Ultraviolet lamp for use in photoionization detector

Abstract

The present invention provides an ultraviolet lamp for use in a photoionization detector. The ultraviolet lamp comprises a lamp tube, metal pieces, a sealing layer, and an ultraviolet light window sheet, wherein the lamp tube is filled with an inert working gas, the metal pieces are disposed on the inner wall of the lamp tube, the sealing layer is connected between the lamp tube and the ultraviolet light window sheet so as to maintain the airtightness inside the lamp tube, and the ultraviolet light window sheet allows ultraviolet light, which is generated under the excitation of the inert working gas, to be transmitted and output to the outside. Due to the provision of the metal pieces inside the lamp tube, the ultraviolet lamp helps inert gas molecules therein to be excited more quickly, such that the speed of the ultraviolet lamp entering a working state is significantly increased.

Description

An ultraviolet lamp for use in a photo ionization detector TECHNICAL FIELD

[0001] The present application belongs to the field of detection and analysis, and relates to an ultraviolet lamp for use in a photo ionization detector. BACKGROUND

[0002] A photo ionization detector (PID) is a highly sensitive sensor that utilizes high-energy ultraviolet light to ionize gas molecules for detection. It mainly includes an ultraviolet light source, a sensor chamber, electronic circuits, signal processing and output units, etc. The ultraviolet light source, as the core component of the PID sensor, directly affects the detection ability and accuracy of the detector. Currently, low-voltage electrodeless ultraviolet lamps are commonly used as the ultraviolet light source of detection devices. Electrodeless ultraviolet lamps have the advantages of low power consumption, small size, and easy use, and are widely used in detection devices.

[0003] PID sensors are suitable for detecting volatile organic compounds (VOCs) in environmental protection and industrial safety fields. They have the advantages of small size, rapid response, high measurement accuracy, and can perform continuous and real-time monitoring. At the same time, PID sensors can detect a wide range of VOC concentrations, from extremely low 1 ppb (parts per billion) to as high as tens of thousands of ppm (parts per million). This wide detection range makes PID sensors highly adaptable and flexible in detecting VOCs and other toxic gases under various environmental and industrial conditions. In particular, in the face of disaster accidents, industrial leaks and other emergency situations, PID sensors can quickly detect leaked chemicals, help determine the accident area and leaked substances, and provide critical information for emergency response and accident handling. However, in actual application, it is found that gas detection or analysis devices such as PID sensors and gas chromatographs sometimes cannot quickly excite and enter the normal working state after power-on. There is still a lot of room for improvement in terms of device reliability and detection efficiency.

[0004] Therefore, how to make PID sensors and other devices quickly excite to enter the normal working state after power-on has become an important technical problem for those skilled in the art to solve.

[0005] It should be noted that the above introduction to the technical background is only to facilitate a clear and complete description of the technical solutions of the present application, and to facilitate the understanding of those skilled in the art. The above technical solutions cannot be considered as known to those skilled in the art merely because they are described in the background section of the present application. SUMMARY

[0006] In view of the above-mentioned disadvantages of the prior art, the purpose of the present application is to provide a UV lamp for a photo-ionization detector, which is used to solve the problem that the PID sensor and other devices in the prior art cannot be quickly excited to enter a normal working state after being powered on.

[0007] To achieve the above-mentioned purpose and other related purposes, the present application provides a UV lamp for a photo-ionization detector, which comprises a lamp tube, a metal sheet, a sealing layer and a UV light window sheet, wherein the lamp tube is filled with inert working gas, the metal sheet is arranged on the inner wall of the lamp tube, the sealing layer is connected between the lamp tube and the UV light window sheet to maintain the airtightness of the inside of the lamp tube, and the UV light window sheet allows the UV light generated by the excitation of the inert working gas to pass through.

[0008] Optionally, the metal sheet comprises at least one of a metal material and an alloy of the metal material, wherein the metal material comprises at least one of titanium, zirconium, tantalum, thorium, iron, magnesium, nickel, vanadium, aluminum, barium, gold, silver, copper, tin, lead, zinc, bismuth, cadmium, antimony and rhodium.

[0009] Optionally, the metal sheet is arranged on the inner wall of the lamp tube in at least one of the following ways: the metal sheet is circumferentially abutted on the inner side wall of the lamp tube, the metal sheet is bonded to the inner wall of the lamp tube, and the metal sheet is deposited on the inner wall of the lamp tube.

[0010] Optionally, the metal sheet is bonded to the inner wall of the lamp tube in the form of adhesive bonding, and the adhesive is an inorganic adhesive.

[0011] Optionally, the metal sheet is deposited on the inner wall of the lamp tube in at least one of the following ways: heating melting deposition, chemical reduction deposition and in-situ nano-film deposition, and the heating melting deposition comprises at least one of resistance wire heating, electromagnetic induction heating and direct heating.

[0012] Optionally, the UV lamp comprises only one metal sheet, and the metal sheet is arranged at the middle or tail of the inner wall of the lamp tube.

[0013] Optionally, the UV lamp comprises two metal sheets, and the two metal sheets are arranged separately, and both of the two metal sheets are located at the middle of the inner wall of the lamp tube, or both of the two metal sheets are located at the tail of the inner wall of the lamp tube, or one of the two metal sheets is located at the middle of the inner wall of the lamp tube and the other is located at the tail of the inner wall of the lamp tube.

[0014] Optionally, the ultraviolet lamp is arranged with a pair of driving electrodes, the pair of driving electrodes is arranged on the outer wall of the lamp tube to excite the inert working gas to generate ultraviolet light, and the metal sheet is arranged corresponding to the pair of driving electrodes, wherein the pair of driving electrodes comprises a first electrode and a second electrode, and each metal sheet does not span the area of the inner wall of the lamp tube corresponding to the first electrode and the second electrode.

[0015] Optionally, the metal sheet is located inside the first electrode or inside the second electrode.

[0016] Optionally, when the ultraviolet lamp comprises only one metal sheet, the metal sheet is located inside one of the first electrode and the second electrode; or when the ultraviolet lamp comprises two metal sheets, one metal sheet is located inside one of the first electrode and the second electrode, and the other metal sheet is located inside the other of the first electrode and the second electrode.

[0017] As described above, the ultraviolet lamp for photo-ionization detector of the present application has strong applicability because the metal sheet arranged inside the lamp tube can help the inert gas molecules in the ultraviolet lamp to be excited faster, thereby effectively improving the speed of the ultraviolet lamp entering the working state, and the structure, position and manufacturing method of the metal sheet are various, the overall structure is simple, and it is easy to realize large-scale production. Further, by setting the position and structure of the metal sheet based on the position and setting mode of the pair of driving electrodes used with the ultraviolet lamp, the metal sheet can more strongly sense the electromagnetic field generated by the driving alternating current and play a significant role in the escape and acceleration of electrons in the metal sheet, further improving the speed of the ultraviolet lamp entering the working state. And based on the improvement of the excitation speed of the inert working gas in the ultraviolet lamp, the detection efficiency of the photo-ionization detector equipped with the ultraviolet lamp is effectively improved. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 shows a first simplified structure of the metal sheet in the ultraviolet lamp of the present application in Example 1.

[0019] Figure 2 shows a second simplified structure of the metal sheet in the ultraviolet lamp of the present application in Example 1.

[0020] Figure 3 shows a cross-sectional view along A-A' in Figure 1.

[0021] Figure 4 shows a cross-sectional view along B-B' in Figure 2.

[0022] Figure 5 shows a first simplified structure of the metal sheet in the ultraviolet lamp of the present application in Example 2.

[0023] Fig. 6 shows a simplified schematic diagram of a second simplified structure of the ultraviolet lamp of the present application in Example 2.

[0024] Fig. 7 shows a simplified schematic diagram of the ultraviolet lamp of the present application with a pair of driving electrodes clamped outside.

[0025] Fig. 8 shows a simplified schematic diagram of the ultraviolet lamp of the present application with a pair of driving electrodes sleeved outside.

[0026] Reference numerals 10 lamp 11 inner wall of the lamp 12 outer wall of the lamp 20 metal sheet 30 sealing layer 40 ultraviolet light window sheet 51 first electrode 52 second electrode DETAILED DESCRIPTION

[0027] The present application is described in more detail by the following specific examples. Other advantages and effects of the present application can be easily understood by those skilled in the art from this disclosure. The present application can also be implemented or applied in other different specific embodiments, and each detail in the present specification can be modified or changed based on different views and applications without departing from the spirit of the present application.

[0028] Please refer to Figs. 1 to 8. It is to be noted that the diagrams provided in the present embodiments only schematically illustrate the basic concept of the present application, and thus the diagrams only show the components related to the present application rather than the components number, shape and size when actually implemented. The actual implementation of each component type, number and proportion can be arbitrarily changed, and the component layout type can also be more complicated.

[0029] After analyzing and verifying the problem that the gas detection device including the PID sensor in the background art cannot be quickly excited to enter the normal working state after power-on, it is found that, since the above-mentioned device tends to use a low-voltage electrodeless ultraviolet lamp as an ultraviolet light source, under normal circumstances, the low-voltage electrodeless ultraviolet lamp often needs a certain time to be excited and lit to emit ultraviolet light after an external alternating high voltage is applied, which affects the speed of the detection device entering the working state and the detection efficiency to some extent. The reason for the above problem is that, based on the working principle of the electrodeless ultraviolet lamp, the low-pressure inert gas distributed in the ultraviolet lamp is broken down and forms a plasma state to emit ultraviolet light under the action of alternating high voltage, and the ultraviolet light penetrates the ultraviolet light output window to reach the external environment where the ultraviolet lamp is located. In the process of exciting the inert gas, first, there need to be free charged ions, so that the free charged ions obtain enough energy under the acceleration of the high-voltage electric field to collide with the inert gas molecules to make them decompose into positive and negative ions, and the number of positive and negative ions increases and repeats the above process to excite the whole inert molecules, generate plasma and maintain its state to emit ultraviolet light. However, in the non-working state (without the action of external electric field), the positive and negative ions in the ultraviolet lamp will neutralize each other, resulting in only a few free charged ions in the ultraviolet lamp. When the ultraviolet lamp is powered on (the external electric field is applied), due to the lack of the number of free charged ions, the excitation process of the inert gas molecules in the ultraviolet lamp needs tens of seconds or even minutes, which makes the ultraviolet lamp have a delay after starting and cannot quickly enter the working state, thereby affecting the whole detection device to quickly work.

[0030] Based on the above analysis, the inventors summarize the following technical solution, which shortens the excitation time of the inert gas in the ultraviolet lamp to improve the speed of the ultraviolet lamp entering the working state, and then makes the PID sensor and other devices quickly excited to enter the normal working state after power-on, thereby improving the detection efficiency.

[0031] Embodiment one

[0032] The embodiment provides a kind of ultraviolet lamp (hereinafter referred to as "ultraviolet lamp") for photoionization detector, please refer to figure 1 and figure 2, the ultraviolet lamp includes lamp tube 10, metal sheet 20, sealing layer 30 and ultraviolet light window piece 40.

[0033] Specifically, the lamp tube 10 is filled with inert working gas, the metal sheet 20 is arranged on the inner wall 11 of the lamp tube, the sealing layer 30 is connected between the lamp tube 10 and the ultraviolet light window piece 40 to keep the gas tightness of the lamp tube 10 inside, and the ultraviolet light window piece 40 makes the ultraviolet light excited by the inert working gas to be transmitted.

[0034] As an example, the metal sheet 20 contains at least one of a metal material and an alloy of the metal material, wherein the metal material includes at least one of titanium, zirconium, tantalum, thorium, iron, magnesium, nickel, vanadium, aluminum, barium, gold, silver, copper, tin, lead, zinc, bismuth, cadmium, antimony, and rhodium. It should be noted that the metal material must meet the requirement that its internal electrons are more likely to be detached than the electrons in the inert working gas or glass molecules under the same electromagnetic field environment. Based on this, the inventors have verified from numerous materials that the above-mentioned materials can meet the characteristic requirements. In actual application, the metal material can be selected based on the application scenario and performance requirements of the ultraviolet lamp. If only the requirement of improving the speed of the ultraviolet lamp entering the working state is considered, the metal material with relatively low escape work is preferably used.

[0035] Specifically, the ultraviolet lamp of the present embodiment promotes the speed of the ultraviolet lamp entering the working state by adding a metal sheet to the inner wall of the lamp tube, using the chemical characteristics of the metal material or alloy contained in the metal sheet that is more likely to excite free electrons than inert gas molecules, and making the electrons in the material contained in the metal sheet be detached from the body to become free electrons before the electrons in the inert gas molecules under the same electromagnetic field or microwave action, thereby assisting the inert gas molecules in the ultraviolet lamp to be excited faster.

[0036] As an example, the metal sheet 20 is arranged on the inner wall 11 of the lamp tube in at least one of the following ways: the metal sheet 20 abuts the inner side wall of the lamp tube in the circumferential direction, the metal sheet 20 is bonded to the inner wall 11 of the lamp tube, and the metal sheet 20 is deposited in the inner wall 11 of the lamp tube (the inner wall 11 of the lamp tube includes an inner side wall and an inner bottom wall). Among them, one way of the metal sheet 20 abutting the inner side wall of the lamp tube 10 in the circumferential direction is: according to the size of the inner wall 11 of the lamp tube, a separate metal sheet 20 (in the form of a ring or a ring with an opening) is made outside the lamp tube 10 using a functional material, and then the metal sheet 20 is placed in the lamp tube 10 to abut the inner side wall of the lamp tube 10 by utilizing its own elasticity.

[0037] Further, the way of bonding the metal sheet 20 to the inner wall 11 of the lamp tube is adhesive bonding, and the adhesive is an inorganic adhesive.

[0038] Further, the way of depositing the metal sheet 20 in the inner wall 11 of the lamp tube includes at least one of heating and melting deposition (i.e., using heating to melt the raw material and form a film on the inner wall of the lamp tube), chemical reduction deposition (i.e., attaching a compound powder or slurry containing a functional material to a predetermined area of the inner wall of the lamp tube, and through a reduction reaction, the functional material restores its original properties while being attached to the inner wall of the lamp tube), and In-situ Nano membrane deposition. The way of heating and melting deposition includes at least one of resistance wire heating, electromagnetic induction heating, and direct heating.

[0039] It should be noted that the thickness and coverage area of the metal sheet can be adjusted adaptively based on the application scenario of the ultraviolet lamp, the type of material used by the metal sheet, and the like, and are not specifically limited here.

[0040] As an example, the axial projection of the metal sheet 20 is in an arc shape (as shown in FIG. 3) or a ring shape (as shown in FIG. 4), where "axial" corresponds to the extension direction of the lamp tube 10 (as shown by the dotted line in FIG. 1), "arc shape" means that the metal sheet as a whole is in an arch shape (as shown in FIG. 1), and "ring shape" means that the metal sheet as a whole is in a ring shape (as shown in FIG. 2).

[0041] As an example, the ultraviolet lamp includes only one metal sheet 20, which is arranged at the middle or tail of the inner wall 11 of the lamp tube. For the sake of clarity, "middle" refers to the portion of the inner wall of the lamp tube that is in the middle in the extension direction of the lamp tube (occupying 1 / 3 of the length in the extension direction of the lamp tube), and "tail" refers to the portion of the inner wall of the lamp tube that is on the side of the "middle" away from the ultraviolet light window sheet in the extension direction of the lamp tube. The metal sheet 20 is preferably arranged at the middle of the inner wall 11 of the lamp tube, so that the inert gas discharge is relatively uniformly excited in the entire lamp tube under the action of the electromagnetic field, thereby generating relatively uniform ultraviolet light.

[0042] As an example, the ultraviolet lamp is matched with a pair of driving electrodes for working, the pair of driving electrodes is arranged on the outer wall 12 of the lamp tube to excite the inert working gas to generate ultraviolet light, and the metal sheet 20 is arranged corresponding to the pair of driving electrodes. Each of the metal sheets 20 does not cross the region of the inner wall of the lamp tube corresponding to the first electrode 51 and the second electrode 52, that is, the first electrode is arranged on the portion of the outer wall of the lamp tube corresponding to the first region of the inner wall of the lamp tube, and the second electrode is arranged on the portion of the outer wall of the lamp tube corresponding to the second region of the inner wall of the lamp tube. The metal sheet arranged corresponding to the first electrode can be located in the portion other than the second region, and the metal sheet arranged corresponding to the second electrode can be located in the portion other than the second region.

[0043] Specifically, in this embodiment, the position and structure of the metal sheet are arranged based on the position and arrangement mode of the pair of driving electrodes used in cooperation with the ultraviolet lamp, so that the metal sheet can more strongly induce the electromagnetic field generated by the driving alternating current to play a significant role in the escape and acceleration of electrons in the metal sheet. At the same time, the pair of driving electrodes can also heat the metal sheet to further improve the escape and movement effect of the electrons.

[0044] As an example, the metal sheet 20 is located at the inner side of the first electrode 51 or the inner side of the second electrode 52, where the "inner side" means that the metal sheet 20 is located between the center of the lamp 10 and the corresponding electrode in the radial direction (as shown by the dotted arrow in FIG. 7), for example, please refer to FIG. 7 for understanding, the metal sheet 20 is located between the first electrode 51 and the center of the lamp 10, or the metal sheet 20 is located between the second electrode 51 and the center of the lamp 10. Placing the metal sheet inside the first electrode or the second electrode means that the metal sheet is only arranged corresponding to one of the two electrodes in the radial direction, otherwise the shielding problem of the driving electric field will occur due to the conductive characteristics of the metal sheet itself, and the effect of the metal sheet on improving the inert working gas to be excited faster cannot be achieved, and even it may be counterproductive.

[0045] Further, the arrangement of the driving electrode pair on the outer wall 12 of the lamp includes at least one of being clamped on opposite sides of the outer wall 12 of the lamp (as shown in FIG. 7) and being sleeved on the outer wall 12 of the lamp (as shown in FIG. 8, where the pattern shown by the dotted line is the driving electrode pair). Further, when the driving electrode pair is clamped on the outer wall 12 of the lamp, the metal sheet 20 is preferably arched, and when the driving electrode pair 12 is sleeved on the outer wall of the lamp, the metal sheet 20 is preferably ring-shaped (i.e. the arrangement area of the metal sheet matches the arrangement area of the driving electrode pair), so as to achieve the best matching excitation effect.

[0046] As an example, when the ultraviolet lamp only includes one metal sheet 20, the metal sheet 20 is located at the inner side of one of the first electrode 51 and the second electrode 52 (not shown in the figure, please refer to FIG. 7 and FIG. 8 for understanding).

[0047] As an example, the material of the ultraviolet light window sheet 40 is selected based on actual needs (for example, magnesium fluoride crystal) on the premise of meeting the high transmittance of ultraviolet light generated by the excitation of the inert working gas inside the lamp, at the same time, the material of the lamp 10 is preferably glass material, which has sufficient reliability.

[0048] It should be noted that the ultraviolet lamp can be applied not only to photoionization gas sensors, but also to volatile organic compound gas sensors, gas chromatographs, liquid chromatographs, and ion mobility spectrometers as ultraviolet light sources. When the above-mentioned devices apply the ultraviolet lamp of the present embodiment, the detection efficiency is significantly improved without changing or adjusting the structure of the components and without significantly increasing the cost of the product, which meets the application requirements of the field and scene that requires strict detection efficiency.

[0049] The ultraviolet lamp of the embodiment has strong applicability, because the metal sheet inside the lamp tube helps the inert gas molecules in the ultraviolet lamp to be excited faster, effectively improving the speed of the ultraviolet lamp entering the working state, and the structure, position and manufacturing method of the metal sheet are various, the overall structure is simple, and large-scale production is easy to realize. Further, by setting the position and structure of the metal sheet based on the position and setting method of the driving electrode pair used with the ultraviolet lamp, the metal sheet can more strongly induce the escape and acceleration of electrons in the metal sheet facing the electromagnetic field generated by the driving alternating current, further improving the speed of the ultraviolet lamp entering the working state. Based on the improvement of the excitation speed of the inert working gas in the ultraviolet lamp, the detection efficiency of the photoionization detector equipped with the ultraviolet lamp is effectively improved.

[0050] Embodiment two

[0051] The embodiment provides an ultraviolet lamp (hereinafter referred to as "ultraviolet lamp") for a photoionization detector. The difference between the embodiment and embodiment one is that the ultraviolet lamp in embodiment one only includes one metal sheet, and the ultraviolet lamp in the embodiment includes two metal sheets. Please refer to FIG. 5 and FIG. 6, the ultraviolet lamp includes a lamp tube 10, a metal sheet 20, a sealing layer 30 and an ultraviolet light window piece 40, FIG. 5 and FIG. 6 show two structure schematic diagrams when the ultraviolet lamp has metal sheets with different positions and structures.

[0052] Specifically, the lamp tube 10 is filled with inert working gas, the metal sheet 20 is arranged on the inner wall 11 of the lamp tube, the sealing layer 30 is connected between the lamp tube 10 and the ultraviolet light window piece 40 to maintain the airtightness of the inside of the lamp tube 10, and the ultraviolet light window piece 40 allows the ultraviolet light generated by the excitation of the inert working gas to pass through.

[0053] As an example, the ultraviolet lamp includes two metal sheets 20 which are separately arranged (the "separate arrangement" means that the two metal sheets cannot be connected as a whole), and both of the two metal sheets 20 are located at the middle part of the inner wall 11 of the lamp tube, or both of the two metal sheets 20 are located at the tail part of the inner wall 11 of the lamp tube, or one metal sheet 20 is located at the middle part of the inner wall 11 of the lamp tube and the other metal sheet 20 is located at the tail part of the inner wall 11 of the lamp tube. When the ultraviolet lamp includes two metal sheets 20, the two metal sheets 20 can be made of different materials.

[0054] As an example, the axial projection of the metal sheet 20 is in an arc shape or a ring shape (correspondingly, the metal sheet 20 is in an arch shape or a ring shape as a whole), and the "axial direction" corresponds to the extension direction of the lamp tube 10.

[0055] In an example, when the axial projection of the two metal sheets 20 is in an arc shape (as shown in FIG. 5), the two metal sheets 20 are arranged towards each other in a direction perpendicular to the extension direction of the lamp 10, "arranged towards each other" means that the projections of the two metal sheets 20 in the direction at least partially coincide, at this time, the sizes of the two metal sheets 20 can be the same or different, preferably, the two metal sheets 20 are symmetrically arranged about the central axis of the extension direction of the lamp 10 (i.e., have the same length, width, etc.).

[0056] In another example, when the axial projection of the two metal sheets 20 is in a ring shape (as shown in FIG. 6), the two metal sheets 20 are staggered by a preset distance in the extension direction of the lamp 10, for example, one metal sheet 20 is located at the middle of the inner wall 11 of the lamp, and the other metal sheet 20 is located at the tail of the inner wall 11 of the lamp, or both are located at the middle of the inner wall 11 of the lamp, or both are located at the tail of the inner wall 11 of the lamp, preferably the first distribution, on the one hand, it is convenient for subsequent realization of uniform excitation of the inert working gas in the lamp, on the other hand, it avoids that the time interval with the external alternating high-voltage output device (for example, the driving electrode pair) is too small to affect the reliability.

[0057] As an example, when the ultraviolet lamp includes two metal sheets 20, one metal sheet 20 is located inside one of the first electrode 51 and the second electrode 52, and the other metal sheet 20 is located inside the other of the first electrode 51 and the second electrode 52 (as shown in FIG. 7 and FIG. 8).

[0058] The ultraviolet lamp of the embodiment improves the structure of the metal sheet on the basis of the first embodiment, further improves the speed of the ultraviolet lamp entering the working state, and can realize flexible design of the ultraviolet lamp structure to meet different application requirements.

[0059] In summary, the ultraviolet lamp for photo-ionization detector of the present application can effectively improve the speed of the ultraviolet lamp entering the working state due to the setting of the metal sheet inside the lamp tube to assist the excitation of the inert gas molecules in the ultraviolet lamp, thereby effectively improving the speed of the ultraviolet lamp entering the working state, having strong applicability, and the structure, position and manufacturing method of the metal sheet are various, the overall structure is simple and easy to realize large-scale production. Further, by setting the position and structure of the metal sheet based on the position and setting method of the driving electrode pair used with the ultraviolet lamp, the metal sheet can more strongly induce the escape and acceleration of the electrons in the metal sheet facing the electromagnetic field generated by the driving alternating current, further improving the speed of the ultraviolet lamp entering the working state. And based on the improvement of the excitation speed of the inert working gas in the ultraviolet lamp, the detection efficiency of the photo-ionization detector equipped with the ultraviolet lamp is effectively improved. Therefore, the present application effectively overcomes the shortcomings of the prior art and has high industrial utilization value.

[0060] The above embodiments are only illustrative of the principles and effects of the present application, and are not intended to limit the present application. Any modification or change made by those skilled in the art without departing from the spirit and scope of the present application shall be covered by the claims of the present application.

Claims

1. An ultraviolet lamp for use in a photoionization detector, characterized by: The ultraviolet lamp comprises a lamp tube, a metal sheet, a sealing layer and an ultraviolet light window sheet, wherein the lamp tube is filled with inert working gas, the metal sheet is arranged on the inner wall of the lamp tube, the sealing layer is connected between the lamp tube and the ultraviolet light window sheet to keep the airtightness of the inside of the lamp tube, and the ultraviolet light window sheet allows the ultraviolet light generated by the excitation of the inert working gas to pass through.

2. The ultraviolet lamp of claim 1, wherein: The metal sheet comprises at least one of a metal material and an alloy of the metal material, wherein the metal material comprises at least one of titanium, zirconium, tantalum, thorium, iron, magnesium, nickel, vanadium, aluminum, barium, gold, silver, copper, tin, lead, zinc, bismuth, cadmium, antimony and rhodium.

3. The ultraviolet lamp of claim 1, wherein: The metal sheet is arranged on the inner wall of the lamp tube in at least one of the following ways: the metal sheet abuts the inner wall of the lamp tube in the circumferential direction, the metal sheet is bonded to the inner wall of the lamp tube, and the metal sheet is deposited on the inner wall of the lamp tube.

4. The ultraviolet lamp of claim 3, wherein: The metal sheet is bonded to the inner wall of the lamp tube by means of an adhesive, and the adhesive is an inorganic adhesive.

5. The ultraviolet lamp of claim 3, wherein: The metal sheet is deposited on the inner wall of the lamp tube by at least one of the following methods: heating melting deposition, chemical reduction deposition and in-situ nano film deposition, and the heating melting deposition comprises at least one of resistance wire heating, electromagnetic induction heating and direct heating.

6. The ultraviolet lamp of claim 1, wherein: The ultraviolet lamp comprises only one metal sheet, and the metal sheet is arranged at the middle or tail of the inner wall of the lamp tube.

7. The ultraviolet lamp of claim 1, wherein: The ultraviolet lamp comprises two metal sheets, and the two metal sheets are arranged separately, and both of the two metal sheets are arranged at the middle of the inner wall of the lamp tube, or both of the two metal sheets are arranged at the tail of the inner wall of the lamp tube, or one of the two metal sheets is arranged at the middle of the inner wall of the lamp tube and the other is arranged at the tail of the inner wall of the lamp tube.

8. The ultraviolet lamp according to claim 6 or 7, characterized in that: The ultraviolet lamp is driven by a pair of driving electrodes arranged on the outer wall of the lamp tube to excite the inert working gas to generate ultraviolet light, and the metal sheet is arranged corresponding to the pair of driving electrodes, wherein the pair of driving electrodes comprises a first electrode and a second electrode, and each metal sheet does not cross the area of the inner wall of the lamp tube corresponding to the first electrode and the second electrode.

9. The ultraviolet lamp of claim 1, wherein: The metal sheet is arranged inside the first electrode or inside the second electrode.

10. The ultraviolet lamp of claim 1, wherein: When the ultraviolet lamp comprises only one metal sheet, the metal sheet is arranged inside one of the first electrode and the second electrode; or when the ultraviolet lamp comprises two metal sheets, one of the two metal sheets is arranged inside one of the first electrode and the second electrode, and the other of the two metal sheets is arranged inside the other of the first electrode and the second electrode.

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