CN112378876B - Low-power-consumption miniature infrared gas sensor and implementation method thereof - Google Patents
Low-power-consumption miniature infrared gas sensor and implementation method thereof Download PDFInfo
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
- G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
- G01N21/3504—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
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- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
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- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
- G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
- G01N21/3504—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
- G01N2021/3545—Disposition for compensating effect of interfering gases
Abstract
The invention discloses a low-power consumption miniature infrared gas sensor and an implementation method thereof in the technical field of infrared gas sensing, wherein the sensor comprises an optical gas chamber and a circuit board, an air inlet channel is arranged on an upper cover of the gas chamber in the optical gas chamber, a light source and a detector are arranged on a base of the gas chamber, the light source and the detector are both connected with the circuit board, the cross section of a reflecting wall is elliptic, and the light source and the detector respectively correspond to two focus positions of the ellipse; the method comprises the steps of filling gas, emitting mid-infrared light and reflecting the mid-infrared light, detecting an optical signal and outputting an electric signal by a detector, and carrying out differential calculation by two channels to obtain the concentration of the gas to be measured. According to the invention, by designing the elliptical arc reflector structure, on the premise of ensuring a larger optical path, an optical signal can reach the optical detector through single reflection, so that the problem of increased optical loss caused by light source divergence and multiple reflections is effectively solved, the utilization rate of the optical signal is improved, the power consumption of the light source is reduced, and the low-power-consumption infrared gas sensor is realized.
Description
Technical Field
The invention relates to the technical field of intermediate infrared gas sensing, in particular to a low-power-consumption miniature infrared gas sensor and an implementation method thereof.
Background
In recent years, with the rapid development of the economy of China, the specific gravity of industrial gas in the economy of China is higher and higher, and the industrial gas is widely applied to the fields of petroleum, chemical engineering, agriculture, medical treatment, food, clean energy, urban residents and the like. Industrial gas often has characteristics such as flammability, toxicity nature, suffocation nature, explosive, and when its concentration exceedes the safety permission scope, easily leads to the incident to take place, therefore, effective monitoring to industrial gas concentration is the important means of guarantee gas safety. Industrial gas sensors have a great market demand as an important guarantee of gas safety, and have been gradually developed in recent years toward low power consumption, miniaturization, and portability.
The infrared optical gas sensor has the advantages of fast response, high measurement precision, strong anti-interference capability, long service life and the like, does not have the phenomena of harmful gas poisoning, aging and the like, and is widely accepted by the market. The working principle is that gas molecules have absorption effect on infrared light signals with specific wavelength due to inherent vibration and rotation frequency, and the light absorption intensity is in positive correlation with the concentration of the gas molecules. Therefore, by detecting the power change of the optical signal with the specific wavelength interacted with the gas molecules, the accurate detection of the specific gas concentration can be realized.
Currently, a halogen lamp infrared light source is used in a common infrared gas sensor in the prior art. In order to ensure that the photodetector in the sensor can obtain a sufficiently strong optical signal, the most direct method is to enhance the luminous efficiency of the light source. However, the larger the luminous intensity of the infrared light source is, the larger the power consumption is, which has become the main source of the current power consumption of the infrared gas sensor, and is not favorable for satisfying the demand of the infrared gas sensor developing towards the direction of small volume, low power consumption and low cost. In addition, some existing infrared gas sensors need to implement multiple reflections of light in a limited volume for small volume of products, which undoubtedly increases the loss of light energy.
The above-mentioned drawbacks are worth solving.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention provides a low-power-consumption miniature infrared gas sensor and an implementation method thereof.
The technical scheme of the invention is as follows:
on one hand, the low-power consumption miniature infrared gas sensor is characterized by comprising an optical gas chamber and a circuit board, wherein the optical gas chamber comprises a gas chamber upper cover, a reflecting wall and a gas chamber base, the reflecting wall is positioned between the gas chamber upper cover and the gas chamber base, the gas chamber upper cover is provided with an air inlet channel, the gas chamber base is provided with a light source and a detector, and the light source and the detector are both connected with the circuit board,
the cross section of the reflecting wall is in an ellipse shape, and the light source and the detector respectively correspond to two focus positions of the ellipse.
The invention according to the above scheme is characterized in that the gas chamber upper cover is provided with a downward inclined plane reflector, and the inclined plane reflector is positioned right above the detector.
The invention according to the above scheme is characterized in that an upper protrusion is arranged at the upper end of the reflecting wall, the upper protrusion is inserted into the air chamber upper cover, a lower protrusion is arranged at the lower end of the reflecting wall, and the lower protrusion is inserted into the air chamber base.
Furthermore, the upper bulge is inserted into the air inlet channel of the air chamber upper cover, a fixing groove is formed in the air chamber base, and the lower bulge is inserted into the fixing groove.
The invention according to the above scheme is characterized in that a light source reflector is arranged in the optical gas chamber, and the light source reflector is located between the light source and the detector.
The invention according to the above aspect is characterized in that an inner wall of the optical air chamber is coated with a light reflecting material.
On the other hand, the realization method of the low-power consumption miniature infrared gas sensor is characterized in that,
filling the gas to be detected in the optical air chamber;
the light source positioned at one focus of the elliptic optical air chamber emits mid-infrared light, the mid-infrared light irradiates the reflecting wall and then is reflected, and light reflected by the reflecting wall is emitted into the detector positioned at the other focus of the elliptic optical air chamber;
a measurement channel in the detector detects an infrared light signal with the same absorption spectrum as that of the gas to be detected, a reference channel detects a mid-infrared light signal which is not absorbed by the gas to be detected, and the measurement channel and the reference channel convert the detected infrared light signal into an electric signal to be output;
and performing differential calculation on the electrical signal output of the reference channel and the electrical signal output of the measurement channel, and calculating the concentration of the gas to be measured according to a differential value.
According to the scheme, the invention has the beneficial effects that through the design of the elliptical arc-shaped reflector structure, on the premise of ensuring a larger optical path, a medium infrared light signal can reach the optical detector through single reflection, the problem of increased optical loss caused by light source divergence and multiple reflections is effectively solved, and the utilization rate of the optical signal is improved, so that the power consumption of the light source is reduced, the low-power-consumption infrared gas sensor is realized, meanwhile, the miniaturized design of the gas sensor can be realized, the labeling size of the electrochemical sensor commonly used in the field is reached, and the compatibility with the existing gas sensor instrument is realized.
Drawings
FIG. 1 is a schematic structural view of the present invention;
FIG. 2 is a schematic view of another embodiment of the present invention;
FIG. 3 is an exploded view of the present invention;
FIG. 4 is an exploded view of the present invention from another perspective;
FIG. 5 is a side cross-sectional view of the present invention;
FIG. 6 is a schematic diagram of the light path within an ellipse;
FIG. 7 is a light path diagram of the present invention;
fig. 8 is a graph showing changes in measurement signals and methane gas concentration.
In the figure, 10-air chamber upper cover; 11-a beveled mirror; 12-mounting holes on the light source reflector; 13-an intake passage;
20-a reflective wall; 21-upper bulge; 22-lower projection;
30-air chamber base; 31-a light source; 32-a detector; 321-a measurement channel; 322-reference channel; 33-a fixed groove; 34-a light source reflector;
40-a circuit board; 41-signal processing circuit components.
Detailed Description
The invention is further described with reference to the following figures and embodiments:
as shown in fig. 1 to 7, a low power consumption micro infrared gas sensor includes an optical gas chamber and a circuit board 40, the optical gas chamber includes a gas chamber upper cover 10, a reflective wall 20 and a gas chamber base 30, the reflective wall 20 is located between the gas chamber upper cover 10 and the gas chamber base 30. The inner wall of the optical gas cell is coated with a light reflecting material. Preferably, gold is selected as the light reflecting material, so that the inner wall of the optical air chamber is coated with the gold layer.
The upper cover 10 of the air chamber is provided with an air inlet channel 13, so that the concentration of the gas inside the air chamber is consistent with that of the gas in the external environment. The gas chamber base 30 is provided with a light source 31 and a detector 32, and the light source 31 and the detector 32 are both located on the upper surface of the gas chamber base 30, wherein the light source 31 is used for emitting mid-infrared light signals, and the detector 32 is used for detecting light signals after passing through the gas to be detected. The light source 31 and the detector 32 are both connected with the circuit board 40, the circuit board 40 is provided with a signal processing circuit component 41 for realizing the processing of the emission and absorption light signals of the light source 31, the mid-infrared signal emitted by the light source 31 is absorbed by the gas to be detected in the optical gas chamber and then received by the detector 32, and the signal of the detector 32 is processed by the signal processing circuit component 41 on the circuit board 40 and a corresponding line to output the concentration value of the gas to be detected, so as to realize the detection of the gas concentration.
The inner wall of the reflecting wall 20 is a reflecting surface, the cross section of the reflecting wall 20 is elliptical, the light source 31 and the detector 32 correspond to two elliptical focus positions respectively, the light source 31 and the detector 32 are respectively arranged at two elliptical focuses, light emitted by the light source 31 is reflected by the reflecting wall 20 and then directly enters the detector 32, on the premise that a large optical path is ensured, the light signal can reach the light detector 32 through single reflection, the problem that light loss is increased due to divergence and multiple reflections of the light source 31 is effectively solved, the space occupied by the sensor optical path can be saved, the miniaturized design of the sensor is realized, meanwhile, the utilization rate of the light signal can be improved, low power consumption and low cost design are realized.
The upper end of the reflecting wall 20 is provided with an upper protrusion 21, the upper protrusion 21 is inserted into the upper cover 10 of the air chamber, the lower end of the reflecting wall 20 is provided with a lower protrusion 22, and the lower protrusion 22 is inserted into the base 30 of the air chamber.
The air inlet channel 13 can be a through hole or a grid hole, and when the air inlet channel 13 is designed to be a grid hole, the upper protrusion 21 is inserted into the air inlet channel 13 of the air chamber upper cover 10. A lateral wall of air inlet channel 13 in this embodiment is the arc design, and the radian is unanimous with the radian of last arch 21, and its arc length is unanimous with the arc length of last arch 21 for in last arch 21 can insert air inlet channel 13, avoid seting up special fixed orifices on air chamber upper cover 10. The air chamber base 30 is provided with fixing grooves 33, the fixing grooves 33 are formed in the same shape and size as the lower protrusions 22, and the lower protrusions 22 are inserted into the fixing grooves 33.
Preferably, two symmetrical air inlet channels 13 are arranged on the air chamber upper cover 10, so that air can uniformly enter the optical air chamber, the distribution of the air in the optical air chamber is ensured to be more uniform, and the detection accuracy is higher.
The gas chamber upper cover 10 is provided with a downward inclined reflector 11, and the inclined reflector 11 is located right above the detector 32 and faces the light source 31. The surface of the inclined reflector 11 is coated with a reflective material, so that the light emitted from the light source 31 can be directly reflected to the detector 32 after being irradiated on the inclined reflector 11, and the effective transmission of the light is realized. Preferably, the included angle between the inclined reflector 11 and the upper cover 10 of the air chamber is 45 degrees, and the height of the center of the inclined reflector 11 is consistent with that of the light source 31, so that the precision control of the light transmission angle can be ensured, and the detection signal is more accurate; meanwhile, the arrangement of the inclined reflector 11 prevents the light emitted by the light source 31 from being continuously reflected and lost in the elliptical range, so that the light emitted by the light source 31 can be directly detected by the detector 32 after being reflected, and the inclined reflector plays an important role in the utilization rate of the light energy of the light source 31.
In the present invention, a light source reflector 34 (concave mirror) is disposed in the optical gas cell, the light source reflector 34 is located between the light source 31 and the detector 32, and the radius of curvature of the light source reflector 34 is equal to the distance from the inner wall to the center point of the light source 31. Preferably, the light source reflector 34 is arc-shaped, and the light source 31 is located at the center of the arc-shaped light source reflector 34, so as to prevent the optical signal emitted by the light source 31 from directly entering the detector 32. At this time, the optical signal emitted by the light source 31 is refocused to the position of the light source 31 and then reflected to the detector 32 through the reflecting wall 20, so that the optical signal is prevented from directly entering the detector 32 without being reflected, the effective optical path is increased through two reflections, and the detection precision of the detector 32 is improved.
The symmetry axis of the light source reflector 34 in this embodiment coincides with the ellipse major axis of the optical air chamber, so that the light source reflector 34 has the same reflection effect on the light on both sides of the ellipse major axis, and the detection accuracy of the sensor is further increased.
The present invention has the following advantages by the application of the light source reflector 34:
(1) because the optical path of the part of the optical signal of the light source 31 directly entering the detector 32 is short, the gas absorbs the optical signal lower, and the part of the optical energy occupies the dominant position of the energy received by the detector, the absorption effect of the gas on the light is reduced, and the accuracy of the sensor is influenced, the invention avoids the direct incidence of the light source 31 to the detector 32 through the light source reflector 34, and reduces the influence of the part of the light on the whole optical energy.
(2) If the light from the light source 31 directly enters the detector, the gas absorption of the short-range light is weak, and occupies the dominant optical power of the detector, so that the detector 32 has strong background light, the proportion of the gas absorption optical power to the optical power of the whole detector is reduced, and even the optical power change caused by gas absorption is submerged, thereby causing the sensor accuracy to be insufficient. The invention can enable as much light as possible to reach the detector after being transmitted by a long optical path, ensures the high-efficiency absorption effect of light energy and gas and improves the precision of the sensor.
Preferably, the upper cover 10 of the air chamber is provided with an upper mounting hole 12 of the light source reflector, the base 30 of the air chamber is provided with a lower mounting hole of the light source reflector, the upper end and the lower end of the light source reflector 34 are respectively inserted into the upper mounting hole 12 of the light source reflector and the lower mounting hole of the light source reflector, and the light source reflector 34 is fixed through the upper mounting hole 12 of the light source reflector and the lower mounting hole of the light source reflector, so that the stability of the light source reflector is ensured.
The detector 32 of the present invention includes a measurement channel 321 and a reference channel 322, wherein filters with different wavelengths are installed on the measurement channel 321 and the reference channel 322. The wavelength of the filter on the measurement channel 321 is the same as the absorption wavelength of the gas to be measured, and the wavelength of the filter on the reference channel 322 is different from the absorption wavelength of the gas to be measured. Measurement channel 321 may be enabled to detect optical signals having the same wavelength as the gas to be measured, and reference channel 322 may be enabled to measure optical signals having a different wavelength from the gas to be measured (measure optical signals that are not absorbed by the gas to be measured) such that the wavelengths absorbed by the two are staggered.
Preferably, a connecting line of the measurement channel 321 and the reference channel 322 is perpendicular to a long axis of the ellipse, so that the measurement channel 321 and the reference channel 322 can fully receive the optical signal, and the intensity of the optical signal received by the measurement channel 321 and the intensity of the optical signal received by the reference channel 322 are the same, thereby ensuring the detection accuracy.
In the present embodiment, since the light source 31 is not a strict point light source, and has a light emitting surface with a certain size, the light source 31 is placed at one focal point of the ellipse, and then a light spot with a certain area is formed at the position of the other focal point. Thus at the other focal point, measurement channel 321 and reference channel 322 are both located within the spot, such that both measurement channel 321 and reference channel 322 can receive optical signals. In addition, the light diffusely reflected by the inclined reflector 11 can be uniformly incident into the measurement channel 321 and the reference channel 322.
As shown in fig. 6 and 7, the reflecting wall 20 of the optical air chamber is designed to be elliptical, and the light source 31 and the detector 32 are respectively placed at the first focal point (P1 of fig. 6) and the second focal point (P2 of fig. 6) of the elliptical reflecting wall 20, so that the light signal emitted by the light source 31 is reflected by the elliptical reflecting wall 20 and finally converged at the detector 32, and the light paths of the light emitted by the light source 31 in all directions converged at the detector 32 are equal, and on the premise of ensuring a large light path, the light signal can reach the light detector 32 through single reflection, thereby effectively solving the problem of increased light loss caused by divergence and multiple reflections of the light source 31.
The implementation method of the low-power consumption miniature infrared gas sensor comprises the following implementation steps:
(1) filling the gas to be detected in the optical air chamber;
(2) the light source 31 positioned at one focus of the elliptic optical air chamber emits mid-infrared light, the mid-infrared light irradiates the reflecting wall 20 and then is reflected, and light reflected by the reflecting wall 20 is irradiated into the detector 32 positioned at the other focus of the elliptic optical air chamber;
(3) a measurement channel 321 in the detector 32 detects an infrared light signal with the same absorption spectrum as that of the gas to be detected, a reference channel 322 detects a mid-infrared light signal which is not absorbed by the gas to be detected, and the measurement channel 321 and the reference channel 322 convert the detected infrared light signal into an electric signal to be output;
(4) the electrical signal output of the reference channel 322 and the electrical signal output of the measurement channel 321 are subjected to difference calculation, and the concentration of the gas to be measured is obtained through difference value calculation. Because the interference of the fluctuation of the light source 31 and the scattering of the air chamber on the measurement result can be counteracted by the differential operation (ratio) of the measurement channel 321 and the reference channel 322, the accurate calculation result can be obtained by performing the differential operation on the electric signals of the reference channel 322 and the measurement channel 321 and calculating the differential value.
In the process of signal processing in step (4), setting the electrical signal output of the reference channel 322 as I1, setting the electrical signal output of the measurement channel 321 as I2, and performing differential calculation on the output I1 of the reference channel 322 and the output T2 of the measurement channel 321 to obtain I = I2/I1; and then according to the positive correlation between the measured differential signal I and the concentration (C) of the gas to be measured: i = f (C), and gas concentration calibration is carried out according to the relation; and finally, outputting the concentration of the gas to be detected according to the obtained differential signal I.
In the implementation process, the light source 31 and the detector 32 are respectively placed at two focuses of the ellipse, the light emitted from the light source 31 in different angle directions is reflected by the elliptical arc-shaped reflecting wall 20 and converged to the detector 32, and both have the same optical path, and meanwhile, because the reflection times are few, the reflection loss is low, and the light condensation efficiency is high, the utilization rate of optical signals can be effectively improved, so that the output optical power of the light source 31 is reduced, and the design target of the low-power infrared gas sensor is realized.
Taking the methane gas test as an example, as shown in fig. 8, the optical gas chamber is filled with methane gas, the signal of the measurement channel 321 decreases with increasing methane gas concentration due to gas absorption, and the signal of the reference channel 322 remains unchanged. Besides different responses to gas, the measurement signal and the reference signal have the same response to other external signals, such as reduction of reflectivity of the inner wall of the gas chamber, reduction of optical power caused by aging of the light source 31 and the like, so that the gas concentration is obtained through differential signal calculation, interference of other signals except gas can be effectively eliminated, and the sensor can accurately reflect the concentration information of the gas.
The infrared gas sensor of the invention has the following advantages:
(1) according to the invention, through the elliptical design of the reflecting wall 20, the light source 31 and the detector 32 are respectively arranged at the first focus and the second focus of the elliptical arc reflecting wall 20, so that light signals emitted by the intermediate infrared light source are finally converged at the detector 32 after being reflected by the elliptical arc reflecting wall 20, and the light paths of the light emitted by the light source 31 in all directions converged to the detector 32 are equal, thereby being beneficial to ensuring the full action of light and gas, improving the utilization efficiency of light energy, simultaneously being beneficial to keeping the consistency and stability of parameter performance among sensors and being beneficial to batch production;
(2) a light source reflector 34 is arranged between the light source 31 and the detector 32, so that an optical signal emitted by the light source 31 can be prevented from directly entering the detector 32 without reflection, an effective optical path is increased by two reflections, and the detection precision of the detector 32 is improved;
(3) the two air inlet channels 13 on the air chamber upper cover 10 can ensure that the concentration of the gas in the optical air chamber is consistent with that of the gas in the external environment, and the distribution of the gas in the optical air chamber is more uniform;
(4) the gold-plated reflecting film on the inner wall of the optical air chamber can reduce scattering loss and improve the reflectivity of light, and the design of the inclined reflector 11 of the upper cover 10 of the air chamber can effectively ensure that optical signals are fully emitted into the detector 32, so that the detection efficiency of the detector 32 on the optical signals is improved, and the power consumption of the light source 31 is reduced.
The invention has the advantages of simple structure, high optical path consistency, small light scattering loss and high light detection efficiency, thereby being beneficial to reducing the power consumption of the sensor and meeting the requirements of the infrared gas sensor on development towards small volume, low power consumption and low cost.
It will be understood that modifications and variations can be made by persons skilled in the art in light of the above teachings and all such modifications and variations are intended to be included within the scope of the invention as defined in the appended claims.
The invention is described above with reference to the accompanying drawings, which are illustrative, and it is obvious that the implementation of the invention is not limited in the above manner, and it is within the scope of the invention to adopt various modifications of the inventive method concept and technical solution, or to apply the inventive concept and technical solution to other fields without modification.
Claims (5)
1. A low-power consumption miniature infrared gas sensor is characterized by comprising an optical gas chamber and a circuit board, wherein the optical gas chamber comprises a gas chamber upper cover, a reflecting wall and a gas chamber base, the reflecting wall is positioned between the gas chamber upper cover and the gas chamber base, the gas chamber upper cover is provided with an air inlet channel, the gas chamber base is provided with a light source and a detector, the light source and the detector are both connected with the circuit board,
the cross section of the reflecting wall is in an ellipse shape, and the light source and the detector respectively correspond to two focal positions of the ellipse;
the upper end of the reflecting wall is provided with an upper bulge, the upper bulge is inserted into the air chamber upper cover, the lower end of the reflecting wall is provided with a lower bulge, and the lower bulge is inserted into the air chamber base;
the optical air chamber is internally provided with a light source reflector, the light source reflector is positioned between the light source and the detector, the curvature radius of the light source reflector is equal to the distance from the inner wall of the light source reflector to the central point of the light source, the light source reflector is arc-shaped, and the light source is positioned at the arc-shaped circle center of the light source reflector.
2. The low power consumption micro infrared gas sensor as claimed in claim 1, wherein the gas chamber upper cover is provided with a downward inclined reflector, and the inclined reflector is located right above the detector.
3. The low-power consumption micro infrared gas sensor as claimed in claim 1, wherein the upper protrusion is inserted into the gas inlet channel of the upper cover of the gas chamber, the base of the gas chamber is provided with a fixing groove, and the lower protrusion is inserted into the fixing groove.
4. The low power micro infrared gas sensor of claim 1, wherein the inner wall of the optical gas cell is coated with a light reflecting material.
5. A method for implementing a low power consumption micro infrared gas sensor as claimed in any one of claims 1 to 4,
filling the gas to be detected in the optical air chamber;
the light source positioned at one focus of the elliptic optical air chamber emits mid-infrared light, the mid-infrared light irradiates the reflecting wall and then is reflected, and light reflected by the reflecting wall is emitted into the detector positioned at the other focus of the elliptic optical air chamber;
a measurement channel in the detector detects an optical signal with the same absorption spectrum as that of the gas to be detected, a reference channel detects a mid-infrared optical signal which is not absorbed by the gas to be detected, and the measurement channel and the reference channel convert the detected infrared optical signal into an electric signal to be output;
and performing differential calculation on the electrical signal output of the reference channel and the electrical signal output of the measurement channel, and calculating the concentration of the gas to be measured according to a differential value.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN202011211149.6A CN112378876B (en) | 2020-11-03 | 2020-11-03 | Low-power-consumption miniature infrared gas sensor and implementation method thereof |
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| CN202011211149.6A CN112378876B (en) | 2020-11-03 | 2020-11-03 | Low-power-consumption miniature infrared gas sensor and implementation method thereof |
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| CN115165788B (en) * | 2022-07-20 | 2023-06-16 | 深圳市诺安智能股份有限公司 | High-resolution miniature infrared gas sensor and implementation method thereof |
| CN115184293B (en) * | 2022-07-22 | 2023-06-20 | 深圳市诺安智能股份有限公司 | Miniature infrared gas sensor with consistent optical path length and implementation method |
| CN116183541B (en) * | 2023-04-24 | 2023-06-23 | 南方电网科学研究院有限责任公司 | Gas measurement method and device based on FTIR technology |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010277707A (en) * | 2009-05-26 | 2010-12-09 | Harison Toshiba Lighting Corp | Lamp device for illumination |
| EP2573546A1 (en) * | 2010-05-21 | 2013-03-27 | National Institute of Advanced Industrial Science And Technology | Gas sensor |
| CN107219183A (en) * | 2017-06-20 | 2017-09-29 | 安徽徽智科学仪器有限公司 | Open light path type atmospheric trace gas infrared detecting device |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101694457B (en) * | 2009-10-19 | 2011-01-05 | 浙江大学 | Gas concentration measuring instrument |
| CN108318439B (en) * | 2018-03-16 | 2020-12-29 | 中电科技集团重庆声光电有限公司 | Full-integrated infrared gas sensor based on oval air chamber structure |
| CN110057773A (en) * | 2019-05-05 | 2019-07-26 | 南京信息工程大学 | A kind of infrared gas sensor system and the temperature-compensation method based on AACA-Elman algorithm |
| CN110006837A (en) * | 2019-05-05 | 2019-07-12 | 南京信息工程大学 | A kind of NDIR gas sensor system and humiture compensation method |
| CN110361355B (en) * | 2019-08-15 | 2024-01-05 | 深圳市诺安智能股份有限公司 | Spiral gas concentration detection device, manufacturing method thereof and alarm device |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010277707A (en) * | 2009-05-26 | 2010-12-09 | Harison Toshiba Lighting Corp | Lamp device for illumination |
| EP2573546A1 (en) * | 2010-05-21 | 2013-03-27 | National Institute of Advanced Industrial Science And Technology | Gas sensor |
| CN107219183A (en) * | 2017-06-20 | 2017-09-29 | 安徽徽智科学仪器有限公司 | Open light path type atmospheric trace gas infrared detecting device |
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