Method and device for detecting concentration of chlorine ions in air

Abstract

The application relates to the technical field of gas detection, in particular to a method and device for detecting the concentration of chlorine ions in air, which comprises the following steps: obtaining aerosol particles and identifying adsorption tracks, following the particle contact liquid surface behavior, analyzing diffusion paths and residence areas, extracting abnormal diffusion characteristics, screening interference ion tracks, eliminating interference behavior, extending the migration range of chlorine ions, and obtaining the detection result of the concentration of chlorine ions in air. In the application, the adsorption behavior of chlorine ions is identified through the particle attachment path, the residence area is screened in combination with the boundary distribution and residence characteristics in the liquid surface development process, the abnormal area is analyzed according to the direction deviation and track change in the migration path, the interference behavior is eliminated according to the contact relationship of the track in space, the migration track not affected by interference is extended to the range of the gas sample, the tracking of the moving trend of chlorine ions and the identification of the concentration state are completed, the response deviation problem in the conversion process is avoided, and the coherence of the path identification of the particle behavior is enhanced.

Description

Technical Field

[0001] This invention relates to the field of gas detection technology, and in particular to a method and apparatus for detecting chloride ion concentration in air. Background Technology

[0002] The field of gas detection technology involves the collection and quantitative identification of specific components in gas samples. Its core aspects include the control of the gas sampling process, enrichment methods for target components, component identification methods, and concentration calculation methods. Common technical approaches include physical adsorption, liquid absorption, and chemical reaction conversion, supplemented by quantitative analysis methods for concentration conversion. Typically, an air sample is introduced into an absorption liquid or reaction medium to form a sample to be tested, and then the target component is detected using analytical instruments. Among them, the traditional method for detecting chloride ion concentration in air involves converting chloride ions existing in the form of aerosols or particles in the air and dissolving them in pure water to form a water sample containing chloride ions. Then, ion chromatography is used based on the separation order of anions and the conductivity response signal, or silver ion titration is used based on the reaction of chloride ions with silver ions to form silver chloride precipitate and the color endpoint is used to quantitatively analyze the chloride ion content in the water sample.

[0003] Existing technologies use liquid absorption to convert chloride ion particles, relying on water sample reactions to form detection conditions. When aerosol particles are not fully formed or have uneven particle size structure, the diffusion behavior of particles into the reaction medium is easily interrupted or weakened. In the presence of multi-source interference, background ions generated in the liquid medium may also affect the reaction determination process of target ions. Especially in detection scenarios with fluctuating aerosol density or unstable flow velocity, the conversion reaction is prone to time delay and response loss, resulting in the output concentration being out of sync with the actual behavior of aerosols. There is a lack of identification mechanism for the spatial path and continuous behavior of particles, making it difficult to trace the movement trend and distribution of chloride ions in flowing air, thus limiting the scenario adaptability and behavioral controllability of concentration data. Summary of the Invention

[0004] To address the technical problems existing in the prior art, embodiments of the present invention provide a method for detecting chloride ion concentration in air, comprising the following steps:

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a method for detecting chloride ion concentration in air, comprising the following steps:

[0006] S1: Obtain aerosol particles in air samples, track the movement path and continuity characteristics of particle electrode surfaces, analyze the adsorption performance of the attachment process, screen the particle trajectories with chloride ion binding behavior characteristics, and obtain a list of chloride ion attached particle characteristics.

[0007] S2: Based on the list of chloride ion-attached particle characteristics, track the dynamic behavior of particles in contact with the liquid surface, analyze the liquid surface boundary coverage, compare the edge proximity and the overlap of dwelling, filter particle regions, and obtain the distribution structure diagram of the particles dwelling at the interface.

[0008] S3: Based on the distribution structure diagram of particles staying at the interface, track the changes in particle diffusion direction, analyze the reverse extension, stagnation and directional expansion behavior of the path, extract the spatial correlation region, and obtain the abnormal block diagram of the migration path.

[0009] S4: Based on the abnormal block map of the migration path, extract the anion release path in the abnormal area, compare the chloride ion trajectory arrangement, analyze the path overlap and direction consistency behavior, screen interference features, and obtain the interference ion screening and annotation map.

[0010] S5: Based on the interference ion screening and annotation map, extract the undisturbed chloride ion trajectory, eliminate path intersections and time overlaps, extend the migration range to the corresponding flow interval, and obtain the chloride ion concentration detection result in the air.

[0011] As a further aspect of the present invention, the chloride ion attached particle feature list includes spatial path features, motion continuity, attachment state indicators, particle identification markers, and binding behavior characteristics; the interface stationary particle distribution structure diagram includes liquid surface contact distribution, edge proximity features, stationary position map, coverage boundary structure, and continuous contact area; the migration path abnormal block diagram includes diffusion direction changes, reverse behavior trajectories, lingering concentration areas, termination position segments, and spatial correlation segments; the interference ion screening and annotation diagram includes anion release paths, trajectory arrangement patterns, entry time series, directional consistency features, and segment overlap distribution; and the air chloride ion concentration detection results include migration sequences, trajectory screening content, spatial expansion range, and sample flow segments.

[0012] As a further aspect of the present invention, the electrode surface motion path refers to the process of tracking the continuous movement of particles along the electrode region during the extraction of chloride ion behavior changes, analyzing the direction and route of surface sliding, offset and intermittent dwell, and unfolding the position of the path segment in space.

[0013] The dynamics of the liquid surface refer to the spatial changes of particles approaching droplets in the analysis of particle-liquid contact behavior. The sequence of particle-liquid interaction is extracted between the particle's initial contact point, sliding path, and edge distribution position, and the direction of particle movement, duration, and undulation rhythm on the liquid surface are analyzed.

[0014] As a further aspect of the present invention, the boundary coverage state refers to the process of judging the range of the movement path of particles near the edge of the liquid surface in the liquid edge behavior assessment, analyzing the number, direction change and duration of the dwell segment near the edge, and summarizing the distribution state of particles in the boundary region.

[0015] The spatial correlation region refers to the analysis of particle migration path evaluation by comparing the offset starting position, direction fitting degree, and dwelling and aggregation behavior of trajectory segments, and analyzing the behavioral segments of particles overlapping, continuously approaching, and turning and converging in differentiated spatial directions.

[0016] As a further aspect of the present invention, the specific steps of S1 are as follows:

[0017] S101: Acquire aerosol particles in an air sample, track the path extension direction and pause state based on the position changes of the particles during their stay on the surface, identify the movement of the particles during the attachment period, and obtain the attachment behavior trajectory information.

[0018] S102: Based on the adhesion behavior trajectory information, extract the correspondence between the contact area and the path direction of the particles on the electrode surface, analyze the distribution characteristics between the edge trend and the path direction, identify the part where the particle trajectory direction is consistent with the distribution of the region contour, and obtain the range of the fitting feature path.

[0019] S103: Based on the range of the adhesion feature path, filter the particle paths that exhibit chloride ion binding behavior characteristics, select the particles whose path direction remains extended and are distributed in the dwell area, extract the corresponding path trajectory and feature content, and obtain a list of chloride ion attached particle features.

[0020] As a further aspect of the present invention, the specific steps of S2 are as follows:

[0021] S201: Based on the list of chloride ion-attached particle characteristics, track the dynamic behavior of particles in contact with the liquid surface, locate the spatial position of the particle's first contact with the liquid surface, track the movement trajectory on the liquid surface, analyze the trajectory extension direction and surface changes of the boundary area, and obtain the boundary coverage state distribution.

[0022] S202: Based on the boundary coverage state distribution, analyze the positional changes of particles in the liquid surface edge region, calculate the rate of change of the overlapping area between paths, determine the dwell behavior of particles at the edge position and the trajectory contact situation, and obtain the degree of edge contact overlap.

[0023] S203: Based on the degree of edge contact overlap, identify the particle path exhibiting continuous contact area and dwell time on the liquid surface. By analyzing the particle range corresponding to the spatial position and continuous trajectory, divide the associated region and obtain the distribution structure diagram of particles staying at the interface.

[0024] As a further aspect of the present invention, the specific steps of S3 are as follows:

[0025] S301: Based on the distribution structure diagram of particles staying at the interface, a tracking range is set in the liquid surface area to track the change in the path direction of particles during outward diffusion, identify the trajectory segment where the direction changes during the continuous movement of particles, analyze the directional relationship between the path trend and the area boundary, and obtain the trend of diffusion direction change.

[0026] S302: Based on the trend of change in the diffusion direction, identify the trajectory behaviors of reverse extension, stagnation extension and directional expansion in the path, analyze the distribution order of trajectory segments in the path and the connection state between them, calculate the magnitude of change in trajectory direction, locate the distribution area of ​​the behavior trajectory in the diffusion path, and obtain the trajectory behavior feature distribution.

[0027] S303: Based on the trajectory behavior feature distribution, identify the locations of turning points, dense stopping trajectories, and clustered termination segments of the particle's movement path during migration, analyze the relationship between path continuity interruption points and spatial position changes, determine the discontinuous segments of the particle's trajectory, and obtain an abnormal block map of the migration path.

[0028] As a further aspect of the present invention, the specific steps of S4 are as follows:

[0029] S401: Based on the abnormal block map of the migration path, identify the movement trajectory of anions in the abnormal area, extract the starting position and extension direction of the path in the time series, analyze the movement process of the trajectory from the boundary to the interior of the area, determine the diffusion mode of the particles in the spatial range, and obtain the anion release path characteristics.

[0030] S402: Based on the characteristics of the anion release path, compare the trajectory arrangement of chloride ions in the same spatial range, analyze the movement order, direction change and position distribution of the trajectory during the process of entering the region, determine the proximity relationship between the anion trajectory and the chloride ion trajectory in time and space segments, and obtain the path overlap trend characteristics.

[0031] S403: Based on the path overlap trend characteristics, screen anion behaviors that are consistent with chloride ion trajectories in terms of directional continuity and distribution of moving segments, analyze whether the trends, extension ranges and dwell times between paths are related, identify trajectory sequences with overlapping behavioral characteristics, and obtain an interference ion screening and annotation map.

[0032] As a further aspect of the present invention, the specific steps of S5 are as follows:

[0033] S501: Based on the interference ion screening and annotation map, identify the chloride ion trajectory sequence that does not exhibit interference behavior, remove segments in the path that are synchronous with anions in direction and time, analyze the continuous movement state and start and end intervals, and obtain the trajectory sequence range.

[0034] S502: Based on the trajectory sequence range, analyze the path distribution between chloride ion particles, identify the spatial intersection and temporal overlap behavior in the trajectory, determine the spacing relationship between the start and end points and the dwell segment, eliminate path segments with associated features, and filter the trajectory content that moves under different positions and time intervals to obtain the interference-free trajectory interval.

[0035] S503: Based on the interference-free trajectory range, extend the spatial migration behavior of chloride ions, locate the corresponding trajectory coverage area and the volume distribution in the air sample, analyze the frequency and continuity of particle trajectories in the volume range, and obtain the detection results of chloride ion concentration in the air.

[0036] An air chloride ion concentration detection device, comprising:

[0037] The aerosol capture module acquires aerosol particles from an air sample. Under the action of an electric field, the aerosol particles are made to attach to the surface of the capture electrode. The attachment behavior is judged based on the movement trajectory of the particles on the surface. The degree of adhesion between the morphology of the contact area and the direction of residence is analyzed. Trajectory paths that show chloride ion binding characteristics are screened to obtain a list of chloride ion attached particle characteristics.

[0038] The interface adhesion recognition module tracks the adhesion trend of particles to the liquid surface based on the chloride ion adhesion particle feature list, extracts the unfolding contour in the liquid surface area, analyzes the dwelling behavior and the arrangement position of adjacent particles, and filters the area structure that is continuously distributed on the boundary to obtain the interface dwelling particle distribution structure map.

[0039] Based on the distribution structure diagram of particles staying at the interface, the migration path extraction module sets up a liquid surface tracking section, obtains the path changes of particles expanding outward, determines whether there are extension interruptions, directional deviations and stagnation trends in the trajectory, locates the set of abnormal actions within the path, and obtains a migration path abnormal block diagram.

[0040] The interfering ion screening module extracts anion paths within the abnormal area based on the migration path anomaly block map, analyzes the trajectory relationship with chloride ions in the spatial segment, filters behavioral paths that enter the same area in adjacent time periods and show overlapping trajectories, identifies particle trajectories associated with chloride ion behavior interference, and obtains an interfering ion screening annotation map.

[0041] Based on the interference ion screening and annotation map, the concentration output calibration module extracts the chloride ion trajectory sequence that is not affected by interference, eliminates particle behaviors with path intersections and time repetitions, extends the continuous migration path to the gas sample sampling area, analyzes the density of migration distribution, and obtains the chloride ion concentration detection result in the air.

[0042] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0043] In this invention, chloride ion adsorption behavior is identified by particle attachment path, and the residence area is screened by combining the boundary distribution and residence characteristics during the liquid surface unfolding process. Abnormal areas are extracted by analyzing the directional deviation and trajectory change in the migration path. Interfering behaviors are eliminated based on the contact relationship of the trajectory in space. The undisturbed migration trajectory is extended to the gas sample range to complete the tracking of chloride ion movement trend and the identification of concentration state, avoid the response deviation problem in the conversion process, and enhance the coherence of path identification of particle behavior. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention, 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 the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is a schematic diagram of the steps of the present invention;

[0046] Figure 2 This is a detailed schematic diagram of S1 of the present invention;

[0047] Figure 3 This is a detailed schematic diagram of S2 of the present invention;

[0048] Figure 4 This is a detailed schematic diagram of S3 of the present invention;

[0049] Figure 5 This is a detailed schematic diagram of S4 of the present invention;

[0050] Figure 6 This is a detailed schematic diagram of S5 of the present invention;

[0051] Figure 7 This is a schematic diagram of the device module of the present invention. Detailed Implementation

[0052] The technical solution of the present invention will now be described with reference to the accompanying drawings.

[0053] In embodiments of the present invention, words such as "exemplarily," "for example," etc., are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" in the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the word "exemplary" is intended to present the concept in a concrete manner. Furthermore, in embodiments of the present invention, the meaning expressed by "and / or" can be both, or either one.

[0054] In the embodiments of this invention, the terms "image" and "picture" may sometimes be used interchangeably. It should be noted that, without emphasizing the distinction between them, they convey the same meaning. Similarly, the terms "of," "corresponding (relevant)," and "corresponding" may sometimes be used interchangeably. It should be noted that, without emphasizing the distinction between them, they convey the same meaning.

[0055] In this embodiment of the invention, sometimes a subscript such as W1 may be written in a non-subscript form such as W1. When the difference is not emphasized, the meaning they express is the same.

[0056] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0057] Please see Figure 1 This invention provides a method for detecting chloride ion concentration in air, comprising the following steps:

[0058] S1: Obtain aerosol particles from an air sample, and use electrostatic interaction to cause the particles to attach within the collection area. Identify the spatial path and motion continuity of the particles as they remain on the electrode surface. Analyze the adsorption performance based on the similarity between the particle surface morphology and the contact state. Screen the particle trajectories with chloride ion binding behavior characteristics to obtain a list of chloride ion attached particle characteristics.

[0059] S2: Based on the list of chloride ion-attached particle characteristics, track the dynamic behavior of particles in contact with the liquid surface, analyze the boundary coverage state generated by the particles during the unfolding of the liquid surface, compare the proximity and overlap of the particles in the edge region, screen the particle regions with continuous contact area and dwell time characteristics, and obtain the distribution structure diagram of particles at the interface.

[0060] S3: Based on the distribution structure diagram of particles staying at the interface, track the change in the direction of outward diffusion of particles in the tracking area set on the liquid surface, compare the reverse extension, stagnation extension and directional expansion behavior trajectory segments in the path segment, extract the spatial correlation area between the particle concentration and wandering area and the path termination segment, follow the abnormal behavior segments of particles in the migration route, and obtain the migration path abnormal block map.

[0061] S4: Based on the abnormal block map of migration path, extract the release path information of anions in the abnormal area, compare the trajectory arrangement of chloride ions in the same spatial range, analyze the path overlap of differential ions entering the specified area at adjacent time points, screen the anion behavior with consistent trajectory direction and overlapping movement segment, and obtain the interference ion screening and annotation map.

[0062] S5: Based on the interference ion screening and annotation map, extract the chloride ion trajectory sequence that does not show interference behavior, remove the particle behavior content with path intersection and time overlap characteristics, extend the range of chloride ion migration behavior to the flow volume range corresponding to the air sample, and obtain the chloride ion concentration detection result in the air.

[0063] The list of chloride ion-attached particle characteristics includes spatial path characteristics, motion continuity, attachment status indicators, particle identification markers, and binding behavior characteristics. The distribution structure diagram of particles staying at the interface includes liquid surface contact distribution, edge proximity characteristics, dwelling position map, coverage boundary structure, and continuous contact area. The migration path anomaly block diagram includes changes in diffusion direction, reverse behavior trajectory, lingering concentration area, termination position segment, and spatial correlation segment. The interference ion screening and annotation diagram includes anion release path, trajectory arrangement pattern, entry time series, directional consistency characteristics, and segment overlap distribution. The chloride ion concentration detection results in the air include migration sequence, trajectory screening content, spatial expansion range, and sample flow segment.

[0064] Please see Figure 2 The specific steps of S1 are as follows:

[0065] S101: Acquire aerosol particles in an air sample, track the path extension direction and pause state based on the position changes of the particles during their stay on the surface, identify the movement of the particles during the attachment period, and obtain the attachment behavior trajectory information.

[0066] When acquiring aerosol particles from air samples, air containing aerosols is introduced into the sampling chamber at a constant flow rate of 2.5 L / min. The chamber is designed as a closed path, and the electrode surface is arranged parallel to the end of the flow direction. The inertia of the airflow guides the particles to the electrode contact surface. The surface is covered with an image-enhancing material for subsequent image reading and processing. To acquire particle dwell behavior, particle attachment is captured by a continuous image sequence at a frame rate of 30 frames per second. During image processing, the coordinate position of each particle in the continuous frames needs to be extracted. The state is judged based on whether the coordinate position changes between frames. If the particle's position is consistent in 8 out of 10 frames, its state is marked as paused. If the position moves in the same direction in the continuous frames, it is considered as path extension behavior. When tracking the path extension direction, the movement of each particle during the movement needs to be statistically analyzed. The number of movement segments and their corresponding directional angle changes are determined. For example, if a particle extends to the left, up, right, down, and lower right in five consecutive directional segments, its path is considered to be an irregular diffusion pattern. If the direction remains unchanged, it indicates that the particle's movement trend is stable. When judging the movement of a particle during attachment, it is necessary to combine its total movement length with the proportion of the stationary segment. If a particle is stationary for 70% of its entire path, its trajectory can be classified as a low-speed stationary type. Conversely, if more than 80% is in the extension segment, it is classified as a continuous migration type. Finally, based on the trajectory number and particle number, the starting position, path direction, stationary segment distribution, and movement segment changes in space are organized. By filtering the path information, particle trajectories with directional continuity and clear movement period during the attachment process are obtained, thus obtaining the attachment behavior trajectory information.

[0067] S102: Based on the adhesion behavior trajectory information, extract the correspondence between the contact area and the path direction of the particles on the electrode surface, analyze the distribution characteristics between the edge trend and the path direction, identify the part where the particle trajectory direction is consistent with the distribution of the region contour, and obtain the range of the fitting feature path.

[0068] First, the attachment position of the particles in each frame is extracted based on the trajectory coordinates formed by the particles in consecutive image frames. Then, the attachment points are distributed on a two-dimensional coordinate axis to form a path trajectory map. Subsequently, the electrode surface is divided into several planar partitions, each with a boundary of 50×50 pixel image units, used to determine the region to which the particle contact points belong. When extracting the path direction, the difference between the start and end directions of the trajectory line in each segment needs to be calculated, that is, whether the change in the direction range of the line connecting the start and end coordinates is within 45°. If the path direction change of consecutive partitions remains within this angle range, it is determined that the path direction is consistent. Next, the edge contour of the electrode surface needs to be tracked. By extracting the image grayscale boundary or the electrode border setting value, the edge trend curve is drawn, and then the particle trajectory is... The direction and edge trend direction are matched one-to-one. If the angle between the particle path segment and the edge trend curve direction is maintained within 30°, it is considered that the path and edge trend are similar. It is judged that the path segment and the region boundary have a correlation in directional features. When identifying the part where the particle trajectory direction and the region contour distribution are consistent, a segment-to-segment matching operation is performed on all path segment direction sequences and the corresponding region contour direction sequences. For example, if the path segment direction is up, upper right, and right, and the edge contour direction is upper right, right, and lower right, it is considered that a consistent region is formed in the middle segment. Under this condition, the number of matching path segments is counted and corresponding to the spatial distribution. Then, a set of paths that are close to the edge curve when the direction is consistent is selected from multiple continuous path segments, and the range of matching feature paths is obtained.

[0069] S103: Based on the range of the fitting feature path, filter the particle paths that exhibit chloride ion binding behavior, select the particles whose path direction remains extended and are distributed in the dwell area, extract the corresponding path trajectory and feature content, and obtain a list of chloride ion attached particle features.

[0070] First, the paths identified in the previous stage need to be numbered and classified, and the coverage area and directional distribution of each path on the electrode surface need to be defined. Particle paths are grouped according to parameters such as directional change value, number of continuous segments, and number of segments aligned with the boundary direction. During this process, a directional change judgment interval should be set. For example, when judging directional continuity, if the directional deviation angle of a particle in three consecutive image frames is less than 15 degrees, it can be considered as maintaining an extended directional state. For such paths, it is necessary to further determine whether they are distributed in areas with dwelling characteristics. The method for determining dwelling areas is to count the number of times a particle appears at a certain position in each path. When the number of times a particle appears at that position in the image frames is greater than 70% of the total number of frames, that position is considered a dwelling area. The particle is considered to be a stopping point. Further screening is conducted to identify particle trajectories whose path extension direction intersects with the stopping area. If the particle path has directional continuity characteristics in consecutive frames and the end of the path overlaps within the stopping area, then the path is considered to be related to the binding behavior characteristics. Such paths are compared by matching behavior performance indicators. After filtering out path segments that do not meet the conditions, the spatial orientation data, motion direction labels, corresponding particle numbers, path length, and number of continuous frames in the remaining paths are extracted. Combined with the data items of the previously attached boundary, the trajectory sequence, area coverage, direction parameters, and movement stability indicators are extracted sequentially for the selected paths to describe the attachment performance of each trajectory, resulting in a list of chloride ion attached particle features.

[0071] Please see Figure 3 The specific steps of S2 are as follows:

[0072] S201: Based on the list of chloride ion-attached particle characteristics, track the dynamic behavior of particles in contact with the liquid surface, locate the spatial position of the particle's first contact with the liquid surface, track the movement trajectory on the liquid surface, analyze the trajectory extension direction and surface changes of the boundary region, and obtain the boundary coverage state distribution.

[0073] First, extract particle ID, trajectory start frame, direction change sequence, and stationary point coordinates from the feature list. Combine this with the image sequence to track the corresponding particles sequentially. In the initial contact phase with the liquid surface, identify the point where the particle trajectory first coincides with the liquid surface boundary as the initial contact point. Identify the coordinates of the particle's first contact with the liquid surface by methods such as grayscale changes and contrast boundary pixel changes. During this process, a grayscale contrast threshold of 45 can be set; if the grayscale difference between the pixels around the particle's edge exceeds this value, it is considered boundary contact. After locating the spatial position of the particle's first contact with the liquid surface, track the particle's positional changes in consecutive image frames, identifying the displacement direction between each frame in the trajectory. For example, if the particle moves sequentially along the positive x-axis from frame 1 to frame 6, with a total displacement of 60 pixels, it can be determined that the particle exhibits a consistent, extended trajectory at this stage. Subsequently, further steps are needed... The path lines of all particle trajectories in the liquid surface area are superimposed, and the areas covered by particle trajectories are identified by color layering or numbering. The liquid surface area is divided into 5×5 grid units to count the number of times each region is traversed by particle trajectories. During the statistical process, a single region covered by more than three particle trajectories can be defined as an active boundary region. The relative relationship between this region and the liquid surface boundary is then analyzed to determine whether the active regions are concentrated at the edge or middle of the droplet. By comparing the distribution trend of these regions with the direction of particle movement point by point, for example, if particles generally exhibit inward movement trajectories in the edge region, it is determined that there is coverage behavior at the boundary of that region. Finally, based on the activity frequency, movement direction, and trajectory density characteristics of different particle paths near the liquid surface boundary, the response relationship between each region and particle behavior is determined, and the boundary coverage state distribution is obtained.

[0074] S202: Based on the boundary coverage state distribution, analyze the positional changes of particles in the liquid surface edge region, calculate the rate of change of the overlapping area between paths, determine the dwell behavior of particles at the edge position and the trajectory contact situation, and obtain the degree of edge contact overlap.

[0075] The specific formula for calculating the rate of change of the overlapping area between paths is as follows;

[0076] ;

[0077] in, This represents the rate of change of the overlap area between particle paths at time t, with the dimension of area divided by time. This represents the total change in the overlap area of ​​particle i during the observation period. The total duration of particle i's participation in the overlapping motion is measured in units of time. This represents the horizontal drift length of particle i during that time period. This represents the vertical drift length of particle i during that time period. Represents the number of sample particles;

[0078] Particle 1: , , , ;

[0079] Particle 2: , , , ;

[0080] Particle 3: , , , ;

[0081] The calculation yields:

[0082] Particle 1 item: ;

[0083] Root denominator: ;

[0084] The individual results are: ;

[0085] Particle 2 terms: √ denominator The single result is ;

[0086] Particle 3 terms: √ denominator The single result is ;

[0087] Calculate the average:

[0088] ;

[0089] Interpretation of results and numerical significance: The path overlap rate caused by particle behavior during the current detection period is 0.01081 m² / s, which is lower than the set interference judgment benchmark value of 0.015 m² / s, indicating that the particle behavior is stable and no large-area boundary interference has been formed.

[0090] Explanation of the innovative aspects of the formula:

[0091] The advantage of the formula is that by coupling the rate of area change with the path amplitude, a multi-dimensional control mechanism for the intensity of particle behavior changes is constructed, making boundary state recognition more responsive and representative of behavior.

[0092] S203: Based on the degree of edge contact overlap, identify the particle path that exhibits continuous contact area and residence time on the liquid surface. By analyzing the particle range corresponding to the spatial position and continuous trajectory, divide the associated region and obtain the distribution structure diagram of particles staying at the interface.

[0093] First, the contact behavior parameters are extracted in segments. The spatial coordinates of the particles in the image sequence are read, and particles that stay in the same area within consecutive frames are marked as dwelling behavior. The number of consecutive frames is counted. If the coordinates do not change significantly for more than 30 frames within 50 frames, the path segment is considered to have continuous dwelling behavior. When processing the contact area, the trajectory width of each particle within the liquid surface area is spatially mapped. By superimposing the trajectory coverage of each frame in a 10×10 pixel grid, a contact area distribution map of the particle on the liquid surface is formed. Then, particles with continuous overlapping areas in their trajectories are compared to confirm whether they have spatial continuity. If the trajectories of two or more particles appear consecutively in adjacent frames in the same area, and the spatial distance between the trajectories is less than 5 pixels and the time interval does not exceed 10 frames, they can be judged as the same segment. The relevant paths are then merged based on the overlap of position and time sequence, extracting path groups formed by particle aggregation in continuous contact areas. Different particle coverage areas are further divided according to regional density, and each path group is numbered. By recording the start and end positions, directional extension trends, and dwell stage divisions of each path on the liquid surface, it is determined whether the path belongs to the same particle group's influence area. For example, if the paths of particles A, B, and C overlap in the range of x=80 to x=110 and are all in the middle dwell stage of the path, then this segment is marked as an associated block. Finally, all particle paths with continuous contact area, identifiable dwell stages, and spatial intersections are summarized as distribution area boundaries, dividing the contact area groups based on particle movement and dwell behavior, and obtaining the interface dwell particle distribution structure diagram.

[0094] Please see Figure 4 The specific steps of S3 are as follows:

[0095] S301: Based on the distribution structure diagram of particles staying at the interface, a tracking range is set in the liquid surface area to track the change of path direction of particles during outward diffusion, identify the trajectory segment of the particle changing direction during continuous movement, analyze the directional relationship between the path trend and the area boundary, and obtain the trend of diffusion direction change.

[0096] First, the boundary area with high particle density is read from the image as the initial range. This range, based on the static image coordinates, can be set as an area of ​​60 to 120 pixels on the x-axis and 80 to 140 pixels on the y-axis for subsequent trajectory tracking. Within this tracking area, the first frame contact point of each particle is selected and its trajectory path is recorded. The coordinate points corresponding to the particle movement trajectory are extracted according to the image frame sequence. Then, the path direction of the particle in each frame is obtained through the coordinate sequence. The particle movement direction can be represented by the displacement vector of the current frame and the previous frame, forming a set of path segment directions between frames. When the path segment direction remains unidirectional or approximately extended within 3 consecutive frames, it is judged as a continuous direction segment. When the particle direction changes from left to right to the upper right or upper direction, it indicates that the trajectory direction has changed. To identify such path segments with direction changes, it is necessary to count the time periods in each particle's trajectory where the direction angle changes by more than 30 degrees as direction change points. Further tracking of the displacement segments before and after the turning point is conducted to determine whether there are repeated changes or irregular back-and-forth behaviors. When analyzing the directional relationship between the path trend and the region boundary, the angle between the particle direction vector and the boundary direction should be used as the basis for judgment. The boundary direction can be determined by the edge direction line segment extracted from the image edge. If the angle between the particle trajectory direction and the boundary direction is less than 20 degrees, it can be considered that the path is close to the boundary trend. If the angle is greater than 60 degrees, it means that the trajectory direction deviates far from the region edge direction. In this process, the direction is statistically analyzed every 10 frames in the path, and the relative angle relationship between each directional segment and the boundary position is determined. Through the statistical relationship between the trajectory direction of all particles and the boundary, the directional change trend of particle diffusion path in different regions within the entire liquid surface range is identified. Finally, the diffusion direction change trend is obtained based on the particle path change characteristics, turning distribution position and boundary direction consistency.

[0097] S302: Based on the trend of diffusion direction change, identify the trajectory behavior of reverse extension, stagnation extension and directional expansion in the path, analyze the distribution order of trajectory segments in the path and the connection state between them, calculate the amplitude of trajectory direction change, locate the distribution area of ​​the behavior trajectory in the diffusion path, and obtain the trajectory behavior feature distribution.

[0098] The specific formula for calculating the magnitude of the change in trajectory direction is as follows:

[0099] ;

[0100] in, Representing the The magnitude of change in the direction of the segment trajectory Representing the The horizontal component displacement of the segment trajectory. Representing the The vertical component displacement of the segment trajectory. Representing the The velocity of the segment particle, Representing the The spatial reaction delay corresponding to the trajectory segment represents the first segment. The path length of the segment trajectory;

[0101] The value is obtained by the difference in x-coordinate between the particle's initial and final positions on the trajectory. For example, if the initial position is 1.2m and the final position is 2.4m, then... ;

[0102] If the starting and ending y-coordinates are 0.8m and 1.3m respectively, then... ;

[0103] The value is obtained by sampling the ratio of particle displacement to sampling time at high frequency. If a particle completes a path of 1.3m within 0.15s, then... ;

[0104] The maximum inter-frame delay measured in the image sequence is 0.08s, then... ;

[0105] : Calculated using the Pythagorean theorem, that is:

[0106] ;

[0107] Substitute the above into the calculation formula:

[0108] , , , , ;

[0109] After substituting, we get:

[0110] ;

[0111] ;

[0112] ;

[0113] ;

[0114] Interpretation of Results and Numerical Significance: The first The trajectory direction change amplitude is 0.5335, based on the preset judgment interval in the stable diffusion path of chloride ions. The result falls in the middle area, indicating that there is a moderate degree of directional change in the current trajectory segment;

[0115] Explanation of the innovative aspects of the formula:

[0116] The advantage of the formula is that it reflects the spatial direction evolution of the trajectory segment through the direction cosine term and introduces the time response through the particle response displacement ratio term, so as to quantitatively describe the linkage between the sudden change in the direction of the diffusion trajectory and the particle reaction behavior, thereby revealing the dynamic correlation between particle behavior and path change.

[0117] S303: Based on the distribution of trajectory behavior characteristics, identify the locations of turning points, dense stopping trajectories, and clustering of termination segments in the movement path of particles during migration, analyze the relationship between the interruption points of path continuity and changes in spatial position, determine the segments of discontinuous path connection in the particle trajectory, and obtain an abnormal block map of the migration path.

[0118] First, the spatial coordinate sequence of each particle trajectory is extracted in chronological order. Based on this, the changes in the continuous direction of each trajectory segment are statistically analyzed. A turning point is marked when the direction change is greater than 45 degrees and occurs more than twice consecutively. For sections where consecutive frame positions almost overlap, a dwell time determination is performed. If a particle dwells in a small area for more than 30 frames and multiple trajectories overlap within that area, the area is considered a densely dwelling area. Simultaneously, the final path segment before the trajectory terminates is recorded. The overlapping termination points of multiple particle trajectories within the same time period are identified within the area surrounding the trajectory termination point. When the trajectory ends are concentrated in an area with a radius of no more than 10 pixels, and more than three particles terminate in this area, the location is defined as a termination aggregation point. During this process, the coordinates of the position points corresponding to various trajectory features and the occurrence times must be recorded simultaneously. Image frame numbers are used, and the path behavior characteristics are organized according to particle numbers. When further analyzing the relationship between path continuity interruption points and spatial position changes, the positions of time frame breaks in the trajectory are screened. If there are more than 10 frames of unrecorded behavior or a spatial jump distance of more than 20 pixels between two consecutive segments, it is considered a path interruption. By observing the position difference before and after the break point and the change in trajectory direction, it can be determined whether there is a discontinuity in the path connection segment. If the direction shift of the trajectory segment before and after is obvious and there is no smooth transition, it indicates that the path connection is discontinuous. Such trajectories are included in the scope of abnormal path segments. Finally, all the parts of the particle path that have abrupt changes in direction, overlapping dwell heights, clustered termination points, or discontinuous connection imbalances are presented in the form of coordinate distribution. The distribution of areas where abnormal behavior frequently occurs within the spatial position range is extracted to obtain the migration path abnormal block map.

[0119] Please see Figure 5 The specific steps of S4 are as follows:

[0120] S401: Based on the migration path anomaly block map, identify the movement trajectory of anions in the abnormal area, extract the starting position and extension direction of the path in the time series, analyze the movement process of the trajectory from the boundary to the interior of the region, determine the diffusion mode of the particles in the spatial range, and obtain the anion release path characteristics.

[0121] First, regions marked as abnormal blocks are filtered in the image, and their corresponding coordinate ranges are determined. These coordinate regions are used as search boundaries. The anion particle numbers and their complete trajectory data within each region are retrieved sequentially. The position information of each particle is arranged according to the time series. The entry direction of the trajectory is determined by extracting the starting point position frame by frame, and the extension direction is determined based on the changing pattern of the path direction in the time series. For example, if a particle starts at x=40, y=60 and moves continuously in the positive x-axis direction in subsequent frames, its path extension direction is horizontal to the right. After extracting the path, its displacement trajectory between the boundary line of the abnormal block and the internal region is segmented. The path trajectory of the particle from the edge to the interior is analyzed to see if there are characteristic behaviors such as turning back, detouring, or short-distance stops. If the particle path shows two or more directional reversals within the region, or if there are obvious discontinuous extension segments, further analysis is performed. If the particle's movement is classified as non-uniform diffusion, the diffusion pattern within the spatial range is determined by the ratio between the distance from the starting point to the ending point of the trajectory and the total path length. If the ratio is less than 0.5, it indicates that the particle has made multiple round trips within the abnormal area, and the diffusion behavior is biased towards stagnation. If the ratio is above 0.8, it can be considered as a one-time directional diffusion. Combining multiple parameters such as the frequency of intersection between the particle's behavior path and the regional boundary, the proportion of frames in the dwell segment, and the number of directional turns, the behavior of the particle is comprehensively classified. Trajectories with concentrated spatial offset and repeated entry and exit from abnormal blocks are summarized to form the trend of this type of anion's movement within the spatial range. Finally, based on the classification of the behavioral characteristics and directional consistency of multiple particle paths, the spatial position aggregation of the extension patterns, dwell structures, and intersection positions between paths is performed to obtain the anion release path characteristics.

[0122] S402: Based on the characteristics of anion release pathways, compare the trajectory arrangement of chloride ions in the same spatial range, analyze the movement order, direction changes and position distribution of the trajectories during the process of entering the region, determine the proximity relationship between anion trajectories and chloride ion trajectories in time and space segments, and obtain the path overlap trend characteristics.

[0123] First, the labeled anion path range is identified. Chloride ion trajectory data is extracted within the corresponding space and organized into a trajectory sequence by particle number. Then, the starting position, direction of movement, and time period of entry into the region of the anion trajectories are compared to obtain the differences in the path structure between the two ion groups. To determine the entry order of particle trajectories, the particle number must be associated with its corresponding image frame sequence. When anions and chloride ions appear in consecutive frames within the same region, their relative order of entry can be determined. For example, if anions enter at frame 15 and chloride ions appear at frame 13, chloride ions are considered to have entered first. When analyzing changes in path direction, each trajectory direction sequence needs to be extracted, and the turning point positions and angle distribution of consecutive direction segments in the trajectory are statistically analyzed. If the first five segments of the two particle path direction sequences are consistent, they are considered to have similar directions of movement. Observe the overlapping area of ​​the path projection in the image space to identify the degree of overlap between the chloride ion path and the anion path in the x and y coordinates. If the number of trajectory segments in the overlapping area exceeds three and the total length exceeds 40% of the total path length, it is judged that the paths are close in space. In addition, the locations where collinear behavior occurs in the trajectory should also be counted. For example, if the chloride ion path extends to the upper right and the anion path extends in the same trend in the same coordinate slope direction, it indicates that the two paths have a corresponding relationship. Finally, it is necessary to compare whether the time distribution of the behavioral characteristics of the two types of ions before and after entering the abnormal area is synchronized. For example, whether they stay in the same area continuously between the 20th and 35th frames. If both have continuous path segments and similar trajectory shapes in both time and space, it is judged that the two types of ions have a trajectory overlap trend, and the path overlap trend characteristics are obtained.

[0124] S403: Based on the path overlap trend characteristics, screen anion behaviors that are consistent with chloride ion trajectories in terms of directional continuity and distribution of moving segments, analyze whether there is a correlation between the trend, extension range and residence time of the paths, identify trajectory sequences with overlapping behavioral characteristics, and obtain an interference ion screening and annotation map.

[0125] First, the identified directional feature parameters in the path overlap trend are categorized. Path segments with the same or similar directions in the same area for anion and chloride ion trajectories are numbered and labeled. Continuous directional segments are extracted according to time sequence, and their duration of at least 20 frames is used as a criterion for directional consistency. Subsequently, chloride ion movement path segments are extracted within the same spatial range, and the coverage area from the trajectory start point to the end point is marked. Spatial matching is performed on anion trajectory segments. If the start and end points of an anion path segment are in the same spatial grid as the chloride path segment, and the direction labels are consistent, the segment is classified as a trajectory shape matching segment. When analyzing whether there is a correlation between path trend, extension range, and dwell time, the continuity of coordinate points within the path segment is evaluated to identify whether there is extension under the same direction. The trajectory is analyzed, and the number of frames spent in the trajectory is counted. For example, if chloride ions stay in the same trajectory segment for 45 frames, and anions stay for 43 frames in the same path segment, the difference is within 2 frames. This indicates that the two types of trajectories are consistent in terms of dwell time. If the movement direction and duration meet the above conditions, and the trajectory lengths differ by no more than 10 pixels, it indicates that the paths are related. These anion trajectories are marked as overlapping paths with behavioral characteristics. They are further grouped according to the degree of trajectory similarity through clustering to form a set of anion interference trajectories with chloride ion paths as a reference. The particle number, path segment sequence, direction classification, and spatial overlap label are output and summarized into the range of anion characteristics that can determine interference behavior. Finally, the screening process of interference particle trajectories is completed, and the interference ion screening and annotation map is obtained.

[0126] Please see Figure 6 The specific steps of S5 are as follows:

[0127] S501: Based on the interference ion screening and annotation map, identify the chloride ion trajectory sequence that does not show interference behavior, remove the segments in the path that are synchronous with the anions in direction and time, analyze the continuous movement state and start and end intervals, and obtain the trajectory sequence range.

[0128] First, chloride ion trajectory segments with the same direction number as the already identified anion direction segments are filtered out from the image. Then, chloride ion path segments within the same frame time range as the anion trajectories are further investigated and removed from the target trajectory sequence. Next, the continuous movement state and the interval between the start and end points of each remaining trajectory segment are evaluated. A continuous trajectory is defined as a path sequence where the coordinate offset between adjacent frames does not exceed 15 pixels and the interval between frame numbers does not exceed 2 frames. Trajectory segments that do not meet this standard are eliminated. Further, the distance range between each start and end point in the trajectory sequence is determined. Based on whether the spatial span exceeds the offset limit set (±20 pixels) for the average particle path length (e.g., the average movement length of chloride ion particles is 95 pixels), the trajectory is further evaluated. The positional rationality of the movement state between the endpoints is judged. If the distance between the start and end points of a continuous trajectory segment exceeds the offset limit, it indicates that the movement of that segment is discontinuous and is not included in the target range. Otherwise, it is included in the valid trajectory sequence. For example, a particle is detected in the figure as trajectory segment 1 with the starting frame F12 and the ending frame F35, a total of 24 frames, a path length of 88 pixels, and a direction label of 3. This is inconsistent with any direction label in the anion trajectory segment, and the particle does not have any time frame overlap in the figure. Therefore, this trajectory segment can be identified as an undisturbed path. Finally, through the above multiple screening actions, all chloride ion path segments that meet the conditions are aggregated, and their overall spatial direction, movement duration, and extension characteristics are determined to obtain the trajectory sequence range.

[0129] S502: Based on the trajectory sequence range, analyze the path distribution between chloride ion particles, identify the spatial intersection and temporal overlap behavior in the trajectory, determine the spacing relationship between the start and end points and the dwell segment, eliminate path segments with associated features, and filter the trajectory content that moves under different positions and time intervals to obtain the interference-free trajectory interval.

[0130] First, the coordinates of each particle's trajectory at any given time point are compared with the coordinates of other particles at the same time point to determine if there are two or more particles whose movement paths intersect within the same frame. If the distance between the intersection points is less than 20 pixels, the intersection path segment is marked as an intersection behavior. Then, the spatial distance between the dwell segment of each particle and the start and end points of other particle paths is checked frame by frame. The initial criterion for positional overlap is that the straight-line distance between the center points of the start and end segments is less than 30 pixels. Trajectory segments that meet this condition are drawn separately. Then, the frame number segment corresponding to the dwell segment is checked to see if it coincides with another path. If the frame numbers overlap for more than 5 frames, it is considered that there is temporal overlap behavior. The path segment is marked as an interference segment and removed from the target trajectory sequence. For the remaining path part, the coordinate jump pattern between the start and end points of each trajectory is measured, and the time interval between adjacent frames is calculated. The process involves grading and evaluating the proportion of time a particle appears stationary within a path segment. If the cumulative length of a pause segment in any path exceeds 10 frames, it is necessary to further determine whether the pause segment overlaps with the movement segments of other particles. If they overlap, they are removed as suspected related trajectories. Finally, for the remaining path segments, the path positions of different trajectories are compared according to their coordinate range in the spatial plane. Any two trajectories with a horizontal and vertical coordinate offset exceeding 50 pixels are judged as having differentiated positional performance. At the same time, two paths with an inter-frame interval of not less than 15 frames on the time axis are judged as performance segments with reasonable time intervals. For example, if a particle path number is P34, its starting frame is F20, its ending frame is F85, the average inter-frame coordinate change is about 12 pixels, the pause segment length does not exceed 8 frames, and the entire segment does not have spatial overlap or temporal coincidence with other particle trajectories, an interference-free trajectory interval is obtained.

[0131] S503: Based on the interference-free trajectory range, extend the spatial migration behavior of chloride ions, locate the corresponding trajectory coverage area and the volume distribution in the air sample, analyze the frequency and continuity of particle trajectories in the volume range, and obtain the detection results of chloride ion concentration in the air.

[0132] First, based on the coverage coordinate sequence of each trajectory, the corresponding 3D grid number is matched point by point. After establishing a grid correspondence table, the number of chloride ion trajectory segments falling into the region is counted for each numbered unit. At the same time, the number of times particles appear in the same grid is accumulated to construct a frequency table. Then, the number of frames for each grid number is distinguished, and trajectory segments with more than 10 frames in a continuous frame range are selected as path representations with stable migration characteristics in that grid. Furthermore, volume partitioning statistics are performed based on the numbered blocks to delineate the spatial range corresponding to each number. For example, if a number is G25, its corresponding spatial boundary range is a cubic space with x-axis 30 to 50, y-axis 40 to 60, and z-axis 10 to 30. If a total of 5 chloride ion trajectories fall into this numbered block, and each trajectory falls into this grid... If the number of frames spent in the region is 12, 14, 16, 18, and 19 respectively, then this region is considered a high-frequency segment for further statistical processing. Based on the ratio of the number of particles in each grid to the number of trajectory frames, the average residence time of particles in different volume regions can be obtained. By defining the proportion of space volume occupied by different particle frequencies, the change in trajectory frequency density in each volume interval is calculated. If the frequency of particles in a region with a volume of 8×10³ units exceeds 40 times and the time interval is less than 8 frames, the region can be judged as a high-concentration distribution area. After completing the frequency accumulation of all grids, the correspondence between trajectory frequency and space volume is formed, and finally the frequency value sequence of particles in the space volume grid is output. Based on this, different frequency intervals are divided into three levels: low, medium, and high, to obtain the detection results of chloride ion concentration in the air.

[0133] Please see Figure 7 An air chloride ion concentration detection device, comprising:

[0134] The aerosol capture module acquires aerosol particles from an air sample. Under the action of an electric field, the aerosol particles are made to attach to the surface of the capture electrode. The attachment behavior is judged based on the movement trajectory of the particles on the surface. The degree of adhesion between the morphology of the contact area and the direction of residence is analyzed. Trajectory paths that show chloride ion binding characteristics are screened to obtain a list of chloride ion attached particle characteristics.

[0135] The interface adhesion recognition module is based on a list of chloride ion-attached particle features. It tracks the adhesion trend of particles to the liquid surface, extracts the unfolding contour in the liquid surface area, analyzes the dwelling behavior and the arrangement position of adjacent particles, and filters the regional structure that is continuously distributed on the boundary to obtain the distribution structure map of interface dwelling particles.

[0136] The migration path extraction module is based on the distribution structure diagram of particles staying on the interface. It sets up liquid surface tracking sections, obtains the path changes of particles expanding outward, judges whether there are extension interruptions, directional deviations and stagnation trends in the trajectory, locates the set of abnormal actions in the path, and obtains the migration path abnormal block map.

[0137] The interfering ion screening module extracts anion paths within abnormal regions based on the migration path anomaly block map, analyzes the trajectory relationship with chloride ions in spatial segments, filters behavioral paths that enter the same region in adjacent time periods and exhibit overlapping trajectories, identifies particle trajectories associated with chloride ion behavior interference, and obtains an interfering ion screening annotation map.

[0138] The concentration output calibration module extracts the unaffected chloride ion trajectory sequence based on the interference ion screening and annotation map, eliminates particle behaviors with path intersections and time repetitions, extends the continuous migration path to the gas sample sampling area, analyzes the density of migration distribution, and obtains the chloride ion concentration detection result in the air.

[0139] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for detecting chloride ion concentration in air, characterized in that, Includes the following steps: S1: Obtain aerosol particles in air samples, track the movement path and continuity characteristics of particles on the electrode surface, analyze the adsorption performance of the attachment process, screen the particle trajectories with chloride ion binding behavior characteristics, and obtain a list of chloride ion attached particle characteristics. S2: Based on the list of chloride ion-attached particle characteristics, track the dynamic behavior of particles in contact with the liquid surface, analyze the liquid surface boundary coverage, compare the edge proximity and the overlap of dwelling, filter particle regions, and obtain the distribution structure diagram of the particles dwelling at the interface. S3: Based on the distribution structure diagram of particles staying at the interface, track the changes in particle diffusion direction, analyze the reverse extension, stagnation and directional expansion behavior of the path, extract the spatial correlation region, and obtain the abnormal block diagram of the migration path. S4: Based on the abnormal block map of the migration path, extract the anion release path in the abnormal area, compare the chloride ion trajectory arrangement, analyze the path overlap and direction consistency behavior, screen interference features, and obtain the interference ion screening and annotation map. S5: Based on the interference ion screening and annotation map, extract the undisturbed chloride ion trajectory, eliminate path intersections and time overlaps, extend the migration range to the corresponding flow interval, and obtain the chloride ion concentration detection result in the air. The electrode surface motion path refers to the process of tracking the continuous movement of particles along the electrode region during the extraction of chloride ion behavior changes, analyzing the direction and route of surface sliding, offset and intermittent residence, and unfolding the position of the path segment in space. The dynamics of the liquid surface refer to the spatial changes of particles approaching droplets in the analysis of particle-liquid contact behavior. The sequence of particle-liquid interaction is extracted between the particle's first contact point, sliding path, and edge distribution position. The movement direction, duration, and undulation rhythm of particles on the liquid surface are analyzed. The boundary coverage state refers to the process of judging the range of particle movement paths near the edge of the liquid surface in the liquid edge behavior assessment, analyzing the number, direction changes and duration of the segments that stay near the edge, and summarizing the distribution state of particles in the boundary region. The spatial correlation region refers to the analysis of particle migration path evaluation by comparing the offset starting position, direction fitting degree, and dwelling and aggregation behavior of trajectory segments, and analyzing the behavioral segments of particles overlapping, continuously approaching, and turning and converging in differentiated spatial directions.

2. The method for detecting chloride ion concentration in air according to claim 1, characterized in that, The list of chloride ion-attached particle characteristics includes spatial path characteristics, motion continuity, attachment state indicators, particle identification markers, and combined behavioral characteristics. The distribution structure diagram of particles staying at the interface includes liquid surface contact distribution, edge proximity characteristics, dwelling position map, coverage boundary structure, and continuous contact area. The abnormal block diagram of migration path includes changes in diffusion direction, reverse behavior trajectory, lingering concentration area, termination position segment, and spatial correlation segment. The interference ion screening and annotation diagram includes anion release path, trajectory arrangement pattern, entry time series, directional consistency characteristics, and segment overlap distribution. The detection results of chloride ion concentration in the air include migration sequence, trajectory screening content, spatial expansion range, and sample flow segment.

3. The method for detecting chloride ion concentration in air according to claim 1, characterized in that, The specific steps of S1 are as follows: S101: Acquire aerosol particles in an air sample, track the path extension direction and pause state based on the position changes of the particles during their stay on the electrode surface, identify the movement of the particles during the attachment period, and obtain the attachment behavior trajectory information. S102: Based on the adhesion behavior trajectory information, extract the correspondence between the contact area and the path direction of the particles on the electrode surface, analyze the distribution characteristics between the edge trend and the path direction, identify the part where the particle trajectory direction is consistent with the distribution of the region contour, and obtain the range of the fitting feature path. S103: Based on the range of the adhesion feature path, filter the particle paths that exhibit chloride ion binding behavior characteristics, select the particles whose path direction remains extended and are distributed in the dwell area, extract the corresponding path trajectory and feature content, and obtain a list of chloride ion attached particle features.

4. The method for detecting chloride ion concentration in air according to claim 1, characterized in that, The specific steps of S2 are as follows: S201: Based on the list of chloride ion-attached particle characteristics, track the dynamic behavior of particles in contact with the liquid surface, locate the spatial position of the particle's first contact with the liquid surface, track the movement trajectory on the liquid surface, analyze the trajectory extension direction and surface changes of the boundary area, and obtain the boundary coverage state distribution. S202: Based on the boundary coverage state distribution, analyze the positional changes of particles in the liquid surface edge region, calculate the rate of change of the overlapping area between paths, determine the dwell behavior of particles at the edge position and the trajectory contact situation, and obtain the degree of edge contact overlap. S203: Based on the degree of edge contact overlap, identify the particle path exhibiting continuous contact area and dwell time on the liquid surface. By analyzing the particle range corresponding to the spatial position and continuous trajectory, divide the associated region and obtain the distribution structure diagram of particles staying at the interface.

5. The method for detecting chloride ion concentration in air according to claim 1, characterized in that, The specific steps for S3 are as follows: S301: Based on the distribution structure diagram of particles staying at the interface, a tracking range is set in the liquid surface area to track the change in the path direction of particles during outward diffusion, identify the trajectory segment where the direction changes during the continuous movement of particles, analyze the directional relationship between the path trend and the area boundary, and obtain the trend of diffusion direction change. S302: Based on the trend of change in the diffusion direction, identify the trajectory behaviors of reverse extension, stagnation extension and directional expansion in the path, analyze the distribution order of trajectory segments in the path and the connection state between them, calculate the magnitude of change in trajectory direction, locate the distribution area of ​​the behavior trajectory in the diffusion path, and obtain the trajectory behavior feature distribution. S303: Based on the trajectory behavior feature distribution, identify the locations of turning points, dense stopping trajectories, and clustered termination segments of the particle's movement path during migration, analyze the relationship between path continuity interruption points and spatial position changes, determine the discontinuous segments of the particle's trajectory, and obtain an abnormal block map of the migration path.

6. The method for detecting chloride ion concentration in air according to claim 1, characterized in that, The specific steps of S4 are as follows: S401: Based on the abnormal block map of the migration path, identify the movement trajectory of anions in the abnormal area, extract the starting position and extension direction of the path in the time series, analyze the movement process of the trajectory from the boundary to the interior of the area, determine the diffusion mode of the particles in the spatial range, and obtain the anion release path characteristics. S402: Based on the characteristics of the anion release path, compare the trajectory arrangement of chloride ions in the same spatial range, analyze the movement order, direction change and position distribution of the trajectory during the process of entering the region, determine the proximity relationship between the anion trajectory and the chloride ion trajectory in time and space segments, and obtain the path overlap trend characteristics. S403: Based on the path overlap trend characteristics, screen anion behaviors that are consistent with chloride ion trajectories in terms of directional continuity and distribution of moving segments, analyze whether the trends, extension ranges and dwell times between paths are related, identify trajectory sequences with overlapping behavioral characteristics, and obtain an interference ion screening and annotation map.

7. The method for detecting chloride ion concentration in air according to claim 1, characterized in that, The specific steps of S5 are as follows: S501: Based on the interference ion screening and annotation map, identify the chloride ion trajectory sequence that does not exhibit interference behavior, remove segments in the path that are synchronous with anions in direction and time, analyze the continuous movement state and start and end intervals, and obtain the trajectory sequence range. S502: Based on the trajectory sequence range, analyze the path distribution between chloride ion particles, identify the spatial intersection and temporal overlap behavior in the trajectory, determine the spacing relationship between the start and end points and the dwell segment, eliminate path segments with associated features, and filter the trajectory content that moves under different positions and time intervals to obtain the interference-free trajectory interval. S503: Based on the interference-free trajectory range, extend the spatial migration behavior of chloride ions, locate the corresponding trajectory coverage area and the volume distribution in the air sample, analyze the frequency and continuity of particle trajectories in the volume range, and obtain the detection results of chloride ion concentration in the air.

8. A device for detecting chloride ion concentration in air, characterized in that, The apparatus is used to implement the method for detecting chloride ion concentration in air according to any one of claims 1-7, the apparatus comprising: The aerosol capture module acquires aerosol particles from an air sample. Under the action of an electric field, the aerosol particles are made to attach to the surface of the capture electrode. The attachment behavior is judged based on the movement trajectory of the particles on the surface. The degree of adhesion between the morphology of the contact area and the direction of residence is analyzed. Trajectory paths that show chloride ion binding characteristics are screened to obtain a list of chloride ion attached particle characteristics. The interface adhesion recognition module tracks the adhesion trend of particles to the liquid surface based on the chloride ion adhesion particle feature list, extracts the unfolding contour in the liquid surface area, analyzes the dwelling behavior and the arrangement position of adjacent particles, and filters the area structure that is continuously distributed on the boundary to obtain the interface dwelling particle distribution structure map. Based on the distribution structure diagram of particles staying at the interface, the migration path extraction module sets up a liquid surface tracking section, obtains the path changes of particles expanding outward, determines whether there are extension interruptions, directional deviations and stagnation trends in the trajectory, locates the set of abnormal actions within the path, and obtains a migration path abnormal block diagram. The interfering ion screening module extracts anion paths within the abnormal area based on the migration path anomaly block map, analyzes the trajectory relationship with chloride ions in the spatial segment, filters behavioral paths that enter the same area in adjacent time periods and show overlapping trajectories, identifies particle trajectories associated with chloride ion behavior interference, and obtains an interfering ion screening annotation map. Based on the interference ion screening and annotation map, the concentration output calibration module extracts the chloride ion trajectory sequence that is not affected by interference, eliminates particle behaviors with path intersections and time repetitions, extends the continuous migration path to the gas sample sampling area, analyzes the density of migration distribution, and obtains the chloride ion concentration detection result in the air.

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