Airborne infrared spectrometer for monitoring VOCs (volatile organic compounds) in oil area and use method of airborne infrared spectrometer

Abstract

The invention discloses an airborne infrared spectrometer for monitoring VOCs in an oil area and a use method thereof, and relates to the technical field of VOCs gas detection.The airborne infrared spectrometer comprises an airborne platform, a spectrometer system platform is arranged on the airborne platform, and a gas pool, an active spectrometer light source and a Fourier transform spectrometer are arranged on the spectrometer system platform; the active spectrometer light source and the Fourier transform spectrometer are respectively positioned on the left side and the right side of the gas cell and are oppositely arranged; the gas tank is connected with a VOCs concentration detection assembly used for monitoring the VOCs evaporation process, and an exhaust pipe is further arranged at the top of the gas tank; the VOCs concentration detection assembly comprises an evaporation chamber and a PID detector, the evaporation chamber is mounted on the airborne platform, a VOCs liquid sample introduction pipeline is arranged at the lower part of the evaporation chamber, and the top of the evaporation chamber is connected with the gas tank through a gas inlet pipe; the PID detector is mounted at the top of the evaporation chamber; the oil area VOCs specific pollutant detection method based on Fourier infrared spectroscopy and PID detection has high efficiency, and the VOCs specific pollutants can be rapidly and accurately detected.

Description

Technical Field

[0001] The present invention relates to the technical field of VOCs gas detection, and in particular to an airborne infrared spectrometer for monitoring VOCs in oil fields and a method for using the same. Background Art

[0002] With the continued rapid development of my country's economy, the total amount of volatile organic compounds (VOCs) emitted from industrial sources has increased annually, leading to increasingly prominent environmental pollution issues. Most VOCs are highly toxic and serve as key precursors to photochemical smog and PM2.5, significantly impacting regional atmospheric ozone, PM2.5 pollution, and human health. For petrochemical-related industrial parks and enterprises with high VOC emissions, most lack VOC monitoring and surveillance capabilities, making VOC environmental monitoring a key management shortcoming of chemical parks. Monitoring VOC emissions is essential for implementing national VOC pollution prevention and control plans.

[0003] VOCs gas detection methods mainly include gas chromatography, PID detector, differential optical absorption spectrometer, infrared absorption detector, and laser detector. Gas chromatography can analyze the type and content of VOCs, but it requires a gas system to sample and separate the gas, which is not convenient for daily detection needs and cannot be monitored in real time. PID detector uses ultraviolet light to ionize organic molecules into positive and negative ions that can be detected by the detector. The detector captures the positive and negative charges of the ionized gas and converts them into current signals to measure gas concentration. It has high precision and accuracy, but cannot qualitatively distinguish different compounds. The differential optical absorption spectrometer is based on the "fingerprint" characteristic absorption of light radiation by trace VOCs gas components to achieve qualitative and quantitative measurement. It can measure multiple gas components simultaneously, with high measurement accuracy and a low detection limit. It can operate in real time, continuously, and for a long time. It is simple to operate and has low operating costs, but its sensitivity is relatively low and the cost is also high. The laser detector uses tunable semiconductor laser absorption spectroscopy (TDLAS) gas analysis technology. TDLAS technology has the characteristics of high sensitivity, good selectivity, real-time and dynamic, but for low molecular weight substances such as formaldehyde, there are certain difficulties in selectively monitoring other more harmful trace VOCs components in the air.

[0004] With the continuous advancement of optoelectronic technology, spectroscopy has become a hot topic for research and application worldwide due to its rapidity, real-time performance, and high efficiency in gas detection. Compared to traditional techniques, spectroscopy offers the advantages of rapidity, high efficiency, and real-time analysis. To meet the requirements of high stability, fast processing speed, and the ability to simultaneously measure a wide range of gases, Fourier transform infrared spectroscopy (FTIR) has been gradually applied to gas detection. Fourier transform infrared spectroscopy (FTIR), an optical gas detection technique, offers advantages such as high resolution, high sensitivity, high signal-to-noise ratio, high throughput, and wide bandwidth. The instrument measures and analyzes the characteristic absorption spectra of infrared radiation "fingerprints" of atmospheric trace gas components, enabling automated online qualitative and quantitative monitoring of multi-component gases. Its operating principle is that the spectrometer's optical lens receives infrared radiation emitted by an infrared light source. This infrared radiation propagates through open or closed air. After receiving infrared radiation from the spectrometer, it is modulated by an interferometer and detected by an infrared detector. The spectrometer's electronics and corresponding data processing module then convert and store the interference pattern. The interference pattern is then converted into an infrared spectrum through Fourier transform. Its advantages include the ability to perform both quantitative and qualitative analysis, rapid measurement, non-destructive testing, minimal sample usage, ease of operation, and high analytical sensitivity. However, its accuracy is lower than that of analytical methods such as gas chromatography, mass spectrometry, and vibrational spectroscopy. CN201910967153.6 discloses a portable infrared spectrometer suitable for VOC detection, and CN202122206901.4 discloses an infrared spectrometer suitable for VOC detection. Neither of these technical solutions addresses the low accuracy of infrared spectrometers. Therefore, a method combining a PID detector with FTIR spectroscopy is proposed. By calibrating a Fourier transform infrared spectrometer, it can be used to quantitatively analyze a range of volatile organic compounds. The designed multi-channel gas cell extends the sensitivity of the Fourier transform infrared spectrometer, enabling quantitative detection of VOCs in oil-rich areas. Summary of the Invention

[0005] The purpose of the present invention is to address the defects of the existing technology and provide an airborne infrared spectrometer for monitoring VOCs in oil fields and a method for using the same.

[0006] The technical solution of the present invention is: an airborne infrared spectrometer for monitoring VOCs in oil fields, including an airborne platform, on which a spectrometer system platform is provided, the spectrometer system platform is provided with a gas pool, an active spectrometer light source and a Fourier transform spectrometer, the active spectrometer light source and the Fourier transform spectrometer are respectively located on the left and right sides of the gas pool, and the two are arranged opposite to each other; the gas pool is connected to a VOCs concentration detection component for monitoring the VOCs evaporation process, and an exhaust pipe is also provided on the top of the gas pool.

[0007] Preferably, the VOCs concentration detection component includes an evaporation chamber and a PID detector. The evaporation chamber is installed on an airborne platform, and a VOCs liquid sampling pipe is provided at the bottom thereof, and the top thereof is connected to the top of the gas pool through an air inlet pipe; valves are provided on the VOCs liquid sampling pipe, the air inlet pipe and the exhaust pipe, and the PID detector is installed on the top of the evaporation chamber.

[0008] Preferably, a gas vacuum pump is provided on the exhaust pipe.

[0009] Preferably, the Fourier transform spectrometer is a rotating mirror Fourier transform spectrometer.

[0010] Preferably, the rotating mirror Fourier transform spectrometer includes a front optical system, a beam splitter, a converging optical system, a detector, a first reflector assembly and a second reflector assembly, wherein the first reflector assembly and the second reflector assembly are respectively located on both sides of the beam splitter, the first reflector assembly includes a first rotating mirror, an angle mirror and a movable arm vertical reflector, and the second reflector assembly includes a second rotating mirror, a first plane reflector and a second plane reflector; the rear sides of the first rotating mirror and the second rotating mirror are both connected to a motor; The radiation of the detected target is collimated by the front optical system and then incident on a beam splitter coated with a semi-transparent and semi-reflective film. The beam splitter divides the light beam into a reflected beam and a transmitted beam. The reflected beam is reflected by the first rotating mirror to the corner mirror, and the corner mirror reflects it back to the first rotating mirror, and then reflects it to the vertical mirror, and then returns to the beam splitter along the original optical path. The transmitted beam returns to the beam splitter along the original optical path through the second rotating mirror, the first plane reflector and the second plane reflector. The reflected beam reflected back to the beam splitter is further divided into a reflected beam and a transmitted beam, and the transmitted beam reflected back to the beam splitter is also divided into a reflected beam and a transmitted beam. The transmitted part of the former and the reflected part of the latter are converged onto the detector through a converging optical system to generate coherent interference and are received by the detector. The first rotating mirror and the second rotating mirror rotate to produce a changing optical path difference between the two beams of light. The interference signals with different optical path differences are received by the detector to obtain an interference spectrum that changes with time. After data inversion, the spectral information of the target is finally obtained.

[0011] Preferably, the first reflective surface of the corner mirror is located on the light reflective path of the first rotating mirror, the first rotating mirror is located on the light reflective path of the second reflective surface of the corner mirror, and the boom vertical reflective mirror is located on the light reflective path of the first rotating mirror.

[0012] Preferably, the first plane reflector is located on the light reflection path of the second rotating mirror, and the second plane reflector is located on the light reflection path of the first plane reflector.

[0013] A method for using an airborne infrared spectrometer for monitoring VOCs in oil fields comprises the following steps: 1) Inject different amounts of VOCs into the evaporation chamber and monitor the concentration over time through the PID detector and computer interface; 2) When the count provided by the PID detector is constant, indicating that the evaporation chamber cavity has reached a state of equilibrium, corresponding to the maximum evaporation of the liquid, the valve on the air inlet pipe is opened to deliver the gas to the gas pool; 3) Immediately after opening the connection between the evaporation chamber and the gas pool, spectral data were collected using a rotating mirror Fourier transform spectrometer, while simultaneously recording the PID detector reading. When the spectrum reached a constant intensity, equilibrium was achieved between the evaporation chamber and the gas pool. Spectral data were collected for statistical analysis and linear fitting was performed using a coupled correction algorithm to determine the calibration curve. 4) After the spectrum measurement is completed, the gas in the gas pool is discharged through the gas vacuum pump on the exhaust pipe for the next measurement.

[0014] Compared with the prior art, the present invention has the following advantages: The method for detecting VOCs characteristic pollutants in oil fields based on Fourier infrared spectroscopy and PID detection is highly efficient and can detect VOCs characteristic pollutants quickly and accurately. This method combines the high resolution of the Fourier transform spectrometer and the sensitivity of the PID detector, and can accurately detect VOCs characteristic pollutants in oil fields with high sensitivity and a wide detection range. This method is not only suitable for environmental monitoring and governance in oil fields, but can also be applied to other fields, such as the detection of volatile organic compound pollutants in chemical, food, and pharmaceutical industries. The sample pretreatment is simple: During the experiment, the pretreatment of the sample is relatively simple and does not require too many complex operations. The test results are reliable: Through further processing in the gas pool, the concentration of VOCs characteristic pollutants can be more accurately quantitatively analyzed, providing more reliable data support for environmental monitoring and governance. The use of a rotating mirror Fourier transform spectrometer is more stable and can be used for vehicle-mounted or airborne measurements. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 This is the schematic diagram of the rotating mirror Fourier transform spectrometer.

[0016] In the figure: 1. Airborne platform, 2. Spectrometer system platform, 3. Gas pool, 4. Active spectrometer light source, 5. Fourier transform spectrometer, 6. Exhaust pipe, 7. Gas vacuum pump, 8. Evaporation chamber, 9. PID detector, 10. VOCs liquid sampling pipeline, 11. Inlet pipe, 12. Valve, 13. Front optical system, 14. Beam splitter, 15. Converging optical system, 16. Detector, 17. First rotating mirror, 18. Corner mirror, 19. Boom vertical reflector, 20. Second rotating mirror, 21. First plane reflector, 22. Second plane reflector, 23. Motor. DETAILED DESCRIPTION

[0017] The present invention is further described below with reference to the accompanying drawings and embodiments. Example 1

[0018] Reference Figure 1 As shown, an airborne infrared spectrometer for monitoring VOCs in oil fields includes an airborne platform 1, on which a spectrometer system platform 2 is provided. The spectrometer system platform 2 is provided with a gas pool 3, an active spectrometer light source 4 and a Fourier transform spectrometer 5. The active spectrometer light source 4 and the Fourier transform spectrometer 5 are respectively located on the left and right sides of the gas pool 3, and the two are arranged opposite to each other; the gas pool 3 is connected to a VOCs concentration detection component for monitoring the evaporation process of VOCs, and an exhaust pipe 6 is also provided on the top of the gas pool.

[0019] The VOCs concentration detection component includes an evaporation chamber 8 and a PID detector 9. The evaporation chamber 8 is installed on the airborne platform 1. A VOCs liquid sampling pipe 10 is provided at the bottom of the evaporation chamber 8, and its top is connected to the top of the gas pool 3 through an air inlet pipe 11; valves 12 are provided on the VOCs liquid sampling pipe 10, the air inlet pipe 11 and the exhaust pipe 6, and the PID detector 9 is installed on the top of the evaporation chamber 8.

[0020] When used, the following steps are included: 1) Inject different amounts of VOCs into the evaporation chamber 8 and monitor the concentration over time through the PID detector 9 and the computer interface; 2) When the count provided by the PID detector 9 is constant, indicating that the evaporation chamber 8 has reached an equilibrium state, corresponding to the maximum evaporation of the liquid, the valve 12 on the air inlet pipe 11 is opened to deliver the gas to the gas pool 3; 3) Immediately after opening the connection between the evaporation chamber 8 and the gas pool 3, spectral data is collected using the Fourier transform spectrometer 5, while simultaneously recording the reading of the PID detector 9; when the spectrum reaches a constant intensity, equilibrium is reached between the evaporation chamber 8 and the gas pool 3; the spectral data is collected for statistical data analysis, and a coupled correction algorithm is used for linear fitting to determine a calibration curve; 4) After the spectrum measurement is completed, the gas in the gas pool 3 is discharged through the exhaust pipe 6 so that the next measurement can be carried out.

[0021] The following details the characteristics of each part of the device: The gas pool 3 is connected to the sealed evaporation chamber 8 through the air inlet pipe 11 so that the evaporated VOCs can be transported to the gas pool 3 for spectral analysis. In the evaporation chamber 8, the PID detector 9 is connected to the upper part of the evaporation chamber 8 for real-time monitoring of the evaporation process of the VOCs. When the count provided by the PID detector 9 is constant, it indicates that the equilibrium state is reached in the evaporation chamber 8, corresponding to the maximum evaporation of the liquid. At this time, the valve 12 on the air inlet pipe 11 is opened to transport the gas to the gas pool 3 in the spectrometer. In the gas pool 3, the gas sample is spectrally measured by the Fourier transform spectrometer 5. The Fourier transform spectrometer 5 can quickly collect spectral data, and the collected spectral data is used for subsequent statistical data analysis.

[0022] The evaporation chamber 8 is a sealed container used to convert liquid VOCs into gaseous form. It is connected to a PID detector 9, which monitors the evaporation process of the VOCs in real time. This design helps ensure the stability and accuracy of the evaporation process. The evaporation chamber 8 is connected to the gas pool 3 via an air inlet pipe 11, allowing the evaporated VOCs to be transported to the gas pool 3 for spectral analysis. Furthermore, the evaporation chamber 8 is also connected to a computer interface via the PID detector 9 for real-time monitoring of the VOC evaporation process.

[0023] The Fourier transform spectrometer 5 is a high-precision spectral analysis instrument used to measure the infrared absorption spectrum of VOCs. This detector can provide high-resolution and accurate spectral data for determining the composition and concentration of VOCs. Furthermore, the Fourier transform spectrometer 5 offers advantages such as fast scanning and automated operation, which can improve detection efficiency. By analyzing the VOCs' absorption characteristics of infrared light, the Fourier transform spectrometer 5 can determine the composition and concentration of VOCs. Furthermore, the Fourier transform spectrometer 5 can provide qualitative and quantitative analysis results, providing a basis for subsequent data processing.

[0024] The PID detector 9 is a highly sensitive detector used to measure VOC concentrations. It detects VOCs by ionizing them and measuring their ionization current. It offers advantages such as high sensitivity, a wide detection range, and a fast response. Furthermore, its small size, light weight, and portability make it suitable for use in portable VOC detection systems.

[0025] The method for detecting VOCs characteristic pollutants in oil fields based on Fourier infrared spectroscopy and PID detection is highly efficient and can quickly and accurately detect VOCs characteristic pollutants; this method combines the high resolution of the Fourier transform spectrometer 5 and the sensitivity of the PID detector 9, and can accurately detect VOCs characteristic pollutants in oil fields with high sensitivity and a wide detection range; this method is not only suitable for environmental monitoring and governance in oil fields, but can also be applied to other fields, such as the detection of volatile organic compound pollutants in chemical, food, pharmaceutical and other fields; sample pretreatment is simple: during the experiment, the pretreatment of the sample is relatively simple and does not require too many complicated operations; the detection results are reliable: through further processing of the gas pool 3, the concentration of VOCs characteristic pollutants can be more accurately quantitatively analyzed, providing more reliable data support for environmental monitoring and governance. Example 2

[0026] As a preferred embodiment of the present invention, this embodiment is additionally provided with a gas vacuum pump 7 on the basis of the first embodiment, specifically: In this embodiment, a gas vacuum pump 7 is provided on the exhaust pipe 6. After the spectrum measurement is completed, the gas in the gas pool 3 needs to be discharged by the gas vacuum pump 7 on the exhaust pipe 6 so as to perform the next measurement. Example 3

[0027] As a preferred embodiment of the present invention, this embodiment selects the type of Fourier transform spectrometer 5 based on the first embodiment, specifically: In this embodiment, the Fourier transform spectrometer 5 is a rotating mirror Fourier transform spectrometer 5. The rotating mirror Fourier transform spectrometer 5 is more stable and can be used for vehicle-mounted or airborne measurements. The vibration generated during the movement of vehicles, aircraft, drones, etc. has little effect on the rotating mirror Fourier transform spectrometer 5. Example 4

[0028] As a preferred embodiment of the present invention, this embodiment optimizes the design of the rotating mirror Fourier transform spectrometer 5 based on the third embodiment, specifically: Reference Figure 2 As shown, the rotating mirror Fourier transform spectrometer 5 includes a front optical system 13, a beam splitter 14, a converging optical system 15, a detector 16, a first reflector assembly and a second reflector assembly. The first reflector assembly and the second reflector assembly are respectively located on both sides of the beam splitter 14. The first reflector assembly includes a first rotating mirror 17, an angle mirror 18 and a movable arm vertical reflector 19. The second reflector assembly includes a second rotating mirror 20, a first plane reflector 21 and a second plane reflector 22. The rear sides of the first rotating mirror 17 and the second rotating mirror 20 are both connected to a motor 23.

[0029] The radiation of the detected target is collimated by the front optical system 13 and incident on the beam splitter 14 coated with a semi-transparent and semi-reflective film. The beam splitter 14 divides the light beam into a reflected beam and a transmitted beam; the reflected beam is reflected by the first rotating mirror 17 to the corner mirror 18, and the corner mirror 18 reflects it back to the first rotating mirror 17, and then reflects it to the vertical reflector, and then returns to the beam splitter 14 along the original optical path; the transmitted beam is returned to the beam splitter 14 along the original optical path through the second rotating mirror 20, the first plane reflector 21 and the second plane reflector 22; the beam reflected back to the beam splitter 14 The reflected light beam is further divided into a reflected light beam and a transmitted light beam, and the transmitted light beam reflected back to the beam splitter 14 is also divided into a reflected light beam and a transmitted light beam. The transmitted part of the former and the reflected part of the latter are converged onto the detector 16 via the converging optical system 15 to generate coherent interference and are received by the detector 16; the first rotating mirror 17 and the second rotating mirror 20 rotate to thereby generate a changing optical path difference between the two beams of light. The interference signals with different optical path differences are received by the detector 16 to obtain an interference spectrum that changes with time. After data inversion, the spectral information of the target is finally obtained. Example 5

[0030] As a preferred embodiment of the present invention, this embodiment further configures the structures of the first reflector assembly and the second reflector assembly based on the fourth embodiment, specifically: The first reflection surface of the corner mirror 18 is located on the light reflection path of the first rotating mirror 17 , the first rotating mirror 17 is located on the light reflection path of the second reflection surface of the corner mirror 18 , and the boom vertical reflection mirror 19 is located on the light reflection path of the first rotating mirror 17 .

[0031] The first plane reflecting mirror 21 is located on the light reflecting path of the second rotating mirror 20 , and the second plane reflecting mirror 22 is located on the light reflecting path of the first plane reflecting mirror 21 .

[0032] The present invention is not limited to the above-mentioned embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. The contents after the changes still fall within the scope of protection of the present invention.

Claims

1. An airborne infrared spectrometer for monitoring VOCs in oil fields, comprising an airborne platform, a spectrometer system platform being mounted on the airborne platform, and characterized in that: The spectrometer system platform is equipped with a gas pool, an active spectrometer light source and a Fourier transform spectrometer. The active spectrometer light source and the Fourier transform spectrometer are respectively located on the left and right sides of the gas pool, and the two are arranged opposite to each other. The gas pool is connected to a VOCs concentration detection component for monitoring the VOCs evaporation process, and an exhaust pipe is also provided on the top of the gas pool.

2. The airborne infrared spectrometer for monitoring VOCs in oil fields according to claim 1, characterized in that: The VOCs concentration detection component includes an evaporation chamber and a PID detector. The evaporation chamber is installed on an airborne platform, and a VOCs liquid sampling pipe is provided at the bottom of the evaporation chamber. The top of the evaporation chamber is connected to the top of the gas pool through an air inlet pipe. Valves are provided on the VOCs liquid sampling pipe, the air inlet pipe and the exhaust pipe. The PID detector is installed on the top of the evaporation chamber.

3. The airborne infrared spectrometer for monitoring VOCs in oil fields according to claim 2, characterized in that: A gas vacuum pump is provided on the exhaust pipe.

4. The airborne infrared spectrometer for monitoring VOCs in oil fields according to claim 3, characterized in that: The Fourier transform spectrometer is a rotating mirror Fourier transform spectrometer.

5. The airborne infrared spectrometer for monitoring VOCs in oil fields according to claim 4, characterized in that: The rotating mirror Fourier transform spectrometer includes a front optical system, a beam splitter, a converging optical system, a detector, a first reflector assembly and a second reflector assembly, wherein the first reflector assembly and the second reflector assembly are respectively located on both sides of the beam splitter, the first reflector assembly includes a first rotating mirror, an angle mirror and a movable arm vertical reflector, and the second reflector assembly includes a second rotating mirror, a first plane reflector and a second plane reflector; the rear sides of the first rotating mirror and the second rotating mirror are both connected to a motor; The radiation from the target is collimated by the front optical system and then incident on a beam splitter coated with a semi-transparent and semi-reflective film. The beam splitter splits the beam into a reflected beam and a transmitted beam. The reflected beam is reflected by the first rotating mirror to the corner mirror, which reflects it back to the first rotating mirror, then to the vertical reflector, and then returns to the beam splitter along the original optical path. The transmitted light beam returns to the beam splitter along the original optical path through the second rotating mirror, the first plane reflecting mirror and the second plane reflecting mirror; the reflected light beam reflected back to the beam splitter is further divided into a reflected light beam and a transmitted light beam, and the transmitted light beam reflected back to the beam splitter is also divided into a reflected light beam and a transmitted light beam. The transmitted part of the former and the reflected part of the latter are converged onto the detector through a converging optical system to generate coherent interference and are received by the detector; the first rotating mirror and the second rotating mirror rotate to produce a changing optical path difference between the two beams of light. The interference signals with different optical path differences are received by the detector to obtain an interference spectrum that changes with time. After data inversion, the spectral information of the target is finally obtained.

6. The airborne infrared spectrometer for monitoring VOCs in oil fields according to claim 5, characterized in that: The first reflection surface of the corner mirror is located on the light reflection path of the first rotating mirror, the first rotating mirror is located on the light reflection path of the second reflection surface of the corner mirror, and the boom vertical reflection mirror is located on the light reflection path of the first rotating mirror.

7. The airborne infrared spectrometer for monitoring VOCs in oil fields according to claim 5, characterized in that: The first plane reflecting mirror is located on the light reflecting path of the second rotating mirror, and the second plane reflecting mirror is located on the light reflecting path of the first plane reflecting mirror.

8. The method for using the airborne infrared spectrometer for monitoring VOCs in oil fields according to claim 5 is characterized in that: The following steps are involved: 1) Inject different amounts of VOCs into the evaporation chamber and monitor the concentration over time through the PID detector and computer interface; 2) When the count provided by the PID detector is constant, indicating that the evaporation chamber cavity has reached a state of equilibrium, corresponding to the maximum evaporation of the liquid, the valve on the air inlet pipe is opened to deliver the gas to the gas pool; 3) Immediately after opening the connection between the evaporation chamber and the gas pool, spectral data were collected using a rotating mirror Fourier transform spectrometer, while simultaneously recording the PID detector reading. When the spectrum reached a constant intensity, equilibrium was achieved between the evaporation chamber and the gas pool. Spectral data were collected for statistical analysis and linear fitting was performed using a coupled correction algorithm to determine the calibration curve. 4) After the spectrum measurement is completed, the gas in the gas pool is discharged through the gas vacuum pump on the exhaust pipe for the next measurement.

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