CN203287310U - Double-cavity methane gas concentration detection device - Google Patents
Double-cavity methane gas concentration detection device Download PDFInfo
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- CN203287310U CN203287310U CN201320373830XU CN201320373830U CN203287310U CN 203287310 U CN203287310 U CN 203287310U CN 201320373830X U CN201320373830X U CN 201320373830XU CN 201320373830 U CN201320373830 U CN 201320373830U CN 203287310 U CN203287310 U CN 203287310U
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Abstract
The utility model discloses a double-cavity methane gas concentration detection device, and belongs to the field of gas concentration detection. The double-cavity methane gas concentration detection device aims to solve the problems that an existing gas concentration detection device is poor in stability and repeatability and is high in cost. A connecting blocking board divides high diffuse reflection double cavities into an incident cavity and an outgoing cavity, a double-cavity communication hole is formed in the connecting blocking board, a first wedge-shaped quartz lens and a second wedge-shaped quartz lens are arranged in an incident hole and an outgoing hole, an tunable multimode diode laser and a detector are arranged corresponding to the wedge-shaped quartz lenses, a sine wave signal generator and a sawtooth wave signal generator are arranged side by side and are respectively connected with a coupler, the coupler is connected with a laser current controller, the laser current controller is connected with the tunable multimode diode laser, the detector, the sine wave signal generator and the sawtooth wave signal signal generator are all connected with a data collecting card, and the data collecting card is connected with an embedded type microcomputer system. The double-cavity methane gas concentration detection device is used for detecting the concentration of methane gas.
Description
Technical field
The utility model relates to a kind of concentration of methane gas pick-up unit, is specifically related to a kind of two-chamber concentration of methane gas pick-up unit, belongs to the gas concentration detection field.
Background technology
The gas concentration real time on-line monitoring all has very important significance in commercial production, biological medicine and environmental monitoring field.Methane is the main chemical composition material of rock gas, its volumetric concentration〉run into naked light 4.9% the time or static can produce blast, therefore the Sensitive Detection to low-concentration methane is most important to the security of raising work and life in colliery and family.
Tunable diode laser absorption spectroscopy technology (Tunable diode laser absorption spectroscopy-TDLAS) but advantage with highly sensitive, high-resolution, high-speed real time on-line monitoring makes it become the main stream approach of present optical gas monitoring.Can improve the detection sensitivity of methane with the TDLAS technology, increase light path and can further improve detection sensitivity on the basis of TDLAS, reduce the detection limit of methane.Many logical ponds have the ability of very strong prolongation light path, it is also present the most frequently used optical path lengthening method, but how logical pond has certain requirement could realize that light path extends preferably to incident angle, and the small variation of incident angle all can cause very large light path to change, so stability and repeatability are poor, and its inner accurate optical device causes Duo Tongchi to have higher price, and then improves the cost of whole sniffer.
The utility model content
The utility model is in order to solve existing gas concentration measuring apparatus stability and repeatability is poor, the problem that cost is high, and then a kind of two-chamber concentration of methane gas pick-up unit is provided.
The utility model in order to solve the problems of the technologies described above the technical scheme of taking is:
The described two-chamber concentration of methane gas of utility model pick-up unit comprises high diffuse reflection two-chamber, connects baffle plate, air intake opening, exhausr port, the first wedge shape fused silica glass, the second wedge shape fused silica glass, sine wave signal generator, Saw-tooth Signal Waveform Generator, coupling mechanism, embedded pc system, laser current controller, tunable multimode diode laser, detector and data collecting card;
the top of described high diffuse reflection two-chamber is provided with air intake opening, the below of high diffuse reflection two-chamber is provided with exhausr port, described connection baffle plate is arranged in high diffuse reflection two-chamber, and high diffuse reflection two-chamber is divided into incident chamber and outgoing chamber, connect on baffle plate and have the two-chamber intercommunicating pore, described incident has into perforation on chamber, outgoing has perforation hole on chamber, the first wedge shape fused silica glass is arranged in perforation, the second wedge shape fused silica glass is arranged in perforation hole, tunable multimode diode laser and the first corresponding setting of wedge shape fused silica glass, detector and the second corresponding setting of wedge shape fused silica glass, sine wave signal generator is connected with Saw-tooth Signal Waveform Generator and is connected with coupling mechanism respectively, coupling mechanism is connected with the laser current controller, the laser current controller is connected with tunable multimode diode laser, the scanning sawtooth wave that the sine wave that sine wave signal generator produces and Saw-tooth Signal Waveform Generator produce is coupled and is loaded on the laser current controller by coupling mechanism, the laser current controller is used for controlling the working current of tunable multimode diode laser,
the modulation output light of tunable multimode diode laser enters into high diffuse reflection two-chamber through the first wedge shape fused silica glass, modulation output light is received by detector after the second wedge shape fused silica glass, detector, sine wave signal generator and Saw-tooth Signal Waveform Generator all are connected with data collecting card, data collecting card is connected with embedded pc system, detector converts after electric signal light signal by the data collecting card collection to, the trigger pip of Saw-tooth Signal Waveform Generator, and the modulation signal of sine wave signal generator is input in data collecting card together, the signal that data collecting card will collect is sent into embedded pc system and is carried out analyzing and processing.
Preferably: described detector is photodetector.
Preferably: described embedded pc system is connected to form by microprocessor and light-emitting diode display.
Preferably: described tunable multimode diode laser is 1.3 μ m tunable diode lasers.
Preferably: the two-chamber intercommunicating pore on described connection baffle plate accounts for and connects 1/22nd of baffle plate area.
Preferably: evenly scribble and have from seeing the high-reflecting film of near-infrared band on described high diffuse reflection two-chamber inwall.
The utility model compared with prior art has following effect: two-chamber concentration of methane gas pick-up unit of the present utility model is a kind of quick, sensitive on-Line Monitor Device.Inheriting on the high-sensitive advantage of TDLAS technology basis, utilizing high diffuse reflection double cavity structure to increase light path, further improving detection sensitivity.Simultaneously, high diffuse reflection double cavity structure takes full advantage of space, be convenient to the miniaturization of instrument, the experiment structure shows, use high diffuse reflection double cavity structure to be greatly improved in measurement sensitivity than the cube single cavity structure with volume, and two-chamber concentration of methane gas pick-up unit stability of the present utility model and good reproducibility, cost is low.
Description of drawings
Fig. 1 is the structural representation of two-chamber concentration of methane gas pick-up unit described in the utility model.
In figure:
The high diffuse reflection two-chamber of 1-, 2-connect baffle plate, 3-air intake opening, 4-exhausr port, 5-the first wedge shape fused silica glass, 6-the second wedge shape fused silica glass, 7-sine wave signal generator, 8-Saw-tooth Signal Waveform Generator, 9-coupling mechanism, 10-embedded pc system, 11-laser current controller, 12-is tunable multimode diode laser, 13-detector, 14-data collecting card.
Embodiment
Below elaborate with reference to the accompanying drawings the utility model preferred embodiment.
As shown in Figure 1, two-chamber concentration of methane gas pick-up unit described in the utility model comprises high diffuse reflection two-chamber 1, connects baffle plate 2, air intake opening 3, exhausr port 4, the first wedge shape fused silica glass 5, the second wedge shape fused silica glass 6, sine wave signal generator 7, Saw-tooth Signal Waveform Generator 8, coupling mechanism 9, embedded pc system 10, laser current controller 11, tunable multimode diode laser 12, detector 13 and data collecting card 14;
the top of described high diffuse reflection two-chamber 1 is provided with air intake opening 3, the below of high diffuse reflection two-chamber 1 is provided with exhausr port 4, described connection baffle plate 2 is arranged in high diffuse reflection two-chamber 1, and high diffuse reflection two-chamber 1 is divided into incident chamber 1-1 and outgoing chamber 1-2, connect on baffle plate 2 and have the two-chamber intercommunicating pore, have into perforation on described incident chamber 1-1, have perforation hole on the 1-2 of outgoing chamber, the first wedge shape fused silica glass 5 is arranged in perforation, the second wedge shape fused silica glass 6 is arranged in perforation hole, tunable multimode diode laser 12 and the first corresponding setting of wedge shape fused silica glass 5, detector 13 and the second corresponding setting of wedge shape fused silica glass 6, sine wave signal generator 7 is connected with Saw-tooth Signal Waveform Generator and is set up in parallel and is connected with coupling mechanism 9 respectively, coupling mechanism 9 is connected with laser current controller 11, laser current controller 11 is connected with tunable multimode diode laser 12, the scanning sawtooth wave that the sine wave that sine wave signal generator 7 produces and Saw-tooth Signal Waveform Generator 8 produce is loaded on laser current controller 11 by coupling mechanism 9 couplings, laser current controller 11 is used for controlling the working current of tunable multimode diode laser 12,
the modulation output light of tunable multimode diode laser 12 enters into high diffuse reflection two-chamber 1 through the first wedge shape fused silica glass 5, modulation output light is received by detector 13 after the second wedge shape fused silica glass 6, detector 13, sine wave signal generator 7 is connected with Saw-tooth Signal Waveform Generator and all with data collecting card 14, is connected, data collecting card 14 is connected with embedded pc system 10, detector 13 is gathered by data collecting card 14 after converting light signal to electric signal, the trigger pip of Saw-tooth Signal Waveform Generator 8, and the modulation signal of sine wave signal generator 7 is input in data collecting card 14 together, the signal that data collecting card 14 will collect is sent into embedded pc system 10 and is carried out analyzing and processing.
Described detector 13 is photodetector.
Described embedded pc system 10 is connected to form by microprocessor and light-emitting diode display.
Described tunable multimode diode laser 12 is 1.3 μ m tunable diode lasers.
Two-chamber intercommunicating pore on described connection baffle plate 2 accounts for and connects 1/22nd of baffle plate 2 areas.
Evenly scribble and have from seeing the high-reflecting film of near-infrared band on described high diffuse reflection two-chamber 1 inwall.
In present embodiment, the first wedge shape fused silica glass 5 and the second wedge shape fused silica glass 6 are used for being encapsulated into perforation and perforation hole on the one hand; Prevent on the other hand laser because eyeglass produces interference fringe, if fused silica glass is the eyeglass of equal thickness, owing to interfering the striped that produces will affect greatly second harmonic signal shape and intensity, so wedge-shaped lens can effectively reduce interference fringe.
In present embodiment, sine wave signal generator 7 produces modulated sinusoid that frequencies are f1 and Saw-tooth Signal Waveform Generator 8 to produce frequencies is that the scanning sawtooth wave of f2 is loaded on the Injection Current of tunable multimode diode laser 12 by coupling mechanism 9 couplings, realizes the modulation to Output of laser; Laser current controller 11 can be controlled the working current of tunable multimode diode laser 12.the modulation Output of laser of described tunable multimode diode laser 12 enters in the incident chamber 1-1 that methane gas to be measured is housed through the first wedge shape fused silica glass 5, modulated laser interacts with tested methane gas in the 1-1 of incident chamber, simultaneously, entered in the 1-2 of outgoing chamber by the two-chamber intercommunicating pore that connects on baffle plate 2, and with the methane gas in the 1-2 of outgoing chamber, continue to interact, penetrated by perforation hole finally, and by detector 13, received, detector 13 is gathered by data collecting card 14 after converting light signal to electric signal, the trigger pip of Saw-tooth Signal Waveform Generator 8, and the modulation signal of sine wave signal generator 7 is input in data collecting card 14 together, the electric signal that data collecting card 14 will collect is sent into embedded pc system 10 and is carried out analyzing and processing, obtain finally tested concentration of methane gas.
The utility model uses the Wavelength modulation spectroscopy technology, will be loaded in the Injection Current of tunable multimode diode laser after the coupling of the scanning sawtooth signal of the modulated sinusoid signal of a upper frequency and a low frequency.The modulating frequency f1 of the sinusoidal signal that described sine wave signal generator 7 produces is 1,000 times of the saw wave modulator frequency f 2 that produces of Saw-tooth Signal Waveform Generator 8, if the sawtooth wave frequency that Saw-tooth Signal Waveform Generator 8 produces is 10Hz, the sine wave modulation frequency of sine wave signal generator 7 generations is 10kHz.Laser is by high diffuse reflection two-chamber 1, and with the methane gas in high diffuse reflection two-chamber 1, interact, and by detector, received, by detector, light signal is changed into electric signal finally and gathered by data card, finally sent embedded pc system to carry out data analysis and processed, provided finally concentration information.The expression formula of gas concentration to be measured can be expressed as: N=1.95k Δ A/ α MD, in formula, N is gas concentration to be measured in integrating sphere, k is harmonic signal and direct absorption signal scale-up factor, Δ A harmonic signal peak value, α is the absorption cross section of gas to be measured, M is the reflection coefficient of integrating sphere, and D is the diameter of high diffuse reflection two-chamber 1.Present embodiment, just to the exemplary illustration of this patent, does not limit its protection domain, and those skilled in the art can also change its part, as long as no the Spirit Essence that exceeds this patent, all in the protection domain of this patent.
Claims (5)
1. two-chamber concentration of methane gas pick-up unit, it comprises high diffuse reflection two-chamber (1), connects baffle plate (2), air intake opening (3), exhausr port (4), the first wedge shape fused silica glass (5), the second wedge shape fused silica glass (6), sine wave signal generator (7), Saw-tooth Signal Waveform Generator (8), coupling mechanism (9), embedded pc system (10), laser current controller (11), tunable multimode diode laser (12), detector (13) and data collecting card (14);
it is characterized in that: the top of described high diffuse reflection two-chamber (1) is provided with air intake opening (3), the below of high diffuse reflection two-chamber (1) is provided with exhausr port (4), described connection baffle plate (2) is arranged in high diffuse reflection two-chamber (1), and high diffuse reflection two-chamber (1) is divided into incident chamber (1-1) and outgoing chamber (1-2), connect on baffle plate (2) and have the two-chamber intercommunicating pore, have into perforation on described incident chamber (1-1), have perforation hole on outgoing chamber (1-2), the first wedge shape fused silica glass (5) is arranged in perforation, the second wedge shape fused silica glass (6) is arranged in perforation hole, tunable multimode diode laser (12) and the first corresponding setting of wedge shape fused silica glass (5), detector (13) and the second corresponding setting of wedge shape fused silica glass (6), sine wave signal generator (7) is connected 8 with Saw-tooth Signal Waveform Generator) be set up in parallel and be connected with coupling mechanism (9) respectively, coupling mechanism (9) is connected with laser current controller (11), laser current controller (11) is connected with tunable multimode diode laser (12), the scanning sawtooth wave that the sine wave that sine wave signal generator (7) produces and Saw-tooth Signal Waveform Generator (8) produce is loaded on laser current controller (11) by coupling mechanism (9) coupling, laser current controller (11) is used for controlling the working current of tunable multimode diode laser (12),
the modulation output light of tunable multimode diode laser (12) enters into high diffuse reflection two-chamber (1) through the first wedge shape fused silica glass (5), modulation output light is received by detector (13) after the second wedge shape fused silica glass (6), detector (13), sine wave signal generator (7) is connected 8 with Saw-tooth Signal Waveform Generator) all with data collecting card (14), be connected, data collecting card (14) is connected with embedded pc system (10), detector (13) is gathered by data collecting card (14) after converting light signal to electric signal, the trigger pip of Saw-tooth Signal Waveform Generator (8), and the modulation signal of sine wave signal generator (7) is input in data collecting card (14) together, the signal that data collecting card (14) will collect is sent into embedded pc system (10) and is carried out analyzing and processing.
2. two-chamber concentration of methane gas pick-up unit according to claim 1, it is characterized in that: described detector (13) is photodetector.
3. two-chamber concentration of methane gas pick-up unit according to claim 2, it is characterized in that: described embedded pc system (10) is connected to form by microprocessor and light-emitting diode display.
4. two-chamber concentration of methane gas pick-up unit according to claim 3, it is characterized in that: described tunable multimode diode laser (12) is 1.3 μ m tunable diode lasers.
5. according to claim 1,2,3 or 4 described two-chamber concentration of methane gas pick-up units, it is characterized in that: the two-chamber intercommunicating pore on described connection baffle plate (2) accounts for and connects 1/22nd of baffle plate (2) area.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN201320373830XU CN203287310U (en) | 2013-06-27 | 2013-06-27 | Double-cavity methane gas concentration detection device |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201320373830XU CN203287310U (en) | 2013-06-27 | 2013-06-27 | Double-cavity methane gas concentration detection device |
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| CN203287310U true CN203287310U (en) | 2013-11-13 |
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| CN201320373830XU Expired - Fee Related CN203287310U (en) | 2013-06-27 | 2013-06-27 | Double-cavity methane gas concentration detection device |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105300889A (en) * | 2015-11-10 | 2016-02-03 | 哈尔滨工业大学 | Method and device for measuring trace gas concentration with diffuse reflection integral cavity as photoacoustic cell |
-
2013
- 2013-06-27 CN CN201320373830XU patent/CN203287310U/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105300889A (en) * | 2015-11-10 | 2016-02-03 | 哈尔滨工业大学 | Method and device for measuring trace gas concentration with diffuse reflection integral cavity as photoacoustic cell |
| CN105300889B (en) * | 2015-11-10 | 2018-09-11 | 哈尔滨工业大学 | The method and device of trace gas concentration is measured as photoacoustic cell using diffusing reflection integral chamber |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20131113 Termination date: 20140627 |
|
| EXPY | Termination of patent right or utility model |