Gas sensor with folded light path

Abstract

The utility model relates to a gas sensor with a folded light path. The gas sensor comprises a lower substrate and an upper substrate, an incident collimator, an emergent collimator and at least one reflecting mirror are arranged between the lower substrate and the upper substrate, so that light input by the incident collimator is output from the emergent collimator after being reflected by the reflecting mirror; the upper end face and the lower end face of the reflector are tightly attached to the lower substrate and the upper substrate respectively. The bottom of the incident collimator is fixedly connected with the lower substrate through a first cushion block, and the top of the incident collimator is fixedly connected with the upper substrate through a second cushion block; the bottom of the emergent collimator is fixedly connected with the lower substrate through a third cushion block, and the top of the emergent collimator is fixedly connected with the upper substrate through a fourth cushion block; according to the gas sensor, the whole gas sensor is of a symmetrical structure, the collimator is fixed by the lower substrate and the upper substrate which are arranged in parallel, all optical devices are made of glass materials, the deformation resistance is good, even if deformation occurs, the symmetrical structure can effectively offset the deformation, the temperature stability is improved, and the detection precision is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of optics, in particular to a gas sensor with a folded optical path. Background Art

[0002] Fiber optic gas sensor is a cutting-edge gas detection technology that emerged in the late 1980s. Its outstanding performance characteristics make it stand out among many gas sensors and become the most promising and promising type of sensor. Fiber optic gas sensor has been widely used in environmental monitoring, industrial safety, medical diagnosis and other fields with its ultra-high measurement sensitivity, strong gas identification ability, and fast response speed. In addition, it can effectively resist the interference of environmental factors such as temperature and humidity, ensuring stable and accurate operation in various complex environments.

[0003] The core component of the fiber optic gas sensor is the absorption chamber, whose design is crucial and directly related to the size of the entire sensor and the sensitivity of continuous measurement. In order to ensure the efficient and accurate operation of the sensor, the designer will conduct in-depth research and carefully select the structure and material selection of the absorption chamber.

[0004] In terms of the working principle of the fiber optic gas sensor, it is mainly based on the principle of gas absorption and follows the Beer-Lambert law. When a beam of parallel monochromatic light passes vertically through a uniform and non-scattering light-absorbing material, the degree of light absorption is proportional to the concentration of the material and the thickness of its absorption layer. Specifically in the gas sensor, the gas's absorption rate of light of a specific wavelength depends on the length of the light's path through the gas and the concentration of the gas. As long as the optical path is long enough, the sensor can capture even extremely small concentrations of gas absorption signals, thereby accurately calculating the concentration of the gas.

[0005] Theoretically, in order to achieve high-precision detection at the PPM level, the required optical path length often has to reach several meters or even tens of meters. However, in practical applications, due to the complexity of the on-site environment and the limitations of the detection equipment, the traditional reflected optical path design is often difficult to implement and difficult to meet the needs of online real-time testing. Therefore, the development of an optical path system that can meet the requirements of a longer optical path while maintaining a smaller volume has become an important direction for the development of fiber optic gas sensor technology. Such an optical path system can not only effectively improve the detection capability of the sensor, but also make it more adaptable to various complex and changeable practical application scenarios.

[0006] The Chinese utility model patent with patent announcement number CN203811528U discloses a flat-plate fiber optic gas sensor, including a fiber optic collimator, a front reflector, a rear reflector, and a substrate. The front reflector and the rear reflector are shaped like a cuboid, and have mounting positioning surfaces, which are fixed to the substrate by glue through the positioning surfaces, and the positioning surfaces can be flat. The fiber optic collimator can be directly fixed on the substrate; although the above-mentioned gas sensor increases the optical path length through reflection, which is beneficial to improve the detection accuracy; but this type of plate structure can also be called an optical device product with a single substrate fixing the optical element. Due to the asymmetric structure, the thermal expansion coefficients of the optical elements and the glue used cannot be completely consistent, and bending and deformation will occur at high and low temperatures. Therefore, this single substrate fixing optical element method does not have very good temperature stability. Utility Model Content

[0007] 1. Technical issues to be resolved

[0008] In order to solve the above problems in the prior art, the utility model provides a gas sensor with a folded optical path.

[0009] (II) Technical solution

[0010] In order to achieve the above-mentioned purpose, the main technical solutions adopted by the utility model include:

[0011] A gas sensor with a folded optical path, comprising a lower substrate and an upper substrate; an incident collimator, an output collimator and at least one reflector are arranged between the lower substrate and the upper substrate, so that the input light of the incident collimator is reflected by the reflector and then output from the output collimator; the upper and lower end surfaces of the reflector are respectively tightly fitted with the lower substrate and the upper substrate; the bottom of the incident collimator is fixedly connected with the lower substrate through a first pad; the first pad is tightly fitted with two side walls of the incident collimator, and the bottom surface of the first pad is tightly fitted with the lower substrate; the incident collimator The top is fixedly connected to the upper substrate through a second pad; the second pad is tightly fitted with two side walls of the incident collimator, and the top surface of the second pad is tightly fitted with the upper substrate; the bottom of the output collimator is fixedly connected to the lower substrate through a third pad; the third pad is tightly fitted with two side walls of the output collimator, and the bottom surface of the third pad is tightly fitted with the lower substrate; the top of the output collimator is fixedly connected to the upper substrate through a fourth pad; the fourth pad is tightly fitted with two side walls of the output collimator, and the top surface of the fourth pad is tightly fitted with the upper substrate.

[0012] A gas sensor with a folded optical path comprises a lower substrate and an upper substrate; an incident collimator, an output collimator and at least one reflector are arranged between the lower substrate and the upper substrate, so that the input light of the incident collimator is reflected by the reflector and then output from the incident collimator; the upper and lower end surfaces of the reflector are tightly fitted with the lower substrate and the upper substrate respectively; the bottom of the incident collimator is fixedly connected to the lower substrate through a first pad; the first pad is tightly fitted with two side walls of the incident collimator, and the bottom surface of the first pad is tightly fitted with the lower substrate; the top of the incident collimator is fixedly connected to the upper substrate through a second pad; the second pad is tightly fitted with two side walls of the incident collimator, and the top surface of the second pad is tightly fitted with the upper substrate.

[0013] Furthermore, the contact surfaces of the first pad, the second pad, the third pad and the fourth pad are provided with a dual-curing adhesive so that the incident collimator and the output collimator are stably fixed in the lower substrate and the upper substrate; the contact surface of the reflector is fixed in the lower substrate and the upper substrate using a dual-curing adhesive.

[0014] Furthermore, a second reflector is provided between the incident collimator and the output collimator; the second reflector is arranged opposite to the reflector.

[0015] Furthermore, the reflector is a concave spherical reflector or a plane reflector.

[0016] Furthermore, the second reflector is a concave spherical reflector or a plane reflector.

[0017] Furthermore, the inner side of the cross section of the first cushion block is V-shaped to fit closely with the side walls of the incident collimator; the inner side of the cross section of the second cushion block is inverted V-shaped to fit closely with the side walls of the incident collimator;

[0018] Furthermore, the inner side of the cross section of the third pad is V-shaped to fit tightly with the side walls of the output collimator; the inner side of the cross section of the fourth pad is inverted V-shaped to fit tightly with the side walls of the output collimator.

[0019] Further, the first cushion block includes a first cushion block 1 and a first cushion block 2 having an inclined support surface; the second cushion block includes a second cushion block 1 and a second cushion block 2 having an inclined support surface;

[0020] Furthermore, the third cushion block includes a third cushion block 1 and a third cushion block 2 having an inclined support surface; the fourth cushion block includes a fourth cushion block 1 and a fourth cushion block 2 having an inclined support surface.

[0021] (III) Beneficial effects

[0022] The beneficial effects of the utility model are as follows: the gas sensor has a symmetrical structure as a whole, the collimator is fixed by two parallel lower substrates and upper substrates, each optical device is made of glass material with good deformation resistance, even if deformation occurs, the symmetrical structure can effectively offset the deformation, thereby improving temperature stability and detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solution of the implementation mode of the utility model, the drawings required for use in the implementation mode will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 This is the front view of the structure of the utility model;

[0025] Figure 2 It is a side view of the structure of the utility model;

[0026] Figure 3 It is a top view of the structure of the utility model;

[0027] Figure 4 It is a side view of another embodiment of the structure of the utility model;

[0028] Figure 5 It is a top view of another embodiment of the structure of the utility model;

[0029] Figure 6 It is a top view of another embodiment of the structure of the utility model;

[0030] Description of reference numerals:

[0031] 100, lower substrate; 101, incident collimator; 110, first pad; 111, first pad one; 112, first pad two; 120, second pad; 121, second pad one; 122, second pad two; 200, upper substrate; 201, output collimator; 210, third pad; 211, third pad one, 212, third pad two; 220, fourth pad; 221, fourth pad one; 222, fourth pad two; 300, reflector; 310, second reflector. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the utility model. Therefore, the following detailed description of the embodiments of the utility model provided in the drawings is not intended to limit the scope of the utility model for which protection is sought, but merely represents the selected embodiments of the utility model. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the utility model.

[0033] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "two ends", "one end", "the other end" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0034] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] Example 1, please refer to Figure 1-3 As shown:

[0036] A gas sensor with a folded optical path includes a lower substrate 100 and an upper substrate 200; the lower substrate 100 and the upper substrate 200 are made of glass material or low expansion rate material, and have good anti-deformation ability; the lower substrate 100 and the upper substrate 200 are directly provided with an incident collimator 101, an output collimator 201 and a reflector 300, and the input light of the incident collimator 101 is reflected by the reflector 300 and then output from the output collimator 201, so that a light source is formed between the incident collimator 101 and the reflector 300. The gas chamber can flow freely and unhindered between the lower substrate 100 and the upper substrate 200; the incident collimator 101 and the exit collimator 201 are preferably arranged on the same side, so that a sufficiently long optical path can be provided while reducing the volume; the upper and lower end faces of the reflector 300 are respectively tightly attached to the lower substrate 100 and the upper substrate 200, and a dual-curing adhesive is usually used, and cured by an ultraviolet light source or thermally cured, so as to fix the reflector 300 between the lower substrate 100 and the upper substrate 200;

[0037] The bottom of the incident collimator 101 is fixedly connected to the lower substrate 100 through the first pad 110. The inner side of the cross section of the first pad 110 is V-shaped, so it can be tightly fitted with the two side walls of the cylindrical incident collimator 101. It can also be understood that the two sides of the incident collimator 101 are tightly fitted with the inner side of the first pad 110, and the contact between the two can be understood as line contact. The contact surface of the first pad 110 is fixed to the incident collimator 101 by a dual-curing adhesive, and the bottom surface of the first pad 110 is also fixed by a dual-curing adhesive. The mixture is tightly attached to the top surface of the lower substrate 100; the top of the incident collimator 101 is fixedly connected to the upper substrate 200 through the second pad 120, and the second pad 120 and the first pad 110 are symmetrically arranged relative to the incident collimator 101, so the inner side of the cross section of the second pad 120 is in an inverted V shape, and the two sides of the incident collimator 101 are tightly attached to the inner side of the second pad 120, and are fixed using a dual-curing adhesive, and the top of the second pad 120 is tightly attached to the bottom surface of the upper substrate 200 through the dual-curing adhesive;

[0038] Similarly, the bottom of the output collimator 201 is fixedly connected to the lower substrate 100 via the third pad 210. The inner side of the cross section of the third pad 210 is V-shaped, so it can be tightly fitted with the two side walls of the cylindrical output collimator 201. The contact surface of the third pad 210 is fixed to the output collimator 201 via a dual-curing adhesive, and the bottom surface of the third pad 210 is tightly fitted with the top surface of the lower substrate 100 via the dual-curing adhesive. The top of the collimator 201 is fixedly connected to the upper substrate 200 through the fourth pad 220. The fourth pad 220 and the third pad 210 are symmetrically arranged with respect to the output collimator 201. Therefore, the inner side of the cross section of the fourth pad 220 is an inverted V shape. The two sides of the output collimator 201 are tightly fitted to the inner side of the fourth pad 220 and fixed with a dual-curing adhesive. The top of the fourth pad 220 is tightly fitted to the bottom surface of the upper substrate 200 through the dual-curing adhesive.

[0039] The double substrate fixation makes the overall gas sensor structure symmetrical and highly stable. Since the substrate, collimator, reflector 300, pad and other optical devices are made of glass or low expansion rate materials, they have good deformation resistance and symmetrical structural design, which can effectively offset deformation, thereby improving stability under temperature changes and further improving gas detection accuracy. Figure 1 As shown, a schematic diagram of high and low temperature deformation of an optical device including a dual-substrate fixed optical component of the utility model. When the temperature changes, the optical device will deform. When there are two upper and lower substrates, the deformation of A1 and A2 offset each other or the deformation of B1 and B2 offset each other, so the deformation of the entire optical device is greatly reduced, so it has good temperature stability.

[0040] Embodiment 2, as Figure 4 As shown:

[0041] Compared with the first embodiment, the first pad 110 in this example includes a first pad 111 and a first pad 112 having an inclined supporting surface. Although the combined shape is consistent with the shape of the first pad 110 of the integral structure, it is more convenient to use the first pad 111 and the first pad 112 of the split structure to fix the incident collimator 101 after the position adjustment. It can be inserted from both sides of the incident collimator 101 and fixed, which has higher adjustment flexibility than the first pad 110 of the integral structure; correspondingly, the second pad 120 includes a second pad 121 and a second pad 122 having an inclined supporting surface; the third pad 210 includes a third pad 211 and a third pad 212 having an inclined supporting surface; the fourth pad 220 includes a fourth pad 221 and a fourth pad 222 having an inclined supporting surface.

[0042] Embodiment three, as Figure 5 As shown:

[0043] Compared with the first embodiment, a second reflector 310 is arranged between the incident collimator 101 and the output collimator 201 in this embodiment; the second reflector 310 is arranged opposite to the reflector 300. In this embodiment, the light is reflected more times and has a longer optical path, and the detection accuracy of the gas sensor can be further improved.

[0044] Embodiment 4, as Figure 1 , 6 As shown:

[0045] Compared with the first embodiment, in the present embodiment, only the incident collimator 101 is used. The input light in the incident collimator 101 is reflected by the reflector 300 and then returns to the original path, and is output from the incident collimator 101. The optical path of the present embodiment is shorter than that of the first embodiment, but each air chamber only uses a single optical fiber, the wiring is simpler, and the air chamber structure will also be simpler.

[0046] In another embodiment, the fixing method of the incident collimator 101 may refer to the fixing method of the incident collimator 101 in the second embodiment.

[0047] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent transformations made using the contents of the specification and drawings of the present invention, or directly or indirectly applied in the relevant technical field, are also included in the patent protection scope of the present invention.

Claims

1. A gas sensor with a folded optical path, characterized in that: The invention comprises a lower substrate (100) and an upper substrate (200); an incident collimator (101), an output collimator (201) and at least one reflector (300) are arranged between the lower substrate (100) and the upper substrate (200), so that light input from the incident collimator (101) is reflected by the reflector (300) and then output from the output collimator (201); upper and lower end surfaces of the reflector (300) are respectively tightly fitted to the lower substrate (100) and the upper substrate (200); The bottom of the incident collimator (101) is fixedly connected to the lower substrate (100) via a first pad (110); the first pad (110) is tightly fitted to two side walls of the incident collimator (101), and the bottom surface of the first pad (110) is tightly fitted to the lower substrate (100); the top of the incident collimator (101) is fixedly connected to the upper substrate (200) via a second pad (120); the second pad (120) is tightly fitted to two side walls of the incident collimator (101), and the top surface of the second pad (120) is tightly fitted to the upper substrate (200); The bottom of the output collimator (201) is fixedly connected to the lower substrate (100) via a third pad (210); the third pad (210) is tightly fitted to two side walls of the output collimator (201), and the bottom surface of the third pad (210) is tightly fitted to the lower substrate (100); the top of the output collimator (201) is fixedly connected to the upper substrate (200) via a fourth pad (220); the fourth pad (220) is tightly fitted to two side walls of the output collimator (201), and the top surface of the fourth pad (220) is tightly fitted to the upper substrate (200).

2. A gas sensor with a folded optical path according to claim 1, characterized in that: The contact surfaces of the first pad (110), the second pad (120), the third pad (210), and the fourth pad (220) are all provided with a dual-curing adhesive so that the incident collimator (101) and the output collimator (201) are stably fixed in the lower substrate (100) and the upper substrate (200); the contact surface of the reflector (300) is fixed in the lower substrate (100) and the upper substrate (200) by using the dual-curing adhesive.

3. A gas sensor with a folded optical path according to claim 1, characterized in that: A second reflector (310) is provided between the incident collimator (101) and the output collimator (201); the second reflector (310) is arranged opposite to the reflector (300).

4. A gas sensor with a folded optical path according to claim 1, characterized in that: The reflecting mirror (300) is a concave spherical reflecting mirror (300) or a plane reflecting mirror (300).

5. The gas sensor with folded optical path according to claim 3, characterized in that: The second reflecting mirror (310) is a concave spherical reflecting mirror (300) or a plane reflecting mirror (300).

6. A gas sensor with a folded optical path according to claim 1, characterized in that: The inner side of the cross section of the first cushion block (110) is V-shaped so as to fit tightly with the side walls of the incident collimator (101); and the inner side of the cross section of the second cushion block (120) is inverted V-shaped so as to fit tightly with the side walls of the incident collimator (101).

7. The gas sensor with folded optical path according to claim 1, characterized in that: The inner side of the cross section of the third pad (210) is V-shaped so as to fit tightly with the side walls of the output collimator (201); and the inner side of the cross section of the fourth pad (220) is inverted V-shaped so as to fit tightly with the side walls of the output collimator (201).

8. The gas sensor with folded optical path according to claim 1, characterized in that: The first cushion block (110) comprises a first cushion block 1 (111) and a first cushion block 2 (112) having an inclined support surface; the second cushion block (120) comprises a second cushion block 1 (121) and a second cushion block 2 (122) having an inclined support surface.

9. The gas sensor with folded optical path according to claim 1, characterized in that: The third cushion block (210) comprises a third cushion block 1 (211) and a third cushion block 2 (212) having an inclined support surface; the fourth cushion block (220) comprises a fourth cushion block 1 (221) and a fourth cushion block 2 (222) having an inclined support surface.

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