A portable high-precision ambient air particulate matter sampling analyzer

Abstract

The present invention relates to the technical field of particulate matter detectors, and specifically discloses a portable high-precision ambient air particulate matter sampling and analyzing instrument, which includes a main body, a sampling and analyzing mechanism, a paper feeding mechanism, a paper feeding mechanism moving drive device, a sampling nozzle lifting device, and an automatic calibration device. A substrate is installed in the main body, and the sampling and analyzing mechanism is installed on the substrate. The paper feeding mechanism is arranged below the sampling and analyzing mechanism. The paper feeding mechanism is connected to the paper feeding mechanism moving drive device. The sampling nozzle lifting device and the automatic calibration device are fixed on the opposite side of the substrate where the sampling and analyzing mechanism is located. The outside of the main body is also connected with a particulate matter cutter, a sampling tube, a dynamic heating tube, a temperature and humidity sensor, a tripod, an external sampling pump, a GPS, and a GPRS antenna. The overall structure of the device is reasonably arranged, with an automatic calibration device, the sampling pump and the dynamic heating tube are external, the main body is small in volume, light in weight, and high in analysis precision.

Description

Technical Field

[0001] The present invention belongs to the technical field of particulate matter sampling analyzers, and particularly relates to a portable high-precision ambient air particulate matter sampling analyzer. Background Art

[0002] In the field of environmental monitoring and treatment, suspended particulate matter is an important general pollution index in the evaluation of ambient air quality. Among the methods for monitoring ambient air particulate matter, the beta-ray method has stable performance and relatively mature technology, and can perform long-term automatic sampling and analysis.

[0003] Compared with the online beta-ray analyzer that needs to operate in a constant temperature and humidity chamber, the portable beta-ray analyzer is easy to carry, does not require the construction of a constant temperature and humidity environment, is convenient to arrange, and has low cost, and is more suitable for outdoor sampling point monitoring. At the same time, compared with online instruments, the portable beta-ray analyzer faces more severe environmental conditions. How to ensure its accuracy and stability in the changing outdoor environment is an important research topic.

[0004] Some existing portable beta-ray analyzers have no automatic calibration mechanism, adopt a layout method (in-situ method) where sampling and analysis are at the same station, the paper tape moves multiple times between two stations in a way of curling in two directions, there is no paper tape tension control, there is no paper tape vertical positioning function at the analysis station, the sampling pump is built into the main housing, and there are many problems such as the inability to use a standard diaphragm to achieve temperature compensation function, affecting the analysis accuracy in a complex temperature environment, the sampling is easily affected by the changing outdoor environment, the paper tape positioning error is large and the tension is not constant, affecting the analysis accuracy, and the overall volume and weight of the main body are large. Summary of the Invention

[0005] The purpose of the present invention is to provide a portable high-precision ambient air particulate matter sampling analyzer, mainly to solve the problems of errors in sampling and analysis accuracy and large volume of existing particulate matter sampling analyzers.

[0006] To achieve the above object, the present invention provides the following technical solution: A portable high-precision ambient air particulate matter sampling analyzer, including a main body, a substrate is arranged inside the main body, and further includes a sampling and analysis mechanism, a paper feeding mechanism, a paper feeding mechanism moving drive device, a sampling nozzle lifting device, and an automatic calibration device. The sampling and analysis mechanism is installed on the substrate, the paper feeding mechanism is arranged below the sampling and analysis mechanism, the paper feeding mechanism is connected with the paper feeding mechanism moving drive device, and the sampling nozzle lifting device and the automatic calibration device are fixed on the opposite side of the substrate where the sampling and analysis mechanism is located.

[0007] Preferably, the sampling and analysis mechanism includes a sampling nozzle, a radiation source, a beta-ray detector, an analysis module fixing block, a downstream rectifying tube, and a detector paper guide roller. The radiation source and the beta-ray detector are fixed on the substrate through the analysis module fixing block. The sampling nozzle is fixed in the middle of the analysis module fixing block. The downstream rectifying tube is fixed at the lower part of the analysis module fixing plate, directly below the sampling nozzle. The detector paper guide roller is fixed on both sides of the radiation source, and the beta-ray detector is fixed directly above the radiation source.

[0008] Preferably, the paper feeding mechanism includes a mounting plate, a counting wheel assembly, two paper guide wheel assemblies, a tensioning wheel assembly, a paper feeding wheel assembly, a paper receiving wheel assembly, a filter paper belt, and a filter paper belt pressing plate. The counting wheel assembly and one paper guide wheel assembly are fixed at the same height on the mounting plate. The tensioning wheel assembly is fixed on the mounting plate below the counting wheel assembly and is at the same height as the other paper guide wheel assembly on the mounting plate. The paper feeding wheel assembly and the paper receiving wheel assembly are fixed on the mounting plate below the tensioning wheel assembly and the paper guide wheel assembly and are at the same height on the mounting plate. The filter paper belt pressing plate is fixed on the paper feeding wheel assembly and the paper receiving wheel assembly, and the filter paper belt is wound around the counting wheel assembly, the paper guide wheel assembly, the tensioning wheel assembly, the paper feeding wheel assembly, and the paper receiving wheel assembly.

[0009] Preferably, it further includes a first slot-type optocoupler and a second slot-type optocoupler, which are respectively fixed on the substrate above the counting wheel assembly.

[0010] Preferably, the tensioning wheel assembly includes a wheel shaft, a tensioning wheel, a linear guide rail, a movable plate, a tensioning spring, a third slot-type optocoupler, and a fourth slot-type optocoupler. The linear guide rail is fixed on the mounting plate. The movable plate moves left and right on the linear guide rail. The wheel shaft is connected to the movable plate. The tensioning wheel is connected to the wheel shaft. One end of the tensioning spring is connected to the movable plate, and the other end is fixedly connected to the mounting plate. The third slot-type optocoupler and the fourth slot-type optocoupler are fixed on the mounting plate below the movable plate.

[0011] Preferably, the sampling nozzle lifting device includes a driving motor, a first eccentric shaft, a spring positioning sleeve, a first rolling bearing, and a self-lubricating bushing. The spring positioning sleeve is sleeved outside the sampling nozzle. The driving motor is connected to the first eccentric shaft. The working end of the first eccentric shaft is connected to the first rolling bearing. The lower edge of the spring positioning sleeve tightly presses the outer ring of the first rolling bearing. The sampling nozzle is connected to the analysis module fixing block through the self-lubricating bushing. The sampling nozzle lifting device further includes a first code disk, a machine shell, and a fifth slot-type optocoupler. The first code disk is sleeved on the first eccentric shaft. The machine shell covers part of the first eccentric shaft and the first code disk. The driving motor is fixed on one side of the machine shell. The fifth slot-type optocoupler is fixed on the machine shell, directly opposite the first code disk.

[0012] Preferably, the automatic calibration device includes a standard diaphragm assembly, a dial plate, a dial plate central shaft, a torsion spring, a driving device, a second eccentric shaft, and a second rolling bearing. The driving device is connected to the second eccentric shaft. The working end of the second eccentric shaft is connected to the second rolling bearing. The working end of the dial plate central shaft is connected to the dial plate. The other end of the dial plate central shaft is connected to the torsion spring. The dial plate is pressed against the outer ring of the second rolling bearing under the torsional force of the torsion spring. The automatic calibration device further includes a fixed seat for the calibration driving device, a second code disk, and a sixth groove-shaped optocoupler. The driving device is fixedly connected to the fixed seat for the calibration driving device. The second code disk is sleeved on the second eccentric shaft. The sixth groove-shaped optocoupler is fixed on the fixed seat for the calibration driving device.

[0013] Preferably, the standard diaphragm assembly includes a diaphragm fixing plate, a standard diaphragm chamber, a self-lubricating guide plate, and a load equalizing plate. The standard diaphragm is fixed on the diaphragm fixing plate. The standard diaphragm chamber is provided with an oblong slot. The diaphragm fixing plate is provided with a fixing pin. The diaphragm fixing plate moves in and out of the standard diaphragm chamber under the pulling and pushing of the dial plate and the movement of the fixing pin in the oblong slot. The self-lubricating guide plate and the load equalizing plate are arranged in sequence on the upper part of the diaphragm fixing plate and are fastened in the standard diaphragm chamber.

[0014] Preferably, a particulate matter cutter, a sampling tube, a dynamic heating tube, a temperature and humidity sensor, a tripod, an external sampling pump, a GPS, and a GPRS antenna are further connected to the outside of the main machine. The particulate matter cutter is connected to the sampling tube. The dynamic heating tube is fixed outside the sampling tube. The temperature and humidity sensor, the GPS, and the GPRS antenna are fixed outside the main machine. The tripod supports the main machine below.

[0015] Preferably, the external sampling pump includes a housing, a bracket, a handle, an air duct deflector, a cooling fan, a thermostat, a vacuum pump, and an exhaust muffler. The handle is fixed on the top of the housing, the bracket is fixed on the lower part, the air duct deflector is fixed on the side, the cooling fan, the vacuum pump, and the thermostat are fixed inside. The exhaust muffler is connected to the vacuum pump.

[0016] Advantages of the present invention:

[0017] The overall structural layout of the analyzer of the present invention is reasonable.

[0018] 1. The main machine is internally provided with an automatic calibration mechanism, which can utilize the standard diaphragm to realize the temperature compensation function and improve the analysis accuracy of the instrument in a complex environment.

[0019] 2. In the sampling and analysis mechanism, the sampling and analysis are arranged at two stations. The filter paper tape moves back and forth between the two stations through the paper feeding mechanism. It has a counting wheel assembly and a tensioning wheel assembly to realize the precise positioning of the paper tape. The tension of the paper tape will not change, avoiding the introduction of additional errors and ensuring the analysis accuracy.

[0020] 3. When the winding length of the filter paper tape set by the program remains unchanged, since the moving trajectory and length of the tension wheel assembly are fixed values, the tension force on the filter paper tape can be guaranteed to be constant, and the tension value of the filter paper tape between each sampling and analysis cycle is basically unchanged, avoiding positioning accuracy errors caused by different tension values ​​of the filter paper tape and changes in the thickness of the filter paper tape due to different tensions, which affect the analysis accuracy;

[0021] 4. Fix the detector paper guide rollers on both sides of the radiation source. The height of the detector paper guide rollers in the vertical direction is slightly higher than that of the counting wheel and the paper guide wheel in the vertical direction. There is a certain height difference, so that the filter paper belt is tightly attached to the common tangent line of the top surface of the two detector paper guide rollers under the action of tension, which can ensure that the filter paper belt always remains consistent in the vertical direction of the space of this analysis station, and can eliminate the arched cross-section of the filter paper belt formed under the action of tension, thereby improving the accuracy and stability of the measurement analysis here, and avoiding the displacement and deformation of the filter paper belt in the vertical direction between the radiation source and the β-ray detector, which affects the analysis accuracy;

[0022] 5. The analysis module fixing block carries the fixed installation of sampling and analysis modules such as sampling nozzle, rectifier tube, radiation source, and detector paper guide roller. It is integrated with the ultra-high processing precision of the machine tool to ensure the relative position accuracy of the components installed on it, avoiding the distance error between the sampling and analysis stations, and the distance error between the radiation source and the detector, which is easy to occur during installation or after a long period of use, affecting the analysis accuracy;

[0023] 6. A rectifier tube is installed downstream of the sampling station to ensure that the particles are evenly distributed on the filter paper belt, avoiding the inconsistency between the air inlet and outlet directions of the downstream cavity, and the "air flow short circuit" that introduces the problem of uneven distribution of particles, thereby improving the analysis accuracy of the instrument;

[0024] 7. The gas path system from the sampling tube to the filter paper belt has been optimized and designed to present a smooth transition without protruding structures, which will not cause particle retention and ensure the accuracy of the sampling sample;

[0025] 8. The sampling pump is external, which reduces the volume and weight of the main unit. At the same time, the vibration and heat of the sampling pump will not affect the accuracy of the instrument;

[0026] 9. With GPS positioning and GPRS data transmission functions, it is suitable for outdoor use and reduces maintenance costs;

[0027] 10. The dynamic heating tube is placed outside the main housing and has a waterproof design to avoid the impact of heat on the main unit. At the same time, the up and down position can be easily adjusted to the most suitable position. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the mounting structure of the substrate surface A inside the host of the present invention;

[0029] Figure 2 Schematic diagram of the installation structure of the B side of the internal substrate of the host of the present invention;

[0030] Figure 3 Schematic diagram of the overall structure of the particulate matter sampling analyzer of the present invention;

[0031] Figure 4 Schematic diagram of the structure of the paper feeding mechanism of the present invention;

[0032] Figure 5 Another schematic diagram of the structure of the paper feeding mechanism of the present invention;

[0033] Figure 6 Schematic diagram of the structure of the moving drive device of the paper feeding mechanism of the present invention;

[0034] Figure 7 Schematic diagram of the structure of the sampling and analysis mechanism of the present invention;

[0035] Figure 8 Schematic diagram of the structure of the sampling nozzle lifting device of the present invention;

[0036] Figure 9 Schematic diagram of the structure of the automatic calibration device of the present invention;

[0037] Figure 10 Another schematic diagram of the structure of the automatic calibration device of the present invention;

[0038] Figure 11 Another schematic diagram of the structure of the automatic calibration device of the present invention;

[0039] Figure 12 Schematic diagram of the structure of the standard diaphragm assembly of the present invention;

[0040] Figure 13 Schematic diagram of the internal structure of the external sampling pump of the present invention;

[0041] Figure 14 Schematic diagram of the external structure of the external sampling pump of the present invention;

[0042] Figure 15 Schematic diagram of the folding of the bracket of the external sampling pump of the present invention.

[0043] Annotations in the figure:

[0044] Mainframe 1, sampling and analysis mechanism 2, paper feeding mechanism 3, paper feeding mechanism moving drive device 4, sampling nozzle lifting device 5, automatic calibration device 6, first groove-shaped optocoupler 7, second groove-shaped optocoupler 8, particulate matter cutter 9, sampling tube 10, dynamic heating tube 11, temperature and humidity sensor 12, tripod 13, external sampling pump 14, GPS and GPRS antennas 15, substrate 16, counting wheel 17, paper guiding wheel 18, guide rail 160;

[0045] Sampling nozzle 201, radiation source 202, β-ray detector 203, analysis module fixing block 204, downstream rectifier tube 205, detector paper guiding roller 206;

[0046] Mounting plate 300, positioning surface 3001, counting wheel assembly 301, tensioning wheel assembly 302, linear guide rail 303, third groove-shaped optocoupler 304, fourth groove-shaped optocoupler 305, tensioning spring 306, paper feeding wheel assembly 307, paper receiving wheel assembly 308, filter paper tape 309, filter paper tape pressing plate 310, paper guiding wheel assembly 311, movable plate 3021, second wheel shaft 3022, tensioning wheel 3023;

[0047] Reduction motor 401, coupling 402, ball screw nut assembly 403, encoder 404, fixed side plate 405, L-shaped fixing seat 406;

[0048] Drive motor 501, first eccentric shaft 502, spring positioning sleeve 503, first rolling bearing 504, spring 505, first code disk 506, housing 507, fifth groove-shaped optocoupler 508, self-lubricating bushing 509, nozzle seal sleeve 510, sealing ring 511;

[0049] Standard diaphragm assembly 601, dial plate 602, dial plate central shaft 603, torsion spring 604, drive device 605, second eccentric shaft 606, second rolling bearing 607, calibration drive device fixing seat 608, second code disk 609, sixth groove-shaped optocoupler 610, second bearing 611, second bearing seat 612, standard diaphragm 6011, diaphragm fixing plate 6012, standard diaphragm bin 6013, self-lubricating guide plate 6014, load equalizing plate 6015, standard diaphragm 6011, diaphragm fixing plate 6012, standard diaphragm bin 6013, self-lubricating guide plate 6014, load equalizing plate 6015;

[0050] Shell 141, bracket 142, handle 143, air duct fairing 144, cooling fan 145, thermostat 146, vacuum pump 147, exhaust muffler 148, air inlet interface 149, air exhaust interface 140, lock card 1410, long slot 1420. Detailed implementation manners

[0051] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0052] Embodiment

[0053] As shown in the Figure 1-3 accompanying drawings, the following technical solutions are provided in this embodiment:

[0054] A portable high-precision ambient air particulate matter sampling analyzer, including a main unit 1. Inside the main unit 1, there are a sampling and analysis mechanism 2, a paper feeding mechanism 3, a paper feeding mechanism moving drive device 4, a sampling nozzle lifting device 5, an automatic calibration device 6, a first groove optical coupler 7, and a second groove optical coupler 8. The sampling and analysis mechanism 2 includes a sampling nozzle 201, a radiation source 202, and a β-ray detector 203, which are used to complete the sampling and analysis of particulate matter. The paper feeding mechanism 3 is used to release a new filter paper tape of a set length and recycle the old filter paper tape, while keeping the tension of the filter paper tape 309 constant. The paper feeding mechanism moving drive device 4 is used to drive the paper feeding mechanism 3 to move left and right, so that the filter paper tape 309 can be switched between the sampling and analysis stations of the sampling and analysis mechanism 2. The sampling nozzle lifting device 5 is used to drive the sampling nozzle 21 to lift or lower. The automatic calibration device 6 is used to drive the calibration diaphragm to extend or retract from the standard diaphragm chamber to complete the automatic calibration work. The first groove optical coupler 7 is used to determine the initial position of the movement of the paper feeding mechanism 3. The second groove optical coupler 8 is used to determine the limit position of the movement of the paper feeding mechanism 3 to prevent structural damage caused by the over-limit movement of the paper feeding mechanism 3.

[0055] Referring to Figure 2 , the outside of the main unit 1 is also connected with a particulate matter cutter 9, a sampling tube 10, a dynamic heating tube 11, a temperature and humidity sensor 12, a tripod 13, an external sampling pump 14, a GPS and GPRS antenna 15. The particulate matter cutter 9 is designed and processed according to national standards and is used to screen particulate matter within a certain particle size range and allow it to enter the sampling tube 10. The dynamic heating tube 11 is controlled by a program to adjust the air temperature flowing through the sampling tube 10 in real time. The sampling tube 10 connects the particulate matter cutter 9 and the main unit 1 to introduce the air containing particulate matter into the sampling station of the main unit 1. The temperature and humidity sensor 12 has a rain-proof device and can monitor the current air temperature and humidity in real time. The tripod 13 is made of aluminum alloy, which can reduce the weight of the whole machine and is used to support the main unit 1. The GPS and GPRS antenna 15 is used for the positioning of the analyzer and remote data transmission. The external sampling pump 14 has a rain-proof and water-accumulation-proof design and is used to provide suction power to make the air enter the main unit 1 from the particulate matter cutter 9 and be discharged.

[0056] As Figure 4 , 5 shown, a substrate 16 is provided inside the host 1. The paper feeding mechanism 3 includes a mounting plate 300, a counting wheel assembly 301, a tension wheel assembly 302, a third groove-shaped optocoupler 304, a fourth groove-shaped optocoupler 305, a paper feeding wheel assembly 307, a paper receiving wheel assembly 308, a filter paper belt 309, a filter paper belt pressing plate 310, and a paper guiding wheel assembly 311. The counting wheel assembly 301 and a paper guiding wheel assembly 311 are fixed at the same height on the mounting plate 300. The tension wheel assembly 302 is fixed on the mounting plate 300 below the counting wheel assembly 301 and is at the same height as the other paper guiding wheel assembly 311 on the mounting plate 300. The paper feeding wheel assembly 307 and the paper receiving wheel assembly 308 are fixed on the mounting plate 300 below the tension wheel assembly 302 and the paper guiding wheel assembly 311 and are at the same height on the mounting plate 300. The filter paper belt 309 is wound around the counting wheel assembly 301, the paper guiding wheel assembly 311, the tension wheel assembly 302, the paper feeding wheel assembly 307, and the paper receiving wheel assembly 308.

[0057] The mounting plate 300 is arranged on one side of the substrate 16. The counting wheel assembly 301 consists of a counting wheel 17, a first wheel shaft and an encoder, and is used for measuring and controlling the curling length of the filter paper tape 309. The encoder and the first wheel shaft are fixed on the A side of the mounting plate 300, and the first wheel shaft passes through the mounting plate 300 and is connected to a counting wheel 17 located on the B side of the mounting plate 300. The tensioning wheel assembly 302 consists of a linear guide rail 303, a movable plate 3021 fixed on the linear guide rail 303, a second wheel shaft 3022, a tensioning wheel 3023 and a tension spring 306. The movable plate 3021 can move left and right on the linear guide rail 303. One end of the tension spring 306 is connected to the movable plate 3021, and the other end is directly fixedly connected to the A side of the mounting plate 300. One end of the second wheel shaft 3022 is connected to the movable plate 3021, and the other end passes through the mounting plate 300 and is connected to a tensioning wheel 3023 located on the B side of the mounting plate 300. The tensioning wheel assembly 302 is used for controlling the tension of the filter paper tape 309. The linear guide rail 303 provides guidance for the movement of the tensioning wheel assembly 302. The third groove-shaped optocoupler 304 and the fourth groove-shaped optocoupler 305 are both fixed on the mounting plate 300 located below the tensioning wheel assembly 302. The third groove-shaped optocoupler 304 is used for determining the limit position of the tensioning wheel assembly 302 to prevent the filter paper tape 309 from being overly curled and broken. The fourth groove-shaped optocoupler 305 is used for determining the initial position of the tensioning wheel assembly 302 to control the paper feeding wheel assembly 307 to stop feeding paper. The tension spring 306 provides a tensioning force for the tensioning wheel assembly 302. The specific structures of the paper feeding wheel assembly 307 and the paper receiving wheel assembly 308 adopt the structures of the prior art, that is, the structures of a motor, a speed reducer, a shaft and a paper winding wheel are sufficient. The paper feeding wheel assembly 301 is used for releasing a new filter paper tape 309. The paper receiving wheel assembly 308 is used for curling the used old filter paper tape 309. Figure 4 In Figure 4 , a filter paper tape pressing plate 310 is fixed on the paper winding wheel (including the paper feeding wheel and the paper receiving wheel) and is used for pressing the coiled filter paper tape 309 so that it rotates synchronously with the paper feeding wheel and the paper receiving wheel. The counting wheel 17 and the first wheel shaft, the second wheel shaft 3022 and the tensioning wheel 3023, the paper feeding wheel and the paper receiving wheel and their shafts, and the paper guiding wheel and its wheel shaft all pass through the substrate 16 and are located on one side of the substrate 16. Long strip holes are correspondingly formed on the substrate 16 to facilitate the left and right movement of the counting wheel assembly 301, the tensioning wheel assembly 302, the paper feeding wheel assembly 307, the paper receiving wheel assembly 308, and the paper guiding wheel assembly 311 under the drive of the paper feeding mechanism movement driving device 4.

[0058] As Figure 6As shown, the paper feeding mechanism moving drive device 4 includes a reduction motor 401, a coupling 402, a ball screw nut assembly 403, an encoder 404, and a fixed side plate 405. The reduction motor 401 is connected to the coupling 402, the coupling 402 is connected to the ball screw of the ball screw nut assembly 403, the encoder 404 is fixed at the end of the ball screw nut assembly 403, and the fixed side plate 405 is fixed on the substrate 16. The ball screw nut assembly 403 is used to convert the rotational motion of the shaft of the reduction motor 401 into the linear motion of the nut of the ball screw nut assembly 403. An L-shaped fixing seat 406 is installed on the nut, the L-shaped fixing seat 406 is fixedly connected to the mounting plate 300, a guide rail 160 is provided on the side surface of the substrate 16, and a slider is fixed on the mounting plate 300. The positioning surface 3001 of the slider is as Figure 5 shown. When the nut moves linearly, it can drive the mounting plate 300 to move left and right, thereby realizing the displacement of the entire paper feeding mechanism 3. The encoder 404 is used to measure the moving distance of the nut and the components fixed thereon.

[0059] The cross-sectional view of the sampling and analysis mechanism 2 is as Figure 7As shown, it further includes the analysis module fixing block 204, the downstream rectifier tube 205, and the detector paper guide roller 206. The analysis module fixing block 204 is made of aluminum alloy and is processed in an integrated manner. The relative position accuracy of the components installed thereon is guaranteed by the ultra-high processing accuracy of the machine tool. The analysis module fixing block 204 is fixed on the substrate 16. The radiation source 202 is installed on the analysis module fixing block 204. The β-ray detector 203 is also fixed on the substrate 16 through the analysis module fixing block 204. The sampling nozzle 201 is fixed in the middle of the analysis module fixing block 204. The sampling nozzle 21 can be lifted and separated from the filter paper belt 309 or lowered to press the filter paper belt 309 under the action of the sampling nozzle lifting device 5, so as to construct a highly closed airflow passage to ensure that the particles are retained on the filter paper belt 309 in the same shape as the inner hole cross section of the nozzle. The downstream rectifier tube 205 is installed directly below the sampling nozzle 201. The downstream rectifier tube 205 is fixed to the lower part of the analysis module fixed block 204 and is designed according to the principle of aerodynamics to ensure that the particles are evenly distributed on the filter paper belt 309. The detector paper guide roller 206 is fixed on both sides of the radiation source 22. The top surface height is slightly higher than the top surface of the counting wheel 17 and the paper guide roller 18, so that the filter paper belt 309 is closely attached to the top surface common tangent line of the two detector paper guide rollers 26 under the action of tension, which can ensure that the filter paper belt 309 is always consistent in the vertical direction of the space of this analysis station, and can eliminate the arched cross section formed by the filter paper belt 309 under the action of tension, thereby improving the accuracy and stability of the measurement and analysis here. The paper guide roller 18 guides the movement of the filter paper belt 309. The counting wheel 17 guides the filter paper belt 309 and cooperates with the encoder to measure and control the curling length of the filter paper belt 309.

[0060] Reference Figure 8, the sampling nozzle lifting device 5 includes a driving motor 501, a first eccentric shaft 502, a spring positioning sleeve 503, and a first rolling bearing 504. The spring positioning sleeve 503 is sleeved outside the sampling nozzle 201. The spring 505 inside the spring positioning sleeve 503 is a cylindrical helical compression spring. The spring 505 is sleeved outside the sampling nozzle 201. The body of the spring positioning sleeve 503 is divided into upper and lower parts. The spring 505 is clamped between the upper and lower parts of the body of the spring positioning sleeve 503. The lower part of the body is fixedly connected to the sampling nozzle 201 by screws, and the upper part of the body is fixed. When the spring 505 is compressed, the lower part of the body of the spring positioning sleeve 503 can drive the sampling nozzle 201 to move upward. When the spring 505 resets, it can push the lower part of the body of the spring positioning sleeve 503 to drive the sampling nozzle 201 to move downward. The power end of the first eccentric shaft 502 is connected to the driving motor 501, and the working end of the first eccentric shaft 502 is connected to the first rolling bearing 504. The lower part of the body of the spring positioning sleeve 503 has a protruding edge, and the lower edge of this edge presses tightly against the outer ring of the first rolling bearing 504 under the elastic force of the spring 505. When the vertical movement component of the working end of the first eccentric shaft 502 driven by the driving motor 1 is upward, the first rolling bearing 504 compresses the spring 505 in the spring positioning sleeve 503 and drives the sampling nozzle 201 to move upward; when the vertical movement component of the working end of the first eccentric shaft 502 driven by the driving motor 501 is downward, the spring 505 in the spring positioning sleeve 503 resets and presses down the first rolling bearing 504 to drive the sampling nozzle 201 to move downward.

[0061] The sampling nozzle lifting device 5 further includes a first code disk 506 and a housing 507. The first code disk 506 is sleeved on the first eccentric shaft 502. The housing 507 covers the outside of part of the first eccentric shaft 502 and the first code disk 506. The driving motor 501 is fixed on one side of the housing 507. The motor shaft of the driving motor 501 passes through the housing 507 and enters the inside of the housing 507, and is connected to the first eccentric shaft 502 through a coupling 512.

[0062] The sampling nozzle lifting device 5 further includes a fifth groove-shaped optocoupler 508. The fifth groove-shaped optocoupler 508 is fixed on the housing 507, facing the first code disk 506. The fifth groove-shaped optocoupler 508 can detect the pulse signal of the first code disk 506, so as to determine the current position of the sampling nozzle 201 and feedback it to the control system.

[0063] The power end of the first eccentric shaft 502 passes through the substrate 16 and is connected to the substrate 16 through a bearing seat 513 and a bearing 514.

[0064] An analysis module fixing block 204 is fixedly installed on the substrate 16. The analysis module fixing block 204 is also divided into upper and lower parts. The assembly position of the spring positioning sleeve 503 is located between the upper and lower parts of the analysis module fixing block 204. Among them, the lower part of the analysis module fixing block 204 has a part for placing the filter paper strip 309. The sampling nozzle 201 is sequentially inserted into the upper part of the analysis module fixing block 204 and the lower part of the analysis module fixing block 204, and is connected to the analysis module fixing block 204 through a self-lubricating bushing 509. When the sampling nozzle 201 moves downward, it can tightly press the filter paper strip 309 to achieve the sampling purpose. When the sampling nozzle 201 moves upward and disengages from the analysis module fixing block 204, the filter paper strip 309 can be taken away for detection.

[0065] A nozzle sealing sleeve 510 is sleeved on the upper end of the sampling nozzle 201. A sealing ring 511 is provided between the sampling nozzle 201 and the nozzle sealing sleeve 510. As a preferred implementation of this embodiment, the first rolling bearing 504 of this embodiment adopts a deep groove ball bearing.

[0066] Refer to Figure 9-11 , the automatic calibration device 6 includes a standard diaphragm assembly 601, a dial 602, a dial central shaft 603, a torsion spring 604, a driving device 605, a second eccentric shaft 606 and a second rolling bearing 607. The driving device 605 is connected to the second eccentric shaft 606. The driving device 605 of this embodiment adopts a reduction motor, and the reduction motor shaft is directly fixedly connected to the second eccentric shaft 606. The working end of the second eccentric shaft 606 is connected to the second rolling bearing 607. The second rolling bearing 607 of this embodiment adopts a deep groove ball bearing. The working end of the dial central shaft 603 is connected to the dial 602, and the other end of the dial central shaft 603 is connected to the torsion spring 604. The torsion spring 604 is fixed to the end of the dial central shaft 603 by two nuts. The dial 603 is pressed against the outer ring of the second rolling bearing 607 under the torsional force of the torsion spring 604. When the working end of the second eccentric shaft 606 moves in the positive direction of the coordinate in the Y-axis movement component under the drive of the driving device 605, the end of the dial 602 is pushed to retract the standard diaphragm 6011 in the standard diaphragm assembly 601; when the working end of the second eccentric shaft 606 moves in the negative direction of the coordinate in the Y-axis movement component under the drive of the driving device 605, the end of the dial 602 pulls the standard diaphragm 6011 back into the standard diaphragm assembly 601 under the torsional force of the torsion spring 604.

[0067] The automatic calibration device 6 further includes a calibration drive device fixing seat 608, a second code disk 609, and a sixth groove optical coupler 610. The drive device 605 is fixedly connected to the calibration drive device fixing seat 608. The second eccentric shaft 606 is sleeved with the second code disk 609. The sixth groove optical coupler 610 is fixed on the calibration drive device fixing seat 608 to detect the pulse signal of the second code disk 609.

[0068] The automatic calibration device 6 further includes a second bearing 611 and a second bearing seat 612. The center shaft 603 of the dial plate passes through the calibration drive device fixing seat 608. The center shaft 603 of the dial plate above the calibration drive device fixing seat 608 is connected to the torsion spring 604. The center shaft 603 of the dial plate below the calibration drive device fixing seat 608 is connected to the second bearing seat 612 and the second bearing 611. The second bearing seat 612 is fixedly connected to the dial plate 602.

[0069] Refer to Figure 12 , the standard diaphragm assembly 601 includes a diaphragm fixing plate 6012 and a standard diaphragm chamber 6013. The standard diaphragm 6011 is fixed on the diaphragm fixing plate 6012. The diaphragm fixing plate 6012 moves in and out of the standard diaphragm chamber 6013 under the pulling and pushing of the dial plate 602. The standard diaphragm chamber 6013 is provided with an oblong groove 60130. The diaphragm fixing plate 6012 is provided with a fixing pin 60120. The diaphragm fixing plate 6012 moves in and out of the standard diaphragm chamber 6013 under the movement of the fixing pin 60120 in the oblong groove 60130 under the pulling and pushing of the dial plate 602. The standard diaphragm assembly 601 further includes a self-lubricating guide plate 6014 and a load equalizing plate 6015. The self-lubricating guide plate 6014 and the load equalizing plate 6015 are arranged in sequence on the upper part of the diaphragm fixing plate and are fastened in the standard diaphragm chamber 6013.

[0070] Refer to Figure 13-15, the external sampling pump 14 includes a housing 141, a bracket 142, a handle 143, an air duct deflector 144, a cooling fan 145, a thermostat 146, a vacuum pump 147, and an exhaust silencer 148. The housing 141 is a split structure with an upper housing and a lower housing, which are fixed by screws between the upper and lower housings and can be disassembled to facilitate the replacement of internal components. The handle 142 is fixed to the top of the housing 141, and the lower part is connected to the bracket 143. The bracket 142 is designed with a foldable structure, one end of which is hinged to the housing 141. When in use, the whole housing 141 is supported, and after use, it is folded to the bottom of the housing 141. Two lock catches 1410 are designed at the bottom of the housing 141, and two long holes 1420 are designed on the bracket 142. When the bracket 142 is stored, just rotate the lock catch 1410 and catch the lock catch 1410 on the long hole 1420, which is very convenient. The air duct deflectors 144 are fixed to two parallel sides of the housing 141. The air duct deflector 144 is a structure with an opening on the side facing the bracket 142. The side of the housing 141 where the air duct deflector 144 is installed has an air outlet. The cooling fan 145 and the thermostat 146 are fixed inside the housing 141 next to one of the air outlets. The vacuum pump 147 is fixed at the middle position inside the housing 141. The exhaust silencer 148 is connected to the vacuum pump 147. An air inlet interface 149 and an exhaust interface 140 are also installed on the housing 141, and the air inlet interface 149 and the exhaust interface 140 are respectively communicated with the vacuum pump 147.

[0071] Working principle: After the sampling and analysis cycle starts, the sampling nozzle lifting device 5 drives the sampling nozzle 201 to rise and separate from the filter paper tape 309. The first groove-shaped optocoupler 7 detects whether the paper feeding mechanism 3 is in the initial position. If not, the paper feeding mechanism moving drive device 4 drives the paper feeding mechanism 3 to return to the initial position. The fourth groove-shaped optocoupler 305 detects whether the tensioning wheel assembly 302 is in the initial position. If not, the paper feeding wheel assembly 301 rotates to release a new filter paper tape 309. The tensioning wheel assembly 302 moves towards the initial position under the action of the tensioning spring 306 as the filter paper tape 309 relaxes until it returns to the initial position, and the paper feeding wheel assembly 307 stops releasing the filter paper tape 309. At this time, the paper collecting wheel assembly 308 rotates to curl the filter paper tape 309, and the tensioning wheel assembly 302 moves towards the direction of the third groove-shaped optocoupler 304 as the filter paper tape 309 tightens, and applies a tensioning force to the filter paper tape 309 under the action of the tensioning spring 306. During the curling process of the filter paper tape 309, the counting wheel assembly 301 measures the curling length of the filter paper tape 309, and when the length reaches the program-set value, it controls the paper collecting wheel assembly 308 to stop operating. When the curling length of the filter paper tape 309 set in the program remains unchanged, since the moving trajectory and length of the tensioning wheel assembly 302 are both fixed values, the tensioning force applied to the filter paper tape 309 can be ensured to be a constant value. At this time, the position of the filter paper tape 309 at the analysis station is measured by the beta-ray detector 203, and the beta-ray intensity value I0 passing through the filter paper tape 309 at this position within the set time (T minutes) is recorded. After the measurement is completed, the paper feeding mechanism moving drive device 4 drives the paper feeding mechanism 3 to move towards the sampling position, and the moving distance is measured and controlled by the encoder. After the paper feeding mechanism 3 stops, the position of the filter paper tape 309 at the analysis station moves to the sampling station corresponding to the sampling nozzle 201. The sampling nozzle lifting device 5 drives the sampling nozzle 201 to descend, presses the filter paper tape 309 tightly, and constructs a highly airtight air flow path. The external sampling pump 14 is started, and environmental air containing particulate matter is extracted through the particulate matter cutter 9 at a constant flow rate. The particulate matter is intercepted on the filter paper tape 309, forming a "dust spot" with the same inner diameter as the sampling nozzle 201. After the external sampling pump 14 is started, the beta-ray detector 203 at the analysis station measures and records the beta-ray intensity value I1 passing through the blank filter paper tape 309 at this position within the set time (T minutes). Then the automatic calibration device 6 drives the standard diaphragm 6011 to extend and cover between the beta-ray detector 203 and the filter paper tape 309. The beta-ray detector 203 measures and records the beta-ray intensity value I2 passing through the blank filter paper tape 309 and the standard diaphragm 6011 at this position within the set time (T minutes), and the automatic calibration device 6 drives the standard diaphragm 6011 to retract.T minutes before the end of sampling, the automatic calibration device 6 drives the standard diaphragm 6011 to extend again and cover between the β-ray detector 203 and the filter paper strip 309. The β-ray detector 203 at the analysis station measures and records again the β-ray intensity value I3 passing through the blank filter paper strip 309 and the standard diaphragm 6011 at this place within the set time (T minutes), and then the automatic calibration device 6 drives the standard diaphragm 6011 to retract. After the sampling time arrives, the external sampling pump 14 stops running, the sampling nozzle lifting drive device 5 drives the sampling nozzle 201 to rise and separate from the filter paper strip 309, and the paper feeding mechanism movement drive device 4 drives the paper feeding mechanism 3 to return to its initial position. At this time, the "dust spot" returns to the analysis station, and the β-ray detector 203 measures and records the β-ray intensity value I passing through the filter paper strip 309 at this point within the set time (T minutes). x 。Bring I0 and I x into the formula to calculate the average concentration of particulate matter during the sampling and analysis period. At the same time, according to I1, I2 and I x it is possible to calculate the deviation of the concentration value caused by external factors during the sampling and analysis period, and this value is called the "compensation value". Combining and correcting the "compensation value" and the actually obtained average concentration value can obtain a more accurate "true concentration value".

[0072] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A portable high-precision ambient air particulate matter sampling and analyzing instrument, comprising a main body, wherein a substrate is arranged in the main body, and it is characterized in that: It also includes a sampling and analysis mechanism, a paper feeding mechanism, a paper feeding mechanism moving drive device, a sampling nozzle lifting device, and an automatic calibration device. The sampling and analysis mechanism is installed on the substrate. The paper feeding mechanism is arranged below the sampling and analysis mechanism. The paper feeding mechanism is connected to the paper feeding mechanism moving drive device. The sampling nozzle lifting device and the automatic calibration device are fixed on the opposite side of the substrate where the sampling and analysis mechanism is located. The paper feeding mechanism includes a mounting plate, a counting wheel assembly, two paper guiding wheel assemblies, a tensioning wheel assembly, a paper feeding wheel assembly, a paper receiving wheel assembly, a filter paper belt, and a filter paper belt pressing plate. The counting wheel assembly and one paper guiding wheel assembly are fixed at the same height on the mounting plate. The tensioning wheel assembly is fixed on the mounting plate below the counting wheel assembly and is at the same height as the other paper guiding wheel assembly on the mounting plate. The paper feeding wheel assembly and the paper receiving wheel assembly are fixed on the mounting plate below the tensioning wheel assembly and the paper guiding wheel assembly and are at the same height on the mounting plate. The filter paper belt pressing plate is fixed on the paper feeding wheel assembly and the paper receiving wheel assembly. The filter paper belt is wound around the counting wheel assembly, the paper guiding wheel assembly, the tensioning wheel assembly, the paper feeding wheel assembly, and the paper receiving wheel assembly. It also includes a first groove-shaped optocoupler and a second groove-shaped optocoupler, which are respectively fixed on the substrate above the counting wheel assembly. The tensioning wheel assembly includes a wheel shaft, a tensioning wheel, a linear guide rail, a movable plate, a tensioning spring, a third groove-shaped optocoupler, and a fourth groove-shaped optocoupler. The linear guide rail is fixed on the mounting plate. The movable plate moves left and right on the linear guide rail. The wheel shaft is connected to the movable plate. The tensioning wheel is connected to the wheel shaft. One end of the tensioning spring is connected to the movable plate, and the other end is fixedly connected to the mounting plate. The third groove-shaped optocoupler and the fourth groove-shaped optocoupler are fixed on the mounting plate below the movable plate.

2. The portable high-precision ambient air particulate matter sampling analyzer according to claim 1, wherein: The sampling and analysis mechanism includes a sampling nozzle, a radiation source, a beta-ray detector, an analysis module fixing block, a downstream rectifying tube, and a detector paper guiding roller. The radiation source and the beta-ray detector are fixed on the substrate through the analysis module fixing block. The sampling nozzle is fixed in the middle of the analysis module fixing block. The downstream rectifying tube is fixed at the lower part of the analysis module fixing plate, directly below the sampling nozzle. The detector paper guiding roller is fixed on both sides of the radiation source. The beta-ray detector is fixed directly above the radiation source.

3. The portable high-precision ambient air particulate matter sampling analyzer according to claim 1, wherein: The sampling nozzle lifting device includes a driving motor, a first eccentric shaft, a spring positioning sleeve, a first rolling bearing, and a self-lubricating bushing. The spring positioning sleeve is sleeved outside the sampling nozzle. The driving motor is connected to the first eccentric shaft. The working end of the first eccentric shaft is connected to the first rolling bearing. The lower edge of the spring positioning sleeve tightly presses the outer ring of the first rolling bearing. The sampling nozzle is connected to the analysis module fixing block through the self-lubricating bushing. The sampling nozzle lifting device also includes a first code disk, a housing, and a fifth groove-shaped optocoupler. The first code disk is sleeved on the first eccentric shaft. The housing covers part of the first eccentric shaft and the first code disk. The driving motor is fixed on one side of the housing. The fifth groove-shaped optocoupler is fixed on the housing, facing the first code disk.

4. The portable high-precision ambient air particulate matter sampling analyzer according to claim 1, wherein: The automatic calibration device includes a standard diaphragm assembly, a dial plate, a dial plate central shaft, a torsion spring, a driving device, a second eccentric shaft, and a second rolling bearing. The driving device is connected to the second eccentric shaft. The working end of the second eccentric shaft is connected to the second rolling bearing. The working end of the dial plate central shaft is connected to the dial plate. The other end of the dial plate central shaft is connected to the torsion spring. The dial plate is pressed against the outer ring of the second rolling bearing under the torsional force of the torsion spring. The automatic calibration device further includes a fixed seat for the calibration driving device, a second code disk, and a sixth groove-shaped optocoupler. The driving device is fixedly connected to the fixed seat for the calibration driving device. The second code disk is sleeved on the second eccentric shaft. The sixth groove-shaped optocoupler is fixed on the fixed seat for the calibration driving device.

5. The portable high-precision ambient air particulate matter sampling analyzer according to claim 4, characterized in that: The standard diaphragm assembly includes a diaphragm fixing plate, a standard diaphragm chamber, a self-lubricating guide plate, and a load equalizing plate. The standard diaphragm is fixed on the diaphragm fixing plate. An oblong slot is provided on the standard diaphragm chamber. A fixing pin is provided on the diaphragm fixing plate. The diaphragm fixing plate moves into and out of the standard diaphragm chamber under the pulling and pushing of the dial plate and the movement of the fixing pin in the oblong slot. The self-lubricating guide plate and the load equalizing plate are sequentially arranged on the upper part of the diaphragm fixing plate and are fastened in the standard diaphragm chamber.

6. The portable high-precision ambient air particulate matter sampling analyzer according to any one of claims 1-5, characterized in that: The outside of the main unit is further connected with a particulate matter cutter, a sampling tube, a dynamic heating tube, a temperature and humidity sensor, a tripod, an external sampling pump, a GPS, and a GPRS antenna. The particulate matter cutter is connected to the sampling tube. The dynamic heating tube is fixed outside the sampling tube. The temperature and humidity sensor, the GPS, and the GPRS antenna are fixed outside the main unit. The tripod supports the main unit below.

7. The portable high-precision ambient air particulate matter sampling analyzer according to claim 6, characterized in that: The external sampling pump includes a housing, a bracket, a handle, an air duct deflector, a cooling fan, a thermostat, a vacuum pump, and an exhaust muffler. The handle is fixed on the top of the housing, the bracket is fixed on the lower part, the air duct deflector is fixed on the side, the cooling fan, the vacuum pump, and the thermostat are fixed inside. The exhaust muffler is connected to the vacuum pump.

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