Particulate matter detection instrument based on resistance-type particulate matter sensor and use method of particulate matter detection instrument

Abstract

The invention relates to the technical field of urban road particulate matter characteristic measurement, in particular to a particulate matter detection instrument based on a resistance-type particulate matter sensor and a using method thereof, and the particulate matter detection instrument comprises a protection box body, a sampling device, a sensor cleaning device, a detection device, a data processing device and a data sending device; the sensor cleaning device, the detection device, the data processing device and the data sending device are arranged in the protection box body; under the synergistic effect of the device with the structure, the total number of particles and the proportion of soot particles, rubber particles and other friction and wear particles are analyzed and calculated by detecting a conductivity change function between the interdigital electrodes and combining laboratory calibration data, and the tail gas particles and the wear particles are detected on line at the same time; moreover, the system is compact in size, simple in structure, free of operation and maintenance by professionals, and more suitable for large-scale deployment and remote automatic operation.

Description

Technical Field

[0001] The present invention relates to the technical field of measuring the characteristics of particulate matter on urban roads, and particularly relates to a particulate matter detection instrument based on a resistive particulate matter sensor and a method for using the same. Background Art

[0002] With the rapid development of the urbanization process and the sharp increase in the number of motor vehicles, the urban air quality has attracted more and more attention. Particulate matter pollution, especially fine particulate matter (PM2.5) with a diameter less than or equal to 2.5 micrometers and inhalable particulate matter (PM10) with a diameter less than 10 micrometers, has a profound impact on human health and the environment. The main sources of particulate matter on urban roads can be divided into two categories: particulate matter emitted from vehicle exhaust and non-exhaust particulate matter (particulate matter generated by the friction and wear of brake pads and tires). In recent years, with the gradual increase in the number of electric vehicles, the proportion of non-exhaust particulate matter in the particulate matter generated by road vehicles has shown an upward trend. Future vehicle emission regulations will impose stricter restrictions on the emissions of non-exhaust particulate matter. Therefore, it is particularly important to monitor the emissions of particulate matter on urban roads in real time. By deploying particulate matter detection instruments, the spatio-temporal distribution law of particulate matter concentration can be dynamically grasped, providing technical support for environmental protection departments to formulate scientific and reasonable emission regulations and emission reduction policies.

[0003] Existing particulate matter detection technologies mainly rely on beta-ray type, oscillating microbalance type, and light scattering type particulate matter detection equipment. Although the detection accuracy is relatively high, there are many drawbacks. At present, existing particulate matter detection equipment can only monitor the number of particulate matter and cannot distinguish between vehicle exhaust particulate matter and friction and wear particulate matter and their relative proportions. Moreover, the operating cost is high, making it not suitable for large-scale deployment and automated operation. Summary of the Invention

[0004] The purpose of the present application is to provide a particulate matter detection instrument based on a resistive particulate matter sensor and a method for using the same to solve the technical problems raised in the above background art.

[0005] The technical solutions adopted by the present application to solve the above technical problems are as follows: A particulate matter detection instrument based on a resistive particulate matter sensor includes a protection box body, a sampling device, a sensor cleaning device, a detection device, a data processing device, and a data sending device; the sensor cleaning device, the detection device, the data processing device, and the data sending device are arranged inside the protection box body; The sampling device includes a dust-proof cover, an electric lifting device, an air filter, a vacuum pump, a heater, and a thermophoresis; The dust cover includes a dust cover housing, an intake filter, an air inlet, a fan blade, a fan blade base, a dust outlet, and a dust cover air outlet; an intake filter is arranged inside the air inlet, and the fan blade base is fixed inside the dust cover housing to provide support for the fan blade; The electric lifter includes: a motor, a worm, a gear, a hollow spiral lifting rod, and a motor housing; the motor housing is fixed inside the protection box, and the motor, the worm, and the gear are placed inside the housing. The motor is fixedly placed and connected to the worm, the worm meshes with the gear, and the gear meshes with the hollow spiral lifting rod; the motor drives the worm to rotate, and the worm drives the gear to rotate so that the hollow spiral lifting rod rises or falls; The detection device includes: a humidity detection module and a resistive particulate matter sensor. The humidity detection module is used to detect the atmospheric humidity data of the working environment, and the resistive particulate matter sensor is used to detect the atmospheric particulate matter quantity data of the working environment; The sensor cleaning device includes: an air pump, an air filter, a blowing nozzle, a first air duct, and a second air duct; the first air duct connects the air outlet of the air pump and the air inlet of the air filter, and the second air duct connects the air outlet of the air filter and the blowing nozzle.

[0006] Further, the resistive particulate matter sensor includes: an alumina ceramic substrate, and the alumina ceramic substrate has a supporting function; A sensor element part for measuring the number of particulate matters in the gas. The sensor element part includes a first interdigital electrode and a second interdigital electrode. Among them, the first interdigital electrode and the second interdigital electrode are arranged in contact with one surface of the alumina ceramic substrate, and a predetermined voltage is set between the first interdigital electrode and the second interdigital electrode to detect the number of particulate matters aggregated between the first interdigital electrode and the second interdigital electrode, so as to calculate the particulate matter data of the urban road; A ceramic heating electrode, which is arranged in contact with the other surface of the alumina ceramic substrate, and the ceramic heating electrode heats the alumina ceramic substrate, the first interdigital electrode, and the second interdigital electrode; A control part, which includes a temperature control part and a voltage control part. After detecting the conductance data for a predetermined time, the voltage control part controls the voltage between the first interdigital electrode and the second interdigital electrode to zero, and the temperature control part controls the ceramic heating electrode to rise to a set temperature so as to burn the combustible particulate matters between the first interdigital electrode and the second interdigital electrode.

[0007] Further, the internal negative pressure causes air to enter from the air inlet. The air intake filter prevents large objects from entering and causing blockage. The air entering the inside of the dust-proof cover drives the fan blades to rotate. Under the action of centrifugal force, large dust and water droplets gather around the fan blades and leave the dust-proof cover through the dust outlet under the action of gravity.

[0008] Further, the dust-proof cover housing is connected to the hollow spiral lifting rod. The air outlet of the dust-proof cover is connected to the third air guide hose, and the third air guide hose is placed inside the hollow spiral lifting rod; The outlet of the third air guide hose is connected to the air inlet of the air filter. The fourth air duct connects the air outlet of the air filter to the air inlet of the vacuum pump. The air outlet of the vacuum pump is connected to the metal air duct, and the metal air duct passes through the heater to heat the gas inside the metal air duct to a predetermined temperature.

[0009] Further, the thermophoresis includes: a heat preservation housing, an upper substrate, a lower substrate, an upper heating electrode, and a lower heating electrode. The upper heating electrode is built into the upper substrate. The lower heating electrode is built into the lower substrate, and the resistive particle sensor is placed on the upper surface of the lower substrate. The air outlet of the metal air duct is connected to the thermophoresis air inlet, and the thermophoresis air outlet is connected to the exhaust pipe.

[0010] Further, the data processing device includes: a microcontroller MCU. The microcontroller MCU receives the data from the humidity detection module to determine whether it is in the working condition of the particulate matter detection instrument. The microcontroller MCU controls the electric lifting device to adjust the sampling height. The microcontroller MCU controls the vacuum pump to control the start or end of sampling. The microcontroller MCU controls the air pump to control the start or end of the sensor cleaning device. The microcontroller MCU controls the heater to start heating to a specific temperature. The microcontroller MCU controls the resistive particulate matter sensor to start or end detection. The microcontroller MCU controls the thermophoresis to heat to a specific temperature. The microcontroller MCU receives and processes the data detected by the resistive particulate matter sensor. The microcontroller MCU stores and uploads the processing result to the communication module.

[0011] The data sending device includes: a communication module CM. The communication module CM receives the data from the microcontroller MCU and uploads the data to the data monitoring center.

[0012] The present invention also discloses a usage method of the above particulate matter detection instrument based on a resistive particulate matter sensor, and the specific steps are as follows: S1. Deploy a number of the particulate matter detection instruments on the urban roads to be detected to form a detection network; S2. By operating the vacuum pump to generate a suction effect, the air on the urban road is drawn in through the dust cover. The dust cover conducts a preliminary filtration of the air to prevent dust from entering the detection device; S3. The preliminarily filtered air enters the air filter, and the air filter conducts a fine filtration of the air to remove large particulate matters with a diameter of 20 and above; S4. The finely filtered air is heated to 110 °C in the heater and then enters the thermophoresis; S5. The upper substrate of the thermophoresis is preheated to 250 °C, and the lower substrate is preheated to 110 °C to prevent moisture in the air from condensing, and to cause the particulate matters in the air to deposit on the resistive particulate matter sensor; S6. The resistive particulate matter sensor starts to work. A specified voltage is applied between the first interdigital electrode and the second interdigital electrode to detect the conductance change function within a specified time. The ceramic heating electrode raises the temperature of the alumina ceramic substrate to 450 °C and maintains it for 60 s, and detects the conductance change function during this time. The ceramic heating electrode raises the temperature of the alumina ceramic substrate to 700 °C and maintains it for 90 s, and detects the conductance change function during this time; S7. After the detection is completed, the voltage between the first interdigital electrode and the second interdigital electrode of the resistive particulate matter sensor is reset to zero, and the detection data is transmitted to the microcontroller MCU; S8. The ceramic heating electrode raises the temperature of the alumina ceramic substrate to 800 °C and maintains it for 90 s to cause the particulate matters to oxidize and burn; S9. After the particulate matters finish oxidizing and burning, the ceramic heating electrode stops working, and the air pump starts to work. The inhaled air is filtered by the air filter, and particulate matters with a diameter of 1 and above are removed. The filtered air passes through the purge nozzle to purge the non-exhaust particulate matters between the first interdigital electrode and the second interdigital electrode, and to cool down the alumina ceramic substrate. The purge time is 20 s - 30 s; S10. Prepare for the next detection; S11. The microcontroller MCU processes the data, stores the results, and then sends them to the communication module CM; S12. The communication module CM uploads the detection results to the data monitoring center.

[0013] The beneficial effects of the present invention are as follows: The particulate matter detection instrument of the present invention is provided with an automatic lifting device, which can provide support and automatic lifting for the sampling port, so as to achieve sampling at different heights; it is provided with a resistive particulate matter sensor, which can detect the data of the change in conductivity caused by the accumulation of particulate matter within a certain period of time, and the cost is relatively lower; the sensor cleaning device in the present invention can quickly clean the sensor so that the sensor can be quickly prepared for re-detection; the thermophoresis device can quickly accumulate particulate matter between the interdigitated electrodes of the sensor to achieve a rapid response of the sensor; the microcontroller MCU can process and calculate the detected particulate matter data and realize the unmanned operation of the particulate matter detection device; a communication module is set up, which can remotely monitor the particulate matter detection data. Under the synergistic effect of the above structural devices, the present invention calculates the total number of particulate matter and the proportions of soot particles, rubber particles, and other friction and wear particles by detecting the conductivity change function between the interdigitated electrodes and combining the laboratory calibration data analysis, so as to realize the simultaneous on-line detection of exhaust particulate matter and wear particulate matter; moreover, the present invention is compact in volume and simple in structure, does not require professional personnel for operation and maintenance, and is more suitable for large-scale deployment and remote automated operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to these drawings; Figure 1 It shows a schematic structural diagram of a resistive particulate matter sensor according to an exemplary embodiment of the present invention; Figure 2 It shows a schematic structural diagram of a particulate matter detection instrument according to an exemplary embodiment of the present invention; Figure 3 It shows a schematic structural diagram of electrophoresis, a particulate matter sensor, and a blowing nozzle according to an exemplary embodiment of the present invention; Figure 4 It shows a schematic structural diagram of a dust-proof cover according to an exemplary embodiment of the present invention; Figure 5 It shows a schematic structural diagram of an electric lifting device according to an exemplary embodiment of the present invention; Figure 6 It shows another view of the schematic structural diagram of the electric lifting device according to an exemplary embodiment of the present invention; The reference numerals in the figure are: 1, resistive particulate matter sensor; 11, alumina ceramic substrate; 12, first interdigital electrode; 13, second interdigital electrode; 14, ceramic heating electrode; 2, dust cover; 21, dust cover housing; 22, intake air filter; 23, intake port; 24, fan blade; 25, fan blade base; 26, dust outlet; 27, dust cover air outlet; 3, protection box; 4, electric lifting device; 41, motor; 42, worm; 43, gear; 44, hollow spiral lifting rod; 45 - motor housing; 5, air filter; 51, air filter; 6, vacuum pump; 7, heater; 8, thermophoresis; 81, thermophoresis heat preservation housing; 82, upper substrate; 821, upper substrate heating electrode; 83, lower substrate; 831, lower substrate heating electrode; 84, thermophoresis heat preservation wall; 9, air pump; 91, purge nozzle; 901, first air guide hose; 902, second air guide hose; 101, third air guide hose; 102, fourth air guide hose; 103, metal air duct; 104, exhaust pipe; 105, communication module CM; 106, humidity detection module; 107, microcontroller MCU. Detailed implementation mode

[0015] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application. Specific embodiment 1: As shown in the attached instructions of the present invention Figure 1 As shown, in order to solve the problems that existing particulate matter detection equipment can only monitor the number of particulate matter and cannot distinguish automotive exhaust particulate matter and friction and wear particulate matter and their relative proportions, and has high operating costs and is not suitable for large-scale deployment and automated operation, the present invention designs and provides a particulate matter detection instrument based on a resistive particulate matter sensor, including a protection box, a sampling device, a sensor cleaning device, a detection device, a data processing device, a data sending device, a third air guide hose 101, a fourth air guide hose 102, and a metal air duct 103; the sensor cleaning device, the detection device, the data processing device, and the data sending device are placed in the protection box.

[0017] The above sampling device includes: a dust-proof cover 2, an electric lifting device 4, an air filter 5, a vacuum pump 6, a heater 7, and a thermophoretic device 8; the outer shell 21 of the dust-proof cover is connected to the hollow spiral lifting rod 44, the air outlet 22 of the dust-proof cover is connected to the third air guide hose 101 and the third air guide hose 101 is placed inside the hollow spiral lifting rod 44, and the hollow spiral lifting rod 44 moves up and down through the electric lifting device 4; the outlet of the third air guide hose 101 is connected to the inlet of the air filter 5, the fourth air guide hose 102 connects the outlet of the air filter 5 to the inlet of the vacuum pump 6, the outlet of the vacuum pump 6 is connected to the metal air guide pipe 103, and the metal air guide pipe 103 passes through the heater 7 and is connected to the thermophoretic device 8, and the heater 7 heats the gas in the metal air guide pipe 103 to a predetermined temperature; the resistive particulate matter sensor body 1 is arranged inside the thermophoretic device 8.

[0018] The above resistive particulate matter sensor 1 includes: an alumina ceramic substrate 11, and the alumina ceramic substrate 11 has a supporting function; A sensor element part 1 for measuring the number of particulate matters in the gas, and the sensor element part includes a first interdigital electrode 12 and a second interdigital electrode 13. Among them, the first interdigital electrode 12 and the second interdigital electrode 13 are arranged in contact with one surface of the alumina ceramic substrate 11, and a predetermined voltage is set between the first interdigital electrode 12 and the second interdigital electrode 13 to detect the number of particulate matters aggregated between the first interdigital electrode 12 and the second interdigital electrode 13, so as to calculate the particulate matter data of urban roads; A ceramic heating electrode 14, and the ceramic heating electrode 14 is arranged in contact with the other surface of the alumina ceramic substrate 11, and the ceramic heating electrode 14 heats the alumina ceramic substrate 11 and the first interdigital electrode 12 and the second interdigital electrode 13; A control part 107, and the control part includes a temperature control part and a voltage control part. After detecting the conductance data for a predetermined time, the voltage control part controls the voltage between the first interdigital electrode 12 and the second interdigital electrode 13 to be zero, and the temperature control part controls the ceramic heating electrode 14 to rise to a set temperature so as to burn the combustible particulate matters between the first interdigital electrode 12 and the second interdigital electrode 13; When performing particulate matter measurement, the conductance of the interdigital electrodes to which a specified voltage is applied changes due to the accumulated particulate matter. The conductance change function (f1) between the first interdigital electrode 12 and the second interdigital electrode 13 within a specified time period (the time from when the conductance starts to change due to particulate matter accumulation to when the conductance stabilizes) is detected and recorded; the ceramic heating electrode 14 heats the alumina ceramic substrate 11 to 450 °C for 60 s to oxidize and burn the accumulated rubber particles, and the conductance change function (f2) during the oxidation and combustion of the rubber particles is recorded; the ceramic heating electrode 14 heats the alumina ceramic substrate 11 to 700 °C for 90 s to oxidize and burn the accumulated soot particles, and the conductance change function (f3) during the oxidation and combustion of the soot particles is recorded; the total number of particulate matters and the proportions of soot particles, rubber particles, and other friction and wear particles are analyzed and calculated by combining the laboratory calibration data with the conductance change functions (f1, f2, f3).

[0019] The above-mentioned sensor cleaning device includes: an air pump 9, an air filter 51, a purge nozzle 91, a first air duct 901 connecting the air outlet of the air pump 9 and the air inlet of the air filter 51, and a second air duct 902 connecting the air outlet of the air filter 51 and the purge nozzle 91.

[0020] The above-mentioned data processing device includes: a microcontroller MCU107. The functions of the microcontroller MCU107 are as follows: accepting the data of the humidity detection module 106 to judge whether it is in the working conditions of the particulate matter detection instrument; controlling the electric lifter 4 to adjust the sampling height; controlling the vacuum pump 6 to control the start or end of sampling; controlling the air pump 9 to control the start or end of sensor cleaning; controlling the heater 7 to start heating to a specific temperature; controlling the resistive particulate matter sensor 1 to start or end detection; controlling the thermophoresis 8 to heat to a specific temperature; accepting and processing the data detected by the resistive particulate matter sensor 1; storing and uploading the processing results to the communication module 105.

[0021] The above-mentioned data sending device includes: a communication module CM105. The communication module CM105 receives the data of the microcontroller MCU107 and uploads the data to the data monitoring center.

[0022] Combined with the attached drawings of the specification Figure 3As shown, in the above solution, the thermophoresis device 8 includes: a heat-insulating housing 81, an upper substrate 82, a lower substrate 83, an upper heating electrode 821, and a lower heating electrode 831. The upper substrate 82 has the upper heating electrode 821 built therein, and the lower substrate 83 has the lower heating electrode 831 built therein. The upper surface of the lower substrate 83 places the resistive particle sensor 1. The upper substrate 82 and the lower substrate 83 can be heated to a specific temperature by the heating electrodes to form a temperature gradient, so that the particulate matter in the gas is quickly deposited between the first interdigital electrode 12 and the second interdigital electrode 13 of the resistive particle sensor 1. The air enters the purge nozzle 91 after being filtered by the air filter 51 to purge the non-exhaust particulate matter between the first interdigital electrode 12 and the second interdigital electrode 13, and to cool the alumina ceramic substrate 11.

[0023] Combined with the attached drawings of the specification Figure 4 As shown, in the above solution, the dust cover 2 includes a dust cover housing 21, an intake air filter 22, an air inlet 23, a fan blade 24, a fan blade base 25, a dust outlet 26, and a dust cover air outlet 27. The intake air filter 22 is arranged inside the air inlet 23. The fan blade base 25 is fixed inside the dust cover housing 21 to provide support for the fan blade 24. The internal negative pressure causes air to enter from the air inlet 23. The intake air filter 22 prevents large objects from entering and causing blockage. The air entering the inside of the dust cover 2 drives the fan blade 24 to rotate. Under the action of centrifugal force, large dust and water droplets gather around the fan blade and leave the dust cover 2 through the dust outlet 26 under the action of gravity. The air in the central area of the fan blade enters the air duct 101 through the air inlet 23.

[0024] Combined with the attached drawings of the specification Figure 4 and the attached drawings of the specification Figure 5 As shown, in the above solution, the electric lifter 4 includes a motor housing 45, a motor 41, a worm 42, a gear 43, and a hollow spiral lifting rod 44. The motor housing 45 is fixed inside the protection box 3, and the motor 41, the worm 42, and the gear 43 are placed inside the motor housing 45. The motor 41 is fixedly placed and connected to the worm 42. The worm 42 meshes with the gear 43, and the gear 43 meshes with the hollow spiral lifting rod 44. The motor 41 drives the worm 42 to rotate, and the worm 42 drives the gear 43 to rotate, thereby causing the hollow spiral lifting rod 44 to rise or fall, and finally realizing the adjustable sampling height.

[0025] Combined with the attached drawings of the specification Figure 1 to the attached drawings of the specification Figure 6As shown in the figure, in combination with the above solution, the microcontroller MCU107 receives the ambient humidity data detected by the humidity detection module 106 and determines whether it is within the operating range of the particulate matter detection instrument. When it is within the operating range, it controls the vacuum pump 6 to start pumping air; the air is roughly filtered by the dust cover 2 and then finely filtered by the air filter 5, and then heated by the heater 7, and then enters the thermophoretic unit 8, and finally exits from the thermophoretic unit 8; the upper and lower substrates of the thermophoretic unit 8 form a temperature gradient to accumulate particulate matter on the resistive particulate matter sensor 1. The microcontroller MCU107 obtains the conductance change function between the first interdigital electrode 12 and the second interdigital electrode 13 detected by the resistive particulate matter sensor 1 within a specified time, and compares it with the conductance functions of automotive exhaust particulate matter and friction particulate matter, and calculates the quantity and proportion of automotive exhaust particulate matter and friction particulate matter; the microcontroller MCU107 makes the heating electrode 14 work to burn the automotive exhaust particulate matter, and after the combustion ends, the air pump is started to purge and clean the first interdigital electrode 12 and the second interdigital electrode 13 of the sensor. Specific Embodiment 2: Embodiment 2: A method for using a particulate matter detection instrument based on a resistive particulate matter sensor, including the following operating steps: S1. Deploy a number of the particulate matter detection instruments on the urban roads to be detected to form a detection network; S2. Through the operation of the vacuum pump 6 to generate a suction effect, the air on the urban road enters from the dust cover 2, and the dust cover 2 roughly filters the air to prevent dust from entering the detection device; S3. The air after rough filtration enters the air filter 5, and the air filter 5 finely filters the air to remove large particulate matter with a diameter of 20 and above; S4. The air after fine filtration is heated to 110 °C in the heater 7 and then enters the thermophoretic unit 8; S5. The upper substrate 82 of the thermophoretic unit 8 is preheated to 250 °C, and the lower substrate 83 is preheated to 110 °C to prevent moisture in the air from condensing, and to deposit the particulate matter in the air on the resistive particulate matter sensor 1; S6. The resistive particulate matter sensor 1 starts to work, a specified voltage is applied between the first interdigital electrode 12 and the second interdigital electrode 13, the conductance change function within a specified time is detected, the ceramic heating electrode 14 raises the temperature of the alumina ceramic substrate 11 to 450 °C and maintains it for 60 s, the conductance change function during this time is detected, the ceramic heating electrode 14 raises the temperature of the alumina ceramic substrate to 700 °C and maintains it for 90 s, and the conductance change function during this time is detected; S7. After the detection is completed, the voltage between the first interdigital electrode 12 and the second interdigital electrode 13 of the resistive particulate matter sensor 1 is reset to zero, and the detection data is transmitted to the microcontroller MCU107; S8. The ceramic heating electrode (14) raises the temperature of the alumina ceramic substrate to 800 °C and maintains it for 90 s to oxidize and burn the particulate matter; S9. After the oxidation and combustion of the particulate matter ends, the ceramic heating electrode 14 stops working, and the air pump 9 starts to work. The inhaled air is filtered by the air filter 51, and particulate matter with a size of 1 μm or more is filtered out. The filtered air passes through the purge nozzle 91 to purge the non-exhaust particulate matter between the first interdigital electrode 12 and the second interdigital electrode 13, and cools down the alumina ceramic substrate 11. The purge time is 20 s - 30 s; S10. Prepare for the next detection; S11. The microcontroller MCU107 processes the data and stores the results, and then sends them to the communication module CM105; S12. The communication module CM105 uploads the detection results to the data monitoring center. The environmental protection department can refer to the emission data of exhaust particulate matter and non-exhaust particulate matter displayed in the data center in real time for the policies to be implemented.

[0027] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and all these changes and improvements fall within the scope of the present invention claimed.

Claims

1. A particulate matter detection instrument based on a resistive particulate matter sensor, characterized in that, It includes a protection box body, a sampling device, a sensor cleaning device, a detection device, a data processing device, a data sending device, a third air guide hose (101), a fourth air guide hose (102), and a metal air duct (103);; (The air guide hose belongs to the sampling device and does not need to be written here) The sensor cleaning device, the detection device, the data processing device, and the data sending device are placed inside the protection box body; The sampling device includes a dust-proof cover (2), an electric lifting device (4), an air filter (5), a vacuum pump (6), a heater (7), and thermophoresis (8); The dust-proof cover (2) includes a dust-proof cover housing (21), an intake air filter (22), an air intake (23), a fan blade (24), a fan blade base (25), a dust outlet (26), and a dust-proof cover air outlet (27); An intake air filter (22) is arranged inside the air intake (23), and the fan blade base (25) is fixed inside the dust-proof cover housing (21) to provide support for the fan blade (24); The electric lifter (4) includes: a motor (41), a worm (42), a gear (43), a hollow spiral lifting rod (44), and a motor housing (45); The motor housing (45) is fixed inside the protection box body (3), and the motor (41), the worm (42), and the gear (43) are placed inside the housing (45). The motor (41) is fixedly placed and connected to the worm (42), the worm (42) meshes with the gear (43), and the gear (43) meshes with the hollow spiral lifting rod (44); The motor (41) drives the worm (42) to rotate, and the worm (42) drives the gear (43) to rotate, thereby causing the hollow spiral lifting rod (44) to rise or fall; The detection device includes: a humidity detection module (106) and a resistive particulate matter sensor (1). The humidity detection module (106) is used to detect the atmospheric humidity data of the working environment, and the resistive particulate matter sensor (1) is used to detect the atmospheric particulate matter quantity data of the working environment; The sensor cleaning device includes: an air pump (9), an air filter (51), a blowing nozzle (91), a first air duct (901), and a second air duct (902); The first air duct (901) connects the air outlet of the air pump (9) and the air inlet of the air filter (51), and the second air duct (902) connects the air outlet of the air filter (51) and the blowing nozzle (91).

2. The particulate matter detection instrument based on a resistive particulate matter sensor according to claim 1, wherein The resistive particulate matter sensor (1) includes: an alumina ceramic substrate (11), and the alumina ceramic substrate (11) has a supporting function; A sensor element portion (1) for measuring the number of particulate matters in a gas, the sensor element portion including a first interdigital electrode (12) and a second interdigital electrode (13), wherein the first interdigital electrode (12) and the second interdigital electrode (13) are arranged in contact with one surface of the alumina ceramic substrate (11), and a predetermined voltage is set between the first interdigital electrode (12) and the second interdigital electrode (13) to detect the number of particulate matters aggregated between the first interdigital electrode (12) and the second interdigital electrode (13) for calculating the particulate matter data of urban roads; A ceramic heating electrode (14) arranged in contact with the other surface of the alumina ceramic substrate (11), the ceramic heating electrode (14) heating the alumina ceramic substrate (11), the first interdigital electrode (12) and the second interdigital electrode (13); A control portion (107) including a temperature control portion and a voltage control portion. After detecting the conductance data for a predetermined time, the voltage control portion controls the voltage between the first interdigital electrode (12) and the second interdigital electrode (13) to be zero, and the temperature control portion controls the ceramic heating electrode (14) to heat up to a set temperature to burn the combustible particulate matters between the first interdigital electrode (12) and the second interdigital electrode (13).

3. The particulate matter detection instrument based on a resistive particulate matter sensor according to claim 1, characterized in that, The internal negative pressure causes air to enter from the air inlet (23). The air intake filter (22) prevents large objects from entering and causing blockage. The air entering the interior of the dust-proof cover (2) drives the fan blade (24) to rotate. Under the action of centrifugal force, large dust and water droplets are aggregated around the fan blade (24) and leave the dust-proof cover (2) through the dust outlet (26) under the action of gravity.

4. A particulate matter detection instrument based on a resistive particulate matter sensor according to claim 3, characterized in that, The dust-proof cover housing (21) is connected to the hollow spiral lifting rod (44). The air outlet (27) of the dust-proof cover is connected to the third air guide hose (101) and the third air guide hose (101) is placed inside the hollow spiral lifting rod (44); The outlet of the third air guide hose (101) is connected to the air inlet of the air filter (5). The fourth air duct (102) connects the air outlet of the air filter (5) to the air inlet of the vacuum pump (6). The air outlet of the vacuum pump (6) is connected to the metal air duct (103), and the metal air duct (103) passes through the heater (7) to heat the gas inside the metal air duct (103) to a predetermined temperature.

5. A particulate matter detection instrument based on a resistive particulate matter sensor according to claim 1, characterized in that, The thermophoresis device (8) includes: a heat preservation housing (81), an upper substrate (82), a lower substrate (83), an upper heating electrode (821), and a lower heating electrode (831). The upper heating electrode (821) is built in the upper substrate, the lower heating electrode (831) is built in the lower substrate (83), and the resistive particle sensor (1) is placed on the upper surface of the lower substrate. The outlet of the metal air duct (103) is connected to the air inlet of the thermophoresis device (8), and the air outlet of the thermophoresis device (8) is connected to the exhaust pipe (104).

6. The particulate matter detection instrument based on a resistive particulate matter sensor according to claim 1, characterized in that, The data processing device includes: a microcontroller MCU (107), which receives the data from the humidity detection module (106) to determine whether it is in the working conditions of the particulate matter detection instrument, controls the electric lifting device (4) to adjust the sampling height, controls the vacuum pump (6) to control the start or end of sampling, controls the air pump (9) to control the start or end of the sensor cleaning device, controls the heater (7) to start heating to a specific temperature, controls the resistive particulate matter sensor (1) to start or end detection, controls the thermophoresis (8) to heat to a specific temperature, receives and processes the data detected by the resistive particulate matter sensor (1), and stores and uploads the processing result to the communication module (105).

7. A particulate matter detection instrument based on a resistive particulate matter sensor according to claim 6, characterized in that, The data sending device includes: a communication module CM (105), which receives the data from the microcontroller MCU (107) and uploads the data to the data monitoring center.

8. The method of using a particulate matter detection instrument based on a resistive particulate matter sensor according to any one of claims 1-7, characterized in that The specific steps are as follows: S1. Deploy the particulate matter detection instrument on the urban roads to be detected to form a detection network; S2. The vacuum pump (6) operates to generate a suction effect, so that the air on the urban road enters from the dust-proof cover (2), and the dust-proof cover (2) filters the air roughly to prevent dust from entering the detection device; S3. The air after coarse filtration enters the air filter (5), and the air filter (5) performs fine filtration on the air to remove large particles with a diameter of 20 or more; S4. The air after fine filtration is heated to 110 °C in the heater (7) and then enters the thermophoresis (8); S5. The upper substrate (82) of the thermophoresis (8) is preheated to 250 °C, and the lower substrate (83) is preheated to 110 °C to prevent moisture in the air from condensing, and make the particulate matter in the air deposit on the resistive particulate matter sensor (1); S6. The resistive particulate matter sensor (1) starts to work, a specified voltage is applied between the first interdigital electrode (12) and the second interdigital electrode (13), the conductance change function within a specified time is detected, the ceramic heating electrode (14) raises the temperature of the alumina ceramic substrate (11) to 450 °C and lasts for 60 s, the conductance change function within this time is detected, the ceramic heating electrode (14) raises the temperature of the alumina ceramic substrate to 700 °C and lasts for 90 s, and the conductance change function within this time is detected; S7. After the detection is completed, the voltage between the first interdigital electrode (12) and the second interdigital electrode (13) of the resistive particulate matter sensor (1) is reset to zero, and the detected data is transmitted to the microcontroller MCU (107); S8. The ceramic heating electrode (14) raises the temperature of the alumina ceramic substrate to 800 °C and lasts for 90 s to oxidize and burn the particulate matter; After the oxidation and combustion of the exhaust gas particulate matter, the ceramic heating electrode (14) stops working, and the air pump (9) starts to work. The inhaled air is filtered by the air filter (51), and particulate matter with a size of 1 μm or more is filtered out. The filtered air passes through the purge nozzle (91) to purge the non-exhaust gas particulate matter between the first interdigital electrode (12) and the second interdigital electrode (13), and to cool the alumina ceramic substrate (11). The purge time is 20 s - 30 s; (should be 20 s - 30 s) S9S10. Prepare for the next detection; S10S11. After the microcontroller MCU (107) processes data and stores the results, it sends them to the communication module CM (105); S11S12. The communication module CM (105) uploads the detection results to the data monitoring center.

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