CN109358013A - Protect adjustable gas probe, optical fiber gas concentration measuring system and method - Google Patents
Protect adjustable gas probe, optical fiber gas concentration measuring system and method Download PDFInfo
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- CN109358013A CN109358013A CN201811458804.0A CN201811458804A CN109358013A CN 109358013 A CN109358013 A CN 109358013A CN 201811458804 A CN201811458804 A CN 201811458804A CN 109358013 A CN109358013 A CN 109358013A
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- 239000000523 sample Substances 0.000 title claims abstract description 56
- 239000013307 optical fiber Substances 0.000 title claims abstract description 38
- 238000000034 method Methods 0.000 title abstract description 17
- 239000007789 gas Substances 0.000 claims abstract description 121
- 239000012495 reaction gas Substances 0.000 claims abstract description 24
- 238000001914 filtration Methods 0.000 claims abstract description 15
- 229920000914 Metallic fiber Polymers 0.000 claims abstract description 14
- 229920000573 polyethylene Polymers 0.000 claims abstract description 12
- 230000003287 optical effect Effects 0.000 claims description 193
- 238000010521 absorption reaction Methods 0.000 claims description 31
- 238000012360 testing method Methods 0.000 claims description 25
- 238000001514 detection method Methods 0.000 claims description 15
- 238000006243 chemical reaction Methods 0.000 claims description 11
- 230000001681 protective effect Effects 0.000 claims description 11
- 230000031700 light absorption Effects 0.000 claims description 10
- 238000004891 communication Methods 0.000 claims description 5
- 238000013461 design Methods 0.000 claims description 4
- 230000000694 effects Effects 0.000 claims description 4
- 239000003344 environmental pollutant Substances 0.000 claims description 3
- 238000000691 measurement method Methods 0.000 claims description 3
- 231100000719 pollutant Toxicity 0.000 claims description 3
- 230000008054 signal transmission Effects 0.000 claims description 3
- 238000004364 calculation method Methods 0.000 claims description 2
- 238000001816 cooling Methods 0.000 claims description 2
- 230000007774 longterm Effects 0.000 abstract description 4
- 230000007613 environmental effect Effects 0.000 abstract description 2
- 239000010410 layer Substances 0.000 description 13
- 239000002184 metal Substances 0.000 description 7
- 230000003321 amplification Effects 0.000 description 6
- 238000003199 nucleic acid amplification method Methods 0.000 description 6
- 239000000835 fiber Substances 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- 239000000843 powder Substances 0.000 description 4
- 230000008859 change Effects 0.000 description 3
- 239000000428 dust Substances 0.000 description 3
- 238000011109 contamination Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- -1 polyethylene Polymers 0.000 description 2
- 239000002356 single layer Substances 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- 239000004698 Polyethylene Substances 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 150000001335 aliphatic alkanes Chemical class 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 239000012792 core layer Substances 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000008439 repair process Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 230000003595 spectral effect Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
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Abstract
The present disclosure discloses protection adjustable gas probe, optical fiber gas concentration measuring system and methods, the sequentially connected controller of optical fiber gas concentration measuring system, Distributed Feedback Laser module, circulator and protection adjustable gas probe, the circulator, photodetector and controller are sequentially connected；The reaction gas chamber of gas probe part is coated by the metallic fiber sintered felt of multilayer difference filtering accuracy and the high molecular polythene film of waterproof and breathable, guarantee gas probe environmental suitability with higher, system can be run steadily in the long term in various severe engineering-environments.
Description
Technical field
This disclosure relates to technical field of optical fiber detection, more particularly to protection adjustable gas probe, optical fiber gas concentration
Measuring system and method.
Background technique
Spectral absorption method is very common technological means in fiber-optic fiber gas detection field.This method utilizes specific wavelength
Light when transmiting or reflect in certain gas the decaying of optical power carry out the concentration of detection gas.Since every kind of gas has certainly
Oneself characteristic absorpting spectruming line will generate light suction when the wavelength of light of transmission or reflection is overlapped with the absorption line of gas
Phenomenon is received, optical power can occur significantly to decay, and attenuation is related with the concentration of gas.
When a branch of optical power is I0Directional light by gas chamber containing tested gas when, if the wavelength of optical signal covers
Optical power attenuation can occur for the absorption line spectrum of tested gas, the then optical signal exported.According to Bill-youth primary (Beer-Lambert)
Law, Output optical power I (λ) and input optical power I0Relationship between (λ), gas concentration C are as follows:
Wherein, αλIt is absorption coefficient of the gas in a length of λ of light wave, L is the length for absorbing path.
It can be obtained by formula (2-1):
When wavelength of optical signal λ is constant, αλIt is a constant, L can measure to obtain.So by detecting I0(λ) and I
(λ) can be obtained by gas concentration.
When detecting tested gas concentration using Spectrum Absorption Principle, detection accuracy is influenced whether there are many factor: such as
The power and wavelength of the light source of internal system is drifted about, couple state variation, photoelectric device index are drifted about at optical signal link couples；
The dust and condensation vapor of external environment cause to seriously affect the accuracy of measurement by the Strength Changes etc. of light signal.It is existing
In technology in order to overcome internal system enchancement factor influence, the method generallyd use mainly have Difference Absorption detection method and
Harmonic detecting method；In order to overcome external environment to the influence of detection accuracy, the technology generallyd use is burnt using metal powder
Knot filter core or single-layer metal filter screen are filtered under test gas.
But currently used Difference Absorption detection method and harmonic detecting method mostly need complicated circuit, algorithm
With optical path etc..The production cost for directly or indirectly increasing sensor is unfavorable for the application and popularization of sensor itself.And
Due to the limitation of metal powder sintered filter element and single-layer metal filter screen, the filtering essence of the metal powder sintered filter element after design
Degree range is small and pollutant carrying capacity can not be changed, i.e., has fixed, made to the filter capacity of dust and to the blocking capability of steam
Environmentally just there is significant limitation.
Disclosure
In order to solve the deficiencies in the prior art, present disclose provides protection adjustable gas probes, can on protection effect
It is adjusted according to the actual needs, meets different grades of protection requirements.
To achieve the goals above, the application uses following technical scheme:
Embodiment of the disclosure discloses protection adjustable gas probe, including the reaction gas set gradually from inside to outside
Room, filter layer, outside protective pipe, the filter layer is coated on the outside of the reaction gas chamber, and the both ends of filter layer pass through fastening
Part is fastened on reaction gas chamber, and optical fiber is exported optical signal to the reaction gas room by optical fiber collimator, outside the optical fiber
For optical cable, optical cable and reaction gas chamber are linked together using connecting sleeve, the outside protective pipe is covered in the outside of filter layer；
Wherein, the filter layer plays protective action to reaction gas chamber, and the filter layer includes being cut into and reacting gas chamber
The metallic fiber sintered felt and high molecular polythene film of wide rectangle, the structure of the filter layer is according to the protection of gas probe
Grade matches.
If desired further technical solution increases the filter area of gas probe, then metallic fiber sintered felt and height
Molecular polyethylene film is folded up carries out volume bundle again, forms the shape of foldable filter element；Or
If desired the pollutant carrying capacity for increasing gas probe then increases the number of plies of metallic fiber sintered felt volume bundle；Or
If desired increase the range of gas probe filtering accuracy, then burnt by the metallic fiber that situation increases different filtering accuracies
Tie felt；Or
If desired the anti-steam coagulability for increasing gas probe, then increase the number of plies of high molecular polythene film.
Further technical solution is provided with reflecting mirror in the reaction gas room.
Embodiment of the disclosure discloses optical fiber gas concentration measuring system, comprising: sequentially connected controller, DFB
Laser module, circulator and protection adjustable gas probe, the circulator, photodetector and controller are sequentially connected；
The controller controls Distributed Feedback Laser module output optical signal and obtains the light that Distributed Feedback Laser module is fed back
The optical power of signal；
The optical signal of the Distributed Feedback Laser module output enters protection adjustable gas probe, optical signal by circulator
It is output in the reaction gas chamber of open optical path after into gas probe by optical fiber collimator, the optical signal is in reaction gas room
It is sufficiently reacted under test gas, is then reflected by reflecting mirror, receive optical signal, light again by optical fiber collimator
Signal enters photodetector by circulator, and the photodetector converts optical signals to weak current signal and passes through amplification
Device is converted to voltage signal and is transmitted to controller；
The controller handles voltage signal to obtain the number for representing optical power by included analog-to-digital conversion module
Word signal, the controller is eventually by the optical power and photodetector reception light to Distributed Feedback Laser module output optical signal
The value of the optical power of signal carries out operation and obtains the concentration of under test gas.
Further technical solution, the controller are connected by SCI bus with computer, and by the under test gas of acquisition
Concentration be uploaded to computer, the computer carries out display and Threshold Alerts to result.
Further technical solution, the Distributed Feedback Laser module include Distributed Feedback Laser and control circuit part, the control
Circuit part processed is used for and the Output optical power of cooling piece and detection Distributed Feedback Laser in controller communication, control Distributed Feedback Laser
Effect.
Further technical solution, the controller pass through the control circuit portion of spi bus and the Distributed Feedback Laser module
Divide communication, controls the driving current value of Distributed Feedback Laser to control the wavelength and optical power of Distributed Feedback Laser output optical signal, simultaneously
The controller communicates the Output optical power for obtaining Distributed Feedback Laser by spi bus.
Further technical solution, there are three port, first ports to be connected with Distributed Feedback Laser module, connect for the circulator
Receive the optical signal of DFB laser module output；Second port is connected with gas probe, and the optical signal of first port is passed through light
Fibre is transferred to gas probe, and the optical signal transmission that gas probe is returned is to third port, third port and photodetector
It is connected, third port is by optical fiber output optical signal to photodetector.
Further technical solution, the photodetector are the PD pipe with optical fiber pigtail, and design parameter is according to DFB laser
The output optical signal wavelength of device module is adjusted.
Embodiment of the disclosure discloses the measurement method of optical fiber gas concentration measuring system, comprising:
Controller controls the optical signal that Distributed Feedback Laser module Output optical power and wavelength are fixed, and the wavelength of optical signal is located at
Except the characteristic absorption wavelength of under test gas, and pass through the optical power value of Distributed Feedback Laser module acquisition output optical signal；
Reflected optical power value when absorbing reaction unglazed by photodetector detection optical signal；
The practical optical link loss of the optical path can be obtained by input and output optical power value of optical signal when reactionless；
Controller controls the optical signal that Distributed Feedback Laser module Output optical power and wavelength are fixed, the wavelength of optical signal again
Being located just at the characteristic absorption wavelength of under test gas and absorption coefficient is fixed constant, and is obtained by Distributed Feedback Laser module defeated
The optical power value of optical signals；
Optical signal, which is detected, by photodetector carries out the optical power value that light absorption reaction back reflection is returned；
Practical optical link loss is that the wavelength of output optical signal is the unglazed suction of under test gas characteristic absorption wavelength optical signal
The optical power theoretical value that time receiving returns, as input optical power I0(λ) carries out the optical power value that light absorption reaction back reflection is returned
Concentration calculation formula is substituted into as Output optical power I (λ) as optical power actual measured value:
When wavelength of optical signal λ is constant, αλIt is a constant, L can measure to obtain, so, by detecting I0(λ) and I
(λ) obtains gas concentration.
It is the characteristic absorption wavelength optical signal of under test gas by the practical optical link loss and output wavelength that measure
If optical power value returns the optical power for being emitted back towards and, even calculated value and measured value when the unglazed absorbing reaction of the optical signal can be calculated
Equal, representing under test gas concentration is 0, if calculated value is greater than measured value, that is, representing under test gas concentration is not 0.
Voltage analog signal is converted to digital letter by the analog-to-digital conversion module on controller by further technical solution
Number, which represents reflected optical power value, and controller obtains the Output optical power of the optical signal and is reflected back
It, both can be by optical power attenuation formula after the optical power come:
The optical power attenuation of the optical link is calculated.
Wherein dB is the unit of optical power attenuation；PinFor input optical power；PoutFor reflected optical power.
Compared with prior art, the beneficial effect of the disclosure is:
The internal factor that the method for disclosure self-correcting eliminates system well influences detection accuracy, does not need difference
The additional reference channel of absorption detecting method and the complicated circuit of harmonic detecting method, reduce the complexity of detection system ultimate attainmently
Degree makes hardware cost be effectively controlled；It also extremely simplifies, is compared with the traditional method in software algorithm, significantly reduce
The response time shortens dramatically while system complexity and cost, improves the stability and practicability of system.
It is to be measured that gas probe in the disclosure has used the flexible metal fiber sintering felt serving of a variety of different filtering accuracies to carry out
The filtering of gas can also increase filter area and contamination capacity by increasing fold and the number of plies, be compared with the traditional method, gram
Taken the narrow range of metal powder sintered filter element filtering accuracy, contamination capacity is small, not can increase filter area, it is frangible the features such as,
Enhance adaptability of the sensor in various severe application environments and increase the use distance of probe, while ensuring system energy
Operation steady in a long-term.
The high molecular polythene film that gas probe in the disclosure increases waterproof and breathable carries out the filtering of under test gas, with
Conventional method is compared, and the anti-steam coagulability of gas probe is greatly improved, and is similar to first when gas probe is applied to detection
When this kind of gas to water vapor sensitive of alkane, detection system stable fortune for a long time in the very high environment of air humidity still can ensure that
Row.
Detailed description of the invention
The accompanying drawings constituting a part of this application is used to provide further understanding of the present application, and the application's shows
Meaning property embodiment and its explanation are not constituted an undue limitation on the present application for explaining the application.
Fig. 1 is the gas concentration measurement system schematic of disclosure one or more examples of implementation；
Fig. 2 is the gas probe sectional view of disclosure one or more examples of implementation；
Fig. 3 is that the gas probe of disclosure one or more examples of implementation removes the schematic diagram of outside protective pipe；
Fig. 4 is the gas probe outside protective pipe schematic diagram of disclosure one or more examples of implementation；
In figure, 1, computer, 2, controller, 3, Distributed Feedback Laser module, 4, circulator, 5, gas probe, 6, photodetection
Device, 7, amplifier, 5-1, connectivity kit, 5-2, outside protective pipe, 5-3, reflecting mirror, 5-4, filter layer, 5-5, reaction gas chamber, 5-6,
Fastener, 5-7, optical fiber, 5-8, optical cable, 5-9, optical fiber collimator.
Specific embodiment
It is noted that following detailed description is all illustrative, it is intended to provide further instruction to the application.Unless another
It indicates, all technical and scientific terms used herein has usual with the application person of an ordinary skill in the technical field
The identical meanings of understanding.
It should be noted that term used herein above is merely to describe specific embodiment, and be not intended to restricted root
According to the illustrative embodiments of the application.As used herein, unless the context clearly indicates otherwise, otherwise singular
Also it is intended to include plural form, additionally, it should be understood that, when in the present specification using term "comprising" and/or " packet
Include " when, indicate existing characteristics, step, operation, device, component and/or their combination.
In a kind of typical embodiment of the application, as shown in Figure 1, optical fiber gas concentration measuring system is provided, by
Shown in Fig. 1, including computer 1, controller 2, Distributed Feedback Laser module 3, circulator 4, gas probe 5, photodetector 6, amplification
7 seven part of device composition.
1 major function of computer is the display and further practical application for gas detection result, for example is reported with generating
Alert linkage etc., if can reach better display effect, can be replaced with other hosts with RS232 communications protocol.
Controller 2 in embodiment of the disclosure uses more general dsp chip, and model is TMS320F28335,
Chip arithmetic speed with higher and functional module abundant.
The general output wavelength of Distributed Feedback Laser module 3 controls in C+L wave band section, can more embody Fibre Optical Sensor long distance in this way
Advantage from measurement, subject to the characteristic absorption wavelength of the gas specifically optionally measured.
There are three port, first ports to receive the optical signal of Distributed Feedback Laser module output for circulator 4；Second port is by
The optical signal of Single port is transferred to gas probe by optical fiber, and the optical signal transmission that gas probe 5 is returned is to third port,
Third port is by optical fiber output optical signal to photodetector.Its light passing is lost mainly according to the output of Distributed Feedback Laser module
Wavelength of optical signal can adjust circulator parameter by actual conditions.
Photodetector 6 is the PD pipe with optical fiber pigtail, and design parameter is according to the output optical signal wave of Distributed Feedback Laser module
Long be adjusted both may be used.
Amplifier 7 carries out light current pressure using the amplifier chip AD8605ARTZ that AD company is specifically applied to photodetector
Amplification, and pass through the amplification factor that adjustable potentiometer chip AD5245BRJ5 controls amplifier on software.
The reaction gas chamber of gas probe part by multilayer difference filtering accuracy metallic fiber sintered felt and waterproof and breathable
High molecular polythene film is coated, and guarantees gas probe environmental suitability with higher, in various severe engineering-environments
Middle system can be run steadily in the long term.
After controller 2 receives enough digital signals, tested gas concentration value can be calculated according to digital quantity.
Photodetector will reflect back into the optical signal come and be converted to weak current analog signal, and output is to amplifier, amplification
Weak current analog signal is converted to voltage analog signal by device, and line amplitude of going forward side by side amplification is exported to the analog-to-digital conversion of controller
Analog voltage signal can be converted to digital signal and is stored in controller by module, analog-to-digital conversion module.
In the typical embodiment of the another kind of the application, gas probe is provided as shown in Figure 2, including optical cable 5-8, company
Joint kit 5-1, optical fiber collimator 5-9, reaction gas chamber 5-5, reflecting mirror 5-3, filter layer 5-4, fastener 5-6 and outside protective pipe
5-2 composition.
When needing to change the degree of protection of gas probe because of use environment change, as shown in Figure 3-4, gas is screwed out
The outside protective pipe of probe unlocks the fastener at filter layer both ends, then changes filter layer and both may be used.
Metallic fiber sintered felt and high molecular polythene film are generally cut into the rectangle wide with gas chamber is reacted, then root
Both may be used according to needing to carry out reaction gas chamber to roll up bundle；If desired the filter area for increasing gas probe, then metallic fiber sintered felt
It is folded up with high molecular polythene film and carries out volume bundle again, form the shape of foldable filter element.If desired increase receiving for gas probe
Dirty ability, the then number of plies for increasing metallic fiber sintered felt volume bundle both may be used.If desired increase the range of gas probe filtering accuracy, then
Both may be used by the metallic fiber sintered felt that situation increases different filtering accuracies.If desired the anti-steam for increasing gas probe condenses energy
Power, the then number of plies for increasing high molecular polythene film both may be used.Specific service condition is depending on site environment and system requirements.
It after replacing well filtering layer, is fixed with two fasteners at reaction gas chamber both ends and both may be used, it is only necessary to guarantee to fix
The internal diameter that filter layer outer diameter afterwards is less than outside protective pipe both may be used.
Another embodiment of the present disclosure, is based on above-mentioned apparatus, measures gas concentration value using following methods:
Step 1: the optical link loss of system is obtained, the self-correcting for system.
Controller, that is, dsp chip TMS320F28335 is defeated by the SPI communication module control Distributed Feedback Laser module in chip
The optical signal of constant power and wavelength out, and the performance number of output optical signal is transferred to controller chip.The wave of the optical signal
Length is not in the characteristic absorption wavelength of under test gas, i.e., the optical power of optical signal is only influenced by optical link loss.The optical signal
Circulator, gas probe arrival photodetector are passed sequentially through, photodetector converts optical signals to weak current signal, passes through
Weak current signal is converted to weak voltage signal by the amplifier chip AD8605ARTZ for being specifically applied to photodetector, and will be weak
Voltage signal is amplified to thousand times of magnitudes, reaches millivolt level, and the analog-to-digital conversion module on controller chip can be captured and detects.So
Voltage analog signal is converted to by digital signal by the analog-to-digital conversion module on controller chip afterwards, which represents
Reflected optical power value.After controller chip obtains Output optical power and the reflected optical power of the optical signal, both
It can be by optical power attenuation formula
The optical power attenuation of the optical link is calculated.
Wherein dB is the unit of optical power attenuation；PinFor input optical power；PoutFor reflected optical power.
Step 2: obtain output optical signal wavelength be under test gas characteristic absorption wavelength optical signal without light absorption when return
The optical power theoretical value returned.
The optical power attenuation that optical link is measured and be calculated by the first step, when controller controls Distributed Feedback Laser module
When output wavelength is that under test gas characteristic absorption wavelength immobilizes, optical power also immobilizes.Distributed Feedback Laser module can incite somebody to action
The performance number of output optical signal is transferred to controller chip, and dsp chip is the practical optical power of optical link obtained by the first step
Reflected optical power theoretical value is calculated by formula (5-1) in pad value.
Step 3: the wavelength for obtaining output optical signal is that under test gas characteristic absorption wavelength optical signal returns when having light absorption
The optical power actual measured value returned.
As the process of the first step, when controller controls Distributed Feedback Laser module output wavelength as the suction of under test gas feature
When receipts wavelength immobilizes, for optical signal after optical link carries out light absorption reaction, it is real that measurement obtains reflected optical power
Border measured value.
Step 4: under test gas concentration is calculated
The wavelength for the output optical signal that second step is obtained is under test gas characteristic absorption wavelength optical signal without light absorption
When the obtained wavelength of output optical signal of the optical power theoretical value that returns and third step be the under test gas characteristic absorption wavelength time
The input optical power I that signal has the optical power actual measured value returned when light absorption to substitute into formula (2-2) respectively0(λ) and output
In optical power I (λ), when being equal under test gas characteristic absorption wavelength due to wavelength of optical signal and immobilize, absorption coefficientλFor
Constant, L can measure and obtain.Both accurate under test gas concentration value can be calculated.
While the sensor of the disclosure has self-correcting function, optical path, circuit and algorithm are simplified, improve system
Achieve the purpose that low cost while stability；And by improve gas probe make sensor different moisture levels is big, more than dust
Severe application environment is also able to maintain operation steady in a long-term.
The foregoing is merely preferred embodiment of the present application, are not intended to limit this application, for the skill of this field
For art personnel, various changes and changes are possible in this application.Within the spirit and principles of this application, made any to repair
Change, equivalent replacement, improvement etc., should be included within the scope of protection of this application.
Claims (10)
1. protecting adjustable gas probe, characterized in that including the reaction gas chamber, filter layer, outer guarantor set gradually from inside to outside
Pillar, the filter layer is coated on the outside of the reaction gas chamber, and the both ends of filter layer are fastened on reaction gas by fastener
On room, optical fiber is exported optical signal to the reaction gas room by optical fiber collimator, is optical cable outside the optical fiber, is utilized connection
Casing links together optical cable and reaction gas chamber, and the outside protective pipe is covered to be set in the outside of filter layer, the reaction gas room
It is equipped with reflecting mirror；
Wherein, the filter layer plays protective action to reaction gas chamber, and the filter layer includes being cut into and to react gas chamber wide
Rectangle metallic fiber sintered felt and high molecular polythene film, the structure of the filter layer is according to the degree of protection of gas probe
Match.
2. protection adjustable gas probe as described in claim 1, characterized in that if desired increase the filtering surface of gas probe
Product, then fold up metallic fiber sintered felt and high molecular polythene film and carry out volume bundle again, form the shape of foldable filter element；Or
If desired the pollutant carrying capacity for increasing gas probe then increases the number of plies of metallic fiber sintered felt volume bundle；Or
If desired the range for increasing gas probe filtering accuracy, then increase the metallic fiber sintered of different filtering accuracies by situation
Felt；Or
If desired the anti-steam coagulability for increasing gas probe, then increase the number of plies of high molecular polythene film.
3. optical fiber gas concentration measuring system, characterized in that include: sequentially connected controller, Distributed Feedback Laser module, annular
Device and any protection adjustable gas probe of claim 1-2, the circulator, photodetector and controller are successively
Connection；
The controller controls Distributed Feedback Laser module output optical signal and obtains the optical signal that Distributed Feedback Laser module is fed back
Optical power；
The optical signal of the Distributed Feedback Laser module output enters protection adjustable gas probe by circulator, and optical signal enters
Be output in the reaction gas chamber of open optical path after gas probe by optical fiber collimator, the optical signal in reaction gas room and to
It surveys gas sufficiently to be reacted, then be reflected by reflecting mirror, receive optical signal, optical signal again by optical fiber collimator
Enter photodetector by circulator, the photodetector converts optical signals to weak current signal and turns by amplifier
It is changed to voltage signal and is transmitted to controller；
The controller handles voltage signal by included analog-to-digital conversion module to obtain the number letter for representing optical power
Number, the controller is eventually by the optical power and photodetector reception optical signal to Distributed Feedback Laser module output optical signal
Optical power value carry out operation obtain the concentration of under test gas.
4. optical fiber gas concentration measuring system as claimed in claim 3, characterized in that the controller by SCI bus with
Computer is connected, and the concentration of the under test gas of acquisition is uploaded to computer, and the computer carries out display and threshold to result
Value alarm.
5. optical fiber gas concentration measuring system as claimed in claim 3, characterized in that the Distributed Feedback Laser module includes DFB
Laser and control circuit part, the control circuit part be used for controller communication, control Distributed Feedback Laser in cooling piece and
Detect the effect of the Output optical power of Distributed Feedback Laser.
6. optical fiber gas concentration measuring system as claimed in claim 3, characterized in that the controller by spi bus with
The control circuit part of the Distributed Feedback Laser module communicates, and controls the driving current value of Distributed Feedback Laser to control Distributed Feedback Laser
The wavelength and optical power of output optical signal, while the controller communicates the output light function for obtaining Distributed Feedback Laser by spi bus
Rate.
7. optical fiber gas concentration measuring system as claimed in claim 3, characterized in that the circulator is there are three port, and the
Single port is connected with Distributed Feedback Laser module, receives the optical signal of Distributed Feedback Laser module output；Second port and gas probe phase
Even, the optical signal transmission for the optical signal of first port being transferred to gas probe, and gas probe being returned by optical fiber gives the
Three ports, third port are connected with photodetector, and third port is by optical fiber output optical signal to photodetector.
8. optical fiber gas concentration measuring system as claimed in claim 3, characterized in that the photodetector is band optical fiber tail
Fine PD pipe, design parameter are adjusted according to the output optical signal wavelength of Distributed Feedback Laser module.
9. the measurement method of optical fiber gas concentration measuring system, characterized in that include:
Controller controls the optical signal that Distributed Feedback Laser module Output optical power and wavelength are fixed, and the wavelength of optical signal is located to be measured
Except the characteristic absorption wavelength of gas, and pass through the optical power value of Distributed Feedback Laser module acquisition output optical signal；
Reflected optical power value when absorbing reaction unglazed by photodetector detection optical signal；
The practical optical link loss of the optical path can be obtained by input and output optical power value of optical signal when reactionless；
Controller controls the optical signal that Distributed Feedback Laser module Output optical power and wavelength are fixed again, and the wavelength of optical signal is just
Characteristic absorption wavelength and absorption coefficient positioned under test gas are fixed constant, and obtain output light by Distributed Feedback Laser module
The optical power value of signal；
Optical signal, which is detected, by photodetector carries out the optical power value that light absorption reaction back reflection is returned；
Practical optical link loss be output optical signal wavelength be under test gas characteristic absorption wavelength optical signal without light absorption when
The optical power theoretical value of return, as input optical power I0(λ) carries out the optical power value conduct that light absorption reaction back reflection is returned
Optical power actual measured value substitutes into concentration calculation formula as Output optical power I (λ):
When wavelength of optical signal λ is constant, αλIt is a constant, L can measure to obtain, so, by detecting I0(λ) and I (λ)
To gas concentration.
10. the measurement method of optical fiber gas concentration measuring system as claimed in claim 9, characterized in that by controller
Analog-to-digital conversion module voltage analog signal is converted into digital signal, which represents reflected optical power
Value, both can be by optical power attenuation formula after controller obtains Output optical power and the reflected optical power of the optical signal:
The optical power attenuation of the optical link is calculated.
Wherein dB is the unit of optical power attenuation；PinFor input optical power；PoutFor reflected optical power.
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101149342A (en) * | 2007-10-25 | 2008-03-26 | 南京树声科技有限公司 | Laser gas remote measurement method and device |
| CN101319989A (en) * | 2007-06-08 | 2008-12-10 | 派克森公司 | Gas concentration detection method and apparatus thereof |
| CN203479694U (en) * | 2013-05-07 | 2014-03-12 | 武汉理工大学 | Optical fiber gas sensing probe with quick response |
| CN104237161A (en) * | 2014-10-15 | 2014-12-24 | 中国科学院合肥物质科学研究院 | Multi-component real-time online remote monitoring device and method for coal spontaneous combustion indicator gas |
| CN105823755A (en) * | 2016-04-07 | 2016-08-03 | 南京大学 | Self-mixing gas absorption sensing system based on tunable semiconductor laser |
| CN205593921U (en) * | 2016-04-29 | 2016-09-21 | 何祥林 | Mining laser full -scale range methane detection device based on TDLAS |
| CN107991267A (en) * | 2017-11-29 | 2018-05-04 | 珠海任驰光电科技有限公司 | The tunable diode laser absorption spectroscopy gas-detecting device and method of wavelength agile |
| CN209280556U (en) * | 2018-11-30 | 2019-08-20 | 珠海任驰光电科技有限公司 | Protect adjustable gas probe, optical fiber gas concentration measuring system |
-
2018
- 2018-11-30 CN CN201811458804.0A patent/CN109358013A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101319989A (en) * | 2007-06-08 | 2008-12-10 | 派克森公司 | Gas concentration detection method and apparatus thereof |
| CN101149342A (en) * | 2007-10-25 | 2008-03-26 | 南京树声科技有限公司 | Laser gas remote measurement method and device |
| CN203479694U (en) * | 2013-05-07 | 2014-03-12 | 武汉理工大学 | Optical fiber gas sensing probe with quick response |
| CN104237161A (en) * | 2014-10-15 | 2014-12-24 | 中国科学院合肥物质科学研究院 | Multi-component real-time online remote monitoring device and method for coal spontaneous combustion indicator gas |
| CN105823755A (en) * | 2016-04-07 | 2016-08-03 | 南京大学 | Self-mixing gas absorption sensing system based on tunable semiconductor laser |
| CN205593921U (en) * | 2016-04-29 | 2016-09-21 | 何祥林 | Mining laser full -scale range methane detection device based on TDLAS |
| CN107991267A (en) * | 2017-11-29 | 2018-05-04 | 珠海任驰光电科技有限公司 | The tunable diode laser absorption spectroscopy gas-detecting device and method of wavelength agile |
| CN209280556U (en) * | 2018-11-30 | 2019-08-20 | 珠海任驰光电科技有限公司 | Protect adjustable gas probe, optical fiber gas concentration measuring system |
Non-Patent Citations (1)
| Title |
|---|
| 王艳菊;王玉田;张玉燕;: "差分吸收式甲烷气体传感系统的研究", 仪器仪表学报, no. 12, pages 1647 - 1650 * |
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