A method for detecting aerosol field distribution inside heated cigarettes

Abstract

A method for detecting the aerosol field distribution inside a heated cigarette, characterized in that: first, a detection device is constructed, including an aerosol particle size spectrometer, an aerosol in-situ sampling unit, a positioning and fixing system, and a smoking machine. The aerosol in-situ sampling unit is composed of a capillary probe, a silicone tube, an electromagnetic valve, a flow limiting orifice plate, and a dilution flow control module. The heating device needs to be slotted and modified, and the heated cigarette is pre-punched. During the detection, the capillary probe is inserted into different positions inside the heated cigarette, and the aerosol is extracted in situ during the smoking process of the heated cigarette. The aerosol particle size spectrometer is used to test the particle number concentration and particle size distribution of the aerosol in real time. After data processing, the aerosol field distribution inside the heated cigarette is obtained.

Description

Technical Field

[0001] The invention belongs to the field of aerosol testing methods, and in particular relates to a method for detecting aerosol field distribution inside a heated cigarette. Background Art

[0002] Heated cigarettes are a new type of tobacco product that releases aerosols by heating tobacco and is inhaled by consumers. Different types of heated cigarettes have different physical and chemical properties of aerosols, which are related to the sensory quality of heated cigarette products. How to control the physical and chemical properties of heated cigarette aerosols through the design of products and formulas to meet the needs of consumers is a challenge faced in the development of heated cigarette products in my country. Unlike traditional cigarettes that form aerosols through combustion, pyrolysis, distillation, condensation, etc., heated cigarettes mainly form aerosols through pyrolysis, distillation, condensation, etc. The aerosol formation process of the two is very different. Research and characterization of the internal aerosol field distribution of heated cigarettes is of great significance for explaining the formation process of heated cigarette aerosols and further regulating heated cigarette aerosols. At present, there are no technical means and methods for detecting the internal aerosol field distribution of heated cigarettes. At present, although there have been relevant research reports on the characterization of heated cigarette aerosols, they all characterize the aerosols at the outlet end of the heated cigarette filter, but are unable to obtain the aerosol information inside the heated cigarette, nor are they able to characterize the dynamic changes of the aerosol during the formation process. Summary of the invention

[0003] The purpose of the present invention is to provide a method for detecting the aerosol field distribution inside heated cigarettes based on the problems existing in the above-mentioned prior art. The method can realize in-situ sampling of the aerosol inside the heated cigarette and the particle number concentration and particle size distribution testing, and obtain the aerosol field distribution of the heated cigarette to reflect the formation process of the heated cigarette aerosol, thereby solving the problem that the aerosol formation process of the heated cigarette cannot be characterized.

[0004] The object of the present invention is achieved through the following solutions:

[0005] A method for detecting the aerosol field distribution inside a heated cigarette is to insert a capillary probe into different positions inside the heated cigarette through a positioning and fixing system and a slotted modification of a heating device, extract aerosol in situ during the smoking process of the heated cigarette, and use an aerosol particle size spectrometer to test the particle number concentration and particle size distribution of the aerosol in real time. After data processing, the aerosol field distribution inside the heated cigarette is obtained.

[0006] The method comprises the following steps:

[0007] (1) Construction of a detection device, including an aerosol particle size spectrometer, an aerosol in-situ sampling unit, a positioning and fixing system, and a smoking machine. The aerosol in-situ sampling unit is composed of a capillary probe, a silicone tube, a solenoid valve, a flow limiting orifice plate, and a dilution flow control module. The positioning and fixing system includes a three-dimensional slide table of the aerosol in-situ sampling unit and a heating device fixing mechanism, and the capillary probe is arranged to intersect the axis of the heating device at right angles.

[0008] (2) Preparation stage, including: slotting and modification of the inner lining tube and outer sleeve of the heating device, pre-punching of heated cigarettes, assembly and fixation of cigarettes on the heating device, connection with the smoking machine, precise insertion of the capillary probe into the pre-punched hole through the three-dimensional slide of the aerosol in-situ sampling unit, gluing and drying the pores, and sealing the slots of the heating device;

[0009] (3) Testing phase, including: starting the heating device, the voltage signal of the solenoid valve delays the triggering of the smoking machine, and the capillary probe is used to sample the aerosol inside the heated cigarette in situ during the smoking process. The aerosol particle number concentration and particle size distribution are tested in real time by the aerosol particle size spectrometer to obtain the aerosol particle number concentration and particle number median particle size data; replacing the heated cigarette and changing the test point position to achieve multiple tests at different positions inside the heated cigarette (different positions include different positions of the cigarette core segment and the filter rod segment);

[0010] (4) Data processing stage, including: based on the measured aerosol particle number concentration and the median particle size, the interpolation method is used to supplement the data at different positions, obtain the data at each position inside the heated cigarette, and construct the aerosol field distribution of the heated cigarette, including the aerosol particle number concentration field distribution and the aerosol particle number median particle size field distribution.

[0011] In the present invention, the aerosol particle size spectrometer performs real-time testing on the aerosol introduced through the inlet pipeline, and the response time is less than 0.5 s, and obtains the particle number concentration, particle size distribution and particle number median particle size data of the aerosol. The particle size test range of the aerosol particle size spectrometer should cover the particle size range of the heated cigarette aerosol, and the particle size spacing within the particle size test range is less than 50nm. Preferably, the particle size test range of the aerosol particle size spectrometer is 1~1000 nm.

[0012] The aerosol in-situ sampling unit is provided with a capillary probe, a silicone tube, and a flow limiting orifice in sequence. The outlet end of the flow limiting orifice intersects with the dilution gas pipeline of the dilution flow control module and is then connected to the inlet pipeline of the aerosol particle size spectrometer. The solenoid valve is provided on the silicone tube for clamping and opening the silicone tube.

[0013] The aerosol in-situ sampling unit controls the dilution gas flow rate through the dilution flow rate control module, thereby achieving accurate control of the capillary probe sampling flow rate.

[0014] The three-dimensional slide table of the aerosol in-situ sampling unit has a distance adjustment function in the three-dimensional directions of XYZ, and the distance adjustment accuracy is 0.01 mm.

[0015] The suction port of the smoking machine is connected to the collector through a pipeline, and is used to suck the heated cigarette inserted into the collector. The suction mode is ISO or HCI mode. The smoking machine suction control system is set to link the smoking machine suction with the opening of the solenoid valve. The solenoid valve voltage signal is set to trigger the smoking mode of the smoking machine, and the trigger time can be set to 0~60 s. The solenoid valve voltage signal is provided by the control system of the aerosol particle size spectrometer, which can realize the opening and closing of the solenoid valve and complete the sampling of the aerosol. Preferably, the solenoid valve voltage signal is a low-level or high-level signal of a square wave. When the solenoid valve voltage rises from a low level to a high level or drops from a high level to a low level, the smoking machine is started to suck after the set trigger time.

[0016] During the preparation stage, the inner lining tube and outer sleeve on one side of the heating device are grooved with a groove width of 1-5 mm (preferably 2 mm); the heated cigarette is pre-drilled at a precise position by the drill bit of the punching device, the hole diameter is 0.3~1.5 mm (preferably 0.5 mm), the minimum depth is 0.05 mm, the maximum depth is the distance from the cigarette paper to the heating core of the heating device, and the depth accuracy is 0.01 mm.

[0017] The detection process of the present invention comprises: inserting a heated cigarette into a heating device, and fixing the heating device by a three-jaw chuck; accurately inserting a capillary probe into a specific position inside the heated cigarette by a displacement slide of a positioning and fixing system, sealing the pores with glue, and sealing the slots of the heating device; then, starting the heating device, and when it is ready to be smoked, an aerosol particle size spectrometer controls the electromagnetic valve of an aerosol in-situ sampling unit to open, and aerosol sampling is performed, and a voltage signal of the electromagnetic valve delays triggering a smoking machine to smoke, that is, completing the in-situ sampling of aerosol inside the heated cigarette during the smoking process of the heated cigarette and the particle number concentration and particle size distribution tests, and completing multiple tests of aerosols at different positions inside the heated cigarette; finally, based on the test results of aerosols at different positions inside the heated cigarette, after data interpolation and supplementation, the aerosol particle number concentration field distribution and the aerosol particle number median particle size field distribution inside the heated cigarette are obtained.

[0018] The advantages of the present invention over the prior art are: by constructing a detection device, the detection of aerosol field distribution at different positions inside the heated cigarette is realized. During the test, the capillary probe is inserted into different positions inside the heated cigarette through the positioning and fixing system, the aerosol is extracted in situ, and the aerosol particle size spectrometer is used to test the aerosol particle number concentration and particle size distribution in real time. After data processing, the aerosol field distribution inside the heated cigarette is obtained, including the aerosol particle number concentration field distribution and the aerosol particle number median particle size field distribution. The invention can realize the in-situ sampling and testing of the aerosol inside the heated cigarette, obtain the aerosol field distribution of the heated cigarette, so as to reflect the formation process of the heated cigarette aerosol, and solve the problem that the formation process of the heated cigarette aerosol cannot be characterized. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 . Schematic diagram of the top view of the structural principle of the device constructed by the method of the present invention.

[0020] Figure 2 . Schematic side view of the capillary probe, silicone tube, solenoid valve, flow limiting orifice plate, sampling unit matrix and three-dimensional slide connection structure of the method of the present invention.

[0021] Figure 3 . Schematic diagram of the positions of the aerosol in-situ sampling unit, the positioning and fixing unit, and the heated cigarette of the present invention.

[0022] Figure 4 . Schematic diagram of the linkage control of the smoking machine suction and the opening of the solenoid valve of the present invention.

[0023] Figure 5 . A test position diagram for detecting the internal aerosol field of a heated cigarette according to the present invention.

[0024] Figure 6 . Schematic diagram of the slotting modification of the heating device in the present invention.

[0025] Figure 7 . Particle number concentration and particle size distribution diagram of in-situ aerosol test at a certain point inside the heated cigarette using the method of the present invention.

[0026] Figure 8 . Results of eight tests on a certain point inside a heated cigarette using the method of the present invention (a, particle number concentration; b, median particle size).

[0027] Fig. 9 . The present invention detects the internal aerosol particle number concentration field distribution diagram of a certain heated cigarette.

[0028] Fig.10 . The present invention detects the median particle size field distribution diagram of the internal aerosol particles of a certain heated cigarette.

[0029] In the figure: 1. Aerosol particle size spectrometer, 11. Inlet, 12. Pipeline, 2. Aerosol in-situ sampling unit, 21. Capillary probe, 22. Silicone tube, 23. Solenoid valve, 24. Flow limiting orifice, 25. Sampling unit matrix, 26. Dilution flow control module, 261. Dilution gas pipeline, 3. Positioning and fixing system, 31. Three-dimensional slide, 311. XY displacement slide, 312. Z displacement slide, 32. Heating device fixing mechanism (i.e. three-jaw chuck), 33. Collector, 34. Positioning bottom plate, 4. Smoking machine, 5. Heated cigarette, 51. Cigarette core segment, 52. Filter rod segment, 6. Heating device, 61. Heating core, 62. Heating core base, 63. Inner lining tube, 64. Outer tube. DETAILED DESCRIPTION

[0030] The present invention is further described below in conjunction with the accompanying drawings (embodiments):

[0031] The method for detecting the aerosol field distribution inside a heated cigarette of the present invention is to insert a capillary probe into different positions inside the heated cigarette through a positioning and fixing system and a slotting modification of a heating device, extract aerosol in situ during the smoking process of the heated cigarette, and use an aerosol particle size spectrometer to test the particle number concentration and particle size distribution of the aerosol in real time. After data processing, the aerosol field distribution inside the heated cigarette is obtained.

[0032] The method comprises the following steps:

[0033] (1) Construction of detection device, such as Figure 1-3 As shown: it includes an aerosol particle size spectrometer 1, an aerosol in-situ sampling unit 2, a positioning and fixing system 3, and a smoking machine 5. The aerosol in-situ sampling unit 2 is composed of a capillary probe 21, a silicone tube 22, a solenoid valve 23, a flow limiting orifice 24, and a dilution flow control module 26. The positioning and fixing system 3 includes an aerosol in-situ sampling unit three-dimensional slide 31 and a heating device fixing mechanism 32, and the capillary probe 21 and the heating device 6 are arranged in a perpendicular intersecting manner.

[0034] (2) Preparation stage, including: slotting and modification of the inner lining tube 63 and the outer sleeve 64 of the heating device, pre-punching of the heated cigarette 5, assembly of the cigarette on the heating device 6 and fixation, connection with the smoking machine 4, precise insertion of the capillary probe 21 into the pre-punched hole through the three-dimensional slide 31 of the aerosol in-situ sampling unit, gluing and drying the pores, and sealing the slots of the heating device;

[0035] (3) Testing phase, including: starting the heating device 6, the voltage signal of the solenoid valve 23 delays triggering the smoking machine 4 to draw, so that the capillary probe 21 can sample the aerosol inside the heated cigarette 5 in situ during the drawing process, and the aerosol particle number concentration and particle size distribution are tested in real time by the aerosol particle size spectrometer 1 to obtain the aerosol particle number concentration and particle number median particle size data; replacing the heated cigarette and changing the test point position to achieve multiple tests at different positions inside the heated cigarette (different positions include different positions of the cigarette core segment and the filter rod segment);

[0036] (4) Data processing stage, including: based on the measured aerosol particle number concentration and the median particle size, the interpolation method is used to supplement the data at different positions, obtain the data at each position inside the heated cigarette, and construct the aerosol field distribution of the heated cigarette, including the aerosol particle number concentration field distribution and the aerosol particle number median particle size field distribution.

[0037] A more specific description is as follows:

[0038] The aerosol particle size spectrometer 1 can perform real-time testing on the aerosol introduced through the inlet 11 pipeline 12, with a test response time of less than 0.5 s, and obtain the particle number concentration, particle size distribution and particle number median particle size data of the aerosol. The particle size test range of the aerosol particle size spectrometer 1 should cover the particle size range of the heated cigarette 5 aerosol, and the particle size spacing within the particle size test range is less than 50 nm. The particle size test range of the aerosol particle size spectrometer 1 is 5~1000 nm.

[0039] The aerosol in-situ sampling unit 2 is provided with a capillary probe 21, a silicone tube 22, and a flow limiting orifice 24 in sequence. The outlet end of the flow limiting orifice 24 intersects with the air flow pipeline of the dilution flow control module 26 and is then connected to the inlet 11 pipeline 12 of the aerosol particle size spectrometer 1. The solenoid valve 23 is provided on the silicone tube 22 for clamping and opening the silicone tube 22.

[0040] The capillary probe 21 is a metal capillary, one end of which is used for aerosol sampling, and the other end is sealed and connected to the silicone tube 22. The inner diameter of the capillary probe 21 is 0.2 mm, and the outer diameter is 0.4 mm.

[0041] The silicone tube 22 is placed at the clamping rod of the electromagnetic valve 23 . The inner diameter of the silicone tube 22 is 1.5 mm. One side of the silicone tube 22 is connected to the capillary probe 21 , and the other side is connected to the flow limiting orifice 24 .

[0042] The flow limiting orifice plate 24 is a metal flat plate with a through hole in the middle, and the diameter of the through hole is 0.5 mm.

[0043] The dilution flow control module 26 is provided with a dilution gas introduction gas path. The control module can realize the introduction of a specific flow of dilution gas. By controlling the dilution gas flow, the accurate control of the sampling flow of the capillary probe 21 can be realized. The sampling time of the capillary probe 21 is set to the duration of the suction. The sampling flow of the capillary probe 21 is set to 5 ml, and the sampling time is the middle section of the suction duration, and the sampling time is 1 s.

[0044] The positioning and fixing system 3 includes an XY displacement slide 311 , a Z displacement slide 312 , a heating device fixing mechanism 32 (ie, a three-jaw chuck), a catcher 33 , and a positioning base plate 34 .

[0045] The aerosol particle size spectrometer 1 is connected to the aerosol in-situ sampling unit 2 through the inlet 11 pipeline 12. The aerosol in-situ sampling unit 2 is fixedly connected to the XY displacement slide 311 of the positioning and fixing system 3. The XY displacement slide 311 is fixed to the Z displacement slide 312. The heating device 6 is fixed by the three-jaw chuck 32, and the heated cigarette 5 is connected to the collector 33. The Z displacement slide 312, the three-jaw chuck 32 and the collector 33 are fixed on the positioning base plate 34. The axis of the capillary probe 21 of the aerosol in-situ sampling unit 2 is arranged in a perpendicular direction to the axis of the heating device 6. The capillary probe 21 can be adjusted to a horizontal position with the axis of the heated cigarette 5 through the Z displacement slide 312, and the capillary probe 21 can be accurately inserted into different positions inside the heated cigarette 5 through the XY displacement slide 311 (see Figure 5 ).

[0046] The air suction port of the smoking machine 4 is connected to the collector 33 through a pipeline, and is used to suck the heated cigarette 5 inserted into the collector 33. The suction mode is ISO or HCI mode. The suction control system of the smoking machine 4 is set to link the suction of the smoking machine 4 with the opening of the solenoid valve 23. The voltage signal of the solenoid valve 23 is set to trigger the suction mode of the smoking machine 4, and the trigger time can be set to 29.5 s.

[0047] The voltage signal of the electromagnetic valve 23 is a square wave high level signal. When the voltage of the electromagnetic valve 23 drops from a high level to a low level, the smoking machine 4 is started to draw after a set triggering time.

[0048] See also Figure 6 : The inner lining tube 63 and the outer sleeve 64 of the heating device 6 are grooved on one side, the groove width is 2 mm, and the depth is from the outermost side to the cigarette side; the heated cigarette 5 is pre-drilled at a precise position by the drill bit of the punching device, the hole diameter is 0.5 mm, the minimum depth is 0.05 mm, the maximum depth is the distance from the cigarette paper to the heating core 61 of the heating device 6, and the depth accuracy is 0.01 mm.

[0049] Embodiment 1:

[0050] A method for detecting the aerosol field distribution inside a heated cigarette, wherein the smoking control system of the smoking machine 4 is configured to link the smoking of the smoking machine 4 with the opening of the electromagnetic valve 23, such as Figure 4 As shown, the opening interval of the solenoid valve 23 is set to 30 s, that is, the solenoid valve 23 is opened every 30 s, and the opening time is 1 s (i.e., the sampling time). When the solenoid valve 23 is opened for the first time, the trigger signal of the solenoid valve 23 is delayed by 29.5 s to trigger the smoking machine 4 to take the first puff. Then, the smoking machine 4 takes the puff 0.5 s earlier than the second opening of the solenoid valve 23, thereby realizing the second opening of the solenoid valve 23 and the sampling of the capillary probe 21, and collecting the aerosol during the first puff of the heated cigarette 5. Similarly, when the solenoid valve 23 is opened for the second time, the delay of 29.5 triggers the second puff, and the third opening of the solenoid valve 23 realizes the aerosol sampling of the second puff.

[0051] The specific process is as follows: first, the inner lining tube 63 and the bracket 64 of the heating device 6 are slotted and modified, the heated cigarette 5 is pre-punched, and the heated cigarette 5 is inserted into the heating device 6, and the heating device 6 is fixed by the three-claw chuck 32; the capillary probe 21 is accurately inserted into a specific position inside the heated cigarette 5 through the XY displacement slide 311 and the Z displacement slide 312 of the positioning and fixing system 3, the pores are sealed with glue, and the slots of the inner lining tube 63 and the bracket 64 of the heating device 6 are sealed; then, the heating device 6 is started, and when it is ready to be smoked, the aerosol particle size spectrometer 1 controls the electromagnetic valve 23 of the aerosol in-situ sampling unit 2 to open, and aerosol sampling is performed, and the voltage signal of the electromagnetic valve 23 delays the smoking machine 4 to smoke the heated cigarette 5 in ISO or HCI mode, that is, the in-situ sampling of the aerosol inside the heated cigarette 5 during the smoking process of the heated cigarette 5 and the particle number concentration and particle size distribution test are completed, and different positions inside the heated cigarette 5 are completed (see Figure 5 ) multiple tests of aerosol, that is, multiple tests are performed on aerosols at different positions of the cigarette core segment 51 and the filter rod segment 52; finally, based on the test results of aerosols at different positions inside the heated cigarette 5, after data interpolation and supplementation, the aerosol particle number concentration field distribution and the aerosol particle number median particle size field distribution inside the heated cigarette 5 are obtained.

[0052] Embodiment 2:

[0053] The method of the present invention is used to detect the aerosol field distribution inside a certain heated cigarette. Figure 5 The in-situ sampling positions of the heated cigarette 5 aerosol are shown, including different positions of the cigarette core section 51 and the filter rod section 52. The sampling flow rate of the capillary probe is set to 5 ml. The smoking machine uses the HCI suction mode to smoke the heated cigarette, and the particle number concentration and particle size distribution of the aerosol sampled at different positions are measured (see Figure 7), the average particle number concentration and the median particle size were calculated. Before the test, a certain position of the heated cigarette was tested 8 times in succession to examine the stability of the test method. Figure 8 As shown in the figure, the 8 test results of particle number concentration are relatively consistent, with an RSD of 4.2%; the 8 test results of particle number median particle size are also relatively consistent, with an RSD of 3.1%, indicating that this method has good test repeatability. In the actual test, each test point of the heated cigarette was measured in parallel 5 times, and the average result was taken. The particle number concentration at each position is shown in Table 1, and the particle number median particle size at each position is shown in Table 2. Based on the measured position data, the cubic spline interpolation method is used for data interpolation processing to obtain the data at each position inside the heated cigarette, and the aerosol particle number concentration and aerosol particle number median particle size field distribution map inside the heated cigarette can be obtained.

[0054] The core section 51 of the heated cigarette 5 is a key position for aerosol formation and needs to be investigated in detail. The aerosol particle number concentration field distribution of the core section 51 of the heated cigarette 5 is plotted, as shown in FIG. Fig. 9 As shown. The aerosol particle number concentration of the heated cigarette 5 near the heating core base 62 is close to 0. In the lateral direction, the aerosol particle number concentration gradually increases and increases to the highest value in the upper half of the heating core 61. At the same time, the area with higher particle number concentration values ​​also shows an increasing trend in the radial direction. In the radial direction, there is a higher aerosol particle number concentration near the heating core 61, and it decreases in the radial direction.

[0055] The aerosol particle number median particle size field distribution of the core segment 51 of the heated cigarette 5 is plotted, as shown in FIG. Fig.10 As shown in the figure. The aerosol particle number median size field distribution shows a similar result to the particle number concentration field distribution. In the lateral direction, the aerosol particle size gradually increases, and the aerosol particle size near the middle and upper part of the heating core is larger; in the radial direction, the closer to the heating core, the larger the aerosol particle size.

[0056] Table 1. Aerosol particle number concentrations at different positions during the smoking process of a heated cigarette (×10 9 Pieces / cm 3 )

[0057] Location 1 2 3 4 5 6 7 8 9 outside - 2.5 - - - - - - middle 2.4 3.0 - - 1.3 1.3 - - Inside 1.8 3.3 3.7 - - - - - - Heating core - - - 2.5 2.3 1.9 1.7 0.65 0.16 Inside 1.8 3.3 3.7 - - - - - - middle - 2.4 3.0 - - 1.3 1.3 - - outside - 2.5 - - - - - -

[0058] Table 2. Median particle size of aerosol particles at different positions during the smoking process of a certain heated cigarette (nm)

[0059] Location 1 2 3 4 5 6 7 8 9 outside - - 18.2 - - - - - - middle - 17.8 26.8 - - 35.0 35.1 - - Inside 18.1 25.5 32.2 - - - - - - Heating core - - - 34.5 35.0 36.5 35.4 36.3 36.8 Inside 18.1 25.5 32.2 - - - - - - middle - 17.8 26.8 - - 35.0 35.1 - - outside - - 18.2 - - - - - -

Claims

1. A method for detecting the aerosol field distribution inside a heated cigarette, characterized in that: Through positioning and fixing the system and slotting the heating device, the capillary probe is inserted into different positions inside the heated cigarette, and the aerosol is extracted in situ during the smoking process of the heated cigarette. The aerosol particle size spectrometer is used to test the particle number concentration and particle size distribution of the aerosol in real time. After data processing, the aerosol field distribution inside the heated cigarette is obtained; The method comprises the following steps: (1) Construction of a detection device, including an aerosol particle size spectrometer, an aerosol in-situ sampling unit, a positioning and fixing system, and a smoking machine. The aerosol in-situ sampling unit is provided with a capillary probe, a silicone tube, and a flow limiting orifice plate in sequence. The outlet end of the flow limiting orifice plate intersects with the dilution gas pipeline of the dilution flow control module and is then connected to the inlet pipeline of the aerosol particle size spectrometer. A solenoid valve is provided on the silicone tube for clamping and opening the silicone tube. The aerosol in-situ sampling unit controls the dilution gas flow rate through the dilution flow control module to achieve precise control of the sampling flow rate of the capillary probe. The positioning and fixing system includes a three-dimensional slide table of the aerosol in-situ sampling unit and a heating device fixing mechanism, and the capillary probe is arranged to intersect the axis of the heating device at right angles. (2) Preparation stage, including: slotting and modification of the inner lining tube and outer sleeve of the heating device, pre-punching of heated cigarettes, assembly of cigarettes on the heating device and fixing, connection with the smoking machine, precise insertion of the capillary probe into the pre-punched hole through the three-dimensional slide of the aerosol in-situ sampling unit, gluing and sealing the pores, blowing and drying, and sealing the slots of the heating device; the suction port of the smoking machine is connected to the collector through a pipeline, which is used to suck the heated cigarettes inserted into the collector, the suction mode is ISO or HCI mode, the smoking control system of the smoking machine is set to the linkage between the smoking of the smoking machine and the opening of the solenoid valve, and the solenoid valve voltage signal is set to trigger the smoking mode of the smoking machine, and the trigger time can be set to 0~60 s; (3) Testing phase, including: starting the heating device, the voltage signal of the solenoid valve delays triggering the smoking machine to draw, so that the capillary probe can sample the aerosol inside the heated cigarette in situ during the drawing process, and the aerosol particle number concentration and particle size distribution are tested in real time by the aerosol particle size spectrometer to obtain the aerosol particle number concentration and particle number median particle size data; replacing the heated cigarette and changing the test point position to achieve multiple tests at different positions inside the heated cigarette; (4) Data processing stage, including: based on the measured aerosol particle number concentration and the median particle size, the interpolation method is used to supplement the data at different positions, obtain the data at each position inside the heated cigarette, and construct the aerosol field distribution of the heated cigarette, including the aerosol particle number concentration field distribution and the aerosol particle number median particle size field distribution.

2. The method for detecting the aerosol field distribution inside a heated cigarette according to claim 1, characterized in that: The aerosol particle size spectrometer performs real-time testing on the aerosol introduced through the inlet pipeline, with a response time of less than 0.5 s, and obtains the particle number concentration, particle size distribution and particle number median particle size data of the aerosol.

3. The method for detecting the aerosol field distribution inside a heated cigarette according to claim 1, characterized in that: The three-dimensional slide table of the aerosol in-situ sampling unit has a distance adjustment function in the three-dimensional directions of XYZ, and the distance adjustment accuracy is 0.01mm.

4. The method for detecting the aerosol field distribution inside a heated cigarette according to claim 1, characterized in that: During the preparation stage, the inner lining tube and outer sleeve on one side of the heating device are grooved with a groove width of 1-5 mm; the heated cigarette is pre-drilled at a precise position by the drill bit of the punching device, with a hole diameter of 0.3~1.5 mm, a minimum depth of 0.05 mm, and a maximum depth of the distance from the cigarette paper to the heating core of the heating device, with a depth accuracy of 0.01 mm.

5. The method for detecting the aerosol field distribution inside a heated cigarette according to claim 1, characterized in that: The different positions inside the heated cigarette include different positions of the cigarette core segment and the filter rod segment.

6. The method for detecting the aerosol field distribution inside a heated cigarette according to claim 1, characterized in that: The detection process includes: inserting the heated cigarette into the heating device, and the heating device is fixed by a three-jaw chuck; the capillary probe is accurately inserted into a specific position inside the heated cigarette through the displacement slide of the positioning and fixing system, and the pores are sealed with glue, and the slots of the heating device are sealed; then, the heating device is started, and when it is ready to be smoked, the aerosol particle size spectrometer controls the solenoid valve of the aerosol in-situ sampling unit to open, and aerosol sampling is performed, and the voltage signal of the solenoid valve delays to trigger the smoking machine to smoke, that is, the in-situ sampling and particle number concentration and particle size distribution tests of the aerosol inside the heated cigarette during the smoking process of the heated cigarette are completed, and multiple tests of the aerosol at different positions inside the heated cigarette are completed; finally, based on the test results of the aerosol at different positions inside the heated cigarette, the aerosol particle number concentration field distribution and the aerosol particle number median particle size field distribution inside the heated cigarette are obtained after data interpolation and supplementation.

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