Sulfur hexafluoride dual-channel sensor

Abstract

The utility model provides a sulfur hexafluoride dual-channel sensor, relates to the technical field of gas detection, and aims to solve the technical problem that an infrared sulfur hexafluoride sensor is poor in measurement accuracy and stability. Comprising an optical gas chamber, a light source and a detector, the light source and the detector are arranged in the optical gas chamber, the light source and the detector are arranged at the two ends of the optical gas chamber respectively, the optical gas chamber is communicated with the outside, and the light source reflecting surface is located above the light source and used for steering light emitted by the light source; the detector reflecting surface is positioned above the detector and is used for gathering the light rays reflected by the light source reflecting surface onto the detector; the detector reflecting surface comprises a detector reflecting surface I and a detector reflecting surface II, and the detector reflecting surface I and the detector reflecting surface II are symmetrically arranged in parallel. According to the utility model, by designing the light path reflecting surface in the gas chamber, the dual-channel detector can obtain high-efficiency light information, so that the absorption rate of gas to infrared light is improved, and the measurement precision and stability of the sensor are further improved.

Description

Technical Field

[0001] The utility model relates to the technical field of gas detection, in particular to a sulfur hexafluoride dual-channel sensor. Background Art

[0002] Due to its stable gas properties, sulfur hexafluoride is widely used in electrical systems. However, under the action of high-power arc in electrical systems, sulfur hexafluoride is decomposed into chemical substances such as carbon dioxide, sulfur tetrafluoride and fluorine gas, which can damage electrical equipment, seriously cause human poisoning, environmental pollution, greenhouse effect, etc., so the detection of sulfur hexafluoride is particularly important.

[0003] The detection methods of sulfur hexafluoride gas include chromatography, electrochemical method, resistance-capacitance method, infrared method, etc. At present, most of the detection technologies of sulfur hexafluoride infrared method are based on non-dispersive infrared (NDIR) technology, which uses MEMS light source to emit infrared light, which is absorbed by a certain length of gas chamber and then passes through a narrow band filter with a wavelength of 10.6μm. The infrared detector monitors the intensity of the infrared light with a wavelength of 10.6um, and calculates the concentration of sulfur hexafluoride gas.

[0004] There are two main types of air cavity optical paths for infrared sulfur hexafluoride sensors on the market: one is a rectangular parallelepiped with the light source and the detector in opposition, and the other is a rectangular parallelepiped with the light source and the detector in the same measurement. For example, patent publication number CN205192942U discloses an infrared sulfur hexafluoride gas sensor, including a gas chamber body, a double reflecting mirror disposed at one end of the gas chamber body, and an infrared light source and a dual-source dual-complement pyroelectric detector disposed at the other end of the gas chamber body, wherein the infrared light source and the dual-source dual-complement pyroelectric detector are disposed in parallel, and the dual-source dual-complement pyroelectric detector is disposed at the reflection focus of the double reflecting mirror. However, the detectors in current sulfur hexafluoride sensors all have a relatively low receiving efficiency for light, which has a greater impact on the measurement accuracy. Utility Model Content

[0005] In view of the technical problems of poor measurement accuracy and stability of infrared sulfur hexafluoride sensors, the utility model proposes a sulfur hexafluoride dual-channel sensor. By designing the light path reflection surface in the gas chamber, the dual-channel detector can obtain high-efficiency light information, thereby improving the gas's absorption rate of infrared light, and further improving the measurement accuracy and stability of the sensor.

[0006] In order to achieve the above object, the technical solution of the utility model is implemented as follows:

[0007] A sulfur hexafluoride dual-channel sensor, comprising an optical gas chamber, a light source and a detector arranged in the optical gas chamber, wherein the light source and the detector are arranged at two ends of the optical gas chamber respectively, and the optical gas chamber is connected to the outside, and further comprising:

[0008] A light source reflecting surface, located above the light source, for redirecting the light emitted by the light source;

[0009] The detector reflective surface is located above the detector and is used to focus the light reflected by the light source reflective surface onto the detector;

[0010] The detector reflection surface includes a detector reflection surface I and a detector reflection surface II, and the detector reflection surface I and the detector reflection surface II are arranged side by side and symmetrically; the detector includes a detection surface I and a detection surface II;

[0011] The light emitted by the light source is received by the detector after passing through the light source reflection surface and the detector reflection surface, forming a detection light path.

[0012] The light source is a MEMS infrared light source, and the detector is a dual-channel infrared thermopile or a dual-channel pyroelectric sensor. The infrared light emitted by the infrared light source is controlled in an optical gas chamber through which the gas to be measured passes, and the amount of infrared light absorbed (the gas to be measured partially absorbs the radiated infrared light) is measured, thereby achieving the measurement of the concentration of the gas to be measured.

[0013] The optical air chamber comprises a shell, an air inlet is arranged on the shell, and a bottom is arranged on a circuit board and is sealed; the shell and the circuit board form the optical air chamber.

[0014] Preferably, the air inlet is arranged at the top of the shell, perpendicular to the light reflected by the light source reflection surface, so as to reduce the leakage of infrared light, enhance the intensity of the received signal, and reduce the difficulty of detection.

[0015] The air inlet is covered with a waterproof and breathable membrane to prevent impurities such as dust and water vapor from entering the optical air chamber and polluting it.

[0016] The light source and the detector are mounted on a circuit board, a positioning hole is provided on the circuit board, and a positioning piece is provided on the housing, and the positioning piece can be inserted into the positioning hole to position the light source and the detector.

[0017] The light source is arranged at the focal point of the light source reflection surface, and reflects the light emitted by the light source into parallel light, that is, the light source emits infrared light from above the light source reflection surface, and after passing through the light source reflection surface, it is reflected into light parallel to the direction of the line connecting the light source and the detector.

[0018] The detection surface I and the detection surface II are respectively located at the focal points of the detector reflection surface I and the detector reflection surface II. The detector reflection surface I and the detector reflection surface II converge the parallel light into two light beams facing the detection surface I and the detection surface II.

[0019] The detector reflection surface I, the detector reflection surface II and the light source reflection surface are independently selected from any one of an off-axis parabola, a spherical surface or a quadratic surface. The reflection surface determines the convergence point and convergence surface of the parallel light. Its specific structure must meet the requirements of the above-mentioned detection optical path, and is preferably an off-axis parabola.

[0020] The detector reflection surface I, detector reflection surface II and light source reflection surface need to be high-brightness mirror surface and reflective film coated, and are not limited to 24K gold, K gold and other materials that are resistant to oxidation and salt spray and have high reflectivity and low absorption rate for light of the absorption wavelength of sulfur hexafluoride.

[0021] The beneficial effects of the utility model are as follows: on the basis of not changing the volume of the optical gas chamber, the patent adopts an off-axis parabolic reflecting surface through optical path design to make most of the light emitted by the light source become parallel light, and converges most of the light onto the detection surface of the dual-channel detector through two symmetrical off-axis parabolic surfaces, so that most of the light passing through the gas can be detected by the detector, thereby improving the detection rate of the detector, thereby improving the measurement accuracy, resolution and stability of the sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 This is an expanded view of the sulfur hexafluoride sensor of the utility model patent;

[0024] Figure 2 yes Figure 1 Another perspective of the expanded image;

[0025] Figure 3 yes Figure 1 Schematic diagram of the optical path of the sensor.

[0026] In the figure, 1. waterproof breathable membrane; 2. optical air chamber; 21. air inlet; 22. light source reflecting surface; 23. detector reflecting surface I; 24. detector reflecting surface II; 25. positioning member I; 26. positioning member II; 3. circuit board; 31. positioning hole I; 32. positioning hole II; 4. light source; 5. detector; 51. detection surface I; 52. detection surface II. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only 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 creative work are within the scope of protection of the utility model.

[0028] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They 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 direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0029] Example 1

[0030] A sulfur hexafluoride dual-channel sensor, such as Figure 1 and 2 As shown, it includes an optical air chamber 2, a light source 4 and a detector 5 arranged in the optical air chamber 2, the light source 4 and the detector 5 are respectively arranged at two ends of the optical air chamber 2, and the optical air chamber 2 is connected to the outside to enable gas exchange. Specifically, the optical air chamber 2 is a rectangular parallelepiped cavity, and a channel connected to the outside is provided on the cavity, so that the external gas can quickly diffuse into the optical air chamber 2; the light source 4 and the detector 5 are located at two ends of the bottom of the cavity, and a channel for light transmission is formed in the cavity.

[0031] The sensor also includes:

[0032] The light source reflecting surface 22 is located above the light source 4 and is used to redirect the light emitted by the light source 4. By adjusting the shape and position of the light source reflecting surface 22, the light emitted by the light source 4 is transmitted through the channel in the optical air chamber 2 after being redirected, and the circumferential divergence of the light is reduced as much as possible.

[0033] The detector reflection surface is located above the detector 5 and is used to gather the light reflected by the light source reflection surface 22 onto the detector 5. The light source reflection surface 22 mainly plays the role of focusing and redirecting. When the light passing through the optical air chamber 2 is irradiated to the detector 5 reflection surface, the light can be reflected onto the detector 5 and collected at the detector 5, thereby improving the light receiving efficiency;

[0034] The detector reflection surface includes a detector reflection surface I23 and a detector reflection surface II24, which are arranged side by side and symmetrically; the detector 5 includes a detection surface I51 and a detection surface II52; after the light is reflected by the detector reflection surface I23 and the detector reflection surface II24, two mutually parallel light channels are formed, and are respectively received by the detection surface I51 and the detection surface II52. One channel is used as a measurement channel, and the other channel is used as a reference channel. After using the reference channel, the measurement error caused by dust or radiation intensity attenuation can be eliminated.

[0035] The optical path diagram of this embodiment is as follows Figure 3 As shown, the light emitted by the light source 4 is received by the detector 5 after passing through the light source reflection surface 22 and the detector reflection surface, forming a detection light path.

[0036] Example 2

[0037] A sulfur hexafluoride dual-channel sensor, such as Figure 1 and 2 As shown, it includes an optical air chamber 2, a light source 4 and a detector 5 arranged in the optical air chamber 2, the light source 4 and the detector 5 are respectively arranged at two ends of the optical air chamber 2, and the optical air chamber 2 is connected to the outside, and also includes: a light source reflection surface 22, located above the light source 4, for deflecting the light emitted by the light source 4; a detector reflection surface, located above the detector 5, for focusing the light reflected by the light source reflection surface 22 onto the detector 5; the detector reflection surface includes a detector reflection surface I23 and a detector reflection surface II24, and the detector reflection surface I23 and the detector reflection surface II24 are symmetrically arranged side by side; the detector 5 includes a detection surface I51 and a detection surface II52.

[0038] The light source 4 is a MEMS infrared light source, and the detector 5 is a dual-channel infrared thermopile or a dual-channel pyroelectric sensor. The infrared light emitted by the infrared light source 4 is controlled in the optical gas chamber 2 through which the gas to be measured passes, and the amount of infrared light absorbed is measured (the gas to be measured partially absorbs the radiated infrared light), thereby achieving the measurement of the concentration of the gas to be measured.

[0039] Specifically,

[0040] The optical air chamber 2 comprises a shell, an air inlet 21 is provided on the shell, and the bottom is provided on the circuit board 3 and sealed; the shell and the circuit board 3 enclose the optical air chamber 2. Preferably, the air inlet 21 is provided on the top of the shell, perpendicular to the light reflected by the reflection surface 22 of the light source 4, so as to reduce the leakage of infrared light, enhance the strength of the received signal, and reduce the difficulty of detection.

[0041] The air inlet 21 is covered with a waterproof breathable membrane 1 to prevent dust, water vapor and other impurities from entering the optical air chamber 2 and polluting it.

[0042] The light source 4 and the detector 5 are installed on the circuit board 3 to control the light source 4 and the detector 5; the circuit board 3 is provided with positioning holes, which include positioning holes I31 and positioning holes II32, and the positioning holes I31 and the positioning holes II32 are respectively located at the two ends of the circuit board 3, and the shell is provided with positioning parts, which include positioning parts I25 and positioning parts II26, and the positioning holes I31 and the positioning holes II32 are respectively matched with the positioning parts I25 and the positioning parts II26, that is, the positioning parts can be inserted into the positioning holes to position the light source 4 and the detector 5.

[0043] The light source 4 is located directly above the light source reflecting surface 22 and is set at the focal point of the light source reflecting surface 22 to reflect the light emitted by the light source 4 as parallel light, that is, the light source 4 emits infrared light from above the light source reflecting surface 22, which is reflected by the light source reflecting surface 22 as light parallel to the direction of the line connecting the light source 4 and the detector 5.

[0044] The detector 5 is located directly above the detector reflection surface. The detection surface I51 and the detection surface II52 are respectively located at the focal points of the detector reflection surface I23 and the detector reflection surface II24. The detector reflection surface I23 and the detector reflection surface II24 converge the parallel light into two light beams facing the detection surface I51 and the detection surface II52.

[0045] The detector reflection surface I23, the detector reflection surface II24 and the light source reflection surface 22 are independently selected from any one of an off-axis parabola, a sphere or a quadratic surface. The reflection surface determines the convergence point and convergence surface of the parallel light. Its specific structure must meet the requirements of the above-mentioned detection optical path, and is preferably an off-axis parabola.

[0046] The detector reflection surface I 23, the detector reflection surface II 24 and the light source reflection surface 22 need to be high-brightness mirror surfaces and coated with a reflection film, which is not limited to 24K gold, K gold and other materials that are resistant to oxidation and salt spray and have high reflectivity and low absorption rate for light of the absorption wavelength of sulfur hexafluoride. The other surfaces of the optical air chamber 2 are coated with a reflection film, but it is considered that they do not participate in reflection.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A sulfur hexafluoride dual-channel sensor, comprising an optical gas chamber (2), a light source (4) and a detector (5) arranged in the optical gas chamber (2), wherein the light source (4) and the detector (5) are arranged at two ends of the optical gas chamber (2), respectively, and the optical gas chamber (2) is connected to the outside, characterized in that; Also includes: A light source reflecting surface (22), located above the light source (4), and used to redirect light emitted by the light source (4); A detector reflection surface, located above the detector (5), and used to collect light reflected by the light source reflection surface (22) onto the detector (5); The detector reflection surface comprises a detector reflection surface I (23) and a detector reflection surface II (24), and the detector reflection surface I (23) and the detector reflection surface II (24) are arranged side by side and symmetrically; the detector (5) comprises a detection surface I (51) and a detection surface II (52); The light emitted by the light source (4) passes through the light source reflection surface (22) and the detector reflection surface and is received by the detector (5), thereby forming a detection light path.

2. The sulfur hexafluoride dual-channel sensor according to claim 1, characterized in that: The light source (4) is a MEMS infrared light source, and the detector (5) is a dual-channel infrared thermopile or a dual-channel pyroelectric sensor.

3. The sulfur hexafluoride dual-channel sensor according to claim 2, characterized in that: The optical air chamber (2) comprises a shell, an air inlet hole (21) is provided on the shell, and a bottom is provided on a circuit board (3) and is sealed; the shell and the circuit board (3) enclose the optical air chamber (2).

4. The sulfur hexafluoride dual-channel sensor according to claim 3, characterized in that: The air inlet (21) is covered with a waterproof and breathable membrane (1).

5. The sulfur hexafluoride dual-channel sensor according to any one of claims 1 to 4, characterized in that: The light source (4) is arranged at the focal point of the light source reflection surface (22), and reflects the light emitted by the light source (4) into parallel light.

6. The sulfur hexafluoride dual-channel sensor according to claim 5, characterized in that: The light source (4) and the detector (5) are mounted on a circuit board (3). A positioning hole is provided on the circuit board (3). A positioning piece is provided on the housing. The positioning piece can be inserted into the positioning hole to position the light source (4) and the detector (5).

7. The sulfur hexafluoride dual-channel sensor according to claim 6, characterized in that: The detection surface I (51) and the detection surface II (52) are respectively located at the focal points of the detector reflection surface I (23) and the detector reflection surface II (24). The detector reflection surface I (23) and the detector reflection surface II (24) converge the parallel light into two light beams facing the detection surface I (51) and the detection surface II (52).

8. The sulfur hexafluoride dual-channel sensor according to claim 7, characterized in that: The detector reflection surface I (23), the detector reflection surface II (24) and the light source reflection surface (22) are independently selected from any one of an off-axis parabola, a spherical surface or a quadratic surface.

9. The sulfur hexafluoride dual-channel sensor according to claim 8, characterized in that: The detector reflection surface I (23), the detector reflection surface II (24) and the light source reflection surface (22) are all coated with a reflection film.

10. The sulfur hexafluoride dual-channel sensor according to claim 9, characterized in that: The material of the reflective film is 24K gold or K gold.

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