Photoionization measurement device and method

Abstract

The present application relates to a photoionization measurement device and method, and the photoionization measurement device of the present application includes: an ionization chamber, a light-emitting component, a measurement chamber, and a detection component; the ionization chamber is configured to allow the light emitted by the light-emitting component to enter the ionization cavity, so as to ionize the gas to be measured in the ionization cavity; the measurement chamber has an outlet channel that runs through the measurement chamber, and the outlet channel is connected to the ionization cavity, so that the ionized gas to be measured can flow out; the detection component includes an electrically connected collection electrode and a bias electrode, which are used to detect the ionized gas to be measured in the outlet channel. Therefore, the present application is selective, can measure the gas to be measured in a targeted manner, and improves the accuracy of the measurement of the gas to be measured.

Description

Technical Field

[0001] The present application relates to the field of detectors, and in particular to a photoionization measurement device and method. Background Art

[0002] In the prior art, the photoionization gas detector (PID) is not selective and cannot specifically measure the gas to be measured, thereby improving the accuracy of the measurement of the gas to be measured. For example, when the gas to be measured is a mixture of benzene and toluene, the prior art cannot distinguish between benzene and toluene and cannot select only benzene to be measured. Summary of the invention

[0003] The purpose of the present application is to provide a photoionization measurement device and method, which are selective and can specifically measure the gas to be measured, thereby improving the accuracy of the measurement of the gas to be measured.

[0004] In order to achieve the above objectives,

[0005] In a first aspect, the present application provides a photoionization measurement device, comprising: an ionization chamber, a light-emitting component, a measuring chamber, a voltage controller, a flow controller and a detection component; the light-emitting component is used to emit light; the ionization chamber has an ionization cavity for accommodating a gas to be measured, and the ionization chamber is configured to allow light emitted by the light-emitting component to enter the ionization cavity so as to ionize the gas to be measured in the ionization cavity; the measuring chamber has an outlet channel running through the measuring chamber, and the outlet channel is connected to the ionization cavity so that the ionized gas to be measured can flow out; the detection component comprises an electrically connected collecting electrode and a bias electrode, which are used to detect the ionized gas to be measured in the outlet channel, and the voltage controller is electrically connected to the detection component for controlling the voltage of the detection component.

[0006] In the second aspect, the present application provides a photoionization measurement method, which is applied to the above-mentioned photoionization measurement device, and the photoionization measurement method includes: obtaining the response sensitivity of the collecting block to different components in the gas to be measured; obtaining the response current of the collecting block; and calculating the component concentration information of the gas to be measured based on the response sensitivity of the collecting block to different components in the gas to be measured and the response current of the collecting block.

[0007] Compared with the prior art, the present application has the following beneficial effects: the present application is selective and can specifically measure the gas to be measured, thereby improving the accuracy of the measurement of the gas to be measured. For example, when the gas to be measured is a mixture of benzene and toluene, the prior art cannot distinguish between benzene and toluene, and cannot choose to measure only benzene, while the present application can choose to measure only benzene, or only toluene, and can also simultaneously measure the concentration of benzene and the concentration of toluene in the mixture. The present application can deduct the interference of ambient humidity on gas measurement, thereby improving the accuracy of the measurement of the gas to be measured. By setting up multiple collecting blocks, the present application can measure the content of different components in the gas to be measured by utilizing the different response sensitivities of multiple collecting blocks to different components in the gas to be measured, conduct qualitative and quantitative analysis on the complex gas composition to be measured, and distinguish the various components in the gas to be measured. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0009] Figure 1 An exploded view of a photoionization measurement device according to an embodiment of the present application.

[0010] Figure 2 A top view of a photoionization measurement device according to an embodiment of the present application.

[0011] Figure 3 A cross-sectional view of a photoionization measurement device according to an embodiment of the present application.

[0012] Figure 4 This is a three-dimensional diagram of a measurement chamber according to an embodiment of the present application.

[0013] Figure 5 This is a front view of a measurement chamber according to an embodiment of the present application.

[0014] Figure 6 A cross-sectional view of a measurement chamber according to an embodiment of the present application.

[0015] Figure 7 This is a three-dimensional diagram of a photoionization measurement device according to an embodiment of the present application.

[0016] Figure 8 A top view of a photoionization measurement device according to an embodiment of the present application.

[0017] Fig. 9 A cross-sectional view of a photoionization measurement device according to an embodiment of the present application.

[0018] Fig.10 A cross-sectional view of a photoionization measurement device according to an embodiment of the present application.

[0019] Fig.11 This is a three-dimensional diagram of a photoionization measurement device according to an embodiment of the present application.

[0020] Fig.12 This is a three-dimensional diagram of a photoionization measurement device according to an embodiment of the present application.

[0021] Fig.13 A top view of a photoionization measurement device according to an embodiment of the present application.

[0022] Fig.14 A cross-sectional view of a photoionization measurement device according to an embodiment of the present application.

[0023] Fig.15 A cross-sectional view of a photoionization measurement device according to an embodiment of the present application.

[0024] Icons: 100-photoionization measuring device; 200-ionization chamber; 210-ionization cavity; 210a-inner top wall of ionization cavity; 210b-outer side wall of ionization chamber; 210c-outer top wall of ionization chamber; 210d-outer bottom wall of ionization chamber; 220-mounting step hole; 300-light-emitting component; 310-ultraviolet lamp; 400-measuring chamber; 410-exit channel; 411-upper inner wall of channel; 412-lower inner wall of channel; 413-annular side wall of channel; 500-detection component; 510-collecting electrode; 511-collecting electric block; 512-first isolating member; 520-bias electrode; 521-first opening; 522-light shielding member; 650-inlet pipe; 700-voltage controller; 800-flow controller. DETAILED DESCRIPTION

[0025] The terms "first", "second", "third", etc. are only used to distinguish the description, and do not represent the arrangement number, nor can they be understood as indicating or implying relative importance. In addition, the terms "horizontal", "vertical", "overhanging", etc. do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted. In the description of this application, it should be noted that the orientation or position relationship indicated by the terms "inside", "outside", "left", "right", "up", "down", etc. is based on the orientation or position relationship shown in the accompanying drawings, or the orientation or position relationship in which the product of the application is usually placed when in use. It is only for the convenience of describing the application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the application. In the description of this application, unless otherwise clearly specified and limited, the terms "set", "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements.

[0026] The technical solution of the present application will be described clearly and completely below in conjunction with the accompanying drawings.

[0027] Please refer to Figure 1 , which is an exploded view of a photoionization measurement device 100 shown in an embodiment of the present application. A photoionization measurement device 100 includes: an ionization chamber 200, a light emitting component 300, a measurement chamber 400, a detection component 500 and an inlet pipe 650. The measurement chamber 400 is tubular and has an outlet channel 410 that passes through the measurement chamber 400. The outlet channel 410 can be a straight channel or a curved channel. The inlet pipe 650 can be a straight pipe or a curved pipe.

[0028] The light emitting assembly 300 is disposed on the outer bottom wall 210d of the ionization chamber, the inlet pipe 650 and the measuring chamber 400 are both disposed on the outer side wall 210b of the ionization chamber, and the inlet pipe 650 and the measuring chamber 400 are disposed opposite to each other, and are respectively located on the left and right sides of the ionization chamber 200. In one embodiment, the axis of the inlet pipe 650 and the axis of the measuring chamber 400 are arranged to coincide, and the axis of the ionization chamber 200 and the axis of the measuring chamber 400 are arranged to be perpendicular.

[0029] The inlet pipe 650 and the measuring chamber 400 and the ionization chamber 200 may be integrally formed, or may be connected together by bolt connection, welding, or the like.

[0030] The detection component 500 includes an electrically connected collecting electrode 510 and a bias electrode 520, which are used to detect the ionized gas to be measured in the outlet channel 410. The collecting electrode 510 and the bias electrode 520 are both an integral structure, and are both arranged on the inner wall of the outlet channel 410, and are arranged relative to each other. Among them, the collecting electrode 510 is a cathode, which is used to receive positive ions formed after the gas to be measured is ionized, and the collecting electrode 510 of an integral structure can be called a collecting electric block 511; the bias electrode 520 is an anode, which is used to receive electrons and / or negative ions formed after the gas to be measured is ionized. A first deflection electric field that is conducive to detection can be formed between the collecting electrode 510 and the bias electrode 520.

[0031] The photoionization measurement device 100 further includes: a voltage controller 700, which is electrically connected to the detection component 500 and is used to control the voltage of the detection component 500. The voltage controller 700 can control the collection voltage between the collection electrode 510 and the bias electrode 520 to be constant, and can also adjust the collection voltage between the collection electrode 510 and the bias electrode 520 to reach a specified voltage value. In one embodiment, the voltage controller 700 can also include a voltage sensor for detecting voltage.

[0032] The photoionization measurement device 100 further includes a flow controller 800 , which is a gas flow controller disposed at the outlet channel 410 and used to control the flow of the gas to be measured.

[0033] The voltage controller 700 may be directly disposed in the photoionization measurement device 100 or may be externally disposed, and the flow controller 800 may be directly disposed in the photoionization measurement device 100 or may be externally disposed.

[0034] In one embodiment, the photoionization measurement device 100 further includes a control center, which includes a communicator, a memory, a processor, and a human-computer interaction component, and is used to control the voltage controller 700 and the flow controller 800. In one embodiment, the control center may also include a humidity sensor, which is disposed in the ionization chamber 200 and is used to detect the humidity of the gas to be measured; the control center may also include at least one current sensor, which is connected to the detection component 500 and is used to detect the current.

[0035] In one operation process, the organic gas to be measured is first brought into the ionization chamber 200 from the inlet pipe 650. In the ionization chamber 200, the organic gas to be measured is dissociated into electrons and organic cations under the irradiation of ultraviolet light emitted by the light-emitting component 300. Then, the electrons and organic cations are brought into the measuring chamber 400 along with the airflow of the organic gas to be measured. Then, the electrons and organic cations in the airflow are deflected under the action of the first deflection electric field, and the positive ions flow to the collecting electrode 510 and the electrons flow to the bias electrode 520, thereby forming a signal current, which is then amplified and measured in the detection circuit in the detection component 500, and the measured gas is discharged from the outlet channel 410 of the measuring chamber 400.

[0036] The present embodiment is selective, and the voltage change of the detection component 500 is controlled by the voltage controller 700, and the flow rate of the gas to be measured is controlled to be fixed by the flow controller 800, so that the gas to be measured can be measured in a targeted manner, thereby improving the accuracy of the measurement of the gas to be measured. For example, when the gas to be measured is a mixture of benzene and toluene, the prior art cannot distinguish between benzene and toluene and cannot choose to measure only benzene. However, the present application uses the following method embodiment to choose to measure only benzene, or toluene, and can also simultaneously measure the benzene concentration and toluene concentration in the mixture. For example, the following method can be used to calculate the benzene concentration and / or toluene concentration in the mixture using the equations in the combined method embodiment.

[0037] In another embodiment, the photoionization measurement device is not provided with a flow controller 800 , and the gas to be measured is directly introduced at a uniform speed.

[0038] In another operation process, the voltage of the detection component 500 is controlled to remain constant by the voltage controller 700, and the flow rate of the gas to be tested is controlled by the flow controller 800. At this time, the following method embodiment is also used to choose to measure only benzene, or only toluene, or the benzene concentration and toluene concentration in the mixed gas can be measured simultaneously.

[0039] In addition, the detection component 500 is partially or completely disposed in the measuring chamber 400, and physical isolation is used to partially or completely block the light irradiating the surface of the detection component 500, thereby reducing the risk of damage to the detection component 500 due to long-term exposure to light emitted by the light-emitting component 300, thereby extending the service life of the detection component 500 and improving the accuracy of measurement.

[0040] Please refer to Figure 2 , which is a top view of a photoionization measurement device 100 shown in one embodiment of the present application. Figure 3, which is a cross-sectional view of a photoionization measurement device 100 shown in an embodiment of the present application. The light emitting component 300 may include an ultraviolet lamp 310 for emitting light; the ionization chamber 200 has an ionization cavity 210 for accommodating the gas to be measured, and the ionization chamber 200 is configured to allow the light emitted by the light emitting component 300 to enter the ionization cavity 210, so as to ionize the gas to be measured in the ionization cavity 210. The gas to be measured may be a gas sample containing volatile organic compounds (VOCs).

[0041] In this embodiment, the ionization chamber 200, the measuring chamber 400 and the inlet pipe 650 are an integrally formed pipe structure, the ionization chamber 200 is a hollow cylindrical shape, the measuring chamber 400 and the inlet pipe 650 are square tube shapes, and the axial length of the measuring chamber 400 is greater than the axial length of the inlet pipe 650. A mounting step hole 220 penetrating the outer bottom wall 210d of the ionization chamber is provided in the outer bottom wall 210d of the ionization chamber, and the light-emitting end of the light-emitting component 300 is installed in the mounting step hole 220, so that the mounting step hole 220 can be used to allow the light emitted by the light-emitting component 300 to enter the ionization chamber 210. At this time, the material of the ionization chamber 200, the measuring chamber 400 and the inlet pipe 650 can be made of a light-shielding material such as an opaque plastic, or can be made of a light-transmitting material such as glass or transparent plastic. Among them, a sealing ring can be provided between the mounting step hole 220 and the light-emitting component 300 to prevent leakage of the gas to be measured.

[0042] In another embodiment, the ionization chamber 200 is made of a light-transmitting material such as glass or transparent plastic. The light-emitting component 300 is disposed outside the ionization chamber 200 and does not extend into the ionization chamber 200, so that the light transmittance of the ionization chamber 200 can be utilized to allow the light emitted by the light-emitting component 300 to enter the ionization cavity 210.

[0043] In another embodiment, a light-transmitting member such as a light-transmitting film is provided at the mounting step hole 220 by means of snap connection or bonding, and the light-emitting component 300 is disposed as a whole outside the ionization chamber 200 and does not extend into the ionization chamber 200 , so that the light-transmitting member can be used to allow the light emitted by the light-emitting component 300 to enter the ionization cavity 210 .

[0044] The outlet channel 410 is connected to the ionization chamber 210 to allow the ionized gas to flow out. The outlet channel 410 is a straight channel arranged horizontally, and the outlet channel 410 is a cylindrical hole or a square hole. The axial direction of the outlet channel 410 is arranged to intersect with the direction of the light emitted by the light-emitting component 300. In this embodiment, the axial direction of the outlet channel 410 is the left-right direction, and the direction of the light emitted by the light-emitting component 300 is upward. The axial direction of the outlet channel 410 is perpendicular to the direction of the light emitted by the light-emitting component 300.

[0045] The inner wall of the outlet channel 410 includes an upper inner wall 411 and a lower inner wall 412 that are arranged opposite to each other. An installation groove is respectively provided on the upper inner wall 411 and the channel. The collecting electrode 510 is located below the bias electrode 520. The collecting electrode 510 is embedded in the installation groove of the lower inner wall 412, and the bias electrode 520 is embedded in the installation groove of the upper inner wall 411, so that the bias electrode 520 and the collecting electrode 510 are arranged opposite to each other up and down.

[0046] In this embodiment, the detection components 500 are all arranged in the measurement chamber 400, so that the measurement of the gas to be measured is all carried out in the measurement chamber 400, so that the measurement of the gas to be measured occurs after the ionization process, thereby improving the accuracy of the measurement. In addition, the detection components 500 are all arranged in the measurement chamber 400, and the light irradiated to the surface of the detection components 500 is completely blocked by physical isolation, thereby reducing the risk of damage to the detection components 500 due to long-term irradiation of the light emitted by the light emitting component 300, and reducing the baseline noise interference, thereby extending the service life of the detection components 500 and improving the accuracy of the measurement.

[0047] Please refer to Figure 4 , which is a three-dimensional diagram of a measurement chamber 400 according to an embodiment of the present application. Figure 5 , which is a front view of a measurement chamber 400 according to an embodiment of the present application. Figure 6 , which is a cross-sectional view of a measuring chamber 400 shown in an embodiment of the present application. The measuring chamber 400 and the ionization chamber 200 are split structures and can be connected together by bolt connection, welding or plugging. A sealing ring can be provided at the connection between the measuring chamber 400 and the ionization chamber 200 to prevent air leakage.

[0048] The measuring chamber 400 is a square tube structure, the collecting electrode 510 is located above the bias electrode 520, the collecting electrode 510 is attached to the upper inner wall 411 of the channel by pasting or the like, and the bias electrode 520 is attached to the lower inner wall 412 of the channel by pasting or embedding or the like. The measuring chamber 400 is a rectangular parallelepiped structure, the outlet channel 410 is also a rectangular parallelepiped structure, and the transverse cross-sectional size of the collecting electrode 510, the transverse cross-sectional size of the bias electrode 520, the size of the upper inner wall 411 of the channel, and the size of the lower inner wall 412 of the channel are the same.

[0049] Please refer to Figure 7 , which is a three-dimensional diagram of a photoionization measurement device 100 shown in one embodiment of the present application. Figure 8 , which is a top view of a photoionization measurement device 100 shown in one embodiment of the present application. Fig. 9, which is a cross-sectional view of a photoionization measurement device 100 shown in an embodiment of the present application. The collecting electrode 510 includes a plurality of collecting blocks 511 arranged at intervals, and a first isolating member 512 is sandwiched between two adjacent collecting blocks 511. The first isolating member 512 is made of insulating materials such as plastic and rubber, and is used to isolate two adjacent collecting blocks 511. Therefore, in this embodiment, by setting a plurality of collecting blocks 511, the different response sensitivities of the plurality of collecting blocks 511 to different components in the gas to be measured can be utilized to measure the contents of different components in the gas to be measured.

[0050] The collecting electrode 510 is located below the bias electrode 520 . The collecting electrode 510 and the first isolating member 512 are both embedded in the mounting groove of the lower inner wall 412 of the channel, and the bias electrode 520 is embedded in the mounting groove of the upper inner wall 411 of the channel.

[0051] In this embodiment, the collector block 511 and the first isolating member 512 are both in the shape of a cuboid. The width of the collector block 511 is greater than the width of the first isolating member 512, the height of the collector block 511 is equal to the height of the first isolating member 512, and the length of the collector block 511 is equal to the length of the first isolating member 512.

[0052] There are two collecting blocks 511 and one first isolating member 512. The axial length of the measuring chamber 400 is less than the axial length of the inlet pipe 650. The material of the first isolating member 512 is polytetrafluoroethylene (PTFE). When there are two collecting blocks 511, there can be two voltage controllers 700 to control the voltage between the bias electrode 520 and the two collecting blocks 511 respectively.

[0053] Please refer to Fig.10 , which is a cross-sectional view of a photoionization measurement device 100 shown in an embodiment of the present application. In this embodiment, five collecting electrodes 510 are provided and four first isolating members 512 are provided. The axial length of the measuring chamber 400 is greater than the axial length of the inlet tube 650. The light-emitting component 300 is disposed on the outer bottom wall 210d of the ionization chamber, and the measuring chamber 400 has an outlet channel 410 that passes through the measuring chamber 400. The inlet tube 650 and the measuring chamber 400 are both disposed on the outer side wall 210b of the ionization chamber, and the inlet tube 650 and the measuring chamber 400 are arranged opposite to each other, and are respectively located on the left and right sides of the ionization chamber 200.

[0054] Please refer to Fig.11, which is a stereoscopic diagram of a photoionization measurement device 100 shown in an embodiment of the present application. The light-emitting assembly 300 is arranged on the outer bottom wall 210d of the ionization chamber, the inlet pipe 650 is arranged on the outer side wall 210b of the ionization chamber, and the measuring chamber 400 is arranged on the outer top wall 210c of the ionization chamber. The measuring chamber 400 and the light-emitting assembly 300 are respectively located on the upper and lower sides of the ionization chamber 200. The axis of the inlet pipe 650 and the axis of the measuring chamber 400 are vertically arranged, and the axis of the ionization chamber 200 and the axis of the measuring chamber 400 are coincidently arranged. The axial length of the inlet pipe 650 and the axial length of the measuring chamber 400 can be equal or unequal. In this embodiment, the axial length of the inlet pipe 650 is greater than the axial length of the measuring chamber 400.

[0055] Please refer to Fig.12 , which is a three-dimensional diagram of a photoionization measurement device 100 shown in an embodiment of the present application. The axial length of the inlet pipe 650 is smaller than the axial length of the measurement chamber 400 .

[0056] Please refer to Fig.13 , which is a top view of a photoionization measurement device 100 shown in one embodiment of the present application. Fig.14 , which is a cross-sectional view of a photoionization measurement device 100 shown in an embodiment of the present application. The outlet channel 410 is a vertically arranged square straight channel, and the axial direction of the outlet channel 410 is longitudinal (up and down direction), which is arranged in the same direction as the light emitted by the light emitting component 300.

[0057] The outlet channel 410 is provided with rounded corners, and the inner wall of the outlet channel 410 is a channel annular side wall 413 as a whole; an annular installation groove is provided on the channel annular side wall 413, and the collecting block 511 and the first isolating member 512 of the collecting electrode 510 are embedded in the installation groove of the channel annular side wall 413. In this embodiment, since the collecting block 511 and the first isolating member 512 are embedded, the collecting block 511 and the first isolating member 512 can be reduced from being irradiated by the ultraviolet light of the ultraviolet lamp 310, and the risk of the detection component 500 being damaged due to long-term exposure to light can be reduced.

[0058] In this embodiment, the collecting block 511 and the first isolating member 512 are both annular sheets. The radial cross section of the outlet channel 410 is a rounded rectangle, the width of the collecting block 511 is equal to the width of the first isolating member 512, the length of the collecting block 511 is equal to the length of the first isolating member 512, and the height of the collecting block 511 is greater than the height of the first isolating member 512. Two collecting blocks 511 are provided, and two first isolating members 512 are provided.

[0059] The inner wall of the ionization chamber 210 includes the inner top wall 210a of the ionization chamber, and the bias electrode 520 is arranged on the inner top wall 210a of the ionization chamber, so that the bias electrode 520 can be relatively far away from the light-emitting component 300. At least one first opening 521 is provided on the bias electrode 520 to communicate with the outlet channel 410 and the ionization chamber 210. In this embodiment, the bias electrode is an annular sheet, and the radial cross-sectional area of ​​the bias electrode is greater than the radial cross-sectional area of ​​the collector block 511.

[0060] The photoionization measurement device 100 further includes: a light shielding member 522, which is disposed between the light emitting assembly 300 and the bias electrode 520. The light shielding member 522 is closely attached to or bonded to the bias electrode 520, and is used to shield the light irradiated to the surface of the bias electrode 520. The material of the light shielding member 522 can be a material that can shield ultraviolet light. The shape and size of the light shielding member 522 are the same as those of the bias electrode 520, and both are annular perforated sheets.

[0061] In this embodiment, the radial cross-section of the first opening 521 is smaller, the radial cross-section of the outlet channel 410 is larger, and the aperture of the first opening 521 is smaller than the aperture of the outlet channel 410. In addition to blocking the light irradiating the surface of the bias electrode 520, the shading member 522 can also block the light irradiating the surface of the collecting electrode 510.

[0062] In this embodiment, the collecting electrode 510 is located in the measuring chamber 400, and the bias electrode 520 is located on the inner top wall 210a of the ionization cavity away from the light emitting component 300, and the detection component 500 is partially arranged in the measuring chamber 400, so that the measurement of the gas to be measured is partially occurred in the measuring chamber 400, so that the measurement of the gas to be measured occurs as much as possible after the ionization process, thereby improving the accuracy of the measurement. In addition, the detection component 500 is partially arranged in the measuring chamber 400, and the light irradiating the surface of the detection component 500 is physically isolated or completely blocked by setting a light shielding member 522, thereby reducing the risk of the detection component 500 being damaged by long-term exposure to the light emitted by the light emitting component 300, thereby extending the service life of the detection component 500 and improving the accuracy of the measurement.

[0063] Please refer to Fig.15 , which is a cross-sectional view of a photoionization measurement device 100 shown in an embodiment of the present application. Five collecting blocks 511 are provided, and five first isolation members 512 are provided.

[0064] In a second aspect, the present application provides a photoionization measurement method, which can be applied to the control center of the photoionization measurement device 100. The specific principle of the photoionization measurement method is as follows:

[0065] like Figure 5 and Figure 6As shown, the width of the transverse section of the outlet channel 410, the width of the transverse section of the collecting electrode 510 and the width of the transverse section of the bias electrode 520 are all a, the length of the transverse section of the outlet channel 410, the length of the transverse section of the collecting electrode 510 and the length of the transverse section of the bias electrode 520 are all L, and the distance between the collecting electrode 510 and the bias electrode 520 and the height of the outlet channel 410 are all d. The time required for the gas to be measured to pass through the outlet channel 410 of the measuring chamber 400 can be calculated using formula (1):

[0066]

[0067] Wherein, τ is the time required for the gas to be measured to pass through the outlet channel 410 of the measuring chamber 400; F is the gas flow rate; V=adL is the volume of the outlet channel 410; A=ad is the cross-sectional area of ​​the outlet channel 410 along the direction perpendicular to the gas flow.

[0068] The field strength E of the electric field generated between the collecting electrode 510 and the bias electrode 520 can be calculated using formula (2):

[0069]

[0070] Wherein, U is the voltage applied between the collecting electrode 510 and the bias electrode 520 ; and d is the distance between the collecting electrode 510 and the bias electrode 520 .

[0071] The charged ions i include cations generated by the ionization of the gas to be measured. After the charged ions i are introduced from the ionization chamber 200 into the measurement chamber 400, the charged ions i are deflected by the electric field generated between the collecting electrode 510 and the bias electrode 520. Not all ions are collected by the collecting electrode 510. The time t required for the charged ions i to be collected by the collecting electrode 510 is i It is related to the vertical distance between the charged ion i and the collecting electrode 510 after the charged ion i enters the measuring chamber 400.

[0072] The time t required for the charged ions i to be collected by the collecting electrode 510 i It can be calculated using formula (3):

[0073]

[0074] Among them, m i is the mass of charged ions i in the gas to be measured; q i is the charge of the charged ion i; U is the voltage applied between the collecting electrode 510 and the bias electrode 520, y i is the vertical distance between the charged ion i and the collecting electrode 510.

[0075] According to formula (3), it can be seen that the time required for the charged ions i that are close to the collecting electrode 510 to be collected by the collecting electrode 510 is shorter, and the time required for the charged ions i that are far from the collecting electrode 510 to be collected is longer. i = equal to the distance d between the collecting electrode 510 and the bias electrode 520, ie, y i = d, the time required for the charged ion i to be collected by the collecting electrode 510 is t i longest.

[0076] When the maximum time required for the charged ions i to be collected by the collecting electrode 510 is less than the time τ required for the gas to be measured to pass through the outlet channel 410 of the measuring chamber 400, that is, When , all charged ions i entering the measuring chamber 400 are collected by the collecting electrode 510. At this time, the collecting electrode 510 has the highest collection efficiency and the highest sensitivity.

[0077] When the maximum time required for the charged ions i to be collected by the collecting electrode 510 is greater than the time τ required for the gas to be measured to pass through the outlet channel 410 of the measuring chamber 400, that is, When , only part of the charged ions i entering the measuring chamber 400 are collected by the collecting electrode 510. At this time, only the vertical distance y between the charged ions i and the collecting electrode 510 is i satisfy The charged ions i are collected, and the vertical distance y between the charged ions i and the collecting electrode 510 is i satisfy The charged ions i are not collected.

[0078] According to the above relationship, the proportion of charged ions i collected can be calculated using formula (4):

[0079]

[0080] Among them, R i is the proportion of charged ions i collected by the collecting electrode 510; y i (τ) is the maximum distance between the charged ion i and the collecting electrode 510 when the charged ion i can be collected; m i is the mass of charged ions i in the gas to be measured; q i is the charge of the charged ion i; U is the voltage applied between the collecting electrode 510 and the bias electrode 520, y i is the vertical distance between the charged ion i and the collecting electrode 510.

[0081] According to formula (4), we can get R iIt is related to the mass-to-charge ratio of the charged ion i, the flow rate of the gas to be measured, the collection voltage applied in the detection component 500 and the electrode structure design of the photoionization measurement device 100. Under the condition that the structure of the photoionization measurement device 100 is fixed, the proportions of charged ions i with different mass-to-charge ratios collected on the collection electrode 510 are different. More charged ions i with a small mass-to-charge ratio are collected, and fewer charged ions i with a large mass-to-charge ratio are collected.

[0082] The conditions for formula (4) to be valid are as follows: (1) the ionization chamber 200 and the measuring chamber 400 in the photoionization measuring device 100 are separated; (2) the gas to be measured flows through the ionization chamber 200 and the measuring chamber 400 in sequence at a fixed flow rate; (3) the bias electrode 520 and the collecting electrode 510 are both perpendicular to the gas flow direction of the gas to be measured; (4) the structural dimensions of the bias electrode 520 and the collecting electrode 510 can be designed according to the characteristics of the gas to be measured; (5) the voltage between the bias electrode 520 and the collecting electrode 510 can be adjusted according to the characteristics of the gas to be measured.

[0083] Accordingly, in the case where the structure design of the photoionization measurement device 100 is fixed and the gas flow rate is fixed, and there is only one set of collecting electrodes 510 and biasing electrodes 520 (a collecting electrode block 511 and a biasing electrode, such as Figure 1-Figure 6 When the collecting electrode 510 has a structure, the voltage of the collecting electrode 510 can be adjusted to perform multiple measurements on the gas to be measured. Under different collecting voltage conditions, the electrode has different response sensitivities to ions of different mass-to-charge ratios, and multiple response equations can be obtained. Then, the concentrations of different components in the mixed gas can be solved by simultaneous equations to achieve selective measurement of the target gas in a complex gas environment. Under the premise that the collecting voltage remains unchanged, multiple groups of bias electrodes 520 and the collecting electrode 510 (multiple collecting electrodes 511 and a bias electrode, such as Figure 7-Figure 15 The structure of the mixed gas is used to measure and solve the concentration of different gases in the mixed gas, so as to realize the selective measurement of the target gas in a complex gas environment.

[0084] Therefore, the photoionization measurement method can selectively measure VOC gas based on this feature, and can also measure the content of different components in the mixed gas.

[0085] In one embodiment, the photoionization measurement method includes the following steps:

[0086] Step S110: obtaining the response sensitivity of the collector block 511 to different components in the gas to be tested.

[0087] Step S120: obtaining the response current of the collector block 511;

[0088] Step S130: Calculate and obtain the component concentration information of the gas to be measured according to the response sensitivity of the collecting block 511 to different components in the gas to be measured and the response current of the collecting block 511.

[0089] In the above steps S110 to S130, when there is only one collecting block 511, the response sensitivity in step S110 is the response sensitivity of the collecting block 511 to different components in the gas to be measured at different collecting voltages; the response current in step S120 is the response current of the collecting block 511 at different collecting voltages. When there are multiple collecting blocks 511, the response sensitivity in step S110 is the response sensitivity of each collecting block 511 to different components in the gas to be measured; the response current in step S120 is the response current of each collecting block 511.

[0090] In one embodiment, when there is one collecting block 511, the photoionization measurement method includes the following steps:

[0091] Step S210: respectively obtaining the response sensitivity of the collecting block 511 to different components in the gas to be measured under different collecting voltages.

[0092] Step S220: respectively obtaining the response current of the collector block 511 under different collection voltages.

[0093] Step S230: Calculate and obtain the component concentration information of the gas to be measured according to the response sensitivity of the collecting block 511 to different components in the gas to be measured at different collecting voltages and the response current of the collecting block 511 at different collecting voltages.

[0094] The above steps S210 to S230 are explained by taking the measurement of a mixed gas of benzene and toluene as an example.

[0095] When using Figure 1-Figure 6 When the device of the embodiment shown is used, firstly, a first collecting voltage U1 (collecting voltage is the voltage applied to the collecting electrode 510) is applied between the collecting electrode 510 (a collecting block 511) and the bias electrode 520 by the voltage controller 700. Under the first collecting voltage U1, the benzene ions are completely collected by the collecting electrode 510, while the toluene ions are only partially collected:

[0096] I U1 =k U1 C C6H6 +K U1 C C7H8 (5)

[0097] Among them, I U1 is the response current of the collecting electrode 510 under the first collecting voltage U1, k U1is the response sensitivity of the collecting electrode 510 to benzene under the first collecting voltage U1, K U1 is the response sensitivity of the collecting electrode 510 to toluene at the first collecting voltage U1, C C6H6 is the concentration of benzene in the gas to be tested, C C7H8 is the concentration of toluene in the gas to be tested.

[0098] Then, the voltage of the collecting electrode 510 is adjusted to the second collecting voltage U2 by the voltage controller 700. Under the second collecting voltage U2, both the benzene and toluene ions are completely collected by the collecting electrode 510:

[0099] I U2 =k U2 C C6H6 +K U2 C C7H8 (6)

[0100] Among them, I U2 is the response current of the collection electrode 510 under the second collection voltage U2, k U2 is the response sensitivity of the collecting electrode 510 to benzene under the second collecting voltage U2, K U2 is the response sensitivity of the collecting electrode 510 to toluene under the second collecting voltage U2, C C6H6 is the concentration of benzene in the gas to be tested, C C7H 8 is the concentration of toluene in the gas to be tested.

[0101] In this example, the concentrations of benzene and toluene can be calculated by using equations (5) and (6) respectively.

[0102] In this example, the response sensitivity in step S210 refers to k in formula (5) and formula (6). U1 , K U1 , k U2 and K U2 , k U1 , K U1 , k U2 and K U2 is a known parameter, or can be obtained by prior measurement, experiment or calculation. The response current in step S220 refers to I in formula (5) and formula (6). U1 and I U2 , I U1 and I U2 It can be measured by a current sensor or other detection component during operation. The component concentration information of the gas to be measured in step S230 refers to C in formula (5) and formula (6). C6H6 and C C7H8The first collection voltage U1 and the second collection voltage U2 are known parameters and can be obtained by prior measurement, testing or calculation using formula (4).

[0103] In one embodiment, when there are multiple collecting blocks 511, the photoionization measurement method includes the following steps:

[0104] Step S310: respectively obtaining the response sensitivity of each collecting block 511 to different components in the gas to be measured.

[0105] Step S320: respectively obtain the response current of each collector block 511.

[0106] Step S330: Calculate and obtain the component concentration information of the gas to be measured according to the response sensitivity of each collecting block 511 to different components in the gas to be measured and the response current of each collecting block 511.

[0107] The above steps S310 to S330 are explained by taking the measurement of a mixed gas of benzene and toluene as an example.

[0108] When using Figure 7-Figure 9 In the device of the embodiment shown, the voltage controller 700 controls the collection voltage between the collection electrode 510 and the bias electrode 520 to be constant. The two cations generated after the benzene and toluene in the mixed gas are ionized by the ultraviolet lamp 310 will be captured by the collection electrode 510 (two collection blocks 511), but their response sensitivities are different. The collection block 511 on the left and the collection block 511 on the right satisfy the relationship:

[0109] I 301 =k 301 C C6H6 +K 301 C C7H8 (7)

[0110] I 302 =k 302 C C6H6 +K 302 C C7H8 (8)

[0111] Among them, I 301 is the response current of the collector block 511 on the left, k 301 The response sensitivity of the collector block 511 on the left to benzene, K 301 They are the response sensitivity of the collector block 511 on the left to toluene, C C6H6 is the benzene concentration in the gas to be measured, C C7H8 is the toluene concentration in the gas to be measured, I 302 is the response current of the collector block 511 on the right, k 302 The response sensitivity of the collector block 511 on the right to benzene, K302 The response sensitivity of the collector block 511 on the right to toluene.

[0112] In this example, since the two collecting blocks 511 in the collecting electrode 510 capture part of the benzene and toluene ions respectively, but the capture ratios are different, the number of ions in the gas to be measured will change to different degrees after reaching the collecting block 511 on the right, as shown in k 302 and K 302 Different proportions of changes occur, so the concentrations of benzene and toluene can be calculated respectively by combining equations (7) and (8).

[0113] In this example, the response sensitivity in step S310 refers to k in formula (7) and formula (8): 301 , K 301 , k 302 and K 302 , k 301 , K 301 , k 302 and K 302 is a known parameter and can be obtained by prior measurement, experiment or calculation. The response current in step S320 refers to I in formula (7) and formula (8). 301 and I 302 , I 301 and I 302 It can be measured by a current sensor or other detection component during operation. The component concentration information of the gas to be measured in step S330 refers to C in formula (7) and formula (8). C6H6 and C C7H8 The constant collection voltage controlled by the voltage controller 700 is a known parameter, which can be obtained by prior measurement, experiment or calculation using formula (4).

[0114] In another embodiment, the cross-sectional area of ​​the left collector block 511 can be designed to be large enough to completely capture the benzene ions but only partially capture the toluene ions. In this case, k 302 = 0, benzene has no effect on the measurement of the right collector block 511, and the content of different components in the mixed gas can be measured more easily and better. The cross-sectional area of ​​the left collector block 511 can be calculated by applying formula (4).

[0115] In another embodiment, a larger number of collector blocks 511 can be used to measure more complex mixed gases, for example, Fig.10 The device of the embodiment shown.

[0116] In one embodiment, since humidity is also a gas component in the mixed gas that affects the measurement, in order to effectively compensate for humidity interference, the photoionization measurement method includes the following steps:

[0117] Step S410: respectively obtaining the response sensitivity of each collecting block 511 to different components in the gas to be measured.

[0118] Step S420: respectively obtain the response current of each collector block 511.

[0119] Step S430: respectively obtain the response correction coefficient of each collecting block 511 to the humidity of the gas to be measured.

[0120] Step S440: Calculate and obtain the component concentration information of the gas to be measured according to the humidity value of the gas to be measured, the response sensitivity of each collecting block 511 to different components in the gas to be measured, and the response current of each collecting block 511.

[0121] The above steps S410 to S440 are described by taking the measurement of isobutylene gas as an example.

[0122] When using Fig. 9 The device of the embodiment shown measures isobutylene gas with different humidity, and the voltage controller 700 controls the collection voltage between the collection electrode 510 and the bias electrode 520 to be constant. The response of the left collection block 511 and the right collection block 511 to isobutylene and humidity satisfies the relationship:

[0123] I 301 =k 301 C C4H8 +k 301RH RH (9)

[0124] I 302 =k 302 C C4H8 +k 302RH RH (10)

[0125] Among them, I 301 is the response current of the collector block 511 on the left, k 301 k is the response sensitivity of the collector block 511 on the left to isobutylene, 301RH are the response correction coefficients of the left collector block 511 to humidity, I 302 is the response current of the collector block 511 on the right, k 302 is the response sensitivity of the collector block 511 on the right to isobutylene, k 302RH is the response correction coefficient of the collector block 511 on the right to humidity, RH is the relative humidity of the gas to be measured, C C4H8 is the isobutylene concentration.

[0126] In this example, RH in formula (9) and formula (10) can be a known parameter or an unknown parameter. When RH is an unknown parameter, in this example, the interference of humidity on the measurement can be deducted by the simultaneous equations (9) and (10), and the component concentration information of the gas to be measured can be calculated. When RH is a known parameter or a measurable parameter, in this example, the interference of humidity on the measurement can be deducted by equation (9) or equation (10), and the component concentration information of the gas to be measured can be calculated.

[0127] In this example, the response sensitivity in step S410 refers to k in formula (9) and formula (10): 301 and k 302 , k 301 and k 302 is a known parameter, or can be obtained by prior measurement, experiment or calculation. The response current in step S420 refers to I in formula (9) and formula (10). 301 and I 302 , I 301 and I 302 It can be measured by a current sensor or other detection component during operation. The response correction coefficient in step S430 refers to k in formula (9) and formula (10): 301RH and k 302RH , k 301RH and k 302RH is a known parameter, or can be obtained by prior measurement, testing or calculation. For example, it can be obtained by measuring gases with different humidities in advance and then calculating based on the measured values. The component concentration information of the gas to be measured in step S440 refers to C in formula (9) and formula (10). C4H8 The constant collection voltage controlled by the voltage controller 700 is a known parameter, which can be obtained by prior measurement, experiment or calculation using formula (4).

[0128] In one embodiment, when there is one collecting block 511, the photoionization measurement method includes the following steps:

[0129] Step S510: respectively obtaining the response sensitivity of the collecting block 511 to different components in the gas to be measured when the gas to be measured has different flow rates.

[0130] Step S520: respectively obtaining the response current of the collector block 511 to the gas to be tested at different flow rates.

[0131] Step S530: Calculate the component concentration information of the gas to be measured based on the response sensitivity of the collector block 511 to different components in the gas to be measured at different flow rates and the response current of the collector block 511 at different flow rates of the gas to be measured.

[0132] In the above-mentioned process of step S210 to step S530, the principle is similar to formula (4), formula (5) and formula (6), and the concentration of the component of the gas to be measured can be obtained by simultaneous equations after multiple measurements.

[0133] For example, we can combine the following equations:

[0134] I F1 =k F1 C C6H6 +K F1 C C7H8 (16)

[0135] I F2 =k F2 C C6H6 +K F2 C C7H8 (17)

[0136] Among them C C6H6 is the benzene concentration in the gas to be tested; C C7H8 I is the toluene concentration in the gas to be tested; F1 To collect the response current of the electric block 511 when the gas to be tested at the first flow rate F1 is passed through, k F1 To collect the response sensitivity of the electric block 511 to benzene when the first flow rate F1 of the gas to be tested is introduced, K F1 are respectively the response sensitivity of the collecting block 511 to toluene when the gas to be tested at the first flow rate F1 is introduced, and I F2 To collect the response current of the electric block 511 when the gas to be tested at the first flow rate F2 is introduced, k F2 To collect the response sensitivity of the electric block 511 to benzene when the first flow rate F2 of the gas to be tested is introduced, K F2 They are respectively the response sensitivities of the collecting block 511 to toluene when the gas to be tested at the first flow rate F2 is introduced.

[0137] It should be noted that the above example is for measuring a gas to be measured with known components. When there are unknown components in the gas to be measured, the photoionization measurement method can still measure the specified components of the gas to be measured.

[0138] The following uses Figure 3 The device of the illustrated embodiment adopts the above-mentioned steps S210 to S230, and can analyze the complex mixed gas components by voltage scanning.

[0139] Under different collection voltages, ions of different mass-to-charge ratios are collected by the collection electrode 510 at different collection ratios, that is, under different collection voltages, the collection electrode 510 has different response sensitivities to different ion components in the mixed gas. Thus, one voltage scan is equivalent to performing countless measurements and analyses on the mixed gas. In theory, the components in the mixed gas can be qualitatively and quantitatively analyzed by analyzing the measurement spectrum.

[0140] Determination of measurement parameters of the photoionization measurement device 100: The above analysis shows that under the conditions of the structure of the photoionization measurement device 100 and the gas flow rate, the collection efficiency of ions with different mass-to-charge ratios is different when different collection voltages are used, and the collection efficiency of ions with a small mass-to-charge ratio is higher. There is a characteristic voltage for ions with different mass-to-charge ratios, and at this characteristic voltage, the ions of this component can be completely collected by the collection electrode 510. The characteristic voltages of ions of different gas components can be pre-determined by experiments.

[0141] First, use Figure 3 The device of the illustrated embodiment measures a mixed gas of ethanol, isobutylene, benzene and toluene of known concentrations, and through voltage scanning analysis, characteristic voltages of ethanol, isobutylene, benzene and toluene are obtained as U1, U2, U3 and U4, respectively.

[0142] At the characteristic voltage U1: ethanol ions are completely captured and other ions are partially captured.

[0143] At the characteristic voltage U2: ethanol ions and isobutylene ions are completely captured, and other ions are partially captured.

[0144] At the characteristic voltage U3: ethanol ions, isobutylene ions, and benzene ions are completely captured, and other ions are partially captured.

[0145] At characteristic voltage U4: all four ions are completely captured.

[0146] In the process of qualitative and quantitative analysis of the gas composition of a specific mixed gas, when measuring a single-component gas, under the condition of stable gas flow, the current of the collecting electrode 510 increases with the increase of the voltage. When the characteristic voltage is reached, the current will no longer change. For example, the collection current-collection voltage curve is differentiated, and the obtained measurement curve is differentiated. According to dI / dU=0, the amount of gas components in the mixed gas can be judged, and the characteristic voltage can also be obtained according to dI / dU=0. The applicant can measure U1 through experiments. <U2<U3<U4。

[0147] In the process of actually measuring a mixture of ethanol, isobutene, benzene, and toluene with an unknown concentration, by comparing the characteristic voltages pre-stored in the photoionization measurement device 100, the possible gas components in the mixture are qualitatively judged. For example, when there are no isobutene molecules in the mixture, the characteristic voltage U2 cannot be found in the actually measured spectrogram.

[0148] In one embodiment, during the actual measurement process, through qualitative analysis, it is found that in addition to ethanol, isobutene, benzene, and toluene, there is also an unknown component x in the mixture, and its characteristic voltage is Ux, where U2 < Ux < U3. At this time, in order to accurately measure the benzene concentration, the following measurement mode can be adopted:

[0149] Select three measurement voltages Ux, U3, and U4, and measure the response currents of the collection electrode 510. Ix, I3, and I4 are the response currents at these three collection voltages. Among them:

[0150] Ix: The response current containing all ethanol, isobutene, unknown gas component x, and part of benzene and toluene.

[0151] I3: The response current containing all ethanol, isobutene, unknown gas component x, benzene, and part of toluene.

[0152] (I3 - Ix): Subtracts the interference of all ethanol, isobutene, and unknown gas component x, and contains the response signals of all benzene and part of toluene.

[0153] I4: The response current containing all ethanol, isobutene, unknown gas component x, benzene, and toluene. (I4 - I3): Subtracts the interference of all ethanol, isobutene, unknown gas component x, and benzene, and contains the response current of all toluene.

[0154] Before measuring the gas to be tested, adjust the voltage controller 700, and use benzene standard gas and / or toluene standard gas to measure and calibrate the parameters of the photoionization measurement device 100 at the three collection voltages Ux, U3, and U4 respectively. The parameters of the photoionization measurement device 100 can be calibrated using the following formulas (11), (12), and (13):

[0155] (I3 - Ix) = k 3xC6H6 C C6H6 (11)

[0156] (I3 - Ix) = k 3xC7H8 C C7H8 (12)

[0157] (I4 - I3) = k 43C7H8 C C7H8 (13)

[0158] Among them, C C6H6is the concentration of benzene in the benzene standard gas, C C7H8 is the concentration of toluene in toluene standard gas; k 3xC6H6 , k 3xC7H8 and k 43C7H8 is the response sensitivity of the photoionization measurement device 100 under the present measurement conditions; Ix, I3 and I4 are the response currents obtained at three collection voltages Ux, U3 and U4 respectively after the predetermined standard gas is introduced. And Ix, I3 and I4 in formula (11), formula (12) and formula (13) can be the same or different, and are obtained from different experiments. Formula (11) is an experiment in which benzene standard gas is introduced, and formula (12) and formula (13) are experiments in which toluene standard gas is introduced.

[0159] In formula (11), formula (12) and formula (13), C C6H6 and C C7H8 are known parameters, Ix, I3 and I4 are known numbers measured by passing standard gas, so k can be determined by formula (11), formula (12) and formula (13): 3xC6H6 , k 3xC7H8 and k 43C7H8 The parameters are used to solve the following formulas (14) and (15).

[0160] After calibrating the parameters of the photoionization measuring device 100 using formula (11), formula (12) and formula (13), the voltage controller 700 is adjusted to measure the gas to be measured at three collection voltages Ux, U3 and U4. At this time, the following formula (14) and formula (15) can be used to solve the simultaneous equations to calculate the concentrations of benzene and toluene in the gas to be measured:

[0161] (I3-Ix)=k 3xC6H6 C C6H6 +k 3xC7H8 C C7H8 (14)

[0162] (I4-I3)=0+k 43C7H8 C C7H8 (15)

[0163] Among them, k 3xC6H6 , k 3xC7H8 and k 43C7H8 is the response sensitivity of the photoionization measurement device 100 under the present measurement conditions, is a known parameter calibrated using formula (11), formula (12) and formula (13), C C6H6 and C C7H8 are the concentrations of benzene and toluene in the gas to be tested; Ix, I3 and I4 are the response currents obtained at three collection voltages Ux, U3 and U4 respectively after the gas to be tested is introduced.

[0164] In this example, the response sensitivity in step S110 refers to k in formula (14) and formula (15): 3xC6H6 , k 3xC7H8 and k 43C7H8 The response current in step S120 refers to Ix, I3 and I4 in formula (14) and formula (15). The component concentration information of the gas to be measured in step S230 refers to C in formula (14) and formula (15). C6H6 and C C7H8 .

[0165] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A photoionization measurement device, characterized in that: include: A light emitting component, used for emitting light; An ionization chamber, comprising an ionization cavity for accommodating the gas to be measured, wherein the ionization chamber is configured to allow the light emitted by the light emitting component to enter the ionization cavity, so as to ionize the gas to be measured in the ionization cavity; A measuring chamber, having an outlet channel running through the measuring chamber, wherein the outlet channel is in communication with the ionization chamber so as to allow the ionized gas to flow out; as well as A detection assembly, including a collecting electrode and a bias electrode electrically connected to each other, for detecting the ionized gas to be detected in the outlet channel; The outlet channel is a vertically arranged straight channel, the axial direction of the outlet channel is arranged in the same direction as the light direction emitted by the light emitting component, the outlet channel is provided with a mounting groove arranged around the inner wall of the outlet channel, the collecting electrode is arranged in the mounting groove, the inner wall of the ionization chamber includes the inner top wall of the ionization chamber, the bias electrode is arranged on the inner top wall of the ionization chamber, and a light shielding member is provided between the light emitting component and the bias electrode, for shielding the light irradiated to the surface of the bias electrode; Wherein, the measuring chamber and the light emitting component are respectively located on two sides of the ionization chamber; The bias electrode is provided with at least one first opening for communicating the outlet channel with the ionization chamber.

2. The photoionization measurement device according to claim 1, characterized in that: The bias electrode is an integral structure, the collecting electrode is an integral structure or the collecting electrode includes a plurality of collecting blocks arranged at intervals, and a first isolating member is provided between two adjacent collecting blocks.

3. The photoionization measurement device according to claim 1, characterized in that: Also includes: A voltage controller, electrically connected to the detection component, and used to control the voltage of the detection component; as well as A flow controller is arranged at the outlet channel and is used to control the flow of the gas to be measured.

4. A photoionization measurement method, using the photoionization measurement device according to any one of claims 1 to 3, characterized in that: include: Obtain the response sensitivity of the collecting block to different components in the gas to be tested; Obtaining a response current of the collecting block; The component concentration information of the gas to be measured is calculated based on the response sensitivity of the collecting block to different components in the gas to be measured and the response current of the collecting block.

5. The photoionization measurement method according to claim 4, characterized in that: When the collecting electric block is provided with one, the response sensitivity of the collecting electric block to different components in the gas to be measured at different collecting voltages is obtained respectively; the response current of the collecting electric block at different collecting voltages is obtained respectively, and the component concentration information of the gas to be measured is calculated according to the response sensitivity of the collecting electric block to different components in the gas to be measured at different collecting voltages and the response current of the collecting electric block at different collecting voltages.

6. The photoionization measurement method according to claim 4, characterized in that: When the collecting electric block is provided with one, the response sensitivity of the collecting electric block to different components in the gas to be measured at different flow rates of the gas to be measured is obtained respectively; the response current of the collecting electric block to the gas to be measured at different flow rates is obtained respectively, and the component concentration information of the gas to be measured is calculated according to the response sensitivity of the collecting electric block to different components in the gas to be measured at different flow rates of the gas to be measured and the response current of the collecting electric block to the gas to be measured at different flow rates.

7. The photoionization measurement method according to claim 4, characterized in that: When there are multiple collecting blocks, the response sensitivity of each collecting block to different components in the gas to be measured is obtained respectively; the response current of each collecting block is obtained respectively, and the component concentration information of the gas to be measured is calculated according to the response sensitivity of each collecting block to different components in the gas to be measured and the response current of each collecting block.

8. The photoionization measurement method according to claim 7, characterized in that: Also includes: Obtaining the response correction coefficient of each of the collecting blocks to humidity; The component concentration information of the gas to be measured is calculated based on the response correction coefficient of each of the collecting blocks to humidity, the response sensitivity of the collecting blocks to different components in the gas to be measured and the response current of the collecting blocks.

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