Soil ecological environment gas detection system

Abstract

The invention discloses a soil ecological environment gas detection system, and relates to the field of gas detection. The system comprises a gas collecting unit, a gas collecting cavity, an optical signal transmitting unit, an optical signal receiving unit, a gas pressure sensor and a control processing unit, the gas collection unit is used for collecting soil gas in target soil, and the soil gas comprises greenhouse effect gas; the gas collection cavity is used for accommodating soil gas; the optical signal transmitting unit is positioned at one end of the gas collecting cavity; the optical signal receiving unit is positioned at the other end of the gas collection cavity and is used for generating a photoelectric sensing signal; the air pressure sensor is arranged in the air collection cavity; and the control processing unit is used for determining the greenhouse effect gas concentration of the soil gas according to the photoelectric sensing signal, and performing compensation treatment according to the cavity gas pressure to obtain the greenhouse effect gas detection concentration. The soil ecological environment monitoring system has the real-time data processing capability, so that the detection result can be fed back quickly, and timely and accurate information is provided for monitoring and management of the soil ecological environment.

Description

Technical Field

[0001] The present invention relates to the technical field of gas detection, and in particular to a soil ecological environment gas detection system. Background Art

[0002] The increase in GHG (Greenhouse Gas) concentration in the atmosphere is causing global climate change. Compared with industrial systems, GHG emissions from agricultural ecosystems are non-point sources and are highly variable due to climate conditions, soil types and management practices. Nitrogen dioxide (CO2), methane (CH4) and nitrous oxide (N2O) are the three main greenhouse gases in the atmosphere.

[0003] Soil is a very active ecosystem on Earth, and the microbial activities in the soil ecological environment will also produce a large amount of greenhouse gases. And because human agricultural activities, such as tillage, fertilization and irrigation, also significantly affect the activity of soil microorganisms and soil gas emissions, monitoring the gas emissions of the soil ecological environment is very important for assessing regional carbon emissions.

[0004] Traditional soil gas detection solutions usually use samplers to collect gas samples in the soil and then take the gas samples back to the laboratory for analysis. However, this method cannot achieve real-time monitoring, resulting in data that may not accurately reflect rapidly changing environmental conditions in a timely manner. Summary of the invention

[0005] In view of the defects of the above-mentioned background technology, the purpose of the present invention is to provide a soil ecological environment gas detection system to alleviate the technical problem that the current soil ecological environment gas detection lacks timeliness and accuracy.

[0006] To achieve the above-mentioned purpose, the present invention provides a soil ecological environment gas detection system, including a gas collection unit, a gas collecting cavity, an optical signal transmitting unit, an optical signal receiving unit, an air pressure sensor and a control processing unit; the gas collection unit is used to collect soil gas in the target soil, and the soil gas contains greenhouse gas; the gas collecting cavity is connected to the gas collection unit and is used to contain soil gas; the optical signal transmitting unit is located at one end of the gas collecting cavity and is used to transmit a detection optical signal; the optical signal receiving unit is located at the other end of the gas collecting cavity and is arranged opposite to the optical signal transmitting unit, and is used to receive the detection optical signal passing through the gas collecting cavity and generate a photoelectric sensing signal; the air pressure sensor is arranged in the gas collecting cavity and is used to detect the cavity air pressure inside the gas collecting cavity; the control processing unit is respectively connected to the optical signal receiving unit and the air pressure sensor, and is used to determine the greenhouse gas concentration of the soil gas according to the photoelectric sensing signal, and compensate the greenhouse gas concentration according to the cavity air pressure to obtain the greenhouse gas detection concentration of the target soil.

[0007] This embodiment adopts the above-mentioned design, and uses a gas collection unit to directly collect gas samples from the soil, ensuring the directness and real-time nature of the detection. The design of the gas collection cavity ensures the stability of the sample and prevents interference from external gases, further improving the accuracy of the detection. The application of the optical signal transmitting unit and the receiving unit is based on the principle of absorption spectroscopy, and quantitatively analyzes the gas concentration by analyzing the changes in the optical signal passing through the soil gas. This method has high sensitivity and high selectivity. The introduction of the air pressure sensor enables the system to compensate the detection results in real time according to the changes in the air pressure in the cavity, thereby eliminating the influence of air pressure fluctuations on the gas concentration readings and enhancing the accuracy of the measurement results. The control processing unit is the core of the system. It not only processes the photoelectric sensing signal and determines the gas concentration, but also combines the air pressure data for intelligent compensation processing, ensuring that accurate greenhouse gas concentrations can be obtained under different environmental conditions. The real-time data processing capability of the system of the present invention enables the detection results to be quickly fed back, providing timely and accurate information for the monitoring and management of the soil ecological environment.

[0008] In some embodiments, the optical signal transmitting unit includes a laser, the control processing unit is used to send a wavelength adjustment instruction to the laser, and the laser is used to adjust the operating temperature according to the wavelength adjustment instruction to change the wavelength of the detection optical signal.

[0009] The technical solution of the above embodiment provides a method for dynamically adjusting the wavelength of the detection light signal to adapt to the optimal absorption wavelength of different gases. By controlling the processing unit to send a wavelength adjustment instruction to the laser, the laser first pre-adjusts the wavelength by adjusting the operating temperature, and then fine-adjusts the wavelength by adjusting the operating current, ensuring that the wavelength of the detection light signal can accurately match the absorption peak of the target gas. This staged temperature and current adjustment method not only improves the flexibility and accuracy of wavelength adjustment, but also helps to improve the selectivity and sensitivity of gas detection, especially when detecting different types of greenhouse gases, it can achieve more accurate concentration measurement.

[0010] In some embodiments, the laser is specifically used to first adjust the operating temperature according to the wavelength adjustment instruction to pre-adjust the wavelength of the detection light signal, and then adjust the operating current to fine-adjust the wavelength of the detection light signal.

[0011] By adopting the technical solution of the above embodiment, the wavelength of the detection light signal is finely adjusted by precisely controlling the operating temperature and current of the laser. This adjustment method first pre-adjusts the wavelength by adjusting the operating temperature of the laser to quickly approach the target wavelength range, and then fine-tunes the wavelength by fine-tuning the operating current to accurately match the absorption peak of the target gas. This step-by-step adjustment strategy not only improves the efficiency and accuracy of wavelength adjustment, but also helps to reduce the energy consumption of the laser and extend its service life, because excessive temperature adjustment is avoided, thereby reducing the thermal stress on the laser and improving the stability and reliability of the system.

[0012] In some embodiments, the control processing unit is specifically used to input the greenhouse gas concentration and the cavity air pressure into a preset air pressure compensation model to obtain the greenhouse gas detection concentration.

[0013] By adopting the technical solution of the above embodiment, accurate compensation of gas concentration is achieved by inputting greenhouse gas concentration and cavity air pressure data into a preset air pressure compensation model. The control processing unit comprehensively analyzes the photoelectric sensing signal and the data of the air pressure sensor, and performs compensation calculation on the initially measured gas concentration according to the influence of air pressure changes on the density of gas molecules, thereby obtaining the corrected greenhouse gas concentration. This air pressure compensation method not only improves the accuracy of gas detection, but also enables the system to provide consistent measurement results under different ambient air pressure conditions, thereby enhancing the applicability and reliability of the system.

[0014] In some embodiments, a plurality of reflectors are provided in the gas collecting cavity, the optical signal transmitting unit is used to transmit a detection optical signal to the reflector, the reflector is used to reflect the detection optical signal multiple times, and the optical signal receiving unit is used to receive the detection optical signal reflected by the reflector.

[0015] By adopting the technical solution of the above-mentioned embodiment, a plurality of reflectors are arranged in the gas collecting cavity, which significantly increases the propagation path of the optical signal in the gas, thereby improving the sensitivity of gas detection. The optical signal transmitting unit transmits the detection optical signal to the reflector, and the reflector reflects the optical signal multiple times, so that the optical signal makes multiple round trips inside the gas collecting cavity, thereby increasing the opportunity for interaction between the optical signal and the gas molecules. In this way, even when the gas concentration is low, the optical signal receiving unit can detect sufficient changes in light intensity, thereby improving the system's ability to detect low-concentration gases. In addition, this design also helps to reduce the system's dependence on high-power light sources, reduces energy consumption, and can also reduce the gas collecting cavity, thereby achieving a compact system and facilitating portability.

[0016] In some embodiments, the soil ecological environment gas detection system also includes a zero gas unit, which is connected to the gas collecting cavity and is used to introduce zero gas into the gas collecting cavity before the soil gas enters the gas collecting cavity, so as to discharge the original gas in the gas collecting cavity through the zero gas. The zero gas is a gas that does not contain greenhouse gas.

[0017] By adopting the technical solution of the above embodiment, the original gas in the gas collecting cavity is effectively removed by introducing a zero gas unit, ensuring the accuracy and repeatability of each measurement. Before the soil gas enters the gas collecting cavity, the zero gas unit introduces zero gas into the cavity to discharge the original gas. This cleaning process not only removes possible residual gas, but also reduces the risk of cross contamination. The choice of zero gas is also very critical. It should be a gas that does not contain greenhouse gases, such as high-purity nitrogen or synthetic air, to avoid interference with the measurement results. This zero gas cleaning mechanism significantly improves the measurement accuracy of the system and ensures the reliability of data during continuous monitoring.

[0018] In some embodiments, the soil ecological environment gas detection system also includes a gas flow meter, which is connected between the zero gas unit and the gas collecting cavity, and is connected to the control processing unit. The gas flow meter is used to detect the zero gas flow rate, and the control processing unit is used to control the working condition of the zero gas unit according to the zero gas flow rate.

[0019] By adopting the technical solution of the above-mentioned embodiment, a gas flow meter is introduced to achieve precise control of the zero gas flow rate, thereby optimizing the cleaning process of the gas collecting cavity. The gas flow meter is connected between the zero gas unit and the gas collecting cavity, and is connected to the control processing unit for real-time monitoring of the flow rate of the zero gas. The control processing unit dynamically adjusts the working state of the zero gas unit, such as the flow rate or duration, according to the data of the gas flow meter, to ensure that the zero gas can effectively clean the gas collecting cavity without interfering with the measurement results. This intelligent flow control mechanism not only improves the cleaning efficiency, but also helps to reduce energy consumption and reduce the consumption of zero gas, thereby improving the economy and environmental protection of the system.

[0020] In some embodiments, the control processing unit is also used to control the zero gas unit to introduce zero gas into the gas collecting cavity, and determine the dilution ratio of the soil gas according to the amount of zero gas introduced and the volume of the soil gas, and then reduce the greenhouse gas detection concentration according to the dilution ratio to obtain the reduced value of the greenhouse gas detection concentration.

[0021] By adopting the technical solution of the above embodiment, the zero gas unit is precisely controlled to introduce zero gas into the gas collecting cavity, and the dilution ratio of the soil gas is intelligently determined according to the amount of zero gas introduced and the volume of the soil gas. The control processing unit uses this dilution ratio to perform an inverse calculation on the greenhouse gas concentration initially detected, thereby restoring the original gas concentration value before dilution. This intelligent dilution and reduction strategy not only improves the system's ability to measure high-concentration gas samples, but also ensures that accurate detection results can be obtained at various gas concentration levels, significantly improving the accuracy and reliability of detection, which is of great significance for evaluating soil greenhouse gas emissions and conducting related environmental research.

[0022] In some embodiments, the soil ecological environment gas detection system also includes a temperature sensor, which is used to detect the temperature of the target soil and is connected to the control processing unit.

[0023] By adopting the technical solution of the above embodiment, real-time monitoring of the target soil temperature is achieved by introducing a temperature sensor. The temperature sensor is in direct contact with the soil and can accurately capture subtle changes in soil temperature and transmit these data to the control processing unit. Although the soil temperature data is mainly used in this system to record and analyze the thermal conditions of the soil ecological environment, it provides an important environmental parameter for the system, which helps to more fully understand the potential connection between soil gas emissions and ambient temperature. This temperature monitoring mechanism not only improves the environmental adaptability of the system, but also provides valuable data support for soil management and climate change research.

[0024] In some embodiments, the soil ecological environment gas detection system also includes a humidity sensor, which is used to detect the humidity of the target soil and is connected to the control processing unit.

[0025] By adopting the technical solution of the above embodiment, real-time monitoring of the target soil moisture is achieved by introducing a humidity sensor. The humidity sensor is implanted or placed in the soil, and can accurately detect the moisture content of the soil, and transmit these data to the control processing unit in real time. Although the soil moisture data is mainly used to record and analyze the moisture status of the soil ecological environment in this system, it provides another important environmental parameter for the system, which helps to more deeply understand the interaction between soil gas emissions and soil moisture. This humidity monitoring mechanism not only improves the environmental adaptability of the system, but also provides rich data support for soil management and environmental protection.

[0026] One or more technical solutions provided by the present invention have at least the following technical effects or advantages: 1. Improve detection sensitivity and accuracy: The present invention improves the sensitivity and accuracy of soil ecological environment gas detection. By setting multiple reflectors in the gas collecting cavity, the propagation path of the light signal in the gas is increased, thereby increasing the probability of gas molecules absorbing light. This design effectively improves the system's ability to detect low-concentration greenhouse gases, so that accurate detection results can be obtained even when the gas concentration is low. In addition, by precisely controlling the operating temperature and current of the laser, fine adjustment of the wavelength of the detection light signal is achieved, ensuring that the wavelength of the light signal can accurately match the absorption peak of the target gas, further improving the selectivity and sensitivity of gas detection.

[0027] 2. Realize air pressure compensation and dilution reduction: The present invention realizes air pressure compensation and dilution reduction, which improves the accuracy and reliability of gas detection. By integrating an air pressure sensor and a zero gas unit in the system, the air pressure inside the gas collecting chamber and the cleaning chamber are monitored respectively. The system can compensate and restore the initially detected gas concentration according to the air pressure change and the dilution ratio. This air pressure compensation and dilution reduction mechanism not only improves the measurement accuracy of the system under different ambient air pressure conditions, but also ensures that accurate detection results can be obtained under high concentration conditions, significantly improving the applicability and reliability of the system.

[0028] 3. The system is compact and portable: The present invention realizes a compact and portable design of the system. By setting a reflector in the gas collecting cavity to extend the propagation path of the optical signal without increasing the actual length of the cavity, the system achieves a lightweight and compact design while maintaining high sensitivity and accuracy. In addition, by integrating a high-performance control processing unit and various sensors, the system can quickly and accurately detect soil gas in a field environment without the need for complex sampling and laboratory analysis processes. This portable design enables the system to be widely used in on-site monitoring and management of various soil ecological environments, improving monitoring efficiency and flexibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings herein are incorporated into and constitute a part of the specification, showing embodiments consistent with the present invention, and together with the specification, are used to explain the principles of the present invention. Obviously, the drawings described below are only some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work. In the drawings: Figure 1 It is a schematic diagram of the architecture of a soil ecological environment gas detection system according to an embodiment of the present invention; Figure 2 is a schematic diagram of the arrangement of the reflector in the gas collecting cavity in an embodiment of the present invention; Figure 3It is a schematic diagram of the architecture of another soil ecological environment gas detection system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The terms used in the following embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to be limiting of the present invention. As used in the specification of the present invention, the singular expressions "a", "a", "above", "the" and "this" are intended to also include plural expressions, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used in the present invention refers to any or all possible combinations comprising one or more of the listed items.

[0031] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood as implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, unless otherwise specified, the meaning of "plurality" is two or more.

[0032] It should also be noted that, unless otherwise clearly specified and limited, in the embodiments of the present invention, the terms such as "setting" and "connection" should be understood in a broad sense. For example, "connection" 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 a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two components; it can be a wired communication connection or a wireless communication connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. The embodiments of the present invention are described in detail below.

[0033] The embodiment of the present invention provides a soil ecological environment gas detection system, which can improve the timeliness and accuracy of soil ecological environment gas detection through precise control of gas collection, advanced spectral detection technology, air pressure compensation and data processing technology, and provide strong technical support for environmental monitoring and agricultural management.

[0034] like Figure 1 As shown, the soil ecological environment gas detection system of this embodiment includes a gas collection unit 1, a gas collecting cavity 2, an optical signal transmitting unit 31, an optical signal receiving unit 32, an air pressure sensor 4 and a control processing unit 5.

[0035] The gas collection unit 1 is used to collect soil gas in the target soil, where the soil gas contains greenhouse gases.

[0036] Specifically, the gas collection unit 1 collects soil gas through soil probes or sampling tubes installed in the target area. These probes or sampling tubes are designed to be able to penetrate the soil and have built-in small holes or permeable membranes to allow soil gas to pass through; then, these gases are guided into the gas collecting cavity 2. During this process, the gas may be transported to the detection system by pumping or natural diffusion, ensuring that samples containing greenhouse gases are directly and efficiently collected from the soil, providing a reliable basis for subsequent concentration determination.

[0037] Among them, greenhouse gases include but are not limited to carbon dioxide, methane and nitrous oxide.

[0038] The gas collecting cavity 2 is connected to the gas collecting unit 1 and is used to contain soil gas.

[0039] Specifically, the gas collection cavity 2 is a closed container, which is directly connected to the gas collection unit 1, and its main function is to provide a stable and controlled environment to temporarily store soil gas collected from the soil. By ensuring the sealing of the cavity, the gas sample can be prevented from mixing with the outside air or being contaminated, thereby ensuring the accuracy and reliability of the gas concentration measurement. In addition, the design of the gas collection cavity 2 also allows optical signals to pass through it, so that the gas sample in the cavity can be effectively detected by the optical signal transmitting and receiving unit, providing the necessary conditions for subsequent gas concentration analysis.

[0040] The optical signal emitting unit 31 is located at one end of the gas collecting cavity 2 and is used for emitting a detection optical signal.

[0041] Specifically, the optical signal emitting unit 31 is equipped with a high-stability light source, such as a laser diode, which is precisely placed at one end of the gas collecting cavity 2. The function of this unit is to emit detection optical signals of specific wavelengths, which pass through the soil gas in the cavity and detect the type and concentration of the gas based on the absorption characteristics of the gas molecules to the light of specific wavelengths.

[0042] The optical signal receiving unit 32 is located at the other end of the gas collecting cavity 2 and is arranged opposite to the optical signal transmitting unit 31 , and is used to receive the detection optical signal passing through the gas collecting cavity 2 and generate a photoelectric sensing signal.

[0043] The optical signal receiving unit 32 is located at the other end of the gas collecting cavity 2, precisely opposite to the optical signal emitting unit 31. It is equipped with a highly sensitive photoelectric detector for capturing the optical signal after passing through the soil gas. The detector converts the received optical signal into an electrical signal, i.e., a photoelectric sensing signal, whose intensity change is proportional to the concentration of the gas in the cavity. These signals are then sent to the control processing unit 5 for further analysis and processing to determine the exact concentration of greenhouse gases in the soil gas.

[0044] The air pressure sensor 4 is disposed in the gas collecting cavity 2 and is used to detect the cavity air pressure inside the gas collecting cavity 2 .

[0045] Specifically, the air pressure sensor 4 is built into the gas collecting cavity 2, and is responsible for real-time monitoring and recording of the air pressure changes inside the cavity. The air pressure sensor 4 is crucial to ensure the accuracy of gas detection, because the distribution and density of gas molecules will change under different air pressure conditions, thereby affecting the absorption and scattering characteristics of the light signal when passing through the gas.

[0046] The control processing unit 5 is connected to the optical signal receiving unit 32 and the air pressure sensor 4 respectively, and is used to determine the greenhouse gas concentration of the soil gas according to the photoelectric sensing signal, and compensate the greenhouse gas concentration according to the cavity air pressure to obtain the greenhouse gas detection concentration of the target soil.

[0047] Specifically, the control processing unit 5 is responsible for analyzing and processing the photoelectric sensing signal captured by the optical signal receiving unit 32 to determine the concentration of greenhouse gases in the soil gas. The control processing unit 5 can compare the intensity of the received optical signal with the known gas absorption spectrum database to identify and quantitatively analyze the presence and concentration of specific gases. At the same time, the control processing unit 5 also receives pressure data from the air pressure sensor 4 inside the cavity, and dynamically adjusts the original gas concentration data through an advanced air pressure compensation algorithm to eliminate the impact of changes in gas molecule density under different air pressure conditions on the detection results. In this way, the system can accurately calculate the actual concentration of greenhouse gases in the target soil, ensure the accuracy and reliability of the detection results, and provide timely and accurate soil gas data for environmental monitoring and agricultural management.

[0048] This embodiment is based on the principle of spectral absorption and quantitatively analyzes the gas concentration according to the absorption characteristics of specific gas molecules to light of specific wavelengths. In this embodiment, the detection signal light of a specific wavelength emitted by the optical signal emitting unit 31 passes through the gas collecting cavity 2 containing the soil gas to be measured, and the gas molecules therein absorb the light waves that match their molecular structure, resulting in a change in the intensity of the optical signal. The optical signal receiving unit 32 can convert the optical signal into an electrical signal, and the attenuation of the optical signal will also be reflected in the change of the electrical signal. The control processing unit 5 calculates the concentration of the gas molecules according to the attenuation degree of the optical signal using spectral analysis methods such as the Beer-Lambert Law. This method has a high degree of sensitivity and selectivity, can accurately detect greenhouse gases in the soil, and can provide accurate measurement results even when the gas concentration is very low.

[0049] Taking the detection of carbon dioxide as an example, the concentration of carbon dioxide in the soil is detected by utilizing the absorption characteristics of carbon dioxide molecules to light of a specific wavelength, such as in the infrared band of 4.26 microns. When the light wave of the detection light signal passes through the gas in the gas collecting cavity 2, the carbon dioxide molecules absorb the light energy corresponding to their characteristic absorption wavelength, and this absorption causes the intensity of the light signal to weaken. The optical signal receiving unit 32 can convert the optical signal into an electrical signal, and the attenuation of the optical signal will also be reflected in the change of the electrical signal. The control processing unit 5 calculates the concentration of carbon dioxide inside the cavity by analyzing the intensity and wavelength of the absorption spectrum according to the Beer-Lambert law. Since the absorption spectrum of carbon dioxide is known and specific, this method can measure the concentration of carbon dioxide in the soil very accurately and sensitively, and can provide accurate detection results even at low concentrations.

[0050] This embodiment adopts the above-mentioned design, and uses the gas collection unit 1 to directly collect gas samples from the soil, ensuring the directness and real-time nature of the detection. The design of the gas collection cavity 2 ensures the stability of the sample and prevents interference from external gases, further improving the accuracy of the detection. The application of the optical signal transmitting unit 31 and the receiving unit is based on the principle of absorption spectroscopy, and quantitatively analyzes the gas concentration by analyzing the changes in the optical signal passing through the soil gas. This method has high sensitivity and high selectivity. The introduction of the air pressure sensor 4 enables the system to compensate the detection results in real time according to the changes in the air pressure in the cavity, thereby eliminating the influence of air pressure fluctuations on the gas concentration readings and enhancing the accuracy of the measurement results. The control processing unit 5 is the core of the system. It not only processes the photoelectric sensing signal and determines the gas concentration, but also combines the air pressure data for intelligent compensation processing, ensuring that accurate greenhouse gas concentrations can be obtained under different environmental conditions. In addition, the real-time data processing capability of the system enables the detection results to be quickly fed back, providing timely and accurate information for the monitoring and management of the soil ecological environment.

[0051] In this embodiment, the control processing unit 5 is a highly integrated hardware component, which is usually composed of one or more high-performance microprocessors or microcontrollers, and is equipped with sufficient memory and storage space to save operating programs and data records. The control processing unit 5 is connected to peripheral devices such as an optical signal receiving unit, an air pressure sensor, a temperature sensor, a humidity sensor, and a zero air unit in the system through various interfaces, such as digital and analog input and output ports, to achieve data collection, processing, and sending of execution instructions.

[0052] The control processing unit 5 may also have some built-in algorithms and models for real-time analysis of sensor data, control of gas collection and zero gas cleaning processes, and execution of gas pressure compensation calculations, etc. In addition, it may also have a communication interface, such as a wireless network module or Bluetooth, to support remote data transmission, and a user interface, such as a touch screen or LCD display, to facilitate user operation and monitoring of system status.

[0053] In some embodiments, the optical signal transmitting unit 31 includes a laser, and the control processing unit 5 is used to send a wavelength adjustment instruction to the laser, and the laser is used to adjust the operating temperature according to the wavelength adjustment instruction to change the wavelength of the detection optical signal.

[0054] Specifically, the control processing unit 5 sends specific wavelength adjustment instructions to the laser through a pre-compiled software program according to the absorption wavelength of a specific greenhouse gas in the gas absorption spectrum database. These instructions are transmitted through the communication interface between the control processing unit 5 and the laser. After receiving the instructions, the laser adjusts its operating temperature to change the wavelength of the emitted light signal, because the emission wavelength of the laser is closely related to its operating temperature. By accurately controlling the operating temperature of the laser, it is possible to accurately adjust the wavelength of the detected light signal to ensure that the light signal is at the optimal absorption wavelength of the target gas, thereby improving the selectivity and sensitivity of gas detection. This process involves precise temperature control technology and feedback mechanisms to ensure that the laser can quickly and accurately reach the required operating temperature and achieve wavelength adjustment.

[0055] Taking the detection of carbon dioxide (CO2) concentration as an example, the software built into the control processing unit 5 will determine the characteristic absorption wavelength of carbon dioxide based on the absorption spectrum database of CO2, such as the infrared band of 4.26 microns, and then automatically send wavelength adjustment instructions to the laser. After receiving these instructions, the laser adjusts the wavelength of its emitted light signal by changing the operating temperature until it reaches the optimal absorption wavelength of carbon dioxide, ensuring that the light signal can be effectively absorbed by the CO2 molecules. In this way, when the light signal passes through the soil gas sample containing CO2, the light energy of a specific wavelength is absorbed by the CO2 molecules, and the light intensity change detected by the light signal receiving unit 32 is converted into an electrical signal and processed by the control processing unit 5, and finally the precise concentration of CO2 is calculated. This process shows how the system uses the temperature control of the laser to accurately adjust the wavelength of the detection light signal to achieve high-sensitivity detection of specific gases.

[0056] In some embodiments, the laser is specifically used to first adjust the operating temperature according to the wavelength adjustment instruction to pre-adjust the wavelength of the detection light signal, and then adjust the operating current to fine-adjust the wavelength of the detection light signal.

[0057] Specifically, the laser, as an optical signal transmitting unit 31, first adjusts its operating temperature to pre-adjust the wavelength when receiving a wavelength adjustment instruction issued by the control processing unit 5 according to a preset gas absorption spectrum database. This is because the emission wavelength of the laser is directly related to its operating temperature. By accurately controlling the temperature, the laser can change the wavelength of the emitted light to a rough target range. Subsequently, in order to fine-tune the wavelength, the laser will fine-tune its operating current according to further instructions from the control processing unit 5, because changes in the current can cause slight changes in the laser emission wavelength, thereby achieving precise control of the wavelength of the detected optical signal. This two-step adjustment process of coarse first and fine later ensures that the wavelength of the optical signal emitted by the laser can accurately match the absorption peak of the target gas (such as carbon dioxide), thereby improving the selectivity and sensitivity of gas detection.

[0058] The advantage of adopting this step-by-step adjustment strategy in this embodiment is that it combines the wide-range wavelength adjustment capability of temperature adjustment with the fine wavelength control capability of current adjustment, thereby ensuring that the wavelength of the laser-emitted light can be accurately aligned with the gas absorption peak while ensuring the adjustment speed, thereby improving the selectivity and sensitivity of gas detection. In addition, this method also helps to reduce the energy consumption of the laser and extend its service life, because excessive adjustment of the operating temperature can be avoided through fine current adjustment, thereby reducing thermal stress on the laser. This adjustment method improves the performance of the soil ecological environment gas detection system, enabling it to more accurately monitor and analyze the concentration of greenhouse gases.

[0059] In some embodiments, the control processing unit 5 is specifically used to input the greenhouse gas concentration and the cavity air pressure into a preset air pressure compensation model to obtain the greenhouse gas detection concentration.

[0060] Specifically, after receiving the photoelectric sensing signal generated by the optical signal receiving unit 32, the control processing unit 5 first determines the preliminary concentration of greenhouse gases in the soil gas based on the signal intensity and the known absorption spectrum data. Then, the control processing unit 5 inputs this preliminary concentration together with the internal air pressure data of the gas collecting cavity 2 monitored in real time by the air pressure sensor 4 into the preset air pressure compensation model. This model performs compensation calculations on the preliminary concentration based on the gas state equation and the principles of absorption spectroscopy, taking into account the influence of air pressure on the gas molecule density and light absorption coefficient. Through this intelligent data processing, the control processing unit 5 finally obtains the corrected greenhouse gas detection concentration, thereby ensuring the accuracy of the detection results and providing reliable measurement values ​​even under different ambient air pressure conditions.

[0061] In some embodiments, the air pressure compensation model includes an air pressure compensation formula, and the air pressure compensation formula is specifically as follows: ; Among them, C corrected is the concentration of greenhouse gases after compensation; C raw is the original gas concentration without pressure compensation; P is the current pressure inside the chamber; P ref is the reference air pressure, generally taken as standard atmospheric pressure (101.325 kPa); k is an empirical coefficient obtained by fitting experimental data, which reflects the degree of influence of air pressure changes on gas concentration; e is the base of the natural logarithm, which is approximately equal to 2.71828.

[0062] In this embodiment, the pressure compensation formula uses an exponential function to describe the relationship between air pressure and gas concentration. This method can capture the nonlinear behavior of gas molecules under different air pressure conditions. Under high air pressure, the distance between gas molecules is reduced, resulting in enhanced interactions between molecules, which may affect the absorption and scattering of light signals when passing through the gas, and the exponential function can simulate this nonlinear change well. The coefficient k is a key parameter in the model. It combines the physical and chemical properties of the gas and the influence of environmental conditions, so that the compensation calculation can be dynamically adjusted according to the actual measured air pressure data, thereby ensuring that accurate greenhouse gas concentration measurement results can be obtained under different ambient air pressures. In addition, the k value obtained by fitting the experimental data provides empirical verification for the model, enhancing its applicability and reliability in practical applications.

[0063] In some embodiments, Figure 2 As shown, a plurality of reflectors 21 are provided in the gas collecting cavity 2, the optical signal transmitting unit 31 is used to transmit a detection optical signal to the reflector 21, the reflector 21 is used to reflect the detection optical signal multiple times, and the optical signal receiving unit 32 is used to receive the detection optical signal reflected by the reflector 21.

[0064] Specifically, these reflectors 21 work together with the optical signal emitting unit 31 to increase the propagation path of the detection light signal in the soil gas. After entering the gas collecting cavity 2, the detection light signal emitted by the optical signal emitting unit 31 does not propagate in a straight line, but is reflected in sequence by these reflectors 21, so that the light signal is reflected multiple times inside the cavity, increasing the chance of interaction between the light signal and the soil gas. Such a design effectively extends the propagation distance of the light signal and increases the probability of gas molecules absorbing light, thereby enhancing the detection sensitivity of the system. After multiple reflections, the light signal is finally captured by the optical signal receiving unit 32, which converts the received light signal into an electrical signal for subsequent data processing and analysis by the control processing unit 5 to calculate the concentration of greenhouse gases in the soil gas.

[0065] This method of increasing the light path length by using the reflector 21 not only improves the accuracy of detection, but also enables the system to more effectively detect low concentrations of gas, thus meeting the requirements of soil ecological environment gas detection for high sensitivity and high accuracy.

[0066] In this embodiment, the arrangement of the reflectors 21 in the gas collection cavity 2 increases the chances of the detection light signal interacting with the soil gas, because they cause the detection light signal to be reflected multiple times in the cavity, thereby extending the effective propagation path of the light signal in the gas. This design cleverly increases the sensitivity of the light absorption measurement without increasing the actual length of the gas collection cavity, which helps to maintain the compactness of the system, achieve lightweight and compact design, and make the entire system more portable and easy to deploy in various soil ecological environments for gas detection. In this way, the system achieves optimization of size and weight without sacrificing performance, improving its practicality in field operations.

[0067] In some embodiments, Figure 3 As shown, the soil ecological environment gas detection system also includes a zero gas unit 6, which is connected to the gas collecting cavity 2 and is used to introduce zero gas into the gas collecting cavity 2 before the soil gas enters the gas collecting cavity 2, so as to discharge the original gas in the gas collecting cavity 2 through the zero gas, and the zero gas is a gas that does not contain greenhouse effect gases.

[0068] Specifically, the zero gas unit 6 is connected to the gas collection chamber 2, and can introduce zero gas, i.e., a gas that does not contain target greenhouse gases, such as high-purity nitrogen, helium, etc., into the gas collection chamber 2 before the measurement cycle starts or when the soil sample is replaced. This process effectively removes the residual gas in the chamber, ensuring that the chamber is in a clean state before receiving a new soil gas sample.

[0069] In this way, the system is able to eliminate or reduce the interference of gases that may remain in previous measurements on subsequent measurement results, thereby ensuring the accuracy and repeatability of each measurement. The introduction of the Zero Gas Unit 6 significantly improves the measurement accuracy of the system and ensures the reliability of data during continuous monitoring, which is crucial for the accurate assessment of soil greenhouse gas emissions.

[0070] In some embodiments, the soil ecological environment gas detection system also includes a gas flow meter 7, which is connected between the zero gas unit 6 and the gas collecting cavity 2, and is connected to the control processing unit 5. The gas flow meter 7 is used to detect the zero gas flow rate, and the control processing unit 5 is used to control the working condition of the zero gas unit 6 according to the zero gas flow rate.

[0071] Specifically, the gas flow meter 7 is placed on the gas flow channel between the zero gas unit 6 and the gas collecting cavity 2. The function of the gas flow meter 7 is to monitor and record the flow of zero gas through the channel in real time, to ensure that the zero gas enters the gas collecting cavity 2 at an appropriate flow rate, and to effectively remove or replace the original gas in the cavity.

[0072] In addition, the gas flow meter 7 is also connected to the control processing unit 5, so that the system can dynamically adjust the working state of the zero gas unit 6, such as the flow rate or duration, according to the monitored zero gas flow data to optimize the cleaning efficiency of the cavity and ensure the accuracy of the measurement.

[0073] This intelligent flow control mechanism not only improves the system's operational convenience, but also helps reduce measurement errors caused by gas residue or cross-contamination, thereby ensuring high accuracy and consistency of data during continuous monitoring.

[0074] In some embodiments, the control processing unit 5 is also used to control the zero gas unit 6 to introduce zero gas into the gas collecting cavity 2, and determine the dilution ratio of the soil gas according to the amount of zero gas introduced and the volume of the soil gas, and then reduce the greenhouse gas detection concentration according to the dilution ratio to obtain the reduced value of the greenhouse gas detection concentration.

[0075] This embodiment takes into account that in some cases the concentration of greenhouse gases is too high, which may cause the light signal to attenuate excessively when passing through the gas collecting cavity 2, causing the photoelectric signal generated by the light signal receiving unit 32 to be too low, affecting the detection accuracy of the light signal receiving unit 32. Therefore, the control processing unit 5 controls the zero gas unit 6 to pass zero gas into the gas collecting cavity 2 to dilute the high-concentration soil gas sample and reduce the excessive attenuation of the detection light signal. In this way, the control processing unit 5 can accurately monitor and calculate the ratio of the zero gas intake to the original volume of the soil gas, thereby determining the dilution ratio of the soil gas.

[0076] The control processing unit 5 then uses this dilution ratio to perform an inverse calculation on the initially detected high-concentration greenhouse gas through an algorithm to restore the original gas concentration value before dilution. This intelligent restoration process ensures that the system can provide accurate and reliable greenhouse gas detection results even under high-concentration conditions, significantly improving the accuracy and reliability of detection.

[0077] In some embodiments, the soil ecological environment gas detection system further includes a temperature sensor 8 , which is used to detect the temperature of the target soil and is connected to the control processing unit 5 .

[0078] Specifically, the temperature sensor 8 can be arranged on the gas collection unit 1, and inserted into the target soil together with the gas collection unit 1, for real-time monitoring of the temperature condition of the target soil. This temperature sensor 8 is directly in contact with the soil, and can accurately capture the slight changes in the soil temperature, and transmit these data to the control processing unit 5.

[0079] Soil temperature data can be used to record and analyze the thermal conditions of the soil ecological environment to obtain more comprehensive ecological information, and analyze the thermal conditions of the soil ecological environment to obtain more comprehensive ecological information.

[0080] In some embodiments, the soil ecological environment gas detection system also includes a humidity sensor 9 , which is used to detect the humidity of the target soil and is connected to the control processing unit 5 .

[0081] Specifically, the humidity sensor 9 can be arranged on the gas collection unit 1, and inserted into the target soil together with the gas collection unit 1, so as to monitor the humidity level of the target soil in real time. By implanting or placing the humidity sensor 9 in the soil, the system can accurately detect the moisture content of the soil and transmit these data to the control processing unit 5 in real time. The measurement of soil moisture can be used to record and analyze the moisture status of the soil ecological environment, and provide a comprehensive ecological environment data record.

[0082] By collecting moisture data, researchers can gain a deeper understanding of the interaction between soil gas emissions and soil moisture, thereby providing richer environmental information for soil management and environmental protection.

[0083] The soil ecological environment gas detection system of the embodiment of the present invention provides a method for accurately and timely detecting the concentration of greenhouse gases in the soil through a series of precise components and control processes. The system first collects the gas in the soil through the gas collection unit 1, and then uses the gas collection cavity 2 to contain these gas samples. The optical signal transmitting unit 31 and the optical signal receiving unit 32 are used in conjunction with each other to measure the absorption spectrum of the gas sample by emitting and receiving optical signals of specific wavelengths, thereby determining the concentration of greenhouse gases therein.

[0084] The innovation of this embodiment is that, by integrating the air pressure sensor 4, the air pressure changes inside the gas collecting cavity 2 can be monitored in real time, and these data are used for compensation processing to eliminate the influence of air pressure fluctuations on the gas concentration reading. The control processing unit 5 is the core of the system. It not only processes the photoelectric sensing signal to determine the gas concentration, but also combines the cavity air pressure data and applies the preset air pressure compensation model to calculate the detection concentration of greenhouse gases in the target soil.

[0085] Further innovations include using a laser as the optical signal emitting unit 31, whose wavelength can be adjusted by the command of the control processing unit 5 to optimize the wavelength of the detected optical signal and improve the sensitivity and selectivity of the detection. In addition, the system may also include multiple reflectors 21 to increase the path length of the optical signal in the gas collecting cavity 2, thereby improving the accuracy of the detection.

[0086] This embodiment also designs a zero gas unit 6, which is used to clean the gas collection cavity 2 with zero gas before detection, ensuring that there is no residual gas in the cavity and improving the accuracy of detection. The addition of a gas flow meter 7 enables the system to accurately control the flow of zero gas, further ensuring the effect of zero gas cleaning.

[0087] In addition, the present embodiment further includes a temperature sensor 8 and a humidity sensor 9 for monitoring the environmental conditions of the target soil and providing these data to the control processing unit 5 for more comprehensive data compensation and analysis. Through these innovative and sophisticated control processes, the system of the present invention can provide accurate and timely soil gas detection results, providing powerful technical support for environmental monitoring and agricultural management.

[0088] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A soil ecological environment gas detection system, characterized in that: include: A gas collection unit, used for collecting soil gas in target soil, wherein the soil gas contains greenhouse effect gases; A gas collecting cavity, connected to the gas collecting unit, and used to contain the soil gas; An optical signal emitting unit, located at one end of the gas collecting cavity, for emitting a detection optical signal; an optical signal receiving unit, located at the other end of the gas collecting cavity, arranged opposite to the optical signal transmitting unit, and used for receiving the detection optical signal passing through the gas collecting cavity and generating a photoelectric sensing signal; An air pressure sensor is disposed in the gas collecting cavity and is used to detect the cavity air pressure inside the gas collecting cavity; A control processing unit is connected to the optical signal receiving unit and the air pressure sensor, respectively, and is used to determine the greenhouse gas concentration of the soil gas according to the photoelectric sensing signal, and to compensate the greenhouse gas concentration according to the cavity air pressure to obtain the greenhouse gas detection concentration of the target soil.

2. The soil ecological environment gas detection system according to claim 1 is characterized in that: The optical signal transmitting unit includes a laser, the control processing unit is used to send a wavelength adjustment instruction to the laser, and the laser is used to adjust the operating temperature according to the wavelength adjustment instruction to change the wavelength of the detection optical signal.

3. The soil ecological environment gas detection system according to claim 2 is characterized in that: The laser is specifically used to first adjust the operating temperature according to the wavelength adjustment instruction to pre-adjust the wavelength of the detection light signal, and then adjust the operating current to fine-adjust the wavelength of the detection light signal.

4. The soil ecological environment gas detection system according to claim 1 is characterized in that: The control processing unit is specifically used to input the greenhouse gas concentration and the cavity air pressure into a preset air pressure compensation model to obtain the greenhouse gas detection concentration.

5. The soil ecological environment gas detection system according to claim 1, characterized in that: A plurality of reflectors are arranged in the gas collecting cavity, the optical signal transmitting unit is used to transmit the detection optical signal to the reflector, the reflector is used to reflect the detection optical signal multiple times, and the optical signal receiving unit is used to receive the detection optical signal reflected by the reflector.

6. The soil ecological environment gas detection system according to claim 1, characterized in that: It also includes a zero gas unit, which is connected to the gas collecting cavity and is used to introduce zero gas into the gas collecting cavity before the soil gas enters the gas collecting cavity, so as to discharge the original gas in the gas collecting cavity through the zero gas, and the zero gas is a gas that does not contain the greenhouse effect gas.

7. The soil ecological environment gas detection system according to claim 6, characterized in that: It also includes a gas flow meter, which is connected between the zero gas unit and the gas collecting cavity and is connected to the control processing unit. The gas flow meter is used to detect the zero gas flow rate, and the control processing unit is used to control the working condition of the zero gas unit according to the zero gas flow rate.

8. The soil ecological environment gas detection system according to claim 7, characterized in that: The control processing unit is also used to control the zero gas unit to introduce zero gas into the gas collecting cavity, and determine the dilution ratio of the soil gas according to the introduction amount of the zero gas and the volume of the soil gas, and then reduce the greenhouse gas detection concentration according to the dilution ratio to obtain the reduced value of the greenhouse gas detection concentration.

9. The soil ecological environment gas detection system according to claim 1, characterized in that: It also includes a temperature sensor, which is used to detect the temperature of the target soil and is connected to the control processing unit.

10. The soil ecological environment gas detection system according to claim 1, characterized in that: It also includes a humidity sensor, which is used to detect the humidity of the target soil and is connected to the control processing unit.

Images