Gas concentration measuring device and method

Abstract

The application discloses a kind of gas concentration measuring device and method, belong to gas analysis field.The device is by changing each function module in its main structure to realize integrated detection trace gas.Gas path module imports the main control cavity of sample detection module to the gas to be measured in environment;Light path module projects spectrum to medium grating metal film sensor.The sensor utilizes the silicon structure grating of specific mathematical formula that is accurately matched about hierarchical margin geometric size relationship, excites high sensitivity surface plasmon wave, forms reflected spectrum attenuation and resonance peak effect, by the extracted zero order diffraction angle fluctuation is monitored using coefficient of variation to control boundary to be stable dynamically automatically determined, finally joint the preset sensitivity MAP chart in cloud database reverse calculation corresponding gas refractive index offset, and then parse accurate environment concentration.The scheme solves the short board that conventional optical equipment large-scale is difficult to deploy, improves the portability of equipment and the efficiency of analysis.

Description

Technical Field

[0001] This application relates to the field of gas analysis technology, and in particular to a gas concentration measuring device and method. Background Technology

[0002] Existing gas refractive index sensor technologies primarily utilize traditional optical interferometry methods such as Michelson interferometers and fiber cavity interferometers. These devices are bulky and have complex optical path adjustments. Furthermore, their sensitivity for detecting trace amounts of gas is insufficient. Sensors employing surface plasmon resonance (SPR) technology offer higher detection sensitivity, but their over-reliance on prism coupling mechanisms and complex optical alignment steps hinder miniaturization and integration. While photonic crystal sensors possess miniaturization potential, they suffer from a bottleneck of less than 70% light transmittance, severely limiting detection efficiency.

[0003] The demand for gas analysis devices is surging in industrial gas detection, formaldehyde monitoring in residential environments (requiring multiple, flexible deployments), and early screening of patients using breathalyzers (with extremely high requirements for cleanliness and rapid detection response). However, in complex communication environments such as mines, there is a contradiction between signal shielding and insufficient computing power for data processing. Therefore, existing detection technologies cannot meet the core requirements of high precision, miniaturization, rapid multimodal analysis, and stable computation in weak network environments. Summary of the Invention

[0004] To address the shortcomings of existing gas detection devices, such as large size, complex optical alignment making them difficult to carry, and slow data processing and inaccurate measurements due to insufficient computing power in complex scenarios with weak communication signals, this application provides a gas concentration measurement device and method, specifically involving a gas concentration measurement device and testing method based on the surface plasmon resonance effect.

[0005] According to one aspect of the embodiments of this application, a gas concentration measuring device is provided, the gas concentration measuring device including a main structure, and a gas path module, an optical path module, a sample detection module and a data processing module disposed within the main structure; The main structure is provided with opposite air inlets and exhaust outlets; The air inlet of the gas path module is in fluid communication with the air inlet, the exhaust of the gas path module is in fluid communication with the air inlet of the sample detection module, and the exhaust port of the sample detection module is in fluid communication with the exhaust outlet. The sample detection module has an aqueous solution capable of dissolving the target gas, and the refractive properties of the aqueous solution are related to the concentration of the target gas. The optical path module includes a light wave generator and a light wave receiver, which are located on opposite sides of the sample detection module. The light wave generator is used to emit light waves into the aqueous solution, and the light wave receiver is used to receive the light waves reflected by the aqueous solution and generate reflection spectral data, as well as transmit the reflection spectral data to the data processing module. The data processing module is used to send the reflectance spectral data to the cloud data analysis center, and to receive the return data from the cloud data analysis center and output the target gas concentration result based on the return data.

[0006] In an exemplary embodiment, the sample detection module includes a dielectric grating metal thin film sensor and an interface device. The dielectric grating metal thin film sensor includes, in sequence along the incident direction of the light wave, an aqueous solution detection layer for dissolving the target gas, a dielectric grating layer, a metal thin film layer, and a dielectric substrate. The light wave emitted by the optical path module excites surface plasmon waves between the target gas aqueous solution detection layer and the metal thin film layer to generate a resonance peak in the reflection spectrum.

[0007] In an exemplary embodiment, the dielectric grating layer is a silicon grating structure, which includes a plurality of arrayed grating units. The length of the short side of each grating unit is set to x, the length of the long side is set to y, the distance between the long side and the short side is set to z, and the distance from the midpoint of the arc to the short side is set to k. The structural parameters are set to satisfy the following relationship: (1) (2) (3) (4) in, The period of the grating structure is given. The structure factor is in the range of 0.7 to 0.8.

[0008] In an exemplary embodiment, the gas path module is provided with an intake turbine, an air filter and an air flow meter in sequence along the airflow direction; the aqueous solution detection layer is filled with the aqueous solution containing pure water and a specific gas absorption reagent; the air containing the target gas enters through the air inlet of the interface device after the air flow meter measures the intake volume; the remaining gas after the target gas dissolves in the aqueous solution is discharged through the exhaust port.

[0009] In an exemplary embodiment, the light wave generator operates through continuous small increments. The dielectric grating metal thin film sensor is scanned by varying the incident angle θ, where the incident angle θ is in the range of -90°. o Up to 90 o .

[0010] In an exemplary embodiment, a motor module is further provided within the main structure. The motor module is connected to a rotating standard interface at the bottom of the main structure. The rotating standard interface is used to connect to a fixing device. The motor module is used to drive the main structure to have a predetermined rotational angular velocity relative to the fixing device in the measurement environment. The data processing module is also used to: stop the operation of the motor module when it is detected that the zero-order diffraction angle in multiple consecutive sets of reflection spectral data stops changing or reaches a stable state.

[0011] In an exemplary embodiment, the data processing module includes a data storage unit integrated on a circuit board, a central data processor, and a data transmitter and receiver; the data processing module is configured as follows: In response to the light wave reflected by the aqueous solution, the resonance peak and its corresponding zero-order diffraction angle in the reflection spectrum are extracted to obtain the reflection spectrum data; When the communication signal reaches a first signal strength, the data transmitter and receiver are driven to send a copy of the reflection spectral data to the cloud data analysis center to determine the target gas concentration result. If the communication signal does not reach the first signal strength, a first target gas sensitivity distribution model, which characterizes the refractive index difference and the zero-order diffraction angle difference, is downloaded from the cloud data analysis center, and the target gas concentration is determined based on the reflection spectral data and the first target gas sensitivity distribution model.

[0012] According to one aspect of the embodiments of this application, a gas concentration measurement method is provided, characterized in that the gas concentration measurement method is implemented based on a gas concentration measurement system, the gas concentration measurement system including a cloud data analysis center and a gas concentration measurement device as described in any of the above embodiments, and the gas concentration measurement method includes: The cloud-based data analysis center pre-sets the initial refractive index of the aqueous solution. and initial zero-order diffraction angle ; The gas concentration measuring device activates the gas path module to collect gas, so that air carrying the target gas enters the sample detection module and the aqueous solution absorbs the target gas; The gas concentration measuring device controls the optical path module to scan the dielectric grating metal thin film sensor in the sample detection module by changing the incident angle θ, records the resonance peak generated when the reflectivity decreases due to surface plasmon wave coupling, and calculates the corresponding real-time zero-order diffraction angle. The reflection spectral data are obtained. The gas concentration measuring device measures multiple consecutive sets of the real-time zero-order diffraction angles. When significant changes cease and a stable state is reached, the gas circuit module stops collecting gas. The cloud-based data analysis center determines the real-time zero-order diffraction angle. With the initial zero-order diffraction angle The zero-order diffraction angle difference is obtained and mapped onto a preset second target gas sensitivity distribution model to obtain the real-time refractive index of the aqueous solution after absorbing the target gas. ; The cloud data analysis center or the gas concentration measuring device uses the real-time refractive index... relative to the initial refractive index The target gas concentration is determined by measuring the refractive index variation and the intake volume measured by the gas path module.

[0013] In an exemplary embodiment, the consecutive sets of the real-time zero-order diffraction angles The criteria for determining whether significant changes have ceased and a steady state has been reached are: Determine the real-time zero-order diffraction angle The coefficient of variation error R is used to determine the real-time zero-order diffraction angle when the coefficient of variation error R does not exceed 5%. Once significant changes cease and a steady state is reached, sampling is complete. The calculation method for the coefficient of variation error satisfies the following relationship: (5) (6) in, For real-time zero-order diffraction angle coefficient of variation, For real-time zero-order diffraction angle The average value of the measurement results This is a single measurement result. To measure the total number of times, The effective value of the coefficient of variation refers to the coefficient of variation from the first measurement cycle to the current measurement cycle. The average value, For the current measurement period Compared with the previous measurement period The difference.

[0014] In an exemplary embodiment, the gas concentration measurement method further includes: When the communication signal does not reach the first signal strength, the gas concentration measuring device downloads a first target gas sensitivity distribution model from the cloud data analysis center, which characterizes the refractive index difference and the zero-order diffraction angle difference of the target gas, and determines a first gas concentration result based on the reflection spectrum data and the first target gas sensitivity distribution model; wherein, the first target gas sensitivity distribution model is a standard data chart under preset temperature and pressure conditions in a standard environment, and the first gas concentration result is a measurement result determined based on the preset temperature and pressure conditions; When the communication signal reaches a first signal strength, the gas concentration measuring device sends a copy of the reflectance spectral data to the cloud data analysis center to determine the target gas concentration result based on the second target gas sensitivity distribution model; wherein, the second target gas sensitivity distribution model includes reference data corresponding to the actual temperature and pressure conditions of the measurement environment, and the target gas concentration result is a measurement result corrected according to the actual temperature and pressure conditions.

[0015] According to one aspect of the embodiments of this application, a computer device is provided, the computer device including a processor and a memory, the memory storing at least one instruction, at least one program, code set or instruction set, the at least one instruction, the at least one program, the code set or instruction set being loaded and executed by the processor to implement the gas concentration measurement device and / or the gas concentration measurement method on the cloud data analysis center side.

[0016] According to one aspect of the embodiments of this application, a computer-readable storage medium is provided, wherein at least one instruction, at least one program, code set, or instruction set is stored in the storage medium, wherein the at least one instruction, the at least one program, the code set, or the instruction set is loaded and executed by a processor to implement the gas concentration measurement method of the above-described gas concentration measurement device and / or cloud data analysis center.

[0017] According to one aspect of the embodiments of this application, a computer program product is provided, the computer program product including computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, causing the computer device to perform actions to implement the gas concentration measurement method described above for the gas concentration measurement device and / or the cloud data analysis center side.

[0018] The technical solution provided in this application can bring the following beneficial effects: In summary, the technical solution provided in this application embodiment involves a gas concentration measuring device that uses an optical path module to detect the refractive properties of an aqueous solution in a sample detection module capable of absorbing the target gas in the measurement environment. The data processing module then uploads the reflection spectrum data detected by the optical path module through photoelectric conversion to a cloud data analysis center for processing. The cloud data analysis center returns data that can assess the concentration of the target gas based on the reflection spectrum data. Consequently, the data processing module can output the target gas concentration result calculated by the cloud data analysis center. This innovatively achieves a separation mechanism between offline spectral measurement by the gas concentration measuring device and online database lookup (sensitivity MAP graph calculation) by the cloud data analysis center. This allows the local gas concentration measuring device to focus solely on photoelectric conversion, significantly reducing the power consumption and size of the gas concentration measuring device.

[0019] The technical solution provided in this application improves sensitivity through sensor structure innovation. By precisely defining the topological parameters (specific mapping relationship x, y, z, k) of the dielectric grating layer, accurate modulation of incident light by the surface structure is achieved. Even with extremely small changes in the refractive index of the target gas (such as a change of 0.001), it exhibits high angular sensitivity (exceeding 500°). o The RIU (Integrated Radio-Instrument) eliminates the need for complex prism optical alignment mechanisms, achieving high precision and miniaturization of the instrument.

[0020] The technical solution provided in this application provides a breakthrough by introducing a coefficient of variation error evaluation model based on the zero-order diffraction angle measurement results, which controls the error R to within 5%. It can automatically determine the saturation physical extreme point of dynamic absorption of gas solution, avoiding the detection error of traditional manual setting of fixed sampling time. It is especially suitable for environments where the concentration of formaldehyde in home and medical breath changes rapidly, improving the accuracy of testing and anti-interference ability.

[0021] The technical solution provided in this application embodiment ensures the continuous effectiveness of analysis and measurement even in extreme environments through weak network communication or by using a local database copy as a backup. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1a A perspective view of the main structure of a gas concentration measuring device provided in an embodiment of this application; Figure 1b A schematic diagram of the microstructure of a dielectric grating metal thin film sensor provided in an embodiment of this application; Figure 2a This is a schematic diagram illustrating the testing working principle of the gas path module and sample detection module provided in the embodiments of this application; Figure 2b This is the zero-order diffraction angle resonance peak curve of reflectivity as a function of incident angle provided in the embodiments of this application; Figure 2c This is a locally magnified curve of the zero-order diffraction angle shift under different refractive indices of the target gas aqueous solution detector layer provided in the embodiments of this application; Figure 2d This is a MAP diagram showing the difference in refractive index and the difference in zero-order diffraction angle of the target gas sensitivity provided in the embodiments of this application; Figure 2e This is a MAP empirical fitting diagram of the refractive index of the target gas aqueous solution and the concentration of the target gas provided in the embodiments of this application. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0025] Please refer to Figure 1a and Figure 1b , Figure 1a This is a perspective view of the main structure of a gas concentration measuring device provided in an embodiment of this application. Figure 1b This is a schematic diagram of the microstructure of a dielectric grating metal thin film sensor provided in an embodiment of this application. The gas concentration measuring device includes a main structure 1 and a gas path module 15, an optical path module 16, a sample detection module 17, and a data processing module 18 disposed within the main structure 1. In some embodiments, the main structure 1 may also include a display module 11, an interface module, a power supply module 13, and a motor module 14.

[0026] The main structure 1 is provided with opposing air inlets 123 and exhaust outlets 124. The air inlets 123 and exhaust outlets 124 are respectively located on the front and rear sides of the main structure 1, for connecting the air intake device and the exhaust device. In this embodiment, the air inlet 123 facing the main structure 1 is taken as the front side, and the air inlet 123 is located on the front of the main structure 1. Correspondingly, the exhaust outlet 124 is located on the rear side of the main structure 1.

[0027] The air inlet of the gas path module 15 is fluidly connected to the air inlet 123, the air outlet of the gas path module 15 is fluidly connected to the air inlet of the sample detection module 17, and the air outlet of the sample detection module 17 is fluidly connected to the air outlet 124. Thus, air from the measurement environment can enter the gas path module 15 inside the main structure 1 through the air inlet 123, and under the guidance of the gas path module 15, enter the sample detection module 17 for gas analysis. Remaining air can also flow out of the main structure 1 from the air outlet 124.

[0028] The sample detection module 17 contains an aqueous solution capable of dissolving the target gas. The refractive properties of the aqueous solution are related to the concentration of the target gas. When air from the measurement environment enters the sample detection module 17, it comes into contact with the aqueous solution within the module. The aqueous solution dissolves the target gas in the air, thereby altering its refractive properties. By detecting these properties, the concentration of the target gas can be determined.

[0029] The optical path module 16 includes a light wave generator 161 and a light wave receiver 162, which are located on opposite sides of the sample detection module 17. The light wave generator 161 is used to emit light waves into the aqueous solution, and the light wave receiver 162 is used to receive the light waves reflected by the aqueous solution and generate reflection spectral data, as well as transmit the reflection spectral data to the data processing module 18.

[0030] The light wave generator 161 and the light wave receiver 162 are respectively disposed inside the main structure 1 at the middle and rear sides. The light wave generator 161 is used to emit light waves of a specific frequency, and the light wave receiver 162 is used to receive and detect the reflection spectrum of the light waves.

[0031] After the aqueous solution absorbs the target gas, its refractive properties change. The optical path module 16 can detect and generate reflection spectral data that can characterize the refractive properties of the aqueous solution by emitting light waves and receiving the light waves reflected by the sample detection module 17.

[0032] The data processing module 18 is used to send reflectance spectral data to the cloud data analysis center, and to receive the return data from the cloud data analysis center and output the target gas concentration result based on the return data. The data processing module 18 has an embedded memory and processor, and executes a calculation separation mechanism of "local end acquisition of reflectance spectrum - cloud data center analysis and comparison of MAP map".

[0033] In summary, the technical solution provided in this application embodiment involves a gas concentration measuring device that uses an optical path module to detect the refractive properties of an aqueous solution in a sample detection module capable of absorbing the target gas in the measurement environment. The data processing module then uploads the reflection spectrum data detected by the optical path module through photoelectric conversion to a cloud data analysis center for processing. The cloud data analysis center returns data that can assess the concentration of the target gas based on the reflection spectrum data. Consequently, the data processing module can output the target gas concentration result calculated by the cloud data analysis center. This innovatively achieves a separation mechanism between offline spectral measurement by the gas concentration measuring device and online database lookup (sensitivity MAP graph calculation) by the cloud data analysis center. This allows the local gas concentration measuring device to focus solely on photoelectric conversion, significantly reducing the power consumption and size of the gas concentration measuring device.

[0034] In an exemplary embodiment, the sample detection module 17 includes a dielectric grating metal thin film sensor 171 and an interface device 172. The sample detection module 17 is disposed on the rear side of the air flow meter 153 and between the light wave generator 161 and the light wave receiver 162.

[0035] The dielectric grating metal thin film sensor 171 includes, in sequence along the incident direction of the light wave, an aqueous solution detection layer 1711 for dissolving the target gas, a dielectric grating layer 1712, a metal thin film layer 1713, and a dielectric substrate 1714; the light wave emitted by the optical path module 16 excites surface plasma waves between the target gas aqueous solution detection layer 1711 and the metal thin film layer 1713 to generate resonance peaks in the reflection spectrum.

[0036] In one possible implementation, the dielectric grating metal thin-film sensor 171 comprises four different structures according to the incident direction of the electromagnetic waves emitted by the light generator 161: the aforementioned aqueous detection layer 1711 (DL), dielectric grating layer 1712 (DGL), metal thin-film layer 1713 (ML), and media substrate 1714 (MS). The DL is filled with an aqueous solution; for example, in formaldehyde detection, it internally encapsulates a mixture of pure water and 0.25% acetylacetone as an absorption solution.

[0037] The DGL is composed of silicon (Si). In an exemplary embodiment, the dielectric grating layer 1712 is a silicon grating structure, which includes multiple arrayed grating units.

[0038] like Figure 1b As shown, the above-mentioned grating unit is roughly in the shape of a circular arc trapezoid. The circular arc connecting the short side and the long side of the circular arc trapezoid is composed of two circular arcs, and the point connecting the two circular arcs is the midpoint of the arc.

[0039] It should be noted that the dimensions shown in the diagram are not the actual dimensions. Because the metal film layer is thin, drawing the image according to the actual scale would make it indistinguishable.

[0040] The length of the short side of the aforementioned grating unit is set as x, the length of the long side is set as y, the distance between the long and short sides is set as z, and the distance from the midpoint of the arc to the short side is set as k. Since the wave source excites surface plasmon polaritons (SPWs) upon reaching the detection metal film, the incident light wave vector matches the wave vector of the reflected SPW, resulting in strong energy coupling and the generation of a resonance peak (RP). To enhance the change in RP value caused by the minute refractive index change of the aqueous solution in the target gas aqueous solution detector layer 1711, i.e., to increase the angular sensitivity, the size ratios of x, y, z, and k need to be precisely set.

[0041] In this embodiment of the application, the above-mentioned structural parameters satisfy the following relationship: (1) (2) (3) (4) in, The period of the grating structure, The structure factor is in the range of 0.7 to 0.8. In this embodiment, It is 820nm.

[0042] This size ratio allows incident light to pass directly through the grating diffraction vector compensation without a prism, achieving high-confidence momentum matching of the surface plasmon wave. The technical solution provided in this application improves sensitivity through sensor structure innovation. By precisely defining the topological parameters of the dielectric grating layer (specific mapping relationships x, y, z, k), accurate modulation of incident light by the surface structure is achieved. Even with extremely small changes in the refractive index of the target gas (such as a change of 0.001), it exhibits high angular sensitivity (exceeding 500°). o The RIU (Integrated Radio-Instrument) eliminates the need for complex prism optical alignment mechanisms, achieving high precision and miniaturization of the instrument.

[0043] The ML is required to have good plasma resonance characteristics. In this embodiment, the ML is composed of silver (Ag).

[0044] The aforementioned light wave generator 161 can transmit light through continuous small increments. The dielectric grating metal thin film sensor 171 is scanned by varying the incident angle θ, with the incident angle θ ranging from -90°. o Up to 90 o .

[0045] The aforementioned interface device 172 includes an air inlet, an exhaust outlet, an incident light area, and a transmitted light area. The incident light area and the transmitted light area are respectively located on the front and rear sides of the dielectric grating metal thin film sensor 171. The air inlet and the exhaust outlet are respectively located on the side and top surface of the dielectric grating metal thin film sensor 171, so that the air path and the light path are perpendicular and do not interfere with each other.

[0046] In an exemplary embodiment, the aforementioned air path module 15 is provided with an intake turbine 151, an air filter 152, and an air flow meter 153 arranged sequentially along the airflow direction. The intake turbine 151, air filter 152, and air flow meter 153 are arranged closely in sequence according to the airflow direction. The filter is responsible for blocking large dust particles. The intake turbine 151 is driven by its matching motor.

[0047] The aqueous detection layer 1711 is filled with an aqueous solution containing pure water and a specific gas absorption reagent. Air containing the target gas enters through the air inlet of the interface device 172 after the air flow meter 153 measures the air intake. The remaining gas after the target gas dissolves in the aqueous solution is discharged through the exhaust port.

[0048] The display module 11 includes a display screen 111 and a touch / mechanical composite control port 112. The display screen 111 may be an LCD display. The display module 11 is located on the side of the main structure 1 and is used for manual operation and reading the target gas concentration results.

[0049] The aforementioned air inlet 123 and exhaust outlet 124 may be part of the aforementioned interface module. The interface module includes a power and data standard interface 121, a rotary standard interface 122, an air inlet 123, and an exhaust outlet 124. The power and data standard interface 121 is located on the rear side of the main body structure 1 and is used for connecting to an external power source and for wired data reading. The rotary standard interface 122 is located on the lower side of the main body structure 1 and is used to connect the fixing device to the main body structure 1.

[0050] The power module 13 includes a 12V removable lithium battery module 131, a charging device 132, and a multi-power supply interface 133. The power module 13 is located on the lower rear side of the main structure 1 to meet the power requirements of the main structure.

[0051] In an exemplary embodiment, a motor module 14 is further provided within the main body structure 1. The motor module 14 includes a stepper motor 141 and a reduction gear set 142. The motor module 14 is disposed on the lower middle side of the main body structure 1, and is connected to a rotating standard interface 122 at the bottom of the main body structure 1. The rotating standard interface 122 is used to connect a fixing device.

[0052] The motor module 14 is used to drive the main body structure 1 to have a predetermined rotational angular velocity relative to the fixed device in the measurement environment. Under the set rotation parameters, the motor module 14 cooperates to enable the main body structure 1 to perform sweeping air intake sampling above the tripod.

[0053] Accordingly, the data processing module 18 is also used to stop the operation of the motor module 14 when it is detected that the zero-order diffraction angle in multiple consecutive sets of reflection spectral data has stopped changing or reached a stable state.

[0054] The aforementioned fixing device can be a tripod that can support the main structure 1. The main structure 1 is placed in the center of the environment to be measured by rotating the tripod to uniformly absorb the gas in the measurement space for analysis.

[0055] One embodiment of this application also provides a gas concentration measurement method, which is based on a gas concentration measurement system. The gas concentration measurement system includes a cloud data analysis center and the aforementioned gas concentration measurement device. The gas concentration measurement method includes the following steps: S11, The cloud data analysis center pre-sets the initial refractive index of the aqueous solution. and initial zero-order diffraction angle .

[0056] In the pre-deployment preparation phase: the gas concentration measuring device is placed in a suitable location in the environment to be tested, and the cloud data analysis center sends the initial refractive index of the aqueous solution used in the current test to the gas concentration measuring device. And the initial zero-order diffraction angle (ZDA) .

[0057] S12. The gas concentration measuring device starts the gas path module 15 to collect gas, so that the air carrying the target gas enters the sample detection module 17 and the aqueous solution absorbs the target gas.

[0058] During the sampling initiation phase: the gas concentration measuring device rotates at a set angular velocity. Intake rate The intake turbine 151 draws in air, and the air filter 152 filters out impurities. The remaining air then enters the aqueous solution detection layer 1711 through the interface device 172. The target gas is absorbed and dissolved by the aqueous solution, and the remaining gas is discharged. (See details...) Figure 2a , Figure 2a This is a schematic diagram illustrating the testing working principle of the gas path module and sample detection module provided in the embodiments of this application.

[0059] S13. The gas concentration measurement device control optical path module 16 scans the dielectric grating metal thin film sensor 171 in the sample detection module 17 by changing the incident angle θ, records the resonance peak generated when the reflectivity decreases due to surface plasmon wave coupling, and calculates the corresponding real-time zero-order diffraction angle. The reflection spectral data were obtained.

[0060] During the full incident angle scanning phase: the light generator 161 uses continuous small increments... The dielectric grating metal thin film sensor 171 is scanned by varying the incident angle θ, with the incident angle θ ranging from -90°. o Up to 90 o When the wave source reaches the detection metal film of the metal thin film layer 1713, it excites surface plasmon polaritons (SPWs). The wave vector of the incident light matches the wave vector of the reflected light SPW, and the energy is strongly coupled to produce a resonance peak (RP). The light wave receiver 162 measures the corresponding real-time zero-order diffraction angle. For details, please refer to Figure 2b , Figure 2b This is the zero-order diffraction angle resonance peak curve of reflectivity as a function of incident angle, provided in the embodiments of this application.

[0061] S14. The gas concentration measuring device measures multiple consecutive sets of real-time zero-order diffraction angles. When significant changes cease and a stable state is reached, gas collection by gas circuit module 15 is stopped.

[0062] During the dynamic determination of the absorption endpoint: as a large amount of target gas enters the aqueous detection layer 1711, the solution refractive index... When a drift occurs, the angle of the resonance peak shifts laterally, as can be seen in the following figures. Figure 2c , Figure 2c This is a locally magnified curve of the zero-order diffraction angle shift under different refractive indices of the target gas aqueous solution detector layer provided in this application embodiment. Due to the dynamic saturation extrema in gas capture, this application continuously measures and extracts multiple sets of... And calculate the coefficient of variation of the parameter sequence. and real-time zero-order diffraction angle The coefficient of variation error R. The calculation equation is: ,in, For the current measurement period Compared with the previous measurement period The difference. From the first measurement cycle to the current measurement cycle. The average value. When the error When the decay rate drops to less than 5%, it indicates that the solution is fully saturated, and the sampling procedure is automatically stopped. Therefore, in the exemplary embodiment, the above-mentioned multiple sets of real-time zero-order diffraction angles... The criteria for determining whether significant changes have ceased and a steady state has been reached are: Determine the real-time zero-order diffraction angle The coefficient of variation error R is used to determine the real-time zero-order diffraction angle when R does not exceed 5%. Once significant changes cease and a steady state is reached, sampling is complete. The calculation method for the coefficient of variation error satisfies the following relationship: (5) (6) in, For real-time zero-order diffraction angle coefficient of variation, For real-time zero-order diffraction angle The average value of the measurement results This is a single measurement result. To measure the total number of times, This refers to the effective value of the coefficient of variation, which is the value from the first measurement cycle to the current measurement cycle. The average value, i.e. From the first measurement cycle to the current measurement cycle. The average value, For the current measurement period Compared with the previous measurement period The difference.

[0063] The technical solution provided in this application provides a breakthrough by introducing a coefficient of variation error evaluation model based on the zero-order diffraction angle measurement results, which controls the error R to within 5%. It can automatically determine the saturation physical extreme point of dynamic absorption of gas solution, avoiding the detection error of traditional manual setting of fixed sampling time. It is especially suitable for environments where the concentration of formaldehyde in home and medical breath changes rapidly, improving the accuracy of testing and anti-interference ability.

[0064] like Figure 1a As shown, the stepper motor 141 and reduction gear set 142 in the motor module 14 provide rotational power and control the rotational angular velocity. The rotation angle is determined by the data synthesis and processing module 18 based on the calculation result of the error R. That is, by analyzing multiple sets of data... Calculate the coefficient of variation of the parameter sequence. The sampling process is stopped when the error R is less than 5%, and the process stops when rotating.

[0065] S15, Cloud Data Analysis Center determines real-time zero-order diffraction angle With the initial zero-order diffraction angle The zero-order diffraction angle difference is obtained and mapped onto a pre-set second target gas sensitivity distribution model to obtain the real-time refractive index after the aqueous solution absorbs the target gas. .

[0066] This step corresponds to the cloud mapping lookup calculation stage: comparing the stabilized final zero-order diffraction angle with the initial zero-order diffraction angle. Subtract and extract the zero-order diffraction angle difference. .in .

[0067] Introducing sensitivity features , It is the real-time refractive index of the target gas aqueous solution probe layer 1711 after stabilization. With initial refractive index The difference, i.e. . The value to be solved is based on the sensitivity characteristics. Difference between zero-order diffraction angle The solution was obtained. The sensitivity was compared with the preset sensitivity in the cloud. The two-dimensional MAP model library, namely the second target gas sensitivity distribution model mentioned above, includes, for example, Figure 2d The diagram shows the refractive index difference and zero-order diffraction angle difference of the target gas sensitivity, with the refractive index offset coordinates corresponding to the diffraction angle offset coordinates.

[0068] The above sensitivity The initial refractive index of DL is determined through extensive pre-testing at a cloud-based data analysis center, based on the type of target gas to be measured. The experimental method is as follows: Before testing, the initial refractive index of DL... and initial zero-order diffraction angle All are known. A known volume is introduced into DL. After the target gas, the real-time refractive index in DL The zero-order diffraction angle in DL can be accurately measured and verified using numerical methods or refractive index measuring tools. The reflection spectrum can also be obtained by measuring the light wave receiver 162. Therefore, in the known... , , and Under the premise that sensitivity can be calculated And establish sensitivity The MAP database is used for querying.

[0069] The cloud-based data analysis center stores a large amount of data on the sensitivity of target gases under various environmental conditions. A two-dimensional MAP model can be used to adjust the corresponding sensitivity based on the target gas. The data. The precise increase in refractive index at this moment is determined by inverse coordinate mapping. The real-time refractive index of the sample is obtained by adding them together. .like Figure 2d As shown, in terms of sensitivity and Given that the ordinates of the data points and the trend of the curve in the MAP plot are known, the abscissa can be determined by plotting the data points on the curve, thus obtaining the abscissa. Thus, in the known... and Under the premise of, through The real-time refractive index of the sample can be obtained. .

[0070] S16, cloud-based data analysis center or gas concentration measuring device based on real-time refractive index relative initial refractive index The target gas concentration is determined by measuring the refractive index variation and the intake volume measured by the gas path module 15.

[0071] This step corresponds to the stage of obtaining and compensating for the actual environmental concentration: substituting the real-time refractive index obtained in step S15 into the concentration fitting equation. For formaldehyde-acetylacetone solutions, the application coefficient... =4000, =-0.0015, from which the capture concentration in the liquid phase can be determined. For details, please see Figure 2e , Figure 2e This is a MAP empirical fitting diagram of the refractive index of the target gas aqueous solution and the concentration of the target gas provided in the embodiments of this application.

[0072] The above measurements were combined with the total ambient air intake measured by air flow meter 153. Then through Corrected to standard intake volume Then substitute into the equation formula The final precise target gas volume concentration in space is calculated. ,in, The initial concentration of the aqueous solution. The above parameters represent the absorption efficiency of the aqueous solution, and are all known.

[0073] In summary, the technical solution provided in this application uses the aforementioned gas concentration measuring device and connects it to a cloud data analysis center to form a terminal-to-cloud gas concentration measuring system. This system uses the coefficient of variation error of the real-time zero-order diffraction angle to determine the stabilization boundary of gas sampling, and on this basis, extracts the difference of the zero-order diffraction angle and maps it to a preset sensitivity distribution model (MAP). Then, combined with the refractive index shift of a specific aqueous solution, the target concentration is finally calculated using cloud-end collaboration.

[0074] In an exemplary embodiment, the data processing module 18 includes a data storage 181 integrated on a circuit board, a central data processor 182, and a data transmitter and receiver 183; the data processing module 18 is configured to perform the following operations: Responding to the light waves reflected from the aqueous solution, the resonance peaks and their corresponding zero-order diffraction angles in the reflection spectrum are extracted to obtain the reflection spectrum data; When the communication signal reaches the first signal strength, the data transmitter and receiver 183 is driven to send a copy of the reflectance spectral data to the cloud data analysis center to determine the target gas concentration result. If the communication signal does not reach the first signal strength, the first target gas sensitivity distribution model, which is used to characterize the refractive index difference and the zero-order diffraction angle difference, is downloaded from the cloud data analysis center, and the target gas concentration is determined based on the reflection spectral data and the first target gas sensitivity distribution model.

[0075] Accordingly, the above gas concentration measurement method further includes the following steps: When the communication signal does not reach the first signal strength, the gas concentration measuring device downloads the first target gas sensitivity distribution model, which characterizes the refractive index difference and the zero-order diffraction angle difference, from the cloud data analysis center, and determines the first gas concentration result based on the reflection spectrum data and the first target gas sensitivity distribution model. The first target gas sensitivity distribution model is a standard data chart under preset temperature and pressure conditions in a standard environment, and the first gas concentration result is the measurement result determined based on the preset temperature and pressure conditions. When the communication signal reaches a first signal strength, the gas concentration measuring device sends a copy of the reflectance spectral data to the cloud data analysis center to determine the target gas concentration result based on the second target gas sensitivity distribution model. The second target gas sensitivity distribution model includes reference data corresponding to the actual temperature and pressure conditions of the measurement environment, and the target gas concentration result is a measurement result corrected according to the actual temperature and pressure conditions.

[0076] During the pre-deployment preparation phase, if the network quality of the test environment where the gas concentration measuring device is located is poor, belonging to a weak network environment, the gas concentration measuring device can download a MAP (map) of the refractive index difference and zero-order diffraction angle difference of the target gas sensitivity, i.e., the aforementioned first target gas sensitivity distribution model, by searching the online database. However, this MAP is a standard data chart under normal temperature and pressure conditions and does not involve the temperature and pressure correction values ​​in the sample sampling module 17 after sampling stabilization. Therefore, the measurement results of the gas concentration measuring device based on the downloaded local database copy are uncorrected measurement results under normal temperature and pressure conditions. However, for weak network environments, this device can still output a concentration measurement structure for users to refer to; while in strong network environments, online database searching can accurately correct the measurement results based on the temperature and pressure of the stabilized sample sampling module uploaded by the gas concentration measuring device, resulting in a more accurate gas concentration measurement result corrected for actual temperature and pressure conditions.

[0077] Therefore, the technical solution provided in this application embodiment enables the gas concentration measuring device to ensure the continuous effectiveness of analysis and measurement even in extreme environments through weak network communication or by using a local database copy as a backup.

[0078] The above methods can be executed by computer equipment, which refers to electronic devices with data computing and processing capabilities. For example, the steps on the gas concentration measuring device side are executed by the data integration and processing module 18, while the steps on the cloud data analysis center side are executed by a server deployed in the cloud. Typically, computer equipment includes a processor and memory.

[0079] The processor may include one or more processing cores, such as a quad-core processor or an octa-core processor. The processor may be implemented using at least one hardware form of DSP (Digital Signal Processing), FPGA (Field Programmable Gate Array), or PLA (Programmable Logic Array). The processor may also include a main processor and coprocessors. The main processor, also known as the CPU (Central Processing Unit), is used to process data in the wake-up state; the coprocessor is a low-power processor used to process data in the standby state. In some embodiments, the processor may integrate a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content to be displayed on the screen. In some embodiments, the processor may also include an AI (Artificial Intelligence) processor, which handles computational operations related to machine learning.

[0080] The memory may include one or more computer-readable storage media, which may be non-transitory. The memory may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices or flash memory devices. In some embodiments, the non-transitory computer-readable storage media in the memory is used to store at least one instruction, at least one program, code set, or instruction set, which is configured to be executed by one or more processors to implement the gas concentration measurement device and / or the gas concentration measurement method at the cloud data analysis center side.

[0081] In some embodiments, the computer device may also optionally include: a peripheral device interface and at least one peripheral device. The processor, memory, and peripheral device interface can be connected via a bus or signal lines. Each peripheral device can be connected to the peripheral device interface via a bus, signal lines, or a circuit board. The computer device can receive user operation or communication requests to perform the steps in the above method or the operations within those steps.

[0082] Those skilled in the art will understand that the above-listed structures do not constitute a limitation on computer devices and may include more or fewer components than illustrated, or combine certain components, or employ different component arrangements.

[0083] The following are embodiments of the apparatus of this application, which can be used to execute embodiments of the method of this application. For details not disclosed in the apparatus embodiments of this application, please refer to the embodiments of the method of this application.

[0084] This application provides a gas concentration measurement system, which includes a cloud data analysis center and the gas concentration measurement device. The steps performed by the cloud data analysis center and the gas concentration measurement device are the same as those in the above method embodiment, and will not be repeated here.

[0085] It should be noted that the apparatus provided in the above embodiments is only illustrated by the division of the above functional modules when implementing its functions. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the apparatus and method embodiments provided in the above embodiments belong to the same concept, and the specific implementation process can be found in the method embodiments, which will not be repeated here.

[0086] In an exemplary embodiment, a computer-readable storage medium is also provided, the storage medium storing at least one instruction, at least one program, code set, or instruction set, wherein the at least one instruction, the at least one program, the code set, or the instruction set, when executed by a processor, implements the gas concentration measurement device and / or the gas concentration measurement method on the cloud data analysis center side.

[0087] Optionally, the computer-readable storage medium may include: ROM (Read Only Memory), RAM (Random Access Memory), SSD (Solid State Drives), or optical disc, etc. The random access memory may include ReRAM (Resistance Random Access Memory) and DRAM (Dynamic Random Access Memory).

[0088] In an exemplary embodiment, a computer program product or computer program is also provided, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the gas concentration measurement method described above on the gas concentration measuring device and / or the cloud data analysis center side.

[0089] It should be understood that "multiple" as used herein refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. Furthermore, the step numbers described herein are merely illustrative of one possible execution order. In some other embodiments, the steps may not be executed in numerical order, such as two steps with different numbers being executed simultaneously, or two steps with different numbers being executed in the reverse order of the illustration. This application does not limit this.

[0090] In the description of this application, it should be noted that, in the embodiments of this application, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature.

[0091] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, "linking" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. "Fixed connection" refers to a connection where the relative positional relationship remains unchanged after the connection.

[0092] The directional terms used in the embodiments of this application, such as "inner" and "outer," are merely for reference to the directions in the accompanying drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of this application, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application. Furthermore, unless otherwise stated in this application, "multiple" as used in this application refers to two or more.

[0093] In the description of embodiments of this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0094] The above description is merely an exemplary embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A gas concentration measuring device, characterized in that, The gas concentration measuring device includes a main structure (1), and a gas path module (15), an optical path module (16), a sample detection module (17), and a data processing module (18) disposed within the main structure (1). The main structure (1) is provided with a corresponding air inlet (123) and an exhaust outlet (124). The air inlet of the gas path module (15) is fluidly connected to the air inlet (123), the exhaust end of the gas path module (15) is fluidly connected to the air inlet of the sample detection module (17), and the exhaust port of the sample detection module (17) is fluidly connected to the exhaust port (124). The sample detection module (17) has an aqueous solution capable of dissolving the target gas, the refractive properties of the aqueous solution being related to the concentration of the target gas; The optical path module (16) includes a light wave generator (161) and a light wave receiver (162), which are located on opposite sides of the sample detection module (17). The light wave generator (161) is used to emit light waves into the aqueous solution, and the light wave receiver (162) is used to receive the light waves reflected by the aqueous solution and generate reflection spectral data, and transmit the reflection spectral data to the data processing module (18). The data processing module (18) is used to send the reflection spectral data to the cloud data analysis center, and to receive the return data from the cloud data analysis center and output the target gas concentration result based on the return data.

2. The gas concentration measuring device according to claim 1, characterized in that, The sample detection module (17) includes a dielectric grating metal thin film sensor (171) and an interface device (172). The dielectric grating metal thin film sensor (171) includes, along the incident direction of the light wave, an aqueous solution detection layer (1711) for dissolving the target gas, a dielectric grating layer (1712), a metal thin film layer (1713), and a dielectric substrate (1714). The light wave emitted by the optical path module (16) excites surface plasma waves between the target gas aqueous solution detection layer (1711) and the metal thin film layer (1713) to generate resonance peaks in the reflection spectrum.

3. The gas concentration measuring device according to claim 2, characterized in that, The dielectric grating layer (1712) is a silicon grating structure, which includes multiple arrayed grating units. The length of the short side of each grating unit is set to x, the length of the long side is set to y, the distance between the long side and the short side is set to z, and the distance from the midpoint of the arc to the short side is set to k. The structural parameters are set to satisfy the following relationship: （1） （2） （3） （4） in, The period of the grating structure is given. The structure factor is in the range of 0.7 to 0.

8.

4. The gas concentration measuring device according to claim 2, characterized in that, The air path module (15) is provided with an intake turbine (151), an air filter (152) and an air flow meter (153) in sequence along the airflow direction; the aqueous solution detection layer (1711) is filled with the aqueous solution containing pure water and a specific gas absorption reagent. The air containing the target gas enters through the air inlet of the interface device (172) after the air flow meter (153) measures the intake volume. The remaining gas after the target gas dissolves in the aqueous solution is discharged through the exhaust port.

5. The gas concentration measuring device according to claim 2, characterized in that, The light generator (161) operates through continuous small increments. The dielectric grating metal thin film sensor (171) is scanned by varying the incident angle θ, wherein the incident angle θ is in the range of -90°. o Up to 90 o .

6. The gas concentration measuring device according to claim 2, characterized in that, The main structure (1) is also provided with a motor module (14), which is connected to the rotating standard interface (122) at the bottom of the main structure (1). The rotating standard interface (122) is used to connect the fixing device. The motor module (14) is used to drive the main structure (1) to have a predetermined rotational angular velocity relative to the fixing device in the measurement environment. The data processing module (18) is also used to: stop the operation of the motor module (14) when it is detected that the zero-order diffraction angle in multiple consecutive sets of reflection spectral data stops changing or reaches a stable state.

7. The gas concentration measuring device according to claim 1, characterized in that, The data processing module (18) includes a data storage device (181) integrated on a circuit board, a central data processor (182), and a data transmitter and receiver (183); the data processing module (18) is configured as follows: In response to the light wave reflected by the aqueous solution, the resonance peak and its corresponding zero-order diffraction angle in the reflection spectrum are extracted to obtain the reflection spectrum data; When the communication signal reaches a first signal strength, the data transmitter and receiver (183) are driven to send a data copy of the reflection spectrum data to the cloud data analysis center to determine the target gas concentration result; If the communication signal does not reach the first signal strength, a first target gas sensitivity distribution model, which characterizes the refractive index difference and the zero-order diffraction angle difference, is downloaded from the cloud data analysis center, and the target gas concentration is determined based on the reflection spectral data and the first target gas sensitivity distribution model.

8. A method for measuring gas concentration, characterized in that, The gas concentration measurement method is implemented based on a gas concentration measurement system, which includes a cloud data analysis center and a gas concentration measurement device as described in any one of claims 2 to 7. The gas concentration measurement method includes: The cloud-based data analysis center pre-sets the initial refractive index of the aqueous solution. and initial zero-order diffraction angle ; The gas concentration measuring device activates the gas path module (15) to collect gas, so that air carrying the target gas enters the sample detection module (17) and the aqueous solution absorbs the target gas; The gas concentration measuring device controls the optical path module (16) to scan the dielectric grating metal thin film sensor (171) in the sample detection module (17) by changing the incident angle θ, records the resonance peak generated when the reflectivity decreases due to surface plasmon wave coupling, and calculates the corresponding real-time zero-order diffraction angle. The reflection spectral data are obtained. The gas concentration measuring device measures multiple consecutive sets of the real-time zero-order diffraction angles. When significant changes cease and a stable state is reached, the gas collection by the gas circuit module (15) is stopped; The cloud-based data analysis center determines the real-time zero-order diffraction angle. With the initial zero-order diffraction angle The zero-order diffraction angle difference is obtained and mapped onto a preset second target gas sensitivity distribution model to obtain the real-time refractive index of the aqueous solution after absorbing the target gas. ; The cloud data analysis center or the gas concentration measuring device uses the real-time refractive index... relative to the initial refractive index The target gas concentration is determined by the refractive index variation value and the intake volume measured by the gas path module (15).

9. The gas concentration measurement method according to claim 8, characterized in that, The consecutive sets of the real-time zero-order diffraction angles The criteria for determining whether significant changes have ceased and a steady state has been reached are: Determine the real-time zero-order diffraction angle The coefficient of variation error R is used to determine the real-time zero-order diffraction angle when the coefficient of variation error R does not exceed 5%. Once significant changes cease and a steady state is reached, sampling is complete. The calculation method for the coefficient of variation error satisfies the following relationship: （5） （6） in, For real-time zero-order diffraction angle coefficient of variation, For real-time zero-order diffraction angle The average value of the measurement results This is a single measurement result. To measure the total number of times, The effective value of the coefficient of variation refers to the coefficient of variation from the first measurement cycle to the current measurement cycle. The average value, For the current measurement period Compared with the previous measurement period The difference.

10. The gas concentration measurement method according to claim 8, characterized in that, The gas concentration measurement method further includes: When the communication signal does not reach the first signal strength, the gas concentration measuring device downloads a first target gas sensitivity distribution model from the cloud data analysis center, which characterizes the refractive index difference and the zero-order diffraction angle difference of the target gas, and determines a first gas concentration result based on the reflection spectrum data and the first target gas sensitivity distribution model; wherein, the first target gas sensitivity distribution model is a standard data chart under preset temperature and pressure conditions in a standard environment, and the first gas concentration result is a measurement result determined based on the preset temperature and pressure conditions; When the communication signal reaches a first signal strength, the gas concentration measuring device sends a copy of the reflectance spectral data to the cloud data analysis center to determine the target gas concentration result based on the second target gas sensitivity distribution model; wherein, the second target gas sensitivity distribution model includes reference data corresponding to the actual temperature and pressure conditions of the measurement environment, and the target gas concentration result is a measurement result corrected according to the actual temperature and pressure conditions.

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