CN114577747A - Gas detector by ultraviolet absorption method - Google Patents
Gas detector by ultraviolet absorption method Download PDFInfo
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- CN114577747A CN114577747A CN202210356509.4A CN202210356509A CN114577747A CN 114577747 A CN114577747 A CN 114577747A CN 202210356509 A CN202210356509 A CN 202210356509A CN 114577747 A CN114577747 A CN 114577747A
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- light intensity
- intensity detector
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- 238000010521 absorption reaction Methods 0.000 title claims abstract description 41
- 238000000034 method Methods 0.000 title claims abstract description 16
- 230000031700 light absorption Effects 0.000 claims abstract description 29
- 230000003287 optical effect Effects 0.000 claims description 12
- 229910002601 GaN Inorganic materials 0.000 claims description 5
- JMASRVWKEDWRBT-UHFFFAOYSA-N Gallium nitride Chemical compound [Ga]#N JMASRVWKEDWRBT-UHFFFAOYSA-N 0.000 claims description 5
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims description 5
- 229910010271 silicon carbide Inorganic materials 0.000 claims description 5
- 239000007789 gas Substances 0.000 description 51
- JCXJVPUVTGWSNB-UHFFFAOYSA-N Nitrogen dioxide Chemical compound O=[N]=O JCXJVPUVTGWSNB-UHFFFAOYSA-N 0.000 description 23
- 239000003570 air Substances 0.000 description 21
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 20
- 238000001514 detection method Methods 0.000 description 20
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 18
- RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 description 16
- 238000004519 manufacturing process Methods 0.000 description 10
- 239000004215 Carbon black (E152) Substances 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- MGWGWNFMUOTEHG-UHFFFAOYSA-N 4-(3,5-dimethylphenyl)-1,3-thiazol-2-amine Chemical compound CC1=CC(C)=CC(C=2N=C(N)SC=2)=C1 MGWGWNFMUOTEHG-UHFFFAOYSA-N 0.000 description 3
- YZCKVEUIGOORGS-OUBTZVSYSA-N Deuterium Chemical compound [2H] YZCKVEUIGOORGS-OUBTZVSYSA-N 0.000 description 3
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 3
- 230000003321 amplification Effects 0.000 description 3
- 229910052805 deuterium Inorganic materials 0.000 description 3
- 229930195733 hydrocarbon Natural products 0.000 description 3
- 150000002430 hydrocarbons Chemical class 0.000 description 3
- 238000003199 nucleic acid amplification method Methods 0.000 description 3
- 229910052725 zinc Inorganic materials 0.000 description 3
- 239000011701 zinc Substances 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 229910002089 NOx Inorganic materials 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000002795 fluorescence method Methods 0.000 description 2
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 2
- 229910052753 mercury Inorganic materials 0.000 description 2
- 238000005057 refrigeration Methods 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 239000012080 ambient air Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- LZDVDTNBLCLMGQ-UHFFFAOYSA-N cesium telluride Chemical group [Cs][Te][Cs] LZDVDTNBLCLMGQ-UHFFFAOYSA-N 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000009499 grossing Methods 0.000 description 1
- 230000005283 ground state Effects 0.000 description 1
- 238000004020 luminiscence type Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 229910052724 xenon Inorganic materials 0.000 description 1
- FHNFHKCVQCLJFQ-UHFFFAOYSA-N xenon atom Chemical compound [Xe] FHNFHKCVQCLJFQ-UHFFFAOYSA-N 0.000 description 1
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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
- G01N21/33—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using ultraviolet light
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
- Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
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- Physics & Mathematics (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
The invention discloses an ultraviolet absorption method gas detector, which comprises an ultraviolet light source for emitting ultraviolet light, a light absorption cell arranged behind the ultraviolet light source and provided with a gas inlet and a gas outlet, an absorption light intensity detector arranged at the rear end of the light absorption cell, a light splitting lens arranged between the ultraviolet light source and the light absorption cell, and a background light intensity detector arranged above or below the light splitting lens.
Description
Technical Field
The invention relates to the technical field of environment detection, in particular to an ultraviolet absorption method gas detector.
Background
The gas detector is used for detecting the concentration of a certain gas in a detected gas, in the prior art, a sulfur dioxide detector detects the concentration of the certain gas by an ultraviolet fluorescence method, ultraviolet light sources such as a deuterium lamp and a zinc lamp are used for generating ultraviolet light, then a light filter is used for filtering required ultraviolet light, light is focused by a lens, the detected SO2 gas is removed from carbon-based and hydrocarbon-based gas in the gas by a carbon-hydrocarbon remover and enters a gas chamber, the gas and the ultraviolet light generate fluorescence, a photoelectric tube is used for receiving fluorescence signals and calculating and converting the concentration of the gas by electric signals, wherein the photoelectric tube needs a refrigeration device to keep the temperature of the gas constant, and a light intensity detector is used for carrying out life attenuation detection on the ultraviolet light source.
In the prior art, a detector for detecting nitrogen oxides NO and NO2 in ambient air is used for detecting the nitrogen oxides by a chemiluminescence method, the NO and ozone generate a chemical reaction to generate excited NO2, the excited NO2 emits light when returning to a ground state, the intensity of the emitted light is in direct proportion to the concentration of NO, and then the light intensity is detected by a photoelectric tube to calculate the concentration. The concentration of NO2 is calculated by converting NO2 to NO by a converter and then reacting the NO with ozone by chemiluminescence, wherein the detected concentration is the total amount of nitrogen oxides NOx and the concentration of NO2 is equal to NOx-NO. The NO, NO2 detectors require an ozone generator and a proportional valve, and the photocell requires a refrigeration device to thermostatize it. A NO2 to NO converter is also required.
In the prior art, an ozone detector detects through an ultraviolet absorption method, ultraviolet light is generated through ultraviolet light sources such as a deuterium lamp, a zinc lamp and a low-pressure mercury lamp, light is filtered through an interference filter, ozone can absorb ultraviolet light intensity with specific wavelength, the light intensity is detected through the detector, and the ozone concentration is calculated. When the instrument detects two paths of gas, the detected gas enters the gas chamber to detect a light intensity value I1, then the gas is switched to the other path of gas through the electromagnetic valve, the gas can remove ozone in the gas path through the ozone remover, enters the gas chamber to measure a light intensity signal I0, and then an ozone concentration value is calculated through I0-I1.
These three gas detectors all suffer from several drawbacks, mainly characterized by:
first, the ultraviolet band required by the sulfur dioxide and ozone detectors to generate fluorescence and absorb is unique. Therefore, ultraviolet light emitted by the ultraviolet light source has certain requirements on the wave band, and the light filter is required to participate in the wave band to obtain the desired wave band.
The sulfur dioxide detector has high requirements on an optical path, a full convex lens for focusing and a semi-convex lens for smoothing are required in the detector, the requirements on the optical path design and processing are high, and the detected gas needs to be removed by a carbon-based and hydrocarbon-based gas in the gas through a hydrocarbon remover. Moreover, the removal of the material is basically monopolized abroad, and the use cost is very high. The photoelectric detection tube for sulfur dioxide has high requirements on the use environment, and the photoelectric detection tube must be kept at a constant temperature to ensure the stability of the photoelectric detection tube. And the detection signal is very weak, so that the requirement on signal amplification and noise processing of a hardware circuit is very high.
Third, the nitrogen oxide detector must have ozone participation to produce luminescence reaction, ozone generator must be used to produce ozone, the produced ozone must enter the reaction chamber according to a certain proportion, a proportional valve is also needed, NO2 detection, NO2 must be converted into NO through a converter, NOx value is measured, and then calculation is carried out. The photoelectric detection tube has high requirements on the use environment, and the photoelectric detection tube must be kept at a constant temperature to ensure the stability of the photoelectric detection tube. And the detection signal is very weak, so that the requirement on signal amplification and noise processing of a hardware circuit is very high.
And fourthly, the gas circuit of the ozone detector has to be a gas circuit with two paths of gases which are continuously switched through an electromagnetic valve, the measured values are differentiated to obtain concentration values, one path of gas passes through an ozone eliminator to eliminate ozone, the eliminator is monopolized abroad and is a consumable which needs to be replaced periodically, and the use cost is higher. The photoelectric detection tube has high requirements on the use environment, and the stability of the photoelectric detection tube needs to be ensured by keeping the photoelectric detection tube at a constant temperature. And the detection signal is very weak, so that the requirement on signal amplification and noise processing of a hardware circuit is very high.
The existing gas detectors are complex in structure, multiple in used components and high in use environment requirement, if other gas components or environment influence exists, the detection signals are greatly influenced, and the production of the detectors has high requirements on quality of production personnel, high production cost and low production efficiency.
Disclosure of Invention
The invention aims to provide an ultraviolet absorption method gas detector, which adopts the technical scheme that: the utility model provides a gas detector of ultraviolet absorption method, it includes the ultraviolet light source that is used for launching ultraviolet light, sets up the light absorption cell who has air inlet and gas outlet behind the ultraviolet light source, sets up the absorption light intensity detector at the light absorption cell rear end, its characterized in that: the device also comprises a light splitting lens arranged between the ultraviolet light source and the light absorption cell, and a background light intensity detector arranged above or below the light splitting lens.
The invention is further characterized in that:
the light absorption cell is a common optical path light cell or a long optical path light cell.
The sensors in the body light intensity detector and the absorption light intensity detector adopt a silicon carbide sensor or a gallium nitride sensor.
The ultraviolet light source is an LED ultraviolet lamp which emits ultraviolet light with the central wavelength of 254nm or 405nm or 200nm or 280 nm.
The LED ultraviolet lamp is provided with an LED ultraviolet lamp fixing seat, and the background light intensity detector and the absorption light intensity detector are also respectively provided with a background light intensity detector fixing seat and an absorption light intensity detector fixing seat.
The light absorption cell comprises a front air inlet seat, a rear air outlet seat and a light cell fixedly connected between the front air inlet seat and the rear air outlet seat through a pressure plate, wherein the spectroscope is arranged on the front air inlet seat.
The invention has the beneficial effects that:
the light path is divided into two paths by the light splitting lens, one path detects the light intensity value of the LED ultraviolet lamp as I0 through the background light intensity detector, the other path detects the light intensity value as I1 through the gas in the light absorption cell, and the concentration value of the detected gas is converted by I0-11. The structure saves complicated light path design and light path treatment, eliminates the influence of gas components and working environment on the structure, can achieve a simpler structure, uses fewer components and parts, has lower manufacturing cost, has low quality requirement of production personnel, and can greatly improve the production efficiency.
Drawings
FIG. 1 is a schematic diagram of an optical path and an air path according to a first embodiment of the present invention;
FIG. 2 is a schematic diagram of an optical path and an air path according to a second embodiment of the present invention;
fig. 3 is an exploded view of a third embodiment of the present invention.
Detailed Description
The invention is described in further detail below with reference to the accompanying drawings:
the first embodiment is as follows:
as shown in fig. 1: a gas detector by an ultraviolet absorption method comprises an ultraviolet light source 1 for emitting ultraviolet light, a light absorption cell 3 which is arranged behind the ultraviolet light source and is provided with an air inlet 301 and an air outlet 302, an absorption light intensity detector 5 arranged at the rear end of the light absorption cell 3, a light splitting lens 2 arranged between the ultraviolet light source 1 and the light absorption cell 3, and a background light intensity detector 4 arranged below the light splitting lens 2. In this embodiment, the light absorption cell 3 is a common optical path light cell, the sensors in the body light intensity detector 4 and the absorption light intensity detector 5 are silicon carbide sensors or gallium nitride sensors, and the ultraviolet light source 1 is an LED ultraviolet lamp emitting ultraviolet light with a central wavelength of 254nm or 405nm or 200nm or 280 nm.
The specific working process is as follows: when the detection is started, the LED ultraviolet lamp 1 emits ultraviolet light, the light is divided into two light rays through the light splitting lens 2, one light ray irradiates the background light intensity detector 4, the light intensity value measured by the background light intensity detector 4 is I0, the gas enters the light absorption cell 3 from the gas inlet 301, then the gas flows out through the gas outlet 302 on the light absorption cell 3, the other light ray generates spectrum absorption through the gas in the light absorption cell 3 and the light absorption cell, the light intensity value I1 after the gas absorption is measured by the absorption light intensity detector 5, and the gas concentration value is calculated through conversion by using I0-I1.
In practical application, when the light splitting lens 2 is placed to split ultraviolet light emitted by the LED ultraviolet lamp upwards, the background light intensity detector 4 is arranged above the light splitting lens 2.
Second embodiment:
as shown in fig. 2, in the present embodiment, the light absorption cell 3 is a long-path light cell. The rest is the same as the first embodiment.
The third embodiment:
as shown in fig. 3, an ultraviolet absorption method gas detector includes an ultraviolet light source 1 for emitting ultraviolet light, a light absorption cell 3 with an air inlet 301 and an air outlet 302 arranged behind the ultraviolet light source, an absorption light intensity detector 5 arranged at the rear end of the light absorption cell 3, a light splitting lens 2 arranged between the ultraviolet light source 1 and the light absorption cell 3, and a background light intensity detector 4 arranged below the light splitting lens 2. In this embodiment, the light absorption cell is a common optical path light cell, the sensors in the body light intensity detector 4 and the absorption light intensity detector 5 are silicon carbide sensors or gallium nitride sensors, and the ultraviolet light source 1 is an LED ultraviolet lamp. Wherein the LED ultraviolet lamp is provided with an LED ultraviolet lamp fixing seat 101, the background light intensity detector 4 and the absorption light intensity detector 5 are also respectively provided with a background light intensity detector fixing seat 401 and an absorption light intensity detector fixing seat 501: the light absorption cell 3 comprises a front air inlet seat 303 with an air inlet 301, a rear air outlet seat 304 with an air outlet 302, and a light cell 306 fixedly connected between the front air inlet seat 303 and the rear air outlet seat 304 through a pressure plate 305, wherein the spectroscope 2 is arranged on the front air inlet seat 303, the LED ultraviolet lamp fixing seat 101, the background light intensity detector fixing seat 401 and the front air inlet seat 303 are connected together through screws or bolts or other connecting pieces, and the rear air outlet seat 304 and the absorption light intensity detector fixing seat 501 are connected together through screws or bolts or other connecting pieces.
The light path is divided into two paths by the light splitting lens, one path detects the light intensity value of the LED ultraviolet lamp as I0 through the background light intensity detector, the other path detects the light intensity value as I1 through the gas in the light absorption cell, and the concentration value of the detected gas is converted by I0-11. The structure saves complex light path design and light path treatment, eliminates the influence of gas components and working environment on the structure, can achieve a simpler structure, uses fewer components, has lower manufacturing cost, has low requirement on quality of production personnel, can greatly improve production efficiency, more importantly, has lower system signal-to-noise ratio due to larger noise of the original ultraviolet light source and the absorption light intensity detector, so that in low-concentration detection, the ultraviolet absorption method is replaced by a chemiluminescence method and an ultraviolet fluorescence method, the ultraviolet light source in the prior art comprises a flash xenon lamp, a deuterium lamp, a zinc lamp and a mercury lamp, the light sources are all broad-spectrum light sources, the signal noise is larger, in addition, an optical filter is required to be added, and the optical filter is greatly influenced by the environment; the LED light source is adopted, the broad spectrum is narrow, constant current driving and constant temperature control are assisted, and the noise of the light source is obviously reduced; in addition, the sensor in the light intensity absorption detector in the prior art is cesium telluride or silicon sensor, the dark current and noise are large, the background light intensity detector and the sensor in the light intensity absorption detector both adopt silicon carbide or gallium nitride sensors, the noise is reduced by a plurality of orders of magnitude, and the signal-to-noise ratio of the system is greatly improved by improving the ultraviolet light source and the sensor in the detector, so that the invention ensures that the detection of the concentration of nitric oxide, nitrogen dioxide and sulfur dioxide gas is the same as the detection of the concentration of ozone gas and can detect the concentration by an ultraviolet absorption method.
In practical application, the ultraviolet LED lamp is used for measuring the concentration of ozone, the concentration of nitric oxide, the concentration of nitrogen dioxide and the concentration of sulfur dioxide, and when the ultraviolet LED lamp is used for measuring the concentration of ozone, the ultraviolet LED lamp emitting ultraviolet light with the central wavelength of 254nm is adopted as the ultraviolet LED lamp; when the device is used for measuring the concentration of nitrogen dioxide, the LED ultraviolet lamp emits ultraviolet light with the central wavelength of 405 nm; when the device is used for measuring the concentration of nitric oxide, the LED ultraviolet lamp emits ultraviolet light with the central wavelength of 200 nm; when the ultraviolet LED lamp is used for measuring the concentration of sulfur dioxide, the ultraviolet LED lamp emitting ultraviolet light with the central wavelength of 280nm is adopted.
While the invention has been described with respect to the foregoing technical disclosure and features, it will be understood that various changes and modifications in the above-described arrangements, including combinations of features disclosed herein either individually or as claimed, may be suggested to one skilled in the art and are to be included within the spirit and scope of the appended claims. These variations and/or combinations fall within the skill of the art to which the invention pertains and fall within the scope of the claims that follow.
Claims (7)
1. The utility model provides a gas detector of ultraviolet absorption method, it includes the ultraviolet light source that is used for launching ultraviolet light, sets up the light absorption cell who has air inlet and gas outlet behind the ultraviolet light source, sets up the absorption light intensity detector at the light absorption cell rear end, its characterized in that: the device also comprises a light splitting lens arranged between the ultraviolet light source and the light absorption cell, and a background light intensity detector arranged above or below the light splitting lens.
2. The UV absorption gas detector according to claim 1, wherein said light absorption cell is a normal optical path cell or a long optical path cell.
3. The ultraviolet absorption method gas detector according to claim 1 or claim 2, wherein: the sensors in the body light intensity detector and the absorption light intensity detector adopt a silicon carbide sensor or a gallium nitride sensor.
4. The ultraviolet absorption gas detector set forth in claim 3, wherein: the ultraviolet light source is an LED ultraviolet lamp which emits ultraviolet light with the central wavelength of 254nm or 405nm or 200nm or 280 nm.
5. The ultraviolet absorption gas detector set forth in claim 4, wherein: the LED ultraviolet lamp is provided with an LED ultraviolet lamp fixing seat, and the background light intensity detector and the absorption light intensity detector are also respectively provided with a background light intensity detector fixing seat and an absorption light intensity detector fixing seat.
6. The ultraviolet absorption gas detector set forth in claim 5, wherein: the light absorption cell comprises a front air inlet seat with an air inlet, a rear air outlet seat with an air outlet, and a light cell fixedly connected between the front air inlet seat and the rear air outlet seat through a pressure plate, wherein the spectroscope is arranged on the front air inlet seat.
7. The ultraviolet absorption gas detector set forth in claim 6, wherein: the LED ultraviolet lamp fixing seat, the background light intensity detector fixing seat and the front air inlet seat are connected together through a connecting piece, and the rear air outlet seat and the absorption light intensity detector fixing seat are connected together through a connecting piece.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210356509.4A CN114577747A (en) | 2022-04-06 | 2022-04-06 | Gas detector by ultraviolet absorption method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210356509.4A CN114577747A (en) | 2022-04-06 | 2022-04-06 | Gas detector by ultraviolet absorption method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114577747A true CN114577747A (en) | 2022-06-03 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210356509.4A Pending CN114577747A (en) | 2022-04-06 | 2022-04-06 | Gas detector by ultraviolet absorption method |
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| Country | Link |
|---|---|
| CN (1) | CN114577747A (en) |
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2022
- 2022-04-06 CN CN202210356509.4A patent/CN114577747A/en active Pending
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