CN114460037A - Ammonia gas mass laser remote measuring device - Google Patents
Ammonia gas mass laser remote measuring device Download PDFInfo
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- CN114460037A CN114460037A CN202111657945.7A CN202111657945A CN114460037A CN 114460037 A CN114460037 A CN 114460037A CN 202111657945 A CN202111657945 A CN 202111657945A CN 114460037 A CN114460037 A CN 114460037A
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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
- G01N21/39—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using tunable lasers
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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
- G01N21/01—Arrangements or apparatus for facilitating the optical investigation
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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
- G01N21/01—Arrangements or apparatus for facilitating the optical investigation
- G01N21/03—Cuvette constructions
- G01N21/031—Multipass arrangements
- G01N2021/0314—Double pass, autocollimated path
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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
- G01N2021/3513—Open path with an instrumental source
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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
- G01N21/39—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using tunable lasers
- G01N2021/396—Type of laser source
- G01N2021/399—Diode laser
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2201/00—Features of devices classified in G01N21/00
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Abstract
The invention discloses an ammonia gas mass laser telemetering device which can effectively solve the problem that a long-distance toxic and harmful ammonia gas mass is difficult to detect and can realize full-automatic long-distance online monitoring of ammonia gas mass concentration. Including open telemetry optical units, analytical controllers, optical fibers, and coaxial signal lines. The analysis controller comprises a near-infrared tunable diode laser, a laser driver, an MCU, an AD acquisition module and a temperature control unit; the MCU receives the AD acquisition module information and controls the laser driver; the near-infrared tunable diode laser transmits laser and control information to the open type telemetering optical unit through an optical fiber and a coaxial signal line; analog signals detected by an infrared detector in the open type telemetering optical unit are input to the AD acquisition module through a coaxial signal line.
Description
Technical Field
The invention relates to the technical field of gas detection, in particular to an ammonia gas mass laser telemetering device.
Background
Ammonia gas is a nitrogen-containing compound second to the neutral content in atmospheric constituents and is also the most abundant basic trace gas in atmospheric constituents. Ammonia gas is also a toxic gas with pungent smell, and high-concentration ammonia gas can cause harm to people, animals and plants and is one of the pollution sources of the atmosphere. In industrial combustion, NH3As a reducing agent, the pollutant NOx in the smoke is converted into non-pollutant by utilizing a selective reduction technology, thereby reducing the pollutionEmission of pollutants NOx. But excess NH3Air pollution can be caused, and simultaneously, the escaped NH is generated3Can react with sulfate produced in the process flow to produce ammonium sulfate salt, which can cause serious corrosion to boiler flue parts, thus bringing expensive maintenance cost. Since ammonia gas has both a positive effect and a hazard to humans and the ecological environment, it is very necessary to perform real-time reliable detection thereof. Only by knowing and mastering the concentration information of the ammonia gas in the surrounding environment, the damage caused by the ammonia gas can be effectively avoided, and even the ammonia gas can be utilized to be converted into the beneficial environment for human beings.
The traditional method for detecting ammonia gas is mainly based on chemical technology and experimental analysis of air suction sampling. In recent years, many analytical controllers for ammonia gas in single-point measurement environments have emerged, such as sensors for sensitive materials and sensors of electrochemical type. The rapid development of these sensors has met the need for ammonia detection to some extent, but has its own drawbacks. Firstly, the measurement range of the ammonia gas sensor is small, only the ammonia gas concentration near the contact point can be measured, and the whole ammonia gas concentration condition cannot be reflected. If the large-range detection is required, a sensor array method is needed, and a large number of sensor detection points are used for averaging, so that the method is complex and high in cost. Secondly, the methods are easily influenced by factors such as temperature, humidity, weather and the like in the detection process, and the probes are required to be replaced at intervals at the detection points. And the sensor taking the semiconductor metal oxide as the sensitive material has poor selectivity, and when a plurality of reducing gases exist simultaneously, interference is easily generated, so that the detection of the sensor on the ammonia gas is influenced. In contrast, the measurement of the concentration of ammonia in the surrounding environment by using the absorption spectroscopy technique is a very promising detection technique, which has many incomparable advantages compared with other similar techniques, and the technique can be said to have far-reaching significance in the field of gas detection.
The main advantages of using tunable diode laser spectrum sensing Technology (TDLAS) to detect gases are: the detection range is large, and the monitoring distance can be from several meters to thousands of meters by adopting an open optical path mode; the detection precision is high, and the detection limit of gas concentration is lower than one millionth); the selectivity is high, and the interference of other gases can be effectively avoided by selecting a proper laser spectrum waveband; the method is a completely non-contact on-line automatic monitoring technology, and is safer and more reliable compared with other technologies; the response speed is high, and the response time is second, so that the change of the gas concentration can be monitored in real time; the device is not easily influenced by the climatic environment, and does not need manual real-time care; convenient installation, easy upgrading and the like. Therefore, the detection method based on the tunable diode laser spectrum sensing technology is the development direction and the main technological flow of the current gas online monitoring technology research, and the application is very wide. Compared with an extraction type system, the open type remote measuring system is really monitoring the ambient air of the factory boundary.
How to apply the tunable diode laser spectrum sensing technology to the laser telemetering of the ammonia gas mass is a technical problem which is not solved at present.
Disclosure of Invention
In view of the above, the invention provides an ammonia gas mass laser telemetering device, which can combine the advantages of a tunable diode laser spectrum sensing technology to detect gas, provide a device capable of effectively solving the problem that a long-distance toxic and harmful ammonia gas mass is difficult to detect, and realize full-automatic long-distance online monitoring of ammonia gas mass concentration.
In order to achieve the purpose, the technical scheme of the invention is as follows: the laser telemetering device for ammonia gas mass comprises an open telemetering optical unit, an analysis controller, an optical fiber and a coaxial signal wire.
The analysis controller comprises a near-infrared tunable diode laser, a laser driver, an MCU, an AD acquisition module and a temperature control unit; the laser drives the near-infrared tunable diode laser to work, and the temperature control unit controls the internal temperature of the near-infrared tunable diode laser; the MCU receives the AD acquisition module information, and the MCU controls the laser driver; the near-infrared tunable diode laser transmits laser and control information to the open type telemetering optical unit through an optical fiber and a coaxial signal line; analog signals detected by an infrared detector in the open type telemetering optical unit are input to the AD acquisition module through a coaxial signal line.
The open telemetry optical unit comprises a transmitting end and a reflecting end; the transmitting end comprises a long-tube telescope, a primary reflector, a secondary reflector, an optical window sheet, a spectroscope, a focusing mirror, a beam expanding mirror, an optical fiber and an infrared detector; the reflecting end is a corner reflector array;
the front end of the emission end is an open part, the rear end of the emission end is a sealed part, the open part and the sealed part are separated by the main reflector, the sealed part adopts a metal shell, and nitrogen is filled in the sealed part; the beam expanding lens, the spectroscope, the focusing lens, the optical fiber and the infrared detector are positioned in the sealing part; the optical window is positioned at the central opening of the main reflector; the long-tube telescope is arranged on the upper end surface of the metal shell of the sealing part and used for adjusting the collimation of the transmitting end and the reflecting end, and the light spots appearing at the reflecting end of the opposite surface are observed during adjustment, and the brighter the light spots, the higher the collimation degree of the laser beam irradiating the reflecting end is; the primary reflector and the secondary reflector form a Cassegrain telescope which is used for emitting and collecting infrared laser; the spectroscope is arranged at the rear end of the optical window and is coaxially arranged with the secondary reflector and the optical window; the optical fiber and the coaxial signal line are coaxial with the spectroscope and the beam expander; the lower end of the spectroscope is provided with a focusing mirror and an infrared detector, and the output end of the infrared detector is a coaxial signal line.
The infrared detector is arranged below the spectroscope, a focusing lens is arranged between the spectroscope and the beam expander, and an included angle of 90 degrees is formed between the focusing lens and the beam expander, and the infrared detector is used for detecting infrared laser signals returned by the ammonia gas mass.
The spectroscope is used for reflecting the infrared laser with the ammonia gas mass concentration information into the infrared detector.
Preferably, the laser telemetry device further comprises a base and a base adjustment bracket. The base is fixed on the horizontal installation table-board and is connected with the open telemetering optical unit through the base adjusting bracket. The base adjusting bracket is fixed below the open type telemetering optical unit and used for placing the open type telemetering optical unit and adjusting the open type telemetering optical unit in the horizontal direction and the vertical direction.
Preferably, the beam expander is used for diverging the laser beam emitted by the near-infrared laser, so as to be conveniently emitted by the Cassegrain telescope.
Preferably, the focusing mirror is used to focus the laser beam emitted back through the reflecting end.
Preferably, the spectroscope is coated with a semi-transparent and semi-reflective film in the near infrared band.
Further, the main reflector and the secondary reflector both adopt a single-point diamond processing technology, and the surfaces of the main reflector and the secondary reflector are plated with gold; the primary reflector is a concave paraboloid reflector with a hole in the center, and the secondary reflector is a convex reflector with secondary curvature; the secondary reflector is arranged in front of the central opening of the main reflector.
Further, a wavelength modulation technology is adopted in the analysis controller, second harmonic signals corresponding to standard ammonia gas from low concentration to high concentration are measured, signal fitting of the spectrum is carried out through a least square method, a fitted curve is used for measuring gas with unknown concentration, and brightness and temperature algorithm compensation is carried out so as to invert the column concentration of the ammonia gas mass.
Has the advantages that:
in response to the above-identified deficiencies in the art or needs for improvement, the present invention provides an ammonia gas bolus laser telemetry device. The device can be widely used for detecting the ammonia gas mass in the open space environment such as the field, the factory, the workshop and the like, is provided with different reflectors, the farthest distance of the optical path can reach 1000 meters, and the lower detection limit can reach ppb level.
The invention adopts absolute measurement of direct absorption, and a reference gas module is arranged in the system, so that the absorption spectrum line of gas is locked in real time, the system is always in a real-time correction state and is not influenced by temperature, a power supply and aging of system components, the system does not have the problem of drift, and any regular correction is not needed.
The method adopts a wavelength modulation technology, measures second harmonic signals corresponding to standard ammonia gas from low concentration to high concentration for multiple times, performs signal fitting of spectra through a least square method, and fits a curve to measure gas with unknown concentration and perform brightness and temperature algorithm compensation so as to invert the column concentration of the ammonia gas mass.
Drawings
FIG. 1 is a schematic structural diagram of an ammonia gas mass laser telemetering device provided by an embodiment of the invention;
fig. 2 is an open type telemetry optical unit of the ammonia gas bolus laser telemetry device provided by the embodiment of the invention.
Detailed Description
The invention is described in detail below by way of example with reference to the accompanying drawings.
The invention relates to an ammonia gas mass laser telemetering device, which comprises the following parts: 1) an open telemetry optical unit, consisting of two parts: a transmitting end (telescope) and a reflecting end; 2) an analysis controller; 3) the optical fiber, coaxial signal line, connection analysis controller and open telemetering optical unit. The telemetering device uses a near-infrared tunable diode laser as a light source, high-frequency narrow-band scanning is generated through real-time changing temperature and injected current, a narrow-band scanning laser beam generated by the laser is transmitted to an open telemetering optical unit through an optical fiber, a laser beam transmitted by a transmitting end (telescope) passes through a gas to be detected, is reflected by a reflecting end and then is focused to an infrared detector through the transmitting end (telescope), the infrared detector transmits an absorption spectrum analog signal back to an analysis controller through a coaxial cable, and the analysis controller obtains the concentration of the gas to be detected through analysis and calculation of a scanning absorption spectrum.
As shown in fig. 1, an ammonia gas bolus laser telemetering device 1 comprises a near-infrared tunable diode laser 2, the near-infrared tunable diode laser 2 is packaged in a butterfly package, the near-infrared tunable diode laser 2 is placed in an analysis controller 3 and is connected with an open telemetering optical unit through an optical fiber 4, the analysis controller 3 comprises the near-infrared tunable diode laser 2, an MCU5 and an AD acquisition module 6, the MCU5 controls a built-in temperature control unit 7 and a laser driver 8 in the tunable diode laser 2 to lock the center wavelength output by the laser at 1531.7nm, and transmits a laser with a specific center wavelength to the open telemetering optical unit 9 through the optical fiber, the open telemetering optical unit 9 transmits an infrared laser detection signal with ammonia gas bolus concentration to the AD acquisition module 6 through a coaxial signal line 10, and analyzed by the MCU5 for ammonia gas mass concentration information.
As shown in fig. 2, the open type telemetry optical unit 9 is a main body of the ammonia gas mass laser telemetry device 1, and adopts a metal shell, and nitrogen is filled inside the metal shell, so that the inner lens of the metal shell is not polluted, and the whole instrument has longer service life. The open type telemetering optical unit 9 comprises a beam expander 11 for increasing the divergence angle of laser emitted by the near-infrared tunable diode laser 2, the diverged laser penetrates through a sapphire optical window sheet 12, then passes through a Cassegrain telescope consisting of a secondary reflector 13 and a primary reflector 14, passes through an ammonia gas mass to be detected, returns to the Cassegrain telescope through an angle reflector array 15 and the original path of the optical path, and is focused to an infrared detector 18 through a focusing mirror 17 after being turned by 90 degrees through a 45-degree spectroscope 16.
The main reflector 12 and the secondary reflector 11 are made of aviation aluminum alloy and single-point diamond, and have gold-plated surfaces, surface roughness of less than 30nm, RMS (root mean square)/4, reflectivity of 95 percent and high corrosion resistance. The primary reflector 12 is a parabolic reflector, the curvature radius is-508 mm, the diameter of the mirror surface is 106mm, the secondary reflector 11 is a hyperboloid reflector, the curvature radius is-198 mm, the diameter of the mirror surface is 36mm, and single-point diamond machining technology is adopted and gold is plated on the surface. The infrared detector 18 adopts a secondary refrigeration pyroelectric detector, so that the detection precision of the gas is improved.
The base adjusting bracket 19 is fixed below the open type telemetering optical unit and used for placing the open type telemetering optical unit 9 to adjust in the horizontal direction and the vertical direction, and the long-tube telescope 20 is arranged above the open type telemetering optical unit 9 and used for adjusting the collimation of the open type telemetering optical unit 9.
In the embodiments, the application of the ammonia gas mass laser telemetering device of the present invention is not limited to an ammonia gas analyzer, but can also be applied to other gas analysis equipment.
In the invention, as a preferred scheme, the near-infrared tunable diode laser is packaged into a butterfly package, a thermistor and a semiconductor refrigerator are arranged in the near-infrared tunable diode laser, the central wavelength output by the laser is locked at 1531.7nm by temperature regulation when an ammonia gas mass is detected, and the near-infrared tunable diode laser has the characteristics of long service life and good stability.
In the invention, as a preferred scheme, the long-tube telescope adopts an anti-seismic cross sighting telescope and a built-in level meter, the amplification is 8 times, and the observation can be carried out for 2km farthest.
In the invention, as a preferred scheme, the main reflector and the secondary reflector both adopt a single-point diamond processing technology, and the surfaces of the main reflector and the secondary reflector are plated with gold, so that the reflecting rate is high, the stability is good, and the environmental adaptability is strong.
In the invention, as a preferred scheme, the window sheet is made of sapphire material, and the optical characteristics of the sapphire material have the advantages of high transmittance, good stability, no deliquescence and the like.
In the invention, as a preferred scheme, a 45-degree unilateral high-pass dichroic spectroscope is selected as the spectroscope, and the emitted near-infrared laser and the reflected laser with ammonia concentration information are in the same optical path.
In the invention, as a preferable scheme, the focusing lens and the beam expanding lens adopt an optical glass lens plated with a near-infrared high-transmittance film.
In the invention, as a preferred scheme, the infrared detector adopts a two-stage refrigeration pyroelectric detector, so that the detection precision and sensitivity of gas are improved.
In the invention, as a preferable scheme, the reflecting end adopts a corner reflector array, and laser incident within a certain angle can be reflected back in a large area according to the original opposite direction.
In the invention, as a preferred scheme, the transmitting end of the open type telemetering optical unit is a Cassegrain telescope consisting of a main reflector and a secondary reflector, has the advantages of no chromatic aberration, capability of correcting coma aberration of a paraboloid and the like, and has a more compact structure without adjusting an optical axis.
The invention adopts absolute measurement of direct absorption, and a reference gas module is arranged in the system, so that the absorption spectrum line of gas is locked in real time, the system is always in a real-time correction state and is not influenced by temperature, a power supply and aging of system components, the system does not have the problem of drift, and any regular correction is not needed.
The method adopts a wavelength modulation technology, measures second harmonic signals corresponding to standard ammonia gas from low concentration to high concentration for multiple times, performs signal fitting of spectra through a least square method, and fits a curve to measure gas with unknown concentration and perform brightness and temperature algorithm compensation so as to invert the column concentration of the ammonia gas mass.
The invention can be widely used for detecting ammonia gas clusters in open space environments such as fields, factories, workshops and the like, different reflectors are arranged, the maximum distance of the optical path can reach 1000 meters, and the lower detection limit can reach ppb level.
In summary, the above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (7)
1. The ammonia gas bolus laser telemetering device is characterized by comprising an open telemetering optical unit (9), an analysis controller (3), an optical fiber (4) and a coaxial signal line (10);
the analysis controller comprises a near-infrared tunable diode laser (2), a laser driver (8), an MCU (5), an AD acquisition module (6) and a temperature control unit (7); the MCU (5) receives the information acquired by the AD acquisition module (6) and controls the laser driver (8) to drive the near-infrared tunable diode laser (2) to work; the near-infrared tunable diode laser (2) transmits laser and control information to an open type telemetering optical unit (9) through an optical fiber (4) and a coaxial signal line (10); an analog signal detected (18) by an infrared detector in an open type telemetering optical unit (9) is input to an AD acquisition module (6) through a coaxial signal line (10);
the open telemetry optical unit (9) comprises a transmitting end and a reflecting end; the transmitting end comprises a long-tube telescope (20), a primary reflector (14), a secondary reflector (13), an optical window sheet (12), a spectroscope (16), a focusing mirror (17), a beam expander (11), an optical fiber and an infrared detector (18); the reflecting end is a corner reflector array (15);
the front end of the transmitting end is an open part, the rear end of the transmitting end is a sealing part, the open part and the sealing part are separated by a main reflecting mirror (14), the sealing part adopts a metal shell, and nitrogen is filled in the sealing part; the beam expanding lens (11), the spectroscope (16), the focusing lens (17), the optical fiber and the infrared detector (18) are positioned in the sealing part; the optical window (12) is positioned at the central opening of the main reflector (14); the long-tube telescope (20) is arranged on the upper end surface of the metal shell of the sealing part and used for adjusting the collimation of the transmitting end and the reflecting end, and the light spots appearing at the reflecting end of the opposite surface are observed during adjustment, and the brighter the light spots, the higher the collimation degree of the laser beam irradiating the reflecting end is; the primary reflector (14) and the secondary reflector (13) form a Cassegrain telescope which is used for emitting and collecting infrared laser; the spectroscope (16) is arranged at the rear end of the optical window (12) and is coaxially arranged with the secondary reflector (13) and the optical window (12); the rear end of the spectroscope (16) is provided with a beam expander (11), and the rear end of the beam expander (11) leads out an optical fiber (4); the lower end of the spectroscope (16) is provided with a focusing mirror (17) and an infrared detector (18), and the output end of the infrared detector (18) leads out a coaxial signal line (10); the infrared detector (18) is arranged below the spectroscope (16), a focusing lens (17) is arranged between the spectroscope and the spectroscope, and forms an included angle of 90 degrees with the optical axis of the beam expanding lens (11) and is used for detecting infrared laser signals returned by the ammonia gas mass;
the spectroscope (16) is used for reflecting the infrared laser with the ammonia gas mass concentration information into an infrared detector (18).
2. An ammonia gas mass laser telemetry device as claimed in claim 1 wherein the laser telemetry device further comprises a base and a base adjustment bracket;
the base is fixed on the horizontal mounting table surface and is connected with the open type telemetering optical unit (9) through a base adjusting bracket;
the base adjusting bracket is fixed below the open type telemetering optical unit (9) and used for placing the open type telemetering optical unit (9) and adjusting the open type telemetering optical unit in the horizontal direction and the vertical direction.
3. The ammonia gas mass laser telemetry device of claim 1, wherein the beam expander is configured to expand the laser beam emitted by the near-infrared laser for subsequent transmission through the cassegrain telescope.
4. The ammonia gas mass laser telemetry device of claim 1, characterized in that the focusing mirror (17) is used to focus the laser beam emitted back through the reflecting end.
5. The ammonia gas bolus laser telemetering device according to claim 1, wherein the spectroscope (16) is coated with a semi-transparent and semi-reflective film in the near infrared band.
6. The ammonia gas mass laser telemetering device according to claim 1, wherein the primary reflector (14) and the secondary reflector (13) are both made by single-point diamond machining, and the surfaces of the primary reflector and the secondary reflector are plated with gold; the main reflector (14) is a concave paraboloid reflector with a hole at the center, and the secondary reflector (13) is a convex reflector with secondary curvature; the secondary reflector (13) is arranged in front of a central opening of the main reflector (14).
7. The ammonia gas mass laser telemeter according to claim 1, wherein a wavelength modulation technique is adopted in the analysis controller to measure a second harmonic signal corresponding to standard ammonia gas from low concentration to high concentration, a least square method is used for spectral signal fitting, and a fitted curve is used for measuring gas with unknown concentration, and brightness and temperature algorithm compensation is performed to invert the column concentration of the ammonia gas mass.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115420697A (en) * | 2022-11-03 | 2022-12-02 | 北京云端光科技术有限公司 | Laser telemetering transceiver |
| CN115791699A (en) * | 2023-02-08 | 2023-03-14 | 山东星冉信息科技有限公司 | Methane remote measuring alarm system and method based on vertical cavity surface emission and storage medium |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5373160A (en) * | 1993-05-04 | 1994-12-13 | Westinghouse Electric Corporation | Remote hazardous air pullutants monitor |
| CN101021474A (en) * | 2006-12-05 | 2007-08-22 | 中国科学院安徽光学精密机械研究所 | Opening gas multi-element monitoring instrument and monitoring method |
| CN104132911A (en) * | 2014-08-04 | 2014-11-05 | 中国科学院合肥物质科学研究院 | Open type long optical distance CO and CH4 online testing instrument |
| CN104568834A (en) * | 2015-01-08 | 2015-04-29 | 天津大学 | TDLAS-based ammonia gas detection experiment system |
-
2021
- 2021-12-31 CN CN202111657945.7A patent/CN114460037A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5373160A (en) * | 1993-05-04 | 1994-12-13 | Westinghouse Electric Corporation | Remote hazardous air pullutants monitor |
| CN101021474A (en) * | 2006-12-05 | 2007-08-22 | 中国科学院安徽光学精密机械研究所 | Opening gas multi-element monitoring instrument and monitoring method |
| CN104132911A (en) * | 2014-08-04 | 2014-11-05 | 中国科学院合肥物质科学研究院 | Open type long optical distance CO and CH4 online testing instrument |
| CN104568834A (en) * | 2015-01-08 | 2015-04-29 | 天津大学 | TDLAS-based ammonia gas detection experiment system |
Non-Patent Citations (3)
| Title |
|---|
| 何莹等: "奥运期间北京城区的开放式NH_3激光在线监测", 《大气与环境光学学报》 * |
| 原辉等: "天然气泄漏开放式激光遥测技术研究", 《工业安全与环保》 * |
| 姜治深等: "基于可调谐半导体激光吸收光谱技术的甲烷遥测方法的研究", 《能源工程》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115420697A (en) * | 2022-11-03 | 2022-12-02 | 北京云端光科技术有限公司 | Laser telemetering transceiver |
| CN115791699A (en) * | 2023-02-08 | 2023-03-14 | 山东星冉信息科技有限公司 | Methane remote measuring alarm system and method based on vertical cavity surface emission and storage medium |
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