JP7255150B2 - Dehumidifier and detector - Google Patents

Description

The present invention relates to dehumidifiers and detection devices.

Various studies have been conducted on the detection and analysis of chemicals by Field Asymmetric Ion Mobility Spectrometry (FAIMS) systems. The FAIMS system has an ion filter with a pair of electrodes to which an asymmetrical alternating signal is applied, and ionized chemicals flow through the ion filter and are sorted by their mobility differences. Chemical substances that have passed through the ion filter are made to collide with the ion detection electrode, and the current generated by the ion detection electrode is detected to identify the chemical substance.

According to the FAIMS system, for example, the type and amount of ppb to ppt level minute molecules contained in gas can be detected. On the other hand, if the gas contains %-order water molecules, such minute molecules are buried. Also, if the humidity of the gas fluctuates, the measured value of the molecule to be detected may fluctuate.

On the other hand, a gas analyzer provided with a dehumidifier has been proposed for the purpose of improving analysis accuracy.

However, the dehumidifiers provided in conventional gas analyzers do not provide sufficient dehumidifying performance, and cannot dehumidify to the extent desired for detecting minute molecules at the ppb to ppt level.

An object of the technology disclosed herein is to provide a dehumidifier and a detection device capable of obtaining excellent dehumidification performance.

According to one aspect of the disclosed technique, the dehumidifier includes a first dehumidifying section that dehumidifies gas, a second dehumidifying section that dehumidifies the gas dehumidified by the first dehumidifying section, and the and a release section for releasing the gas dehumidified by the second dehumidification section. The second dehumidification unit has an ion generator that generates ions from the gas dehumidified by the first dehumidification unit, and a first electrode and a second electrode that face each other. an ion filter for controlling the mobility of filtered ions; and an ion collecting electrode for attracting ions that pass through the ion filter .

According to the disclosed technique, excellent dehumidification performance can be obtained.

It is a mimetic diagram showing composition of a dehumidifier concerning a 1st embodiment. It is a sectional view showing composition of a dehumidification element provided in a 1st embodiment. FIG. 4 is a diagram showing trajectories of movement of ions in an example of an ion filter; It is a figure which shows the electric field strength dependence of the mobility of ion. It is a figure which shows an example of the electric field waveform which generate|occur|produces with an ion filter. It is a schematic diagram which shows the structure of the dehumidifier which concerns on 2nd Embodiment. It is a schematic diagram which shows the structure of the dehumidifier which concerns on 3rd Embodiment. It is a schematic diagram which shows the structure of the dehumidifier which concerns on 4th Embodiment. It is a sectional view showing the composition of the lamination dehumidification element provided in a 4th embodiment. It is a schematic diagram which shows the structure of the dehumidifier which concerns on 5th Embodiment. It is a schematic diagram which shows the structure of the dehumidifier which concerns on 6th Embodiment. It is a schematic diagram which shows the structure of the dehumidifier which concerns on 7th Embodiment. FIG. 12 is a schematic diagram showing the configuration of an ion detection device according to an eighth embodiment;

Embodiments of the present disclosure will be described below with reference to the accompanying drawings. In the present specification and drawings, constituent elements having substantially the same functional configuration may be denoted by the same reference numerals, thereby omitting redundant description.

(First embodiment)
First, the first embodiment will be described. The first embodiment relates to a dehumidifier suitable for dehumidifying sample gas supplied to the FAIMS system. FIG. 1 is a schematic diagram showing the configuration of the dehumidifier according to the first embodiment.

The dehumidifier 100 according to the first embodiment includes a first dehumidifying section 1 that dehumidifies gas, a second dehumidifying section 2 that dehumidifies the gas dehumidified by the first dehumidifying section 1, and a second and a release section 30 for releasing the gas dehumidified by the dehumidification section 2 of. The first dehumidifying section 1 has a dehumidifying element 11 having a polymer electrolyte membrane. The second dehumidifying section 2 has an ion generator 21 , an ion filter 22 , an exhaust section 23 and an ion collecting electrode 24 .

Here, the dehumidifying element 11 will be described. FIG. 2 is a cross-sectional view showing the structure of the dehumidifying element 11. As shown in FIG.

As shown in FIG. 2, the dehumidifying element 11 has a polymer electrolyte membrane 111, a porous electrode 112 provided on one surface thereof, and a porous electrode 113 provided on the other surface. The porous electrode 112 is arranged inside the housing 60 forming the gas flow path, and the porous electrode 113 is arranged outside the housing 60 . A potential higher than that of the porous electrode 113 is applied to the porous electrode 112 . For example, the porous electrode 113 is grounded, and a positive voltage is applied to the porous electrode 112 by the DC power supply 12 .

In the dehumidifying element 11 configured in this manner, water molecules contained in the gas in the flow path are absorbed by the porous electrode 112, decomposed on the surface of the polymer electrolyte membrane 111 on the porous electrode 112 side, and generated by decomposition. The resulting hydrogen ions permeate the polymer electrolyte membrane 111 . The hydrogen ions that permeate the polymer electrolyte membrane 111 combine with oxygen on the surface of the polymer electrolyte membrane 111 on the porous electrode 113 side, become water molecules, and are discharged to the outside of the housing 60 .

However, although the dehumidifying element 11 is excellent in dehumidifying performance from gases with high humidity, when the humidity becomes low, for example, when the humidity drops to about 0.1% Rh, the dehumidifying performance deteriorates, and the humidity reaches a level suitable for the FAIMS system. cannot be lowered.

Therefore, in this embodiment, the second dehumidifying section 2 dehumidifies the gas that has passed through the first dehumidifying section 1 to further reduce the humidity of the gas. As described above, the second dehumidifying section 2 has the ion generator 21 , the ion filter 22 , the discharging section 23 and the ion collecting electrode 24 .

The ion generator 21 has, for example, a planar electrode 211 and a pointed electrode 212 . A potential lower than that of the electrode 211 is applied to the electrode 212 . For example, electrode 211 is grounded and electrode 212 is applied with a negative voltage by DC power supply 25 . A high electric field is generated near the tip of the electrode 212 and the gas around the tip of the electrode 212 is ionized. For example, the ion generator 21 can ionize water molecules in the gas.

Now, the ion filter 22 will be described. FIG. 3 is a diagram showing trajectories of ion movement in an example of the ion filter 22. As shown in FIG. FIG. 4 is a diagram showing electric field intensity dependence of ion mobility. FIG. 5 is a diagram showing an example of an electric field waveform generated by an ion filter.

As shown in FIG. 3, the ion filter 22 has a first electrode 221 and a second electrode 222 facing each other and controls the mobility of passing ions. Here, an XYZ three-dimensional orthogonal coordinate system is used, the traveling direction of molecules to be analyzed is the +Z direction, and the direction in which the first electrode 221 can be seen from the second electrode 222 is the +Y direction. An asymmetric electric field is applied between the first electrode 221 and the second electrode 222 by the pulse power source 29 .

Ions move at a moving speed V represented by the following equation (1) under an electric field E environment. where K is the mobility of the ion.
V=K×E (1)

By the way, the mobility of ions depends on the electric field strength. This electric field strength dependence differs depending on the type of ion. FIG. 4 shows, as an example, the electric field intensity dependence of the mobility of three different types of ions (ions 91, 92, and 93). In FIG. 4, for the sake of clarity, the ions are normalized so that the mobilities of the ions are equal when the electric field strength is zero.

The mobilities of the three ions (ions 91, 92, and 93) are almost unchanged at low electric field strengths of 9 kV/cm or less. As the electric field strength increases from about 10 kV/cm, ion type-specific properties appear in the mobility. The mobility of ions 91 increases greatly with increasing field strength and is maximum at high positive fields (Emax). The mobility of the ions 92 hardly changes regardless of the electric field strength. The mobility of ions 93 decreases slowly. In this way, it exhibits three different characteristics. The ion filter 22 selects ions by using the difference between the mobility at low electric field strength and the mobility at high electric field strength.

FIG. 3 shows trajectories of movement of three ions (ions 91 , 92 , and 93 ) between the first electrode 221 and the second electrode 222 of the ion filter 22 . Here, for convenience, the first electrode 221 and the second electrode 222 are parallel flat plates made of a conductor.

By making the waveform of the electric field generated between the first electrode 221 and the second electrode 222 an asymmetrical electric field waveform, only arbitrary ions (ions 92 in FIG. 3) can pass through the ion filter 22. can. Although the first electrode 221 is grounded in FIG. 3 , an asymmetric voltage may be applied to the first electrode 221 .

FIG. 5 shows an example of an electric field waveform generated between the first electrode 221 and the second electrode 222. As shown in FIG. This electric field waveform alternates between a positive high electric field (Emax) and a negative low electric field (Emin). The high electric field period (t1) is shorter than the low electric field period (t2), and the ratio between t1 and t2 is 1:3 to 1:5. Thus, the electric field waveform is vertically asymmetrical. This asymmetric electric field waveform has a time-averaged electric field of zero and is set so that the following equation (2) holds.
|Emax|×t1=|Emin|×t2 (2)

That is, the area of the area 81 and the area of the area 82 in FIG. 5 are set to match.

In the following description, the value of |Emax|×t1 and the value of |Emin|×t2 are assumed to be β, as shown in the following equation (3).
|Emax|×t1=|Emin|×t2=β (3)

By the way, the speed (Vup) at which ions move in the Y-axis direction during the high electric field period (t1) is given by the following equation (4). where K(Emax) is the ion mobility at high electric field (Emax).
Vup=K(Emax)×|Emax| (4)

For example, when the |Emax| Three different. That is, as shown in FIG. 3, during the high electric field period (t1), the inclinations of the three ion trajectories are different from each other.

The displacement (yup), which is the distance that ions move in the Y-axis direction during the high electric field period (t1), is given by the following equation (5).
yup=Vup×t1 (5)

On the other hand, the velocity (Vdown) at which the ions move in the Y-axis direction during the low electric field period (t2) is given by the following equation (6). where K(Emin) is the ion mobility at low electric field (Emin).
Vdown=−K(Emin)×|Emin| (6)

For example, when the |Emin| is. That is, as shown in FIG. 3, during the low electric field period (t2), the slopes of the trajectories of the three ions are almost the same.

The displacement (ydown), which is the distance that the ions move in the Y-axis direction during the low electric field period (t2), is given by the following equation (7).
ydown=Vdown×t2 (7)

Within one period (T) of the asymmetric electric field waveform, ions move in the +Z direction, move in the +Y direction during the period (t1), and move in the -Y direction during the period (t2).

Therefore, as shown in FIG. 3, one (ion 91) that repeats a zigzag movement toward the first electrode 221, one (ion 93) that repeats a zigzag movement toward the second electrode 222, and the +Y direction. and the displacement in the -Y direction are balanced, and are classified into those that pass through the ion filter 22 (ions 92).

By the way, the average displacement (ΔyRF) of ions in the Y-axis direction in one period (T) in the asymmetric electric field waveform is expressed by the following equation (8).
ΔyRF=yup+ydown
=K(Emax)×|Emax|×t1−K(Emin)×|Emin|×t2
... (8)

The above equation (8) can be expressed as the following equation (9) using the above equation (3).
ΔyRF=β{K(Emax)−K(min)} (9)

Here, if K(Emax)-K(min) is ΔK, the above equation (9) is expressed as the following equation (10).
ΔyRF=βΔK (10)

β is a constant determined by the asymmetric electric field applied between the first electrode 221 and the second electrode 222 . Therefore, the displacement of ions in the Y-axis direction per period (T) of the asymmetric electric field waveform depends on ΔK, which is the difference between the mobility in the low electric field (Emin) and the mobility in the high electric field (Emax).

Assuming that only the carrier gas transports ions in the Z-axis direction, the displacement of the ions in the Y-axis direction (Y ) is expressed by the following equation (11). Here, tres is the average time that ions stay between the first electrode 221 and the second electrode 222 (average ion residence time).

The average ion residence time tres is represented by the following equation (12). Here, A is the cross-sectional area of the ion path in the ion filter 22, L is the length of the electrode (electrode depth) in the Z-axis direction, and Q is the volumetric flow rate of the carrier gas. V is the volume of the ion filter 22 (=A×L).

The above equation (11) can be expressed as the following equation (13) using the above equations (12) and (3). Here, D is the duty of the asymmetric electric field waveform, and D=t1/T.

The high electric field (Emax) in the asymmetric electric field waveform, the volume (V) of the ion path in the ion filter 22, the duty (D) of the asymmetric electric field waveform, and the volumetric flow rate (Q) of the carrier gas are identical for all ion species. (13), the displacement (Y) is proportional to the difference ΔK between the ion species-specific mobility at a low electric field (Emin) and at a high electric field (Emax). Recognize.

In FIG. 3, the displacement (Y) of the ions 92 is the smallest, and only the ions 92 pass through the ion filter 22 . Therefore, by changing the duty (D) so that ions generated from water molecules become ions 92 , ions generated from water molecules can pass through the ion filter 22 .

Also, the ions 91 and 93 contacting the first electrode 221 or the second electrode 222 before passing through the ion filter 22 are neutralized and become molecules. These molecules, together with non-ionized molecules, are emitted from the emission section 30 and supplied as a sample gas to a gas analyzer such as the FAIMS system, for example.

In this manner, the ion filter 22 can separate ions generated from water molecules from other ions.

The discharge section 23 has an ion collecting electrode 24 and a pump 26 . A positive voltage is applied to the ion collecting electrode 24 from a DC power supply 27 . That is, a voltage having a polarity opposite to that of ions (anions) generated from water molecules is applied. A negative voltage is applied to the housing 60 between the ion filter 22 and the ion collecting electrode 24 by the DC power supply 28 . Since the electric lines of force gather at the ion collecting electrode 24 , ions passing through the ion filter 22 , for example ions generated from water molecules, are attracted to the ion collecting electrode 24 . These ions are then discharged out of the system by the pump 26 .

According to the second dehumidifying section 2 configured in this manner, the humidity of the gas dehumidified to about 0.1% Rh by the first dehumidifying section 1 can be further reduced. For example, the humidity can be lowered to 0.01% Rh or less. Then, the dehumidified gas is supplied as a sample gas to a gas analyzer such as the FAIMS system through the release section 30 .

Thus, according to the dehumidifier 100 according to the first embodiment, the humidity of the gas supplied as the sample gas to the gas analyzer such as the FAIMS system can be significantly reduced. Moreover, since only water molecules can be removed, the molecules to be analyzed can be supplied to the gas analyzer. Therefore, the gas analyzer can perform highly accurate analysis without being affected by humidity.

Although the material of the housing 60 is not particularly limited, it is desirable to use an insulator that absorbs less water molecules, is chemically stable, and reduces ion loss. For example, polytetrafluoroethylene (PTFE) can be used. Alternatively, a metal such as stainless steel may be used. However, when a conductive material is used, it is desirable to reduce ion loss as much as possible by applying a voltage having the same polarity as ions generated from water molecules.

(Second embodiment)
Next, a second embodiment will be described. The second embodiment differs from the first embodiment in the configuration of the discharge section 23 . FIG. 6 is a schematic diagram showing the configuration of a dehumidifier according to the second embodiment.

In the dehumidifier 200 according to the second embodiment, a coolable ion collecting electrode 224 is provided instead of the ion collecting electrode 24 and the pump 26, and a drain pipe 225 is arranged below the ion collecting electrode 224. A cooling section 226 for cooling the ion collecting electrode 224 is also provided. Drain pipe 225 is an example of a waste section.

Other configurations are the same as those of the first embodiment.

In the dehumidifier 200, by cooling the ion collecting electrode 224 with the cooling device, the ions directed toward the ion collecting electrode 224 can be molecularized and condensed. The liquefied water molecules are discharged out of the system through the drain pipe 225 .

Also according to the second embodiment, the humidity of the gas supplied as the sample gas to the gas analyzer such as the FAIMS system can be significantly reduced. Moreover, since only water molecules can be removed, the molecules to be analyzed can be supplied to the gas analyzer. Therefore, the gas analyzer can perform highly accurate analysis without being affected by humidity.

(Third embodiment)
Next, a third embodiment will be described. The third embodiment differs from the first embodiment in the configuration of the discharge section 23 . FIG. 7 is a schematic diagram showing the configuration of a dehumidifier according to the third embodiment.

A dehumidifier 400 according to the third embodiment is provided with a metal mesh 31 at the entrance of the discharge section 30 . A voltage having the same polarity as the housing 60 is applied to the metal mesh 31 . That is, a negative potential is applied to the metal mesh 31 from the DC power supply 28 .

Other configurations are the same as those of the first embodiment.

The dehumidifier 400 also provides the same effects as the first embodiment. Furthermore, according to the dehumidifier 400 , it is possible to more reliably suppress the outflow of ions generated from water molecules and having passed through the ion filter 22 to the release section 30 .

(Fourth embodiment)
Next, a fourth embodiment will be described. The fourth embodiment differs from the first embodiment in the configuration of the first dehumidifying section 1 . FIG. 8 is a schematic diagram showing the configuration of a dehumidifier according to the fourth embodiment.

A dehumidifier 500 according to the fourth embodiment includes a laminated dehumidifying element 511 instead of the dehumidifying element 11 . FIG. 9 is a cross-sectional view showing the configuration of the laminated dehumidifying element 511. As shown in FIG.

As shown in FIG. 9, the laminated dehumidifying element 511 has a polymer electrolyte membrane 521, a porous electrode 522 provided on one surface thereof, and a porous electrode 523 provided on the other surface. The laminated dehumidifying element 511 further has a polymer electrolyte membrane 531, a porous electrode 532 provided on one surface thereof, and a porous electrode 533 provided on the other surface. The laminated dehumidifying element 511 further has an intermediate layer 512 provided between the porous electrodes 532 and 523 . The intermediate layer 512 is a layer containing oxygen, such as an air layer. The porous electrode 522 is arranged inside the housing 60 forming the gas flow path, and the porous electrode 533 is arranged outside the housing 60 . A potential higher than that of the porous electrodes 523 and 533 is applied to the porous electrodes 522 and 532 . For example, the porous electrodes 523 and 533 are grounded, and a positive voltage is applied to the porous electrodes 522 and 532 by the DC power supply 12 . Thus, the first dehumidifying section 1 has a laminated dehumidifying element 511 in which a plurality of dehumidifying elements are stacked.

In the dehumidification element 11, if the humidity outside the housing 60 is significantly higher than the humidity inside the housing 60, the dehumidification performance may deteriorate. For example, if the humidity outside the housing 60 is about 80% Rh, hydrogen ions may become difficult to move between the porous electrodes 112 and 113 with the polymer electrolyte membrane 111 interposed therebetween. . On the other hand, in the laminated dehumidifying element 511, the intermediate layer 512 contains oxygen, and dehumidification can be performed in two stages, so that the humidity difference in each stage can be reduced. For example, if the humidity of the intermediate layer 512 is about 10% Rh to 15% Rh, the movement of hydrogen ions between the porous electrodes 522 and 523 also increases between the porous electrodes 532 and 533. The transport of hydrogen ions between can also be maintained in good condition.

Other configurations are the same as those of the first embodiment. The number of dehumidifying elements included in the laminated dehumidifying element 511 is not limited, and may be three or more.

The dehumidifier 500 also provides the same effects as the first embodiment. Furthermore, according to the dehumidifier 500, even when the humidity outside the housing 60 is significantly higher than the humidity inside the housing 60, it is easy to maintain excellent dehumidification performance.

(Fifth embodiment)
Next, a fifth embodiment will be described. The fifth embodiment differs from the first embodiment in the configuration of the first dehumidifying section 1. FIG. FIG. 10 is a schematic diagram showing the configuration of a dehumidifier according to the fifth embodiment.

A dehumidifier 600 according to the sixth embodiment is provided with a variable DC power supply 612 instead of the DC power supply 12 . The first dehumidification section 1 also has a humidity control circuit 611 and a humidity detection section 613 . The humidity detection unit 613 is provided between the dehumidification element 11 and the ion generator 21 and detects the humidity of the gas that has passed through the dehumidification element 11 . Humidity control circuit 611 feedback-controls the voltage of variable DC power supply 612 based on the humidity detected by humidity detector 613 . For example, the humidity control circuit 611 controls the dehumidification element 11 through the voltage of the variable DC power supply 612 so that the humidity of the gas supplied to the ion generator 21 is approximately constant.

The dehumidifier 600 also provides the same effect as the first embodiment. Furthermore, according to the dehumidifier 600, even if the humidity of the gas supplied to the dehumidifier 600 fluctuates greatly, the humidity of the gas supplied to the gas analyzer as the sample gas can be stabilized. Therefore, the gas analyzer can perform highly accurate analysis without being affected by humidity fluctuations.

For example, a dew point meter, a resistance humidity sensor, a capacitance humidity sensor, or the like can be used for the humidity detection unit 613 . Among them, a capacitive humidity sensor, which is particularly excellent in detecting low humidity, is desirable.

(Sixth embodiment)
Next, a sixth embodiment will be described. The sixth embodiment differs from the fifth embodiment in the configuration of the second dehumidifying section 2 . FIG. 11 is a schematic diagram showing the configuration of a dehumidifier according to the sixth embodiment.

A dehumidifier 700 according to the sixth embodiment includes a variable DC power supply 725 instead of the DC power supply 25 . The second dehumidification section 2 also has a humidity control circuit 721 and a humidity detection section 723 . The humidity detector 723 is provided inside the discharge section 30 and detects the humidity of the gas flowing through the discharge section 30 . Humidity control circuit 721 feedback-controls the voltage of variable DC power supply 725 based on the humidity detected by humidity detector 723 . For example, the humidity control circuit 721 controls the ion filter 22 through the voltage of the variable DC power supply 725 so that the humidity of the gas supplied as the sample gas to the gas analyzer is approximately constant.

The dehumidifier 700 also provides the same effects as the fifth embodiment. Furthermore, when the ion generator 21 deteriorates, the ionization rate of water molecules may decrease. Even in such a case, the humidity of the gas flowing through the discharge section 30 can be stabilized. Therefore, the gas analyzer can perform highly accurate analysis without being affected by humidity fluctuations.

Although the configuration of the humidity detection unit 723 is not limited, for example, a polymer electrolyte membrane is provided in the humidity detection unit 723, and the characteristic that the amount of current consumed by the polymer electrolyte membrane changes according to the humidity when it electrolyzes water is utilized. A configuration in which humidity is detected by For example, a capacitance type humidity sensor or the like may be used for the humidity detection unit 723 .

(Seventh embodiment)
Next, a seventh embodiment will be described. The seventh embodiment differs from the fifth embodiment in the configuration of the second dehumidifying section 2 . FIG. 12 is a schematic diagram showing the configuration of a dehumidifier according to the seventh embodiment.

A dehumidifier 800 according to the seventh embodiment is provided with a variable DC power supply 725 instead of the DC power supply 25 . The second dehumidifying section 2 also has a humidity control circuit 821 and an ammeter 822 . Ammeter 822 measures the current flowing through ion collecting electrode 24 . Humidity control circuit 821 feedback-controls the voltage of variable DC power supply 725 based on the current measured by ammeter 822 . For example, the humidity control circuit 821 controls the voltage of the variable DC power supply 725 so that the difference between the humidity of the gas supplied to the ion generator 21 and the humidity calculated from the current flowing through the ion collecting electrode 24 is approximately constant. Control the ion filter 22 .

The dehumidifier 800 also provides the same effect as the fifth embodiment. Furthermore, the measurement result by the ammeter 822 reflects the amount of moisture dehumidified by the second dehumidifying section 2 . Therefore, the humidity of the gas flowing through the discharge section 30 can be calculated from the difference between the humidity measured by the humidity detection section 613 and the humidity calculated from the current flowing through the ion collecting electrode 24 . Therefore, even if the humidity of the gas flowing through the discharge section 30 is so low that it is difficult to detect by the humidity detection section 723 of the dehumidifier 700, the humidity of the gas flowing through the discharge section 30 can be stabilized. Therefore, the gas analyzer can perform highly accurate analysis without being affected by humidity fluctuations.

It should be noted that humidity control should preferably be based on absolute humidity. Therefore, it is desirable to measure the temperature as well as detect the humidity, calculate the absolute humidity, and control the dehumidifying element 11 and the ion filter 22 based on the absolute humidity.

(Eighth embodiment)
Next, an eighth embodiment will be described. FIG. 13 is a schematic diagram showing the configuration of an ion detection device according to the eighth embodiment.

An ion detection device 900 according to the eighth embodiment includes an ion filter 910 , an ion detection electrode (ion detection section) 920 and a dehumidifier 930 . The ion filter 910 has a first electrode 911 and a second electrode 912 facing each other and controls the mobility of ions passing therethrough. The ion filter 910 has, for example, the same configuration as the ion filter 22 and functions similarly to the ion filter 22 . Passing ions that have passed through the ion filter 910 collide with the ion detection electrode 920 . That is, passing ions contact the ion detection electrode 920 . The ion detection electrode 920 detects passing ions and outputs an electrical characteristic value corresponding to the strength of the contact. Examples of electrical characteristic values include current values, voltage values, and resistance values. The ion detection electrode 920 is an example of an output section. A dehumidifier 930 is the dehumidifier of any one of the first to seventh embodiments, and a sample gas 935 containing ions emitted from the emission section 30 is supplied to the ion filter 910 .

According to the eighth embodiment, since the humidity of the sample gas 935 is extremely low, highly accurate analysis can be performed without being affected by humidity.

1 first dehumidifying part 2 second dehumidifying part 11 dehumidifying element 21 ion generator 22 ion filter 23 discharge part 24, 224 ion collecting electrode 30 discharge part 31 metal mesh 100, 200, 400, 500, 600, 700, 800 Dehumidifier 225 Drain pipe 226 Cooling unit 511 Laminated dehumidifying element 611, 721, 821 Humidity control circuit 613, 723 Humidity detector 822 Ammeter 900 Ion detector 910 Ion filter 920 Ion detection electrode 930 Dehumidifier

JP 2015-158368 A

Claims (10)

a first dehumidification unit that dehumidifies gas;
a second dehumidifying section that dehumidifies the gas dehumidified by the first dehumidifying section;
a release unit for releasing the gas dehumidified by the second dehumidification unit;
with
The second dehumidification unit includes an ion generator that generates ions from the gas dehumidified by the first dehumidification unit;
an ion filter having opposing first and second electrodes for controlling the mobility of ions produced by the ion generator;
an ion collecting electrode that attracts ions that have passed through the ion filter;
A dehumidifier comprising: 2. The dehumidifier according to claim 1, wherein the first dehumidifying section has a dehumidifying element having a polymer electrolyte membrane. 3. The dehumidifier according to claim 2, wherein said first dehumidifying section has a plurality of said dehumidifying elements stacked on top of each other. The first dehumidifying section is
a first humidity detector that detects the humidity of the gas that has passed through the dehumidifying element;
a first controller that controls the dehumidifying element based on the humidity detected by the first humidity detector;
The dehumidifier according to claim 2 or 3, characterized by comprising: 2. The dehumidifier according to claim 1, wherein the ion filter allows only ions generated from water molecules to pass through the ions generated by the ion generator. The second dehumidifying section is
a cooling unit that cools the ion collecting electrode;
a disposal unit for discarding water liquefied by the ion collecting electrode;
A dehumidifier according to claim 1, characterized by comprising: The second dehumidifying section is
a second humidity detector that detects the humidity of the gas flowing through the discharge section;
a second controller that controls the ion filter based on the humidity detected by the second humidity detector;
The dehumidifier according to any one of claims 1 to 6, characterized by comprising: The first dehumidifying section is
a dehumidifying element comprising a polymer electrolyte membrane;
a first humidity detector that detects the humidity of the gas that has passed through the dehumidifying element;
a first controller that controls the dehumidifying element based on the humidity detected by the first humidity detector;
has
The second dehumidifying section further includes
an ammeter that measures the current flowing through the ion collecting electrode;
a third controller that controls the ion filter based on the humidity calculated from the current measured by the ammeter;
A dehumidifier according to claim 1, characterized by comprising: 9. The dehumidifier according to any one of claims 1 to 8, further comprising a member provided at an entrance of said discharge section and to which a negative potential is applied. A dehumidifier according to any one of claims 1 to 9;
an output unit that contacts the ions passing through the dehumidifier and outputs an electrical characteristic value according to the strength of the contact;
A detection device comprising:

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