Critical ion mobility measuring device

Abstract

The utility model provides a critical ion mobility measuring device. The critical ion mobility measuring device comprises an ion generating system, a high-precision electrometer, an air negative ion measuring instrument and a high-resolution differential electromobility analyzer, the ion generation system is connected with the high-resolution differential electromobility analyzer through a pipeline; the high-resolution differential electromobility analyzer is respectively connected with the high-precision electrometer and the air anion measuring instrument through corresponding pipelines; the other end of the high-precision electrometer and the other end of the negative air ion measuring instrument are connected with the corresponding sucking pumps through the corresponding flow controllers. According to the utility model, the critical ion mobility is calculated according to the ratio of the ion concentration measured by the high-precision electrometer to the ion concentration measured by the air negative ion measuring instrument, and the measurement result of the air negative ion measuring instrument is calibrated, so that the accuracy of the measurement result is improved; according to the utility model, the carrier gas is used for conveying ions; and the critical ion mobility is measured according to a high-precision electrometer and an air negative ion measuring instrument.

Description

TECHNICAL FIELD

[0001] The utility model relates to ion measurement technical field especially a critical ion mobility measurement device. BACKGROUND

[0002] Ion mobility refers to the moving speed of air ions under the action of unit intensity electric field, and critical ion mobility refers to the minimum ion mobility of particles entering the air negative ion measuring instrument along the inner diameter edge of the outer cylinder and being captured by the ion collector.

[0003] Since the ion mobility of particles is greater than or equal to 0.4cm 2 / (v·s), it is considered to be a negative ion, so it is necessary to ensure that the critical mobility of the air negative ion measuring instrument is 0.4cm 2 / (v·s). However, the determination of the critical mobility of the instrument at present is only based on the verification of the theoretical calculation value of the specific size of the measuring instrument, the voltage of the plate and other parameters, and cannot reflect the real situation of the operation of the instrument. UTILITY MODEL CONTENT

[0004] In view of the deficiencies of the prior art, the utility model provides a critical ion mobility measurement device, which is simple in structure, high in practicability, and calibrated by the measurement results, so as to improve the accuracy of the measurement results.

[0005] The technical scheme of the utility model is as follows: a critical ion mobility measurement device, comprising an ion generation system, a high-precision electrometer, an air negative ion measuring instrument, and a high-resolution differential electric mobility analyzer; the ion generation system is connected with the high-resolution differential electric mobility analyzer through a pipeline; the high-resolution differential electric mobility analyzer is connected with the high-precision electrometer and the air negative ion measuring instrument through corresponding pipelines respectively; the other end of the high-precision electrometer and the air negative ion measuring instrument is connected with a flow controller through corresponding pipelines respectively, and the flow controller is further connected with a suction pump.

[0006] Preferably, the ion generation system adopts an electrospray particle generator.

[0007] Preferably, the electrospray particle generator comprises a reactor, an electrospray needle is inserted in the reactor, the tip of the electrospray needle is communicated with an electrospray cavity, and the electrospray cavity is further connected with a dry carrier gas input pipeline.

[0008] As preferred, the electrospray needle is further connected with a high-voltage power supply, and the upper end of the reactor is further communicated with a gas inlet pipe.

[0009] As preferred, the electrospray cavity is connected with the inlet of the differential mobility analyzer through a pipe.

[0010] As preferred, the voltage of the high-voltage power supply is 1.5-3.0 kV.

[0011] As preferred, the dry carrier gas inputted by the dry carrier gas input pipe is nitrogen, clean air or carbon dioxide.

[0012] As preferred, one side of the high-resolution differential mobility analyzer is provided with a polydisperse particle inlet, and the lower end of the high-resolution differential mobility analyzer is further provided with a monodisperse particle output pipe.

[0013] As preferred, the monodisperse particle output pipe adopts a tetrafluoro pipe.

[0014] As preferred, the high-resolution differential mobility analyzer is provided with a high-voltage electrode, and the particles are scanned by the high-voltage electrode with different voltages to screen out monodisperse particles.

[0015] As preferred, the upper end of the high-resolution differential mobility analyzer is provided with a sheath gas inlet, and the lower end is provided with a sheath gas outlet, which is communicated with a sheath flow channel in the high-resolution differential mobility analyzer.

[0016] As preferred, the high-precision electrometer and the air negative ion measuring instrument are further connected with a PC end, and the concentration measured by the high-precision electrometer and the air negative ion measuring instrument is acquired through the PC end.

[0017] As preferred, the air negative ion measuring instrument comprises an outer cylinder and an inner cylinder, and the inner cylinder is further provided with a baffle on one side.

[0018] The air negative ion measuring instrument has the advantages that:

[0019] 1. The utility model discloses a proportion of ion concentration measured by high accuracy electrometer and ion concentration measured by air negative ion measuring instrument, calculates the critical ion mobility, calibrates the measurement result of air negative ion measuring instrument to improve the accuracy of measurement result.

[0020] 2. The utility model discloses through ion generation system and high resolution differential electrical mobility analyzer cooperation, realize corresponding particle size's ion screening, utilize carrier gas to realize ion's delivery simultaneously according to high accuracy electrometer, air negative ion measuring instrument realizes the measurement of critical ion mobility.

[0021] 3. The utility model discloses need not to dismantle the instrument to measure its polar plate voltage, polar plate length etc., and can calculate the critical mobility change curve when the instrument works, and is not a fixed critical mobility value. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is the structural framework drawing of the utility model;

[0023] Figure 2 It is the air negative ion measuring instrument structure schematic view of the utility model;

[0024] In the drawing, 1-ion generation system;2-high resolution differential electrical mobility analyzer;3-high accuracy electrometer;4-air negative ion measuring instrument;5-flow controller;6-pump;7-PC end;

[0025] 11-reactor;12-high voltage power supply;13-electrospray needle;14-electrospray cavity;15-dry carrier gas input pipeline;16-gas inlet pipeline;

[0026] 21-polydispersed particle inlet;22-monodisperse particle output pipeline;23-high voltage electrode;24-sheath gas inlet;25-sheath gas outlet;26-sheath flow channel;

[0027] 41-outer cylinder;42-inner cylinder;43-baffle. DETAILED DESCRIPTION

[0028] The specific implementation of the utility model will be further explained as follows in combination with the drawings:

[0029] For example, Figure 1As shown in the figure, the embodiment provides a critical ion mobility measurement device, comprising an ion generation system 1, a high-precision electrometer 3, an air negative ion measurement instrument 4, and a high-resolution differential electrical mobility analyzer 2; the ion generation system 1 is connected with the high-resolution differential electrical mobility analyzer 2 through a pipeline; the high-resolution differential electrical mobility analyzer 2 is connected with the high-precision electrometer 3 and the air negative ion measurement instrument 4 through corresponding pipelines respectively; the other end of the high-precision electrometer 3 and the air negative ion measurement instrument 4 is connected with a flow controller 5 through corresponding pipelines respectively, and the flow controller 5 is further connected with a gas suction pump 6.

[0030] As preferred in the embodiment, the ion generation system 1 adopts an electrospray particle generator.

[0031] As preferred, the electrospray particle generator comprises a reactor 11, and an electrospray needle 13 is inserted in the reactor 11; the electrospray needle 13 in the reactor 11 is further connected with a high-voltage power supply 12 through a wire.

[0032] The upper end of the reactor 11 is further communicated with an air inlet pipeline 16.

[0033] The tip of the electrospray needle 13 is communicated with an electrospray cavity 14, and the electrospray cavity 14 is further connected with a dry carrier gas input pipeline 15; the electrospray cavity 14 is further grounded through a wire.

[0034] In the embodiment, by dissolving ionized solute molecules in a volatile solvent in the reactor 11, the solution is discharged by the high-voltage power supply 12, a certain pressure gas is introduced into the reactor 11 through the air inlet pipeline 16, so that the charged solution reaches the tip of the electrospray needle 13 along the electrospray needle 13; is ejected and broken into tiny droplets; the ejected droplets volatilize the solvent under the action of the dry carrier gas, and the surface charge density increases; when the charge density of the droplets exceeds the Rayleigh limit, the repulsive force between the surface charges will cause Coulomb explosion, bare ion emission, and a series of charged particles.

[0035] As preferred in the embodiment, the electrospray cavity 14 is connected with the inlet of the high-resolution differential electrical mobility analyzer 2 through a pipeline.

[0036] As preferred in the embodiment, the voltage of the high-voltage power supply 12 is 1.5-3.0 kV.

[0037] As preferred in the embodiment, the dry carrier gas input by the dry carrier gas input pipeline 15 is nitrogen, or clean air, or carbon dioxide.

[0038] As preferred in the embodiment, the high-resolution differential electrical mobility analyzer 2 is provided with a polydisperse particle inlet 21 on one side, and a monodisperse particle output pipeline 22 is further provided at the lower end of the high-resolution differential electrical mobility analyzer 2. The monodisperse particle output pipeline 22 is a four-fluorine pipeline.

[0039] A high-voltage electrode 23 is arranged in the high-resolution differential electrical mobility analyzer 2, and the high-voltage electrode 23 scans the particles by different voltages. Only the particles with corresponding particle sizes can pass through the corresponding voltage, so that the monodisperse particles are screened out.

[0040] A sheath gas inlet 24 is arranged at the upper end of the high-resolution differential electrical mobility analyzer 2, and a sheath gas outlet 25 is arranged at the lower end, which is communicated with a sheath flow channel 26 in the differential electrical mobility analyzer 2.

[0041] As preferred in the embodiment, the high-precision electrometer 3 and the air negative ion measuring instrument 4 are further connected with a PC end 7, and the concentration measured by the high-precision electrometer 3 and the air negative ion measuring instrument 4 is acquired through the PC end 7. The high-precision electrometer 3 used in the embodiment is a 3068B aerosol electrometer of TSI company.

[0042] As preferred in the embodiment, the air negative ion measuring instrument 4 used in the embodiment is a COM-3200PRO air negative ion measuring instrument. As shown in the figure, the air negative ion measuring instrument 4 mainly comprises an outer cylinder 41 and an inner cylinder 42, and a baffle 43 is further arranged on one side of the inner cylinder 42. Figure 2 In the embodiment, the inner diameter of the outer cylinder 41 is r2, the outer diameter of the inner cylinder 42 is r1, and the radius of the baffle 43 is R. Meanwhile, a certain voltage is applied to the outer cylinder 41, and the inner cylinder 42 is grounded through a wire.

[0043] In addition, the air negative ion measuring instrument 4 of the embodiment can also not be provided with the baffle 43, and if the baffle 43 is not provided, R=r1. The critical ion mobility Zp in the embodiment is calculated by the following expression:

[0044]

[0045] In the expression, Z0 is the ion mobility, r1 is the outer diameter of the inner cylinder, r2 is the inner diameter of the outer cylinder, R is the radius of the baffle, N1 is the concentration measured by the air negative ion measuring instrument, and N2 is the concentration measured by the high-precision electrometer.

[0046] The above embodiment and description only illustrate the principle and the best embodiment of the utility model, and various changes and improvements can be made to the utility model without departing from the spirit and scope of the utility model. These changes and improvements all fall within the scope of the utility model.

Claims

1. A critical ion mobility measurement apparatus, characterized by, The application relates to an air ion measurement device, which comprises an ion generation system (1), a high-precision electrometer (3), an air negative ion measurement instrument (4) and a high-resolution differential electric mobility analyzer (2); the ion generation system (1) is connected with the high-resolution differential electric mobility analyzer (2) through a pipeline; the high-resolution differential electric mobility analyzer (2) is connected with the high-precision electrometer (3) and the air negative ion measurement instrument (4) through corresponding pipelines respectively; the other ends of the high-precision electrometer (3) and the air negative ion measurement instrument (4) are connected with a flow controller (5) through corresponding pipelines respectively, and the flow controller (5) is further connected with a suction pump (6).

2. The critical ion mobility measurement device of claim 1, wherein: The ion generation system (1) adopts an electrospray particle generator.

3. A critical ion mobility measurement device according to claim 2, wherein: The electrospray particle generator comprises a reactor (11), an electrospray needle (13) is arranged in the reactor (11), the electrospray needle (13) in the reactor (11) is further connected with a high-voltage power supply (12) through a wire, and the upper end of the reactor (11) is in communication with an air inlet pipeline (16); the tip of the electrospray needle (13) is in communication with an electrospray cavity (14), and the electrospray cavity (14) is further connected with a dry carrier gas input pipeline (15).

4. A critical ion mobility measurement apparatus as claimed in claim 3, wherein: The electrospray cavity (14) is connected with the inlet of the high-resolution differential electric mobility analyzer (2) through a pipeline.

5. The critical ion mobility measurement device of claim 3, wherein: The voltage of the high-voltage power supply (12) is 1.5-3.0 kV.

6. The critical ion mobility measurement device of claim 3, wherein: The dry carrier gas input by the dry carrier gas input pipeline (15) is nitrogen, clean air or carbon dioxide.

7. The device of claim 1, wherein: The high-resolution differential electric mobility analyzer (2) is provided with a polydisperse particle inlet (21) on one side, and is further provided with a monodisperse particle output pipeline (22) at the lower end; The high-resolution differential electric mobility analyzer (2) is provided with a high-voltage electrode (23) therein; The upper end of the high-resolution differential electric mobility analyzer (2) is provided with a sheath gas inlet (24), and the lower end is provided with a sheath gas outlet (25); the sheath gas outlet (25) is in communication with a sheath flow channel (26) in the high-resolution differential electric mobility analyzer (2).

8. A critical ion mobility measurement apparatus as claimed in claim 7, wherein: The monodisperse particle output pipeline (22) adopts a tetrafluoro pipeline.

9. The device of claim 1, wherein: The high-precision electrometer (3) and the air negative ion measurement instrument (4) are further connected with a PC terminal (7), and the concentration measured by the high-precision electrometer (3) and the air negative ion measurement instrument (4) is acquired through the PC terminal (7).

10. The critical ion mobility measurement device of claim 1, wherein: The air negative ion measurement instrument (4) comprises an outer cylinder (41) and an inner cylinder (42), and a baffle (43) is further arranged on one side of the inner cylinder (42).

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