A gas sensor

Abstract

The present application relates to a kind of gas sensor including first shell and second shell, for connecting the grid of first shell and second shell.The grid, the first shell and the second shell jointly define first chamber, several gas sensitive components are provided in the first chamber, at least one target gas can enter the first chamber by the grid;The gas sensor further includes the light emitting component spaced apart by the first shell and the gas sensitive component.Wherein, each gas sensitive component is configured to be able to absorb the target gas entering the first chamber when the light emitted by the light emitting component is irradiated, so as to change resistance value.In this way, the gas sensor can measure multiple target gases, and the integration of gas sensor is improved.

Description

Technical Field

[0001] This invention relates to the field of sensor technology, and specifically to a gas sensor. Background Technology

[0002] The petrochemical industry's production, processing, and transportation equipment contains a wide variety of gases, which may be toxic, flammable, and / or highly polluting. Furthermore, these gases are not necessarily single-type gaseous substances; they may be mixtures of multiple types. If these gases escape into the outside air in large quantities, they can cause environmental pollution or, in severe cases, serious safety accidents. Therefore, it is necessary to monitor these gases in the outside air using gas sensors to enable timely remedial measures in the event of a large leak.

[0003] Currently, although there is considerable research on gas sensors applied to room temperature conditions, most gas sensors can only detect a single type of gas. While multiple sensors can be connected in parallel to form a sensor array to detect multiple gases, issues such as inconsistent interfaces and sizes result in gas sensor arrays that are large in size and have low integration, failing to meet field requirements. Furthermore, at room temperature, the reaction kinetic energy between the gas sensor and the gas is low, leading to drawbacks such as a high detection limit (>10ppm) and a long response time (>60s). Summary of the Invention

[0004] In view of the above-mentioned problems in the prior art, the present invention provides a gas sensor for room temperature conditions that can measure a variety of gases with high integration.

[0005] The technical solution adopted by this invention to solve its technical problem is: to provide a gas sensor, comprising,

[0006] First shell and second shell;

[0007] A grille, used to connect the first housing and the second housing, the grille, the first housing, and the second housing together define a first chamber, the first chamber being provided with a plurality of gas-sensitive elements, and at least one target gas being able to enter the first chamber through the grille; and

[0008] The light-emitting element is arranged at an interval from the gas-sensitive element through the first housing.

[0009] Each of the gas-sensitive elements is configured to adsorb the target gas entering the first chamber when it is irradiated by the light emitted by the light-emitting element, so as to change the resistance value.

[0010] Furthermore, the surface of the first housing located on one side of the first chamber is provided with several areas for housing the gas-sensitive element.

[0011] Furthermore, the various areas are spaced apart, so that the gas-sensitive components are spaced 1mm to 5mm apart.

[0012] Furthermore, the first housing is a columnar structure, and a first sealing plate and a second sealing plate are respectively provided at both ends of the first housing. The first sealing plate and the second sealing plate together define a second chamber within the first housing for mounting the light-emitting element.

[0013] Furthermore, the first sealing plate and / or the second sealing plate are provided with a first contact and a second contact. The first contact is used to connect the gas-sensitive element to the resistance detection circuit, and the second contact is used to connect the light-emitting element to the power supply circuit.

[0014] Furthermore, the first housing is provided with electrode components for arranging the first contact point for connecting the gas-sensitive element to the resistance detection circuit.

[0015] Furthermore, the first and second sealing plates are configured to prevent external light from passing through the first housing and illuminating the gas-sensitive element.

[0016] Furthermore, the region extends along the circumferential direction of the first housing in the axial direction, such that the gas-sensitive elements disposed in each region extend in a spiral direction on the surface of the first housing.

[0017] Furthermore, the first housing is configured to allow light generated by the light-emitting element to illuminate the gas-sensitive element.

[0018] Furthermore, the second housing is configured to prevent external light from passing through the first housing and illuminating the gas-sensitive element.

[0019] Furthermore, the grid is provided with several through holes so that the target gas can pass through the grid and enter the first chamber.

[0020] Furthermore, the wavelength of the light emitted by the light-emitting element is in the range of 100nm to 760nm.

[0021] The beneficial effects of this invention are as follows: A gas sensor provided by this invention includes a first housing, a second housing, and a grid for connecting the first housing and the second housing. The grid, the first housing, and the second housing together define a first chamber, in which a plurality of gas-sensitive elements are disposed. At least one target gas can enter the first chamber through the grid. The gas sensor also includes light-emitting elements arranged at intervals between the gas-sensitive elements and the first housing. Each of the gas-sensitive elements is configured to adsorb the target gas entering the first chamber when illuminated by light emitted from the light-emitting element, thereby changing its resistance value. This allows the gas sensor to measure multiple target gases, improving the integration of the gas sensor.

[0022] Furthermore, the gas sensor uses a first sealing plate, a second sealing plate, and a second housing to prevent external light from shining onto the gas-sensitive element, thus improving the reliability of the gas sensor. Moreover, the first sealing plate, second sealing plate, and second housing ensure that most of the light emitted by the light-emitting element shines onto the gas-sensitive element, improving light utilization and reducing the power consumption of the light-emitting element. In addition, the gas sensor in this invention uses LED beads as the light-emitting element, which is easy to replace and has a lower cost. Attached Figure Description

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0024] Figure 1 The image shows a perspective view of a gas sensor.

[0025] Figure 2 As shown Figure 1 The diagram shows the perspective structure of the gas sensor from a top-down view.

[0026] Figure 3 As shown Figure 1 The diagram shows the perspective structure of the gas sensor viewed from below.

[0027] In the figure, the following reference numerals are used: 100, gas sensor; 10, first housing; 11, first chamber; 12, second chamber; 13, area; 14, gas-sensitive element;

[0028] 20. Second shell;

[0029] 30. Grille; 31. Through hole;

[0030] 40. First sealing plate; 41. First contact; 42. Second contact;

[0031] 50. Second sealing plate; 60. Light-emitting component; 70. Electrode component. Detailed Implementation

[0032] To make the technical problem to be solved, the technical solution, and the beneficial effects of this invention clearer, the invention will now be described in detail with reference to the accompanying drawings. This drawing is a simplified schematic diagram, illustrating only the basic structure of the invention, and therefore only shows the components relevant to the invention. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0033] Example 1

[0034] refer to Figure 1 As shown, a gas sensor 100 provided by the present invention includes a first housing 10, a second housing 20 arranged parallel to the first housing 10, and a grid 30 for connecting the first housing 10 and the second housing 20. The first housing 10 and / or the second housing 20 have several regions 13 on their opposite side surfaces for accommodating gas-sensitive elements 14 made of gas-sensitive material. The grid 30 defines a first chamber 11 between the first housing 10 and the second housing 20. The grid 30 has several through holes 31 to allow air to enter the first chamber 11 through the through holes 31. Once air mixed with one or more target gases enters the first chamber 11, the target gases can alter the physical properties of the corresponding gas-sensitive element 14. By monitoring the physical properties of the gas-sensitive element 14, the target gas can be monitored. The target gas includes substances that are toxic, flammable, and / or highly polluting, existing in gaseous form under target temperature conditions, such as hydrogen sulfide and ammonia. The physical properties include, but are not limited to, conductivity and temperature. The target temperature can be in the range of -5℃ to 35℃.

[0035] Combination Figure 1 As shown, in this embodiment, the gas sensor 100 further includes a plurality of light-emitting elements 60. The plurality of light-emitting elements 60 are configured to emit ultraviolet light and / or visible light under the electrical drive of an external power source. Gas-sensitive elements 14 on a plurality of regions 13 can increase their reactivity with the target gas under the illumination of the light-emitting elements 60, thereby increasing their conductivity. By monitoring the conductivity of the gas-sensitive elements 14, the target gas can be monitored.

[0036] Specifically, when the light emitted by the light-emitting element 60 shines on the gas-sensitive element 14, and the photon energy is the same as the band gap of the gas-sensitive material, the valence band electrons of the gas-sensitive material are excited and cross the band gap to reach the conduction band, thereby forming electron-hole pairs. At this time, the gas-sensitive element 14 will adsorb oxygen molecules after contacting air, forming adsorbed oxygen molecules. The adsorbed oxygen molecules will take electrons from the gas-sensitive element 14 to form O2. -Ions are adsorbed, causing an electron-depleted layer to form on the surface of the gas sensor 14. When the operating temperature of the gas sensor 14 is lower than the predetermined temperature, the adsorbed oxygen molecules mainly function as O2. - O2 exists in ionic form; when the operating temperature of the gas-sensitive element 14 is higher than the predetermined temperature, O2... - Ions continue to steal electrons from gas-sensitive element 14, forming O - Ions. The predetermined temperature is 150°C.

[0037] After the gas-sensitive element 14 comes into contact with the target gas, the target gas is converted into an adsorbed state. The adsorbed target gas reacts with O. - Ionic reaction, simultaneously releasing O - Electrons are released from the ions. The released electrons return to the gas sensor 14, increasing the number of charge carriers on the gas sensor 14 and thus reducing the resistance of the gas sensor 14.

[0038] When the above process reaches equilibrium, the resistance value of the gas sensor 14 remains constant. Once the concentration of the target gas changes, the resistance value of the gas sensor 14 will change until the above process reaches equilibrium again.

[0039] In this embodiment, the percentage change in resistance of the gas-sensitive element 14 relative to its original resistance value is the response sensitivity. This is related to the carrier concentration of the gas-sensitive element 14 and the number of active sites on its surface. The time required for the resistance of the gas-sensitive element 14 to return to another stable value is the response recovery time. This is related to the operating temperature of the gas-sensitive element 14, and the resistance of the gas-sensitive element 14 is affected by the thermal effect of the current on the operating temperature.

[0040] Example 2

[0041] refer to Figure 1-3 As shown, in this embodiment, the first housing 10 has a cylindrical structure, forming a second chamber 12 within it for mounting a plurality of light-emitting elements 60. This separates the light-emitting elements 60 from the target gas entering the first chamber 11 via the first housing 10, preventing the flammable and explosive target gas from burning or exploding due to circuit failure of the light-emitting elements 60, thereby effectively improving the safety of the gas sensor 100. Simultaneously, this also minimizes the heat generated by the current-induced thermal effect of the light-emitting elements 60 from being conducted to the gas-sensitive element 14, thus avoiding affecting the operating temperature of the gas-sensitive element 14.

[0042] In this embodiment, the first housing 10 is made of a transparent material so that the light generated by the light-emitting element 60 can illuminate the gas-sensitive element 14. The first housing 10 can be made of materials such as glass, quartz, and acrylic.

[0043] In this embodiment, a first sealing plate 40 and a second sealing plate 50 are respectively provided at the upper and lower ends of the first housing 10. The first sealing plate 40 and the second sealing plate 50 together define the second chamber 12 within the first housing 10. The first sealing plate 40 and the second sealing plate 50 are made of opaque insulating materials, such as plastic or ceramic. This prevents light emitted from an external light source from shining onto the gas-sensitive element 14, avoiding the influence of external light on the gas-sensitive element 14, thereby ensuring the stability of the gas sensor 100. On the other hand, a plurality of first contacts 41 that contact the gas-sensitive element 14 and a plurality of second contacts 42 that are electrically connected to the light-emitting element 60 can also be provided on the first sealing plate 40 and / or the second sealing plate 50. The plurality of first contacts 41 are used to connect the gas-sensitive elements 14 provided in each region 13 to a resistance detection circuit so as to measure the resistance of the gas-sensitive elements 14 in each region 13. The plurality of second contacts 42 are used to connect each light-emitting element 60 to a power supply circuit so as to supply power to each light-emitting element 60.

[0044] refer to Figure 2 and Figure 3 As shown, in this embodiment, eight regions 13 are provided on the surface of the first housing 10 facing the second housing 20. Each region 13 extends along the axial direction of the first housing 10. Eight gas-sensitive elements 14 made of different gas-sensitive materials can be respectively provided on the eight regions 13. Each of the eight gas-sensitive elements 14 can adsorb one of the target gases, thereby enabling the gas sensor 100 to detect eight different target gases. The regions 13 are spaced 1mm to 5mm apart in the circumferential direction, preferably 1mm to 2mm, to prevent the gas-sensitive elements 14 on each region 13 from contacting each other.

[0045] In this embodiment, the second housing 20 is also a cylindrical structure and is arranged coaxially with the first housing 10. The second housing 20 is also made of an opaque material, such as metal, plastic, or ceramic, to prevent light from external light sources from shining onto the gas-sensitive element 14, thereby ensuring the stability of the gas sensor 100.

[0046] Combination Figure 2 and Figure 3 As shown, in this embodiment, the grille 30 has an annular structure. Two grilles 30 are respectively disposed at both ends of the first housing 10 and the second housing 20 to define a first chamber 11 between the first housing 10 and the second housing 20. The grilles 30 are also made of opaque materials, such as metal, plastic, or ceramic, to prevent light emitted from an external light source from shining onto the gas-sensitive element 14. A through-hole 31 penetrates the grille 30 along its thickness direction to allow gas to enter the first chamber 11.

[0047] Example 3

[0048] In this embodiment, the first housing 10 has a cylindrical structure, forming a second chamber 12 within it for mounting a plurality of light-emitting elements 60. This separates the light-emitting elements 60 from the target gas entering the first chamber 11 via the first housing 10, preventing the flammable and explosive target gas from burning or exploding due to circuit failure of the light-emitting elements 60, thereby effectively improving the safety of the gas sensor 100. Simultaneously, this also minimizes the heat generated by the current-induced thermal effect of the light-emitting elements 60 from being conducted to the gas-sensitive element 14, thus avoiding affecting the operating temperature of the gas-sensitive element 14.

[0049] In this embodiment, the first housing 10 is made of a transparent material so that the light generated by the light-emitting element 60 can illuminate the gas-sensitive element 14. The first housing 10 can be made of materials such as glass, quartz, and acrylic.

[0050] In this embodiment, a first sealing plate 40 and a second sealing plate 50 are respectively provided at the upper and lower ends of the first housing 10. The first sealing plate 40 and the second sealing plate 50 together define the second chamber 12 within the first housing 10. The first sealing plate 40 and the second sealing plate 50 are made of opaque insulating materials, such as plastic or ceramic. This prevents light emitted from an external light source from shining onto the gas-sensitive element 14, avoiding the influence of external light on the gas-sensitive element 14, thereby ensuring the stability of the gas sensor 100.

[0051] In this embodiment, the first housing 10 is provided with electrode components 70 for setting a plurality of first contacts 41 that contact the gas-sensitive components 14. The plurality of first contacts 41 are used to connect the gas-sensitive components 14 disposed on each region 13 to a resistance detection circuit so as to measure the resistance of the gas-sensitive components 14 on each region 13. A plurality of second contacts 42 are used to connect each light-emitting component 60 to a power supply circuit so as to supply power to each light-emitting component 60.

[0052] In this embodiment, eight regions 13 are provided on the surface of the first housing 10 facing the second housing 20. Each region 13 extends axially along the circumferential direction of the first housing 10, so that the gas-sensitive elements 14 on each region 13 extend in a spiral direction on the surface of the first housing 10, thereby increasing the contact area between the gas-sensitive elements 14 on each region 13 and the target gas. Eight gas-sensitive elements 14 made of different gas-sensitive materials can be provided on each of the eight regions 13, and each of the eight gas-sensitive elements 14 can adsorb one of the target gases, thereby enabling the gas sensor 100 to detect eight different target gases. The regions 13 are spaced 1mm to 5mm apart circumferentially, preferably 1mm to 2mm, to prevent the gas-sensitive elements 14 on each region 13 from contacting each other.

[0053] In this embodiment, the second housing 20 is also a cylindrical structure and is arranged coaxially with the first housing 10. The second housing 20 is made of an opaque material, such as metal, plastic, or ceramic, to prevent light from external light sources from shining onto the gas-sensitive element 14, thereby ensuring the stability of the gas sensor 100.

[0054] In this embodiment, the grille 30 has an annular structure. Two grilles 30 are respectively disposed at both ends of the first housing 10 and the second housing 20 to define a first chamber 11 between the first housing 10 and the second housing 20. The grilles 30 are also made of opaque materials, such as metal, plastic, ceramic, etc., to prevent light emitted from external light sources from shining onto the gas-sensitive element 14. The through hole 31 penetrates the grille 30 along its thickness direction to allow gas to enter the first chamber 11.

[0055] Example 4

[0056] In this embodiment, the first housing 10 has a cylindrical structure, forming a second chamber 12 within it for mounting a plurality of light-emitting elements 60. This separates the light-emitting elements 60 from the target gas entering the first chamber 11 via the first housing 10, preventing the flammable and explosive target gas from burning or exploding due to circuit failure of the light-emitting elements 60, thereby effectively improving the safety of the gas sensor 100. Simultaneously, this also minimizes the heat generated by the current-induced thermal effect of the light-emitting elements 60 from being conducted to the gas-sensitive element 14, thus avoiding affecting the operating temperature of the gas-sensitive element 14.

[0057] In this embodiment, the first housing 10 is made of a transparent material so that the light generated by the light-emitting element 60 can illuminate the gas-sensitive element 14. The first housing 10 can be made of materials such as glass, quartz, and acrylic.

[0058] In this embodiment, a first sealing plate 40 and a second sealing plate 50 are respectively provided at the upper and lower ends of the first housing 10. The first sealing plate 40 and the second sealing plate 50 together define the second chamber 12 within the first housing 10. The first sealing plate 40 and the second sealing plate 50 are made of opaque insulating materials, such as plastic or ceramic. This prevents light emitted from an external light source from shining onto the gas-sensitive element 14, avoiding the influence of external light on the gas-sensitive element 14, thereby ensuring the stability of the gas sensor 100.

[0059] In this embodiment, the electrode 70 extends along the axial direction of the first housing 10. Furthermore, a plurality of first contacts 41 extend on the electrode 70 along the axial direction of the first housing 10.

[0060] In this embodiment, several regions 13 are spaced apart along the axial direction on the surface of the first housing 10. Furthermore, each region 13 extends along the circumferential direction of the first housing 10. Gas-sensitive elements 14 made of different gas-sensitive materials can be respectively disposed on the several regions 13, and each gas-sensitive element 14 can adsorb one of the target gases, thereby enabling the gas sensor 100 to detect several types of target gases. This avoids the limitation of the arrangement of each region 13 by a finite circumferential angle, effectively increasing the number of regions 13 and thus increasing the types of target gases that the gas sensor 100 can monitor. Simultaneously, it also allows for a higher integration of the gas sensor 100. The regions 13 are spaced apart by 1mm to 5mm, preferably 1mm to 2mm, in the axial direction, thereby preventing the gas-sensitive elements 14 on each region 13 from contacting each other.

[0061] In this embodiment, the second housing 20 is a cylindrical structure coaxially arranged with the first housing 10. The second housing 20 is made of an opaque material, such as metal, plastic, or ceramic, to prevent light from external light sources from shining onto the gas-sensitive element 14, thereby ensuring the stability of the gas sensor 100.

[0062] In this embodiment, the grille 30 has an annular structure. Two grilles 30 are respectively disposed at both ends of the first housing 10 and the second housing 20 to define a first chamber 11 between the first housing 10 and the second housing 20. The grilles 30 are also made of opaque materials, such as metal, plastic, ceramic, etc., to prevent light from external light sources from shining on the gas-sensitive element 14. The through hole 31 penetrates the grille 30 along its thickness direction to allow gas to enter the first chamber 11.

[0063] Example 5

[0064] In this embodiment, the first housing 10 has a prismatic structure to form a second chamber 12 for mounting a plurality of light-emitting elements 60. This separates the light-emitting elements 60 from the target gas entering the first chamber 11 through the first housing 10, preventing the flammable and explosive target gas from burning or exploding due to circuit failure of the light-emitting elements 60, thereby effectively improving the safety of the gas sensor 100. Simultaneously, this also minimizes the heat generated by the current-induced thermal effect of the light-emitting elements 60 from being conducted to the gas-sensitive element 14, thus avoiding affecting the operating temperature of the gas-sensitive element 14.

[0065] In this embodiment, the first housing 10 is made of a transparent material so that the light generated by the light-emitting element 60 can illuminate the gas-sensitive element 14. The first housing 10 can be made of materials such as glass, quartz, and acrylic.

[0066] In this embodiment, a first sealing plate 40 and a second sealing plate 50 are respectively provided at the upper and lower ends of the first housing 10. The first sealing plate 40 and the second sealing plate 50 together define the second chamber 12 within the first housing 10. The first sealing plate 40 and the second sealing plate 50 are made of opaque insulating materials, such as plastic or ceramic. This prevents light from external light sources from shining on the gas-sensitive element 14, avoiding the influence of external light on the gas-sensitive element 14, thereby ensuring the stability of the gas sensor 100. On the other hand, a plurality of first contacts 41 that contact the gas-sensitive element 14 and a plurality of second contacts 42 that are electrically connected to the light-emitting element 60 can also be provided on the first sealing plate 40 and / or the second sealing plate 50. The plurality of first contacts 41 are used to connect the gas-sensitive element 14 in each region 13 to the resistance detection circuit so as to measure the resistance of the gas-sensitive element 14 in each region 13. The plurality of second contacts 42 are used to connect each light-emitting element 60 to the power supply circuit so as to supply power to each light-emitting element 60.

[0067] In this embodiment, each region 13 can be disposed on a facet of the first housing 10. One, two, or more regions 13 can be disposed on each facet of the first housing 10. Furthermore, each region 13 extends along the axial direction of the first housing 10. Gas-sensitive elements 14 made of different types of gas-sensitive materials can be disposed on several regions 13. Each gas-sensitive element 14 can adsorb one of the target gases, thereby enabling the gas sensor 100 to detect multiple different types of target gases. The regions 13 are spaced 1mm to 5mm apart in the circumferential direction, preferably 1mm to 2mm, to prevent the gas-sensitive elements 14 on each region 13 from contacting each other.

[0068] In this embodiment, the second housing 20 has a prismatic structure and is arranged coaxially with the first housing 10. The second housing 20 is made of an opaque material, such as metal, plastic, or ceramic, to prevent light from external light sources from shining onto the gas-sensitive element 14, thereby ensuring the stability of the gas sensor 100.

[0069] In this embodiment, the grille 30 is a polygonal annular structure. Two grilles 30 are respectively disposed at both ends of the first housing 10 and the second housing 20 to define a first chamber 11 between the first housing 10 and the second housing 20. The grilles 30 are also made of opaque materials, such as metal, plastic, ceramic, etc., to prevent light from external light sources from shining on the gas-sensitive element 14. A through hole 31 penetrates the grille 30 along its thickness direction to allow gas to enter the first chamber 11.

[0070] In the above embodiments, the gas-sensitive material used to manufacture the gas-sensitive element 14 can be a room-temperature hydrogen-sensitive material such as nano-ZnO, TiO2, or SnO2. During preparation, the response performance of the gas-sensitive element 14 at the target temperature can be improved by doping, loading, compositing, or morphology control. Before coating the gas-sensitive material onto each region 13, it must be dispersed in an organic solvent and then ground in a mortar to ensure uniform dispersion of the gas-sensitive material in the organic solvent. The organic solvent can be ethanol, acetone, glycerol, terpineol, etc.

[0071] The ratio of the mass of the organic solvent to the mass of the gas-sensitive material is in the range of 0.1 to 10, preferably 1. This avoids the problem of too much organic solvent, which would prevent the gas-sensitive material from being coated onto region 13, and also avoids the problem of too little organic solvent, which would result in uneven coating of the gas-sensitive material.

[0072] In the above embodiments, the organic solvent containing the gas-sensitive material can be coated onto each region 13 by screen printing or spraying, and then dried to remove the organic solvent and obtain the gas-sensitive element 14. After coating, drying can be carried out at 80°C to 250°C to remove the organic solvent. This avoids the organic solvent evaporating too quickly, which could cause cracks in the gas-sensitive element 14 on region 13, and also avoids the organic solvent evaporating too slowly.

[0073] In the above embodiments, the light-emitting element 60 can be an LED lamp bead, preferably an ultraviolet LED capable of emitting light with a wavelength in the range of 100nm to 400nm, or a visible light LED capable of emitting light with a wavelength in the range of 400nm to 760nm.

[0074] The various light-emitting elements 60 can be electrically connected in series or parallel via wires. Furthermore, the luminous power of each light-emitting element 60 can be adjusted by changing the supply current, thereby meeting the light radiation intensity requirements of different types of gas-sensitive materials.

[0075] In the above embodiments, the light-emitting element 60 can be installed on the portion of the first sealing plate 40 and / or the second sealing plate 50 located in the second chamber 12. This improves the convenience of installing and replacing the light-emitting element 60. On the other hand, it keeps each light-emitting element 60 as far away from the first housing 10 as possible, preventing the heat generated by the light-emitting element 60 when emitting light from being conducted to the first housing 10, thereby avoiding affecting the operating temperature of the gas-sensitive element 14.

[0076] In the above embodiments, the first sealing plate 40 and the second sealing plate 50 can be connected to the first housing 10 in a detachable manner such as snap-fit, bolt-fit, or threaded connection, so as to facilitate replacement after the light-emitting element 60 is damaged.

[0077] In the above embodiment, a waterproof and breathable membrane is also provided at the through-hole 31 of the grille 30. The waterproof and breathable membrane can prevent water vapor and dust from entering the first chamber 11, thereby ensuring the performance of the gas-sensitive element 14 in each area 13.

[0078] In the above embodiments, the surfaces of components such as the first housing 10, the second housing 20, and the grille 30 need to be treated with anti-static agents to prevent the gas sensor 100 from generating sparks during use and entering the flammable target gas in the first chamber 11.

[0079] In some embodiments, the gas sensor 100 provided by the present invention needs to be tested before use, including the following steps.

[0080] In step S1, the power is turned on so that the current passing through the light-emitting element 60 reaches the rated current of the light-emitting element 60, so that the radiation intensity of the light emitted by the light-emitting element 60 reaches a predetermined value.

[0081] In step S2, the gas sensor 100 is placed in clean air, and the first resistance value R of the gas-sensitive element 14 in the i-th region 13 after stabilization is recorded. 1i Where 1≤i≤n and are integers, and n is the total number of regions 13.

[0082] In step S3, a predetermined concentration of the target gas of type i is introduced into the first chamber 11 of the gas sensor 100, and the second resistance value R of the gas-sensitive element 14 corresponding to the target gas of type i is recorded after stabilization. 2i In order to obtain the response sensitivity and response time of the gas sensor 14 on the i-th region 13.

[0083] In some of these implementations, the response sensitivity can be calculated using the following formula (1).

[0084]

[0085] Among them, R 1i R represents the first resistance value of the gas-sensitive element 14 in the i-th region 13 after stabilization, in Ω. 1i The second resistance value of the gas-sensitive element 14 in the i-th region 13 after stabilization, in Ω; M i Let be the response sensitivity of the gas sensor 14 in the i-th region 13, which is dimensionless.

[0086] The response time refers to the time required for the ratio of the change in resistance of the gas-sensitive element 14 to the first resistance value to reach a expected value. For example, when the expected value is equal to 0.9, the response time is |R... 1i -R 2i |R reaching 0.9 times 1i The time required.

[0087] In step S4, steps S2 and S3 are repeated, and the response sensitivity and response time of the gas-sensitive element 14 on each region 13 are input into a preset program so that the gas sensor 100 can identify the n target gases.

[0088] The beneficial effect of the gas sensor 100 provided by the present invention is that it includes a first housing 10 and a second housing 20, and a grid 30 for connecting the first housing 10 and the second housing 20. The grid 30, the first housing 10, and the second housing 20 together define a first chamber 11, in which a plurality of gas-sensitive elements 14 are disposed, and at least one target gas can enter the first chamber 11 through the grid 30. The gas sensor 100 also includes a light-emitting element 60 arranged at intervals between the gas-sensitive elements 14 and the first housing 10. Each gas-sensitive element 14 is configured to adsorb only one type of target gas entering the first chamber 11, and changes its resistance value after being illuminated by light emitted by the light-emitting element 60. This allows the gas sensor 100 to measure multiple target gases, improving the integration of the gas sensor 100.

[0089] Furthermore, the gas sensor 100 prevents external light from shining onto the gas-sensitive element 14 through the first sealing plate 40, the second sealing plate 50, and the second housing 20, thereby improving the reliability of the gas sensor 100. Also, the first sealing plate 40, the second sealing plate 50, and the second housing 20 ensure that most of the light emitted by the light-emitting element 60 shines onto the gas-sensitive element 14, improving light utilization and thus reducing the power consumption of the light-emitting element 60. Moreover, the gas sensor 100 of this invention uses LED beads as the light-emitting element 60, which is easy to replace and has a lower cost.

[0090] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0091] It should be understood that the terms "length", "width", "up", "down", "front and back", "left and right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0092] Although the invention has been described with reference to preferred embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner as long as there is no structural conflict. The invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A gas sensor, comprising, First housing (10) and second housing (20); A grille (30) for connecting the first housing (10) and the second housing (20), the grille (30), the first housing (10), and the second housing (20) together define a first chamber (11), in which a plurality of gas-sensitive elements (14) are disposed, and at least one target gas can enter the first chamber (11) through the grille (30); and The light-emitting element (60) is arranged at a distance from the gas-sensitive element (14) through the first housing (10). in, Each of the gas-sensitive elements (14) is configured to adsorb the target gas entering the first chamber (11) when it is irradiated by light emitted by the light-emitting element (60), so as to change the resistance value.

2. The gas sensor according to claim 1, characterized in that, The surface of the first housing (10) located on one side of the first chamber (11) is provided with several areas (13) for housing the gas-sensitive element (14).

3. The gas sensor according to claim 2, characterized in that, The various regions (13) are arranged at intervals, so that the gas-sensitive components (14) are spaced 1mm to 5mm apart.

4. The gas sensor according to claim 2, characterized in that, The first housing (10) is a columnar structure. A first sealing plate (40) and a second sealing plate (50) are respectively provided at both ends of the first housing (10). The first sealing plate (40) and the second sealing plate (50) together define a second chamber (12) in the first housing (10) for mounting the light-emitting element (60).

5. The gas sensor according to claim 4, characterized in that, The first sealing plate (40) and / or the second sealing plate (50) are provided with a first contact (41) and a second contact (42). The first contact (41) is used to connect the gas-sensitive element (14) to the resistance detection circuit, and the second contact (42) is used to connect the light-emitting element (60) to the power supply circuit.

6. The gas sensor according to claim 4, characterized in that, The first housing (10) is provided with an electrode (70) for arranging the first contact (41) for connecting the gas-sensitive element (14) to the resistance detection circuit.

7. The gas sensor according to claim 4, characterized in that, The first sealing plate (40) and the second sealing plate (50) are configured to prevent external light from passing through the first housing (10) and illuminating the gas-sensitive element (14).

8. The gas sensor according to claim 2, characterized in that, The region (13) extends in the axial direction along the circumferential direction of the first housing (10), such that the gas-sensitive element (14) provided on each region (13) extends in a spiral direction on the surface of the first housing (10).

9. The gas sensor according to any one of claims 1-8, characterized in that, The first housing (10) is configured to allow light generated by the light-emitting element (60) to shine onto the gas-sensitive element (14).

10. The gas sensor according to any one of claims 1-8, characterized in that, The second housing (20) is configured to prevent external light from passing through the first housing (10) and illuminating the gas-sensitive element (14).

11. The gas sensor according to any one of claims 1-8, characterized in that, The grille (30) is provided with a plurality of through holes (31) so that the target gas can pass through the grille (30) and enter the first chamber (11).

12. The gas sensor according to any one of claims 1-8, characterized in that, The wavelength of the light emitted by the light-emitting element (60) is in the range of 100nm to 760nm.

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