Patent ID: 12203843

In the figures,1denotes metal screen,2denotes vent hole,3denotes upper cover of sensor probe,4denotes multi-point total reflection type long-optical-path module,5denotes lower cover of sensor probe,6denotes signal processing circuit,7denotes base,8denotes parallel laser source,9denotes temperature and pressure sensor,10denotes photoelectric detector, and11denotes right-angle reflecting prism or reflecting mirror pair.

DETAILED DESCRIPTION

It should be noted that the following detailed descriptions are all exemplary and are intended to provide a further understanding of the present disclosure. Unless otherwise indicated, all technical terms and scientific terms used in this application have the same meaning as commonly understood by a person of ordinary skill in the art to which the present disclosure belongs.

It should be noted that terms used herein are only for describing specific implementations and are not intended to limit exemplary implementations according to the present disclosure. As used herein, the singular form is intended to include the plural form, unless the context clearly indicates otherwise. In addition, it should further be understood that terms “comprise” and/or “include” used in this specification indicate that there are features, steps, operations, devices, components, and/or combinations thereof.

The embodiments in the present disclosure and features in the embodiments may be mutually combined in case that no conflict occurs.

Embodiment 1

In one or more implementations, a two-dimensional multi-point-reflection long-optical-path gas sensor probe is disclosed. Referring toFIG.1, the two-dimensional multi-point-reflection long-optical-path gas sensor probe includes: a protecting housing, a multi-point total reflection type long-optical-path module4arranged in the protecting housing, a parallel laser source8, a photoelectric detector10and a gas absorption chamber.

Specifically, referring toFIG.2(a)-(b), the protecting housing is composed of an upper cover3of the sensor probe with an air intake filter device and a lower cover5of the sensor probe. A top end of the upper cover3of the sensor probe is provided with a replaceable metal screen1for preventing dust, impurities and the like from entering the absorption chamber and contaminating optical components in an optical path. A plurality of vent holes2are formed under the metal screen1. The measured gas diffuses from the vent holes2into the gas absorption chamber through the metal screen1.

In this embodiment, referring toFIG.3, the multi-point total reflection type long-optical-path module4includes two identical right-angle reflecting prisms or reflecting mirror pairs11. It should be noted that the right-angle reflecting prism or reflecting mirror pair11may be a right-angle triangular prism, or may be in a form of a triangular reflecting mirror pair consisting of two plane reflecting mirrors perpendicular to each other. Alternatively, those skilled in the art can select other forms of right-angle reflecting prisms or reflecting mirror pairs according to needs.

In this embodiment, the form of the right-angle triangular prism is adopted. Two right-angle triangular prisms are spaced at a set distance and are embedded in a rigid base7, and inclined surfaces of the two right-angle prisms are placed to be opposite to each other and parallel to each other.

Those skilled in the art can understand that a distance between the inclined surfaces of the two right-angle triangular prisms can be set according to an optical path required by a gas sensor.

Center lines of the two right-angle triangular prisms have a relative deviation value. For a right-angle triangular prism of a certain size, by adjusting the deviation value, a parallel light beam parallel to the center line of the prism can be totally reflected for different numbers of times sequentially in the two prisms, thereby generating different numbers of reflected light beams.

A gas absorption chamber with a cuboid structure in which the measured gas can be introduced is placed in a space between the inclined surfaces of the two right-angle triangular prisms.

Of course, the structure of the gas absorption chamber is not limited to the cuboid structure. Those skilled in the art can adjust the structure according to the needs of different application scenes, such as a cylindrical box-like structure and a rectangular box-like structure.

As an optional embodiment, an entrance window and an exit window of the absorption chamber are flat glass specially treated by anti-water condensation. After the treatment with an anti-water condensation film, measurement errors caused by the influence of humidity on the optical path can be effectively reduced.

A group of two-dimensional parallel light beams generated by double prism multi-point reflection enter and exit the absorption chamber through the flat glass windows in two sides of the absorption chamber, so as to form sensing light beams.

One side surface of the gas absorption chamber with the cuboid structure is provided with a plurality of vent holes2, and the measured gas diffuses through the metal screen1and the vent holes2into the gas absorption chamber. A temperature and pressure sensor9for measuring temperature and pressure in the gas absorption chamber is mounted in one of the vent holes2of the absorption chamber. The temperature and pressure information will be used for compensating for parameter changes due to ambient temperature fluctuations and pressure changes, so as to further improve the ambient temperature and pressure adaptability of the gas measurement.

As an optional embodiment, an inner wall cavity of the gas absorption chamber with the cuboid structure is coated with a black light-absorbing coating, so as to reduce the influence of stray light and play a role of corrosion prevention.

Referring toFIG.4andFIG.5, in an optical path module, a parallel laser source8parallel to the center line of the prism is mounted beside a first right-angle triangular prism, that is, at an acute angle end of the right-angle triangular prism, and a photoelectric detector10is mounted at the other acute angle end of a second right-angle triangular prism. A focusing lens for focusing the parallel light on a detection sensitive surface is arranged in front of the photoelectric detector10.

A parallel light beam emitted by the laser source8is parallel to the center line of the prism, and can be received and reflected by the second right-angle triangular prism. When a parallel laser beam is vertically irradiated on the inclined surface of the second right-angle triangular prism, the light beam is totally reflected by two right-angle surfaces of the second right-angle triangular prism, so as to form a first parallel reflected light beam parallel to an incident light beam. The light beam is vertically irradiated on the inclined surface of the first right-angle triangular prism after passing through the gas absorption chamber. Then, the light beam is totally reflected by two right-angle surfaces of the first right-angle triangular prism and passes through the absorption chamber, so as to form a second parallel reflected light beam. In this way, the parallel laser beam is reflected for multiple times sequentially by the two prisms, so as to form a group of two-dimensional parallel light beams After the light beam is reflected for the last time by the first right-angle triangular prism, the light beam reaches the photoelectric detector10through the absorption chamber, thereby forming a complete measurement optical path. These two-dimensional parallel light beams pass through the flat glass windows in two sides of the gas absorption chamber and enter the gas absorption chamber to form sensing light beams.

As an optional embodiment, the wavelength tunable laser source with a parallel light beam8has a built-in light intensity detector10. Changes of the light intensity of the wavelength tunable laser source8can be measured by the built-in light intensity detector. The laser source may be a vertical cavity surface emitting laser (VCSEL) with low power consumption, or may be a distributed negative feedback laser (DFB). An output signal of the light intensity detector is directly proportional to the light intensity of an output light of the laser, and therefore, this signal can be used as a feedback signal for monitoring changes in light intensity of the laser and compensating for these changes.

The parallel light beam emitted by the laser source is reflected for multiple times by two right-angle triangular prisms, and enters or exits a gas chamber successively through two light-transmitting windows of the gas absorption chamber. After multi-reflections, the reflected light beam reflected for the last time by the prism passes through the absorption chamber, and is received by the photoelectric detector10.

As an optional embodiment, the photoelectric gas sensor probe is further provided with an electronic processing circuit for modulating the wavelength of the laser source as well as amplifying and adjusting a measurement signal of the photoelectric detector10.

Embodiment 2

In one or more implementations, a two-dimensional multi-point-reflection long-optical-path gas sensor probe is disclosed. The differences between the structure of the sensor probe in this embodiment and that in Embodiment 1 lie in that: referring toFIG.6(a)-(b), in this embodiment, two reflecting mirror pairs consisting of plane reflecting mirrors perpendicular to each other are adopted to replace reflecting surfaces of the two right-angle triangular prisms. A reflecting surface of a first reflecting mirror pair is provided with a laser source8, and the other reflecting surface of the other reflecting mirror pair is provided with a photoelectric detector10. A parallel light beam emitted by the laser source8is absorbed by the photoelectric detector10after being reflected for multiple times by the first reflecting mirror pair and the second reflecting mirror pair.

The remaining structure is the same as that of the two-dimensional multi-point-reflection long-optical-path gas sensor probe in Embodiment 1, and will not be repeated here.

Embodiment 3

In one or more implementations, a two-dimensional multi-point-reflection long-optical-path gas sensor probe is disclosed. Referring toFIG.7(a)-(b), the differences between the structure of the sensor probe in this embodiment and that in Embodiment 1 lie in that: in this embodiment, in two right-angle triangular prisms, an acute angle end of a first right-angle triangular prism is provided with a parallel laser source8, and the other acute angle end is provided with a photoelectric detector10. An acute angle end of a second right-angle triangular prism is provided with a third right-angle triangular prism. A parallel light beam emitted by the laser source8is absorbed by the photoelectric detector10after being reflected for multiple times by the first right-angle triangular prism, the second right-angle triangular prism and the third right-angle triangular prism.

In this structure, the laser source8and the photoelectric detector10can be placed at the same side of the gas absorption chamber. Therefore, corresponding light source driving circuit and signal processing circuit6can be placed at one end of the sensor probe, so as to make the overall design more compact.

It can be understood that the right-angle triangular prism in this embodiment can also be replaced by a reflecting mirror pair consisting of two plane reflecting mirrors perpendicular to each other, or other right-angle reflecting mirror pairs that can be conceived by those skilled in the art.

The remaining structure is the same as that of the two-dimensional multi-point-reflection long-optical-path gas sensor probe in Embodiment 1, and will not be repeated here.

Embodiment 4

In one or more implementations, a two-dimensional multi-point-reflection long-optical-path gas sensor probe is disclosed. Referring toFIG.8(a)-(b), the differences between the structure of the sensor probe in this embodiment and that in Embodiment 1 lie in that: in this embodiment, in two right-angle triangular prisms, an acute angle end of a first right-angle triangular prism is respectively provided with a laser source8and a photoelectric detector10. A small reflecting prism is mounted at an acute angle end of a second right-angle triangular prism, and a reflecting surface of the reflecting prism is arranged along a direction perpendicular to the light beam.

After a parallel light beam emitted by the laser source8is reflected for multiple times by the first right-angle triangular prism and the second right-angle triangular prism, a first layer of parallel light beam group is formed. And then the reflected light beam from the first layer is reflected by two reflective surfaces of a vertical right-angle prism to enter a second layer of the light beam, and after the light beam is reflected for multiple times again by the second right-angle triangular prism and the first right-angle triangular prism, the second layer of parallel light beam group is formed, and the light beam in the second layer after multi-reflections is then received by the photoelectric detector10.

This optical path design doubles the detection optical path of the sensor. Moreover, the light source and the photoelectric detector10are arranged at the same side of the gas absorption chamber and are adjacent, thereby simplifying the design of a circuit board.

It can be understood that the right-angle triangular prism in this embodiment can also be replaced by a reflecting mirror pair consisting of plane reflecting mirrors perpendicular to each other, or other right-angle reflecting mirror pairs that can be conceived by those skilled in the art.

The remaining structure is the same as that of the two-dimensional multi-point-reflection long-optical-path gas sensor probe in Embodiment 1, and will not be repeated here.

Embodiment 5

In one or more implementations, a gas sensor is disclosed, which uses any two-dimensional multi-point-reflection long-optical-path gas sensor probe disclosed in Embodiment 1 or Embodiment 2 or Embodiment 3 or Embodiment 4.

The specific implementations of the present disclosure are described above with reference to the accompanying drawings, but are not intended to limit the protection scope of the present disclosure. A person skilled in the art should understand that various modifications or deformations may be made without creative efforts based on the technical solutions of the present disclosure, and such modifications or deformations shall fall within the protection scope of the present disclosure.