Calibration device of laser gas sensor

Abstract

The utility model discloses a calibration device of a laser gas sensor, and relates to the technical field of gas sensor calibration, the laser gas sensor is provided with a mounting groove, the side wall of the mounting groove is provided with a laser emitter and a laser detector which are oppositely arranged, the laser detector is used for receiving laser beams emitted by the laser emitter, and the laser beams are arranged on the mounting groove. The calibration device comprises a box body, a sealing cavity is formed in the box body, the sealing cavity is suitable for storing gas, the side wall of the sealing cavity is further provided with a light-transmitting part, and at least part of the box body is suitable for being installed in the installation groove so that the light-transmitting part can be located between the laser transmitter and the laser detector. Therefore, multi-concentration-point calibration of the laser gas sensor can be realized by replacing the calibration device with the calibration gases with different concentrations, the calibration process is simplified, and meanwhile, the manufacturing cost of the laser gas sensor is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of gas sensor calibration, in particular to a calibration device for a laser gas sensor. Background Art

[0002] Laser gas sensors based on tunable diode laser absorption spectroscopy technology are widely used in the fields of urban public safety, energy, electric power, materials, electronic technology, etc.

[0003] In related technologies, a laser gas sensor needs to be calibrated for concentration before leaving the factory. The traditional calibration method is to place the laser gas sensor inside a calibration tooling, and then introduce standard gases with different known concentrations into the calibration tooling for calibration. However, in the traditional calibration method, the gas path connection method, the insertion and removal of the gas path, and the instability of the ventilation state will all affect the calibration result, resulting in a large calibration error. Moreover, the standard gas cannot be recycled during the calibration process, thus causing waste of the standard gas and increasing the manufacturing cost of the laser gas sensor. Summary of the Utility Model

[0004] The utility model aims to at least solve one of the technical problems existing in the prior art. For this reason, the purpose of the utility model is to provide a calibration device for a laser gas sensor. By replacing the calibration device with calibration gases of different concentrations, multi-concentration point calibration of the laser gas sensor can be achieved, which simplifies the calibration process, reduces the influence of the gas path connection method, the insertion and removal of the gas path, and the instability of the ventilation state on the calibration result in the traditional calibration method, improves the calibration accuracy. At the same time, the calibration device can be reused repeatedly, which is beneficial to reducing the manufacturing cost of the laser gas sensor.

[0005] To achieve the above object, an embodiment of the utility model provides a calibration device for a laser gas sensor. The laser gas sensor has an installation groove, and the side wall of the installation groove has a laser emitter and a laser detector arranged oppositely. The laser detector is used to receive the laser beam emitted by the laser emitter. The calibration device includes:

[0006] A box body, which has a sealed cavity inside. The sealed cavity is suitable for storing gas. The side wall of the sealed cavity also has a light-transmitting part. At least part of the box body is suitable for being installed in the installation groove so that the light-transmitting part is located between the laser emitter and the laser detector.

[0007] According to the calibration device of the embodiment of the present utility model, a calibration gas with a certain concentration is pre-stored in the sealed cavity of the calibration device. When the laser gas sensor needs to be calibrated for concentration, the calibration device is installed in the optical path system of the laser gas sensor, so that the light-transmitting part of the calibration device is located between the laser emitter and the laser detector, so that the laser beam emitted by the laser emitter can enter the laser detector after passing through the calibration gas in the sealed cavity, and then the concentration calibration is completed by using the laser detector. Thus, by replacing the calibration device with calibration gases of different concentrations, multi-concentration point calibration of the laser gas sensor can be realized, the calibration process is simplified, and the influence of the gas path connection method, the insertion and removal of the gas path, and the unstable ventilation state on the calibration result in the traditional calibration method is reduced, the calibration accuracy is improved. At the same time, the calibration device can be reused repeatedly, which is beneficial to reducing the manufacturing cost of the laser gas sensor.

[0008] According to an embodiment of the present utility model, the box body further has a first light-transmitting part and a second light-transmitting part which are oppositely arranged. The first light-transmitting part and the second light-transmitting part are the side walls of the sealed cavity. At least part of the box body is adapted to be installed in the installation groove, so that the first light-transmitting part is opposite to the laser emitter and the second light-transmitting part is opposite to the laser detector.

[0009] According to an embodiment of the present utility model, the box body includes:

[0010] A cover plate and a base. The base has a gas groove, and the cover plate is used to seal the gas groove so as to be adapted to jointly define a sealed cavity with the base.

[0011] According to an embodiment of the present utility model, the first light-transmitting part and the second light-transmitting part are the side walls of the gas groove. At least part of the base is adapted to be installed in the installation groove, so that the first light-transmitting part is opposite to the laser emitter and the second light-transmitting part is opposite to the laser detector.

[0012] According to an embodiment of the present utility model, the first light-transmitting part is configured as a first light-transmitting plate, and the first light-transmitting plate has a first included angle α with the bottom wall of the gas groove, satisfying the relational expression: 30° ≤ α ≤ 60°;

[0013] The second light-transmitting part is configured as a second light-transmitting plate, and the second light-transmitting plate has a second included angle β with the bottom wall of the gas groove, satisfying the relational expression: 30° ≤ β ≤ 60°.

[0014] According to an embodiment of the present utility model, the material of the base is an acrylic plate.

[0015] According to an embodiment of the present utility model, the box body further includes: a sealing member. The base further has a sealing groove surrounding the opening of the gas groove, and the sealing member is arranged in the sealing groove.

[0016] Additional aspects and advantages of the present utility model will be given in part in the following description, become apparent in part from the following description, or be understood through the practice of the present utility model. Description of the Drawings

[0017] Figure 1 Exploded view of a calibration device according to an embodiment of the present utility model;

[0018] Figure 2 Schematic diagram of a calibration device and a laser gas sensor according to an embodiment of the present utility model;

[0019] Figure 3 Assembly drawing of a calibration device and a laser gas sensor according to an embodiment of the present utility model;

[0020] Figure 4 Assembly sectional view of a calibration device and a laser gas sensor according to an embodiment of the present utility model.

[0021] Reference numerals:

[0022] Calibration device 100;

[0023] Box body 1; Sealing cavity 11; First light-transmitting part 12; Second light-transmitting part 13; Cover plate 14; Base 15; Gas groove 151; Sealing groove 152;

[0024] Sealing member 2;

[0025] Fastener 3;

[0026] Laser gas sensor 200; Installation groove 201; Laser emitter 202; Laser detector 203. Detailed Description of the Embodiment

[0027] Embodiments of the present utility model will be described in detail below. Examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present utility model and should not be construed as limiting the present utility model.

[0028] It should be noted that laser gas sensors based on tunable diode laser absorption spectroscopy technology are widely used in fields such as urban public safety, energy, power, materials, and electronic technology.

[0029] In the related art, before leaving the factory, a laser gas sensor needs to be calibrated for concentration. The traditional calibration method is to place the laser gas sensor inside a calibration tooling, and then introduce standard gases with different known concentrations into the calibration tooling for calibration. However, in the traditional calibration method, the gas path connection method, the insertion and removal of the gas path, and the unstable ventilation state will all affect the calibration result, resulting in a large calibration error. Moreover, during the calibration process, the standard gas cannot be recycled, thus causing waste of the standard gas and increasing the manufacturing cost of the laser gas sensor.

[0030] Based on this, the present application proposes a calibration device 100 for a laser gas sensor 200. When it is necessary to calibrate the concentration of the laser gas sensor 200, by replacing the calibration device 100 with calibration gases of different concentrations, multi-concentration point calibration of the laser gas sensor 200 can be achieved, simplifying the calibration process and reducing the influence of the gas path connection method, the insertion and removal of the gas path, and the unstable ventilation state in the traditional calibration method on the calibration result, improving the calibration accuracy. At the same time, the calibration device 100 can be reused repeatedly, which is beneficial to reducing the manufacturing cost of the laser gas sensor 200.

[0031] It should be noted that the calibration device 100 in the present application is used in cooperation with the laser gas sensor 200. Specifically, as Figure 2 and Figure 4 shown, the laser gas sensor 200 is provided with an installation groove 201 with one end open. The side wall of the installation groove 201 has a laser emitter 202 and a laser detector 203 arranged oppositely. The laser emitter 202 and the laser detector 203 together form an optical path system. The laser detector 203 is used to receive the laser beam emitted by the laser emitter 202. It can be understood that the laser emitter 202 and the laser detector 203 are at the same horizontal height, and the laser emitter 202 emits a horizontal laser beam towards the laser detector 203.

[0032] Furthermore, as Figures 1 - 4 shown, the calibration device 100 for the laser gas sensor 200 according to the first aspect embodiment of the present utility model includes: a box body 1. The box body 1 has a sealed cavity 11 inside. The sealed cavity 11 is suitable for storing gas. The side wall of the sealed cavity 11 also has a light-transmitting part. At least part of the box body 1 is suitable for being installed in the installation groove 201 so that the light-transmitting part is located between the laser emitter 202 and the laser detector 203.

[0033] Specifically, as Figure 4 shown, the inside of the box body 1 of the calibration device 100 defines a closed sealed cavity 11. The sealed cavity 11 is used to pre-store a calibration gas of a certain concentration. The calibration gas can be CH 4 、CO、CO 2Gases such as this are not specifically restricted here. It can be understood that the sealing cavity 11 can be closed after storing a certain concentration of calibration gas. For example, for the specific intake and outlet ports connected to the sealing cavity 11, when it is necessary to store a certain concentration of calibration gas in the sealing cavity 11, a certain concentration of calibration gas is introduced into the sealing cavity 11 through the intake port. As the calibration gas flows in, part of the air is mixed with the calibration gas and flows out from the outlet port of the sealing cavity 11. During this process, the air in the sealing cavity 11 is gradually replaced by a certain concentration of calibration gas. Subsequently, the intake and outlet ports of the sealing cavity 11 are sealed, thereby achieving the storage of a certain concentration of calibration gas in the sealing cavity 11. Or, the assembly of the calibration device 100 can also be placed in a sealed tooling filled with a certain concentration of calibration gas. When the calibration device 100 is assembled, the sealing cavity 11 in the calibration device 100 also stores a certain concentration of calibration gas. Of course, there are other methods, which will not be exemplified one by one here. With such a setting, different concentrations of calibration gas can be pre-stored in different calibration devices 100 according to the calibration requirements.

[0034] Further, the side wall of the sealing cavity 11 also has a light-transmitting part. Refer to Figure 2 and Figure 4 As shown, when the calibration device 100 is used in cooperation with the laser gas sensor 200, at least part of the box body 1 is installed in the installation groove 201. The installation method can include, but is not limited to, directly inserting at least part of the box body 1 into the installation groove 201. That is to say, the box body 1 can be completely inserted and installed in the installation groove 201 of the laser gas sensor 200, or only the lower part can be inserted and installed in the installation groove 201 of the laser gas sensor 200, which is specifically designed according to the structure of the laser sensor and is not specifically restricted here. Further, when the calibration device 100 is assembled in cooperation with the laser gas sensor 200, as Figure 4 shown, the light-transmitting part is located between the laser emitter 202 and the laser detector 203. With such a setting, when the laser emitter 202 emits a laser beam, the laser beam can enter the sealing cavity 11 filled with a certain concentration of calibration gas and enter the laser detector 203 from the sealing cavity 11, and the laser detector 203 performs concentration calibration according to the received laser beam.

[0035] As a specific example, when it is necessary to calibrate the concentration of the laser gas sensor 200, calibration devices 100 with different known concentrations of calibration gas are prepared in advance. For example, calibration devices 100 with 20%, 40%, 60%, and 80% concentrations of CH 4 gas are prepared in advance. First, the laser gas sensor 200 calibrates the 20% concentration of CH 4 gas. The calibration device 100 with 20% concentration of CH 4The calibration device 100 for the gas is installed in the installation groove 201 of the laser gas sensor 200, ensuring that the light-transmitting part is located between the laser emitter 202 and the laser detector 203. Subsequently, the laser emitter 202 emits a laser beam, and the laser detector 203 calibrates the concentration of the 20% concentration CH 4 gas. After the calibration is completed, the calibration device 100 for the 20% concentration CH 4 gas is taken out from the installation groove 201 of the laser gas sensor 200, and then the calibration device 100 with 40% concentration CH 4 gas is replaced for concentration calibration. And so on, the laser gas sensor 200 completes the concentration calibration for 60% concentration CH 4 gas and 80% concentration CH 4 gas in the same way.

[0036] Thus, by replacing the calibration device 100 with calibration gases of different concentrations, multi-concentration point calibration of the laser gas sensor 200 can be achieved, which simplifies the calibration process and reduces the influence of the gas path connection method, plugging and unplugging of the gas path, and unstable ventilation state on the calibration result in the traditional calibration method, improving the calibration accuracy. At the same time, the calibration device 100 can be reused repeatedly, which is beneficial to reducing the manufacturing cost of the laser gas sensor 200.

[0037] In some embodiments of the present invention, as Figures 1 - 4 shown, the box body 1 further has a first light-transmitting part 12 and a second light-transmitting part 13 which are oppositely arranged. The first light-transmitting part 12 and the second light-transmitting part 13 are the side walls of the sealed cavity 11. At least part of the box body 1 is adapted to be installed in the installation groove 201 so that the first light-transmitting part 12 is opposite to the laser emitter 202 and the second light-transmitting part 13 is opposite to the laser detector 203.

[0038] That is to say, as Figure 4 shown, the box body 1 further has a first light-transmitting part 12 and a second light-transmitting part 13 which are oppositely arranged. Optionally, the first light-transmitting part 12 and the second light-transmitting part 13 are configured as the side walls of the sealed cavity 11. When the calibration device 100 is assembled with the laser gas sensor 200, as Figure 4 shown, it is necessary to ensure that the first light-transmitting part 12 is opposite to the laser emitter 202 and the second light-transmitting part 13 is opposite to the laser detector 203. With such a setting, when the laser emitter 202 emits a laser beam, the laser beam can enter the sealed cavity 11 filled with a certain concentration of calibration gas from the first light-transmitting part 12 and enter the laser detector 203 from the second light-transmitting part 13, and the laser detector 203 calibrates the concentration according to the received laser beam.

[0039] The calibration method of the laser gas sensor is introduced in detail below. The calibration method of the laser gas sensor includes the following steps:

[0040] Step S1: Calibrate using a calibration device storing nitrogen or zero air gas to obtain a first gas absorption peak, calibrate using a calibration device storing a calibration gas with a preset concentration to obtain a second gas absorption peak, and obtain a first calibration coefficient based on the first gas absorption peak, the preset concentration, and the second gas absorption peak.

[0041] It should be noted that the laser gas sensor 200 is calibrated using the above-mentioned calibration device 100, and the laser gas sensor 200 is used in cooperation with the calibration device 100. Specifically, the laser emitter 202 of the laser gas sensor 200 is used to emit a laser beam, and the laser detector 203 is used to receive the laser beam and calculate the gas absorption peak after the laser beam passes through the calibration device 100 with a calibration gas of a certain concentration. It can be understood that the gas absorption peak is calculated by the laser detector 203 based on the received laser signal through a series of algorithms such as filtering and demodulation. The calculation of the gas absorption peak belongs to the prior art for the laser gas sensor 200 and will not be further explained here.

[0042] As a specific example, assume that the laser gas sensor 200 calibrates the concentration of CH 4 gas. First, install the calibration device 100 storing nitrogen or zero air gas in the installation groove 201 of the laser gas sensor 200. Subsequently, the laser emitter 202 emits a laser beam, which enters the sealed chamber 11 filled with nitrogen or zero air through the first light-transmitting part 12 and enters the laser detector 203 through the second light-transmitting part 13. The laser detector 203 then obtains the first gas absorption peak based on the received laser beam. Subsequently, take out the calibration device 100 storing nitrogen or zero air gas from the installation groove 201 of the laser gas sensor 200 and replace it with the calibration device 100 with 100% concentration of CH 4 gas. Similarly, obtain the second gas absorption peak of the laser beam after passing through the calibration device 100 with 100% concentration of CH 4 gas through the laser detector 203, and then obtain the first calibration coefficient based on the first gas absorption peak, the preset concentration, and the second gas absorption peak.

[0043] In some embodiments of the present invention, the first calibration coefficient satisfies the following relationship:

[0044]

[0045] where b is the first calibration coefficient, C 1 is the preset concentration, Vpp 0 is the first gas absorption peak, and Vpp 1 is the second gas absorption peak.

[0046] Step S2, obtain the interval distance between the laser emitter and the laser detector and the transmission distance of the laser beam between the first light-transmitting part and the second light-transmitting part, and obtain a correction coefficient according to the interval distance and the transmission distance.

[0047] It should be noted that, as Figure 4 shown, when the laser emitter 202 emits a laser beam to the laser detector 203, the transmission distance of the laser beam between the first light-transmitting part 12 and the second light-transmitting part 13 is less than the interval distance between the laser emitter 202 and the laser detector 203. Actually, the transmission distance of the laser beam between the first light-transmitting part 12 and the second light-transmitting part 13 is the effective absorption optical path of the laser beam in the CH 4 gas. Therefore, a correction coefficient needs to be introduced, and the correction coefficient is obtained according to the interval distance and the transmission distance.

[0048] In some embodiments of the present invention, the correction coefficient satisfies the following relationship:

[0049] where ε is the correction coefficient, L 1 is the transmission distance, and L 0 is the interval distance.

[0050] Step S3, obtain a second calibration coefficient according to the first gas absorption peak value, the preset concentration, the second gas absorption peak value, and the correction coefficient.

[0051] That is to say, the correction coefficient is introduced into the acquisition of the second calibration coefficient. Specifically, the second calibration coefficient is obtained according to the first gas absorption peak value, the preset concentration, the second gas absorption peak value, and the correction coefficient.

[0052] In some embodiments of the present invention, the second calibration coefficient satisfies the following relationship:

[0053]

[0054] where k is the second calibration coefficient, C 1 is the preset concentration, Vpp 0 is the first gas absorption peak value, Vpp 1 is the second gas absorption peak value, and ε is the correction coefficient.

[0055] Step S4, measure the calibration device storing the standard concentration gas according to the first calibration coefficient and the second calibration coefficient, and obtain the measured concentration corresponding to the standard concentration, where the standard concentration is less than the preset concentration.

[0056] Specifically, after obtaining the first calibration coefficient and the second calibration coefficient, a calibration equation can be obtained. Among them, the calibration equation is:

[0057] C = k·Vpp + b,

[0058] Wherein, C is the calibrated concentration, b is the first calibration coefficient, k is the second calibration coefficient, and Vpp is the gas absorption peak value.

[0059] That is to say, for any standard concentration gas, the measured concentration corresponding to the standard concentration can be obtained through the above calibration equation.

[0060] For example, assume the standard concentration is 20%. When the laser gas sensor 200 needs to measure the concentration of 20% CH 4 gas, the calibration device 100 for 20% concentration CH 4 gas is installed in the installation groove 201 of the laser gas sensor 200. The gas absorption peak value after the laser beam passes through the calibration device 100 for 20% concentration CH 4 gas is obtained through the laser detector 203. According to the above calibration equation, the measured concentration corresponding to 20% concentration of CH 4 gas can be calculated. By analogy, the measured concentrations corresponding to 40% concentration CH 4 gas, 60% concentration CH 4 gas, and 80% concentration CH 4 gas of the laser gas sensor 200 can be obtained in the same way.

[0061] Step S5: Obtain the calibration result according to the standard concentration and the measured concentration.

[0062] Specifically, after obtaining the measured concentration corresponding to the standard concentration according to the above calibration formula, the calibration result is obtained according to the standard concentration and the measured concentration.

[0063] In some embodiments of the present invention, obtaining the calibration result according to the standard concentration and the measured concentration includes: obtaining the absolute error value according to the standard concentration and the measured concentration; if the absolute error value is less than or equal to the calibration threshold, the calibration result is successful; if the absolute error value is greater than the calibration threshold, the calibration result is failed.

[0064] Specifically, assume the standard concentration is 20%. After obtaining the measured concentration corresponding to 20% concentration of CH 4 gas, calculate the absolute error value between 20% and the measured concentration corresponding to 20% concentration of CH 4 gas. If the absolute error value is less than or equal to the calibration threshold, the calibration result is successful; if the absolute error value is greater than the calibration threshold, the calibration result is failed. Wherein, the calibration threshold can be 3% LEL, and LEL is the lower explosion limit value of CH 4 gas.

[0065] Thus, when calibrating the concentration of the laser gas sensor 200 using the above-mentioned calibration device 100, a correction coefficient is determined based on the obtained distance between the laser emitter 202 and the laser detector 203 and the transmission distance of the laser beam between the first light-transmitting part 12 and the second light-transmitting part 13, so as to calibrate the concentration of the laser gas sensor 200 according to the first calibration coefficient and the corrected second calibration coefficient, reducing the influence of the calibration device 100 on the concentration calibration and being beneficial to improving the accuracy of calibration.

[0066] In some embodiments of the present invention, such as Figure 1 and Figure 4 shown, the box body 1 includes: a cover plate 14 and a base 15. The base 15 has a gas groove 151, and the cover plate 14 is used to seal the gas groove 151 to be adapted to jointly define a sealed cavity 11 with the base 15.

[0067] Specifically, as Figure 1 shown, the box body 1 is assembled by the cover plate 14 and the base 15. The cover plate 14 can be selected but is not limited to a metal material, such as stainless steel, etc. The base 15 has a gas groove 151. When the cover plate 14 and the base 15 are assembled in cooperation, referring to Figure 1 and Figure 2 shown, the cover plate 14 is used to seal the gas groove 151 and jointly define the sealed cavity 11 with the base 15. It should be noted that when it is necessary to store a certain concentration of calibration gas in the sealed cavity 11, the cover plate 14 and the base 15 can be placed in a sealed tooling filled with a certain concentration of calibration gas for assembly. Since the base 15 is in the sealed tooling filled with a certain concentration of calibration gas, the gas groove 151 of the base 15 is filled with a certain concentration of calibration gas. When the gas groove 151 is sealed by the cover plate 14, a certain concentration of calibration gas is also stored in the sealed cavity 11. With such a setting, multiple box bodies 1 can be produced in the sealed tooling with the same concentration of calibration gas, which is beneficial to improving the production efficiency of the calibration device 100.

[0068] In some embodiments of the present invention, such as Figure 4 shown, the first light-transmitting part 12 and the second light-transmitting part 13 are the side walls of the gas groove 151. At least part of the base 15 is adapted to be installed in the installation groove 201 so that the first light-transmitting part 12 is opposite to the laser emitter 202 and the second light-transmitting part 13 is opposite to the laser detector 203.

[0069] Specifically, as Figure 4As shown, the relatively arranged first light-transmitting part 12 and second light-transmitting part 13 can be configured as the side walls of the gas tank 151. When the calibration device 100 is used in cooperation with the laser gas sensor 200, at least part of the base 15 is installed in the installation groove 201. The installation method can include but is not limited to directly inserting at least part of the base 15 into the installation groove 201. That is to say, the base 15 can be completely inserted and installed in the installation groove 201 of the laser gas sensor 200, or only the lower part can be inserted and installed in the installation groove 201 of the laser gas sensor 200, which is specifically designed according to the structure of the laser sensor and is not specifically limited here. Further, when the calibration device 100 and the laser gas sensor 200 are assembled in cooperation, as Figure 4 shown, it is necessary to ensure that the first light-transmitting part 12 is opposite to the laser emitter 202 and the second light-transmitting part 13 is opposite to the laser detector 203. With such a setting, when the laser emitter 202 emits a laser beam, the laser beam can enter the gas tank 151 filled with a calibration gas of a certain concentration from the first light-transmitting part 12 and enter the laser detector 203 from the second light-transmitting part 13. The laser detector 203 performs concentration calibration according to the received laser beam. The concentration calibration process is simple and convenient, reducing the influence of external factors on the calibration result.

[0070] In some embodiments of the present invention, the first light-transmitting part 12 is configured as a first light-transmitting plate, and the first light-transmitting plate has a first angle α with the bottom wall of the gas tank 151, satisfying the relational expression: 30° ≤ α ≤ 60°. The second light-transmitting part 13 is configured as a second light-transmitting plate, and the second light-transmitting plate has a second angle β with the bottom wall of the gas tank 151, satisfying the relational expression: 30° ≤ β ≤ 60°.

[0071] Specifically, as Figure 4 shown, the bottom wall of the gas tank 151 is horizontally arranged. The first light-transmitting plate has a first angle α with the bottom wall of the gas tank 151, and the second light-transmitting plate has a second angle β with the bottom wall of the gas tank 151. Among them, the first angle α satisfies the relational expression: 30° ≤ α ≤ 60°, and the second angle β satisfies the relational expression: 30° ≤ β ≤ 60°. For example, the first angle α can be 30°, 45°, 60°, etc., and the second angle β can be 30°, 45°, 60°, etc. The first angle α can be equal to the second angle β or not equal to the second angle β, which is specifically set according to actual needs and is not specifically limited here.

[0072] As a specific example, assume that the first included angle α between the first light-transmitting plate and the bottom wall of the gas groove 151 is 45°, and the second included angle β between the second light-transmitting plate and the bottom wall of the gas groove 151 is 45°. When the laser emitter 202 emits a horizontal laser beam towards the laser detector 203, both the first light-transmitting plate and the second light-transmitting plate have an included angle with the laser beam. With such a setting, it is possible to prevent the laser beam from being perpendicularly incident on the first light-transmitting plate and perpendicularly exiting the second light-transmitting plate, thereby avoiding the generation of reflected stray light, and further avoiding the reflected stray light from entering the optical path system of the laser gas sensor 200 and causing optical interference noise. That is, the inclined design of the first light-transmitting plate and the second light-transmitting plate can eliminate the optical interference noise.

[0073] In some embodiments of the present utility model, the material of the base 15 is an acrylic plate. That is to say, the base 15 can be made of an acrylic plate. It can be understood that the acrylic plate is a transparent material. When the base 15 is produced using an acrylic plate, there is no need to specifically provide the first light-transmitting portion 12 and the second light-transmitting portion 13 on the base 15. Optionally, the base 15 can be selected as a high-transparency acrylic plate to improve the light transmittance, thereby ensuring a high light transmittance when the laser beam passes through the calibration device 100 and reducing the influence of the calibration device 100 on the calibration result.

[0074] In some embodiments of the present utility model, as Figure 1 shown, the box body 1 further includes: a seal 2. The base 15 further has a seal groove 152 surrounding the opening of the gas groove 151, and the seal 2 is disposed in the seal groove 152. Specifically, both the cover plate 14 and the base 15 are provided with threaded holes. When the cover plate 14 and the base 15 are assembled in cooperation, the seal 2 is disposed in the seal groove 152, and the cover plate 14 and the base 15 are fixedly connected by screwing a fastener 3 (bolt) with the threaded holes. With such a setting, the good airtightness of the calibration device 100 can be ensured through the seal 2 for a long time.

[0075] It should be noted that in the description of the present utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present utility model. In addition, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, unless otherwise specified, the meaning of "a plurality" is two or more.

[0076] In the description of the present utility model, it should be noted that unless otherwise clearly defined and limited, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0077] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0078] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" can explicitly or implicitly include at least one of such features. In the description of the present utility model, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0079] In the present utility model, unless otherwise clearly defined and limited, the terms "installation", "connection", "coupling", "fixing", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0080] Although the embodiments of the present utility model have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as a limitation to the present utility model. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present utility model.

Claims

1. A calibration device for a laser gas sensor, characterized in that: The laser gas sensor has a mounting groove, and the side wall of the mounting groove has a laser emitter and a laser detector arranged opposite to each other, and the laser detector is used to receive the laser beam emitted by the laser emitter. The calibration device includes: A box body, wherein the box body has a sealed cavity, the sealed cavity is suitable for storing gas, the side wall of the sealed cavity also has a light-transmitting portion, and at least a portion of the box body is suitable for being installed in the installation groove so that the light-transmitting portion is located between the laser emitter and the laser detector.

2. The calibration device according to claim 1, characterized in that: The box body also has a first light-transmitting portion and a second light-transmitting portion that are arranged opposite to each other, the first light-transmitting portion and the second light-transmitting portion are side walls of the sealed cavity, and at least a portion of the box body is suitable for being installed in the installation groove so that the first light-transmitting portion is opposite to the laser emitter and the second light-transmitting portion is opposite to the laser detector.

3. The calibration device according to claim 2, characterized in that: The box body comprises: A cover plate and a base, wherein the base has a gas groove, and the cover plate is used to seal the gas groove so as to define the sealed cavity together with the base.

4. The calibration device according to claim 3, characterized in that: The first light-transmitting portion and the second light-transmitting portion are side walls of the gas groove, and at least a portion of the base is suitable for being installed in the installation groove so that the first light-transmitting portion is opposite to the laser emitter and the second light-transmitting portion is opposite to the laser detector.

5. The calibration device according to claim 4, characterized in that: The first light-transmitting portion is configured as a first light-transmitting plate, and the first light-transmitting plate and the bottom wall of the gas groove have a first angle α, satisfying the relationship: 30°≤α≤60°; The second light-transmitting portion is configured as a second light-transmitting plate, and a second angle β is formed between the second light-transmitting plate and the bottom wall of the gas groove, satisfying the relationship: 30°≤β≤60°.

6. The calibration device according to claim 3, characterized in that: The base is made of acrylic plate.

7. The calibration device according to any one of claims 3 to 6, characterized in that: The box body further comprises: a sealing member, the base further comprises a sealing groove surrounding the opening of the gas groove, and the sealing member is arranged in the sealing groove.

Images