Fine particle sampling device and fine particle sampling method

Abstract

To provide a recovery technique that can suppress quantitative variation in fine particle analysis caused by a collection operating environment when recovering the collection liquid stored inside a cylindrical electrode of a particle sampling device.SOLUTION: A particulate sampling method uses a cylindrical first electrode with both ends open in an axial direction and a second electrode extending in the axial direction of the first electrode and disposed within the first electrode at an interval from an inner surface of the first electrode to capture fine particles contained in air flowing through the inside. The method includes: a supply step (step S1) of supplying liquid into the first electrode and storing the liquid on a part of the inner surface in a direction around an axis of the first electrode; a liquid amount adjustment step (step S5) of adjusting a liquid amount until the liquid reaches a predetermined position on the part of the inner surface in the direction around the axis of the first electrode after the collection operation is completed; and a recovery step (step S6) of recovering the stored liquid after the liquid amount adjustment step.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present disclosure relates to a particulate sampling device and a particulate sampling method for sampling particulates.

Background Art

[0002] Conventionally, devices and methods for sampling particulates in a gas using a device that utilizes the inertia or centrifugal force of the particulates are known (see, for example, Patent Document 1). More specifically, Patent Document 1 discloses a device and a method for generating an electrostatic force by a rotating cylindrical electrode supplied with a liquid for collection (collection liquid) inside, separating an object to be collected such as particulates from the air, and collecting it in the liquid.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In conventional devices and methods for sampling particulates, when continuous operation is performed for a long time, the collection liquid vaporizes and decreases due to the flowing air. Therefore, the amount of the remaining collection liquid after the operation varies depending on the collection operation environment (temperature and humidity of the flowing air, operation time, etc.). On the other hand, when recovering the remaining collection liquid from the inside of the cylindrical electrode, a certain amount of the collection liquid remains uncollected on the surface of the cylindrical electrode or the like, and the recovery amount of the collection liquid decreases accordingly. In the analysis and evaluation of the recovered collection liquid by an analyzer, since the ratio of the particulates contained in the uncollected certain amount becomes a detection omission, even in a situation where the remaining collection liquid has collected the same number of particulates, there is a concern that the analysis results will vary depending on the amount of the remaining collection liquid, that is, the concentration of the particulates contained in the collection liquid.

[0005] The present invention has been made in view of the above-described conventional problems, and an object thereof is to provide a recovery technique capable of suppressing quantitative variations in the analysis of fine particles caused by the collection operation environment when collecting a collection liquid stored inside a cylindrical electrode in an apparatus and method for sampling fine particles.

Means for Solving the Problems

[0006] A fine particle sampling apparatus according to an aspect of the present invention is a fine particle sampling apparatus that collects fine particles contained in air flowing inside, and includes a first electrode that is cylindrical and has both ends in the axial direction thereof open, a second electrode that extends in the axial direction of the first electrode and is disposed at a distance from the inner surface of the first electrode inside the first electrode, a supply unit that supplies a liquid into the first electrode and stores the liquid in a part of the inner surface in the direction around the axis of the first electrode, a voltage application unit that applies a voltage between the first electrode and the second electrode, a drive unit that rotates the first electrode around a rotation axis that extends in the axial direction of the first electrode and passes through the inside of the first electrode, a recovery unit that recovers the stored liquid, and a control unit that controls the operation of collecting fine particles. The control unit performs control to adjust the liquid volume of the liquid after the collection operation is completed so that the liquid stored in the first electrode reaches a preset storage amount.

[0007] Further, a fine particle sampling method according to an aspect of the present invention is a fine particle sampling method that collects fine particles contained in air flowing inside, using a first electrode that is cylindrical and has both ends in the axial direction thereof open, and a second electrode that extends in the axial direction of the first electrode and is disposed at a distance from the inner surface of the first electrode inside the first electrode. The method includes a supply step of supplying a liquid into the first electrode and storing the liquid in a part of the inner surface in the direction around the axis of the first electrode, a drive step of rotating the first electrode around a rotation axis that extends in the axial direction of the first electrode and passes through the inside of the first electrode after the supply step, a voltage application step of applying a voltage between the first electrode and the second electrode, a liquid volume adjustment step of adjusting the liquid volume of the liquid until it reaches a predetermined position in a part of the inner surface in the direction around the axis of the first electrode after the collection operation is completed, and a recovery step of recovering the stored liquid after the liquid volume adjustment step. ​

Advantages of the Invention

[0008] According to the present invention, in an apparatus and method for sampling fine particles, when collecting the collection liquid stored inside the cylindrical electrode, a recovery technique capable of suppressing the quantitative variation in the analysis of fine particles caused by the collection operation environment can be provided.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0011] However, the particulate sampling device and particulate sampling method according to the present disclosure are not intended to be limited to the configurations described in the embodiments or drawings described below, and also include configurations equivalent thereto.

[0012] Each of the embodiments described below shows comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components, steps, order of steps, etc. shown in the following embodiments are merely examples and are not intended to limit the scope of the claims. Also, each figure is not necessarily drawn precisely. In each figure, substantially the same configuration is denoted by the same reference numeral, and duplicate descriptions may be omitted or simplified.

[0013] Also, hereinafter, terms indicating relationships between elements such as parallel and perpendicular, terms indicating the shapes of elements such as cylindrical shape, and numerical ranges do not represent only strict meanings, but also include substantially equivalent ranges, for example, differences of about several percent.

[0014] In the following figures, the X-axis and Y-axis are axes perpendicular to each other on the horizontal plane. The Z-axis is an axis perpendicular to the horizontal plane. In the Z-axis, the positive direction represents vertically upward, and the negative direction represents vertically downward.

[0015] (Embodiment 1) FIG. 1 is a perspective view showing the appearance of a particulate sampling device 10 according to an embodiment. FIG. 2 is a side view showing the appearance of the particulate sampling device 10 of FIG. 1. FIG. 3 is an internal view of the particulate sampling device 10 of FIG. 1 and is a sectional view taken along line III-III of FIG. 1. FIG. 4 is an end view taken along line IV-IV of FIG. 1. With reference to FIGS. 1 to 4, the particulate sampling device 10 according to the embodiment will be described.

[0016] As shown in FIGS. 1 to 4, the particulate sampling device 10 is a device for sampling particulates in a liquid. Specifically, the particulate sampling device 10 is a device that samples particulates in a liquid by collecting particulates in the gas into the liquid 68 (described later). For example, the particulates include fungi, bacteria, viruses, aerosols, and the like. The particulate sampling device 10 includes a duct 12, a first bearing seal 14, a second bearing seal 16, a first flange member 18, a second flange member 20, a first electrode 22, a second electrode 24, a voltage application unit 26, a supply unit 28, a recovery unit 30, a drive unit 32, and a liquid volume sensor 34.

[0017] The particulate sampling device 10 is configured by surrounding a rotating first electrode 22 and a second electrode 24 disposed at the center of the first electrode 22 with the duct 12, the first flange member 18, and the second flange member 20. Inside the particulate sampling device 10, a gas such as air is passed in a direction (the direction shown by the arrow A in FIG. 2) such that the particulate sampling device 10 is inserted. For example, air may be directly drawn into the particulate sampling device 10 by a pump or a fan (not shown) or the like to pass the gas through the particulate sampling device 10. Further, for example, the particulate sampling device 10 may be installed in a device having a gas flow such as an air conditioner, an air purifier, or a ventilation port, and the air may be drawn into the particulate sampling device 10 for processing. In this way, by attaching the particulate sampling device 10 to a device that generates a gas flow, it is not necessary to incorporate a pump or the like for generating a gas flow into the particulate sampling device 10, and a device that is small, quiet, and has a low pressure loss can be easily realized. As a result, it can be installed and incorporated in various places without particularly selecting a location. Note that the pump, the fan, and the device that generates a gas flow correspond to the "air blowing unit" in the claims. Hereinafter, each component of the particulate sampling device 10 will be described.

[0018] The duct 12 is cylindrical and rotatably supports the first electrode 22 inside the duct 12. The duct 12 has a main body 42, a first support portion 44, and a second support portion 46. The main body 42, the first support portion 44, and the second support portion 46 are insulating.

[0019] The main body 42 is cylindrical, and one end and the other end in the axial direction of the main body 42 are open. The first support portion 44 protrudes radially outward from one end in the axial direction of the main body 42 and is integrally formed with the main body 42. The first support portion 44 is recessed radially outward of the main body 42 and is substantially U-shaped (see FIG. 3). The first support portion 44 is annular when viewed in the axial direction of the main body 42. Inside the first support portion 44, a first bearing seal 14 is disposed. The first bearing seal 14 seals between the first support portion 44 and the first outer flange portion 58 (described later) so that gas does not leak therebetween. The first support portion 44 rotatably supports the first electrode 22 via the first bearing seal 14. The second support portion 46 protrudes radially outward from the other end in the axial direction of the main body 42 and is integrally formed with the main body 42. The second support portion 46 is recessed radially outward of the main body 42 and is substantially U-shaped (see FIG. 3). The second support portion 46 is annular when viewed in the axial direction of the main body 42. Inside the second support portion 46, a second bearing seal 16 is disposed. The second bearing seal 16 seals between the second support portion 46 and the second outer flange portion 60 (described later) so that gas does not leak therebetween. The second support portion 46 rotatably supports the first electrode 22 via the second bearing seal 16.

[0020] The first flange member 18 is cylindrical and is connected to the duct 12. The first flange member 18 has a main body 48 and a flange 50.

[0021] The main body 48 is cylindrical, and one end and the other end in the axial direction of the main body 48 are open. The flange 50 protrudes outward in the radial direction of the main body 48 from one end in the axial direction of the main body 48, and is integrally formed with the main body 48. The flange 50 is annular when viewed in the axial direction of the main body 48. The other end in the axial direction of the main body 48 is connected to one end in the axial direction of the duct 12.

[0022] The second flange member 20 is cylindrical and is connected to the duct 12. The second flange member 20 has a main body 52 and a flange 54.

[0023] The main body 52 is cylindrical, and one end and the other end in the axial direction of the main body 52 are open. One end in the axial direction of the main body 52 is connected to the other end in the axial direction of the duct 12. The flange 54 protrudes outward in the radial direction of the main body 52 from the other end in the axial direction of the main body 52, and is integrally formed with the main body 52. The flange 54 is annular when viewed in the axial direction of the main body 52.

[0024] The first electrode 22 is cylindrical, and both ends in the axial direction of the first electrode 22 are open. The first electrode 22 is connected to the ground via the second electric wire 76 (described later) and the like. The first electrode 22 has a main body 56, a first outer flange portion 58, a second outer flange portion 60, a first inner flange portion 62, and a second inner flange portion 64. For example, the main body 56, the first outer flange portion 58, the second outer flange portion 60, the first inner flange portion 62, and the second inner flange portion 64 are formed using stainless steel such as SUS (Steel Special Use Stainless).

[0025] The main body 56 is cylindrical, and one end and the other end in the axial direction of the main body 56 are open. The axial direction of the main body 56 is the direction (X-axis direction) in which the axis B of the main body 56 extends. The main body 56 has external teeth (not shown) on its outer peripheral surface that mesh with the external teeth (not shown) of a gear 86 (described later). The inner surface 66 of the main body 56 is subjected to a hydrophilic treatment. The hydrophilic treatment here is performed by surface modification by plasma treatment or by alkali treatment using potassium hydroxide (KOH). Also, for example, it is performed by coating or applying a surfactant. Further, a fixing suppression member for suppressing the adhesion of fine particles is attached to the inner surface 66 of the main body 56. For example, the fixing suppression member is a blocking agent such as skim milk, BSA (Bovine Serum Albumin), and PEG (Polyethylene Glycol).

[0026] Alternatively, at the time of sampling, a solution containing an amphiphilic polymer (a polymer having a hydrophilic group and a hydrophobic group at each end) is supplied into the electrode as a sampling solution, and for example, the electrode is rotated for about 1 minute to bring the sampling solution into contact with the entire inner surface of the electrode, thereby performing a hydrophilic treatment.

[0027] The first outer flange portion 58 protrudes outward in the radial direction of the main body 56 from one end in the axial direction of the main body 56 and is integrally formed with the main body 56. The first outer flange portion 58 is annular around the axis B of the main body 56. That is, the first outer flange portion 58 is annular when viewed from the axial direction of the main body 56. The first outer flange portion 58 is disposed inside the first bearing seal 14.

[0028] The second outer flange portion 60 protrudes outward in the radial direction of the main body 56 from the other end in the axial direction of the main body 56 and is integrally formed with the main body 56. The second outer flange portion 60 is annular around the axis B of the main body 56. That is, the second outer flange portion 60 is annular when viewed from the axial direction of the main body 56 is. The second outer flange portion 60 is disposed inside the second bearing seal 16.

[0029] The first inner flange portion 62 protrudes inward in the radial direction of the main body 56 from one end portion of the main body 56 in the axial direction, and is integrally formed with the main body 56. The first inner flange portion 62 is annular around the axis B of the main body 56. That is, the first inner flange portion 62 is annular when viewed from the axial direction of the main body 56.

[0030] The second inner flange portion 64 protrudes inward in the radial direction of the main body 56 from the other end portion of the main body 56 in the axial direction, and is integrally formed with the main body 56. The second inner flange portion 64 is annular around the axis B of the main body 56. That is, the second inner flange portion 64 is annular when viewed from the axial direction of the main body 56.

[0031] The first electrode 22 is installed in a posture where the axis B of the main body 56 is parallel to the horizontal direction. The first electrode 22 is rotatably supported around the axis B of the main body 56 (see arrow C in FIG. 4). In other words, the first electrode 22 is supported so as to be rotatable.

[0032] The first electrode 22 stores the liquid 68 on the inner surface 66 of the main body 56. Specifically, the first electrode 22 stores the liquid 68 in a part of the inner surface 66 in the direction around the axis B of the main body 56 (see arrow D in FIG. 4). The stored liquid 68 is located below the axis B of the main body 56. Also, the first electrode 22 stores the liquid 68 along the axial direction of the main body 56 in the said part of the inner surface 66. The first inner flange portion 62 holds the liquid 68 so that the liquid 68 stored in a part of the inner surface 66 of the main body 56 does not spill from one end portion of the main body 56 in the axial direction. The second inner flange portion 64 holds the liquid 68 so that the liquid 68 held in a part of the inner surface 66 of the main body 56 does not spill from the other end portion of the main body 56 in the axial direction. In this way, the first electrode 22 stores the liquid 68 in a part of the inner surface 66 of the main body 56 so that the liquid 68 does not flow out to the outside of the main body 56. Inside the main body 56, a space 69 penetrating the main body 56 in the axial direction is formed above the stored liquid 68.

[0033] The second electrode 24 is linear and extends in the axial direction of the main body 56 of the first electrode 22. The second electrode 24 passes through the inner side in the radial direction of the main body 56 of the first electrode 22 and is located inside the main body 56. That is, the second electrode 24 protrudes outward from one end of the main body 56 in the axial direction of the main body 56 and protrudes outward from the other end of the main body 56. The second electrode 24 is arranged at a distance from the inner surface 66 of the main body 56 of the first electrode 22 and is arranged near the center of the first electrode 22. The second electrode 24 is arranged in the space 69. In this embodiment, the second electrode 24 is installed in a posture where the axis of the second electrode 24 coincides with the axis B of the main body 56 of the first electrode 22. For example, the second electrode 24 is formed of tungsten or the like.

[0034] The voltage application unit 26 applies a voltage between the first electrode 22 and the second electrode 24. The voltage application unit 26 includes a first support 70, a second support 72, a first electric wire 74, and a second electric wire 76.

[0035] The first support 70 is fixed to the first flange member 18 and is located inside the first flange member 18. The first support 70 is connected to one end of the second electrode 24 in the axial direction and supports the second electrode 24. The second support 72 is fixed to the second flange member 20 and is located inside the second flange member 20. The second support 72 is connected to the other end of the second electrode 24 in the axial direction and supports the second electrode 24. The first support 70 and the second support 72 have conductivity and are electrically connected to the second electrode 24. The first electric wire 74 is electrically connected to the second electrode 24 via the second support 72. The second electric wire 76 is electrically connected to the first electrode 22 via a gear 86 or the like.

[0036] The voltage application unit 26 can pass electricity of any magnitude and waveform through the first electrode 22 and the second electrode 24 installed near the center of the first electrode 22 via the first electric wire 74 and the second electric wire 76. Thereby, the particulate sampling device 10 performs electrostatic precipitation of particulates. Note that the structure of the second electrode 24 does not have to be linear, and may be plate-shaped, needle-shaped, etc., and there is no limitation on the structure or the installation position, as long as it can form an uneven electric field. For example, the voltage application unit 26 is realized by a power supply circuit including a converter or the like. Also, for example, the voltage application unit 26 applies a DC voltage of 6 [kV].

[0037] For example, the voltage application unit 26 applies a voltage between the first electrode 22 and the second electrode 24 so that the second electrode 24 side has a higher potential than the first electrode 22 side. Thereby, an electric field is generated in the space 69 from the second electrode 24 toward the first electrode 22 (see arrow E in FIG. 3 and arrow E in FIG. 4).

[0038] Before the start of the collection operation, the supply unit 28 supplies the liquid 68 into the first electrode 22 and stores the liquid 68 in a part of the inner surface 66 in the direction around the axis B of the first electrode 22. In other words, the supply unit 28 supplies the liquid 68 into the first electrode 22 in order to store the liquid 68 in a part of the inner surface 66 in the direction around the axis B of the first electrode 22. In this way, the liquid 68 supplied by the supply unit 28 is stored on the inner surface 66 of the main body 56 of the first electrode 22. Also, after the end of the collection operation, the supply unit 28 has the role of adjusting the liquid volume of the liquid 68 by supplying new liquid 68 into the first electrode 22 so that the liquid 68 stored in the first electrode 22 becomes a preset storage amount. That is, the supply unit 28 replenishes new liquid 68 so as to reach a preset storage amount after the end of the collection operation. The supply unit 28 has a tank 78 and an injection unit 80. The supply of the liquid 68 by this supply unit 28 may be performed from the opening side of the first electrode 22 (one end side in the axial direction of the main body 42) as shown in FIG. 3, or a part of the side surface of the first electrode 22 may be opened, and the liquid may be supplied from the opening.

[0039] The liquid volume sensor 34 is a sensor that measures the liquid volume of the liquid 68 stored in a part of the inner surface 66 in the direction around the axis B of the first electrode 22 based on the position (height) of the liquid surface 68a of the liquid 68. Specifically, it is an electrode type liquid surface sensor. The liquid volume sensor 34 is adjusted to a position at a predetermined height from the inner surface 66 within the first electrode 22, and detects whether the liquid surface 68a of the liquid 68 stored in the first electrode 22 is at a position of a predetermined height or whether the liquid surface 68a of the liquid 68 is lower than the position of the predetermined height. In other words, the liquid volume sensor 34 detects whether the liquid 68 stored in the first electrode 22 is at a liquid volume that is a predetermined storage volume or whether the liquid 68 stored in the first electrode 22 is at a liquid volume less than the predetermined storage volume. Note that the liquid volume sensor 34 corresponds to the "liquid volume measurement unit" in the claims.

[0040] Details will be described later, but in this embodiment, the supply of the liquid 68 by the supply unit 28 is controlled by measuring the liquid volume of the liquid 68 by adjusting the liquid volume sensor 34 to a predetermined height so as to match the storage volume preset by the user. More specifically, after the collection operation is completed, while measuring the liquid surface 68a of the liquid 68 by the liquid volume sensor 34, the supply of the liquid 68 by the supply unit 28 is performed, and control is performed to stop the supply of the liquid 68 when the liquid surface 68a reaches a predetermined height according to the signal from the liquid volume sensor 34. Here, although FIG. 3 shows the state where the liquid volume sensor 34 is inserted into the first electrode 22, it is preferable that the liquid volume sensor 34 operates to be inserted into the first electrode 22 after the collection operation is completed. By doing so, it is possible to suppress insulation breakdown or the like due to the distance between the liquid volume sensor 34 and the second electrode 24 approaching during voltage application.

[0041] The tank 78 holds the liquid 68 for supplying into the first electrode 22. The liquid 68 held in the tank 78 is discharged from the injection part 80 by a pump (not shown) or the like and supplied into the main body 56 of the first electrode 22.

[0042] In this embodiment, the supply unit 28 supplies a liquid for the analysis of fine particles as the liquid 68. For example, the liquid for the analysis of fine particles means a liquid used for analysis, a liquid for maintaining the activity of a target substance contained in the fine particles for analysis, a liquid for imparting a label or the like to the target substance contained in the fine particles for analysis, a liquid for protecting the target substance contained in the fine particles for analysis, or any combination thereof. For example, when the target substance is an influenza virus, as the liquid 68, a liquid for preservation purposes such as physiological saline, PBS (Phosphate-Buffered Saline) buffer, EDTA (Ethylene Diamine Tetraacetic Acid) buffer, bicarbonate buffer, or a liquid for dissolving the virus, a liquid containing a substance that specifically binds to the virus and emits magnetism or fluorescence, etc. can be used. Note that the liquid 68 does not have to be a liquid for the analysis of fine particles, and for example, pure water may be used.

[0043] Note that the target substance is not limited to the influenza virus. For example, the target substance may be another virus, or a living body other than a virus (for example, bacteria). Further, the target substance does not have to be a living body, and may be an environmental pollutant or an allergen, etc.

[0044] The recovery unit 30 recovers the liquid 68 stored in a part of the inner surface 66 in the direction around the axis B of the first electrode 22. In the present embodiment, the recovery unit 30 operates to recover the entire amount of the liquid 68 stored in the first electrode 22 (the entire amount of the preset storage amount). The recovery unit 30 includes a tank 82 and an extraction unit 84. The liquid 68 stored in a part of the inner surface 66 in the direction around the axis B of the first electrode 22 is sucked from the extraction unit 84 by a pump (not shown) or the like, held in the tank 82, and recovered. In this way, the liquid 68 such as the collection liquid in which fine particles are accumulated is sucked through the extraction unit 84 and held in the tank 82. The recovery of the liquid by the recovery unit 30 may be performed from the opening side of the first electrode 22 (one end side in the axial direction of the main body 42) as shown in FIG. 3, or a part of the side surface of the first electrode 22 may be opened, and the liquid may be recovered from the opening. Further, the opening used for the supply by the supply unit 28 may be used for recovery. Further, this recovery is performed at a timing based on the collection operation time preset by the user.

[0045] The drive unit 32 rotates the first electrode 22 around a rotation axis extending in the axial direction of the main body 56 of the first electrode 22 and passing through the inside of the first electrode 22. In the present embodiment, the rotation axis coincides with the axis B of the main body 56. That is, in the present embodiment, the drive unit 32 rotates the first electrode 22 around the axis B of the main body 56 of the first electrode 22. The drive unit 32 includes a gear 86 and a motor 88 for rotating the gear 86. The gear 86 has external teeth (not shown) that mesh with the external teeth (not shown) of the first electrode 22. When the gear 86 is rotated by the motor 88 (see the arrow F in FIG. 4), the first electrode 22 rotates around the axis B in the main body 56 (see the arrow C in FIG. 4). In this way, the first electrode 22 is rotated by the gear 86 driven by the motor 88.

[0046] Note that the gas outside the fine particle sampling device 10 may pass through the inside of the second flange member 20, pass through the inside of the main body 56 of the first electrode 22, and be discharged from the first flange member 18 to the outside of the fine particle sampling device 10.

[0047] Note that a pump or a fan (not shown) corresponds to a blower unit that introduces the gas outside the fine particle sampling device 10 into the first electrode 22, and air may be drawn into the fine particle sampling device 10 in a direction (the direction indicated by arrow A in FIG. 2) that passes through the fine particle sampling device 10.

[0048] FIG. 5 is a block diagram showing the functional configuration of the fine particle sampling device 10. With reference to FIG. 5, the functional configuration of the fine particle sampling device 10 will be described.

[0049] As shown in FIG. 5, the fine particle sampling device 10 further includes a control unit 90 that includes a setting unit 91 and a calculation unit 92 therein.

[0050] The control unit 90 is electrically connected to a voltage application unit 26, a supply unit 28, a collection unit 30, a drive unit 32, and a liquid volume sensor 34. The control unit 90 controls the voltage application unit 26, the supply unit 28, the collection unit 30, the drive unit 32, and the liquid volume sensor 34. For example, the control unit 90 is implemented by a microcomputer, but may be implemented by a processor or a dedicated circuit. Further, the control unit 90 includes a setting unit 91 and a calculation unit 92 as functions.

[0051] The setting unit 91 is included in the control unit 90. The setting unit 91 sets the collection operation time, the applied voltage value in the voltage application unit 26, the collection amount in the collection unit 30, and the rotation speed in the drive unit 32, respectively. Further, a blower unit that draws air into the first electrode 22 such as a pump or a fan may be electrically connected, and the air volume may be set. For example, the setting in the setting unit 91 may be adjusted by numerical input using a touch panel or a volume knob or the like. Further, the collection amount set here is transmitted to the calculation unit 92 described later.

[0052] The calculation unit 92 is included within the control unit 90. The calculation unit 92 calculates the storage amount of the liquid 68 based on the recovery amount set in the setting unit 91, and calculates the height of the liquid amount sensor 34 so as to achieve a desired storage amount. Here, although it is stated that the calculation unit 92 calculates the storage amount of the liquid 68 based on the recovery amount set in the setting unit 91 and calculates the height of the liquid amount sensor 34 so as to achieve a desired storage amount, the relationship between the recovery amount, the storage amount, and the liquid level height may be derived and stored in advance, and the height of the liquid amount sensor 34 at the set recovery amount may be read out.

[0053] Here, the upper limit of the liquid amount that can be supplied first is set based on the liquid amount at which breakdown or the like does not surely occur due to the distance between the liquid 68 stored in the first electrode 22 and the second electrode 24 approaching when a voltage is applied between the first electrode 22 and the second electrode 24.

[0054] Next, with reference to FIGS. 6 and 7, the operation of the particulate sampling device 10 configured as described above will be described. FIG. 6 is a flowchart showing an example of the operation of the particulate sampling device 10. FIG. 7 is an explanatory diagram for explaining an example of the operation of the particulate sampling device 10, and is a diagram showing the movement of the virus until the virus is actually recovered inside the particulate sampling device 10.

[0055] Specifically, an example of the operation of the particulate sampling device 10 including the collection of the influenza virus 1, the recovery of the influenza virus 1 in the liquid, and the flow of the recovery of the liquid 68 in the present embodiment will be described. Here, an example of performing liquid collection by the particulate sampling device 10 for the purpose of recovering the influenza virus 1, which is considered to cause airborne infection, as a liquid sample that can be analyzed by a sensor or the like is shown.

[0056] As shown in FIG. 6, first, the control unit 90 controls the supply unit 28 based on the collection amount set by the user, so as to supply the liquid 68 to a preset storage amount (hereinafter, also referred to as “initial storage amount”) (step S1: supply step). For example, when the user operates an arbitrary operation button or the like, the supply unit 28 may be operated so that the liquid 68 is supplied into the main body 56 of the first electrode 22.

[0057] Next, the control unit 90 controls the drive unit 32 at the rotation speed set by the user, so that the drive unit 32 starts operating and rotates the first electrode 22 around the axis B (step S2 : drive step). For example, when the user operates an arbitrary operation button or the like, the drive unit 32 may be operated to rotate the first electrode 22. As a result, as shown in FIG. 7, the first electrode 22 rotates around the axis B at the set rotation speed while storing a part of the liquid 68 on a part of the inner surface 66 in the direction around the axis B of the main body 56 of the first electrode 22. In other words, the first electrode 22 rotates around the axis B while storing the liquid 68 below the axis B so that the liquid 68 does not flow out of the main body 56. Thereby, the inner surface 66 of the first electrode 22 sequentially contacts the stored liquid 68.

[0058] Next, when the particulate sampling device 10 operates a pump, a fan, or the like, an arbitrary air flow (see arrow A in FIG. 7) is generated. The control unit 90 controls the voltage application unit 26 to apply a voltage between the first electrode 22 and the second electrode 24 at the voltage value set by the user (step 3: voltage application step). For example, when the user operates an arbitrary operation button or the like, the voltage application unit 26 may be operated to apply a voltage between the first electrode 22 and the second electrode 24. As a result, as shown in FIG. 7, the influenza virus 1 in the gas introduced into the particulate sampling device 10 by an arbitrary air flow (see arrow A in FIG. 7) is first charged either positively or negatively by the ions 2 emitted by the discharge of the second electrode 24 to which a high voltage is applied. Here, the case where the influenza virus 1 is positively charged will be described.

[0059] The influenza virus 1 in a charged state moves like trajectory 3 by an electric field (see arrow E in Fig. 7) formed between the second electrode 24 and the first electrode 22, and is collected on the inner surface 66 of the first electrode 22. In this way, the influenza virus 1 adheres to the inner surface 66 of the first electrode 22 and is collected on the inner surface 66.

[0060] The influenza virus 1 collected on the inner surface 66 is recovered by the liquid 68 stored in the main body 56 of the first electrode 22 at an arbitrary timing as shown in Fig. 7. Specifically, the influenza virus 1 adhering to the inner surface 66 of the main body 56 of the first electrode 22 separates from the inner surface 66 by coming into contact with the stored liquid 68 and is recovered into the liquid 68. By the movement (rotation) of the first electrode 22 rotated by the motor 88 and the gear 86, the entire surface of the inner surface 66 of the first electrode 22 can be washed away by the stored liquid 68.

[0061] In the state where the inner surface 66 of the first electrode 22 is hydrophilized, before rotating the first electrode 22 around the axis B, a voltage may be applied between the first electrode 22 and the second electrode 24, and the first electrode 22 may be rotated around the axis B in a state where a voltage is applied between the first electrode 22 and the second electrode 24.

[0062] In the state where steps S2 and S3 are completed, the collection operation is performed until the collection operation time set by the user elapses. Then, after the collection operation time set by the user elapses, the rotation of the first electrode 22 and the voltage application unit to the second electrode 24 are stopped, and the collection operation is stopped.

[0063] Next, the control unit 90 inserts the liquid volume sensor 34 into the first electrode 22 to measure the liquid volume of the liquid 68 stored in the first electrode 22 (step S4: liquid volume measurement step). Specifically, as shown in FIG. 7, the control unit 90 detects whether the position of the liquid surface 68a of the liquid 68 stored in the first electrode 22 by the liquid volume sensor 34 is at a preset height position (hereinafter, also referred to as "predetermined position"). Generally, when performing continuous operation for a long time, the collected liquid vaporizes and decreases due to the flowing air, so there is also an upper limit to the supply amount (initial storage amount) of the liquid 68 supplied initially. Depending on the collection operation environment (temperature and humidity of the flowing air, operation time, etc.), the liquid volume of the collected liquid remaining after the operation ends may be less than the initially expected storage amount (or recovery amount). In the present embodiment, the initial storage amount of the liquid 68 supplied initially is set as the storage amount (predetermined storage amount) at the predetermined position. Therefore, by detecting the position (height) of the liquid surface 68a of the liquid 68 stored in the first electrode 22 by the liquid volume sensor 34, when the liquid volume of the liquid 68 stored in the first electrode 22 is less than the initially expected storage amount, such a state can be identified.

[0064] Subsequently, when the liquid volume of the liquid 68 stored in the first electrode 22 is less than the initially expected storage amount, the control unit 90 controls the supply unit 28 to newly supply the liquid 68 until the storage amount at which the liquid 68 can be detected by the liquid volume sensor 34 (step 5: liquid volume adjustment step). The storage amount here is a value set so that when the recovery unit 30 described later recovers all the liquid 68, it becomes the recovery amount preset by the user. In other words, in step S5, the supply unit 28 supplies new liquid 68 based on the liquid volume of the liquid 68 measured by the liquid volume sensor 34 (the position of the liquid surface 68a of the liquid 68) until the liquid surface 68a of the liquid 68 reaches the predetermined position after the collection operation ends.

[0065] Finally, the control unit 90 drives the recovery unit 30 to recover all the liquid 68 stored in the first electrode 22 (Step 6: Recovery Step). For example, at an arbitrary timing after the operation time of collection set by the user, the liquid 68 can be recovered to the recovery unit 30 (tank 82) through the extraction unit 84, and a liquid sample (liquid 68) containing the influenza virus 1 separated from the gas can be obtained. Also, for example, by the user operating an arbitrary operation button (not shown) or the like, the recovery unit 30 can be operated to recover the liquid 68 stored in the main body 56 of the first electrode 22. Further, the recovery amount (recovery liquid amount) at this time is controlled to be the liquid amount previously set by the user (in this embodiment, the total amount of the liquid 68 stored in the first electrode 22).

[0066] Note that when the liquid amount of the liquid 68 stored in the first electrode 22 in Step S4 is the stored amount initially expected, the control unit 90 does not perform a new supply of the liquid 68 by the supply unit 28 in Step S5, but recovers all the liquid 68 by the recovery unit 30.

[0067] Subsequently, the infection risk estimation analysis performed using the liquid 68 recovered in Step S6 will be described.

[0068] In the infection risk estimation analysis, first, a liquid 68 containing the influenza virus 1 which is a fine particle is obtained as a liquid sample from the tank 82 of the fine particle sampling device 10. For example, by the user removing the tank 82 or the like, the liquid 68 is taken out from the tank 82 to be used as a liquid sample.

[0069] Next, the taken-out liquid sample is analyzed by an analysis method capable of measuring the infectivity titer of the virus (for example, an analysis method using cells such as TCID50 evaluation) to quantify the infectivity titer of the virus contained in the liquid sample. That is, the infectivity titer of the influenza virus 1 contained in the liquid 68 recovered by the above-described fine particle sampling method (Steps S1 to S6) is quantified.

[0070] Then, based on the quantified infectious titer (infectious titer of influenza virus 1), the air flow rate of the air that has circulated inside during a certain period when voltage was applied in step S3, and the collection performance value defined by the particulate sampling method, the infectious titer per unit volume of influenza virus 1 contained in the air that has circulated inside is estimated.

[0071] Finally, the user is notified of the estimated infectious titer per unit volume of influenza virus 1. As a result, the user can grasp the situation of influenza virus 1 in the space where the particulate sampling device 10 is installed. the situation of influenza virus 1.

[0072] Also, the taken-out liquid sample may be analyzed by an analysis method capable of measuring the amount of the virus (an analysis method using PCR (Polymerase Chain Reaction) or the like), and the amount of the virus contained in the liquid sample may be quantified. That is, the amount of influenza virus 1 contained in the liquid 68 collected by the above-described particulate sampling method (steps S1 to S6) is quantified.

[0073] Then, based on the quantified virus amount (virus amount of influenza virus 1), the air flow rate of the air that has circulated inside during a certain period when voltage was applied in step S3, and the collection performance value defined by the particulate sampling method, the virus amount per unit volume of influenza virus 1 contained in the air that has circulated inside is estimated.

[0074] Finally, the user is notified of the estimated virus amount per unit volume of influenza virus 1. As a result, the user can grasp the situation of influenza virus 1 in the space where the particulate sampling device 10 is installed.

[0075] As described above, according to the particulate sampling device 10 according to Embodiment 1 and the particulate sampling method using the same, the following effects can be obtained.

[0076] (1) The particulate sampling device 10 is a particulate sampling device 10 that collects particulates contained in the air flowing inside. It is cylindrical, with both ends in the axial direction being open. There is a first electrode 22, a second electrode 24 that extends in the axial direction of the first electrode 22 and is arranged at a distance from the inner surface 66 of the first electrode 22 inside the first electrode 22, a supply unit 28 that supplies a liquid 68 into the first electrode 22 and stores the liquid 68 in a part of the inner surface 66 in the direction around the axis of the first electrode 22, a voltage application unit 26 that applies a voltage between the first electrode 22 and the second electrode 24, a drive unit 32 that rotates the first electrode 22 around a rotation axis that extends in the axial direction of the first electrode 22 and passes through the inside of the first electrode 22, a recovery unit 30 that recovers the stored liquid 68, and a control unit 90 that controls the operation of collecting particulates. The control unit 90 performs control to adjust the liquid volume of the liquid 68 after the end of the collection operation so that the liquid 68 stored in the first electrode 22 reaches a preset storage volume.

[0077] According to such a configuration, even if the liquid volume of the collected liquid remaining after the end of the operation (the liquid volume of the liquid 68 stored in the first electrode 22) varies depending on the collection operation environment (such as the temperature, humidity, and operation time of the flowing air), new liquid 68 is supplied by the supply unit 28 so that it reaches the preset storage volume after the end of the collection operation. Therefore, when recovering the collected liquid stored from the inside of the first electrode 22, the recovery amount set by the user can be stably obtained. As a result, if the collected liquid stores the same number of particulates, the concentration of the particulates contained in the collected liquid that cannot be recovered and remains constant, and fluctuations in the analysis results due to the concentration of the particulates contained in the remaining collected liquid are suppressed. As a result, fluctuations in the analysis results of the recovered liquid 68 due to the collection operation environment are suppressed. That is, it is possible to suppress the quantitative variation in the analysis of particulates caused by the collection operation environment.

[0078] As described above, in the particulate sampling device 10, when recovering the collected liquid stored inside the first electrode 22, it is possible to suppress the quantitative variation in the analysis of particulates caused by the collection operation environment.

[0079] (2) The fine particle sampling device 10 includes a liquid level sensor 34 that measures the liquid volume of the liquid 68 stored in the first electrode 22 (the position of the liquid surface 68a of the liquid 68). And, based on the liquid volume of the liquid 68 (the position of the liquid surface 68a of the liquid 68) measured by the liquid level sensor 34, the control unit 90 performs control to newly supply the liquid 68 so that the liquid 68 stored in the first electrode 22 reaches a preset storage amount. Thereby, since the liquid 68 stored in the first electrode 22 can be adjusted to a preset storage amount, when collecting the collected liquid stored from the inside of the first electrode 22, the recovery amount set by the user can be surely obtained.

[0080] (3) In the fine particle sampling device 10, the control unit 90 inserts the liquid level sensor 34 into a predetermined position inside the first electrode 22 after the collection operation is completed. Thereby, since the liquid level sensor 34 does not enter the first electrode 22 during voltage application, insulation breakdown or the like does not occur during the collection operation, and a stable collection efficiency can be obtained.

[0081] (4) In the fine particle sampling device 10, a cylindrical first electrode 22 with both ends in the axial direction open and a second electrode 24 that extends in the axial direction of the first electrode 22 and is arranged at a distance from the inner surface 66 of the first electrode 22 inside the first electrode 22 are used to collect fine particles contained in the air flowing inside. Thereby, the influenza virus 1 can be recovered from the air into the liquid 68 at a high concentration.

[0082] (5) The fine particle sampling device 10 can accumulate fine particles in the liquid 68 stored in the first electrode 22 without circulating the liquid 68, so it is easy to recover the fine particles in the liquid 68 to a high concentration. Further, the fine particle sampling device 10 is a device that does not require equipment for circulating the liquid 68 and can easily achieve miniaturization and energy saving.

[0083] (6) In the fine particle sampling device 10, the supply unit 28 supplies the liquid 68 into the first electrode 22, and the voltage application unit 26 applies a voltage between the first electrode 22 and the second electrode 24, whereby an electric field is generated between the first electrode 22 and the second electrode 24, and the fine particles contained in the gas flowing through the first electrode 22 adhere to the inner surface 66 of the first electrode 22. Then, the driving unit 32 rotates the first electrode 22, so that the inner surface 66 of the first electrode 22 sequentially contacts the liquid 68 uniformly spread and stored in a part of the inner surface 66 in the direction around the axis B of the main body 56, and the fine particles adhering to the inner surface 66 are accumulated in the liquid 68. Then, the recovery unit 30 recovers the stored liquid 68, whereby the liquid 68 in which the fine particles are accumulated is obtained. In this way, the fine particles guided into the fine particle sampling device 10 are deposited on the inner surface 66 of the first electrode 22 by electrostatic precipitation and then accumulated in the liquid 68 by the rotation of the first electrode 22, so that the fine particles can be sampled efficiently. Also, since it is not necessary to circulate the liquid 68, the liquid volume of the liquid 68 can be reduced as the initial charge volume.

[0084] (7) The fine particle sampling method is a fine particle sampling method for collecting fine particles contained in the air flowing inside, using a first electrode 22 that is cylindrical and has openings at both ends in its axial direction, and a second electrode 24 that extends in the axial direction of the first electrode 22 and is arranged at a distance from the inner surface 66 of the first electrode 22 inside the first electrode 22. The method includes a supply step (step S1) of supplying the liquid 68 into the first electrode 22 and storing the liquid 68 in a part of the inner surface 66 in the direction around the axis of the first electrode 22; a driving step (step S2) of rotating the first electrode 22 around a rotation axis that extends in the axial direction of the first electrode 22 and passes through the inside of the first electrode 22 after the supply step; a voltage application step (step S3) of applying a voltage between the first electrode 22 and the second electrode 24; a liquid volume adjustment step (step S5) of adjusting the liquid volume of the liquid 68 until it reaches a predetermined position in a part of the inner surface 66 in the direction around the axis of the first electrode 22 after the collection operation is completed; and a recovery step (step S6) of recovering the stored liquid 68 after the liquid volume adjustment step.

[0085] According to such a method, even if the amount of the collected liquid remaining after the operation (such as the temperature and humidity of the circulating air and the operation time) varies depending on the collection operation environment, a new liquid 68 is supplied by the liquid amount adjustment step (step S5) so that the preset storage amount is obtained after the end of the collection operation. Therefore, when collecting the collected liquid stored from the inside of the first electrode 22 in the recovery step (step S6), the recovery amount set by the user can be stably obtained. As a result, if the collected liquid stores the same number of fine particles, the concentration of the fine particles contained in the collected liquid that cannot be collected and remains constant in the recovery step (step S6) is always constant, and fluctuations in the analysis result due to the concentration of the fine particles contained in the remaining collected liquid are suppressed. As a result, fluctuations in the analysis result of the collected liquid 68 due to the collection operation environment are suppressed. That is, it is possible to suppress the quantification variation in the analysis of fine particles caused by the collection operation environment. )

[0086] As described above, in the fine particle sampling method, when collecting the collected liquid stored inside the first electrode 22 in the recovery step (step S6), it is possible to suppress the quantification variation in the analysis of fine particles caused by the collection operation environment.

[0087] (8) The fine particle sampling method uses a first electrode 22 that is cylindrical and has openings at both ends in its axial direction, and a second electrode 24 that extends in the axial direction of the first electrode 22 and is arranged at a distance from the inner surface 66 of the first electrode 22 inside the first electrode 22 to collect fine particles contained in the air flowing inside. Thereby, it is possible to stably collect the amount of the collected liquid (liquid 68) necessary for the analysis of fine particles. Further, by being able to uniformize with a predetermined amount of liquid 68 inside the first electrode 22 in the driving step (step S2), it is possible to obtain a high-concentration sample while suppressing variations between samplings.

[0088] (Modification 1) Next, referring to FIG. 8, the particulate sampling device 10a according to Modification 1 will be described. FIG. 8 is a cross-sectional view corresponding to FIG. 3 of the particulate sampling device 10a according to Modification 1.

[0089] The particulate sampling device 10a according to Modification 1 is different from Embodiment 1 in that a liquid level sensor 34a, which is a non-contact optical sensor, is used instead of the liquid amount sensor 34, which is an electrode type liquid level sensor. The configuration of the particulate sampling device 10a other than this and the particulate sampling method using the same are the same as those of the particulate sampling device 10 and the particulate sampling method according to Embodiment 1. Hereinafter, the content already described in Embodiment 1 will be appropriately omitted from further explanation, and the points different from Embodiment 1 will be mainly described.

[0090] As shown in FIG. 8, the particulate sampling device 10a includes a liquid amount sensor 34a for specifying the storage amount of the liquid 68 stored in the first electrode 22.

[0091] The liquid amount sensor 34a is an optical sensor that can measure the liquid amount non-contact. Specifically, as shown in FIG. 8, the liquid amount sensor 34a includes a light source unit 35 and a light receiving unit 36. Note that the liquid amount sensor 34a corresponds to the "liquid amount measuring unit" in the claims, the light source unit 35 corresponds to the "light source" in the claims, and the light receiving unit 36 corresponds to the "detector" in the claims.

[0092] The light source unit 35 is, for example, a laser light source, and is disposed inside the main body 48 of the first flange member 18 on the outside of one of both ends of the first electrode 22. The light source unit 35 irradiates the light L1 toward the interface between the liquid surface 68a of the liquid 68 stored in the first electrode 22 and the air. The light source unit 35 is connected to the control unit 90 (see FIG. 5) wirelessly or by wire, and operates in response to a signal regarding light irradiation input from the control unit 90.

[0093] The light receiving unit 36 is, for example, a photodiode, and the other of both ends of the first electrode 22 It is disposed inside the main body 52 of the second flange member 20 on the outer side. The light receiving portion 36 has a light receiving surface 36a, and the light L1 emitted from the light source portion 35 on the light receiving surface 36a becomes the light L2 that has been repeatedly reflected or refracted at the interface between the air and the liquid 68 and the inner surface 66 of the first electrode 22, and is received and detected. The light receiving surface 36a in the first modification is disposed at a position where it selectively receives light only when the liquid amount of the liquid 68 stored in the first electrode 22 reaches a preset storage amount. In other words, the light receiving surface 36a is disposed at a position where it selectively receives light only when the liquid surface 68a of the liquid 68 is at a position of a predetermined height from the inner surface 66 of the first electrode 22. That is, when the liquid surface 68a of the liquid 68 is not at a position of a predetermined height from the inner surface 66 of the first electrode 22, the light receiving surface 36a does not receive the light L2 emitted from the light source portion 35.

[0094] In this modification, the light source portion 35 and the light receiving portion 36 constituting the liquid amount sensor 34a are installed at predetermined heights so as to match the storage amount preset by the user, thereby performing supply control of the liquid 68 by the supply portion 28 (step S5 in FIG. 6). More specifically, after the collection operation is completed, while measuring the liquid surface 68a of the liquid 68 by the liquid amount sensor 34a, the supply portion 28 supplies the liquid 68, and control is performed to stop the supply of the liquid 68 when the liquid surface 68a reaches a predetermined height based on the signal from the liquid amount sensor 34a. Here, since the liquid amount sensor 34a is installed outside the cylindrical first electrode 22 that rotates during the collection operation, insulation breakdown and the like caused by the liquid amount sensor 34a approaching the second electrode 24 during voltage application can be reliably suppressed.

[0095] Next, the step of measuring the liquid amount executed in the fine particle sampling device 10a (step S4 in FIG. 6: liquid amount measurement step) will be described.

[0096] Also in Modification 1, similar to Embodiment 1, the initial storage amount of the liquid 68 supplied initially is set to a storage amount at a predetermined position (predetermined storage amount). After the operation time of collection set by the user has elapsed, when the rotation of the first electrode 22 and the voltage application unit to the second electrode 24 are stopped and the collection operation is stopped, a step of measuring the liquid amount of the liquid 68 stored in the first electrode 22 (Step S4 in FIG. 6: liquid amount measurement step) is started.

[0097] When this step is started, the light source unit 35 irradiates the light L1 toward the interface between the liquid surface 68a of the liquid 68 stored in the first electrode 22 and the air based on the signal input from the control unit 90. The light L1 emitted from the light source unit 35 is irradiated toward the interface between the liquid 68 in the first electrode 22 and the air, refracted at the interface of the liquid 68, and reflected by the inner surface 66 of the first electrode 22. The light reflected by the inner surface 66 is refracted at the interface between the liquid 68 and the air and enters the light receiving unit 36 as the light L2, and the liquid surface 68a of the liquid 68 is detected. However, when the liquid surface 68a of the liquid 68 drops due to evaporation or the like caused by the flowing air, even if the light L1 emitted from the light source unit 35 becomes the light L2, the refraction and reflection occur at a position where the liquid surface 68a of the liquid 68 is lower than the predetermined position, so that it does not enter the light receiving unit 36. Therefore, it is possible to detect a decrease in the water surface, that is, a decrease in the liquid amount, by the absence of the light detection signal at the light receiving unit 36. The control unit 90 controls the supply of the liquid 68 by the supply unit 28 based on such a signal from the light receiving unit 36. Specifically, when there is no light detection signal at the light receiving unit 36, the control unit 90 causes the supply unit 28 to execute the supply of the new liquid 68 until the light detection signal at the light receiving unit 36 is received (Step 5 in FIG. 6: liquid amount adjustment step).

[0098] Finally, when the control unit 90 receives the light detection signal at the light receiving unit 36, the control unit 90 drives the recovery unit 30 to recover all the liquid 68 stored in the first electrode 22 (Step 6 in FIG. 6: recovery step).

[0099] As described above, according to the fine particle sampling device 10a according to Modification 1 and the fine particle sampling method using the same, the following effects can be obtained.

[0100] (9) In the fine particle sampling device 10a, the liquid volume sensor 34a includes a light source unit 35 installed outside one of both ends of the first electrode 22 and a light receiving unit 36 installed outside the other end. By the light receiving unit 36 detecting the light L2 irradiated from the light source unit 35 toward the interface between the liquid 68 and the air, the liquid volume of the liquid stored in the first electrode 22 (the position of the liquid surface 68a of the liquid 68) is measured. Thereby, since the liquid 68 stored in the first electrode 22 can be adjusted to a preset storage amount, when collecting the collected liquid stored from the inside of the first electrode 22, the collection amount set by the user can be surely obtained.

[0101] (10) In the fine particle sampling device 10a, the liquid volume sensor 34a includes a light source unit 35 installed outside one of both ends of the first electrode 22 and a light receiving unit 36 installed outside the other end. Since the liquid volume sensor 34a is installed outside the cylindrical first electrode 22 that rotates during the collection operation, breakdown and the like caused by the liquid volume sensor 34a approaching the second electrode 24 during voltage application can be surely suppressed.

[0102] (11) Also in the fine particle sampling method using the fine particle sampling device 10a, the above-described effects can be enjoyed.

[0103] (Modification 2) Next, with reference to FIG. 9, the fine particle sampling device 10b according to Modification 2 will be described. FIG. 9 is a cross-sectional view corresponding to FIG. 3 of the fine particle sampling device 10b according to Modification 2.

[0104] The particulate sampling device 10a according to Modification 2 is different from the first embodiment in that a liquid volume sensor 34b having a light receiving surface 36a of the light receiving unit 36 constituting the liquid volume sensor 34a as a light receiving surface 36b that functions as a line sensor is used. The configuration of the particulate sampling device 10b other than this and the particulate sampling method using the same are the same as those of the particulate sampling device 10a and the particulate sampling method according to Modification 1. Hereinafter, the contents already described in the first embodiment and Modification 1 will be appropriately omitted from the description again, and the points different from the first embodiment and Modification 1 will be mainly described.

[0105] As shown in FIG. 9, the particulate sampling device 10b includes a liquid volume sensor 34b to specify the storage amount of the liquid 68 stored in the first electrode 22.

[0106] Similar to the liquid volume sensor 34a, the liquid volume sensor 34b is an optical sensor that can measure the liquid volume non - contact. Specifically, as shown in FIG. 9, the liquid volume sensor 34b includes a light source unit 35 and a light receiving unit 36. The liquid volume sensor 34b corresponds to the "liquid volume measurement unit" in the claims, the light source unit 35 corresponds to the "light source" in the claims, and the light receiving unit 36 corresponds to the "detector" in the claims.

[0107] The light source unit 35 is, for example, a laser light source, and is disposed inside the main body 48 of the first flange member 18 on the outer side of one of both ends of the first electrode 22. The light source unit 35 irradiates the light L1 toward the interface between the liquid surface 68a of the liquid 68 stored in the first electrode 22 and the air. The light source unit 35 is connected to the control unit 90 (see FIG. 5) wirelessly or by wire, and operates in response to a signal related to light irradiation input from the control unit 90.

[0108] The light receiving unit 36 is, for example, a photodiode array in which a plurality of photodiodes, which are light receiving elements, are arranged in a line, and is disposed inside the main body 52 of the second flange member 20 on the outer side of the other of both ends of the first electrode 22. The light receiving unit 36 has a light receiving surface 36b, and the light L1 emitted from the light source unit 35 reaches the light receiving surface 36b through the interface between the air and the liquid 68 and the first The light L2 that has been reflected or refracted repeatedly on the inner surface 66 of the electrode 22 is received and detected. The light-receiving surface 36b in the second modification has a light-receiving surface that extends linearly in the vertical direction above and below the light-receiving surface 36a in the first modification. The light-receiving surface 36b can receive the light L2 from the light source unit 35 not only when the liquid volume of the liquid 68 stored in the first electrode 22 reaches a preset stored volume, but also when it is less than or greater than the preset stored volume. That is, the liquid volume sensor 34b can measure the position (height) of the liquid surface 68a of the liquid 68 in any state, not limited to a predetermined position in the first modification.

[0109] In this modification, after the collection operation is completed, while measuring the liquid surface 68a of the liquid 68 by the liquid volume sensor 34b, the liquid 68 is supplied by the supply unit 28, and control is performed to stop the supply of the liquid 68 when the liquid surface 68a reaches a predetermined position (predetermined height) according to the signal from the liquid volume sensor 34b. Here, since the liquid volume sensor 34b is installed outside the cylindrical first electrode 22 that rotates during the collection operation, insulation breakdown and the like caused by the liquid volume sensor 34b approaching the second electrode 24 during voltage application can be reliably suppressed.

[0110] Next, the step of measuring the liquid volume executed in the fine particle sampling device 10a (step S4 in FIG. 6: liquid volume measurement step) will be described.

[0111] Similar to the first modification, also in the second modification, the initial stored volume of the liquid 68 supplied initially is set to a stored volume that becomes a predetermined position (predetermined stored volume). After the operation time of collection set by the user has elapsed, when the rotation of the first electrode 22 and the voltage application unit to the second electrode 24 are stopped and the collection operation is stopped, the step of measuring the liquid volume of the liquid 68 stored in the first electrode 22 (step S4 in FIG. 6: liquid volume measurement step) is started.

[0112] When this step is started, the light source unit 35 irradiates the light L1 toward the interface between the liquid surface 68a of the liquid 68 stored in the first electrode 22 and the air based on the signal input from the control unit 90. The light L1 emitted from the light source unit 35 is irradiated toward the interface between the liquid 68 in the first electrode 22 and the air, refracted at the interface of the liquid 68, and reflected by the inner surface 66 of the first electrode 22. The light reflected by the inner surface 66 is refracted at the interface between the liquid 68 and the air, becomes the light L2, and enters the light receiving unit 36, and the position (height) of the liquid surface 68a of the liquid 68 is detected. However, when the liquid surface 68a of the liquid 68 drops due to evaporation or the like caused by the flowing air, the position (height) of the liquid surface 68a is detected. The control unit 90 controls the supply of the liquid 68 by the supply unit 28 based on such a signal from the light receiving unit 36. Specifically, when the position (height) of the liquid surface 68a based on the signal of the light detection at the light receiving unit 36 is low, the control unit 90 causes the supply unit 28 to execute the supply of the new liquid 68 until the position (height) of the liquid surface 68a based on the signal of the light detection at the light receiving unit 36 becomes a predetermined position (height) (step 5 in FIG. 6: liquid volume adjustment step).

[0113] Finally, when the position (height) of the liquid surface 68a based on the signal of the light detection at the light receiving unit 36 becomes a predetermined position (height), the control unit 90 drives the recovery unit 30, and all the liquid 68 stored in the first electrode 22 is recovered (step 6 in FIG. 6: recovery step).

[0114] As described above, according to the fine particle sampling device 10b according to the second modification example and the fine particle sampling method using the same, the following effects can be enjoyed.

[0115] (9a) In the fine particle sampling device 10b, the liquid level sensor 34b is configured to include a light source unit 35 installed outside one of both ends of the first electrode 22 and a light receiving unit 36 installed outside the other end. By the light receiving unit 36 detecting the light L2 irradiated from the light source unit 35 toward the interface between the liquid 68 and the air, the liquid level (the position of the liquid level 68a of the liquid 68) of the liquid stored in the first electrode 22 is measured. As a result, the liquid 68 stored in the first electrode 22 can be adjusted to a preset storage amount, so that when collecting the collected liquid stored therein, the recovery amount set by the user can be surely obtained.

[0116] (10a) In the fine particle sampling device 10b, the liquid level sensor 34b is configured to include a light source unit 35 installed outside one of both ends of the first electrode 22 and a light receiving unit 36 installed outside the other end. Since the liquid level sensor 34b is installed outside the cylindrical first electrode 22 that rotates during the collection operation, insulation breakdown or the like caused by the liquid level sensor 34b approaching the second electrode 24 during voltage application can be surely suppressed.

[0117] (11a) Also in the fine particle sampling method using the fine particle sampling device 10b, the above-described effects can be enjoyed.

[0118] (12) In the fine particle sampling device 10b, a liquid level sensor 34b having a light receiving surface 36b extending linearly in the vertical direction is used. As a result, the position (height) of the liquid level 68a of the liquid 68 stored in the first electrode 22 can be measured in an arbitrary state by the liquid level sensor 34b, so that the liquid level 68a can be measured in real time, and the reduction rate of the liquid 68 in a predetermined operating environment can be calculated. As a result, the required supply amount of the liquid 68 in a predetermined operating environment can be estimated, and the user can be notified whether the supply amount of the liquid 68 by the supply unit 28 is appropriate.

[0119] (Embodiment 2) In the particulate sampling devices 10a according to Embodiment 1 to the particulate sampling devices 10a according to Modification 2, after the collection operation is completed, when the position of the liquid level 68a of the liquid 68 stored in the first electrode 22 is lower than a predetermined position (when it is less than a preset storage amount), the supply unit 28 controls to supply new liquid 68. However, in the particulate sampling device 10c according to Embodiment 2, when the position of the liquid level 68a of the liquid 68 stored in the first electrode 22 is higher than a predetermined position (when it is more than a preset storage amount), control is performed to vaporize a part of the liquid 68 by circulating air with a blower unit (not shown). The configurations of the other particulate sampling devices and the procedures of the particulate sampling method using the same are the same as those of the particulate sampling devices and the procedures of the particulate sampling method described above. Hereinafter, the contents already described in Embodiments 1 to Modification 2 will be appropriately omitted from further explanation, and the points different from Embodiments 1 to Modification 2 will be mainly described.

[0120] The particulate sampling device 10c according to Embodiment 2 has the same device configuration as the particulate sampling device 10b according to Modification 2. The liquid level sensor 34b measures the position (height) of the liquid level 68a of the liquid 68 stored in the first electrode 22, and adjusts the liquid volume of the liquid 68 so that the liquid level 68a becomes a predetermined position (predetermined height). However, in the particulate sampling device 10b according to Modification 2, after the collection operation is completed, it is assumed that the position of the liquid level 68a of the liquid 68 stored in the first electrode 22 becomes lower than a predetermined position (less than a preset storage amount). In contrast, in the particulate sampling device 10c according to Embodiment 2, after the collection operation is completed, it is assumed that the position of the liquid level 68a of the liquid 68 stored in the first electrode 22 becomes higher than a predetermined position (more than a preset storage amount).

[0121] As in Modification 2, when the initial storage amount of the liquid 68 supplied initially is set to a storage amount (predetermined storage amount) that becomes a predetermined position, since the collected liquid vaporizes and decreases due to the flowing air, the liquid amount of the collected liquid remaining after the operation ends is less than the storage amount (predetermined storage amount) that becomes a predetermined position. For this reason, depending on the collection operation environment (temperature and humidity of the flowing air, operation time, etc.), the initial storage amount may be made larger than the storage amount (predetermined storage amount) that becomes a predetermined position, or new liquid 68 may be replenished from the supply unit 28 during the collection operation. In such cases, the liquid amount of the collected liquid remaining after the operation ends may become larger than the initially expected storage amount (or recovery amount). The present embodiment is control to deal with such a situation.

[0122] Specifically, similar to Modification 2, after the operation time of collection set by the user has elapsed, when the rotation of the first electrode 22 and the voltage application unit to the second electrode 24 are stopped and the collection operation is stopped, a step of measuring the liquid amount of the liquid 68 stored in the first electrode 22 (step S4 in FIG. 6: liquid amount measurement step) is started.

[0123] When this step is started, as shown in FIG. 9, the light source unit 35 irradiates light L1 toward the interface between the liquid surface 68a of the liquid 68 stored in the first electrode 22 and the air based on the signal input from the control unit 90. The light L1 emitted from the light source unit 35 is irradiated toward the interface between the liquid 68 and the air in the first electrode 22, refracted at the interface of the liquid 68, and reflected by the inner surface 66 of the first electrode 22. The light reflected by the inner surface 66 is refracted at the interface between the liquid 68 and the air, becomes light L2, and enters the light receiving unit 36, and the position (height) of the liquid surface 68a of the liquid 68 is detected. At this time, if the liquid surface 68a of the liquid 68 has risen above the position (height) of the liquid surface 68a with respect to the recovery amount set by the user due to the initial supply amount of the liquid 68 by the supply unit 28 or the replenishment of the new liquid 68, the position (height) of the liquid surface 68a is detected. Based on such a signal from the light receiving unit 36, the control unit 90 operates a pump, a fan, or the like to generate an arbitrary air flow (see arrow A in FIG. 9). As a result, moisture volatilizes (vaporizes) from the air flowing from the liquid 68 stored in the first electrode 22, and as a result, the liquid volume of the liquid 68 decreases. Specifically, when the position (height) of the liquid surface 68a based on the light detection signal at the light receiving unit 36 is high, the control unit 90 operates a pump, a fan, or the like until the position (height) of the liquid surface 68a based on the light detection signal at the light receiving unit 36 reaches a predetermined position (height), and promotes the volatilization (vaporization) of moisture from the liquid 68 into the flowing air (Step 5 in FIG. 6: liquid volume adjustment step). That is, in the present embodiment, in Step 5 of FIG. 6, the liquid volume (position of the liquid surface 68a) of the liquid 68 is adjusted so that the liquid 68 reaches a preset storage amount by circulating air into the first electrode 22 from the outside and volatilizing (vaporizing) a part of the liquid 68.

[0124] Finally, when the position (height) of the liquid surface 68a based on the light detection signal at the light receiving unit 36 reaches a predetermined position (height), the control unit 90 drives the recovery unit 30 to recover all of the liquid 68 stored in the first electrode 22 (Step 6 in FIG. 6: recovery step).

[0125] As described above, according to the particle sampling device 10c according to the second embodiment and the particle sampling method using the same, the following effects can be obtained.

[0126] (13) The particulate sampling device 10c includes a liquid quantity sensor 34b that measures the amount of the liquid 68 stored in the first electrode 22. The control unit 90 performs control to volatilize a part of the liquid 68 after the collection operation is completed based on the amount of the liquid 68 (the position of the liquid surface 68a of the liquid 68) measured by the liquid quantity sensor 34b so that the amount of the liquid 68 stored in the first electrode 22 becomes a preset amount. More specifically, the liquid quantity sensor 34b includes a light source unit 35 installed on the outside of one of both ends of the first electrode 22 and a light receiving unit 36 ​​installed on the outside of the other end, and the light receiving unit 36 ​​detects light L1 (reflected and refracted light L2) irradiated from the light source unit 35 toward the interface between the liquid 68 and the air, thereby measuring the amount of the liquid 68 stored in the first electrode 22 (the position of the liquid surface 68a of the liquid 68).

[0127] According to this configuration, the liquid 68 stored in the first electrode 22 can be adjusted to a preset amount, so that when collecting the collected liquid stored inside the first electrode 22, the amount of collection set by the user can be reliably obtained.

[0128] (14) The particulate sampling device 10c includes an air blower (such as a pump or a fan) that blows air through the first electrode 22. The control unit 90 controls the liquid stored in the first electrode 22. In order to make the volume of liquid 68 in the first electrode 22 reach a preset volume, the blower is operated after the collection operation is completed to control the volatilization of a portion of the liquid 68. This can promote the volatilization (evaporation) of moisture from the liquid surface 68a of the liquid 68 stored in the first electrode 22 to the air flowing through the cylindrical first electrode 22. As a result, the volume of the liquid 68 can be efficiently reduced until the position (height) of the liquid surface 68a of the liquid 68 reaches a predetermined position (height).

[0129] At this time, in the voltage application state during the collection operation, since dielectric breakdown or the like would occur, it is not possible to set the air volume and the rotation speed of the first electrode 22, so that the evaporation of the liquid 68 can be further promoted by driving at the air volume and the rotation speed of the first electrode 22 that could not be set.

[0130] (15) In the fine particle sampling device 10c, a liquid level sensor 34b having a light receiving surface 36b that spreads linearly in the vertical direction is used. As a result, the position (height) of the liquid surface 68a of the liquid 68 stored in the first electrode 22 can be measured in an arbitrary state by the liquid level sensor 34b, so that the liquid surface 68a can be measured in real time, and the reduction rate of the liquid 68 in a predetermined operating environment can be calculated. As a result, the required supply amount of the liquid 68 in a predetermined operating environment can be estimated, and it is possible to notify the user whether the supply amount of the liquid 68 by the supply unit 28 is appropriate.

[0131] As described above, the present invention has been described based on the embodiments and modification examples. However, the present invention is not limited to the above embodiments and modification examples at all, and it can be easily inferred that various improvements and modifications are possible without departing from the spirit of the present invention.

[0132] In the particulate sampling device 10b according to Modification 2, when the position (height) of the liquid surface 68a based on the light detection signal at the light receiving unit 36 is low using the liquid amount sensor 34b, the supply unit 28 is made to supply new liquid 68 until the position (height) of the liquid surface 68a based on the light detection signal at the light receiving unit 36 reaches a predetermined position (height). On the other hand, in the particulate sampling device 10c according to Embodiment 2, when the position (height) of the liquid surface 68a based on the light detection signal at the light receiving unit 36 is high using the liquid amount sensor 34b, a pump, a fan, or the like is operated until the position (height) of the liquid surface 68a based on the light detection signal at the light receiving unit 36 reaches a predetermined position (height) to promote the volatilization (vaporization) of moisture from the liquid 68 into the flowing air. For this reason, in the particulate sampling device, these two controls may be combined. Thereby, according to the position (height) of the liquid surface 68a based on the light detection signal at the light receiving unit 36, the liquid amount (position of the liquid surface 68a) of the liquid 68 stored in the first electrode 22 can be easily increased or decreased, and the position of the liquid surface 68a of the liquid 68 can be surely adjusted to a predetermined position (height).

[0133] In the particulate sampling device 10 according to Embodiment 1, the case where the main body 56 of the first electrode 22 is cylindrical has been described, but it is not limited thereto. For example, the main body of the first electrode may be an elliptical cylinder, a polygonal cylinder, or the like.

[0134] In the particulate sampling device 10 according to Embodiment 1, the case where the first electrode 22 is installed in a posture where the axis B of the main body 56 is parallel to the horizontal direction has been described, but it is not limited thereto, and the first electrode 22 may not be installed in a posture where the axis B of the main body 56 is parallel to the horizontal direction. For example, the first electrode 22 may be installed in a posture where the axis B of the main body 56 is inclined with respect to the horizontal direction, and as long as the liquid 68 can be stored in a part of the inner surface 66 in the direction around the axis B of the main body 56 so that the liquid 68 does not flow out of the main body 56. In other words, the first electrode 22 may be arranged in a posture where the liquid 68 can be stored on the inner surface 66.

[0135] In addition, in the particulate sampling device 10 according to the first embodiment, the case where the second electrode 24 is installed in a posture where the axis of the second electrode 24 coincides with the axis B of the main body 56 of the first electrode 22 has been described. However, the present invention is not limited to this. The second electrode 24 does not necessarily have to be installed in a posture where the axis of the second electrode 24 coincides with the axis B of the main body 56 of the first electrode 22. For example, the second electrode 24 may be installed in a posture where the axis of the second electrode 24 is inclined with respect to the axis B of the main body 56, and it is sufficient that the second electrode 24 extends at least in the axial direction of the main body 56 of the first electrode 22. Further, for example, the second electrode 24 may be installed in a posture where the axis of the second electrode 24 does not coincide with the axis B of the main body 56 of the first electrode 22 and the axis of the second electrode 24 is parallel to the axis B of the main body 56 of the first electrode 22.

[0136] In addition, in the particulate sampling device 10 according to the first embodiment, the case where the second electrode 24 is linear has been described. However, the present invention is not limited to this. For example, the second electrode may be plate-shaped or needle-shaped, etc.

[0137] In addition, in the particulate sampling device 10 according to the first embodiment, the case where one second electrode 24 is arranged in the first electrode 22 has been described. However, the present invention is not limited to this. For example, a plurality of second electrodes may be arranged in the first electrode.

[0138] In addition, in the particulate sampling device 10 according to the first embodiment, the case where the second electrode 24 protrudes outward from one end of the main body 56 and protrudes outward from the other end of the main body 56 has been described. However, the present invention is not limited to this. For example, the length of the second electrode 24 may be the same as the length of the main body 56, or may be shorter than the length of the main body 56.

Industrial Applicability

[0139] The present invention can be widely used in devices and methods for sampling fine particles such as aerosols from gases such as air.

Explanation of Reference Numerals

[0140] 10, 10a, 10b, 10c Particle Sampling Device 12 Duct 14 First Bearing Seal 16 Second Bearing Seal 18 First Flange Member 20 Second Flange Member 22 First Electrode 24 Second Electrode 26 Voltage Application Unit 28 Supply Unit 30 Recovery Unit 32 Driving Unit 34, 34a, 34b Liquid Quantity Sensors 35 Light Source Unit 36 Light Receiving Unit 36a, 36b Light Receiving Surfaces 42, 48, 52, 56 Main Body 44 First Support Portion 46 Second Support Portion 50, 54 Flanges 58 First Outer Collar Portion 60 Second Outer Collar Portion 62 First Inner Collar Portion 64 Second Inner Collar Portion 66 Inner Surface 68 Liquid 68a Liquid Surface 69 Space 70 First Support 72 Second Support 74 First Electric Wire 76 Second Electric Wire 78 Tank 80 Injection Port 82 Tank 84 Extraction Port 86 Gear 88 Motor 90 Control Unit 91 Setting Unit 92 Calculation Unit

Claims

1. A particulate sampling device for collecting particulates contained in air flowing inside, comprising: a first electrode that is cylindrical and has openings at both axial ends thereof; a second electrode that extends in the axial direction of the first electrode and is disposed at a distance from the inner surface of the first electrode within the first electrode; a supply unit that supplies a liquid into the first electrode and stores the liquid in a part of the inner surface in the direction around the axis of the first electrode; a voltage application unit that applies a voltage between the first electrode and the second electrode; a drive unit that rotates the first electrode around a rotation axis that extends in the axial direction of the first electrode and passes through the inside of the first electrode; a recovery unit that recovers the stored liquid; a control unit that controls the operation of collecting the particulates; and is provided with: The control unit performs control to adjust the liquid volume of the liquid after the collection operation is completed so that the liquid stored in the first electrode reaches a preset storage volume. A particulate sampling device.

2. It is provided with a liquid volume measurement unit that measures the liquid volume of the liquid stored in the first electrode, The control unit performs control to newly supply a liquid based on the liquid volume of the liquid measured by the liquid volume measurement unit so that the liquid stored in the first electrode reaches the storage volume. The particulate sampling device according to claim 1.

3. The liquid volume measurement unit is configured to have a light source installed outside one of both ends of the first electrode and a detector installed outside the other end. The detector detects the light irradiated from the light source toward the interface between the liquid and the air, thereby measuring the liquid volume of the liquid stored in the first electrode. The particulate sampling device according to claim 2.

4. It is provided with a liquid volume measurement unit that measures the liquid volume of the liquid stored in the first electrode, The control unit performs control to volatilize a part of the liquid after the collection operation is completed based on the liquid volume of the liquid measured by the liquid volume measurement unit so that the liquid stored in the first electrode reaches the storage volume. The particulate sampling device according to claim 1.

5. The liquid volume measurement unit is configured to have a light source installed outside one of both ends of the first electrode and a detector installed outside the other end. The detector detects the light irradiated from the light source toward the interface between the liquid and the air, thereby measuring the liquid volume of the liquid stored in the first electrode. The particulate sampling device according to claim 4.

6. A blower unit for circulating the air in the first electrode is provided. The control unit performs control to operate the blower unit after the collection operation ends to volatilize a part of the liquid so that the liquid stored in the first electrode reaches the storage amount. The fine particle sampling device according to claim 4.

7. A fine particle sampling method for collecting fine particles contained in air flowing inside, using a first electrode that is cylindrical and has openings at both ends in the axial direction, and a second electrode that extends in the axial direction of the first electrode and is arranged at a distance from the inner surface of the first electrode inside the first electrode. A supply step of supplying a liquid into the first electrode and storing the liquid in a part of the inner surface in the direction around the axis of the first electrode. After the supply step, a driving step of rotating the first electrode around a rotation axis that extends in the axial direction of the first electrode and passes through the inside of the first electrode. A voltage application step of applying a voltage between the first electrode and the second electrode. A liquid amount adjustment step of adjusting the liquid amount of the liquid until it reaches a predetermined position in a part of the inner surface in the direction around the axis of the first electrode after the collection operation ends. A recovery step of recovering the stored liquid after the liquid amount adjustment step. Comprising A fine particle sampling method.

8. In the liquid amount adjustment step, after the collection operation ends, the storage amount of the liquid in the first electrode is measured, and based on the measured liquid amount of the liquid, new liquid is supplied until it reaches the predetermined position. The fine particle sampling method according to claim 7.

9. In the liquid amount adjustment step, after the collection operation ends, the storage amount of the liquid in the first electrode is measured, and based on the measured storage amount of the liquid, a part of the liquid is volatilized until it reaches the predetermined position. The fine particle sampling method according to claim 7.

10. In the liquid amount adjustment step, the air is circulated into the first electrode from the outside to volatilize a part of the liquid. The fine particle sampling method according to claim 9. ​

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