CN207147951U - A kind of absorption cell for gas detection - Google Patents
A kind of absorption cell for gas detection Download PDFInfo
- Publication number
- CN207147951U CN207147951U CN201720864607.3U CN201720864607U CN207147951U CN 207147951 U CN207147951 U CN 207147951U CN 201720864607 U CN201720864607 U CN 201720864607U CN 207147951 U CN207147951 U CN 207147951U
- Authority
- CN
- China
- Prior art keywords
- fiber optic
- module
- absorption cell
- cavity
- light
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
The utility model discloses a kind of absorption cell for gas detection, it includes：Fiber optic collimator module, focus module, the cavity between fiber optic collimator module and focus module, wherein fiber optic collimator module include optical fiber collimator, accurate light modulation structure, fiber optic collimator module fixing end；Include condenser lens, focus module fixing end, the optical axis of the condenser lens and the central axis of cavity air chamber, the optical axis coincidence of fiber optic collimator module in focus module；The both ends of cavity respectively with fiber optic collimator module fixing end and focus module fixing end airtight connection, the hollow space of cavity is the air chamber for accommodating under test gas, its side is provided with air inlet and gas outlet, and top is provided with screw and is used to install at least one sensor for detecting the parameters such as the temperature and pressure of air chamber.The gas absorption cell have the advantages that volume is small, light path is short, it is simple in construction, be easily installed debugging and safeguard, available for detection ppm levels Gases Dissolved in Transformer Oil.
Description
Technical field
The utility model belongs to precision detecting instrument field, and in particular to a kind of absorption cell for gas detection, especially
It is related to a kind of gas absorption cell that can be used for detection Gases Dissolved in Transformer Oil.
Background technology
It is more and more extensive using the application of the technology of spectroscopy measurements one-component or multicomponent gas in the industry.Than
As laser spectrum measuring instrument can be used for monitoring Gases Dissolved in Transformer Oil.Due to " fingerprint " characteristic that gas absorbs, light exists
After the absorption cell full of detected gas, the light of some single-frequency is absorbed by gas in pond, and single-frequency reflects
Gas componant, the change of single-frequency light intensity then reflect the concentration of detected gas.The detection process of this gas componant, extensively
It is general to be applied to industrial production and environmental monitoring.Many detection techniques are presently, there are, it is infrared in mainly using and near red
External spectrum detection technique.Due to the cross-sectional area very little that gas absorbs, so generally requiring by increasing light path to improve gas
Detection sensitivity.
The gas absorption cell of prior art, mainly there are long light path pond and the class of adjustable optical path pool two.Long light path pond, by inhaling
Receives pond inner plenum places multi-disc speculum so that and light completes multiple reflections in air chamber, increases light path using short distance,
Improve detection sensitivity.The structure of adjustable optical path pool is substantially with long light path pond, the difference is that can be controlled by adjusting order of reflection
The change of light path processed.Both of which is to reach target detection sensitivity by controlling light path.
Optical element in long light path pond and adjustable optical path pool is more, and light modulation structure is complicated so that its volume is relatively large.
In addition, long light path pond and adjustable optical path pool require high to the coating process of speculum, the difficult in maintenance and cost of installation is high, anti-vibration resistance
Difference, thus environmental suitability is poor.
Utility model content
To solve the above mentioned problem in the long light path pond of prior art and adjustable optical path pool, the utility model provides a kind of little Rong
The short light path gas absorption cell of product, the small short light path gas absorption cell of volume change the labyrinth in existing long light path pond, gram
The defects of having taken that light path adjustment difficulty is big, shock resistance is poor etc..Concrete technical scheme is as follows.
A kind of gas absorption cell for gas detection, it includes：For the fiber optic collimator for being collimated the light of light source
Module, it is accurate positioned at optical fiber for the focus module for being focused and making focusing light to be emitted after collimation by the light of cavity air chamber
The directly cavity between module and focus module, for introducing and discharging under test gas, wherein, the fiber optic collimator module includes light
Fine collimater, the accurate light modulation structure for adjusting light path, for by accurate light modulation structure and cavity one end is closed is fixed on one
The collimation lens end of the fiber optic collimator module fixing end risen, wherein optical fiber collimator is inserted in the central through hole of accurate light modulation structure
It is and fixed；Include condenser lens in the focus module, for fixed focus lenses and with the cavity other end is closed is fixed on
Focus module fixing end together, the optical axis of the condenser lens and the central axis of cavity air chamber, the optical axis of fiber optic collimator module
Overlap；The both ends of the cavity respectively with fiber optic collimator module fixing end and focus module fixing end airtight connection, in cavity
Empty part is the air chamber for accommodating under test gas, and the light beam after collimation is transferred to focus module by air chamber, and its side is provided with
Air inlet and gas outlet, and connecting hole such as screw and/or jack are such as provided with top in air chamber wall and is used to be attached to
A few sensor, preferably two or more sensor are used for detecting the parameters such as the temperature and pressure of air chamber, so as to for detection
As a result it is modified.
Due to not including the speculum for being used for realizing light reflection in gas absorption cell so that gas absorption cell is simple in construction,
It is easy to install dismounting and repeatedly installing/dismounting can't influence accuracy of detection, this simple structure without speculum enhances gas
The shock resistance and environmental suitability of absorption cell, while the air chamber structure of through type, short light path designs and the air chamber of absorption cell is held
Product is small, correspondingly reduces the volume of gas absorption cell.Preferably, gas absorption cell can reach under the conditions of small volume, short light path
To very high accuracy of detection, such as the application in Gases Dissolved in Transformer Oil detection, advised better than national grid company standard
Fixed minimum detection limit.
According to one side of the present utility model, the light of above-mentioned light source can be any light available for detection gas, ripple
Long scope is 200-6000nm, preferably 200-1800nm, including but not limited to visible ray, ultraviolet light, infrared light and/or near-infrared
Light.Further, it is preferable to the just laser from light source transmitting.
According to one side of the present utility model, the fiber optic collimator module also includes fiber optic collimator module protection shell, uses
To cover optical fiber collimator, accurate light modulation structure, fiber optic collimator module fixing end, protect these parts not by external environment and thing
The influence of body.
According to one side of the present utility model, above-mentioned gas absorption cell also includes being used to fix the fiber optic collimator module
The first support of containment vessel and the cavity front end and the second support for fixing the cavity rear end, the first support
It is connected to a fixed with both ends of the second support respectively with cavity.
Further, gas absorption cell also includes being used for the light inlet for accessing light source.In one embodiment, it is described enter
Optical port is located in first support.For example light inlet is provided with flange, for connecting light source and fiber optic collimator module.
According to one side of the present utility model, light-emitting window (i.e. condenser lens is provided with the focus module fixing end
Exit portal), the optical axis of condenser lens and the central axis of cavity air chamber, the optical axis coincidence of fiber optic collimator module.Such as the light extraction
Mouth is arranged in focus module fixing end.
According to one side of the present utility model, there is central through hole in the fiber optic collimator module fixing end, the center leads to
Oblique window is fixed with hole, for reducing optical standard tool interference.
According to one side of the present utility model, the focus module fixing end rear portion can further connect photodetection mould
Block, the photoelectric detection module is used to receive the light transmitted from the light-emitting window, and is converted to electric signal.
The utility model additionally provides application of the above-mentioned gas absorption cell in gas detection.
According to one side of the present utility model, above-mentioned gas absorption cell can be used for detecting Gases Dissolved in Transformer Oil.
In a preferred embodiment, the Gases Dissolved in Transformer Oil is selected from N2、O2、H2、CH4、C2H2、C2H4、
C2H6、CO、CO2One or both of more than.
The cavity body structure of gas absorption cell of the present utility model is simple, and light path is short, and volume is small so that entirely absorbs pool structure
Compact, air-tightness is good, dismounting easy to install, is easy to safeguard；And with the advantages of shock resistance is good, environment is practical.
Brief description of the drawings
Fig. 1 is the structural representation according to a gas absorption cell embodiment of the present utility model.
Description of reference numerals：1st, gas absorption cell；2nd, fiber optic collimator module；3rd, focus module；4th, cavity；21st, optical fiber is accurate
Straight device；22nd, accurate light modulation structure；23rd, fiber optic collimator module fixing end；24th, first support；25th, fiber optic collimator module protection shell；
241st, light inlet；31st, condenser lens；32nd, light-emitting window；33rd, focus module fixing end；34th, second support；41st, cavity air chamber；
42nd, air inlet；43rd, sensor；44th, bolt；45th, gas outlet.
Embodiment
Below in conjunction with accompanying drawing, the technical solution of the utility model is described.Obviously, described embodiment is only
A part of embodiment of the application, rather than whole embodiments；And the structure shown in accompanying drawing is only schematical,
Material object is not represented.It should be noted that based on these embodiments in the utility model, those of ordinary skill in the art are obtained
The every other embodiment obtained, belong to the scope of the application protection.
In the utility model, term " gas absorption cell " and " absorption cell " represent identical meaning, can exchange.
Herein, term is " preceding " represents along the position in gas absorption cell of the present utility model along the upstream of beam direction
Relation, but be not meant to must be directed towards a certain fixed-direction in actual installation practice, just to show between all parts
Position relationship or annexation.Similarly, term " rear ", " on ", " under " etc. do not form absolute spatial relationship limitation, only
It is a kind of relative concept.This is that those skilled in the art can understand.It is convenient sometimes for being described on word, meet
To accompanying drawing direction, beam direction upstream side is referred to as " left side ", beam direction downstream side referred to as " right side ", it is simply a kind of relative
Concept, this is that those skilled in the art can understand.
Referring to Fig. 1, gas absorption cell 1 of the present utility model mainly includes fiber optic collimator module 2, focus module 3, cavity 4
These three parts.Wherein fiber optic collimator module 2 is used to after the light of light source is collimated be incident in the air chamber 41 of cavity 4, with
Just the under test gas in air supply chamber 41 absorbs.Fiber optic collimator module 2 mainly include optical fiber collimator 21, for adjust light path so as to
Make the light beam accurate light modulation structure 22 coaxial with the optical axis of following condenser lenses 31, for by accurate light modulation structure 22 and cavity 4
The closed fiber optic collimator module fixing end 23 being fixed together in one end (i.e. front end).Preferably, fiber optic collimator module 2 also includes light
Fine collimating module containment vessel 25, the containment vessel 25 are used for covering optical fiber collimator 21, accurate light modulation structure 22, fiber optic collimator module
Fixing end 23, these parts are protected not influenceed by external environment and object.In a preferred embodiment, in order to support
Whole absorption cell 1, the structural stability for keeping absorption cell 1, fiber optic collimator module 2 can also include being used for the front end of fixed cavity 4
With the first support 24 of fiber optic collimator module protection shell 25.Preferably, the collimation lens end insertion of optical fiber collimator 21 is accurate adjusts
It is in the central through hole of photo structure 22 and fixed.In one embodiment, light inlet 241 can be provided with first support 24, is entered
Optical port 241 is provided with flange and is used to connect light source.
Fiber optic collimator module fixing end 23 is provided with central through hole, can be fixed with oblique window in the central through hole, be used for
Reduce optical standard tool interference, ensure gas detection accuracy.
Focus module 3 mainly includes condenser lens 31, for fixed focus lenses 31 and closed solid with the other end of cavity 4
It is scheduled on focus module fixing end 33 together, optical axis and the central axis of cavity air chamber 41, the fiber optic collimator mould of the condenser lens 31
The optical axis coincidence of block 2.In a preferred embodiment, in order to support whole absorption cell 1, keep absorption cell 1 structure it is steady
It is qualitative, the second support 34 of fixation can also be set in the rear end of cavity 4, and first support 24 and second support 34 are solid together
Determine, support whole gas absorption cell.Light-emitting window 32 (i.e. condenser lens exit portal 32) is provided with focus module fixing end 33, is gathered
The optical axis of focus lens 31 and the central axis of cavity air chamber 41, the optical axis coincidence of fiber optic collimator module 2.
The both ends of cavity 4 respectively with fiber optic collimator module fixing end 23 and the airtight connection of focus module fixing end 33, cavity 4
Hollow space be air chamber 41 for accommodating under test gas, the light beam after collimation is transferred to focus module 3, gas by air chamber 41
The side of room 41 is provided with air inlet 42 and gas outlet 45, and is such as provided with connecting hole ratio at top at the suitable position of air chamber wall
As screw and/or jack are used to installing at least one sensor 43, preferably two or more sensor 43 is used for detecting the temperature of air chamber
Degree and pressure parameter, so as to for being modified to testing result.It should be understood that the position of air inlet 42 and gas outlet 45 can root
Switched over according to being actually needed.Because air chamber 41 need not install the speculum or speculum group for multiple reflections light, make
Obtain gas absorption cell 1 simple in construction, dismounting easy to install and repeatedly installing/dismounting can't influence accuracy of detection, it is this without reflection
The simple structure of mirror or speculum group enhances the shock resistance and environmental suitability of gas absorption cell 1, while through type, short light path
Air chamber structure design cause absorption cell 1 the volume of air chamber 41 it is small, correspondingly reduce the volume of gas absorption cell 1.Preferably,
Gas absorption cell 1 can reach very high accuracy of detection, such as the solution gas in transformer oil under the conditions of small volume, short light path
Application in physical examination survey, better than minimum detection limit as defined in national grid company standard.This succinct structure also causes gas
The repair and maintenance of absorption cell 1 is more convenient.
In gas absorption cell 1 of the present utility model, keep between fiber optic collimator module 2 and cavity 4, cavity 4 is with focusing on mould
Being tightly fastened between block 3 is most important.For example the both ends of cavity 4 can be consolidated with fiber optic collimator module respectively by nested mode
Fixed end 23 and focus module fixing end 33 is closed is fixed together.In a preferred embodiment, when cavity 4 is inwall light
During sliding cylinder, the front end of cavity 4 is provided with screwed hole and toroidal cavity, with fiber optic collimator module fixing end 23 and first support 24
Close connection；The rear end of cavity 4 also is provided with screwed hole and toroidal cavity, close with focus module fixing end 33 and second support 34
Connection.Meanwhile the junction of the rear and front end of cavity 4 can by fluid sealant and/or raw material band, add bolt 44 if necessary and distinguish
Fixed with fiber optic collimator module fixing end 23 and/or focus module fixing end 33, this sealing structure can fully ensure air chamber
41 air-tightness, also make it that the repair and maintenance of gas absorption cell 1 is more convenient.
In a preferred embodiment, above-mentioned accurate light modulation structure 22 can utilize the stability principle of triangle, adopt
With double triangle nested structure, the fine adjustment of light path is realized so that optical path adjusting is simple, Stability Analysis of Structures and shock resistance are good.
In one embodiment, helicitic texture and chamber can be respectively equipped with above-mentioned first support 24 and second support 34
The both ends of body 4 form threaded connection, for being fixedly connected with cavity 4.
Preferably, screwed hole can be respectively equipped with first support 24 and second support 34, be screwed company with workbench
Connect, ensure the shock resistance of absorption cell 1.
The above-mentioned rear portion of focus module 3 can further connect photoelectric detection module (not shown), and the photoelectric detection module is used for
Receive the light being emitted from light-emitting window 32 and be converted to electric signal.
Above-mentioned gas absorption cell 1 can be applied to detection gas.For example it can be used for detecting Gases Dissolved in Transformer Oil.
Gas in Oil of Transformer component and concentration largely reflected the thermoelectricity fault degree of transformer and using the longevity
Life, Gas in Oil of Transformer, which analyzes oneself, turns into the effective technology means of inside transformer Hidden fault detection.Research and development
Multicomponent gas, online measuring technique in transformer oil have important theory and realistic meaning.Solution gas in transformer oil
Body component mainly has N2、O2、H2、CH4、C2H2、C2H4、C2H6、CO、CO2Deng gas.Under normal circumstances in oil-immersed power transformer
Oil and insulation paper material under heat and the collective effect of electricity, can gradual aging and decomposition, produce a small amount of low molecular hydrocarbon and
CO2, the gas such as CO.If inside transformer occur Superheated steam drier, discharging fault or make moist situation when, the yield of these gases
It can increase sharply.Therefore the operation conditions of transformer can be reflected by monitoring Gas in Oil of Transformer species and content on-line,
Timely and accurately detect power transformer Hidden fault.
It is found through experiments that, gas absorption cell 1 of the present utility model is used for by the laser of infrared light and/or near infrared light
Detect Gases Dissolved in Transformer Oil component such as N2、O2、H2、CH4、C2H2、C2H4、C2H6、CO、CO2Deng gas when, have it is high
Detection sensitivity and reliability, such as gas absorption cell 1 for above-mentioned gas Monitoring lower-cut less than State Grid Corporation of China look forward to
Lowest detection limit value as defined in industry standard, therefore on-line checking can be effectively realized, reduce the rate of false alarm of transformer fault.
It should be noted that term " comprising " herein, "comprising" or its any other variant are intended to non-row
His property includes, so that process, method, article or equipment including a series of elements not only include those key elements, and
And also include the other element being not expressly set out, or also include for this process, method, article or equipment institute inherently
Key element.
Above example is only to illustrate the technical scheme of the utility model patent, rather than its limitations；Although with reference to before
Embodiment is stated the utility model patent is described in detail, it will be understood by those within the art that：It is still
Technical scheme described in foregoing embodiments can be modified, or which part technical characteristic is equally replaced
Change；And these modifications or replacement, the essence of appropriate technical solution is departed from each embodiment technology of the utility model patent
The spirit and scope of scheme.
Claims (10)
1. a kind of absorption cell for gas detection, including：For the fiber optic collimator module for being collimated the light of light source, it is used for
The focus module for being focused and making focusing light to be emitted after collimation by the light of cavity air chamber, positioned at fiber optic collimator module and
Cavity between focus module, for introducing and discharging under test gas, wherein,
The fiber optic collimator module includes optical fiber collimator, the accurate light modulation structure for adjusting light path, for precision to be dimmed
Structure and the closed fiber optic collimator module fixing end being fixed together in cavity one end, the collimation lens end of wherein optical fiber collimator is inserted
Enter in the central through hole of accurate light modulation structure and fixed；
Include condenser lens in the focus module, for fixed focus lenses and with the cavity other end is closed is fixed together
Focus module fixing end, the optical axis of the condenser lens and the central axis of cavity air chamber, the optical axis coincidence of fiber optic collimator module；
The both ends of the cavity respectively with fiber optic collimator module fixing end and focus module fixing end airtight connection, cavity it is hollow
Part is air chamber for accommodating under test gas, and the light beam after collimation is transferred to focus module by air chamber, its side be provided with into
Gas port and gas outlet, and be used at least one sensor be installed for detecting the temperature and pressure of air chamber ginseng provided with connecting hole
Number.
2. absorption cell as claimed in claim 1, it is characterised in that the fiber optic collimator module also includes fiber optic collimator module and protected
Protective case, for covering optical fiber collimator, accurate light modulation structure, fiber optic collimator module fixing end, these parts are protected not by the external world
The influence of environment and object.
3. absorption cell as claimed in claim 2, it is characterised in that also include being used to fix the fiber optic collimator module protection shell
Second support with the first support of the cavity front end and for fixing the cavity rear end, the first support and second
Support is fixed together, supports whole absorption cell.
4. absorption cell as claimed in claim 1 or 2, it is characterised in that also include being used for the light inlet for accessing light source.
5. absorption cell as claimed in claim 4, it is characterised in that the light inlet is located in first support.
6. absorption cell as claimed in claim 1 or 2, it is characterised in that light-emitting window is provided with the focus module fixing end,
That is the exit portal of condenser lens, the optical axis of condenser lens and the central axis of cavity air chamber, the optical axis coincidence of fiber optic collimator module.
7. absorption cell as claimed in claim 1 or 2, it is characterised in that there is center to lead in the fiber optic collimator module fixing end
Hole, oblique window is fixed with the central through hole, for reducing optical standard tool interference.
8. absorption cell as claimed in claim 6, it is characterised in that the focus module fixing end further connects photodetection
Module, the photoelectric detection module are used for the light received from light-emitting window outgoing and are converted to electric signal.
9. absorption cell as claimed in claim 1 or 2, it is characterised in that the detection for Gases Dissolved in Transformer Oil.
10. absorption cell as claimed in claim 9, it is characterised in that the gas is selected from N2、O2、H2、CH4、C2H2、C2H4、
C2H6、CO、CO2One or both of more than.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720864607.3U CN207147951U (en) | 2017-07-17 | 2017-07-17 | A kind of absorption cell for gas detection |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720864607.3U CN207147951U (en) | 2017-07-17 | 2017-07-17 | A kind of absorption cell for gas detection |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN207147951U true CN207147951U (en) | 2018-03-27 |
Family
ID=61675594
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201720864607.3U Active CN207147951U (en) | 2017-07-17 | 2017-07-17 | A kind of absorption cell for gas detection |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN207147951U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107167428A (en) * | 2017-07-17 | 2017-09-15 | 上海禾楷电气科技有限公司 | A kind of absorption cell detected for gas |
| CN109596560A (en) * | 2018-12-19 | 2019-04-09 | 电子科技大学 | A kind of integrated infrared gas sensor of multichannel |
-
2017
- 2017-07-17 CN CN201720864607.3U patent/CN207147951U/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107167428A (en) * | 2017-07-17 | 2017-09-15 | 上海禾楷电气科技有限公司 | A kind of absorption cell detected for gas |
| CN107167428B (en) * | 2017-07-17 | 2023-04-25 | 上海禾楷电气科技有限公司 | Absorption tank for gas detection |
| CN109596560A (en) * | 2018-12-19 | 2019-04-09 | 电子科技大学 | A kind of integrated infrared gas sensor of multichannel |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107167428A (en) | A kind of absorption cell detected for gas | |
| CN105424631B (en) | A kind of hypersensitivity nitrogen oxides measuring system based on UV, visible light wave band absorption spectrum | |
| CN106153573B (en) | A kind of high temperature and pressure optics cavity and its application method for absorption coefficient calibration | |
| KR100984020B1 (en) | An apparatus for detecting the leakage of heavy water in a nuclear reactor system and the detection method | |
| CN108931504A (en) | A kind of annular multiple spot reflection type photoelectricity gas sensor probe | |
| CN102749286B (en) | Novel portable gas normal position monitor of flue gas and pipeline gas | |
| CN104483282B (en) | Self-calibration gas chamber and optical fiber gas sensor detection system | |
| CN109444074B (en) | Laser spectrum absorption probe device with self-calibration function and measurement method thereof | |
| CN103411920A (en) | Portable multi-component online monitor of gas dissolved in transformer oil | |
| CN207147951U (en) | A kind of absorption cell for gas detection | |
| CN105067546A (en) | High-temperature multispectral coupling optical-mechanical system | |
| CN104483284A (en) | Optical system and detection device for flue gas monitor | |
| CN104266971A (en) | In-situ calibration device and method for online detection of pipeline gas | |
| CN204439539U (en) | A kind of optical system of flue gas monitoring instrument and pick-up unit | |
| CN204346907U (en) | A kind of self calibration air chamber and fiber gas sensor detection system | |
| CN206420761U (en) | A kind of high performance gas absorption cell | |
| CN205958454U (en) | Dangerous gas monitoring device that leaks of reflective infrared laser industry of self -adaptation | |
| CN208206775U (en) | A kind of gas absorption cell | |
| CN216350326U (en) | Multi-gas non-spectroscopic infrared gas sensor with four-petal cavity | |
| CN101149351A (en) | Fixed element light splitter for co-shaping x-ray fluorescence spectrometer | |
| CN108827906A (en) | A kind of near infrared spectrum multicomponent gas on-line detecting system and method | |
| CN110736720A (en) | online detector for detecting HF gas content and detection method | |
| JPS6279331A (en) | Method and apparatus for measuring concentration of hydrogen peroxide | |
| CN110031405A (en) | Non-fiber, light path adjustable laser pipeline gas sensor in a kind of detection bar | |
| CN104316462A (en) | M-shaped long-optical path gas chamber |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |