Detector for gas detection

Abstract

The utility model provides a detector for gas detection, which comprises a metal tube seat provided with a mounting surface, and further comprises a metal tube cap fixed on the metal tube seat and provided with a light window; the plane glass lens is mounted on the light window; the photoelectric detector chip is mounted on the mounting surface, is positioned on an incident light path of the plane glass lens and is provided with a light sensing surface; wherein an included angle is formed between the photosensitive surface of the photoelectric detector chip and the plane glass lens. According to the utility model, light noise formed by reflected light generated on the surface and inside of the body of the detector for gas detection during working can be reduced, and the measurement precision of the detector for gas detection is improved, so that the problem of low test precision of a laser gas detection system is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of gas detection by laser sensing, and particularly relates to a detector for gas detection. Background Art

[0002] In the technical field of gas detection in the gas sensing industry, laser detection is used. By measuring the absorption of laser with a specific wavelength by gas, the content of the corresponding gas is measured. Due to its high measurement accuracy, fast response speed, anti-interference and explosion-proof characteristics, it can be used for the detection of flammable and explosive gases.

[0003] To achieve high-precision measurement, it is necessary to ensure that the laser noise in the laser detection system and the optical noise in the optical link are as small as possible. Taking the existing common products as an example, the entire optical link of the laser detection system mainly includes a laser, a detector, a gas chamber, an optical fiber, and passive optical devices for connecting the optical links. Then, the noise generated in the entire optical link, in addition to the noise of the laser light source and the detector receiving body, also includes the optical reflection formed when all the passive optical devices in the optical link are connected to each other, resulting in optical noise. For example, the optical loss and optical reflection caused by the low responsivity of the detector chip inside the detector body form optical noise, the optical noise caused by the surface reflection of the laser beam due to the low transmittance of the detector glass lens, and the reflected light generated between the interface end faces of various passive optical devices in the optical link. These reflected lights will always exist in the entire optical link and gradually generate optical noise formed by optical interference, resulting in an increase in the optical noise in the optical link and a decrease in the signal-to-noise ratio, directly affecting the accuracy and precision of laser gas sensing detection. In severe cases, it may even cause false alarms or downtime of the detection equipment.

[0004] Currently, the semiconductor detectors in the field of gas detection by laser sensing mainly have the following problems:

[0005] The detector for gas detection, as the optical receiving end of the entire laser gas detection system, when the laser beam to be received passes through the glass lens on the detector housing, the laser beam will be reflected on the glass lens on the detector surface, and the reflected light will enter the optical link along the original optical path in the reverse direction, forming optical interference and causing the optical noise in the optical link to increase. The laser beam that passes through the glass lens and enters the detector interior will also be reflected on the photosensitive surface of the semiconductor detector chip, and the reflected light beam will pass through the glass lens along the original optical path, form a reflection again, and continue to enter the detector chip, forming a reflection on the surface of the semiconductor detector chip. When the reflected light between the glass lens and the detector chip oscillates back and forth and forms optical interference, it causes the optical noise inside the gas detection detector to increase, reducing the accuracy of the entire laser gas detection system.

[0006] Therefore, it is necessary to improve the existing gas detection detector to reduce the optical noise formed by the reflected light generated on the surface and inside of the detector body during operation, improve the measurement accuracy of the gas detection detector, and thus solve the problem of low test accuracy of the laser gas detection system. Summary of the Invention

[0007] The purpose of the present invention is to provide a gas detection detector to solve the problem of low accuracy of the existing gas detection detector.

[0008] To solve the above technical problems, the present invention provides a gas detection detector, including a metal base, the metal base having a mounting surface, and further including: a metal cap fixed on the metal base and provided with a light window; a plano-glass lens mounted on the light window; and a photodetector chip mounted on the mounting surface and located on the incident light path of the plano-glass lens and having a photosensitive surface; wherein, the photosensitive surface of the photodetector chip and the plano-glass lens have an included angle.

[0009] Optionally, the photosensitive surface is perpendicular to the axis of the metal base, and the plano-glass lens and the axis of the metal base have an included angle less than 90°.

[0010] Optionally, the photosensitive surface and the axis of the metal base have an included angle less than 90°, and the plano-glass lens and the axis of the metal base have an included angle less than 90°.

[0011] Optionally, the photosensitive surface has a first included angle relative to the axis of the metal base, the plano-glass lens has a second included angle relative to the axis of the metal base, both the first included angle and the second included angle are greater than 0° and less than 90°, the first included angle and the second included angle belong to the same plane, and the opening directions of the first included angle and the second included angle are opposite.

[0012] Optionally, the photosensitive surface has a first included angle relative to the axis of the metal base, the plano-glass lens has a second included angle relative to the axis of the metal base, the first included angle and the second included angle can respectively belong to a first plane and a second plane, the intersection line of the first plane and the second plane is coaxial with the axis of the metal base, and the first plane and the second plane have an included angle greater than 0° and less than 90°.

[0013] Optionally, the metal base and the metal cap are coaxially arranged, and the main optical axis of the optical path is coaxial with the axis of the metal base.

[0014] Optionally, an anti-reflection film is provided on the plano-glass lens.

[0015] Optionally, the photodetector chip is installed on the mounting surface of the metal base, and is fixedly connected by means including but not limited to soldering with metal solder and gluing.

[0016] Optionally, on the optical window of the planar glass lens and the metal tube cap, they are fixedly connected by means including but not limited to soldering with glass solder, soldering with metal solder, and gluing.

[0017] Optionally, the metal base and the metal tube cap are fixedly connected by means including but not limited to laser welding, energy storage welding, soldering with metal solder, and gluing.

[0018] A detector for gas detection provided by the present utility model has the following beneficial effects:

[0019] First, since there is an included angle between the photosensitive surface of the photodetector chip and the planar glass lens, and the photodetector chip is located on the incident light path of the planar glass lens, therefore, the included angle between the planar glass lens and the photosensitive surface of the photodetector chip is less than 90 degrees, and the light passing through the planar glass lens can enter the photodetector chip. Thus, when the laser beam is incident into the gas detection detector along the main optical axis direction of the optical path, at least one of the planar glass lens and the photodetector chip has an included angle less than 90° with the main optical axis of the optical path. Taking the normal line of the planar glass lens surface as the axis of symmetry, the small amount of reflected light generated on the planar glass lens surface forms another included angle of the same angle for reflection, then the reflected light will not be able to enter the optical link along the original optical path of the main optical axis to form optical interference with the incident beam, or the small amount of reflected light generated on the photodetector chip forms another included angle of the same angle for reflection with the normal line of the photosensitive surface of the photodetector chip, then the reflected light will not be able to enter the optical link along the original optical path of the main optical axis to form optical interference with the incident beam, thereby reducing the system optical noise in the entire optical link and improving the accuracy and precision of the laser detection for sensing.

[0020] Second, the opening directions of the first included angle and the second included angle formed by the planar glass lens and the photodetector chip with the main optical axis of the optical path are opposite, avoiding the optical interference caused by the back-and-forth oscillation of the reflected light formed between the planar glass lens and the detector chip, further reducing the optical noise inside the detector, and improving the accuracy and precision of the laser detection for sensing. Description of the Drawings

[0021] Figure 1 is a schematic structural diagram of the gas detection detector in the first embodiment of the present utility model;

[0022] Figure 2 is a schematic structural diagram of the gas detection detector in the second embodiment of the present utility model;

[0023] Figure 3 This is a schematic structural diagram of the detector for gas detection in the third embodiment of the present utility model.

[0024] Explanation of the reference numerals in the drawings:

[0025] 100 - Metal socket; 110 - Mounting surface;

[0026] 200 - Metal cap; 210 - Optical window;

[0027] 300 - Planar glass lens;

[0028] 400 - Photoelectric detector chip;

[0029] 500 - Sealed cavity. Detailed implementation manners

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. Usually, the components of the embodiments of the present utility model described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0031] Therefore, the following detailed description of the embodiments of the present utility model provided in the drawings is not intended to limit the scope of the present utility model to be protected, but merely represents the selected embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the scope of protection of the present utility model.

[0032] It should be noted that: Similar reference numerals and letters indicate similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0033] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the utility model product is usually placed during use. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present utility model. In addition, the terms "first", "second", "third", etc. are only used for descriptive distinction and cannot be construed as indicating or implying relative importance.

[0034] In addition, terms such as "horizontal" and "vertical" do not require the components to be absolutely horizontal or hanging vertically, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0035] In the description of the present utility model, it should also be noted that unless otherwise clearly specified and limited, the terms "set", "installed", "connected", and "connected" should be understood in a broad sense. For example, it 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 directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0036] Reference Figure 1 , Figure 1 FIG. is a schematic structural diagram of a detector for gas detection in Embodiment 1 of the present utility model. The present embodiment provides a detector for gas detection, including a metal tube base 100, the metal tube base having an installation surface 110; a metal tube cap 200 fixed on the metal tube base 100 and provided with a light window 210; a plano-glass lens 300 installed on the light window 210; and a photodetector chip 400 installed on the installation surface 110 and located on the incident light path of the plano-glass lens and having a photosensitive surface.

[0037] In this embodiment, the photosensitive surface of the photodetector chip 400 is perpendicular to the axis of the metal tube base 100, and the plano-glass lens 300 and the axis of the metal tube base 100 have an angle less than 90°.

[0038] Since the plano-glass lens 300 and the axis of the metal tube base have an angle less than 90°, and the photodetector chip 400 is located on the incident light path of the plano-glass lens 300, the plano-glass lens 300 and the photosensitive surface of the photodetector chip 400 have an angle less than 90°, and the light passing through the plano-glass lens 300 can enter the photodetector chip 400. Therefore, when the laser beam is incident on the gas detection detector along the main optical axis direction of the optical path, the angle between the plano-glass lens 300 and the main optical axis of the optical path is less than 90°. Taking the normal line of the surface of the plano-glass lens 300 as the axis of symmetry, the small amount of reflected light generated on the surface of the plano-glass lens 300 forms another angle of the same size for reflection. Then the reflected light will not enter the optical link along the original optical path of the main optical axis to form optical interference with the incident beam, thereby reducing the system optical noise in the entire optical link and improving the accuracy and precision of the laser detection for sensing.

[0039] Preferably, an antireflection film is provided on the planar glass lens 300. By providing an antireflection film on the planar glass lens 300, the light transmittance of the laser beam entering the gas detection detector can be improved. On the one hand, the effective laser beam transmitted into the gas detection detector is increased, allowing more light energy to be received by the detector, and improving the response parameter of the detector; on the other hand, the reflectivity of the surface of the planar glass lens 300 of the gas detection detector is reduced, so that less laser beam is reflected into the optical link of the original optical path, reducing the optical noise in the overall optical link.

[0040] The metal base 100 and the metal cap 200 are coaxially arranged, and the main optical axis of the optical path is coaxial with the axis of the metal base 100.

[0041] The photodetector chip 400 is installed on the installation surface of the metal base 100 and is fixedly connected by means including but not limited to soldering with metal solder and gluing.

[0042] The planar glass lens 300 and the optical window 210 of the metal cap 200 are fixedly connected by means including but not limited to soldering with glass solder, soldering with metal solder, and gluing.

[0043] The metal base 100 and the metal cap 200 are fixedly connected by means including but not limited to laser welding, energy storage welding, soldering with metal solder, and gluing.

[0044] Reference Figure 2 , Figure 2 is a schematic structural diagram of the gas detection detector in the second embodiment of the present invention. In this embodiment, the photosensitive surface of the photodetector chip 400 forms an angle of less than 90° with the axis of the metal base 100, and the planar glass lens 300 forms an angle of less than 90° with the axis of the metal base 100. Preferably, the photosensitive surface has a first angle relative to the axis of the metal base 100, and the planar glass lens 300 has a second angle relative to the axis of the metal base 100. Both the first angle and the second angle are greater than 0° and less than 90°. The first angle and the second angle belong to the same plane, and the opening directions of the first angle and the second angle are opposite. In this way, the photosensitive surface of the photodetector chip 400 and the planar glass lens 300 form an angle state of the sum of the first angle and the second angle. When the laser beam passing through the planar glass lens 300 enters the detector and is reflected on the surface of the semiconductor detector chip 400, the reflected beam does not pass through the planar glass lens 300 along the original optical path again, but is reflected onto the inner wall of the metal cap 200 to form a diffuse reflection, avoiding the optical interference caused by the back-and-forth oscillation of the reflected light formed between the planar glass lens 300 and the detector chip 400, thereby reducing the optical noise in the detector body.

[0045] Reference Figure 3 , Figure 3 is a schematic structural view of the detector for gas detection in the third embodiment of the present utility model. In this embodiment, the photosensitive surface of the detector chip 400 has a first included angle relative to the axis of the metal base 100, and the plano - glass lens 300 has a second included angle relative to the axis of the metal base 100, and the opening directions of the first included angle and the second included angle are opposite; preferably, the first included angle and the second included angle may respectively belong to a first plane and a second plane, the intersection line of the first plane and the second plane is coaxial with the axis of the metal base 100, and the first plane and the second plane have an included angle greater than 0° and less than 90°. In this way, on the one hand, the photosensitive surface of the photoelectric detection chip 400 and the plano - glass lens 300 form an included angle state of the sum of the first included angle and the second included angle in the direction parallel to the main optical axis of the optical path, and on the other hand, an included angle greater than 0° and less than 90° is also formed in the direction perpendicular to the main optical axis of the optical path. This not only avoids the optical interference caused by the back - and - forth oscillation of the reflected light formed between the plano - glass lens 300 and the detector chip 400, but also reduces the reflected light formed on the surface of the detector chip 400 from entering the entire optical link through the plano - glass lens 300. Thus, the optical noise in the detector body and the system optical noise in the entire optical link are reduced simultaneously, and the accuracy and precision of the laser detection for sensing are improved.

[0046] The above description is only a description of the preferred embodiments of the present utility model, and does not limit the scope of the present utility model in any way. Any changes and modifications made by those of ordinary skill in the art of the present utility model according to the above disclosure shall fall within the protection scope of the claims.

Claims

1. A gas detection detector, characterized in that It comprises a metal tube seat, the metal tube seat having a mounting surface, and further comprising: A metal pipe cap is fixed on the metal pipe base and is provided with a light window; a flat glass lens mounted on the light window; and, A photodetector chip, mounted on the mounting surface, located on the incident light path of the plane glass lens, and having a photosensitive surface; Wherein, the photosensitive surface of the photodetector chip and the plane glass lens have an included angle.

2. The gas detection detector according to claim 1, characterized in that: The photosensitive surface is perpendicular to the axis of the metal tube seat, and the plane glass lens and the axis of the metal tube seat have an angle less than 90°.

3. The gas detection detector according to claim 1, characterized in that: The photosensitive surface and the axis of the metal tube seat have an included angle less than 90°, and the plane glass lens and the axis of the metal tube seat have an included angle less than 90°.

4. The gas detection detector according to claim 3, characterized in that: The photosensitive surface has a first angle relative to the axis of the metal tube socket, and the plane glass lens has a second angle relative to the axis of the metal tube socket. The first angle and the second angle are both greater than 0° and less than 90°. The first angle and the second angle belong to the same plane, and the opening directions of the first angle and the second angle are opposite.

5. The gas detection detector according to claim 4, characterized in that: The photosensitive surface has a first angle relative to the axis of the metal tube socket, and the plane glass lens has a second angle relative to the axis of the metal tube socket. The first angle and the second angle may belong to a first plane and a second plane respectively. The intersection of the first plane and the second plane is coaxial with the axis of the metal tube socket, and the first plane and the second plane have an angle greater than 0° and less than 90°.

6. The gas detection detector according to any one of claims 1 to 5, characterized in that: The metal tube seat and the metal tube cap are coaxially arranged, and the main optical axis of the optical path is coaxial with the axis of the metal tube seat.

7. The gas detection detector according to claim 1, characterized in that: An anti-reflection film is arranged on the plane glass lens.

8. The gas detection detector according to claim 1, characterized in that: The photoelectric detector chip is mounted on the mounting surface of the metal tube holder and is fixedly connected by methods including but not limited to metal soldering and gluing.

9. The gas detection detector according to claim 1, characterized in that: The plane glass lens and the light window of the metal tube cap are fixedly connected by means including but not limited to glass solder welding, metal solder welding and gluing.

10. The gas detection detector according to claim 1, characterized in that: The metal tube seat and the metal tube cap are fixedly connected by methods including but not limited to laser welding, energy storage welding, metal solder welding and gluing.

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