Electrodeless ultraviolet lamp with adjustable luminous intensity and photoionization sensor

Abstract

The utility model provides an electrodeless ultraviolet lamp with adjustable luminous intensity and a photoionization sensor. According to the electrodeless ultraviolet lamp, an ultraviolet lamp tube comprises a glass shell with an opening in one end and an ultraviolet window which is arranged at the opening of the glass shell in a sealed mode so that the inner space of the glass shell can form a closed cavity; the closed cavity is filled with working gas; the driving electrodes are fixedly arranged on the glass shell in a sleeving manner and are arranged at intervals in the axial direction of the glass shell, and the driving electrodes are electrically connected to the driving module; the driving module is used for applying alternating current voltage to each driving electrode pair formed by a plurality of driving electrodes; for the driving electrode pair, one driving electrode is a grounding electrode, the other driving electrode is a high-voltage electrode, and the driving module is used for enabling the grounding electrode to be grounded and applying potential to the high-voltage electrode. The photoionization sensor comprises the electrodeless ultraviolet lamp. According to the ultraviolet lamp for the PID sensor, the problem of large limitation of a luminous intensity adjusting mode of an existing ultraviolet lamp for the PID sensor can be solved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to ultraviolet lamp driving technical field, more specifically, it relates to a kind of light intensity adjustable electrodeless ultraviolet lamp and the photoionization sensor comprising the electrodeless ultraviolet lamp. BACKGROUND

[0002] Photoionization sensor (PID) is usually used to detect organic volatile (VOC) in environment, due to the diversity of detection environment, sometimes, it needs to detect several or several ppb level extremely low concentration VOC, sometimes, it needs to detect several thousand or even ten thousand ppm above high concentration VOC, which requires the range of PID sensor to be large enough, to reach the detection range of 7 orders of magnitude.

[0003] It is known that the process of ionizing VOC molecules of PID sensor during work is a dynamic two-way balance process, that is, while VOC molecules are ionized into VOC ions and electrons, part of VOC ions and electrons recombine into VOC molecules. With the continuous increase of VOC concentration, the ionized VOC molecules also increase, and the collision probability of VOC ions and electrons also increases, at this time, the ionization amount of VOC molecules and VOC gas concentration do not show linear relationship, which is the main reason for the nonlinear output of PID sensor.

[0004] When the concentration of VOC continuously increases, the recombination rate of VOC ions and electrons also continuously increases. When VOC reaches a certain concentration, a large number of ionized VOC ions recombine with electrons before being collected by ion detection electrode, at this time, if the concentration of VOC continues to increase, the collected VOC ions will continue to decrease, at this time, the output signal of PID sensor will no longer increase or even decrease, which is called saturation phenomenon of sensor. The occurrence of this saturation phenomenon is related to the light intensity of vacuum ultraviolet lamp of PID sensor, the structure of ionization chamber and the intensity of bias electric field.

[0005] In practical application, for a PID sensor with specific ionization chamber structure and bias electric field intensity, if you want to improve or eliminate the saturation phenomenon of PID sensor, you can reduce the ionization amount of VOC molecules by reducing the light intensity of ultraviolet lamp. Specifically, the light intensity of ultraviolet lamp is adjustable within a certain range, so that PID sensor can meet the resolution requirement of ppb level in low concentration detection, and saturation phenomenon does not occur in high concentration detection.

[0006] The light intensity adjustment mode of existing ultraviolet lamp for PID sensor mainly includes the following two kinds:

[0007] The first way is to increase the amplitude of the driving voltage or the pulse width frequency to increase the light intensity of the ultraviolet lamp when detecting low concentration, and vice versa when detecting high concentration.

[0008] The second way is to adjust the light intensity of the ultraviolet lamp by modulating the frequency of the driving voltage to improve the detection performance of the PID sensor.

[0009] However, although the above two ways can realize the adjustable light intensity of the ultraviolet lamp for the PID sensor within a certain range, both of the two ways need relatively complex driving circuits to cooperate, and when the driving voltage and the driving frequency are reduced to a certain value, the ultraviolet lamp may not work normally due to the failure to meet the minimum excitation condition of the ultraviolet lamp. Each ultraviolet lamp has a specific threshold of voltage and frequency according to the type and pressure of the working medium filled therein, and when the corresponding threshold is met, the working medium is ionized and broken down. Therefore, the ways of adjusting the light intensity of the ultraviolet lamp by adjusting the amplitude or frequency of the driving voltage have certain limitations. Practical new type content

[0010] The purpose of the present application is to solve the problem of large limitation of the light intensity adjustment mode of the existing ultraviolet lamp for the PID sensor.

[0011] In order to achieve the above purpose, the present application provides a light intensity adjustable electrodeless ultraviolet lamp and a photo-ionization sensor comprising the electrodeless ultraviolet lamp.

[0012] According to the first aspect of the present application, a light intensity adjustable electrodeless ultraviolet lamp is provided, which comprises an ultraviolet lamp tube, a plurality of driving electrodes and a driving module.

[0013] The ultraviolet lamp tube comprises a glass shell with one end open, and an ultraviolet window sealingly arranged at the opening of the glass shell to form a closed chamber in the internal space of the glass shell.

[0014] The closed chamber is filled with working gas.

[0015] The plurality of driving electrodes are fixedly sleeved on the glass shell and arranged along the axial direction of the glass shell, and the plurality of driving electrodes are electrically connected to the driving module.

[0016] The driving module is used to apply an alternating voltage to each driving electrode pair composed of the plurality of driving electrodes.

[0017] For the pair of the driving electrodes, one of the driving electrodes is a ground electrode and the other of the driving electrodes is a high-voltage electrode, the driving module is configured to ground the ground electrode and apply a potential to the high-voltage electrode.

[0018] Optionally, for the plurality of the driving electrodes, one of the driving electrodes is configured to be only available as a high-voltage electrode and the rest of the driving electrodes are all configured to be only available as a ground electrode.

[0019] Optionally, for the plurality of the driving electrodes, one of the driving electrodes is configured to be only available as a ground electrode and the rest of the driving electrodes are all configured to be only available as a high-voltage electrode.

[0020] Optionally, the number of the driving electrodes is even.

[0021] The plurality of the driving electrodes are sequentially divided into pairs of driving electrodes along an arrangement direction.

[0022] For any pair of the driving electrodes, one of the driving electrodes is configured to form a pair of driving electrodes with the other of the driving electrodes.

[0023] Optionally, the driving electrodes are film electrodes formed on an outer wall of the glass housing.

[0024] Alternatively, the driving electrodes are ring electrodes with a predetermined thickness.

[0025] According to a second aspect of the present application, a photo-ionization sensor is provided, which comprises any one of the electrodeless ultraviolet lamps with adjustable light intensity.

[0026] The present application has the following advantages:

[0027] The electrodeless ultraviolet lamp with adjustable light intensity of the present application has the ultraviolet window sealingly arranged at the opening of the glass housing to form an enclosed chamber inside the glass housing for accommodating working gas, and a plurality of driving electrodes are fixedly sleeved on the glass housing and are arranged along the axial direction of the glass housing. The driving module is configured to apply an alternating voltage to each pair of driving electrodes formed by the plurality of driving electrodes.

[0028] For the electrodeless ultraviolet lamp with adjustable light intensity of the present application, the positions of the ionized working gas corresponding to different pairs of driving electrodes in the enclosed chamber are different, i.e., the distances from the center positions of the ionized working gas corresponding to different pairs of driving electrodes to the ultraviolet window are different. At the same time, the volumes of the ionized working gas corresponding to different pairs of driving electrodes can be the same or different.

[0029] When the driving module respectively applies the predetermined voltage to the two driving electrode pairs, if the volumes of the ionized working gas corresponding to the two driving electrode pairs are same, the number of high-energy photons emitted when the plasma formed by the corresponding ionized working gas is quenched is same, but the distances of the photons to the ultraviolet window are different, and the photons are strongly absorbed in the process of passing through the working gas in front of the ultraviolet window, thereby causing the luminous intensity of the electrodeless ultraviolet lamp to be different.

[0030] When the driving module respectively applies the predetermined voltage to the two driving electrode pairs, if the volumes of the ionized working gas corresponding to the two driving electrode pairs are same, the number of high-energy photons emitted when the plasma formed by the corresponding ionized working gas is quenched is same, but the distances of the photons to the ultraviolet window are different, and the photons are strongly absorbed in the process of passing through the working gas in front of the ultraviolet window, thereby causing the luminous intensity of the electrodeless ultraviolet lamp to be different.

[0031] According to the above, for the luminous intensity adjustable electrodeless ultraviolet lamp of the utility model, the luminous intensity of the electrodeless ultraviolet lamp can be adjusted by selecting different driving electrode pairs, and in actual application, different luminous intensity adjustment ranges can be obtained by adjusting the number of driving electrodes and / or the spacing of adjacent two driving electrodes. At the same time, when high concentration detection is carried out, the driving electrode pair corresponding to the distance from the center position of the ionized working gas to the ultraviolet window can be selected to reduce the volume requirement of the ionized working gas, and in this case, even if the applied voltage is very small, the corresponding part of the working gas can be ionized to make the electrodeless ultraviolet lamp output small enough ultraviolet light, thereby effectively avoiding the situation that the ultraviolet lamp cannot work due to insufficient driving voltage in the prior art. Therefore, the luminous intensity adjustable electrodeless ultraviolet lamp of the utility model can effectively solve the problem of large limitation of the luminous intensity adjustment mode of the existing PID sensor ultraviolet lamp.

[0032] The photoionization sensor of the utility model and the luminous intensity adjustable electrodeless ultraviolet lamp belong to one general inventive concept, and at least have the same beneficial effects as the luminous intensity adjustable electrodeless ultraviolet lamp, and the beneficial effects will not be repeated here.

[0033] Other features and advantages of the utility model will be described in detail in the subsequent specific embodiment part. BRIEF DESCRIPTION OF DRAWINGS

[0034] The utility model can be better understood by referring to the description made below in conjunction with the drawings, wherein the same or similar reference signs are used to represent the same or similar parts in all the drawings.

[0035] Figure 1 A principle schematic diagram of the luminous intensity adjustable electrodeless ultraviolet lamp according to the embodiment of the utility model is shown.

[0036] Figure 2 A driving electrode configuration schematic diagram is shown according to an embodiment of the present application;

[0037] Figure 3 Another driving electrode configuration schematic diagram is shown according to an embodiment of the present application;

[0038] Figure 4 Still another driving electrode configuration schematic diagram is shown according to an embodiment of the present application;

[0039] Figure 5 A structure schematic diagram of the electrodeless ultraviolet lamp with adjustable luminous intensity is shown according to an embodiment of the present application, wherein the driving module is not shown;

[0040] Figure 6 A relative position relationship schematic diagram of the driving electrode and the ultraviolet lamp tube is shown according to an embodiment of the present application;

[0041] Figure 7 A relative position relationship schematic diagram of the light shielding shell and the ultraviolet lamp tube is shown according to an embodiment of the present application. DETAILED DESCRIPTION

[0042] In order to enable a person skilled in the art to more fully understand the technical solutions of the present application, in the following, exemplary embodiments of the present application will be described more fully and in detail with reference to the accompanying drawings. Obviously, one or more embodiments of the present application described below are only one or more of the specific manners in which the technical solutions of the present application can be implemented, and are not exhaustive. It should be understood that the technical solutions of the present application can be implemented in other manners belonging to the general inventive concept without creative labor, and should not be limited by the exemplary described embodiments. Based on one or more embodiments of the present application, all other embodiments obtained by a person skilled in the art without creative labor should belong to the scope of protection of the present application.

[0043] Embodiment: Figure 1 A principle schematic diagram of the electrodeless ultraviolet lamp with adjustable luminous intensity is shown according to an embodiment of the present application, wherein the driving electrode is shown in the form of a section, and the two parts opposite to each other constitute a complete driving electrode. Referring to Figure 1 The electrodeless ultraviolet lamp with adjustable luminous intensity according to the embodiment of the present application comprises an ultraviolet lamp tube 100, a plurality of driving electrodes 200 and a driving module 300;

[0044] The ultraviolet lamp tube 100 comprises a glass shell 110 with one end open, and an ultraviolet window 120 sealingly arranged at the opening of the glass shell 110 to form a closed chamber in the internal space of the glass shell 110;

[0045] The closed chamber is filled with working gas;

[0046] The plurality of driving electrodes 200 are fixedly sleeved on the glass shell 110 and arranged along the axial direction of the glass shell 110, and the plurality of driving electrodes 200 are electrically connected to the driving module 300;

[0047] The driving module 300 is configured to apply an alternating voltage to each driving electrode pair formed by the plurality of driving electrodes 200.

[0048] For the driving electrode pair, one of the driving electrodes is a ground electrode and the other of the driving electrodes is a high-voltage electrode, and the driving module 300 is configured to ground the ground electrode and apply a potential to the high-voltage electrode.

[0049] Specifically, in the embodiment of the utility model, the working gas filled in the closed chamber is inert gas or hydrogen isotope; the ultraviolet window 120 is made of crystal material, for example, MgF2 or CaF2, each crystal material has specific cutoff wavelength, for example, the cutoff wavelength of MgF2 crystal is about 117 nanometers, and the ultraviolet photon energy transmitted by the MgF2 crystal window is considered to be 10.6eV.

[0050] Further, in the embodiment of the utility model, the number of driving electrodes 200 is even;

[0051] The plurality of driving electrodes 200 are sequentially divided into a plurality of driving electrode pairs along the arrangement direction.

[0052] For any one of the driving electrode pairs, one of the driving electrodes is configured to form a driving electrode pair only with the other of the driving electrodes.

[0053] Specifically, Figure 2 A driving electrode configuration schematic diagram of the embodiment of the utility model is shown. Referring to Figure 2 In the embodiment of the utility model, the high-voltage electrode A1, the ground electrode A2, the high-voltage electrode A3, the ground electrode A4, the high-voltage electrode A5 and the ground electrode A6 are sequentially and spacedly distributed on the glass shell 110. The high-voltage electrode A1 and the ground electrode A2, the high-voltage electrode A3 and the ground electrode A4, and the high-voltage electrode A5 and the ground electrode A6 respectively form a driving electrode pair. The spacing between the high-voltage electrode A1 and the ground electrode A2, the spacing between the high-voltage electrode A3 and the ground electrode A4, and the spacing between the high-voltage electrode A5 and the ground electrode A6 are all equal, and the spacing between the ground electrode A2 and the high-voltage electrode A3 and the spacing between the ground electrode A4 and the high-voltage electrode A5 are equal.

[0054] When the plasma formed by the ionized working gas is quenched, the number of high-energy photons emitted is the same, but the distance of the photons reaching the ultraviolet window is different. In the process of the photons passing through the front working gas to reach the ultraviolet window, the photons constantly collide with the working gas molecules and are strongly absorbed, thereby causing the light intensity of the electrodeless ultraviolet lamp to be different. Of course, it can be selected that, for the above three driving electrode pairs, only one driving electrode pair can be driven at the same time, any two driving electrode pairs can be driven at the same time, or three electrode pairs can be driven at the same time to meet the required ultraviolet light intensity of the PID sensor.

[0055] Further, as an optional implementation, in the embodiment of the utility model, one of the plurality of driving electrodes 200 is configured to be only used as a ground electrode, and the rest of the driving electrodes are all configured to be only used as high-voltage electrodes.

[0056] Specifically, Figure 3 Another driving electrode configuration schematic diagram of the embodiment of the utility model is shown. Referring to Figure 3 In the embodiment of the utility model, the high-voltage electrode B1, the ground electrode B2 and the high-voltage electrode B3 are sequentially and spacedly distributed on the glass shell 110. When the high-voltage electrode B1 and the ground electrode B2 and the high-voltage electrode B3 and the ground electrode B2 are driven respectively, the number of high-energy photons emitted when the plasma formed by the ionization of the corresponding part of the working gas is quenched is different, and the distance of the photons reaching the ultraviolet window is also different, thereby causing the light intensity of the electrodeless ultraviolet lamp to be different.

[0057] Further, as an optional implementation, in the embodiment of the utility model, one of the plurality of driving electrodes 200 is configured to be only used as a high-voltage electrode, and the rest of the driving electrodes are all configured to be only used as ground electrodes.

[0058] Specifically, Figure 4 Another driving electrode configuration schematic diagram of the embodiment of the utility model is shown. Referring to Figure 4 In the embodiment of the utility model, the high-voltage electrode B1, the ground electrode B2 and the high-voltage electrode B3 are sequentially and spacedly distributed on the glass shell 110. When the high-voltage electrode B1 and the ground electrode B2 and the high-voltage electrode B3 and the ground electrode B2 are driven respectively, the number of high-energy photons emitted when the plasma formed by the ionization of the corresponding part of the working gas is quenched is different, and the distance of the photons reaching the ultraviolet window is also different, thereby causing the light intensity of the electrodeless ultraviolet lamp to be different.

[0059] Further, the driving electrode 200 is a film electrode formed on the outer wall of the glass shell 110.

[0060] Alternatively, the driving electrode 200 is a ring electrode with a predetermined thickness.

[0061] Specifically, the driving electrode 200 can be a film electrode or a ring electrode. Strictly speaking, the film electrode can also be considered as a kind of ring electrode, but it is thinner and is directly formed on the glass shell 110.

[0062] Specifically, Figure 5 A structure diagram of the electrodeless ultraviolet lamp with adjustable light intensity is shown, Figure 6 A relative position relationship diagram of the driving electrode and the ultraviolet lamp tube is shown, Figure 7 A relative position relationship diagram of the light shielding shell and the ultraviolet lamp tube is shown.

[0063] Referring to Figures 5-7 As an optional embodiment, the number of the driving electrodes is three, which are the first driving electrode 210, the second driving electrode 220 and the third driving electrode 230, and the first driving electrode 210, the second driving electrode 220 and the third driving electrode 230 are sequentially distributed between the opening end and the closed end of the glass shell 110; the first driving electrode 210 and the third driving electrode 230 are directly connected with the driving module 300 through the lead-out wire, and the lead-out part is formed on the second driving electrode 220, which is connected with the driving module 300 through the lead wire.

[0064] The first light shielding shell 410 is located at the middle part of the ultraviolet lamp tube 110, the first driving electrode 210 is directly sleeved on the ultraviolet lamp tube 110 and is inserted on the first end of the first light shielding shell 410; the second driving electrode 220 is arranged in the middle annular groove of the first light shielding shell 410 to be indirectly sleeved on the ultraviolet lamp tube 110; the third driving electrode 230 is directly sleeved on the ultraviolet lamp tube 110, the second light shielding shell 420 is located at the closed end of the ultraviolet lamp tube 110, and the two ends of the third driving electrode 230 are respectively connected with the second end of the first light shielding shell 410 and the first end of the second light shielding shell 420 to realize axial fixation. The second end of the second light shielding shell 420 is a relatively contracted circumscribed part, which is inserted and arranged on the corresponding lamp holder.

[0065] Specifically, unlike the prior art which fixedly makes all or most of the working gas in the ultraviolet lamp form plasma to emit light, the embodiments of the present application make the working gas in the predetermined segmented area of the ultraviolet lamp form plasma to emit light, and by reasonably setting the number, distribution position of the driving electrode and the spacing of adjacent electrodes, the electrodeless ultraviolet lamp can emit ultraviolet light of multiple gears and different intensities, thereby meeting the needs of the PID sensor.

[0066] Correspondingly, on the basis of the light-emitting intensity-adjustable electrodeless ultraviolet lamp, the embodiments of the present application further propose a photoionization sensor, which comprises the above light-emitting intensity-adjustable electrodeless ultraviolet lamp.

[0067] Although one or more embodiments of the present application have been described above, it should be understood by those skilled in the art that the present application can be implemented in any other form without departing from the spirit and scope of the present application. Therefore, the above-described embodiments are illustrative rather than limiting, and many modifications and substitutions are obvious to those skilled in the art without departing from the spirit and scope of the present application as defined in the appended claims.

Claims

1. An electrodeless ultraviolet lamp having an adjustable light intensity, characterized by The ultraviolet lamp comprises an ultraviolet lamp tube, a plurality of driving electrodes and a driving module; The ultraviolet lamp tube comprises a glass envelope with one end open, and an ultraviolet window sealingly arranged at the opening of the glass envelope to form a closed chamber in the internal space of the glass envelope; The closed chamber is filled with working gas; The plurality of driving electrodes are each fixedly sleeved on the glass envelope and arranged along the axial direction of the glass envelope at intervals, and each electrically connected to the driving module; The driving module is configured to apply an alternating voltage to each pair of driving electrodes formed by the plurality of driving electrodes; For the pair of driving electrodes, one of the driving electrodes is a ground electrode and the other is a high-voltage electrode, and the driving module is configured to ground the ground electrode and apply a potential to the high-voltage electrode.

2. The intensity-adjustable electrodeless ultraviolet lamp according to claim 1, wherein For the plurality of driving electrodes, one of the driving electrodes is configured to be used only as a high-voltage electrode and the remaining driving electrodes are each configured to be used only as a ground electrode.

3. The intensity-adjustable electrodeless ultraviolet lamp according to claim 1, wherein For the plurality of driving electrodes, one of the driving electrodes is configured to be used only as a ground electrode and the remaining driving electrodes are each configured to be used only as a high-voltage electrode.

4. The intensity-adjustable electrodeless ultraviolet lamp according to claim 1, wherein The number of the driving electrodes is even; The plurality of driving electrodes are sequentially divided into a plurality of pairs of driving electrodes along the arrangement direction; For any pair of driving electrodes, one of the driving electrodes is configured to form a pair of driving electrodes only with the other driving electrode.

5. The intensity adjustable electrodeless ultraviolet lamp according to claim 1, wherein The driving electrode is a film electrode formed on the outer wall of the glass envelope. Alternatively, the driving electrode is a ring electrode with a predetermined thickness.

6. A photoionization sensor characterized by, The ultraviolet lamp comprises an ultraviolet lamp tube, a plurality of driving electrodes and a driving module; The ultraviolet lamp tube comprises a glass envelope with one end open, and an ultraviolet window sealingly arranged at the opening of the glass envelope to form a closed chamber in the internal space of the glass envelope; The closed chamber is filled with working gas; The plurality of driving electrodes are each fixedly sleeved on the glass envelope and arranged along the axial direction of the glass envelope at intervals, and each electrically connected to the driving module; The driving module is configured to apply an alternating voltage to each pair of driving electrodes formed by the plurality of driving electrodes; For the pair of driving electrodes, one of the driving electrodes is a ground electrode and the other is a high-voltage electrode, and the driving module is configured to ground the ground electrode and apply a potential to the high-voltage electrode. For the plurality of driving electrodes, one of the driving electrodes is configured to be used only as a high-voltage electrode and the remaining driving electrodes are each configured to be used only as a ground electrode. For the plurality of driving electrodes, one of the driving electrodes is configured to be used only as a ground electrode and the remaining driving electrodes are each configured to be used only as a high-voltage electrode. The number of the driving electrodes is even; The plurality of driving electrodes are sequentially divided into a plurality of pairs of driving electrodes along the arrangement direction; For any pair of driving electrodes, one of the driving electrodes is configured to form a pair of driving electrodes only with the other driving electrode. The driving electrode is a film electrode formed on the outer wall of the glass envelope. Alternatively, the driving electrode is a ring electrode with a predetermined thickness. The ultraviolet lamp comprises an ultraviolet lamp tube, a plurality of driving electrodes and a driving module; The ultraviolet lamp tube comprises a glass envelope with one end open, and an ultraviolet window sealingly arranged at the opening of the glass envelope to form a closed chamber in the internal space of the glass envelope; The closed chamber is filled with working gas; The plurality of driving electrodes are each fixedly sleeved on the glass envelope and arranged along the axial direction of the glass envelope at intervals, and each electrically connected to the driving module; The driving module is configured to apply an alternating voltage to each pair of driving electrodes formed by the plurality of driving electrodes; For the pair of driving electrodes, one of the driving electrodes is a ground electrode and the other is a high-voltage electrode, and the driving module is configured to ground the ground electrode and apply a potential to the high-voltage electrode.

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