KR20190020262A - measuring apparatus for suspended particulates - Google Patents

Abstract

The present invention relates to a fine dust measuring apparatus which comprises: a light scattering measuring unit for measuring fine dust contained in the flowing air; a weight measuring unit for collecting fine dust contained in the air passing through the light scattering measuring unit; a control unit electrically connected to the light scattering measuring unit and the weight measuring unit; a pump for sucking the air so as to enable the air to flow in the light scattering measuring unit and the weight measuring unit; and a power supply unit connected to the control unit.

Description

Measuring apparatus for suspended particulates

The present invention relates to a fine dust measuring device.

Particulate matter with a diameter of 10 µm or less, in which very small invisible matter floats or scatters in the air for a long time, is called fine dust. Fine dust comes from the burning of fossil fuels such as coal and petroleum, or from emissions from manufacturing and automobile soot. Fine dust is an air pollutant that is adsorbed to the lungs through the bronchus and causes various lung diseases.

In general, dust is divided into total dust (diameter of 10 μm or more), fine dust of 10 μm or less (PM 10), and ultrafine dust of 2.5 μm or less (PM 2.5), depending on the size of the particles. Among them, fine dust is composed of ionic components such as nitrate (NO3-), ammonium (NH4 +), sulfate (SO42-), carbon compounds, and metal compounds. The World Health Organization (WHO) has designated black carbon (BC) from diesel as a first-class carcinogen. When exposed to fine dust for a long time, the immunity is rapidly lowered and can be exposed to various diseases such as cardiovascular disease, skin disease, eye disease, as well as respiratory diseases such as cold, asthma and bronchitis. In particular, ultrafine dust having a diameter of 2.5 μm or less easily penetrates deep into the bronchus and lungs in the human body and causes various diseases in the bronchus and lungs.

Meanwhile, the Ministry of Environment pointed out that in March 2017, the terminology for the fine dust used in Korea and internationally was confusing. Announced. In addition, the term encompassing both floating dust and fine dust is defined as inhalable dust, and the term superfine added to PM2.5 is intended to be used for PM1.0 and PM0.1 smaller than PM2.5.

Such fine dust suspended in the air includes a gravimetric method (small capacity air collection method, low capacity air collection method), light scattering method, beta ray measuring method and the like.

In the small capacity air collection method, dust is collected on the filter paper and the mass concentration is measured by gravimetric method (flow rate: 2 to 7 L / min). In low-capacity air collection, dust is collected on the filter paper and the mass concentration is measured by gravimetric method (flow rate: 1.2 to 1.7 m ³ / min). In the light scattering method, the amount of scattered light is measured using the principle that light is scattered when the particulate matter is irradiated with light, and the concentration of dust is obtained from the value. The beta ray measurement method continuously measures the mass concentration by using the difference between beta rays that are absorbed and extinguished when dust is collected on the filter paper, and the beta rays are transmitted through the dust collected on the filter paper.

Gravimetric method is used to measure the mass of fine dust directly with the balance. Beta-ray method is used to measure the amount of fine dust using radiation, and light scattering is performed by using the physical properties of light.

Among the three measurement methods, the weight method and the beta ray measurement method have the advantages of accurate measurement of fine dust amount and the disadvantage of real-time measurement because it is required to collect and measure fine dust directly. In addition, the light scattering method can measure in real time, but the accuracy of the measured value is inferior.

Registered Patent No. 10-0408155 (2003.11.21.)

The present invention provides a technique capable of accurately measuring the amount of fine dust in real time by simultaneously performing a light scattering method and a weight method in measuring fine dust.

The fine dust measuring apparatus according to an embodiment of the present invention, the light scattering measuring unit for measuring the fine dust contained in the flowing air, the weight measuring unit is applied to the fine dust contained in the air passing through the light scattering measuring unit, A light scattering measuring unit and a control unit electrically connected to the weight measuring unit, a pump for sucking the air so that air flows through the light scattering measuring unit and the weight measuring unit and a power supply unit connected to the control unit.

The light scattering measuring unit may include a light scattering body having a flow path formed therein, a laser diode disposed on one side of the light scattering body and generating a laser through the flow path, and a reflector disposed on the other side of the light scattering body to face the laser diode. And a detector disposed between the laser diode and the reflector to measure laser light scattered from the flow path, wherein the laser diode and the detector may be electrically connected to the controller.

The weight measuring unit is disposed in a support member having an extension space extending the flow passage, a filter unit disposed between the filter support member and the body, coupling means for connecting the support member and the body, and the coupling means. And it may include an elastic member for pressing the support member in the body direction, the air of the flow passage by the drive of the pump may be introduced into the extension space through the filter unit.

The filter unit, a filter which is located between the flow passage and the extension space may be caught by the fine dust, the fixing member for supporting the filter edge, the first sealing and the fixing disposed between the fixing member and the weight measuring unit And a second seal disposed between the member and the light scattering measuring unit, wherein the filter unit is pressed between the light scattering measuring unit and the weight measuring unit when the supporting member is pressed in a direction away from the light scattering measuring unit. Can be disengaged.

The fine dust measuring apparatus may further include an air flow module disposed between the pump and the weight measuring unit.

The fine dust measuring apparatus may further include an air inlet connected to the flow path of the light scattering measuring unit.

The air inlet, the inlet body is formed in the inlet body and the arrangement space connected to the flow passage, the first filter disposed in the placement space, the inlet space disposed in the placement space and in contact with the first filter and the inlet And a receiving body having a plurality of exhaust holes formed at a bottom thereof, a second filter contacting the receiving body and having an inlet hole formed at the center thereof, disposed in the arrangement space to support the second filter and having a plurality of holes formed therein; Is disposed in the arrangement space may include a sealing member for fixing the first filter, the receiving body, the second filter and the inlet cap and maintains the airtight between the light scattering measuring unit and the inlet cap.

The fine dust measuring apparatus may further include a case having an arrangement space in which the light scattering measuring unit, the weight measuring unit, the control unit, the pump, and the air inlet unit are located.

According to an embodiment of the present invention, the size and the number of fine dusts are measured in real time through a light scattering measuring unit, and the weight of the fine dusts is measured using a weight measuring unit while measuring the amount of fine dust in real time and the amount thereof. It can be measured accurately.

According to an embodiment of the present invention, since the light scattering measuring method and the gravimetric fine dust measuring apparatus for measuring the fine dust can be performed at the same time, it is possible to accurately measure the fine dust.

According to an embodiment of the present invention, since the fine dust information collected through the port of the controller is output, the measurer can obtain accurate information.

Figure 1 is an exploded photograph of the case of the fine dust measuring apparatus according to an embodiment of the present invention.
2 is a plan view showing the case of FIG.
3 is a perspective view of the light scattering measuring unit and the weight measuring unit of FIG.
4 is an exploded perspective view of FIG. 3.
FIG. 5 is a cross-sectional view of FIG. 2 taken along the line VV. FIG.
6 is a cross-sectional view taken along line VI-VI of FIG. 2.
7 is an enlarged view of the weight measurement unit of FIG. 6;
8 is a schematic view showing a state in which the supporting member of FIG. 7 is retracted.
9 is an exploded perspective view of the air inlet of FIG.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. Like parts are designated by like reference numerals throughout the specification.

Then, the fine dust measuring apparatus according to an embodiment of the present invention will be described with reference to FIGS.

1 is an exploded photograph of a case of a fine dust measuring apparatus according to an embodiment of the present invention, FIG. 2 is a plan view illustrating the case of FIG. 1, and FIG. 4 is an exploded perspective view of FIG. 3, FIG. 5 is a cross-sectional view of FIG. 2 taken along the line V-V, FIG. 6 is a cross-sectional view of FIG. 2 taken along the line VI-VI, and FIG. 8 is an enlarged view of a weight measuring unit, and FIG. 8 is a schematic view showing a state in which the supporting member of FIG. 7 is retracted, and FIG. 9 is an exploded perspective view of the air inlet of FIG.

1 to 9, the fine dust measuring apparatus 1 according to the present embodiment includes a case 10, an air inflow unit 20, a light scattering measurement unit 30, a weight measurement unit 40, and air. It includes a flow module 50, a pump 60, a control unit 80 and a power supply unit 90 so that the light scattering method and the gravimetric method can be performed simultaneously.

The case 10 includes a housing 11 and a cover 12 and forms an external shape of the fine dust measuring apparatus 1. The housing 11 and the cover 12 are combined to be separated into bolts, hooks and locking grooves, and the light scattering measuring unit 30, the control unit 80, and the air flow module 50 inside the housing 11. And a pump 60, and a power supply unit 90 is disposed inside the cover 12. The air inlet 20 is located outside the housing 11 and at least a part of the air inlet 20 is coupled to the inside of the housing 11. Meanwhile, the partition wall 70 is disposed between the power supply unit 90 and the air flow module 50. However, case 10 may be omitted. Meanwhile, when the case 10 is omitted, the light scattering measuring unit 30, the control unit 80, the air flow module 50, the pump 60, and the power supply unit 90 may be arranged as one module.

The air inlet 20 includes an inlet body 21, a first filter 24, a receiving body 23, a second filter 24, an inlet cap 25, and a sealing member 26. Filtering the total dust contained in the air guides the air to enter the light scattering measurement unit (30).

The inflow body 21 is formed in a cylindrical shape, and the bottom surface is in contact with the light scattering measurement unit 30, and the inside of the placement space 212 is formed in the bottom direction. An inlet 211 connected to the arrangement space 212 is formed around the upper portion of the inflow body 21. The lower periphery of the inlet body 21 is formed with a flange 213, the seating jaw 214 is formed on the upper side of the placement space 212, the seating jaw 214 is located below the inlet 211 .

The first filter 24 is positioned in the placement space 212, and the edge thereof is hung in contact with the seating jaw 214. The first filter 24 does not leave the inlet 211 by the seating jaw 214. The first filter 24 is made of metal, and a plurality of holes 221 are formed to allow air to pass therethrough.

The receiving body 23 is formed in a cylindrical shape and is disposed in the placement space 212 so that the upper surface is in contact with the first filter 24. Inside the receiving body 23 is formed a receiving space 231 which is open in the upper surface direction. A plurality of holes 232 smaller than the holes 221 of the first filter 24 are formed at the inner bottom edge of the housing body 23 at intervals. The dust larger than the hole 232 may be accommodated in the accommodation body 23.

The second filter 24 is disposed in the placement space 212 and in contact with the receiving body 23, the hole 241 through which the air passing through the hole 232 is formed in the center of the second filter 24 is formed have. The center portion of the upper surface of the second filter 24 and the center portion of the lower surface of the receiving body 23 are spaced apart from each other, and the edge portions are in contact with each other.

The inflow cap 25 is disposed in the placement space 212 and in contact with the second filter 24. Inlet cap 25 is formed with a plurality of holes 251 through which the air passing through the hole 241 passes. The hole 251 is spaced apart from the center of the inlet cap 25 is formed close to the edge. The air passing through the hole 241 is in contact with the center of the inlet cap 25 may be guided to the edge and discharged through the hole 251. The outer outer periphery of the inlet cap 25 is formed with a receiving portion 253 along the circumferential direction and the outer periphery of the lower side of the inlet cap 25 forming the receiving portion 253 and the surrounding space of the arrangement space 212 Face at intervals.

The sealing member 26 is positioned between the receiving portion 253 and the periphery of the arrangement space 212 and compressed. The sealing member 26 is fixed to prevent the inflow cap 25 from leaving the placement space 212 while blocking the air from passing between the periphery of the placement space 212 and the outer circumference of the inlet cap 25.

However, the air inlet 20 as described above may be omitted.

The light scattering measuring unit 30 includes a light scattering body 31, a laser diode 33, a reflecting unit 34, and a detecting unit 35, and fine dust included in the air introduced through the air inlet 20. Is measured by light scattering.

The light scattering body 31 is disposed in the direction X perpendicular to the lower surface of the inflow body 21, and a flow passage 311 penetrating the inside is formed at the central portion thereof. The arrangement space 212 and the flow passage 311 are connected. Air passing through the hole 251 of the inlet cap 25 may pass while flowing through the flow passage 311. The light scattering body 31 has a laser space 312 connected to the flow passage 311 in a direction X perpendicular to the center of the flow passage 311. The light scattering body 31 has an arrangement hole 313 formed in a direction Z perpendicular to the center of the laser space 312, and the arrangement hole 313 is connected to the flow passage 311 and has a lens 32. ) Is arranged.

The upper surface of the light scattering body 31 is in contact with the inner circumference of the housing 11 and is fixed with a bolt. On the other hand, the upper surface of the light scattering body 31 and the lower surface of the inlet body 21 are in contact with each other, the placement space 212 and the flow passage 311 is connected, the light scattering body 31 and the inlet body 21 is bolted Are combined. The head of the bolt is fixed to the flange (213). A bolt washer is coupled to the head of the bolt to increase the contact area with the flange 213.

The laser diode 33 is disposed on one side of the light scattering body 31 and may output a laser toward the other side of the light scattering body 31. The laser may pass through the flow passage 311.

The reflector 34 is disposed on the other side of the light scattering body 31 and may reflect the output laser toward the flow path 311. Some of the laser passing through the flow passage 311 may be scattered by hitting the fine dust contained in the air flowing through the flow passage 311.

The detector 35 is disposed on the lens 32 and detects the size and number of the fine dust through the size and the number of light generated by scattering as the laser strikes the fine dust. The detector 35 may include a lamp 351, and the lamp 351 may emit light according to whether or not fine dust is detected.

On the other hand, when the air inlet 20 is omitted, the outside air of the fine dust measuring device 1 can be introduced directly into the placement space (212).

The weight measuring unit 40 includes a support member 41, a coupling means 44, an elastic member 45, and a filter part 43, and measures the filtered fine dust by weight.

The support member 41 is provided with an extension space 411 which faces the bottom surface of the inflow body 21 at intervals and extends the flow passage 311. The extension space 411 is open to the upper surface of the support member 41. A first discharge hole 412 and a second discharge hole 413 are formed at the bottom of the extension space 411. Air in the flow passage 311 may enter the extension space 411 and be discharged through the first discharge hole 412 and the second discharge hole 413. The branch pipe 42 is disposed in the first discharge hole 412. The branch pipe 42 includes a first branch portion 421 and a second branch portion 422.

Through-holes 414 are formed at both sides of the support member 41. A step 415 is formed around the through hole 414.

The coupling means 44 is formed of a bolt and is coupled to the bottom surface of the light scattering body 31 through the through hole 414.

The elastic member 45 is disposed in the through hole 414 and is disposed between the step 415 and the head of the bolt. The elastic member 45 applies an elastic force so that the support member 41 can move in the direction of the light scattering body 31.

The filter part 43 includes a fixing member 432, a filter 431, a first sealing 433, and a second sealing 434 and is disposed between the light scattering body 31 and the supporting member 41 to flow. The fine dust included in the air introduced into the extension space 411 in the flow path 311 is caught.

The fixing member 432 is formed in the shape of a disc and has a central portion penetrated therethrough. The fixing member 432 may be made of plastic or the like.

The filter 431 is disposed at the center of the fixing member 432, and an edge portion thereof is fixed to the fixing member 432. The filter 431 may pass through the air and may be caught without passing through the fine dust contained in the air. The filter 431 may filter out ultra fine dust of 1.0 μm or less. The filter 431 may be made of fluorocarbon resin.

The first seal 433 is disposed between the fixing member 432 and the light scattering body 31 to maintain airtightness, and the second sealing 434 is disposed between the fixing member 432 and the supporting member 41. It is confidential.

The fixing member 432 is in close contact with the light scattering body 31 by the elastic force of the elastic member 45 and is fixed between the fixing member 432 and the supporting member 41, and the first sealing 433 and the second sealing are fixed. 434 may be compressed. Therefore, the light scattering body 31 and the fixing member 432 between the fixing member 432 and the support member 41 can be maintained in a close state. Air flowing into the extension space 411 through the filter 431 in the flow passage 311 is not leaked by the first seal 433 and the second seal 434 and the air is light scattering body 31 And between the fixing member 432 and the fixing member 432 and the supporting member 41 do not flow between the flow passage 311 and the extension space 411. Therefore, only air introduced through the inlet 211 may be introduced into the extension space 411.

On the other hand, when the support member 41 is pressed in a direction away from the light scattering body 31, the elastic member 45 is compressed and the support member 41 and the fixing member 432 may be spaced apart. As a result of a gap between the support member 41 and the light scattering body 31, a fixing member 432 coupled with the filter 431 may be drawn out between the support member 41 and the light scattering body 31. . The mass of the fine dust caught in the filter 431 fixed to the extracted fixing member 432 can be measured directly with a balance.

The air flow module 50 connects the weight measuring unit 40 and the pump 60. The air flow module 50 includes a first flow line 51, a second flow line 52, and a discharge line 53.

The first flow line 51 connects the first branch 421 and the inlet hole 61 of the pump 60, and the second flow line 52 connects the second discharge hole 413 and the second branch part. Connect (422). Here, the first flow line 51 passes through the first sensor 511 and the second flow line 52 passes through the second sensor 521. The first sensor 511 may detect the air flow, and the second sensor 521 may detect the air quality. In addition, the first sensor 511 and the second sensor 521 may measure air pressure, humidity, flow rate, and the like. The measurement of the first sensor 511 and the second sensor 521 may be variously changed according to design. Accordingly, the measurement of the first sensor 511 and the second sensor 521 is not limited to pressure, humidity, flow rate, air quality, air flow, and the like.

The discharge line 53 is connected to the discharge hole 62 of the pump 60. The discharge line 53 passes through the first sensor 511. The space inside the first sensor 511 is divided into a space passed by the first flow line 51 and a space passed by the discharge line 53. . That is, the second sensor 521 is partitioned into a first space (not shown) to which the first flow line 51 is connected and a second space (not shown) to which the discharge line 53 is connected.

However, the air flow module 50 may be omitted.

The pump 60 has an inlet hole 61 to which the first flow line 51 is connected, and an outlet hole 62 to which the discharge line 53 is connected, and the outside air of the case 10 is driven by the pump 60. It flows through the air inlet 20 and flows into the flow passage 311, the filter 431 and the extension space 411. Air in the extension space 411 flows along the first flow line 51 and the second flow line 52 to flow into the inflow hole 61 and be discharged to the discharge line 53 through the discharge hole 62. Can be.

On the other hand, when the air flow module 50 is omitted, the inlet hole 61 of the pump 60 is connected to the first discharge hole 412 and the second discharge hole 413 may be omitted.

The control unit 80 includes a circuit unit in which a program according to fine dust measurement is designed, and includes a laser diode 33, a detection unit 35, a first sensor 511, a second sensor 521, a pump 60, and a power supply unit 90. ) Is electrically connected to the control circuit and receives the detection signal from the laser diode 33, the detector 35, the first sensor 511, and the second sensor 521 to control the pump 60. The controller 80 may further include a port (not shown), an on-off switch (not shown), and the like that output detected data and receive information.

The power supply unit 90 is composed of a battery and supplies power to the control unit 80. Since the power supply unit 90 is formed of a battery, the fine dust measurement device 1 may have high portability.

Next, the operation of the fine dust measuring apparatus described above will be described.

The pump 60 operates when the on / off switch of the controller 80 is operated, and the laser diode 33 outputs the laser toward the flow passage 311. The external air of the fine dust measurement apparatus 1 is driven into the inlet body 21 through the inlet 211 by the driving of the pump 60, so that the first filter 24, the receiving body 23, and the second filter ( 24 and through holes 221 of the inlet caps 25. In this case, the total dust and the like contained in the air may be filtered in the inflow body 21.

Air passing through the inlet body 21 flows into the flow passage 311. At this time, the laser may be scattered to the fine dust contained in the air flowing through the flow passage (311). The detector 35 may detect the size, number, and the like of fine dust through the size, number, and the like of light generated by scattering. The detected data may be output through the output port of the controller 80 and provided to the measurer. The light scattering measuring unit 30 may measure the fine dust in real time.

Air in the flow passage 311 is introduced into the extension space 411 through the filter 431. When air passes through the filter 431, ultrafine dust of 1.0 μm or less may be filtered out. The air in the extension space 411 flows into the branch pipe 42 through the first discharge hole 412 and flows through the first flow line 51 through the first branch 421. In addition, the air in the extension space 411 flows through the second flow line 52 through the second discharge hole 413 and passes through the second branch 422 through the second branch 422 to the first flow line. Flow 51. The air of the first flow line 51 flows into the inflow hole 61 of the pump 60 via the first space of the first sensor 511 and is discharged to the discharge line 53 through the discharge hole 62. do. The air of the discharge line 53 is discharged to the outside via the second space of the first sensor 511.

The first sensor 511 and the second sensor 521 measure air pressure, humidity, and the like, and the measured data may be provided to the controller 80 to be provided to the measurer through an output port.

On the other hand, after measuring the fine dust in real time in order to accurately measure the amount of fine dust can be taken out between the support member 41 and the light scattering body (31). The housing 11 and the cover 12 are separated to take out the filter 431. And an external force is applied using the jig so that the support member 41 is separated from the light scattering body 31. The jig may press the support member 41 through the upper surface of the housing 11 and the light scattering body 31. In the direction in which the support member 41 moves away from the light scattering body 31, the milia elastic member 45 may be compressed and play may occur between the light scattering body 31 and the support member 41. Accordingly, the fixing member 432 coupled with the filter 431 may be drawn out between the supporting member 41 and the light scattering body 31. The amount of fine dust may be measured by measuring the weight of the filter 431.

As such, by measuring the size and number of the fine dust in real time through the light scattering measuring unit 30, while measuring the weight of the fine dust using the weight measuring unit 40 while measuring the fine dust in real time The amount can be measured accurately.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

1: fine dust measurement device 10: case
11: housing 12: cover
20: air inlet 21: inlet body
211: Inlet 212: Placement Space
213: flange 214: mounting jaw
22: first filter 221: hole
23: receiving body 231: receiving space
232: hole 24: second filter
241: hole 25: inlet cap
251: hole 253: receiving portion
26: sealing member 30: light scattering measuring unit
31: light scattering body 311: flow path
312: laser space 313: placement hole
32: lens 33: laser diode
34: reflector 35: detector
351: lamp 40: weight measuring unit
41: support member 411: extension space
412: first discharge hole 413: second discharge hole
414: through hole 415: step
42: branch pipe 421: first branch portion
422: second branch portion 43: filter portion
431: filter 432: fixing member
433: first seal 434: second seal
44: coupling means 45: elastic member
50: air flow module 51: the first flow line
511: first sensor 52: second flow line
521: second sensor 53: discharge line
60: pump 61: inlet hole
62: discharge hole 70: partition wall
80: control unit 90: power supply

Claims (8)

Light scattering measuring unit for measuring the fine dust contained in the flowing air,
Gravimetric unit that takes the fine dust contained in the air passing through the light scattering measuring unit,
A controller electrically connected to the light scattering measuring unit and the weight measuring unit;
A pump for sucking the air such that air flows through the light scattering measuring unit and the weight measuring unit;
A power supply unit connected to the control unit
Fine dust measuring apparatus comprising a. In claim 1,
The light scattering measuring unit,
A light scattering body in which a flow path is formed,
A laser diode disposed on one side of the light scattering body and generating a laser to the flow channel;
A reflector disposed on the other side of the light scattering body and facing the laser diode;
A detector positioned between the laser diode and the reflector to measure laser light scattered from the flow channel
Including;
The laser diode and the detector are electrically connected to the controller.
Fine dust measuring device. In claim 2,
The weight measuring unit,
A support member having an extension space extending the flow passage;
A filter unit disposed between the filter support member and the body;
Coupling means for connecting the support member and the body and
An elastic member disposed on the coupling means and urging the support member toward the body;
Including;
Air of the flow channel is driven into the extension space through the filter unit driven by the pump
Fine dust measuring device. In claim 3,
The filter unit,
A filter which is located between the flow passage and the extension space to catch the fine dust,
Fixing member for supporting the filter edge,
A first seal disposed between the fixing member and the weight measuring unit;
A second seal disposed between the fixing member and the light scattering measuring unit;
Including;
When the support member is pressed in a direction away from the light scattering measuring unit, the filter unit may be separated between the light scattering measuring unit and the weight measuring unit.
Fine dust measuring device. In claim 1,
Fine dust measuring device further comprises an air flow module disposed between the pump and the weighing unit. In claim 1,
Fine dust measuring device further comprises an air inlet connected to the flow path of the light scattering measuring unit. In claim 1,
The air inlet,
An inlet body having an inlet formed therein and having an arrangement space connected to the flow passage;
A first filter disposed in the arrangement space;
An accommodating body disposed in the arrangement space and in contact with the first filter and having an inflow space connected to the inlet, and having a plurality of exhaust holes formed at a bottom thereof;
A second filter in contact with the receiving body and having an inlet hole in the center thereof;
An inlet cap disposed in the placement space to support the second filter and having a plurality of holes;
A sealing member disposed in the arrangement space to fix the first filter, the receiving body, the second filter, and the inflow cap and to maintain airtightness between the light scattering measuring unit and the inflow cap;
Containing
Fine dust measuring device. In claim 7,
And a case having an arrangement space in which the light scattering measuring unit, the weight measuring unit, the control unit, the pump, and the air inlet unit are located.

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