CN207636485U - The tunable diode laser absorption spectroscopy gas-detecting device of wavelength agile - Google Patents
The tunable diode laser absorption spectroscopy gas-detecting device of wavelength agile Download PDFInfo
- Publication number
- CN207636485U CN207636485U CN201721633127.2U CN201721633127U CN207636485U CN 207636485 U CN207636485 U CN 207636485U CN 201721633127 U CN201721633127 U CN 201721633127U CN 207636485 U CN207636485 U CN 207636485U
- Authority
- CN
- China
- Prior art keywords
- optical signal
- laser
- wavelength
- gas
- light intensity
- 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 tunable diode laser absorption spectroscopy gas-detecting devices of wavelength agile, device includes laser, circulator, reflective probe, photodetector and Date Conversion Unit, when laser is activated output wavelength and light intensity with driving current mechanical periodicity optical signal, it is transferred to circulator, circulator receives the optical signal of laser, and give the optical signal transmission to reflective probe, reflective opening light path of the probe containing one section of fixed range, realize the interaction of optical signal and tested gas, and the optical signal for returning to reflective probe is to photodetector, convert optical signals to weak current analog signal, it exports to Date Conversion Unit, obtain tested gas concentration value.The light intensity variation in each period and wavelength change, are divided into two stages.Using first stage light intensity variable quantity of the wavelength far from tested gas absorption spectrum line, compensation wavelength covering is tested the second stage light intensity variable quantity of gas absorption spectrum line, improves measurement accuracy and long-time stability.
Description
Technical field
The utility model is related to a kind of tunable diode laser absorption spectroscopy gas-detecting devices of wavelength agile.
Background technology
In fiber-optic fiber gas detection field, spectral absorption method is most common detection technique.This method utilizes specific wavelength
Light when transmiting or reflect in gas the decaying of light intensity carry out the concentration of detection gas.Each gas has the feature of oneself
Absorption line will produce light absorption phenomenon when the optical wavelength that light source is sent out is overlapped with the absorption line of gas, and light intensity can occur
A degree of decaying, attenuation are related with the concentration of gas.
When a branch of light intensity is I0Directional light by gas chamber containing tested gas when, if optical signal covering is tested gas
Absorption line, then transmission or reflection light intensity decay.According to Beer-Lambert (Beer-Lambert) law, output intensity I
(λ) and input light intensity I0Relationship between (λ), gas concentration C is：
Wherein, αλIt is tested 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 (1-1)：
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 tested gas concentration.
When detecting tested gas concentration using Spectrum Absorption Principle, accuracy of detection is influenced whether there are many factor：Light source
Wave length shift, tested gas absorption spectrum line are influenced by temperature, pressure.In order to overcome shadow of these factors to accuracy of detection
It rings, the technology generally used is tunable diode laser absorption spectroscopy (TDLAS) technology.
TDLAS technologies are used as light source, profit using line width much smaller than the distributed feedback laser (DFB) of traditional infrared light source
With the driving current of triangular wave or saw tooth wave shape, linear modulation is carried out to the wavelength of light source output, wavelength scanning range is made to cover
Lid is tested the absorption line of gas.According to the attenuation of luminous power, the concentration for being tested gas is judged.
But TDLAS technologies focus on solving be optical source wavelength drift and tested gas absorption spectrum line variation to detection essence
The influence of degree.And the variation of couple state, the drift of photoelectric device index etc. at the power stability of light source, optical signal link couples
Enchancement factor can equally cause the Strength Changes for being measured optical signal, seriously affect the accuracy of measurement.
Utility model content
The utility model is to solve the above-mentioned problems, it is proposed that a kind of tunable semiconductor laser spectrum gas of wavelength agile
Device and method is surveyed in physical examination, and the utility model utilizes wavelength agile technology, compensates for power excursion, the optical signal link coupling of light source
Light signal strength caused by the enchancement factors such as the variation of couple state, the drift of photoelectric device index changes at conjunction, improves gas
The precision and long-time stability of detection.
To achieve the goals above, the utility model adopts the following technical solution：
A kind of tunable semiconductor laser spectrum gas-detecting device of wavelength agile, including laser, circulator, reflection
Formula probe, photodetector and Date Conversion Unit, wherein：
Output wavelength and light intensity are transferred to annular with the optical signal of drive current variations when the laser is activated
Device, circulator receives the optical signal of laser, and gives reflective probe, reflective probe solid containing one section the optical signal transmission
The opening light path of set a distance realizes the interaction of optical signal and tested gas, and the optical signal that reflective probe returns is given
Photodetector converts optical signals to weak current analog signal, exports to Date Conversion Unit, obtains tested gas concentration
Value.
Further, the Date Conversion Unit includes sequentially connected amplifier, analog-digital converter, controller, digital-to-analogue
Converter and current source, the amplifier connect photodetector, the current source connecting laser.
Further, the controller exports control signal and data signal to digital analog converter, makes digital analog converter
Periodic voltage analog signal is exported, in each period, voltage analog signal is divided into 2 stages：First stage, voltage value
For lower steady state value；Second stage, voltage value is zig-zag, and starting voltage is apparently higher than the constant electricity of first stage
Pressure.
Further, the voltage analog signal of digital analog converter is converted to current analog signal by current source, and driving swashs
Light device, for laser under the excitation of current source, output wavelength and light intensity are transferred to annular with the optical signal of drive current variations
Device.
Further, photodetector converts optical signals 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, output turns to analog-digital converter, modulus
Analog voltage signal is converted to digital signal by parallel operation, is exported to controller.
Further, after controller receives digital signal, within each period, first with the number of first stage
Amount, compensates the digital quantity of second stage, then calculates number when second stage digital quantity and tested gas concentration are zero
The difference of word amount finally calculates according to difference size and is tested gas concentration value.
Further, the laser is connected with temperature controller, keeps the temperature of laser constant.
Further, there are three ports, first port to receive the optical signal of laser for the circulator；Second port is by
The optical signal of Single port is transferred to reflective probe by optical fiber, and gives the optical signal transmission that reflective probe returns to third end
Mouthful, third port is by optical fiber output optical signal to photodetector.
Real-time mode as one preferred, the working method based on above-mentioned apparatus, includes the following steps：
(1) laser is under the action of driving current, the optical signal of output intensity and wavelength period variation；
(2) in open light path, optical signal interacts with tested gas；
(3) when the tested gas concentration of measurement is zero, the return light intensity of the second stage in each period；For various concentration
Tested gaseous sample, measure the return light intensity of the first stage in each period, and the second stage in each period
Return to light intensity；
(4) relatively it is tested the quilt of the return light intensity and various concentration of the second stage in each period when gas concentration is zero
The return light intensity of the second stage in gas each period is surveyed, the maximum place of difference is determined as optical wavelength and is narrowly focused towards tested gas
At the time of body absorption line centre wavelength, determine that optical wavelength alignment is tested gas absorption spectrum line centre wavelength optical signal and is tested
The linear relation of light intensity and tested gas concentration after gas interaction；
(5) light-intensity variation is compensated, calculates concentration calibration optical signal and the light after the interaction of tested gas
Intensity values obtain accurately being tested gas concentration value.
Further, in the step (1), it is utilized respectively the first stage in each period constant light intensity value and second-order
Section initial light intensity value, indicates the optical signal of laser, obtains light intensity variation range.
Further, in the step (2), in the opening light path of probe, optical signal interacts with tested gas, quilt
The concentration of survey gas and the relationship of light intensity are：In the first stage in each period, the wavelength of laser is far from tested gas
Absorption line, the variation of light intensity at this time and tested gas concentration are not related；In the second stage in each period, laser
Wavelength scanning range covering is tested the absorption line of gas, and when optical wavelength is directed at the centre wavelength of absorption line, light intensity declines
Decrement is in a linear relationship with tested gas concentration.
Further, in the step (3), when the tested gas concentration of measurement is zero, the second stage in each period
Light intensity is returned to, the digital quantity of record is the one-dimension array of a saw tooth wave shape, is denoted asFor the tested of various concentration
Gaseous sample measures the return light intensity for the first stage for obtaining each period, is denoted as I01；And second rank in each period
The return light intensity of section, is denoted asCompare two one-dimension arraysWithThe maximum place of difference is optical wavelength
It is corresponding at the time of being narrowly focused towards tested gas absorption spectrum line centre wavelengthValue in array is exactly optical wavelength alignment quilt
Survey gas absorption spectrum line centre wavelength optical signal and the light intensity value I after the interaction of tested gasC, according to multiple tested gases
I when normal concentrationCValue, obtains ICWith the linear relation of tested gas concentration C.
In the step (5), the return light intensity of the first stage in each period is measured, I is denoted as02, measure each period
Second stage return light intensity, record deviates the farthest light intensity value of zig-zag, is denoted as IC2, due to I02And IC2From complete
Consistent photosignal link, the Random Effect being subject to is identical, therefore has：
Light-intensity variation is compensated with this, after optical signal when calculating concentration calibration interacts with tested gas
Light intensity value obtains final tested gas concentration value.
Compared with prior art, the beneficial effects of the utility model are：
The utility model utilizes wavelength agile technology, and the light intensity variation by each period and wavelength change are divided into two ranks
Section：First stage, absorption line of the optical wavelength far from tested gas, the at this time variation of light intensity are not closed with tested gas concentration
System；Second stage, the covering of optical wavelength scanning range are tested the absorption line of gas, the attenuation of light intensity and tested gas concentration
It is in a linear relationship；Using the variable quantity of first stage light intensity, the variable quantity of second stage light intensity is compensated, the work(of light source is eliminated
Optical signal caused by the enchancement factors such as the variation of couple state, the drift of photoelectric device index at rate drift, optical signal link couples
Then the random variation of intensity calculates according to linear relationship and is tested gas concentration, improves measurement accuracy and long-time stability.
Description of the drawings
The accompanying drawings which form a part of this application are used for providing further understanding of the present application, and the application's shows
Meaning property embodiment and its explanation do not constitute the improper restriction to the application for explaining the application.
Fig. 1 is structure drawing of device；
Fig. 2 is voltage analog signal oscillogram；
Fig. 3 is laser output intensity figure；
Fig. 4 is return plot of light intensity when tested gas concentration is not zero.
Specific implementation mode：
The utility model is described in further detail with embodiment below in conjunction with the accompanying drawings.
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 implementation mode, 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 singulative
It is also 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 combination thereof.
In the present invention, term for example "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal",
The orientation or positional relationship of the instructions such as " side ", "bottom" is to be based on the orientation or positional relationship shown in the drawings, only to facilitate chatting
The relative for stating each component of the utility model or component structure relationship and determination, not refer in particular in the utility model either component or
Element should not be understood as limiting the present invention.
In the utility model, term such as " affixed ", " connected ", " connection " shall be understood in a broad sense, and expression can be fixed
Connection, can also be to be integrally connected or be detachably connected；It can be directly connected, the indirect phase of intermediary can also be passed through
Even.Related scientific research for this field or technical staff can determine above-mentioned term in the present invention as the case may be
Concrete meaning, should not be understood as limiting the present invention.
As background technology is introduced, what TDLAS technologies focused on solving in the prior art be optical source wavelength drift and by
Survey influence of the gas absorption spectrum line variation to accuracy of detection.And shape is coupled at the power stability of light source, optical signal link couples
The enchancement factors such as variation, the drift of photoelectric device index of state can equally cause the Strength Changes for being measured optical signal, seriously affect
The accuracy of measurement, in order to solve technical problem as above, present applicant proposes a kind of tunable semiconductors of wavelength agile to swash
Optical absorption spectra (TDLAS) gas-detecting device and method, the utility model utilize wavelength agile technology, compensate for the work(of light source
Optical signal caused by the enchancement factors such as the variation of couple state, the drift of photoelectric device index at rate drift, optical signal link couples
Strength Changes improve the precision and long-time stability of gas detection.
A kind of tunable diode laser absorption spectroscopy (TDLAS) gas-detecting device of wavelength agile, as shown in Figure 1,
Including：Controller, digital analog converter, current source, laser, temperature controller, circulator, reflective probe, photodetector, amplification
Device, analog-digital converter.Controller, analog-digital converter, current source, laser, circulator are sequentially connected；Temperature controller connects laser
Device controls the temperature of laser；Circulator is connected with reflective probe by optical fiber；Circulator, photodetector, amplifier,
Analog-digital converter, controller are sequentially connected.
Controller exports control signal and data signal to digital analog converter, and digital analog converter is made to export periodic voltage
Analog signal.In each period, voltage analog signal is divided into 2 stages：First stage, voltage value are lower steady state value；
Second stage, voltage value is zig-zag, and starting voltage is apparently higher than the constant voltage of first stage, as shown in Figure 2.
The voltage analog signal of digital analog converter is converted to current analog signal by current source, for driving laser.
For laser under the excitation of current source, output wavelength and light intensity are transferred to ring with the optical signal of drive current variations
Shape device, as shown in Figure 3.
Temperature controller keeps the temperature of laser constant.
Circulator has 3 ports.Port 1 receives the optical signal of laser；The optical signal of port 1 is passed through optical fiber by port 2
It is transferred to reflective probe, and the optical signal transmission that reflective probe is returned is to port 3；Believed by optical fiber output light port 3
Number give photodetector.
Reflective opening light path of the probe containing one section of fixed range realizes the interaction of optical signal and tested gas.
Photodetector converts optical signals to weak current analog signal, exports to amplifier.
Weak current analog signal is converted to voltage analog signal by amplifier, and line amplitude of going forward side by side amplification is exported to modulus
Converter.
Analog voltage signal is converted to digital signal by analog-digital converter, is exported to controller.
After controller receives digital signal, within each period, first with the digital quantity of first stage, to second-order
The digital quantity of section compensates, and then calculates the difference of digital quantity when second stage digital quantity and tested gas concentration are zero,
It is finally calculated according to difference size and is tested gas concentration value.
Based on above-mentioned apparatus, gas is tested by taking inflammable and explosive methane gas as an example, methane gas is obtained using following methods
The concentration value of body：
The first step：The generation of periodicity light signal
Laser is under the action of driving current, the optical signal of output intensity and wavelength period variation：
Wherein, I (t) indicates the light intensity signal of laser output；T indicates the time；T indicates the period；Δ T indicates each period
The time span of middle second stage, and Δ T ＜ T；K is integer, and k=0,1,2,3 ...；
Wherein, λ (t) indicates the optical wavelength of laser output.
Also, when the wavelength of optical signal is 1645.0nm, the absorption line far from methane gas, light intensity is not by methane gas
Concentration influences；When the wavelength of optical signal is 1645.5nm, the absorption line of close methane gas, and the range of 0.2nm wavelength
It is sufficiently large so that when optical source wavelength drifts about or methane gas absorption line is influenced by temperature, pressure and generates drift,
1645.5~1645.7nm can cover the absorption line of methane gas always.
Second step：The interaction of optical signal and methane gas
In the opening light path of probe, optical signal interacts with methane gas：
Wherein, ICIndicate optical signal and the light intensity after methane gas interaction；IinIt indicates entry into before open light path
Light signal strength；Indicate the absorption coefficient in methane gas absorption line central wavelength；L indicates the effective of open light path
Light path；C indicates concentration of methane gas；λ=λCThe premise that expression 2-3 is set up is that optical wavelength is exactly equal to methane gas absorption
Core wavelength.
Under normal conditions, it just needs to alarm when concentration of methane gas is very low.Therefore, gas detection is generally concerned only with low dense
The measurement of angle value.
When concentration of methane gas is relatively low, formula 2-3 can be reduced to：
Obtaining concentration of methane gas is：
In the first stage in each period, absorption line of the wavelength far from methane gas of laser, light intensity at this time
Variation is not related with concentration of methane gas；First is covered in the wavelength scanning range of the second stage in each period, laser
The absorption line of alkane gas, when optical wavelength is directed at the centre wavelength of absorption line, the attenuation and concentration of methane gas of light intensity
It is in a linear relationship.
Third walks：Concentration calibration
In laboratory environments, when measurement concentration of methane gas is zero first, the return of the second stage in each period
Light intensity, the digital quantity of record are the one-dimension arrays of a saw tooth wave shape, are denoted asThen it is directed to the methane of various concentration
Gaseous sample measures the return light intensity for the first stage for obtaining each period, is a constant, is denoted as I01；And each week
The return light intensity of the second stage of phase and an array, are denoted asCompare two one-dimension arraysWithIt is corresponding at the time of the maximum place of difference is exactly that optical wavelength is narrowly focused towards methane gas absorption line centre wavelengthValue in array is exactly the I in formula 2-5CValue, as shown in Figure 4.I when according to multiple methane gas normal concentrationsCValue,
It can obtain ICWith the linear relation of concentration of methane gas C.
4th step：Light-intensity variation compensates
At the power excursion of light source, optical signal link couples the variation of couple state, photoelectric device index drift etc. with
When random variation occurs for light signal strength caused by machine factor, return to light intensity and will produce variation, at this time according to concentration calibration when obtain
To linear relation will produce error to calculate concentration of methane gas.Therefore, it is necessary to be compensated to light-intensity variation.
When practical measurement, the return light intensity of the first stage in each period is measured first, is denoted as I02；Then it measures each
The return light intensity of the second stage in period, record deviate the farthest light intensity value of zig-zag, are denoted as IC2.Due to I02And IC2It comes from
Completely the same photosignal link, the Random Effect being subject to is identical, therefore has：
Can be by formula 2-6, and measure obtained IC2, light-intensity variation is compensated, when calculating concentration calibration
IC, to obtain very accurate concentration of methane gas value.
The foregoing is merely the preferred embodiments of the application, are not intended to limit this application, for the skill of this field
For art personnel, the application can have various modifications and variations.Within the spirit and principles of this application, any made by repair
Change, equivalent replacement, improvement etc., should be included within the protection domain of the application.
It is above-mentioned although specific embodiments of the present invention are described with reference to the accompanying drawings, but not to this practicality newly
The limitation of type protection domain, those skilled in the art should understand that, based on the technical solution of the present invention, ability
Field technique personnel need not make the creative labor the various modifications or changes that can be made still in the protection model of the utility model
Within enclosing.
Claims (4)
1. a kind of tunable diode laser absorption spectroscopy gas-detecting device of wavelength agile, it is characterized in that：Including laser,
Circulator, reflective probe, photodetector and Date Conversion Unit, wherein：
Output wavelength and light intensity are transferred to circulator, ring with the optical signal of drive current variations when the laser is activated
Shape device receives the optical signal of laser, and gives the optical signal transmission to reflective probe, reflective probe containing one section it is fixed away from
From opening light path, realize optical signal and tested gas interaction, and by it is reflective probe return optical signal to photoelectricity
Detector converts optical signals to weak current analog signal, exports to Date Conversion Unit, obtains tested gas concentration value.
2. a kind of tunable diode laser absorption spectroscopy gas-detecting device of wavelength agile as described in claim 1,
It is characterized in：The Date Conversion Unit includes sequentially connected amplifier, analog-digital converter, controller, digital analog converter and electricity
Stream source, the amplifier connect photodetector, the current source connecting laser.
3. a kind of tunable diode laser absorption spectroscopy gas-detecting device of wavelength agile as described in claim 1,
It is characterized in：The laser is connected with temperature controller, keeps the temperature of laser constant.
4. a kind of tunable diode laser absorption spectroscopy gas-detecting device of wavelength agile as described in claim 1,
It is characterized in：There are three port, first ports to receive the optical signal of laser for the circulator；Second port is by the light of first port
Signal is transferred to reflective probe by optical fiber, and the optical signal transmission that reflective probe is returned is to third port, third end
Mouth is by optical fiber output optical signal to photodetector.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721633127.2U CN207636485U (en) | 2017-11-29 | 2017-11-29 | The tunable diode laser absorption spectroscopy gas-detecting device of wavelength agile |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721633127.2U CN207636485U (en) | 2017-11-29 | 2017-11-29 | The tunable diode laser absorption spectroscopy gas-detecting device of wavelength agile |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN207636485U true CN207636485U (en) | 2018-07-20 |
Family
ID=62854840
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201721633127.2U Active CN207636485U (en) | 2017-11-29 | 2017-11-29 | The tunable diode laser absorption spectroscopy gas-detecting device of wavelength agile |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN207636485U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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 |
| CN110987867A (en) * | 2018-10-02 | 2020-04-10 | 阿克塞特里斯股份公司 | Method and system for relative positioning of target gases in an optical measurement system for laser spectroscopy |
-
2017
- 2017-11-29 CN CN201721633127.2U patent/CN207636485U/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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 |
| CN110987867A (en) * | 2018-10-02 | 2020-04-10 | 阿克塞特里斯股份公司 | Method and system for relative positioning of target gases in an optical measurement system for laser spectroscopy |
| CN110987867B (en) * | 2018-10-02 | 2022-09-30 | 阿克塞特里斯股份公司 | Method and system for relative positioning of target gases in an optical measurement system for laser spectroscopy |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9091151B2 (en) | Downhole optical radiometry tool | |
| CN103499545B (en) | Semiconductor Laser Gas Detection System Using Gas Reference Cavity Feedback Compensation | |
| US20110188042A1 (en) | Self referencing led detection system for spectroscopy applications | |
| CN102353633B (en) | Flue gas content laser on-line detection method and system | |
| CN108692812B (en) | Black body cavity spectral absorption rate measuring device and method | |
| CN108801977B (en) | Uncalibrated trace carbon 12 and carbon 13 carbon dioxide gas detection device and method | |
| CN102183308B (en) | Method for measuring wavelength variation of tunable laser | |
| RU102256U1 (en) | DEVICE FOR MEASURING PHYSICAL FIELD PARAMETERS | |
| CN113916802A (en) | Automatic calibration open-circuit type laser gas detection device and implementation method | |
| CN203414177U (en) | Optical fiber scanning light source wavelength calibration device based on gas absorption lines | |
| CN207636485U (en) | The tunable diode laser absorption spectroscopy gas-detecting device of wavelength agile | |
| Yang et al. | A methane telemetry sensor based on near-infrared laser absorption spectroscopy | |
| CN107991267A (en) | The tunable diode laser absorption spectroscopy gas-detecting device and method of wavelength agile | |
| CN102207458A (en) | Signal demodulation method for fiber grating-based near-infrared absorption type concentration sensor | |
| CN106323915A (en) | Device based on optical fiber M-Z interferometer to detect hydrogen sulfide gas | |
| Chen et al. | An auto-correction laser photoacoustic spectrometer based on 2 f/1 f wavelength modulation spectroscopy | |
| CN109270027A (en) | A kind of gas absorptivity On-line Measuring Method based on the fitting of Sine Modulated time domain | |
| Wang et al. | Gas concentration sensing based on fiber loop ring-down spectroscopy: a review | |
| CN101710068B (en) | Fiber gas sensor based on Fourier transform spectrometry | |
| CN101900575A (en) | An optical sensor based on an active resonant cavity and a cascaded passive resonant cavity | |
| Sardesai et al. | Versatile common instrumentation for optical detection of pH and dissolved oxygen | |
| CN110057779A (en) | Method and apparatus based on temperature self-compensation TDLAS technology measurement gas concentration | |
| RU2608394C1 (en) | Device for measuring parameters of physical fields | |
| Wang et al. | Detection of gas concentration by correlation spectroscopy using a multi-wavelength fiber laser | |
| RU92180U1 (en) | DEVICE FOR MEASURING PHYSICAL FIELD PARAMETERS |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |