Aerosol mass concentration calculation method and device, medium and computer equipment

Abstract

The invention provides an aerosol mass concentration calculation method and device, a medium and computer equipment, and the method comprises the following steps: after focusing an aerosol sample into a particle beam by using a sample introduction module, receiving a double-peak diameter measurement signal generated when sample introduction particles in the particle beam reach a first position of a diameter measurement module; analyzing the sample introduction particles by using a mass spectrum module to obtain mass spectrum data; calculating original source analytic distribution of the single-category particles based on the mass spectrum data; performing quantity correction on the original source analytic distribution by using a double-peak diameter measurement signal to obtain real source analytic distribution of single-category particles; based on the real source analysis distribution, calculating the mass concentration of the single-class particles; according to the method, original source analysis data of a certain particulate matter is corrected in each particle size section range, and the real particle size distribution of the single type of particulate matter in an aerosol sample is calculated, so that the mass concentration of the particulate matter is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of aerosol mass spectrometry analysis, and more specifically, to an aerosol mass concentration calculation method, device, medium and computer equipment. Background Art

[0002] Source Apportionment refers to the use of various scientific methods and techniques to determine the sources of atmospheric pollutants (such as aerosols, particulate matter, gaseous pollutants, etc.) and their relative contributions. The different particle sizes of particles of the same substance in aerosols are mainly due to various physical and chemical factors in the formation and evolution process. Taking nitrate aerosols as an example, nitrogen oxides (NOx) from automobile exhaust are oxidized to form nitrate particles, which are usually small in size, mostly between 0.1 and 1 micron. Ammonia released during agricultural fertilization reacts with acidic substances in the atmosphere to form nitrate particles, which may be larger in size, mostly between 1 and 5 microns. Therefore, by analyzing the particle size distribution of particles of a certain substance in aerosols, the main source of the substance can be calculated, which in turn provides an important basis for formulating corresponding control measures (such as motor vehicle restrictions, coal-fired transformation, industrial emission control, etc.).

[0003] In summary, obtaining the true particle size distribution of various particles from aerosols is of great significance for the analysis of environmental pollution. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide an aerosol mass concentration calculation method, device, medium and computer equipment to overcome the defect of the prior art that it is difficult to obtain the true particle size distribution from the aerosol.

[0005] The above technical objectives of the present invention are achieved through the following technical solutions: a method for calculating aerosol mass concentration, applied to a single-particle aerosol mass spectrometer source analysis device, the source analysis device comprising: a sampling module, a diameter measurement module and a mass spectrometer module; the mass concentration calculation method specifically comprises:

[0006] After the aerosol sample is focused into a particle beam using the sampling module, a double-peak diameter measurement signal generated by the sampled particles in the particle beam arriving at the first position of the diameter measurement module is received, wherein the double-peak diameter measurement signal is generated after the sampled particles arriving at the first position are irradiated by the first laser unit in the diameter measurement module;

[0007] Using the mass spectrometry module to analyze the injected particles to obtain mass spectrometry data;

[0008] Based on the mass spectrometry data, the original source-analyzed distribution of the single-category particles is calculated; and using the bimodal diameter measurement signal, the original source-analyzed distribution is quantitatively corrected to obtain the true source-analyzed distribution of the single-category particles;

[0009] Based on the true source-analyzed distribution, the mass concentration of a single type of particles is calculated.

[0010] In one embodiment, the laser generated by the first laser unit is two parallel laser beams; the receiving of the double-peak diameter measurement signal generated by the sampled particles in the particle beam arriving at the first position of the diameter measurement module specifically includes: respectively receiving two first light signals generated by each of the sampled particles passing through the two parallel laser beams in sequence, and generating a double-peak diameter measurement signal based on the time difference between the two first light signals.

[0011] In one embodiment, the original source resolved distribution of a single category of particles is calculated based on the mass spectrometry data, specifically comprising: determining the particle type of each ionized sampled particle and the number of particles corresponding to each particle type based on the mass spectrometry data; determining the original source resolved distribution of each single category of particles based on the particle type of the sampled particles and the number of particles corresponding to each particle type in the mass spectrometry data; the original source resolved distribution is specifically the number of the single category of particles within each particle size range.

[0012] In one embodiment, the bimodal sizing signal is used to perform quantitative correction on the original source-analyzed distribution to obtain a true source-analyzed distribution of single-category particles, specifically including: calculating the statistical efficiency in each particle size range based on the bimodal sizing signal and the mass spectrometry data; calculating the ratio of the target number of each particle type in the original source-analyzed distribution in each particle size segment to the statistical efficiency corresponding to the particle size segment to obtain the true source-analyzed distribution.

[0013] In one embodiment, the statistical efficiency in each particle size segment is calculated based on the bimodal sizing signal and the mass spectrum data, specifically including: generating a bimodal particle size distribution corresponding to the injected particles based on the time difference between the bimodal sizing signals; generating a mass spectrum particle size distribution based on the particle information in the mass spectrum data and the bimodal sizing distribution; and calculating the statistical efficiency in each particle size segment based on the bimodal sizing distribution and the mass spectrum particle size distribution.

[0014] In one embodiment, the use of the mass spectrometry module to analyze the injected particles to obtain mass spectrometry data specifically includes: calculating the flight speed of the injected particles based on the time difference between the two first light signals and the distance between the two parallel laser beams; calculating the ionization time when the injected particles reach the ionization position based on the flight speed of the injected particles; according to the ionization time, emitting ionization laser to ionize the injected particles to generate ions, measuring the mass-to-charge ratio of the ions, and obtaining the mass spectrometry data of the injected particles.

[0015] In one embodiment, the mass concentration of a single type of particles is calculated based on the real source analysis distribution, specifically comprising: quantitatively analyzing the aerosol sample based on the real source analysis distribution to obtain the real mass concentration ρ corresponding to any substance in all particle size ranges N_Mj , the true mass concentration ρ corresponding to all substances within any particle size range N_di And the total mass concentration of all substances in all particle size ranges ρ N .

[0016] An aerosol mass concentration calculation device, the source analysis device specifically comprising:

[0017] An optical signal receiving module: after the aerosol sample is focused into a particle beam by using the sampling module, the optical signal receiving module receives a double-peak diameter measurement signal generated when the sampled particles in the particle beam arrive at the first position of the diameter measurement module, wherein the double-peak diameter measurement signal is generated after the first laser unit in the diameter measurement module irradiates the sampled particles arriving at the first position;

[0018] Mass spectrometry analysis module: used to use the mass spectrometry module to analyze the injected particles to obtain mass spectrometry data;

[0019] Source analysis calculation and correction module: used to calculate the original source analysis distribution of single-category particles based on the mass spectrometry data, and to perform quantitative correction on the original source analysis distribution using the bimodal diameter measurement signal to obtain the true source analysis distribution of single-category particles;

[0020] Mass concentration calculation module: used to calculate the mass concentration of a single category of particles based on the true source analysis distribution.

[0021] A computer-readable storage medium stores a computer program, which implements the steps of the above method when executed by a processor.

[0022] A computer device comprises a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above method when executing the computer program.

[0023] In summary, the present invention has the following beneficial effects: the method measures the first kinetic particle size of the particulate matter to obtain the first particle size distribution of the particulate matter, then measures the second kinetic particle size of the particulate matter to obtain the second particle size distribution of the particles, and unifies the two particle size distributions to the volume equivalent diameter scale, thereby obtaining the particle size statistical efficiency of the source analysis device in different particle size ranges. By using the method of the present application, the original source analysis data of a certain particle can be corrected within each particle size range in the process of using a high-precision single-particle aerosol mass spectrometer, and the true particle size distribution of a single category of particles in the aerosol sample can be calculated. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A flow chart of a method for calculating aerosol mass concentration of the present invention;

[0025] Figure 2 It is a structural diagram of an aerosol mass concentration calculation device of the present invention;

[0026] Figure 3 is an internal structure diagram of a computer device in an embodiment of the present invention;

[0027] Figure 4 Schematic diagram of the structure of a SOMS device for aerosol source analysis in an embodiment of the present invention;

[0028] Figure 5 It is a schematic diagram of the ratio of the double-peak diameter measurement signal and the mass spectrum data within each particle size range of the present invention;

[0029] Figure 6 It is a schematic diagram of correcting the original source parsed distribution to obtain the true source parsed distribution according to the present invention.

[0030] In the figure, 1. aerodynamic lens; 2. optical signal receiver; 3. first laser transmitter; 4. convex lens; 5. concave reflector; 6. beam splitter; 7. mass spectrometry equipment; 8. ionization laser; 9. reflector; 10. optical signal receiving module; 11. mass spectrometry module; 12. source resolution calculation and correction module; 13. mass concentration calculation module. DETAILED DESCRIPTION

[0031] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings. Several embodiments of the present invention are shown in the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein.

[0032] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. The terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0033] In the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, the first feature being "above", "above" and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature. The terms "vertical", "horizontal", "left", "right", "above", "below" and similar expressions are for illustrative purposes only, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0034] The present invention is described in detail below in conjunction with the accompanying drawings and embodiments. In order to facilitate the understanding of the embodiments, the relevant technology is first described. In the prior art, the number concentration of particulate matter is currently measured mainly by an optical particle counter, among which the aerodynamic particle sizer (Aerodynamic Particle Sizer) is referred to as APS, which is an instrument for measuring the aerodynamic particle size distribution of particulate matter and is widely used in particulate matter measurement. APS focuses particles through an aerodynamic lens, accelerates the airflow through an accelerating nozzle, and generates a particle beam with a certain flight speed. Particles of different particle sizes in the airflow will produce different accelerations due to inertia. After the particles fly out of the nozzle, two parallel laser beams generate light scattering signals in the detection area. The scattering signals are converted into electrical pulse signals through a photoelectric detector. Each particle generates two separate signals, and the flight time of the particles passing through the two laser beams can be obtained. Then, the flight time is calculated one-to-one with the particle size according to the formula to obtain the particle size distribution characteristics. However, APS cannot measure the chemical composition information of particulate matter, let alone provide the chemical composition information of a single particle. Therefore, it is not suitable for accurate particle source analysis.

[0035] Single particle aerosol mass spectrometer (SPMS), SPMS can measure the diameter and analyze the chemical composition of a single particle to solve the defects of APS equipment. The existing SPMS focuses the particles into a collimated particle beam through an aerodynamic lens. When the particles leave the exit of the aerodynamic lens, a velocity distribution related to the particle size will be generated. Then in the diameter measurement area, two laser beams that converge at a certain distance are used to generate particle scattered light. The photomultiplier tube measures the time difference between the two scattered light beams to know the flight speed of the particles, thereby obtaining the aerodynamic particle size of the particles. At the same time, the speed of the particles will also be used to accurately trigger the downstream ionization laser, so that the particles will be ionized at the exact time when the particles reach the ion source. This process can obtain the particle size and chemical composition of a single particle. Since the chemical composition of the particles is closely related to the source of the particles, the mass spectrum characteristics of a single particle can be regarded as the fingerprint characteristics of the particles, so as to analyze the source of the particles. After a period of time, such as half an hour of sampling, SPMS can obtain information on the particle size and chemical composition of tens of thousands of single particles. By classifying these large quantities of particulate matter, the proportion of different types of particulate matter and their changes over time can be obtained. This information on changes provides extremely important reference value for understanding the change process of particulate matter, how to control particulate matter pollution, and the evaluation of particulate matter control measures. Therefore, SPMS plays an important role in the analysis of atmospheric particulate matter sources.

[0036] Although the use of SPMS equipment can obtain the particle size distribution and chemical composition of particles, it plays an important role in the analysis of aerosols. However, in actual use, due to the difference in the transmission efficiency of the equipment for particles of different particle sizes, the source analysis distribution of single-category particles measured by the equipment is difficult to reflect the true distribution of aerosol particles. A Chinese invention patent (patent number ZL201910043196.5) discloses a real-time quantitative analysis method for single-particle aerosols. In this application, the measurement results of some foreign equipment such as semi-continuous atmospheric monitors and beta-ray particle continuous monitors are used as standard results. The concept of strike rate is introduced to correct the sum of the peak areas of each component obtained by the SPAMS instrument analysis, improve the correlation between the corrected peak area and the mass concentration of the particles, and then calculate the mass concentration of the particles through the peak area, so as to achieve quantitative analysis of aerosol particles in a certain particle size segment.

[0037] However, the application still has the following defects: the single particle aerosol mass spectrometer used in the application is model: SPAMS 0515 (produced by Guangzhou Hexin Analytical Instrument Co., Ltd.), which uses two parallel lasers to measure the particle size in the focused particle beam. Due to the phenomenon of particles overtaking each other in the process of measuring the size and the low measurement accuracy, the number of particles that can be ionized is extremely small, the particle loss is large, and the number of particles that can be ionized and obtain mass spectrum data is extremely small. According to the appendix of the description of the application, Figure 2 a and instructions Figure 2 From the order of magnitude of the ordinate in b, it can be seen that there is a difference of nearly 10 times between CPA (sum of peak areas after correction) and PA (sum of peak areas before correction), and there will be certain losses in the process from the aerosol passing through the aerodynamic lens into the sizing module to the completion of sizing. Therefore, the strike rate obtained by calculating the ratio of the number of particles that simultaneously obtain particle size and mass spectrum information to the number of all particles containing particle size information in this application cannot reflect the true number concentration of particulate matter in the atmosphere.

[0038] In addition, the application also uses the mass concentration measured by some foreign equipment as standard data, and correlates the number concentration corrected by the equipment with the mass concentration to prove the effectiveness of the strike rate calculation. This method has the following problems: first, the mass concentration of aerosol particles measured by instruments is affected by many factors, and it is difficult to determine whether the data measured by the equipment is accurate; second, the correlation between the peak area and the mass concentration after the strike rate correction is still difficult to be considered strong. For example, in the particle size range of PM2.5, the K after the strike efficiency correction is + , Ca + Mg 2+ 、Na +The correlation coefficients with the test results of the standard equipment were only 0.77, 0.78, 0.39 and 0.47.

[0039] Embodiment 1

[0040] In order to solve the above problems, the present invention provides a method for calculating aerosol mass concentration based on a single-particle aerosol mass spectrometer source analysis method. Figure 1 As shown, it is applied to a single-particle aerosol mass spectrometer source analysis device, the source analysis device includes: a sampling module, a diameter measurement module and a mass spectrometry module; the mass concentration calculation method specifically includes:

[0041] S1, after focusing the aerosol sample into a particle beam using the sampling module, receiving a double-peak diameter measurement signal generated when the sampled particles in the particle beam arrive at the first position of the diameter measurement module, wherein the double-peak diameter measurement signal is generated after the first laser unit in the diameter measurement module irradiates the sampled particles arriving at the first position;

[0042] S2, using the mass spectrometry module to analyze the injected particles to obtain mass spectrometry data;

[0043] S3, calculating the original source-analyzed distribution of the single-category particles based on the mass spectrometry data; and using the bimodal diameter measurement signal, quantitatively correcting the original source-analyzed distribution to obtain the true source-analyzed distribution of the single-category particles;

[0044] S4. Calculate the mass concentration of a single type of particles based on the true source analysis distribution.

[0045] In order to improve the success rate of diameter measurement, the mass concentration calculation method of this application is based on Figure 4 A single-particle mass spectrometry device is shown, and the single-particle aerosol mass spectrometry device includes an injection module, a diameter measurement module and a mass spectrometry module. The injection module is used to focus the particles in the aerosol into a particle beam. In this embodiment, the injection module can use an aerodynamic lens or a nozzle; the diameter measurement module is used to measure and count the particles in the particle beam, and the mass spectrometry module is used to perform mass spectrometry analysis on the particles in the particle beam to determine the type of particles. When the source analysis is finally performed, the particle size of each substance can be identified separately according to the mass spectrometry data, and then the distribution of the actual source of the substance can be determined.

[0046] In order to make the measured data closer to the real data, the data actually measured by the device needs to be calibrated. Before calibration, the calibration parameters of the device need to be calculated according to the measurement principle of the device, and then the measurement results of the device need to be calibrated.

[0047] In the prior art, the transmission efficiency of the aerodynamic lens in the process of transmitting aerosol particles of 0.1 to 10 μm can be as high as 95% or more. Therefore, the aerosol particles transmitted to the diameter measurement module through the aerodynamic lens can be approximately regarded as having the same particle size distribution characteristics as the particles in the atmosphere. In summary, the loss of particles in the process of the aerodynamic lens transmitting particles is not obvious. The traditional SPMS equipment uses two parallel laser beams for diameter measurement, and the time when the particles reach the second laser beam is also used to calculate the trigger time of the ionization laser. That is, when the particles are successively irradiated by the two laser beams, two laser scattered light signals will be generated. By calculating the time difference between the two signals, the flight speed of the sampled particles, the kinetic particle size of the particles, and the precise time when the particles fly to the ionization position can be inferred, so that the measured particles can be hit by the ionization laser at the ionization position and ionized, so as to measure their mass-to-charge ratio in the subsequent mass spectrometry analysis. The speed of the particles output by the aerodynamic lens is different. There will be a phenomenon of particles catching up during the diameter measurement process. There is a difference between the speed calculated after passing through two lasers and the speed of the actual particles. The ionization laser cannot accurately ionize the particles, which affects the quantitative statistics of the final particle mass spectrum and the correspondence between the mass spectrum data and the particles. In order to solve the above problems, the present application proposes a new calculation method that can calculate the mass concentration of aerosols. First, the number of particles and the diameter of the particles in the aerosol sample are preliminarily measured through a bimodal diameter measurement signal. Based on the previous content, it can be seen that the counting result of the bimodal diameter measurement signal can be approximately regarded as the number of particles in the aerosol sample. Although the accuracy of the particle size measured by the bimodal diameter measurement signal is low, it can also meet the statistical requirements of the particle size range, because the particle size range is originally a relatively wide range. Although there is an error in the particle size measurement, as long as the error is much smaller than the particle size range, it can meet the needs of the quantitative statistics of the particle size range. Therefore, the particle size distribution of all particles in the aerosol sample can be obtained through the bimodal diameter measurement signal. Then, based on the interval time of the double-peak diameter measurement signal and the distance between the two lasers that generate the double-peak diameter measurement signal, the flight speed of the particle can be calculated, and then the time when the particle enters the mass spectrometer can be determined. Then, the ionization laser is emitted at a specific time to ionize the particle. When the particle is ionized, the mass-to-charge ratio of the particle is measured to obtain the type of particle. Since the data of the particle is bound to the particle, when the mass spectrometry data of the particle is obtained, the particle size distribution of the particle obtained by the mass spectrometry data can also be established. Without distinguishing the type of particle, the particle transmission efficiency of each particle size segment can be calculated according to the number of particles distributed in each particle size segment. Using the particle transmission efficiency of each particle size segment, based on the particle size distribution of the single-category particle obtained by the mass spectrometry data, the single-category particle is corrected in each particle size segment using the transmission efficiency, and the particle size distribution of the single-category particle in the aerosol sample can be obtained, that is, the true source analysis distribution.Using the true source resolved distribution, combined with the average particle size of each size range and the average density of a single type of particle, the true mass concentration of the particulate matter can be calculated.

[0048] In summary, this application proposes a method for calculating the mass concentration of aerosol particles. By correcting the original source parsed distribution to obtain the true source parsed distribution, and then using the true source parsed distribution to determine the mass concentration of each type of particulate matter, the mass concentration of a single category of particulate matter can be obtained more accurately.

[0049] In one embodiment, the laser generated by the first laser unit is two parallel laser beams; the receiving of the double-peak diameter measurement signal generated by the sampled particles in the particle beam arriving at the first position of the diameter measurement module specifically includes: respectively receiving two first light signals generated by each of the sampled particles passing through the two parallel laser beams in sequence, and generating a double-peak diameter measurement signal based on the time difference between the two first light signals.

[0050] The double-peak sizing signal is the scattered light signal generated after the sampled particles pass through two parallel lasers in sequence. It is reflected on the signal receiver as two peak-shaped signal points. The time interval between the two peak-shaped signal points is the time interval for the particles to pass through the two lasers. Then, based on the distance between the two lasers, the flight speed of the particles can be calculated. Since the flight speed of the particles is in a corresponding relationship with the dynamic diameter of the particles, the particle size distribution of the sampled particles of the aerosol sample can be obtained by counting the number of double-peak sizing signals and the time difference between the double-peak sizing signals. At this time, the particle size distribution does not distinguish between the types of particles. The particles are mixed with each other, so the particles can be regarded as uniformly mixed. In the subsequent ionization process, the particles that are not ionized can also be regarded as uniformly lost, so the category ratio of the particles can remain unchanged.

[0051] In one embodiment, the use of the mass spectrometry module to analyze the injected particles to obtain mass spectrometry data specifically includes: calculating the flight speed of the injected particles based on the time difference between the two first light signals and the distance between the two parallel laser beams; calculating the ionization time when the injected particles reach the ionization position based on the flight speed of the injected particles; according to the ionization time, emitting ionization laser to ionize the injected particles to generate ions, measuring the mass-to-charge ratio of the ions, and obtaining the mass spectrometry data of the injected particles.

[0052] In practical applications, the mass spectrometry process requires the particles to be ionized first, such as Figure 4 As shown, particles enter the mass spectrometer, and the ionization laser in the mass spectrometer ionizes the particles that reach the ionization position to generate ions. After the ions fly in the mass spectrometer, they fall onto the receiving device to generate mass-to-charge ratio data.

[0053] In one embodiment, the original source resolved distribution of a single category of particles is calculated based on the mass spectrometry data, specifically comprising: determining the particle type of each ionized sampled particle and the number of particles corresponding to each particle type based on the mass spectrometry data; determining the original source resolved distribution of each single category of particles based on the particle type of the sampled particles and the number of particles corresponding to each particle type in the mass spectrometry data; the original source resolved distribution is specifically the number of the single category of particles within each particle size range.

[0054] In the process of acquiring mass spectrometry data, the mass-to-charge ratio data of each particle can correspond one-to-one with the double-peak signal obtained by the parallel laser. Therefore, after obtaining the mass spectrometry information of the particle, the particle size data of the particle can also be traced back, that is, the type and particle size of each particle can be obtained. Then, the sampled particles are first classified based on the type of particle, and then the particle size distribution of each type of particle is analyzed to obtain the original source analysis distribution of the single-type particle.

[0055] In one embodiment, the bimodal sizing signal is used to perform quantitative correction on the original source-analyzed distribution to obtain a true source-analyzed distribution of single-category particles, specifically including: calculating the statistical efficiency in each particle size range based on the bimodal sizing signal and the mass spectrometry data; calculating the ratio of the target number of each particle type in the original source-analyzed distribution in each particle size segment to the statistical efficiency corresponding to the particle size segment to obtain the true source-analyzed distribution.

[0056] In practical applications, since the injected particles do not distinguish between the types of particles and the particles are mixed with each other, the particles can be regarded as uniformly mixed. In the subsequent ionization process, the particles that are not ionized can also be regarded as uniformly lost. Therefore, the category ratio of particles can remain unchanged. Based on the overall statistical efficiency, the original source-analyzed distribution of single-category particles can be corrected separately to obtain the true source-analyzed distribution.

[0057] In one embodiment, the statistical efficiency in each particle size segment is calculated based on the bimodal sizing signal and the mass spectrum data, specifically including: generating a bimodal particle size distribution corresponding to the injected particles based on the time difference between the bimodal sizing signals; generating a mass spectrum particle size distribution based on the particle information in the mass spectrum data and the bimodal sizing distribution; and calculating the statistical efficiency in each particle size segment based on the bimodal sizing distribution and the mass spectrum particle size distribution.

[0058] In one embodiment, the mass concentration of a single type of particles is calculated based on the real source analysis distribution, specifically comprising: quantitatively analyzing the aerosol sample based on the real source analysis distribution to obtain the real mass concentration ρ corresponding to any substance in all particle size ranges N_Mj , the true mass concentration ρ corresponding to all substances within any particle size range N_di And the total mass concentration of all substances in all particle size ranges ρ N .

[0059] Specifically, calculate the true mass concentration ρ corresponding to any substance in all particle size ranges N_Mj ,include:

[0060]

[0061] Among them, N i represents the total number of particles in the mass spectrometry data within the i-th particle size range; a i,j represents the proportion of the jth substance in the i-th particle size range; Q represents the injection flow rate of the instrument, in L / min; η i represents the statistical efficiency within the i-th particle size range; d i Represents the average particle size within the i-th particle size range.

[0062] Specifically, calculate the true mass concentration ρ corresponding to all substances within any particle size range N_di ,include:

[0063]

[0064] Among them, N i represents the total number of particles in the mass spectrometry data within the i-th particle size range; d i represents the average particle size within the i-th particle size range; a i,j represents the proportion of the jth substance in the i-th particle size range; ρ j Represents the density of the jth substance in g / m 3 ; Q represents the sample flow rate of the instrument, in L / min; η i Represents the statistical efficiency within the i-th particle size range.

[0065] Specifically, calculate the total mass concentration ρ corresponding to all substances in all particle size ranges N ,include:

[0066]

[0067] Among them, N irepresents the total number of particles in the mass spectrometry data within the i-th particle size range; d i represents the average particle size within the i-th particle size range; a i,j represents the proportion of the jth substance in the i-th particle size range; ρ j Represents the density of the jth substance in g / m 3 ; Q represents the sample flow rate of the instrument, in L / min; η i Represents the statistical efficiency within the i-th particle size range.

[0068] In summary, the present application proposes a method for calculating aerosol mass concentration. By calculating the statistical efficiency of the injected particles in each particle size segment, the number of single-category particles in each particle size segment is corrected, and then the actual number of single-category particles in each particle size segment is obtained, and the true source-analyzed distribution of single-category particles is obtained, and finally the true mass concentration of the target particles can be calculated.

[0069] Embodiment 2

[0070] Applied to a single-particle aerosol mass spectrometer, the single-particle aerosol mass spectrometer comprises: a sampling module, a diameter measurement module and a mass spectrometer module; the mass concentration calculation method specifically comprises:

[0071] S1. After the aerosol sample is focused into a particle beam using the sampling module, a double-peak diameter measurement signal generated when the sampled particles in the particle beam arrive at the first position of the diameter measurement module and a second diameter measurement signal generated when the particles to be analyzed in the particle beam arrive at the second position of the diameter measurement module are received; wherein the double-peak diameter measurement signal is generated when the first laser unit in the diameter measurement module irradiates the particles arriving at the first position, and the second diameter measurement signal is generated when the second laser unit in the diameter measurement module irradiates the particles arriving at the second position;

[0072] S2, emitting an ionization laser based on the second diameter measurement signal to ionize the particles to be analyzed into ions, and using the mass spectrometry module to analyze the ions to obtain mass spectrum data of the ions;

[0073] S3, calculating the original source-analyzed distribution of the single-category particles based on the mass spectrum data, and performing quantitative correction on the original source-analyzed distribution using the bimodal caliper signal and the second caliper signal to obtain the true source-analyzed distribution of the single-category particles;

[0074] S4. Calculate the mass concentration of a single type of particles based on the true source analysis distribution.

[0075] Specifically, compared with the first embodiment, the present embodiment is additionally provided with a second laser unit, and the second laser unit is used to further identify the particle size of the particles on the basis of the double-peak diameter measurement signal, as follows: First, the number of particles and the diameter of the particles in the aerosol sample are preliminarily measured through the double-peak diameter measurement signal. Based on the previous content, it can be known that the counting result of the double-peak diameter measurement signal can be approximately regarded as the number of particles in the aerosol sample. Although the accuracy of the particle size measured by the double-peak diameter measurement signal is low, it can also meet the statistical requirements of the particle size range, because the particle size range is originally a relatively wide range. Although there is an error in the particle size measurement, as long as the error is much smaller than the particle size range, it can meet the needs of the number statistics of the particle size range. Therefore, the particle size distribution of all particles in the aerosol sample can be obtained through the double-peak diameter measurement signal. Then, the particles are controlled to arrive at the second position, and are irradiated by the second diameter measurement laser at the second position to generate a second diameter measurement signal. The purpose of setting the second diameter measurement signal in the present application is to determine the specific time point when the particles arrive at the ionization position by measuring the flight time of the particles, so as to accurately ionize the particles. In addition, the diameter of the particles can be further accurately measured by using the bimodal sizing signal and the second sizing signal. Please refer to the subsequent content for the specific calculation process. The particles after laser ionization finally enter the mass spectrometry module to measure the properties of the particles in order to determine the type of particles and count the number of each particle. Through the above steps, the true source analysis distribution of the particles corresponding to each substance in the aerosol sample can be determined. Using the true source analysis distribution, combined with the average particle size of each particle size range and the average density of a single category of particles, the true mass concentration of the particles can be calculated.

[0076] In order to make the detection result closer to the particle size distribution in the input aerosol, the present application sets a first laser unit and a second laser unit in the diameter measurement module. The laser irradiated by the first laser unit is two parallel laser beams, and the distance between the two parallel laser beams is very small. Therefore, when the particle passes through the area irradiated by the first laser unit, a double-peak diameter measurement signal will be generated. Since the time interval between the two parallel laser beams is known, the first speed of the particle flight can be calculated by dividing the laser interval by the flight time. Since the interval between the laser beams emitted by the first laser unit is very small, the first speed obtained is not an accurate speed, and can be considered as an estimated value, which is used to predict the time required for the particle to reach the position of the laser of the second laser unit. At the same time, because the interval between the two laser beams emitted by the first laser unit is very small, the possibility of multiple particles appearing within the interval is extremely small. It can be understood that when multiple particles pass through the laser within a preset time range, there will be multiple light signals. At this time, it is impossible to distinguish which two light signals are generated by the same particle passing through the two laser beams, so the speed cannot be calculated. Therefore, when more than two optical signals appear, it can be considered that more than two particles pass through two parallel laser beams within the preset time range. We cannot distinguish which particle these optical signals belong to, so the particle corresponding to this optical signal needs to be excluded. In the case of obtaining a double-peak diameter measurement signal, further accurate calculation is performed based on the first speed to obtain the estimated time and estimated range of the particle reaching the second laser position. The distance between the first laser unit and the second laser unit is also known, so the time when the particle reaches the laser emitted by the second laser unit can be calculated based on the first speed. Because the accuracy of the above-mentioned first speed is not high, the time obtained will not be a high-precision time. There are two particles that are far enough apart. When passing through the first laser unit, there are only two signals within the preset time range, so the first laser unit will identify two groups of valid signals. However, the distance between the two particles is smaller than the distance between the first laser unit and the second laser unit. Therefore, when the two particles pass through the laser emitted by the second laser unit, the ownership of the generated optical signal is unknown, making it impossible to accurately calculate the speed of each particle. Therefore, it is necessary to calculate an estimated time and estimated time range of the laser emitted by the second laser unit for each particle that generates a valid signal to distinguish the particles in this case. By adopting the above-mentioned velocity calculation method, the particles passing through the two laser units can be distinguished as much as possible, thereby reducing the number of particles whose velocity cannot be measured.

[0077] In one embodiment, the original source resolved distribution of a single category of particles is calculated based on the mass spectrometry data, specifically comprising: determining the particle type of each ionized sampled particle and the number of particles corresponding to each particle type based on the mass spectrometry data; determining the original source resolved distribution of each single category of particles based on the particle type of the sampled particles and the number of particles corresponding to each particle type in the mass spectrometry data; the original source resolved distribution is specifically the number of the single category of particles within each particle size range.

[0078] In actual applications, when acquiring mass spectrometry data, the mass-to-charge ratio data of each particle can correspond one-to-one with the double-peak signal obtained by the parallel laser. Therefore, after obtaining the mass spectrometry information of the particle, the particle size data of the particle can also be traced back, that is, the type and size of each particle can be obtained. Then, the sampled particles are first classified based on the type of particle, and then the particle size distribution of each type of particle is analyzed to obtain the original source analysis distribution of the single-type particle.

[0079] In one embodiment, the bimodal sizing signal and the second sizing signal are used to perform quantitative correction on the original source-analyzed distribution to obtain a true source-analyzed distribution of single-category particles, specifically including: calculating the statistical efficiency in each particle size range based on the bimodal sizing signal, the second sizing signal and the mass spectrometry data; calculating the ratio of the target number of each particle type in the original source-analyzed distribution in each particle size segment to the statistical efficiency corresponding to the particle size segment to obtain a true source-analyzed distribution.

[0080] In one embodiment, the statistical efficiency in each particle size segment is calculated based on the bimodal sizing signal, the second sizing signal and the mass spectrum data, specifically including: generating a first sizing distribution corresponding to the injected particles based on the time difference between the bimodal sizing signals and the time difference between the second sizing signal and the bimodal sizing signal; generating a mass spectrum particle size distribution corresponding to the particles to be detected based on the number of particles in the mass spectrum data; and calculating the statistical efficiency in each particle size segment based on the first sizing distribution and the mass spectrum particle size distribution.

[0081] In practical applications, since the transmission efficiency of the equipment in each particle size segment is different, when calculating the statistical efficiency, it is necessary to calculate the statistical efficiency separately according to the pre-divided particle size segment range. Then, based on the statistical efficiency corresponding to each particle size segment, the particle size segment range of the original source analysis distribution is corrected separately. And in this application, the transmission speed of the particles is only related to the diameter of the particles, and has nothing to do with the type of particles and the density of particles. Therefore, in this application, the particles of all substances are regarded as a uniformly mixed whole, and only the statistical efficiency of each particle size range of the whole is analyzed, and the statistical efficiency can be regarded as the statistical efficiency of each particle size of a certain substance.

[0082] In one embodiment, the first caliber measurement distribution corresponding to the injected particles is generated based on the time difference between the double-peak caliber measurement signals and the time difference between the second caliber measurement signal and the double-peak caliber measurement signal, specifically including: calculating the first flight speed of each injected particle based on the time difference between the double-peak caliber measurement signals and the distance between two parallel laser beams emitted by the first laser unit; calculating the second flight speed of each injected particle by using the time difference between the double-peak caliber measurement signal and the second caliber measurement signal and the distance between the laser beam emitted by the first laser unit and the laser beam emitted by the second laser unit; calculating the first volume equivalent diameter of the injected particles according to the first flight speed and the second flight speed of each injected particle, counting the number of injected particles in each particle size range, and generating a first particle size distribution.

[0083] In actual applications, when the particles are initially input into the diameter measurement module, all the particles are counted, and only the number of double-peak diameter measurement signals needs to be counted to obtain the number of particles. However, in order to obtain the particle size distribution of the particles, it is necessary not only to obtain the total number of particles but also the particle size of the particles. Using three parallel lasers, the particle speed can be accurately measured, and then the volume equivalent diameter of the particles can be accurately calculated. Then, based on the accurately calculated particle diameter, the first particle size distribution is determined.

[0084] In the present application, most of the particles in the aerosol are between 0.1 μm and 10 μm. Therefore, in order to accurately capture the light signal scattered by the irradiated particles, the laser emitting the laser in the present application is a continuous laser with a wavelength range of 300-1500 nm. The shorter the wavelength, the better the detection performance for small diameter particles.

[0085] The first laser unit emits two parallel lasers, which can be realized by a beam splitter 6. The beam splitter 6 can split the light into two parallel laser beams with a certain distance according to the polarization state of the light. The distance between the two laser beams is related to the thickness and crystal orientation of the crystal. The optical crystal material can be quartz, calcite, yttrium vanadate, etc. Its principle is to utilize the different refractive indexes of light with different polarization properties in the birefringent crystal. Therefore, the beam splitter 6 can generate two parallel polarization states orthogonal light beams with a certain offset. In the present application, the distance between the two lasers generated by the refraction of the beam splitter is about 300μm.

[0086] In one embodiment, the original source resolved distribution of a single category of particles is calculated based on the mass spectrometry data, specifically comprising: determining the particle type of each ionized sampled particle and the number of particles corresponding to each particle type based on the mass spectrometry data; determining the original source resolved distribution of each single category of particles based on the particle type of the sampled particles and the number of particles corresponding to each particle type in the mass spectrometry data; the original source resolved distribution is specifically the number of the single category of particles within each particle size range.

[0087] In the process of acquiring mass spectrometry data, the mass-to-charge ratio data of each particle can correspond one-to-one with the double-peak signal obtained by the parallel laser. Therefore, after obtaining the mass spectrometry information of the particle, the particle size data of the particle can also be traced back, that is, the type and size of each particle can be obtained. Then, the sampled particles are first classified based on the type of particle, and then the particle size distribution of each category of particles is analyzed to obtain the original source analysis distribution of a single category of particles. In one embodiment, the statistical efficiency within each particle size range is calculated based on the first diameter measurement distribution and the mass spectrometry particle size distribution, specifically including:

[0088] Convert the kinetic particle size of each particle into a volume equivalent diameter;

[0089] Recalculating the first diameter distribution based on the volume equivalent diameter of each particle;

[0090] Recalculate the mass spectrometry particle size distribution based on the volume equivalent diameter of each particle;

[0091] The ratio of the number of each particle size segment in the first size distribution to the number of each particle size segment in the mass spectrum particle size distribution is taken as the statistical efficiency of each particle size segment.

[0092] In practical applications, the specific principle of measuring the flight time of particles based on the first laser unit and the second laser unit and then calculating the kinetic particle size of the particles has been explained in detail in the above content and will not be repeated here. Based on the kinetic particle size of the particles and the number of particles, the particle size distribution based on the kinetic particle size can be obtained. The laser distance between the first laser and the second laser is far, so the particle overtaking phenomenon between the lasers is more serious. Since there is a large loss of particles in the kinetic particle size algorithm, the statistical efficiency of particles in each particle size segment can be calculated based on the first diameter measurement distribution and the mass spectrum diameter measurement distribution. In addition, the accuracy of particle size measurement can be further improved based on the bimodal diameter measurement signal and the second diameter measurement signal.

[0093] In this application, the particle size of the particles is based on dynamic particle size statistics, so the particle size needs to be unified to the physical particle size before comparison. The aerodynamic diameter is defined as the diameter of a sphere with a unit density (1g / cm3) that has the same terminal sedimentation rate as the research object. Therefore, the particles have the same dynamic performance as the sphere with a unit density under this diameter. In the active sampling method, the particle size is characterized by the aerodynamic diameter. Aerodynamic diameter d a The conversion to geometric diameter d is calculated by the following formula:

[0094] d = kd a

[0095] Where k is the conversion factor.

[0096] In this application, if Figure 5 As shown in the figure, since particles can be considered as uniformly mixed during transmission, if each type of particle has a particle distribution in this particle size segment, its loss also conforms to the law of statistical efficiency. Therefore, when the original source analysis distribution of a substance is obtained, the original source analysis distribution is corrected using statistical efficiency to obtain the true source analysis distribution of the substance in the aerosol.

[0097] In one embodiment, the counting of the corresponding number of the single-category particles in each particle size segment to generate the original source parsed distribution of the single-category particles also includes: using the ART-2A model to cluster the particle size segments of the single-category particles to generate the original source parsed distribution of the single-category particles.

[0098] Specifically, source analysis distribution is to analyze the source of a single category of particles based on their size. Since the size change of a single category of particles is usually continuous and the source of a single category of particles is also affected by various factors, it is difficult to accurately classify particles under the influence of multiple factors using manual means. The ART-2A model can well perceive the inherent correlation of particles and cluster particles from different sources together. And after clustering is completed, the particle sizes after clustering are corrected according to statistical efficiency to obtain the true source of aerosol particles.

[0099] In one embodiment, the mass concentration of a single type of particles is calculated based on the real source analysis distribution, specifically comprising: quantitatively analyzing the aerosol sample based on the real source analysis distribution to obtain the real mass concentration ρ corresponding to any substance in all particle size ranges N_Mj , the true mass concentration ρ corresponding to all substances within any particle size range N_di And the total mass concentration of all substances in all particle size ranges ρ N For details on how to calculate the mass concentration, please refer to the contents in Example 1 and Example 6.

[0100] Embodiment 3

[0101] See also Figure 2 , an aerosol mass concentration calculation device, the source analysis device specifically comprises:

[0102] The optical signal receiving module 10 is used to receive a double-peak diameter measurement signal generated when the sampled particles in the particle beam reach the first position of the diameter measurement module after the aerosol sample is focused into a particle beam by using the sampled injection module, wherein the double-peak diameter measurement signal is generated after the sampled particles reaching the first position are irradiated by the first laser unit in the diameter measurement module;

[0103] Mass spectrometry analysis module 11: used to use the mass spectrometry module to analyze the injected particles to obtain mass spectrometry data;

[0104] Source analysis calculation and correction module 12: used to calculate the original source analysis distribution of single-category particles based on the mass spectrum data; and to perform quantitative correction on the original source analysis distribution using the bimodal diameter measurement signal to obtain the true source analysis distribution of single-category particles;

[0105] The mass concentration calculation module 13 is used to calculate the mass concentration of a single type of particles based on the true source analysis distribution.

[0106] For the specific definition of an aerosol mass concentration calculation device, please refer to the definition of an aerosol mass concentration calculation method above, which will not be repeated here. Each module in the above-mentioned aerosol mass concentration calculation device can be implemented in whole or in part by software, hardware and a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

[0107] Furthermore, the present application also provides a conversion formula for converting the volume equivalent diameter into the aerodynamic diameter, including:

[0108]

[0109] d ve : volume equivalent diameter; d a : aerodynamic diameter; χ: dynamic shape factor (taken as 1.4 in ambient air); ρ p : true density of the particle; ρ 0 Reference density (usually 1g / cm 3 ).

[0110] Those skilled in the art will understand that Figure 2 The structure shown in the figure is only a block diagram of a part of the structure related to the scheme of the present application, and does not constitute a limitation of the scheme of the present application. A specific aerosol mass concentration calculation device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0111] Embodiment 4

[0112] A computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, an aerosol mass concentration calculation method as described in Example 1 is implemented.

[0113] Embodiment 5

[0114] In one embodiment, a specific implementation method based on the above mass concentration calculation method is also provided.

[0115] Obtain an aerosol sample and pass it into the SPMS device for analysis for one minute. The spectrum is obtained by the time-of-flight mass spectrometer and compared with the database. The particle composition is obtained as silicate, organic carbon, rust, polycyclic aromatic hydrocarbons, biomass, and the number concentration ratio of each substance. Then, the density of the above substances is obtained by querying 2400kg / m 3 , 800kg / m 3 , 1200kg / m 3 , 5000kg / m3 、1180kg / m 3 . Aerodynamic diameter d a The conversion coefficient k to geometric diameter d is 0.6, and the instrument injection flow rate is 0.6L / min. The specific data are shown in the following table.

[0116]

[0117]

[0118] Among them, in the present application, the average diameter refers to the average diameter of a certain particle size range, which is obtained by taking the average of the maximum and minimum values ​​within the particle size range; the sizing efficiency is calculated using the method in Example 1 or Example 2; the silicate content ratio refers to the content ratio of silicate within the particle size range. For example, if you want to perform source analysis on silicate particles, the silicate particles are the single-category particles referred to in Example 1. Taking the data in the first row as an example, within the particle size range of 0.15μm to 0.25μm, the silicate content ratio is 0.212, that is, within the particle size range of 0.15μm to 0.25μm, the number of sizing particles of the second kinetic particle size of silicate is 0.212*6914≈1466. In this embodiment, regardless of whether the statistical efficiency is calculated by the method of Example 1 or Example 2, the subsequent calculation method is the same, and the number of particles of the first kinetic particle size measured by silicate should be 1466 / 0.51=2874. In this particle size segment, the number concentration N of silicate should be In this application, the particles are approximately regarded as spheres, and the mass concentration of silicates can be calculated based on the number concentration and density of silicates. Where d is the average diameter of the particle size range, 0.2 μm, and the density of silicate is ρ = 2.4*10 6 g / m 3 , it can be deduced that the mass concentration of silicate in this particle size range is

[0119] Through the above steps, it can be known that the true number concentration of silicate particles in each particle size segment can be calculated using statistical efficiency, and based on this method, the mass concentration of silicate in each particle size range can be further calculated.

[0120] Embodiment 6

[0121] Further, in addition to the calculation process for calculating mass concentration provided in Example 1, the present application also provides other quantitative calculation processes, specifically including the true number concentration and the true content, specifically including:

[0122] Calculate the true number concentration C corresponding to any substance in all particle size ranges t_Mi ,include:

[0123]

[0124] Among them, N i represents the total number of particles in the mass spectrometry data within the i-th particle size range; a i,j represents the proportion of the jth substance in the i-th particle size range; Q represents the injection flow rate of the instrument, in L / min; η i Represents the statistical efficiency within the i-th particle size range.

[0125] Calculate the true content of each substance α T_Mj ,include:

[0126]

[0127] Among them, a i,j Indicates the proportion of the jth substance in the i-th particle size range; N i represents the total number of particles in the mass spectrum data within the i-th particle size range; η i Represents the statistical efficiency within the i-th particle size range.

[0128] Embodiment 7

[0129] In one embodiment, a computer device is provided. The computer device may be a server, and its internal structure diagram may be as follows: Figure 3 As shown. The computer device includes a processor, a memory, a network interface and a database connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. When the computer program is executed by the processor, an aerosol mass concentration calculation method is implemented.

[0130] Those skilled in the art will understand that Figure 3 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0131] In one embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the following steps are implemented:

[0132] After the aerosol sample is focused into a particle beam using the sampling module, a double-peak diameter measurement signal generated by the sampled particles in the particle beam arriving at the first position of the diameter measurement module is received, wherein the double-peak diameter measurement signal is generated after the sampled particles arriving at the first position are irradiated by the first laser unit in the diameter measurement module;

[0133] Using the mass spectrometry module to analyze the injected particles to obtain mass spectrometry data;

[0134] Based on the mass spectrometry data, the original source-analyzed distribution of the single-category particles is calculated; and using the bimodal diameter measurement signal, the original source-analyzed distribution is quantitatively corrected to obtain the true source-analyzed distribution of the single-category particles;

[0135] Based on the true source-analyzed distribution, the mass concentration of a single type of particles is calculated.

[0136] In one embodiment, the laser generated by the first laser unit is two parallel laser beams; the receiving of the double-peak diameter measurement signal generated by the sampled particles in the particle beam arriving at the first position of the diameter measurement module specifically includes: respectively receiving two first light signals generated by each of the sampled particles passing through the two parallel laser beams in sequence, and generating a double-peak diameter measurement signal based on the time difference between the two first light signals.

[0137] In one embodiment, the original source resolved distribution of a single category of particles is calculated based on the mass spectrometry data, specifically comprising: determining the particle type of each ionized sampled particle and the number of particles corresponding to each particle type based on the mass spectrometry data; determining the original source resolved distribution of each single category of particles based on the particle type of the sampled particles and the number of particles corresponding to each particle type in the mass spectrometry data; the original source resolved distribution is specifically the number of the single category of particles within each particle size range.

[0138] In one embodiment, the bimodal sizing signal is used to perform quantitative correction on the original source-analyzed distribution to obtain a true source-analyzed distribution of single-category particles, specifically including: calculating the statistical efficiency in each particle size range based on the bimodal sizing signal and the mass spectrometry data; calculating the ratio of the target number of each particle type in the original source-analyzed distribution in each particle size segment to the statistical efficiency corresponding to the particle size segment to obtain the true source-analyzed distribution.

[0139] In one embodiment, the statistical efficiency in each particle size segment is calculated based on the bimodal sizing signal and the mass spectrum data, specifically including: generating a bimodal particle size distribution corresponding to the injected particles based on the time difference between the bimodal sizing signals; generating a mass spectrum particle size distribution based on the particle information in the mass spectrum data and the bimodal sizing distribution; and calculating the statistical efficiency in each particle size segment based on the bimodal sizing distribution and the mass spectrum particle size distribution.

[0140] In one embodiment, the use of the mass spectrometry module to analyze the injected particles to obtain mass spectrometry data specifically includes: calculating the flight speed of the injected particles based on the time difference between the two first light signals and the distance between the two parallel laser beams; calculating the ionization time when the injected particles reach the ionization position based on the flight speed of the injected particles; according to the ionization time, emitting ionization laser to ionize the injected particles to generate ions, measuring the mass-to-charge ratio of the ions, and obtaining the mass spectrometry data of the injected particles.

[0141] In one embodiment, the mass concentration of a single type of particles is calculated based on the real source analysis distribution, specifically comprising: quantitatively analyzing the aerosol sample based on the real source analysis distribution to obtain the real mass concentration ρ corresponding to any substance in all particle size ranges N_Mj , the true mass concentration ρ corresponding to all substances within any particle size range N_di And the total mass concentration of all substances in all particle size ranges ρ N .

[0142] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0143] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0144] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A method for calculating aerosol mass concentration, characterized in that: Applied to a single-particle aerosol mass spectrometer source analysis device, the source analysis device includes: a sampling module, a diameter measurement module and a mass spectrometry module; the mass concentration calculation method specifically includes: After the aerosol sample is focused into a particle beam using the sampling module, a double-peak diameter measurement signal generated by the sampled particles in the particle beam arriving at the first position of the diameter measurement module is received, wherein the double-peak diameter measurement signal is generated after the sampled particles arriving at the first position are irradiated by the first laser unit in the diameter measurement module; Using the mass spectrometry module to analyze the injected particles to obtain mass spectrometry data; Based on the mass spectrometry data, the original source-analyzed distribution of the single-category particles is calculated; and using the bimodal diameter measurement signal, the original source-analyzed distribution is quantitatively corrected to obtain the true source-analyzed distribution of the single-category particles; Based on the true source-analyzed distribution, the mass concentration of a single type of particles is calculated.

2. The method for calculating aerosol mass concentration according to claim 1, characterized in that: The laser light generated by the first laser unit is two parallel laser beams; The receiving of the double-peak diameter measurement signal generated by the sampled particle in the particle beam arriving at the first position of the diameter measurement module specifically includes: Two first light signals generated by each of the sampled particles passing through two parallel laser beams in sequence are received respectively, and a double-peak diameter measurement signal is generated based on the time difference between the two first light signals.

3. The method for calculating aerosol mass concentration according to claim 2, characterized in that: The calculating the original source analysis distribution of a single type of particles based on the mass spectrum data specifically includes: Based on the mass spectrum data, respectively determine the particle type of each ionized sample particle and the number of particles corresponding to each particle type; Based on the particle type of the injected particles and the number of particles corresponding to each particle type in the mass spectrometry data, the original source-analyzed distribution of each single-category particle is determined; the original source-analyzed distribution is specifically the number of the single-category particles within each particle size range.

4. The method for calculating aerosol mass concentration according to claim 3, characterized in that: The method of using the bimodal diameter measurement signal to quantitatively correct the original source-analyzed distribution to obtain a true source-analyzed distribution of single-category particles specifically includes: Calculate the statistical efficiency in each particle size range based on the bimodal sizing signal and the mass spectrum data; The ratio of the target number of each particle type in each particle size segment of the original source analysis distribution to the statistical efficiency corresponding to the particle size segment is calculated to obtain the true source analysis distribution.

5. The method for calculating aerosol mass concentration according to claim 4, characterized in that: The calculating of the statistical efficiency in each particle size range based on the bimodal sizing signal and the mass spectrum data specifically includes: Generating a bimodal particle size distribution corresponding to the injected particles based on a time difference between the bimodal diameter measurement signals; Generate a mass spectral particle size distribution based on the particle information in the mass spectral data and the bimodal size distribution; Based on the bimodal size distribution and mass spectrometry particle size distribution, the statistical efficiency within each particle size range is calculated.

6. The method for calculating aerosol mass concentration according to claim 5, characterized in that: The using the mass spectrometry module to analyze the injected particles to obtain mass spectrometry data specifically includes: Calculating the flight speed of the injected particles based on the time difference between the two first light signals and the distance between the two parallel laser beams; Based on the flight speed of the injected particles, the ionization time when the injected particles reach the ionization position is calculated; According to the ionization time, ionization laser is emitted to ionize the sample particles to generate ions, The mass-to-charge ratio of the ions is measured to obtain mass spectrum data of the injected particles.

7. The method for calculating aerosol mass concentration according to claim 6, characterized in that: The calculating the mass concentration of a single type of particles based on the true source analysis distribution specifically includes: Based on the true source analysis distribution, the aerosol sample is quantitatively analyzed to obtain the true mass concentration ρ corresponding to any substance in all particle size ranges. N_Mj , the true mass concentration ρ corresponding to all substances within any particle size range N_di And the total mass concentration of all substances in all particle size ranges ρ N .

8. An aerosol mass concentration calculation device, characterized in that: The source resolution device specifically comprises: An optical signal receiving module: after the aerosol sample is focused into a particle beam by using the sampling module, the optical signal receiving module receives a double-peak diameter measurement signal generated when the sampled particles in the particle beam arrive at the first position of the diameter measurement module, wherein the double-peak diameter measurement signal is generated after the first laser unit in the diameter measurement module irradiates the sampled particles arriving at the first position; Mass spectrometry analysis module: used to use the mass spectrometry module to analyze the injected particles to obtain mass spectrometry data; Source analysis calculation and correction module: used to calculate the original source analysis distribution of single-category particles based on the mass spectrometry data, and to perform quantitative correction on the original source analysis distribution using the bimodal diameter measurement signal to obtain the true source analysis distribution of single-category particles; Mass concentration calculation module: used to calculate the mass concentration of a single category of particles based on the true source analysis distribution.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for online mass spectrometry data analysis of exhaled gas according to any one of claims 1 to 7 is implemented.

10. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the aerosol mass concentration calculation method according to any one of claims 1 to 7 is implemented.

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