas pool body is provided with a detector detector. The first light source incident component can be connected with the light outlet of the laser, and the light beam is emitted by starting the laser. The light beam passes through the gas pool and is received by the detector detector. The target test gas in the gas pool absorbs the light beam, and the detector detector detects the change in the absorption degree of the light intensity of the received light beam, thereby obtaining the concentration of the target test gas. It is worth mentioning that the present invention also includes a reference adjustment mechanism, which includes a second light source incident component, a reference gas chamber for filling a reference gas that is the same as the target test gas, a reference detector, and an adjustment component for adjusting the central wavelength of the laser. The second light source incident component is arranged at the light entrance of the reference gas chamber, and the reference detector is arranged at the light exit of the reference gas chamber. The first light source incident component and the second light source incident component are both connected with the light outlet of the laser, and the reference detector is interlocked with the adjustment component. Since the first light source incident component and the second light source incident component are both connected to the light outlet of the laser, the light beams received by the first light source incident component and the second light source incident component have the same source, and the light beam received by the second light source incident component passes through the reference gas in the reference gas chamber and then is emitted to the reference detector. The reference detector can detect the change in the central wavelength of the light beam, and according to the change in the central wavelength, the central wavelength of the laser is matched with the absorption wavelength of the target test gas by adjusting the component, so that the central wavelength of the light beam emitted by the laser is kept aligned with the absorption wavelength of the target gas to be measured in real time, thereby realizing automatic calibration of the central wavelength of the laser, avoiding the problem that the central wavelength of the laser cannot be aligned with the absorption wavelength of the target gas to be measured due to the drift of the central wavelength caused by the temperature change of the external environment, and thus solving the problem that the measurement accuracy of the gas cell is greatly affected by temperature. BRIEF DESCRIPTION OF THE DRAWINGS
[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0033] Figure 1 A schematic diagram of the structure of a gas cell for gas detection provided by an embodiment of the present invention;
[0034] Figure 2 for Figure 1 Schematic diagram of the structure inside the gas pool;
[0035] Figure 3 for Figure 1 A schematic cross-sectional view of the incident end of the gas pool body;
[0036] Figure 4 for Figure 1 A schematic cross-sectional view of the outlet end of the gas pool body;
[0037] Figure 5 A schematic cross-sectional view of the incident end of another gas cell for gas detection provided by an embodiment of the present invention;
[0038] Figure 6 A schematic cross-sectional view of an output end of another gas cell for gas detection provided in an embodiment of the present invention.
[0039] Description of reference numerals:
[0040] 100-gas pool; 1-gas pool body; 11-incident end; 12-exit end; 13-shell; 131-first end plate; 132-second end plate; 133-light entrance channel; 134-light exit channel; 135-support column; 136-support column locking mechanism; 14-first sealing mirror; 15-sealing cover; 2-first reflecting mirror; 21-light entrance hole; 3-second reflecting mirror; 31-light exit hole; 41-first light source incident component; 42-second light source incident component; 43-light source incident component adjusting sleeve; 5-detection detector; 51-detection detector adjusting sleeve; 6-reference gas chamber; 61-light entrance port; 62-light exit port; 63-second sealing mirror; 7-reference detector; 71-reference detector adjusting sleeve. DETAILED DESCRIPTION
[0041] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0042] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.
[0043] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in the field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.
[0044] The present invention provides a gas cell for gas detection. Figure 1-Figure 6 A specific embodiment of a gas cell for gas detection provided by the present invention.
[0045] like Figure 1-4 The embodiment of the present invention provides a gas cell 100 for gas detection, including a gas cell body 1, wherein the incident end 11 of the gas cell body 1 is provided with a first light source incident component 41 for receiving a light beam emitted by a laser, the exit end 12 of the gas cell body 1 is provided with a detector detector 5, and also includes a reference adjustment mechanism, wherein the reference adjustment mechanism includes a second light source incident component 42, a reference gas chamber 6 for filling a reference gas identical to a target test gas, a reference detector 7, and an adjustment component for adjusting the central wavelength of the laser, wherein the second light source incident component 42 is provided at a light inlet 61 of the reference gas chamber 6, and the reference detector 7 is provided at a light outlet 62 of the reference gas chamber 6, the first light source incident component 41 and the second light source incident component 42 are both connected to the light outlet 62 of the laser, and the reference detector 7 is interlocked with the adjustment component.
[0046] In the present invention, the incident end 11 of the gas pool body 1 is provided with a first light source incident component 41 for receiving a light beam emitted by a laser, and the exit end 12 of the gas pool body 1 is provided with a detection detector 5. The first light source incident component 41 can be connected with the light outlet 62 of the laser. By starting the laser to emit a light beam, the light beam passes through the gas pool 100 and is received by the detection detector 5. The target test gas in the gas pool 100 absorbs the light beam, and the detection detector 5 detects the change in the light intensity absorption degree of the received light beam, thereby obtaining the concentration of the target test gas. It is worth mentioning that the present invention also includes a reference adjustment mechanism, which includes a second light source incident component 42, a reference gas chamber 6 for filling a reference gas identical to the target test gas, a reference detector 7 and an adjustment component for adjusting the central wavelength of the laser, the second light source incident component 42 is arranged at the light inlet 61 of the reference gas chamber 6, the reference detector 7 is arranged at the light outlet 62 of the reference gas chamber 6, the first light source incident component 41 and the second light source incident component 42 are both connected to the light outlet 62 of the laser, and the reference detector 7 is interlocked with the adjustment component. Since the first light source incident component 41 and the second light source incident component 42 are both connected to the light outlet 62 of the laser, the light beams received by the first light source incident component 41 and the second light source incident component 42 have the same source, and the light beam received by the second light source incident component 42 passes through the reference gas in the reference gas chamber 6 and then is emitted to the reference detector 7. The reference detector 7 can detect the change in the central wavelength of the light beam, and according to the change in the central wavelength, the central wavelength of the laser is matched with the absorption wavelength of the target test gas by adjusting the components, so that the central wavelength of the light beam emitted by the laser is kept aligned with the absorption wavelength of the target gas to be measured in real time, thereby realizing automatic calibration of the central wavelength of the laser, avoiding the problem that the central wavelength of the laser cannot be aligned with the absorption wavelength of the target gas to be measured due to the drift of the central wavelength caused by the temperature change of the external environment, and thus solving the problem that the measurement accuracy of the gas pool 100 is greatly affected by temperature.
[0047] It should be noted that when the laser is affected by the ambient temperature, its central wavelength will drift. However, to achieve high-precision measurement of the laser, it is necessary to ensure that the central wavelength of the laser light source is exactly aligned with the absorption wavelength of the gas being measured. The reference adjustment mechanism provided in this application is used to make real-time adjustments to the drift changes of the central wavelength of the laser.
[0048] It is understandable that there is no specific limitation on the form in which the first light source incident component 41 and the second light source incident component 42 are connected to the light outlet 62 of the laser. In some embodiments, the first light source incident component 41 and the second light source incident component 42 are connected via a splitter mechanism.
[0049] The reference adjustment mechanism provided in the present application also includes a controller, which is used to obtain the detection signal of the reference detector 7 and control the adjustment component to adjust the central wavelength of the laser.
[0050] When in use, start the laser to emit a light beam. Since the first light source incident component 41 and the second light source incident component 42 are both connected to the light outlet 62 of the laser, the light beams received by the first light source incident component 41 and the second light source incident component 42 are of the same source. The first light source incident component 41 receives the test beam, and the second light source incident component 42 receives the reference beam. The test beam passes through the gas pool 100 and is received by the detector detector 5. The detector detector 5 detects the change in the degree of absorption of the light intensity of the measurement beam, thereby obtaining the concentration of the target test gas in the gas pool 100. The reference beam that is of the same source as the test beam is received by the reference detector 7. The reference detector 7 detects the change in the central wavelength of the reference beam, and matches the central wavelength of the laser with the absorption wavelength of the target test gas by adjusting the component, thereby keeping the central wavelength of the laser aligned with the absorption wavelength of the target test gas in real time.
[0051] In the traditional spectral analysis method, the number of interactions between light and matter is limited, and the absorption efficiency is often limited, which affects the accuracy of the measurement results to a certain extent. In some embodiments, the gas cell body 1 includes a shell 13 and a first reflector 2 and a second reflector 3 connected to the shell 13. The first reflector 2 and the second reflector 3 are arranged at a relative interval and the opposite end faces are reflective surfaces. The first reflector 2 and the second reflector 3 form a long optical path gas cell, which enables light to achieve controlled and regular multiple reflections in the gas cell 100, thereby significantly enhancing the number of interactions between light and the substance to be measured. Specifically, after the light beam received by the first light source incident component 41 enters the long optical path gas cell, the light beam can be reflected multiple times between the first reflector 2 and the second reflector 3 and then received by the detector 5, which effectively improves the absorption efficiency of light, makes the target test gas absorb light more fully, and greatly improves the measurement accuracy.
[0052] Furthermore, in some embodiments, the first reflector 2 is provided with a light entrance hole 21 for the light beam received by the first light source incident component 41 to pass through, and the second reflector 3 is provided with a light exit hole 31 for the outgoing light beam to pass through and be emitted into the detection detector 5. Through this arrangement, the use of additional optical elements to guide the light beam is avoided, thereby reducing the complexity and cost of the system. The light beam received by the first light source incident component 41 can directly enter the gas pool 100 through the light entrance hole 21, and then be emitted from the gas pool 100 through the light exit hole 31 and received by the detection detector 5. Moreover, by accurately designing the position and size of the light entrance hole 21 and the light exit hole 31, the number of reflections and thus the number of actions can be maximized, which is conducive to improving the measurement accuracy.
[0053] Specifically, in some embodiments, a light input channel 133 is formed on the shell 13 between the light input hole 21 and the first light source incident component 41, and a first sealing mirror 14 is provided in the light input channel 133. A light output channel 134 is formed on the shell 13 between the light output hole 31 and the detector 5, and a first sealing mirror 14 is also provided in the light output channel 134. By providing sealing mirrors in the light input channel 133 and the light output channel 134, the sealing effect of the gas pool 100 can be improved, the emission light path can be isolated from the external environment, and the measurement accuracy can be improved. The two first sealing mirrors 14 are respectively installed non-parallel to the first reflector 2 and the second reflector 3. Specifically, the first sealing mirror 14 is non-perpendicular to the main optical axis of the incident light beam, and is installed and fixed at a certain angle to avoid the occurrence of a light path that is reflected back and forth, which brings optical noise to the entire system.
[0054] Specifically, see Figure 5-6 In some embodiments, the first reflector 2 is provided with a plurality of light entrance holes 21, and the second reflector 3 is provided with a plurality of light exit holes 31. The number of the light entrance holes 21 and the light exit holes 31 is the same and corresponds to each other. Each of the light entrance holes 21 is provided with a first light source incident component 41, and each of the light exit holes 31 is provided with a detector 5, wherein the first light source incident component 41 and the second light source incident component 42 are connected to the light exit port 62 of the laser. Through this arrangement, it is possible to detect multiple gases simultaneously in a gas pool 100, which greatly improves the detection efficiency and also improves the utilization rate of the reflection area of the reflective lens.
[0055] Furthermore, in some embodiments, each of the light entrance holes 21 is arranged along the radial direction of the first reflector 2, and each of the light exit holes 31 is arranged along the radial direction of the second reflector 3. It should be noted that the standard reflection light path trajectory of the gas pool 100 provided in the present application is a circle, so by setting each group of light entrance holes 21 and light exit holes 31 at different diameters, the reflection light path trajectories formed by different light sources on the reflector will be concentric circles of different diameters, and the concentric circles of different diameters do not interfere with each other, thus avoiding light interference between different light sources, thereby reducing the influence between each group of light sources, and improving the reflection area utilization rate of the reflector lens while ensuring the measurement accuracy.
[0056] Specifically, in some embodiments, the housing 13 includes a first end plate 131 and a second end plate 132 that are relatively spaced apart, the first lens is installed on the side of the first end plate 131 close to the second end plate 132, the second lens is installed on the side of the second end plate 132 close to the first end plate 131, and a support column 135 is connected between the first end plate 131 and the second end plate 132. The two end plates on which the first reflector 2 and the second reflector 3 are installed are connected by the support column 135, which ensures that the position between the two reflectors is relatively fixed, and also connects the two end plates into a whole, thereby improving the structural stability of the gas pool 100, being able to resist deformation of various components of the gas chamber structure caused by changes in ambient temperature, thereby reducing the influence of temperature changes on measurement accuracy. It can be understood that the number of the support columns 135 is not limited, and is selected according to specific needs.
[0057] Specifically, in some embodiments, the reference air chamber 6 includes a sealing sleeve installed on the housing 13 .
[0058] Specifically, in some embodiments, the housing 13 further includes a sealing cover 15, and the housing 13 is contained in the sealing cover 15. The gas pool 100 can be sealed by the sealing cover 15 to isolate the external environment, so that the gas chamber structure is more stable. It is worth mentioning that after sealing to isolate the external environment, after cooperating with the support column 135 to further improve the structural stability of the gas chamber, it is possible to work in a constant temperature environment without setting a heat preservation structure, thereby reducing the influence of temperature changes on the measurement accuracy.
[0059] Specifically, in some embodiments, the light inlet 61 and the light outlet 62 of the reference gas chamber 6 are both provided with a second sealing mirror 63 , and the light inlet 61 and the light outlet 62 are sealed by the second sealing mirror 63 to improve the measurement accuracy of the reference detector 7 .
[0060] Specifically, in some embodiments, a support column locking mechanism 136 is also included, one end of the support column 135 is fixedly connected to the first end plate 131, and the other end of the support column 135 is connected to the second end plate 132 through the support column locking mechanism 136. When the support column locking mechanism 136 is in an unlocked state, the relative position of the second end plate 132 and the support column 135 can be adjusted, thereby adjusting the parallelism and coaxiality of the first reflector 2 and the second reflector 3. After the adjustment is completed, the support column locking mechanism 136 is locked.
[0061] Specifically, in order to facilitate the XYZ three-dimensional coupling adjustment when the first light source incident component 41, the second light source incident component 42, the reference detector 7, and the detection detector 5 are installed in the corresponding installation holes on the shell 13, in some embodiments, a light source incident component adjustment sleeve 43 for XYZ three-dimensional coupling adjustment, a detection detector adjustment sleeve 51 for XYZ three-dimensional coupling adjustment, and a reference detector adjustment sleeve 71 for XYZ three-dimensional coupling adjustment are also configured. The first light source incident component 41 is coupled and installed on the gas pool body 1 through the light source incident component adjustment sleeve 43, the second light source incident component 42 is coupled and installed on the light inlet 61 through the light source incident component adjustment sleeve 43, the detection detector 5 is coupled and installed on the gas pool body 1 through the detection detector adjustment sleeve 51, and the reference detector 7 is coupled and installed on the light outlet 62 through the reference detector adjustment sleeve 71. By adjusting the sleeve, the first light source incident component 41, the second light source incident component 42, the reference detector 7, and the detection detector 5 can be coupled and adjusted separately during the installation process, thereby decomposing the manufacturing process of the gas pool 100, reducing the difficulty of the overall manufacturing process, and solving the problems of complex coupling methods of the components in the gas pool 100, complex manufacturing process, poor manufacturability, and high manufacturing cost.
[0062] It should be noted that after the coupling installation is completed, the first light source incident component 41, the second light source incident component 42, the reference detector 7, and the detection detector 5 can be fixedly connected by gluing or laser welding or a combination of the above two methods to further improve the structural stability of the gas pool 100.
[0063] Specifically, in some embodiments, multiple lasers are also included, and the light outlet 62 of each of the lasers is connected to the first light source incident component 41. It should be noted that the central wavelength of each laser is different. By selecting different lasers to emit light beams to the first light source incident component 41, different target test gases in the gas pool 100 can be tested.
[0064] Specifically, in some embodiments, the reflective surfaces of the first reflector 2 and the second reflector 3 are coated with a metal reflective film and / or a HR dielectric film to increase the reflectivity of the light beam. In addition, the HR dielectric film can be optimized for a specific wavelength to achieve a higher reflectivity and can be selected according to the absorption wavelength of the target test gas to improve the reflectivity of the light beam whose central wavelength emitted by the laser is the same as the absorption wavelength of the target test gas.
[0065] The present application also provides an assembly method of the above-mentioned gas cell 100 for gas detection, wherein the gas cell body 1 includes a shell 13, a first reflector 2, and a second reflector 3, and the shell 13 includes a support column 135, a support column locking mechanism 136, a first end plate 131, and a second end plate 132; the method includes the following steps:
[0066] S1: pre-fix the first reflector 2 on the first end plate 131, and fix one end of the support column 135 to the side of the first end plate 131 where the first reflector 2 is installed;
[0067] S2: pre-fix the second reflector 3 on the second end plate 132, and connect the other end of the support column 135 to the side of the second end plate 132 where the second reflector 3 is installed through the support column locking mechanism 136;
[0068] It should be noted that the first reflector 2 and the second reflector 3 can be pre-fixed by UV glue.
[0069] S3: Adjust the support column locking mechanism 136 so that the coaxiality and parallelism of the first reflector 2 and the second reflector 3 meet the preset requirements;
[0070] It should be noted that, when the support column locking mechanism 136 is unlocked, the relative position of the second end plate 132 and the support column 135 is adjusted to adjust the parallelism and coaxiality of the first reflector 2 and the second reflector 3 to meet the requirements, and then the support column locking mechanism 136 is locked. The specific method of the support column locking mechanism 136 is not limited, and it only needs to be able to limit the relative movement of the second end plate 132 and the support column 135. For example, one end of the support column 135 connected to the second end plate 132 passes through the second end plate 132, and two nuts are screwed on the support column 135, and the two nuts are respectively located at opposite ends of the second end plate to lock the support column and the second end plate.
[0071] S4: adjusting the support column locking mechanism 136 and coupling the first reflector 2 and the second reflector 3 through the laser indicator light source, and after confirming that the reflected light path is correct, locking the support column locking mechanism 136;
[0072] S5: Install the first light source incident component 41 at a corresponding position of the first end plate 131, and install the detection detector 5 at a corresponding position of the second end plate 132;
[0073] It should be noted that the first end plate 131 is provided with a first light source incident component mounting hole, and the second end plate 132 is provided with a detection detector mounting hole. The first light source incident component 131 is installed on the first light source incident component mounting hole, and the detection detector 5 is installed on the detection detector mounting hole.
[0074] S6: Pre-couple the first light source incident component 41 and the detection detector 5, and after confirming that the coupling reaches the target value, fix the support column locking mechanism 136 to the second end plate;
[0075] It should be noted that the fixed connection method is not specifically limited and may be glue bonding and / or laser welding.
[0076] S7: Pre-couple the first light source incident component 41 and the detector detector 5 again, and after confirming that the coupling reaches the target value, fix the detector detector 5 to the second end plate 132;
[0077] It should be noted that the fixed connection method is not specifically limited and may be glue bonding and / or laser welding.
[0078] S8: The first reflector 2 is fixedly connected to the first end plate 131, and the second reflector 3 is fixedly connected to the second end plate 132;
[0079] It should be noted that, in some embodiments, the first reflector 2 is fixed to the first end plate 132 and the second reflector 3 is fixed to the second end plate 132 by curing glue, and the glue dot positions should be evenly distributed at multiple points, usually three-point evenly distributed, four-point evenly distributed, or multi-point symmetrical glue dot position distribution is adopted. Under the premise of ensuring strength, the glue dot amount should be reduced as much as possible, and the glue amount at each glue dot position should be kept as consistent as possible.
[0080] S9: Pre-couple the first light source incident component 41 and the detection detector 5. After confirming that the coupling reaches the target value, the first light source incident component 41 is fixedly connected to the first end plate 131, and the first light source incident component 41 is fine-tuned to the optimal incident angle by asymmetric laser welding;
[0081] It should be noted that there is no specific restriction on the method of fixed connection, which may be glue bonding and / or laser welding. When laser welding is used, it is considered that there will be certain welding deformation at the weld of the first light source incident component 41 after welding, which affects the structural stability and coupling effect. Preferably, the step of fixedly connecting the first light source incident component 41 to the first end plate 131 includes: preliminarily welding the first light source incident component 41 to the first end plate 131 by laser welding equipment, and then repairing the welding connection between the first light source incident component 41 and the first end plate 131 by asymmetric laser welding to ensure that the coupling is adjusted to the target value.
[0082] The positions of the first light source incident component 41 and the first end plate 131 can be relatively fixed by preliminary welding, and then corresponding repair welding adjustments are performed according to the coupling conditions of the relative positions by using non-symmetrical welding. This not only enhances the quality of the weld to improve the structural stability, but also fine-tunes the first light source incident component 41 to the optimal incident angle, thereby improving the coupling effect of the first light source incident component 41.
[0083] S10: Install the reference gas chamber 6 at a corresponding position on the housing 13, install the second light source incident assembly 42 at the light entrance 61 of the reference gas chamber 6, and install the reference detector 7 at the light exit 62 of the reference gas chamber 6;
[0084] It should be noted that the specific form of the reference air chamber 6 is not limited, and it can be a sealed cavity. For example, in this embodiment, the reference air chamber 6 includes a sealed sleeve.
[0085] S11: Pre-couple the second light source incident component 42 and the reference detector 7, and after confirming that the coupling has reached the target value, fix the second light source incident component 42 to the light input port 61, and use asymmetric laser welding to fine-tune the second light source incident component 42 to the optimal incident angle, and fix the reference detector to the light output port 62.
[0086] It should be noted that there is no specific limitation on the method of fixed connection, which may be glue bonding and / or laser welding. When laser welding is used, considering that the second light source incident component 42 may have certain welding deformation at the weld after welding, which may affect the structural stability and coupling effect, preferably, the step of fixedly connecting the second light source incident component 42 to the light entrance 61 includes: preliminarily welding the second light source incident component 42 to the light entrance 61 by laser welding equipment, and then repairing the second light source incident component 42 by asymmetric laser welding to ensure that the coupling is adjusted to the target value.
[0087] The positions of the second light source incident component 42 and the light entrance port 61 can be relatively fixed by preliminary welding, and then corresponding repair welding adjustments are performed according to the coupling conditions of the relative positions. This not only enhances the quality of the weld to improve structural stability, but also fine-tunes the second light source incident component 42 to the optimal incident angle, thereby improving the coupling effect of the second light source incident component 42.
[0088] The present application also provides a method for using the above-mentioned gas detection gas cell 100, comprising the following steps:
[0089] S1: Fill the gas pool 100 with the target test gas, connect the first light source incident component 41 and the second light source incident component 42 to the light outlet 62 of the laser, and then start the laser to emit a light beam;
[0090] Specifically, since the first light source incident component 41 and the second light source incident component 42 are both connected to the light outlet 62 of the laser, it is ensured that the first light source incident component 41 and the second light source incident component 42 receive the same light beam. In addition, when in use, the reference gas chamber 6 is also filled with a reference gas that is the same as the target test gas. It should be noted that the detection wavelength of the selected laser emission needs to match the absorption wavelength of the target test gas.
[0091] S2: According to the change of the central wavelength of the light beam detected by the reference detector 7, the central wavelength of the laser is matched with the absorption wavelength of the target test gas by adjusting the components;
[0092] It is understandable that when the laser is used for a long time or is affected by the change of ambient temperature, its central wavelength will drift. Therefore, the reference detector 7 can detect the change of the central wavelength of the reference beam, so as to match the central wavelength of the laser with the absorption wavelength of the target test gas through the adjustment component. The matching can be that the adjustment component makes the central wavelength of the laser consistent with or close to the absorption wavelength of the target test gas. Specifically, the reference detector 7 detects the change of the central wavelength of the reference beam, and the controller obtains the detection signal of the reference detector 7 and controls the adjustment component to adjust the central wavelength of the laser, so that the central wavelength of the laser output beam is kept aligned with the central wavelength of the target gas to be measured in real time. The adjustment component can be a temperature control device for controlling the temperature of the laser or a current adjustment device for adjusting the driving current. For example, when the central wavelength of the laser emission beam moves in the direction of the wavelength becoming longer, the laser temperature can be reduced by the temperature control device to pull the wavelength back, otherwise the laser temperature can be increased to pull the wavelength back, so that the central wavelength of the laser emission beam is kept aligned with the absorption wavelength of the target gas to be measured in real time, thereby avoiding the problem of reduced measurement accuracy caused by the drift of the central wavelength of the laser due to the influence of the external temperature environment.
[0093] S3: Acquire the concentration of the target test gas according to the detection parameters of the light beam detected by the detection detector 5.
[0094] It is understandable that the detector 5 can obtain the concentration of the target test gas by detecting the change in the absorption degree of the light intensity of the received light beam. It should be noted that the order of the above steps S2 and S3 is not limited and can be performed simultaneously. The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. A gas cell for gas detection, comprising a gas cell body, wherein the incident end of the gas cell body is provided with a first light source incident component for receiving a laser light beam, and the exit end of the gas cell body is provided with a detector, characterized in that: It also includes a reference adjustment mechanism, which includes a second light source incident component, a reference gas chamber for filling with a reference gas that is the same as the target test gas, a reference detector, and an adjustment component for adjusting the central wavelength of the laser. The second light source incident component is arranged at the light inlet of the reference gas chamber, and the reference detector is arranged at the light outlet of the reference gas chamber. The first light source incident component and the second light source incident component are both connected to the light outlet of the laser, and the reference detector is interlocked with the adjustment component.
2. The gas cell for gas detection according to claim 1, characterized in that: The gas pool body comprises a shell, and a first reflector and a second reflector connected to the shell. The first reflector and the second reflector are arranged opposite to each other with an interval, and the opposite end faces are reflective surfaces.
3. The gas cell for gas detection as claimed in claim 2, characterized in that: The first reflector is provided with a light entrance hole for the light beam received by the first light source incident component to pass through, and the second reflector is provided with a light exit hole for the outgoing light beam to pass through and enter the detector.
4. The gas cell for gas detection as described in claim 3, has a light input channel formed on the shell between the light input hole and the first light source incident component, a first sealing mirror is provided in the light input channel, and a light output channel is formed on the shell between the light output hole and the detection detector, a first sealing mirror is also provided in the light output channel.
5. The gas cell for gas detection as claimed in claim 3, characterized in that: The first reflector is provided with a plurality of light entrance holes, and the second reflector is provided with a plurality of light exit holes, the number of the light entrance holes and the light exit holes are the same and correspond one to one, each of the light entrance holes is configured with a first light source incident component, and each of the light exit holes is configured with a detection detector, wherein the first light source incident component and the second light source incident component are connected to the light outlet of the laser.
6. The gas cell for gas detection as claimed in claim 5, characterized in that: The light entrance holes are arranged along the radial direction of the first reflector, and the light exit holes are arranged along the radial direction of the second reflector.
7. The gas cell for gas detection according to claim 2, characterized in that: The shell includes a first end plate and a second end plate that are relatively spaced apart. The first lens is installed on a side of the first end plate close to the second end plate, and the second lens is installed on a side of the second end plate close to the first end plate. A support column is connected between the first end plate and the second end plate.
8. The gas cell for gas detection according to claim 1, characterized in that: The light inlet and light outlet of the reference air chamber are both provided with a second sealing mirror.
9. The method for assembling a gas cell for gas detection according to any one of claims 1 to 8, characterized in that: The gas pool body comprises a shell, a first reflector, and a second reflector. The shell comprises a support column, a support column locking mechanism, a first end plate, and a second end plate. The assembly method comprises the following steps: S1: pre-fixing the first reflector on the first end plate, and fixing one end of the support column to the side of the first end plate where the first reflector is installed; S2: pre-fixing the second reflector on the second end plate, and connecting the other end of the support column to the side of the second end plate on which the second reflector is installed through a support column locking mechanism; S3: Adjust the locking mechanism of the support column so that the coaxiality and parallelism of the first reflector and the second reflector meet the preset requirements; S4: adjusting the support column locking mechanism and coupling the first reflector and the second reflector through the laser indicator light source, and locking the support column locking mechanism after confirming that the reflected light path is correct; S5: installing the first light source incident component at a corresponding position of the first end plate, and installing the detector detector at a corresponding position of the second end plate; S6: pre-couple the first light source incident component and the detector, and after confirming that the coupling reaches the target value, fix the support column locking mechanism to the second end plate; S7: pre-couple the first light source incident component and the detector detector again, and after confirming that the coupling reaches the target value, fix the detector detector to the second end plate; S8: fixing the first reflector to the first end plate, and fixing the second reflector to the second end plate; S9: Pre-couple the first light source incident component and the detector, and after confirming that the coupling reaches the target value, fix the first light source incident component to the first end plate, and fine-tune the first light source incident component to an optimal incident angle by asymmetric laser welding; S10: installing the reference air chamber at a corresponding position on the housing, installing the second light source incident component at the light entrance of the reference air chamber, and installing the reference detector at the light exit of the reference air chamber; S11: Pre-couple the second light source incident component and the reference detector, and after confirming that the coupling reaches the target value, fix the second light source incident component to the light input port, and use asymmetric laser welding to fine-tune the second light source incident component to the optimal incident angle, and fix the reference detector to the light output port.
10. The method for using the gas cell for gas detection according to any one of claims 1 to 8, characterized in that: The following steps are involved: Fill the gas pool with the target test gas, connect the first light source incident component and the second light source incident component to the light outlet of the laser, and then start the laser to emit a light beam; According to the change of the central wavelength of the light beam detected by the reference detector, the central wavelength of the laser is matched with the absorption wavelength of the target test gas by adjusting the components; The concentration of the target test gas is obtained according to the detection parameters of the light beam detected by the detection detector.