A remote calibration method for particulate matter concentration monitor based on regional inversion

Abstract

The present invention relates to a remote calibration method for a particle concentration monitor based on regional inversion. The data of each high-precision monitoring station is uploaded to a server in real time for regional inversion. When the particle monitor needs to be calibrated, a calibration request is sent to the server. After the calibration request is sent, the server performs remote continuous calibration by passing the inversion result value to the particle monitor until the error between the value of the particle monitor and the inversion value is within 10%. The remote calibration method of the present invention is based on the accuracy data of the monitoring station, improves the accuracy of the inversion result, and greatly simplifies the calibration process of micro-stations in a grid monitoring system.

Description

Technical Field

[0001] The invention belongs to the field of environmental protection, and in particular relates to a remote calibration method for a particle concentration monitor based on regional inversion. Background Art

[0002] To build a geographic information system air quality monitoring, early warning, and forecasting platform, realize grid-based, large-scale joint prevention and control, analyze the source of air pollution, and promote big data monitoring of environmental pollution, low-cost, miniaturized, multi-parameter online ambient air quality monitors are needed as a supplement to the existing national control points. Among them, PM2.5 / PM10 are two measurement parameters, usually measured by light scattering sensors. However, when used for actual concentration measurement, the accuracy of the instrument is difficult to guarantee due to the influence of temperature and humidity. Therefore, the light scattering sensor needs to be calibrated periodically.

[0003] At present, for the calibration of light scattering particle sensors, the sensor needs to be disassembled and taken to a company or calibration center with standard calibration instruments for calibration, using the weight method or a higher-precision instrument comparison calibration method. Since the weight method calibration requires manual weighing, the procedure is cumbersome and time-consuming, with a low degree of automation and high cost. The comparison calibration method is to place the higher-precision instrument and sensor in the same environment, perform synchronous sampling, collect data for a period of time, and then export the high-precision instrument data and the data collected by the sensor, fit a sensor calibration formula through a specific algorithm, and then write the calibration formula into the sensor module. The entire calibration process is cumbersome. If you are not a professional technician, it may often lead to calibration errors, thus affecting actual use. When there are a large number of sensors, the calibration takes a long time.

[0004] Therefore, there is an urgent need to solve the problem of difficult calibration of light scattering particle sensors. Summary of the invention

[0005] The present invention aims to solve the problem of difficulty in calibrating particle sensors in grid monitoring equipment. The present invention proposes a remote calibration method based on regional inversion, which combines high-precision monitoring stations and regional inversion technology to remotely calibrate a large number of particle monitors in the grid monitoring system, thereby reducing costs and time.

[0006] The present invention provides a remote calibration method for a particle monitor based on regional inversion, which comprises:

[0007] Step S1, in a certain area, according to the grid planning, in a certain grid, a number of high-precision monitoring stations and a plurality of particle monitors are installed, and a consistency test is performed before the plurality of particle monitors are installed;

[0008] Step S2, using high-precision monitoring stations to obtain meteorological data such as wind speed and wind direction as well as regional topographic information, and establishing a three-dimensional wind field in the grid area based on an atmospheric dynamics model; combining real-time atmospheric conditions (such as temperature, pressure, humidity) and the location information of the released particle number observation points, and performing regional pollutant emission inversion based on regional inversion technology to obtain a high-resolution emission inventory;

[0009] Step S3, using the concentration data and emission source distribution data uploaded by each high-precision monitoring station, analyzing the emission data in each grid, and storing the corresponding data on the server;

[0010] Step S4, the particle monitor initiates a calibration request through the server according to the calibration cycle or initiates a calibration request at any time. The server transmits the inversion result value to the particle monitor for remote continuous calibration until the error between the particle monitor value and the inversion value is within 10%.

[0011] Each particle monitor has unique coordinates within the grid system.

[0012] Wherein, in step S4, the server remotely calibrates the particle monitor by assigning values ​​to five concentration points every two hours or one hour until the error between the value of the particle monitor and the inversion value is within 10%.

[0013] Among them, in step S2, the three-dimensional wind field in the grid area under the atmospheric dynamics model is constructed through the meteorological initial and boundary conditions of the grid area, geographical information such as land use and surface type, and environmental parameters such as radiation, soil and microphysical processes.

[0014] There is a predetermined distance between the plurality of particle monitors and adjacent high-precision monitoring stations, and the predetermined distance is less than a certain distance threshold.

[0015] For the grid monitoring system, the present invention calibrates the particle concentration monitor in the network monitoring system based on high-precision monitoring stations and regional inversion technology, and calibrates the light scattering particle sensor using the inversion value based on the high-precision station, thereby realizing accurate remote calibration of the particle monitor. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of remote calibration of the present invention. DETAILED DESCRIPTION

[0017] In order to facilitate the understanding of the present invention, embodiments of the present invention are described below in conjunction with the accompanying drawings. Those skilled in the art should understand that the following description is only for the convenience of explaining the invention and is not intended to be a specific limitation on the scope of the invention.

[0018] According to the grid planning in a certain area, several high-precision monitoring stations and multiple particulate matter monitors are installed in a certain grid. There is a predetermined distance between the multiple particulate matter monitors and adjacent high-precision monitoring stations. The predetermined distance is less than a certain distance threshold to ensure a coordinated relationship between the high-precision monitoring station and the surrounding multiple particulate matter monitors. Preferably, the distance threshold is between 1-2km, and further preferably, the threshold is 1Km, 1.5Km or 2Km.

[0019] Before installing the multiple particle monitors, a consistency test is performed, specifically:

[0020] a) Test the particle sensor. Select a batch of particle sensors to be installed and conduct parallel comparison. The measurement results between the particle sensors must be consistent, and the relative standard deviation of the PM10 readings should not exceed 20%, and the relative standard deviation of the PM2.5 readings should not exceed 15%. Then test the drift of the particle sensor itself, manually calibrate the sensor, and continue testing until the sensor drifts again, to determine the calibration cycle of the particle sensor.

[0021] b) Based on the test results, a particle monitor housing is provided, and a calibration module including a particle sensor and a monitoring module for meteorological and operating parameters such as temperature, humidity, wind speed and direction are installed in the interior space of the housing. Other electronic devices are also arranged in the interior space of the housing. After the installation is completed, a particle monitor can be obtained.

[0022] c) Carry out correlation analysis between the particle monitor and the high-precision station. Specifically, the particle monitor and the high-precision station can be used for on-site synchronous sampling, and synchronous sampling can be performed at different pollution levels. The concentration span during synchronous sampling is required to be (0-200) μg / m 3 ,Then the sensor and the measurement data of the high-precision station are compared to obtain the correlation between the two.

[0023] d) Installing particle monitors at predetermined locations within the grid monitoring system, each particle monitor having unique coordinates within the grid system.

[0024] As an embodiment, it is preferred to set up 4-5 high-precision monitoring stations and multiple particulate matter monitors in a grid. The data of each high-precision monitoring station is uploaded to the server in real time for regional inversion. The particulate matter concentration value in each grid can be obtained by combining the current wind speed and direction, geographical location and other information.

[0025] Specifically, firstly, high-precision monitoring stations are used to obtain meteorological data such as wind speed and direction, as well as regional topographic information. Combined with real-time atmospheric conditions (such as temperature, pressure, humidity) and the location information of the released particle number observation points, regional pollutant emissions are inverted based on regional inversion technology to obtain a high-resolution emission inventory.

[0026] Obtain the contribution rate of different locations at different times to the concentration of the monitoring station to form emission source distribution data;

[0027] After that, the emission data in each grid is analyzed using the concentration data uploaded by each high-precision monitoring station and the emission source distribution data inverted in the region, and the corresponding data is stored on the server;

[0028] Geostatistical methods are introduced into the regional inversion analysis, and mathematical tools such as variogram and variance matrix are used to study the distribution characteristics of atmospheric particles that are both random and structured in spatial distribution, or have spatial correlation and dependence, so as to reduce or even eliminate the dependence of the inversion process on the initial values ​​of the bottom-up emission inventory, and obtain accurate spatiotemporal distribution of pollutant emissions through rigorous statistical methods.

[0029] When the particle monitor is working, a calibration request can be initiated through the server according to the calibration cycle, or at any time. Each particle monitor in the grid corresponds to a unique coordinate. When calibration is required, a calibration request is initiated to the server. After the calibration request is initiated, the server transmits the inversion result value to the particle monitor for remote continuous calibration until the error between the particle monitor value and the inversion value is within 10%.

[0030] As a further preference, the server periodically assigns the inversion value in the corresponding grid to the particle monitor according to the coordinate position of the particle monitor, such as every two hours or one hour, remote calibration of the particle monitor is achieved by assigning values ​​at five concentration points until the error between the value of the particle monitor and the inversion value is within 10%.

[0031] The remote calibration method for the particle concentration monitor proposed in the present invention is based on a high-precision monitoring station, which can be a national control station or an aerial station. Based on the accuracy data of the monitoring station, the accuracy of the inversion result is improved, and the calibration process of the micro-station in the grid monitoring system is greatly simplified.

[0032] It is to be understood that, although the present invention has been disclosed as a preferred embodiment, the above embodiment is not intended to limit the present invention. For any person skilled in the art, without departing from the scope of the technical solution of the present invention, the technical content disclosed above can be used to make many possible changes and modifications to the technical solution of the present invention, or modified into equivalent embodiments of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of protection of the technical solution of the present invention.

Claims

1. A remote calibration method for a particle concentration monitor based on regional inversion, characterized in that: Step S1, in a certain area, according to the grid planning, in a certain grid, install several high-precision monitoring stations and multiple particle monitors, and before installing the multiple particle monitors, a consistency test is performed; wherein, a batch of particle sensors to be installed are selected for parallel comparison, requiring the measurement results between the particle sensors to be consistent, the relative standard deviation of the PM10 readings is not more than 20%, and the relative standard deviation of the PM2.5 readings is not more than 15%; then test the drift of the particle sensor itself, manually calibrate the sensor and continue the test until the sensor drifts again, and determine the calibration period of the particle sensor; according to the test results, provide a particle monitor housing, and place the particle sensor containing the particle sensor in a container. The calibration module of the particle sensor, including the monitoring module of meteorological and working condition parameters such as temperature and humidity, wind speed and direction, is installed in the inner space of the shell, and other electronic devices are also arranged in the inner space of the shell. After the installation is completed, a particle monitor can be obtained; the particle monitor is subjected to correlation analysis with the high-precision station; the particle monitor and the high-precision station are subjected to on-site synchronous sampling, and synchronous sampling is performed at different pollution levels, and the concentration span during synchronous sampling is required to be; 0-200μg / m3, and then the measurement data of the sensor and the high-precision station are compared to obtain the correlation between the two; the particle monitor is installed at a predetermined position in the grid monitoring system, and each particle monitor has a unique coordinate in the grid system; Step S2, using high-precision monitoring stations to obtain meteorological data such as wind speed and wind direction as well as regional topographic information, combined with real-time atmospheric conditions and the location information of the released particle number observation points, and based on regional inversion technology, perform pollutant emission inversion in the region to obtain a high-resolution emission inventory; Step S3, using the concentration data and emission source distribution data uploaded by each high-precision monitoring station, analyzing the emission data in each grid, and storing the corresponding data on the server; In step S4, the particle monitor initiates a calibration request through the server according to the calibration cycle or initiates a calibration request at any time. The server performs remote continuous calibration by transmitting the inversion result value to the particle monitor until the error between the value of the particle monitor and the inversion value is within 10%.

2. The method for remote calibration of a particle concentration monitor based on regional inversion according to claim 1, characterized in that: In step S4, the server remotely calibrates the particle monitor by assigning values ​​to five concentration points every two hours or one hour until the error between the value of the particle monitor and the inversion value is within 10%.

3. The method for remote calibration of a particle concentration monitor based on regional inversion according to claim 1, characterized in that: In step S2, the three-dimensional wind field in the grid area under the atmospheric dynamics model is constructed through the meteorological initial and boundary conditions of the grid area, geographic information such as land use and surface type, and environmental parameters such as radiation, soil and microphysical processes.

4. The method for remote calibration of a particle concentration monitor based on regional inversion according to claim 1, characterized in that: There is a predetermined distance between the plurality of particle monitors and adjacent high-precision monitoring stations, and the predetermined distance is less than a certain distance threshold.

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