Gas sensor with adjustable optical sheet

Abstract

The invention provides a gas sensor with an adjustable light sheet, and relates to the technical field of gas sensors, the gas sensor comprises a gas cavity, a light sheet part arranged on one side of the gas cavity and a light source part arranged on one side, far away from the light sheet part, of the gas cavity, and an infrared receiver is arranged on one side, far away from the light source part, of the light sheet part; the light sheet part comprises a light sheet groove and a light filter arranged in the light sheet groove; the optical filter comprises a first substrate, a second substrate, a first functional sheet and a second functional sheet. The first functional sheet is a light film layer with gradually changed thickness; the second functional sheet is provided with a clamping groove used for clamping the optical film sheet. According to the invention, through the modularly mounted combined optical sheet structure, the first functional sheet gradually changes in thickness and the second functional sheet gradually changes in material, so that multiple optical sheet types are formed for infrared filtering when the optical sheets are matched at different angles, different types of gases are effectively detected, and particularly, the measurement efficiency and the detection precision of mixed gases are high.

Description

Technical Field

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

[0002] Non-dispersive infrared (NDIR) gas sensors are a fast and accurate gas analysis technology, especially widely used in continuous emission monitoring systems (CEMS) and motor vehicle exhaust detection applications. They detect the type and concentration of gas by observing the changes in light after the gas is irradiated with infrared light.

[0003] An NDIR gas sensor mainly consists of an inlet, an outlet, an infrared gas detector signal processing circuit, an infrared light source circuit, a gas chamber, an infrared light source, and an infrared gas detector. The infrared gas sensor itself comprises a filter, an infrared detector, a housing, and a base. Infrared light is generated by the infrared light source, passes through the gas chamber and the filter, and is then directed to the infrared detector. According to Beer-Lambert's law, the gas in the gas chamber absorbs different wavelengths of light depending on its type. By measuring the attenuated wavelengths, the gas type and concentration can be determined. The filter is used to eliminate light outside of specific wavelengths (wavelengths that selected gas molecules can absorb).

[0004] This means that the design precision requirements for infrared filters are extremely high. For example, Chinese invention patent CN111596396A discloses an infrared filter, gas sensor, and preparation method for vinyl chloride gas detection. This infrared filter includes a substrate, a main film system, and a cutoff film system, which are formed on opposite sides of the substrate. Both the main film system and the cutoff film system include alternating layers of Ge and SiO films. The main film system has a regular structure, while the cutoff film system has an irregular structure. The above-mentioned invention addresses the problem of the lack of a dedicated infrared filter for vinyl chloride gas detection in the prior art, providing an infrared filter with a center wavelength of 6215±40nm, a passband width of 170±20nm, and a peak transmittance greater than 85%. Furthermore, this infrared filter achieves cutoff regions of 400-6000nm and 6420-11000nm, with a maximum transmittance of less than 0.5% in the cutoff region.

[0005] However, mixed gases collected in special spaces contain many components, and different components of the gas require different filters for effective and accurate detection. Generally, existing NDIR gas sensors only have one type of filter, so a mixed gas may need to be detected multiple times to obtain its component type and concentration, resulting in low detection efficiency.

[0006] Therefore, in order to solve the above problems, it is necessary for us to design a reasonable and efficient dimmable gas sensor. Summary of the Invention

[0007] The purpose of this invention is to provide a tunable light-filter gas sensor. Through a modularly installed combined light-filter structure, the part where the first substrate and the first functional sheet are combined has a gradual change in thickness, and the part where the second substrate and the second functional sheet are combined has a gradual change in material. This allows the first substrate and the second substrate to form various types of light filters for infrared filtering when they are combined at different angles, thereby enabling effective detection of different types of gases, especially high efficiency and high accuracy in measuring mixed gases.

[0008] To achieve the above objectives, the present invention employs the following technical solution:

[0009] A tunable light sheet gas sensor includes a gas cavity, a light sheet portion disposed on one side of the gas cavity, and a light source portion disposed on the side of the gas cavity away from the light sheet portion. An infrared receiver is disposed on the side of the light sheet portion away from the light source portion.

[0010] The light sheet portion includes a light sheet groove and a filter disposed in the light sheet groove; the filter includes a first substrate, a second substrate disposed on the side of the first substrate away from the light source portion, a first functional sheet disposed on the side of the first substrate away from the second substrate, and a second functional sheet disposed on the side of the second substrate away from the first substrate.

[0011] The first functional sheet is a light film layer with a gradually varying thickness;

[0012] The second functional chip is provided with a slot for mounting the optical film.

[0013] As a preferred embodiment of the present invention, the first substrate and the first functional sheet are integrally formed; the second substrate and the second functional sheet are integrally formed.

[0014] As a preferred embodiment of the present invention, a first meshing tooth is provided on the outer side of the first substrate, a second meshing tooth is provided on the outer side of the second substrate, and a first rotating wheel for meshing with the first meshing tooth and a second rotating wheel for meshing with the second meshing tooth are provided on the optical slot.

[0015] As a preferred embodiment of the present invention, the second rotating wheel is an adjustable rotating wheel.

[0016] As a preferred embodiment of the present invention, the second substrate is provided with a functional protrusion on the side near the first substrate, and the first substrate is provided with an annular groove on the side near the second substrate to facilitate the sliding of the functional protrusion.

[0017] In one preferred embodiment of the present invention, the outer diameter of the first substrate is equal to the outer diameter of the second substrate; the outer diameter of the first substrate is larger than the outer diameter of the first functional piece.

[0018] The outer diameter of the first functional piece is equal to the outer diameter of the second functional piece; the inner diameter of the annular groove is not less than the outer diameter of the first functional piece.

[0019] As a preferred embodiment of the present invention, the gas chamber includes a first gas chamber and a second gas chamber, a partition plate is provided between the first gas chamber and the second gas chamber, and a vent pipe for communicating with the first gas chamber and the second gas chamber is provided in the partition plate.

[0020] As a preferred embodiment of the present invention, a light-shielding area is provided in the middle of the second functional piece, and the diameter of the light-shielding area is not less than the thickness of the partition plate.

[0021] As a preferred embodiment of the present invention, the number of card slots is at least two, and the plurality of card slots are evenly arranged around the light-shielding area.

[0022] As a preferred embodiment of the present invention, the optical film layer is an alternating layer of Ge film layer and ZnS film layer, and the optical film sheet is an alternating layer of Ge film layer and ZnS film layer; both the first substrate and the second substrate are single crystal silicon wafers.

[0023] The beneficial effects of the adjustable light sheet gas sensor of the present invention are as follows: through the modularly installed combined light sheet structure, the part where the first substrate and the first functional sheet are combined has a gradual change in thickness, and the part where the second substrate and the second functional sheet are combined has a gradual change in material. This allows multiple types of light sheets to be formed for infrared filtering when the first substrate and the second substrate are combined at different angles, thereby effectively detecting different types of gases, especially with high efficiency and high detection accuracy for mixed gases. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of an embodiment of a dimmable gas sensor according to the present invention;

[0025] Figure 2 This is a side view diagram of the disassembled structure of the filter in one embodiment of a dimmable gas sensor according to the present invention.

[0026] Figure 3 This is a schematic diagram of the structure of the filter in one embodiment of a dimmable gas sensor according to the present invention;

[0027] Figure 4 This is a schematic diagram of the structure of the first substrate and the first functional sheet in one embodiment of a dimmable gas sensor according to the present invention;

[0028] Figure 5 This is a schematic diagram of the structure of the second substrate and the second functional sheet in one embodiment of a dimmable gas sensor according to the present invention;

[0029] Figure 6 This is a schematic diagram of the structure of the second functional piece in one embodiment of a dimmable gas sensor according to the present invention;

[0030] In the figure: 1. Light plate section, 11. Light plate groove, 111. First rotating wheel, 112. Second rotating wheel, 12. Filter, 121. First substrate, 122. Second substrate, 123. First functional plate, 124. First functional plate, 125. Functional protrusion, 126. Annular groove, 127. Slot, 128. Light-shielding area, 2. Light source section, 3. Gas cavity, 31. First gas cavity, 32. Second gas cavity, 33. Partition plate. Detailed Implementation

[0031] The following are specific embodiments of the present invention, which further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0032] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement and steps of the modules and steps set forth in these embodiments do not limit the scope of the invention.

[0033] At the same time, it should be understood that, for ease of description, the process shown in the attached diagram is not performed in isolation, but rather involves multiple steps that overlap.

[0034] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are only for the convenience of describing this invention and simplifying the description, and do not 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 this invention. In addition, the terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0035] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0036] Techniques, methods, and systems known to a person skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the license specification.

[0037] Example 1: As Figures 1 to 6 As shown, this is only one embodiment of the present invention. A tunable light sheet gas sensor includes a gas cavity 3, a light sheet portion 1 disposed on one side of the gas cavity 3, and a light source portion 2 disposed on the side of the gas cavity 3 away from the light sheet portion 1. An infrared receiver is disposed on the side of the light sheet portion 1 away from the light source portion 2.

[0038] In this invention, the gas cavity 3 is transparent, and the light source 2 on one side of the gas cavity 3 emits infrared light. The light first passes through the gas in the gas cavity 3 and then through the light plate 1 before being received by the infrared receiver. The infrared receiver senses the gas data by receiving changes in the light.

[0039] The light plate section 1 includes a light plate groove 11 and a filter 12 disposed in the light plate groove 11; the filter 12 includes a first substrate 121, a second substrate 122 disposed on the side of the first substrate 121 away from the light source section 2, a first functional sheet 123 disposed on the side of the first substrate 121 away from the second substrate 122, and a second functional sheet 124 disposed on the side of the second substrate 122 away from the first substrate 121;

[0040] In this invention, the light plate groove 11 is an annular groove, and the filter 12 is also a circular structure. The filter 12 can be just inserted into the light plate groove 11 to filter infrared light.

[0041] Furthermore, the first substrate 121 and the first functional sheet 123 are integrally formed; the second substrate 122 and the second functional sheet 124 are integrally formed.

[0042] The first substrate 121 and the first functional sheet 123 form the first part of the filter, and the second substrate 122 and the second functional sheet 124 form the second part of the filter. The side of the first substrate 121 near the second substrate 122 and the side of the second substrate 122 near the first substrate 121 are parallel and smoothly arranged, so that the first substrate 121 and the second substrate 122 can be tightly attached together to form an integral substrate. Infrared light filtering is then performed through the integral substrate and the first functional sheets 123 and the second functional sheets 124 on both sides.

[0043] It should be noted that the first functional sheet 123 is a light film layer with a gradually varying thickness; this makes one side of the first functional sheet the thickest and the other side the thinnest, forming a circular light-transmitting sheet with a gradually varying thickness. Moreover, during the process of thickness variation, each variation thickness is half of the previous variation thickness. That is, the variation thickness between the thickest part and the second thickest part is n, then the variation thickness between the second thickest part and the third thickest part is n*1 / 2, the variation thickness between the third thickest part and the fourth thickest part is n*1 / 4, and so on. This allows the infrared light waves to have different variations when passing through the first functional sheet 123 at different thicknesses; where n is the wavelength optical thickness.

[0044] Furthermore, the second functional sheet 124 is provided with a slot 127 for mounting optical films. There are multiple slots 127, each of which is arranged in a fan-shaped structure around the center of the second functional sheet 124. Different optical films can be installed in each slot 127. Each optical film is the same size but different thickness, and each optical film is arranged parallel to the second substrate 122.

[0045] In this invention, the outer side of the first substrate 121 is provided with a first meshing tooth, the outer side of the second substrate 122 is provided with a second meshing tooth, and the optical slot 11 is provided with a first rotating wheel 111 for meshing with the first meshing tooth and a second rotating wheel 112 for meshing with the second meshing tooth.

[0046] When the first rotating wheel 111 rotates, it can engage and drive the first substrate 121 and the first functional piece 123 to rotate, so that the parts of the first functional piece 123 with different thicknesses are aligned with the light source; similarly, when the second rotating wheel 112 rotates, it can engage and drive the second substrate 122 and the second functional piece 124 to rotate, so that the light pattern cards at different positions on the second functional piece 124 are aligned with the light source.

[0047] By rotating the first rotating wheel 111 and the second rotating wheel 112 in sequence, filters of different thicknesses and materials can be used to filter infrared light and detect different gas components in the mixed gas.

[0048] In this invention, the optical film layer is an alternating layer of Ge film layer and ZnS film layer, and the optical film sheet is an alternating layer of Ge film layer and ZnS film layer; the first substrate 121 and the second substrate 122 are both monocrystalline silicon wafers.

[0049] At the first functional piece 123, the transition between the regions with varying thicknesses is an alternating transition between Ge film layers and ZnS film layers; that is, the thickest part and the second thickest part have a Ge film layer with a thickness of n, the second thickest part and the third thickest part have a ZnS film layer with a thickness of n*1 / 2, the third thickest part and the fourth thickest part have a Ge film layer with a thickness of n*1 / 4, and so on.

[0050] The thickness of the Ge film and ZnS film gradually changes alternately, with the thickest part and the third thickest part of the Ge film separated by an interval of n*1 / 4, which is a quarter wavelength optical thickness.

[0051] Example 2, still as Figures 1 to 6 As shown, this is only one embodiment of the present invention. Based on the first embodiment, in the tunable gas sensor of the present invention, the second rotating wheel 112 is an adjustable rotating wheel. In fact, the second rotating wheel 112 has two states: it can be adjusted to engage with the second substrate 122, or it can be adjusted to release the second substrate 122.

[0052] It should be noted that the second substrate 122 is actually detachable and can be removed to replace different optical mode cards for gas detection.

[0053] When the second substrate 122 needs to be removed, the second rotating wheel 112 is adjusted to loosen the second substrate 122, so that the second substrate 122 can be removed. After the new second substrate 122 is installed, the second rotating wheel 112 is adjusted to engage with the second substrate 122 and lock the second substrate 122.

[0054] In this invention, the second substrate 122 is provided with a functional protrusion 125 on the side near the first substrate 121, and the first substrate 121 is provided with an annular groove 126 on the side near the second substrate 122 to facilitate the sliding of the functional protrusion 125. This means that the second substrate 122 and the first substrate 121 can rotate independently, and the functional protrusion 125 of the second substrate 122 can slide in the annular groove 126.

[0055] In this invention, the outer diameter of the first substrate 121 is equal to the outer diameter of the second substrate 122; the outer diameter of the first substrate 121 is greater than the outer diameter of the first functional piece 123; the outer diameter of the first functional piece 123 is equal to the outer diameter of the second functional piece 124; and the inner diameter of the annular groove 126 is not less than the outer diameter of the first functional piece 123.

[0056] Example 3, still as Figures 1 to 6As shown, this is only one embodiment of the present invention. Based on any of the above embodiments, in the tunable gas sensor of the present invention, the gas chamber 3 includes a first gas chamber 31 and a second gas chamber 32. A partition plate 33 is provided between the first gas chamber 31 and the second gas chamber 32. A vent pipe for communicating with the first gas chamber 31 and the second gas chamber 32 is provided in the partition plate 33.

[0057] In other words, one gas can be detected in two gas chambers at the same time. Similarly, gas chamber 3 can be divided into three or even four chambers to detect more gases at the same time.

[0058] In this invention, a light-shielding area 128 is provided in the middle of the second functional piece 124, and the diameter of the light-shielding area 128 is not less than the thickness of the partition plate 33.

[0059] In this invention, the number of card slots 127 is at least two, and the plurality of card slots 127 are evenly arranged around the light-shielding area 128.

[0060] This invention discloses a tunable light-sheet gas sensor with a modularly installed combined light-sheet structure. The portion where the first substrate and the first functional sheet are combined has a gradual change in thickness, and the portion where the second substrate and the second functional sheet are combined has a gradual change in material. This allows the first substrate and the second substrate to form various types of light-sheets for infrared filtering when they are combined at different angles, thereby enabling effective detection of different types of gases, especially high efficiency and high detection accuracy for mixed gases.

[0061] This invention is not limited to the specific embodiments described above, and various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made to the above embodiments based on the technical essence of this invention should be included within the scope of protection of this invention.

Claims

1. A dimmable gas sensor, characterized in that: It includes a gas cavity (3), a light plate part (1) disposed on one side of the gas cavity (3), and a light source part (2) disposed on the side of the gas cavity (3) away from the light plate part (1). An infrared receiver is disposed on the side of the light plate part (1) away from the light source part (2). The light plate section (1) includes a light plate groove (11) and a filter (12) disposed in the light plate groove (11); the filter (12) includes a first substrate (121), a second substrate (122) disposed on the side of the first substrate (121) away from the light source section (2), a first functional sheet (123) disposed on the side of the first substrate (121) away from the second substrate (122), and a second functional sheet (124) disposed on the side of the second substrate (122) away from the first substrate (121); The first functional sheet (123) is a light film layer with a gradually varying thickness; The second functional piece (124) is provided with a slot (127) for mounting the optical film.

2. The dimmable gas sensor according to claim 1, characterized in that: The first substrate (121) and the first functional sheet (123) are integrally formed; the second substrate (122) and the second functional sheet (124) are integrally formed.

3. The dimmable gas sensor according to claim 1, characterized in that: The first substrate (121) has a first meshing tooth on its outer side, and the second substrate (122) has a second meshing tooth on its outer side. The light plate groove (11) is provided with a first rotating wheel (111) for meshing with the first meshing tooth and a second rotating wheel (112) for meshing with the second meshing tooth.

4. A dimmable gas sensor according to claim 3, characterized in that: The second rotating wheel (112) is an adjustable rotating wheel.

5. A dimmable gas sensor according to claim 1, characterized in that: The second substrate (122) has a functional protrusion (125) on the side near the first substrate (121), and the first substrate (121) has an annular groove (126) on the side near the second substrate (122) to facilitate the sliding of the functional protrusion (125).

6. A dimmable gas sensor according to claim 5, characterized in that: The outer diameter of the first substrate (121) is equal to the outer diameter of the second substrate (122); The outer diameter of the first substrate (121) is greater than the outer diameter of the first functional piece (123); the inner diameter of the annular groove (126) is not less than the outer diameter of the first functional piece (123).

7. A dimmable gas sensor according to claim 1, characterized in that: The gas chamber (3) includes a first gas chamber (31) and a second gas chamber (32). A partition plate (33) is provided between the first gas chamber (31) and the second gas chamber (32). A vent pipe for communicating with the first gas chamber (31) and the second gas chamber (32) is provided in the partition plate (33).

8. A dimmable gas sensor according to claim 7, characterized in that: The second functional piece (124) has a light-shielding area (128) in the middle, and the diameter of the light-shielding area (128) is not less than the thickness of the partition plate (33).

9. A dimmable gas sensor according to claim 8, characterized in that: The number of the card slots (127) is at least two, and the plurality of card slots (127) are evenly arranged around the light-shielding area (128).

10. A dimmable gas sensor according to claim 1, characterized in that: The optical film layer is composed of alternating layers of Ge and ZnS films, and the optical film sheet is composed of alternating layers of Ge and ZnS films; the first substrate (121) and the second substrate (122) are both monocrystalline silicon wafers.

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