An in-situ method for detecting particle spectrum concentration in a low pressure chamber

Abstract

The application provides a kind of for low pressure cabin particle spectrum concentration in-situ detection method, comprising the following steps: S1, builds low pressure cabin particle spectrum concentration in-situ detection system;S2, utilizes data processing and control system to initialize setting low pressure cabin particle spectrum concentration in-situ detection system;S3, by the data processing and control system control vacuum electromagnetic valve open, MEMS anemometer measures wind speed data, when wind speed is stable, automatic control module will wind speed feedback loop setting be closed loop state, wind speed is stable to set value v set ;S4, particle spectrum concentration data detection: data processing and control system read the particle spectrum measured by on-board particle spectrum probe instrument, and calculate to obtain particle spectrum concentration data.The application provides a kind of for low pressure cabin particle spectrum concentration in-situ detection method, can eliminate the error caused by particle measurement outside the cabin.

Description

Technical Field

[0001] This invention relates to the technical field of airborne particle spectrum probe instruments used in low-pressure chambers, specifically to an in-situ detection method for particle spectrum concentration in low-pressure chambers. Background Technology

[0002] A particle spectrum refers to the distribution of the number of particles per unit volume as a function of particle size. The concentration unit of a particle spectrum is usually expressed as particles per centimeter (cm³). 3 Particle density refers to the number of particles contained in a unit volume. It is widely used in meteorology, such as in cloud physics experiments and artificial precipitation research.

[0003] Airborne particle spectrum probes are in-situ particle spectrum detection instruments used on aircraft. They are key equipment for directly observing the particle spectrum and concentration of particles in high-altitude clouds, playing a vital role in remote sensing inversion verification, numerical simulation of cloud and fog processes, cloud physics process detection, weather modification, and air pollution monitoring. Airborne particle spectrum probes can adapt to the temperature and pressure environments of 0–15 km in the high atmosphere and are suitable for harsh conditions such as low temperature and low pressure environments. Therefore, they can be used for detecting simulated cloud and fog environments in low-pressure chambers.

[0004] In existing technologies, the application of airborne particle spectroscopy probes in low-pressure chambers generally involves placing the probes outside the chamber, a method known as non-in-situ measurement. This method cannot achieve in-situ particle measurement. For non-in-situ measurement, as particles move from the low-pressure chamber to the detection area of ​​the airborne probe, they undergo collisions, coalescence, and growth. Furthermore, as the outside temperature increases, the properties of the particles change. Therefore, non-in-situ measurement cannot fully reflect the true distribution of particles within the chamber. Summary of the Invention

[0005] The present invention aims to overcome the problem that in-situ particle measurement is not possible in the prior art, and provides an in-situ detection method for particle spectrum concentration in low-pressure chambers, which can eliminate the errors caused by measuring particles outside the chamber.

[0006] This invention provides an in-situ detection method for particle spectral concentration in a low-pressure chamber, comprising the following steps:

[0007] S1. System Setup: Set up an in-situ particle spectrum concentration detection system for a low-pressure chamber.

[0008] S2. Initialization Settings: The data processing and control system is used to initialize the in-situ particle concentration detection system in the low-pressure chamber, setting the wind speed v in the particle measurement coupling duct. setThe vacuum solenoid valve is shut off, and the automatic control module sets the wind speed feedback loop to open loop. A cloud and fog experiment is conducted in the low-pressure chamber, and depressurization begins.

[0009] S3. Wind Speed ​​Measurement: The data processing and control system controls the opening of the vacuum solenoid valve, and the air extraction device in the low-pressure chamber begins to extract air from inside the chamber to the outside, providing airflow to the probe detection area. The MEMS anemometer measures the wind speed data. Once the wind speed stabilizes, the automatic control module sets the wind speed feedback loop to a closed-loop state, and the wind speed stabilizes at the set value v. set ;

[0010] S4. Particle Spectrum Concentration Data Detection: The data processing and control system communicates with the airborne particle spectrum probe instrument, reads the particle spectrum measured by the airborne particle spectrum probe instrument, and calculates the particle spectrum concentration data based on the particle spectrum. The calculation method is as follows:

[0011]

[0012] Where C p (d) represents the particle spectral concentration, A represents the detection area of ​​the airborne particle spectral probe instrument, and C represents the particle spectral concentration. pt (d) represents the number of particles whose equivalent diameter falls within the interval [d, d + Δd) during the integration time t, where Δd is the particle spectral width of each interval, and v w To detect the wind speed in the area.

[0013] The in-situ detection method for particle spectrum concentration in low-pressure chambers according to the present invention, in a preferred embodiment, includes the following steps in step S3: The wind speed feedback loop controls the particle measurement coupling duct.

[0014] S31. Determine the initial volumetric flow rate control value Φ out0 Based on the set value v of the wind speed in the particle measurement coupling duct. set The initial volumetric flow rate control value of the mass flow controller is determined as follows:

[0015]

[0016] Where Φ out P is the volumetric flow rate control value. in The pressure at the probe's dedicated gas path fixture is R, the radius of the first gas hose is μ, the dynamic viscosity of air is L, and the length of gas transmission is v. in The airflow velocity at the horn-shaped air intake;

[0017] S32, PID Correction: Measure the wind speed v within the particle measurement coupled duct using a MEMS anemometer. mea Compare it with the wind speed setpoint v set The difference Δv = v mea-v set As the input to the PID controller, the output of the PID controller is passed through the proportional coefficient K. Φ The correction ΔΦ for the volumetric flow control value obtained after amplification out Using Φ out0 +ΔΦ out Update Φ out The volumetric flow rate of the mass flow controller is controlled within Φ. out ;

[0018] S33. Wind speed stabilization: Repeat step S32 until Δv = 0. The wind speed in the particle-measured coupled duct has reached the set wind speed value v. set .

[0019] The present invention discloses an in-situ detection method for particle spectrum concentration in a low-pressure chamber. In a preferred embodiment, the in-situ detection system for particle spectrum concentration in a low-pressure chamber includes an airborne particle spectrum probe instrument disposed within the low-pressure chamber; an airborne particle spectrum probe arm disposed at one end of the airborne particle spectrum probe instrument; a probe detection area connected to the other end of the airborne particle spectrum probe arm; a dedicated gas path fixture for the probe disposed within the probe detection area; a low-pressure chamber extraction device connected to the dedicated gas path fixture; a MEMS anemometer disposed on the dedicated gas path fixture; and a data processing and control system connected to the airborne particle spectrum probe instrument and the low-pressure chamber extraction device. The MEMS anemometer is small in size and placed behind the measurement area, i.e., behind the air duct, minimizing its impact on the probe measurement area.

[0020] The present invention discloses an in-situ detection method for particle spectrum concentration in a low-pressure chamber. In a preferred embodiment, the low-pressure chamber evacuation device includes a flange blind plate connected to the low-pressure chamber wall, a first metal gas pipe passing through the flange blind plate, a first gas hose with both ends connected to one end of the first metal gas pipe and a probe-specific gas path fixture, a vacuum solenoid valve mounted on the first metal gas pipe, a second metal gas pipe with one end connected to the other end of the first metal gas pipe, a mass flow controller mounted on the second metal gas pipe, and a vacuum pump connected to the other end of the second metal gas pipe. A flange hole is provided on the low-pressure chamber wall, and the flange blind plate is connected to the flange hole. The first gas hose is connected to the probe-specific gas path fixture via a first compression fitting, the first gas hose is connected to the first metal gas pipe via a second compression fitting, the first metal gas pipe is connected to the second metal gas pipe via a third compression fitting, and the second metal gas pipe is connected to the vacuum pump via a fourth compression fitting. The first, second, third, and fourth ferrule fittings are corrosion-resistant. The first and second metal gas pipes and the flange blind plate are made of 316L stainless steel. The flange blind plate is drilled with a hole of the outer diameter of the first metal gas pipe. The first metal gas pipe passes through the flange blind plate and extends out at both ends. The first metal gas pipe is welded to the flange blind plate on the outside of the compartment. The first and second metal gas pipes are connected by threads and sealing O-rings.

[0021] The in-situ detection method for particle spectrum concentration in a low-pressure chamber, as described in this invention, preferably includes a horn-shaped air inlet on the probe-specific gas path fixture facing the airborne particle spectrum probe instrument.

[0022] The in-situ detection method for particle spectrum concentration in a low-pressure chamber, as described in this invention, preferably includes a probe laser window and a probe detection window on a dedicated gas path fixture for the probe.

[0023] The in-situ detection method for particle spectrum concentration in a low-pressure chamber, as described in this invention, preferably includes a vacuum waterproof connector on the airborne particle spectrum probe instrument. The vacuum waterproof connector is connected to the data processing and control system via a communication power cable.

[0024] The present invention provides an in-situ detection method for particle spectrum concentration in a low-pressure chamber. In a preferred embodiment, a vacuum penetration connector is provided on the wall of the low-pressure chamber, and a communication power supply cable passes through the vacuum penetration connector.

[0025] The present invention provides an in-situ detection method for particle spectrum concentration in a low-pressure chamber. In a preferred embodiment, the data processing and control system is used for data acquisition, processing, and mass flow controller control of the vacuum solenoid valve, including:

[0026] Data processing module: used to acquire particle spectrum concentration data measured by airborne particle spectrum probe instrument, wind speed data measured by MEMS anemometer, and flow rate data measured by mass flow controller; calculate particle spectrum concentration by combining wind speed data and particle spectrum data from airborne particle spectrum probe instrument; and acquire flow rate data measured by mass flow controller according to the communication protocol of mass flow controller.

[0027] Automatic control module: used to control the flow rate of the mass flow controller and to switch the vacuum solenoid valve on and off.

[0028] The present invention provides an in-situ detection method for particle spectrum concentration in a low-pressure chamber. In a preferred embodiment, a cylindrical particle measurement coupling air duct is formed within a dedicated gas path fixture for the probe, and the detection position of the airborne particle spectrum probe instrument is located at the center of the particle measurement coupling air duct.

[0029] The advantages of this invention compared to existing technologies are: by placing the airborne particle spectrum probe inside the cabin to measure the in-situ particle spectrum concentration, the problem of particle property changes in non-in-situ measurement methods is solved; by using a vacuum pump in conjunction with a mass flow controller for air extraction and designing an automatic control module, accurate wind speed control and wind speed data are provided, thereby improving the accuracy of airborne particle spectrum concentration data. Attached Figure Description

[0030] Figure 1 This is a flowchart of an in-situ detection method for particle spectral concentration in a low-pressure chamber.

[0031] Figure 2 A flowchart of an in-situ detection method for particle spectrum concentration in low-pressure chambers, using a wind speed feedback loop control particle measurement coupled air duct.

[0032] Figure 3 This is a diagram of the composition of an in-situ detection system for particle spectral concentration in a low-pressure chamber, which is a method for in-situ detection of particle spectral concentration in a low-pressure chamber.

[0033] Figure 4 This is a dynamic structure diagram of the feedback loop for accurately controlling the wind speed in the particle measurement coupling duct of an in-situ detection method for particle spectrum concentration in low-pressure chambers.

[0034] Figure Labels

[0035] 1. Airborne particle spectroscopy probe instrument; 2. Low-pressure chamber wall; 3. Airborne particle spectroscopy probe arm; 4. Communication power cable; 5. Horn-shaped air inlet; 6. Probe detection area; 7. First ferrule connector; 8. Probe-specific gas path tooling; 9. First gas hose; 10. Second ferrule connector; 11. Low-pressure chamber; 12. First metal gas tube; 13. Flange hole; 14. Flange blind plate; 15. Vacuum solenoid valve; 16. Vacuum penetration connector; 17. Second gas hose; 18. Third ferrule connector; 19. Data processing and control system; 20. Mass flow controller; 21. Fourth ferrule connector; 22. Vacuum pump; 23. Probe laser window; 24. Probe detection window; 25. Vacuum waterproof air-to-air connector; 26. MEMS anemometer; 27. Second metal gas tube. Detailed Implementation

[0036] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0037] Example 1

[0038] like Figure 1 As shown, an in-situ detection method for particle spectral concentration in a low-pressure chamber includes the following steps:

[0039] S1. System Setup: Set up an in-situ particle spectrum concentration detection system for a low-pressure chamber.

[0040] S2. Initialization Settings: The data processing and control system 19 is used to initialize the in-situ particle spectrum concentration detection system in the low-pressure chamber, setting the wind speed v in the particle measurement coupling duct. setThe vacuum solenoid valve 15 is shut off, the automatic control module sets the wind speed feedback loop to open loop, and a cloud and fog experiment is conducted in the low-pressure chamber 11 to begin depressurization.

[0041] S3. Wind Speed ​​Measurement: The data processing and control system 19 controls the vacuum solenoid valve 15 to open, and the air extraction device in the low-pressure chamber 11 begins to extract air from inside the chamber to the outside, providing airflow for the probe detection area 6. The MEMS anemometer measures the wind speed data. When the wind speed stabilizes, the automatic control module sets the wind speed feedback loop to a closed-loop state, and the wind speed stabilizes to the set value v. set ;like Figure 2 As shown, the wind speed feedback loop control particle measurement coupled duct includes the following steps:

[0042] S31. Determine the initial volumetric flow rate control value Φ out0 Based on the set value v of the wind speed in the particle measurement coupling duct. set The initial volumetric flow control value of the mass flow controller 20 is determined as follows:

[0043]

[0044] Where Φ out P is the volumetric flow rate control value. in The pressure at the probe's dedicated gas path fixture is R, the radius of the first gas hose 9 is μ, the dynamic viscosity of air is L, and the length of gas transmission is v. in The airflow velocity at the horn-shaped air inlet 5;

[0045] S32, PID Correction: The wind speed v in the particle measurement coupled duct is measured using MEMS anemometer 26. mea Compare it with the wind speed setpoint v set The difference Δv = v mea -v set As the input to the PID controller, the output of the PID controller is passed through the proportional coefficient K. Φ The correction ΔΦ for the volumetric flow control value obtained after amplification out Using Φ out0 +ΔΦ out Update Φ out The volumetric flow rate of the mass flow controller 20 is controlled at Φ out ;

[0046] S33. Wind speed stabilization: Repeat step S32 until Δv = 0. The wind speed in the particle-measured coupled duct has reached the set wind speed value v. set ;

[0047] S4. Particle spectrum concentration data detection: The data processing and control system 19 communicates with the airborne particle spectrum probe instrument 1, reads the particle spectrum measured by the airborne particle spectrum probe instrument 1, and calculates the particle spectrum concentration data based on the particle spectrum. The calculation method is as follows:

[0048]

[0049] Where C p (d) represents the particle spectral concentration, A represents the detection area of ​​the airborne particle spectral probe instrument, and C represents the particle spectral concentration. pt (d) represents the number of particles whose equivalent diameter falls within the interval [d, d + Δd) during the integration time t, where Δd is the particle spectral width of each interval, and v w To detect the wind speed in the area.

[0050] like Figure 3 As shown, the in-situ particle spectrum concentration detection system in the low-pressure chamber includes an airborne particle spectrum probe instrument 1 installed in the low-pressure chamber 11, an airborne particle spectrum probe arm 3 installed at one end of the airborne particle spectrum probe instrument 1, a probe detection area 6 connected to the other end of the airborne particle spectrum probe arm 3, a probe-specific gas path fixture 8 installed in the probe detection area 6, a low-pressure chamber exhaust device connected to the probe-specific gas path fixture 8, a MEMS anemometer 26 installed on the probe-specific gas path fixture 8, and a data processing and control system 19 connected to the airborne particle spectrum probe instrument 1 and the low-pressure chamber exhaust device.

[0051] The low-pressure chamber evacuation device includes a flange blind plate 14 connected to the low-pressure chamber wall 2, a first metal gas pipe 12 passing through the flange blind plate 14, a first gas hose 9 with both ends connected to one end of the first metal gas pipe 12 and the probe-specific gas path fixture 8, a vacuum solenoid valve 15 mounted on the first metal gas pipe 12, a second metal gas pipe 27 with one end connected to the other end of the first metal gas pipe 12, a mass flow controller 20 mounted on the second metal gas pipe 27, and a vacuum pump 22 connected to the other end of the second metal gas pipe 27; a flange hole 13 is provided on the low-pressure chamber wall 2, and the flange blind plate 14 is connected to the flange hole 13; the first gas hose 9 is connected to the probe-specific gas path fixture 8 through a first compression fitting 7, the first gas hose 9 is connected to the first metal gas pipe 12 through a second compression fitting 10, the first metal gas pipe 12 is connected to the second metal gas pipe 12 through a third compression fitting 18, and the second metal gas pipe 12 is connected to the vacuum pump 22 through a fourth compression fitting 21. The first ferrule connector 7, the second ferrule connector 10, the third ferrule connector 18, and the fourth ferrule connector 21 are made of corrosion-resistant material. The first metal gas pipe 12, the second metal gas pipe 27, and the flange blind plate 14 are made of 316L stainless steel. The flange blind plate 14 is drilled with a hole of the outer diameter of the first metal gas pipe 12. The first metal gas pipe 12 passes through the flange blind plate 14 and extends out at both ends. The first metal gas pipe 12 and the flange blind plate 14 are welded to the outside of the compartment. The first metal gas pipe 12 and the second metal gas pipe 27 are connected by threads and sealing O-rings.

[0052] A cylindrical particle measurement coupling air duct is formed inside the probe-specific gas path fixture 8, and the detection position of the airborne particle spectrum probe instrument 1 is located at the center of the particle measurement coupling air duct. A horn-shaped air inlet 5 is provided on the probe-specific gas path fixture 8 facing the airborne particle spectrum probe instrument 1. A probe laser window 23 and a probe detection window 24 are provided on the probe-specific gas path fixture 8. A vacuum waterproof aviation plug 25 is provided on the airborne particle spectrum probe instrument 1. The vacuum waterproof aviation plug 25 is connected to the data processing and control system 19 through the communication power supply cable 4. A vacuum penetration connector 16 is provided on the low-pressure chamber wall 2, and the communication power supply cable 4 passes through the vacuum penetration connector 16.

[0053] The data processing and control system 19 is used for data acquisition, processing, and control of the vacuum solenoid valve 15 and the mass flow controller 20, including:

[0054] Data processing module: used to acquire particle spectrum concentration data measured by airborne particle spectrum probe instrument 1, wind speed data measured by MEMS anemometer 26, and flow rate data measured by mass flow controller 20; calculate particle spectrum concentration by combining wind speed data and particle spectrum data from airborne particle spectrum probe instrument 1; and acquire flow rate data measured by mass flow controller 20 according to the communication protocol of mass flow controller 20.

[0055] Automatic control module: used to control the flow rate of mass flow controller 20 and the switching of vacuum solenoid valve 15; the automatic control module is designed with a feedback loop to control the flow rate of mass flow controller 20 based on the wind speed data measured by MEMS anemometer 26, thereby stabilizing the wind speed in the particle measurement coupling duct; and to communicate with vacuum solenoid valve 15 to control the vacuum solenoid valve 15, thereby controlling the flow of air to stop or start the test.

[0056] Considering that the gas in the low-pressure chamber 11 is a compressible Newtonian gas, the gas transmission process in the pumping device is approximately isothermal, and the gas flow velocity in the pipe is slow, with no turbulence, then the gas in the pipe satisfies the Poiseuille equation for an ideal isothermal gas, as shown in the following expression:

[0057]

[0058] Where, Φ out v is the gas volumetric flow rate measured by the mass flow controller 20. out The gas flow velocity at the mass flow controller 20 terminal, R is the radius of the first gas hose, μ is the dynamic viscosity of air, and P... in The air pressure at point 8 of the probe's dedicated air circuit fixture, P out The pressure at the 20th terminal of the mass flow controller is L, and the length of the gas transmission is L.

[0059] Using the ideal gas law for an isothermal process, the following relationship holds:

[0060] P in V in =P out V out

[0061] According to the definition of volumetric flow rate, the following relationship holds:

[0062]

[0063] The airflow velocity v at the horn-shaped air inlet 5 can be obtained. in The gas volumetric flow rate Φ measured by the mass flow controller 20 out The following relationships exist:

[0064]

[0065] A feedback loop was then designed to control the wind speed within the particle measurement coupling duct.

[0066] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An in-situ detection method for particle spectral concentration in a low-pressure chamber, characterized in that: Includes the following steps: S1. System Setup: Set up an in-situ particle spectrum concentration detection system for a low-pressure chamber. The low-pressure chamber particle spectrum concentration in-situ detection system includes an airborne particle spectrum probe instrument (1) installed in the low-pressure chamber (11), an airborne particle spectrum probe arm (3) installed at one end of the airborne particle spectrum probe instrument (1), a probe detection area (6) installed at the other end of the airborne particle spectrum probe arm (3) and connected thereto, a probe-specific gas path fixture (8) installed in the probe detection area (6), a low-pressure chamber exhaust device connected to the probe-specific gas path fixture (8), a MEMS anemometer (26) installed on the probe-specific gas path fixture (8), and a data processing and control system (19) connected to the airborne particle spectrum probe instrument (1) and the low-pressure chamber exhaust device; a particle measurement coupling air duct is formed in the probe-specific gas path fixture (8); S2. Initialization settings: The low-pressure chamber particle spectrum concentration in-situ detection system is initialized using the data processing and control system (19), and the wind speed in the particle measurement coupling duct is set. Turn off the vacuum solenoid valve (15), and the automatic control module sets the wind speed feedback loop to the open loop state. Conduct a cloud and fog experiment in the low-pressure chamber (11) and start depressurization. S3. Wind speed measurement: The data processing and control system (19) controls the vacuum solenoid valve (15) to open, and the air extraction device in the low-pressure chamber (11) starts to extract air from inside the chamber to outside, providing airflow for the probe detection area (6). The MEMS anemometer (26) measures the wind speed data. When the wind speed stabilizes, the automatic control module sets the wind speed feedback loop to a closed loop state. The wind speed stabilizes to the set value. ; S4. Particle spectrum concentration data detection: The data processing and control system (19) communicates with the airborne particle spectrum probe instrument (1), reads the particle spectrum measured by the airborne particle spectrum probe instrument (1), and calculates the particle spectrum concentration data based on the particle spectrum. The calculation method is as follows: ； in For particle spectral concentration, The detection area of ​​the airborne particle spectroscopy probe instrument (1) is... Integration time The equivalent diameter of the inner particle falls within The number of particles in the interval The particle spectral width for each interval, To detect the wind speed in the area.

2. The in-situ detection method for particle spectral concentration in a low-pressure chamber according to claim 1, characterized in that: The wind speed feedback loop control of the particle measurement coupling duct in step S3 includes the following steps: S31. Determine the initial volumetric flow rate control value. Based on the set value of the wind speed in the particle measurement coupling duct. The initial set volumetric flow control value of the mass flow controller (20) is determined as follows: ； in This is the volumetric flow rate control value. The air pressure at the probe's dedicated air circuit fixture. The radius of the first gas hose (9) is... Let be the dynamic viscosity of air. For the length of gas transport, The airflow velocity at the horn-shaped air inlet (5); S32, PID correction: The wind speed measurement value in the particle measurement coupling duct is measured by the MEMS anemometer (26). Combine it with the wind speed setpoint difference As the input to the PID controller, the output of the PID controller is processed by a proportional coefficient. Correction of volumetric flow control value obtained after amplification ,use + renew The volumetric flow rate of the mass flow controller (20) is controlled at... ; S33, Wind speed stabilizes: Repeat step S32 until... The wind speed in the particle measurement coupling duct reaches the set wind speed value. .

3. The in-situ detection method for particle spectral concentration in a low-pressure chamber according to claim 1, characterized in that: The low-pressure chamber extraction device includes a flange blind plate (14) connected to the low-pressure chamber wall (2), a first metal air pipe (12) passing through the flange blind plate (14), a first gas hose (9) with both ends connected to one end of the first metal air pipe (12) and the probe-specific air circuit fixture (8), a vacuum solenoid valve (15) installed on the first metal air pipe (12), a second metal air pipe (27) with one end connected to the other end of the first metal air pipe (12), a mass flow controller (20) installed on the second metal air pipe (27), and a device connected to the other end of the second metal air pipe (27). The vacuum pump (22); a flange hole (13) is provided on the wall (2) of the low-pressure chamber, and the flange blind plate (14) is connected to the flange hole (13); the first gas hose (9) is connected to the probe-specific gas circuit tool (8) through the first ferrule connector (7), the first gas hose (9) is connected to the first metal gas pipe (12) through the second ferrule connector (10), the first metal gas pipe (12) is connected to the second metal gas pipe (27) through the third ferrule connector (18), and the second metal gas pipe (27) is connected to the vacuum pump (22) through the fourth ferrule connector (21).

4. The in-situ detection method for particle spectrum concentration in a low-pressure chamber according to claim 1, characterized in that: A horn-shaped air inlet (5) is provided on the probe-specific gas path fixture (8) in the direction of the airborne particle spectrum probe instrument (1).

5. The in-situ detection method for particle spectrum concentration in a low-pressure chamber according to claim 1, characterized in that: The probe laser window (23) and probe detection window (24) are provided on the probe-specific gas path fixture (8).

6. The in-situ detection method for particle spectrum concentration in a low-pressure chamber according to claim 1, characterized in that: The airborne particle spectrum probe instrument (1) is equipped with a vacuum waterproof flight plug (25), which is connected to the data processing and control system (19) via a communication power supply cable (4).

7. The in-situ detection method for particle spectrum concentration in a low-pressure chamber according to claim 6, characterized in that: A vacuum penetration connector (16) is provided on the low-pressure chamber wall (2), and the communication power supply cable (4) passes through the vacuum penetration connector (16).

8. The in-situ detection method for particle spectrum concentration in a low-pressure chamber according to claim 1, characterized in that: The data processing and control system (19) is used for data acquisition and processing, and for controlling the vacuum solenoid valve (15) and the mass flow controller (20), including: Data processing module: used to acquire particle spectrum concentration data measured by the airborne particle spectrum probe instrument (1), to acquire wind speed data measured by the MEMS anemometer (26), and to acquire flow rate data measured by the mass flow controller (20); Automatic control module: used to control the flow rate of the mass flow controller (20) and to control the opening and closing of the vacuum solenoid valve (15).

9. The in-situ detection method for particle spectrum concentration in a low-pressure chamber according to claim 1, characterized in that: The detection position of the airborne particle spectrum probe instrument (1) is located at the center of the particle measurement coupling duct.

Images