CN203720078U - Double wavelength difference methane concentration sensor - Google Patents
Double wavelength difference methane concentration sensor Download PDFInfo
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- CN203720078U CN203720078U CN201320656317.1U CN201320656317U CN203720078U CN 203720078 U CN203720078 U CN 203720078U CN 201320656317 U CN201320656317 U CN 201320656317U CN 203720078 U CN203720078 U CN 203720078U
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- light
- signal
- wavelength
- processing module
- air chamber
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- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 title claims abstract description 63
- 230000003287 optical effect Effects 0.000 claims abstract description 49
- 238000001914 filtration Methods 0.000 claims abstract description 16
- 238000004458 analytical method Methods 0.000 claims abstract description 11
- 230000003321 amplification Effects 0.000 claims description 4
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 4
- 239000004065 semiconductor Substances 0.000 claims description 3
- 239000007789 gas Substances 0.000 abstract description 15
- 238000000034 method Methods 0.000 description 18
- 238000010521 absorption reaction Methods 0.000 description 5
- 238000001514 detection method Methods 0.000 description 5
- 238000005259 measurement Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- 238000006555 catalytic reaction Methods 0.000 description 3
- 238000002329 infrared spectrum Methods 0.000 description 3
- 238000005305 interferometry Methods 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- 239000006096 absorbing agent Substances 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 239000003245 coal Substances 0.000 description 1
- 230000019771 cognition Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000002360 explosive Substances 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 231100000572 poisoning Toxicity 0.000 description 1
- 230000000607 poisoning effect Effects 0.000 description 1
- 239000011435 rock Substances 0.000 description 1
- 241000894007 species Species 0.000 description 1
Abstract
The utility model relates to a double wavelength difference methane concentration sensor which comprises a light source, an optical processing module, a signal processing module and a signal analysis module, wherein the light source is used for transmitting an optical signal; the optical processing module comprises a photoelectric detector and is used for filtering the optical signal emitted by the light source so as to enable a group of optical signals with the first wavelength and a group of optical signals with the second wavelength to pass through, and to enable the two groups of optical signals periodically and respectively to be transmitted to the photoelectric detector by means of gases to be detected, and the photoelectric detector converts the optical signals into electric signals; the signal processing module is used for filtering and amplifying the electric signals output by the optical processing module; and the signal analysis module is used for analyzing the electric signals output by the signal processing module.
Description
Technical field
The application belongs to safety in production field, is specifically related to a kind of dual-wavelength difference sensing methane concentration device that detects principle based on infrared differential.
Background technology
Methane is a kind of flammable explosive gas, is the principal ingredient of the multiple gases such as mine gas and rock gas fuel.It is extensively present in geology coal seam, is the first factor that threatens mine safety.Therefore, study a kind of detection method, detect real-time and accurately methane concentration, significant to mine safety operation.
Up to the present, the method for detection concentration of methane gas has a variety of, and the detection method of domestic use mainly contains: catalysis element method, radiant heat method, optical interferometry and infrared spectrum absorption process.
Catalysis element method is to utilize Huygens's electric bridge, and methane changes the resistance of catalysis original paper by heating under catalytic specie effect, measures methane concentration thereby changed bridge balance.This method exists that shelf life is short, measurement range is little, easily poisoning and poor these shortcomings of degree of stability.
Thermal conduction principle is the different methane concentrations of measuring of thermal conductivity that utilize air and methane.The shortcoming of this method is that it is different from all sensitivities of gas of air to temperature conductivity, and in the time detecting methane, some background gas cognition is brought certain error.
Optical interferometry is that the concentration of the refractive index that should use up and methane in measurement gas is about detecting the concentration of methane gas.The drawback of this method is poor selectivity, is subject to temperature variation and barometric pressure effect can bring error, is easily subject in addition the impact of other gases etc.
Infrared spectrum absorption process is a kind of new method growing up in recent years, and it is the product being developed by spectral analysis technique.Utilize the firedamp sensor that this principle is developed can overcome the intrinsic defect of active service sensor, the technical goals such as realization response is fast, the life-span is long, adjustment cycle length, this device has been widely used in the middle of methane concentration detection at present.Dual-wavelength difference method is the one of infrared spectrum absorption process, traditional dual-wavelength difference method is owing to having used two photodetectors, will inevitably there is error in its testing result, also can there is the problem of the gentle chamber interior walls scattering of foreign particle scattering in its common air chamber adopting, cause the inaccurate of testing result.
Utility model content
For the above-mentioned deficiency of prior art, the application has proposed a kind of dual-wavelength difference sensing methane concentration device, and technical scheme is as follows:
Comprise light source, light processing module, signal processing module and signal analyse block;
Wherein
Described light source is used for sending light signal;
Described smooth processing module comprises an optical filtering module, a photodetector, a rotation lighting machine and an air chamber;
Described optical filtering module, for filtering the light signal that light source sends, passes through the light signal of one group of first wavelength and the light signal of one group of second wave length;
In described air chamber, circulation has gas to be measured;
Described rotation lighting machine periodically makes above-mentioned two groups of light signals be sent to described photodetector through described air chamber respectively;
Light signal is converted to electric signal by described photodetector;
Described signal processing module is for carrying out filtering and amplification to the electric signal of described smooth processing module output;
Described signal analyse block is for analyzing the electric signal of described signal processing module output.
Further,
Described light source is LED or semiconductor laser.
Further,
Described optical filtering module comprises convex lens, right cylinder light chamber, upper optical filter, lower optical filter;
Described convex lens are converted to parallel optical signal for the light signal that light source is sent;
Described upper optical filter and lower optical filter are arranged at the light path midsection of described right cylinder light chamber;
Described upper optical filter can be the light signal of the first wavelength by centre wavelength;
The light signal that described lower optical filter can be second wave length by centre wavelength;
Described rotation lighting machine is arranged at the end of described right cylinder light chamber;
Described rotation lighting machine, air chamber rotate together with photodetector.
Further,
The filter factor of described upper optical filter and lower optical filter equates.
Further,
Adopt stepper motor to drive described rotation lighting machine, air chamber and photodetector rotation;
Described rotation lighting machine comprises a logical light window;
The every rotation one of described rotation lighting machine is enclosed, and described logical light window has upper and lower two stop positions;
When stop position above stopping at, the light signal of described the first wavelength passes from described logical light window;
In the time of stop position below stopping at, the light signal of described second wave length passes from described logical light window.
Further,
The entrance of described air chamber, outlet are prism wedge;
Described air chamber rear and front end is two plane mirrors;
The two ends up and down of described air chamber are dustproof network structure.
Further,
Described photodetector is photoelectron emissions detector or photoconductive detector or photovoltaic detector.
Further,
Described the first wavelength is 1.650 μ m;
Described second wave length is 1.620 μ m.
The dual-wavelength difference sensing methane concentration device that the application proposes, by the improvement of structure, has eliminated the problem that error that different detector property differences bring and air chamber scattering bring, and has further improved the precision detecting.
Brief description of the drawings
Fig. 1 is the basic structure of the application's dual-wavelength difference sensing methane concentration device.
Fig. 2 is the structural representation of light processing module,
Wherein, Reference numeral is followed successively by: convex lens 201, right cylinder light chamber 202, upper optical filter 203, lower optical filter 204, rotation lighting machine 205, air chamber 206, photodetector 207.
Fig. 3 is signal processing module filtering and amplifying circuit schematic diagram.
Embodiment
The dual-wavelength difference sensing methane concentration device that the application proposes is mainly by light source, light processing module, and signal processing module, signal analyse block four parts compositions, as shown in Figure 1.
Wherein, light source is used for sending light signal;
Light processing module is used for light signal to process, and light signal is converted to electric signal;
Signal processing module is for processing electric signal;
Thereby signal analyse block is for obtaining the concentration of methane to electric signal analysis.
Light source can be selected LED or semiconductor laser LD.
Fig. 2 is the structural representation of light processing module, and this is the nucleus module of whole sensor, is made up of convex lens 201, right cylinder light chamber 202, upper optical filter 203, lower optical filter 204, rotation lighting machine 205, air chamber 206 and photodetector 207.
The process that light processing module is processed light is as follows: the light being sent by light source is converted to directional light after convex lens 201, directional light is through right cylinder light chamber 202, in the middle of the light path of right cylinder light chamber 202, be provided with two optical filters 203,204 along cross section, upper optical filter 203 can be λ by centre wavelength
1(1.650 μ light m), lower optical filter can be λ by centre wavelength
2(1.620 μ light m), the filter factor of two optical filters is equal, and the light of above-mentioned two kinds of wavelength can continue transmission along light path through optical filter, and except two optical filters, the other parts in cross section are light tight.Light is divided into two after upper and lower optical filter, and residue centre wavelength is λ
1(1.650 μ m) and λ
2(1.620 μ, two groups of light m).
Be provided with a rotation lighting machine 205 at the end of right cylinder light chamber 202, driven by stepper motor, stepper motor driven rotary lighting machine 205, air chamber 206 rotate together with photodetector 207.Rotation lighting machine 205 comprises a logical light window, and rotation lighting machine 205 every rotation one is enclosed, and logical light window has upper and lower two stop positions, and when stop position above stopping at, wavelength is λ
1light pass from logical light window, in the time of stop position below stopping at, wavelength is λ
2light pass from logical light window, this rotation lighting machine 205 is for being sent to air chamber 206 by the different light of above-mentioned two groups of wavelength in the different time periods, detected by same photodetector 207, thereby eliminate the error of bringing to measurement result due to the characteristic difference of photodetector individuality.
Gas to be measured in air chamber 206 produces absorption to light.Light is sent to after air chamber 206, and the entrance of air chamber 206 is prism wedge, is conducive to adjust the incident angle of light.Air chamber rear and front end is two plane mirrors, by adjusting the incident angle of light, utilizes catoptron to make light path process multiple reflections in air chamber, can increase light path, and then can effectively improve the sensitivity of detection.Broken line in Fig. 2 air chamber 206 shows light path.The two ends up and down of air chamber 206 are dustproof network structure, have both been conducive to the circulation of air, can avoid again the error that in air, dust brings measurement result.The outlet of air chamber 206 is also prism wedge.Finally, light penetrates to photodetector 207 from outlet prism, utilizes photodetector 207 that light signal is converted to electric signal.
Photodetector 207 can adopt photoelectron emissions detector, photoconductive detector or photovoltaic detector.
The electric signal that signal processing module is exported photodetector 207 carries out filtering, amplifies and process, signal processing module can adopt various filtering and amplification module, Fig. 3 only shows a kind of the application's of being applicable to wave filter and amplifier architecture, signal (electric signal), from left end input, is exported after filtering, amplification.
Finally, signal processing module exports electric signal to signal analyse block, the electric signal K being measured by signal analyse block basis, and default rule is analyzed methane concentration.
Photodetector 207 receives two groups of light signal V in a swing circle
1, V
2,
Stray light signal V
3=D+B (t),
Wherein, I (λ
1), I (λ
2) be the light intensity of the two-beam after optical filter filters, I
0(λ
1), I
0(λ
2) be the initial light intensity of two wavelength, K is measurement electric signal,
for gas to be measured is for the absorption coefficient function of two kinds of wavelength, β (λ
1), β (λ
2) representing light path disturbing effect value, C is methane concentration, and L is absorber thickness, and D is detector drift, and B (t) is bias light interference, K (λ
1), K (λ
2) be optical filter filter factor.
Because the time of twice light signal input is very approaching, bias light now disturbs B (t) can think equal, light path disturbing effect value β (λ
1), β (λ
2) also negligible, initial light intensity is the same and optical filter filter factor is also equal, again because two groups of light use same photodetector 207, so detector drift D is the same.
Measure electric signal
Can obtain methane concentration is
Wherein,
Thereby obtain the methane concentration C in gas to be measured.
Claims (7)
1. a dual-wavelength difference sensing methane concentration device, is characterized in that:
Comprise light source, light processing module, signal processing module and signal analyse block;
Wherein
Described light source is used for sending light signal;
Described smooth processing module comprises an optical filtering module, a photodetector, a rotation lighting machine and an air chamber;
Described optical filtering module, for filtering the light signal that light source sends, passes through the light signal of one group of first wavelength and the light signal of one group of second wave length;
In described air chamber, circulation has gas to be measured;
Described rotation lighting machine periodically makes above-mentioned two groups of light signals be sent to described photodetector through described air chamber respectively;
Light signal is converted to electric signal by described photodetector;
Described signal processing module is for carrying out filtering and amplification to the electric signal of described smooth processing module output;
Described signal analyse block is for analyzing the electric signal of described signal processing module output;
Described optical filtering module comprises convex lens, right cylinder light chamber, upper optical filter, lower optical filter;
Described convex lens are converted to parallel optical signal for the light signal that light source is sent;
Described upper optical filter and lower optical filter are arranged at the light path midsection of described right cylinder light chamber;
Described upper optical filter can be the light signal of the first wavelength by centre wavelength;
The light signal that described lower optical filter can be second wave length by centre wavelength;
Described rotation lighting machine is arranged at the end of described right cylinder light chamber;
Described rotation lighting machine, air chamber rotate together with photodetector;
Described rotation lighting machine comprises a logical light window;
The every rotation one of described rotation lighting machine is enclosed, and described logical light window has upper and lower two stop positions;
When stop position above stopping at, the light signal of described the first wavelength passes from described logical light window;
In the time of stop position below stopping at, the light signal of described second wave length passes from described logical light window.
2. dual-wavelength difference sensing methane concentration device according to claim 1, wherein:
Described light source is LED or semiconductor laser.
3. dual-wavelength difference sensing methane concentration device according to claim 1, wherein:
The filter factor of described upper optical filter and lower optical filter equates.
4. dual-wavelength difference sensing methane concentration device according to claim 1, wherein:
Adopt stepper motor to drive described rotation lighting machine, air chamber and photodetector rotation.
5. dual-wavelength difference sensing methane concentration device according to claim 1, wherein:
The entrance of described air chamber, outlet are prism wedge;
Described air chamber rear and front end is two plane mirrors;
The two ends up and down of described air chamber are dustproof network structure.
6. dual-wavelength difference sensing methane concentration device according to claim 1, wherein:
Described photodetector is photoelectron emissions detector or photoconductive detector or photovoltaic detector.
7. dual-wavelength difference sensing methane concentration device according to claim 1, wherein:
Described the first wavelength is 1.650 μ m;
Described second wave length is 1.620 μ m.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320656317.1U CN203720078U (en) | 2013-10-23 | 2013-10-23 | Double wavelength difference methane concentration sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320656317.1U CN203720078U (en) | 2013-10-23 | 2013-10-23 | Double wavelength difference methane concentration sensor |
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| Publication Number | Publication Date |
|---|---|
| CN203720078U true CN203720078U (en) | 2014-07-16 |
Family
ID=51159218
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201320656317.1U Expired - Fee Related CN203720078U (en) | 2013-10-23 | 2013-10-23 | Double wavelength difference methane concentration sensor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN203720078U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103558165A (en) * | 2013-10-23 | 2014-02-05 | 国家电网公司 | Dual-wavelength difference methane concentration sensor |
| CN107328722A (en) * | 2016-04-21 | 2017-11-07 | 霍尼韦尔国际公司 | Dual wavelength source detector |
-
2013
- 2013-10-23 CN CN201320656317.1U patent/CN203720078U/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103558165A (en) * | 2013-10-23 | 2014-02-05 | 国家电网公司 | Dual-wavelength difference methane concentration sensor |
| CN103558165B (en) * | 2013-10-23 | 2015-11-04 | 国家电网公司 | A kind of dual-wavelength difference methane concentration sensor |
| CN107328722A (en) * | 2016-04-21 | 2017-11-07 | 霍尼韦尔国际公司 | Dual wavelength source detector |
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|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20140716 |