CN119935954A - Gas detection device and method based on V-type wavelength tuning and modulation technology - Google Patents
Gas detection device and method based on V-type wavelength tuning and modulation technology Download PDFInfo
- Publication number
- CN119935954A CN119935954A CN202510109598.6A CN202510109598A CN119935954A CN 119935954 A CN119935954 A CN 119935954A CN 202510109598 A CN202510109598 A CN 202510109598A CN 119935954 A CN119935954 A CN 119935954A
- Authority
- CN
- China
- Prior art keywords
- signal
- channel
- algorithm
- output
- mirror
- 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.)
- Granted
Links
Landscapes
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
The invention discloses a gas detection device based on V-shaped wavelength tuning and modulation technology, which comprises a V-shaped waveform modulator, a tunable laser, a parabolic mirror, a gas sample cell, a half-reflecting half-lens, an etalon, a total reflection mirror, a double-channel photoelectric detector, a signal demodulation and analysis module and a signal display and output module which are sequentially connected in series. The invention also discloses a gas detection method based on the V-shaped wavelength tuning and modulation technology. The invention utilizes the dependence characteristic of the output power and wavelength of the tunable semiconductor laser on the scanning current or voltage, combines the symmetry of the V-shaped waveform, realizes the wavelength scanning and modulation of the laser in an ultra-narrow range, and can effectively reduce the influence of the nonlinear effect of the laser in spectral signal processing and concentration inversion. Compared with the traditional wide-range wavelength scanning and modulation mode, the invention has the advantages of high response speed, high stability and measurement precision, more compact overall structure and higher general practicability in practical application.
Description
Technical Field
The invention relates to the technical field of laser spectrum and gas detection, in particular to a gas detection device and method based on V-shaped wavelength tuning and modulation technology.
Background
The direct absorption spectrum technology is a spectrum analysis technology based on Lambert-Beer law, and can directly calculate parameter information such as concentration of gas to be analyzed by measuring light intensity of incident laser before and after passing through a gas absorption medium and combining known molecular spectral line parameters and experimental condition parameters (such as temperature, pressure and optical path) and spectrum linear functions. However, the physical quantity obtained by analyzing the light intensity variation in the direct absorption spectroscopy technique is absorbance representing the intensity of absorption of molecules, and is affected by various noises, and the detection sensitivity thereof is usually on the order of 10 -3. Aiming at the 1/f dependence characteristic of typical noise, the developed wavelength modulation spectrum technology has a good noise suppression effect in combination with a phase-locked demodulation principle, so that higher sensitivity can be realized, and the technology principle is mainly divided into a fixed wavelength modulation spectrum and a scanning wavelength modulation spectrum. The fixed wavelength modulation spectroscopy is characterized in that the output wavelength of a laser is fixed at the absorption spectrum line of a gas molecule to be measured, the gas absorption signal under the specific wavelength is directly measured, the implementation process is relatively simple, but in practical application, although the output wavelength of the laser can be regulated and controlled through feedback, the long-time stability is difficult to ensure, and the accuracy of a measurement result is further influenced. In contrast, the scanning wavelength modulation spectrum obtains full spectrum information of a molecular absorption signal by tuning the output wavelength of the laser, and the center position of the scanning wavelength modulation spectrum can be monitored and corrected in real time in the signal processing process, so that a measurement result has higher accuracy and is widely applied. However, tunable semiconductor lasers commonly used in wavelength modulation spectroscopy have significant dependence of the emission wavelength and output power on their operating current or voltage, and as the tuning current or voltage range increases, nonlinear effects of the emission wavelength and output power become more pronounced, thereby inducing so-called residual amplitude effects. Existing studies have shown that these effects have a non-negligible effect on wavelength modulation spectroscopy to detect trace gas concentrations. In addition, the wavelength modulation spectrum is used as an indirect analysis technology, the concentration inversion can be carried out on the measurement signal after the system is established to establish a correction model, and the reliability of the correction model is easily influenced by the long-term stability of the spectrum system.
Disclosure of Invention
The invention aims to provide a gas detection device and a method based on V-shaped wavelength tuning and modulation technology, so as to solve the defects.
In order to achieve the above object, the present invention provides the following technical solutions:
A gas detection device based on V-shaped wavelength tuning and modulation technology comprises a V-shaped waveform modulator, a tunable laser, a parabolic mirror, a gas sample cell, a half-reflecting half-lens, an etalon, a total-reflecting mirror, a double-channel photoelectric detector, a signal demodulation and analysis module and a signal display and output module which are sequentially connected in series, wherein V-shaped voltage or current waveform signals output by the V-shaped waveform modulator are input to the tunable laser to output laser beams, focused and reflected by the parabolic mirror and then directly coupled into the gas sample cell, reflected beams passing through the half-reflecting half-lens and beams passing through the half-reflecting half-lens, the etalon to be transmitted and the total-reflecting half-reflecting mirror are input to the double-channel photoelectric detector, demodulated and analyzed by the signal demodulation and analysis module, and finally input to the signal display and output module to be displayed and output.
Preferably, the half-reflecting and half-reflecting lens divides the incident light beam into two vertical light beams, namely a reflected light beam and a transmitted light beam, wherein the reflected light beam passing through the half-reflecting mirror is directly reflected to the two-channel photoelectric detector and marked as a first channel signal, and the transmitted light beam passing through the half-reflecting mirror is transmitted through the etalon and is reflected to the two-channel photoelectric detector through the total reflecting mirror and marked as a second channel signal.
Preferably, the signal demodulation and analysis module comprises a signal demodulation module and a signal analysis module, wherein the signal demodulation module demodulates the first channel signal into a second harmonic signal with gas absorption by combining the V-shaped waveform modulation signal output by the V-shaped waveform modulator (1), and then the second harmonic signal and the interference signal of the etalon (6) in the second channel are simultaneously transmitted to the signal analysis module for analysis and treatment.
Preferably, the signal analysis module performs analysis processing by adopting a method comprising a spectrum signal center position correction algorithm, a signal filtering denoising and signal averaging algorithm, a wavelength correction algorithm and a concentration inversion algorithm.
Preferably, the signal display and output module comprises an LCD liquid crystal display unit and a signal output unit, wherein the signal output unit has a Bluetooth wireless communication output function and a wired serial port communication output and network port communication output interface.
Preferably, the spectral signal center position correction algorithm, the signal filtering denoising and the signal averaging algorithm are as follows:
The method comprises the steps of firstly, primarily estimating a minimum value position P of a second harmonic signal acquired by a first channel, secondly, selecting data sets D (P-10, P+10) of about 10 point ranges near the minimum value position P, smoothly filtering the data sets D (P-10, P+10), then, solving the accurate minimum value position P of the filtered data sets, carrying out similar correction and filtering processing on each measuring signal by taking the accurate minimum value position P as the optimal center position, and finally, carrying out average processing on all signals of the first channel according to defined signal average times to acquire an original spectrum signal with higher signal to noise ratio.
Preferably, the wavelength correction algorithm is specifically as follows:
The method is used for the interference signal analysis processing of the etalon (6), the positions corresponding to the peaks in the interference fringe signals are calculated firstly, then the positions of the peaks are used as the abscissa, an integral array [1,2, ], which is established by the total number N of the peaks, is used as the ordinate, a corresponding curve is established, a polynomial fitting formula is obtained by carrying out higher-order polynomial fitting on the corresponding curve, then the integral array [1,2, ], which is corresponding to the total number N of the peaks, is used as the independent variable, the independent variable is substituted into the obtained polynomial fitting formula, and the free spectral region FSR value of the etalon is multiplied, so that the relative wave number range of the laser emission wavelength can be calculated. And finally, calculating the difference between the relative wave number and the absolute wave number by combining the relative central position of the gas molecule absorption spectrum to be analyzed when the relative wave number is the abscissa and the absolute position of the corresponding spectral line in the database, and adding the difference and the relative wave number, thereby realizing wave number correction of the wavelength tuning range of the laser.
Preferably, the concentration inversion algorithm comprises two methods, namely a multidimensional linear regression algorithm and a linear fitting algorithm, and the method comprises the following specific steps:
the multidimensional linear regression algorithm is characterized in that the number of sampling points of a spectrum signal is assumed to be n, n is a natural number, a measuring signal is Amb, a background signal is Bgr, a calibrated signal after background correction is Cal, the concentration of gas to be analyzed is c, a solving function is defined as xi, and a specific expression is shown as follows:
the concentration inversion calculation process combines a multidimensional linear regression algorithm and a least mean square algorithm, the algorithm calculation process obtains an optimal c value by solving the minimum value of a function xi, and the combination differential calculation formula is as follows:
The linear fitting algorithm adopts a hard collision linear type H (x, y) and a soft collision linear type G (x, y, z) aiming at different molecular characteristics, and theoretical expressions of the linear fitting algorithm can be respectively described by the following function models:
Wherein: M is a confluent super-geometric function, D is Dicke narrowing coefficients and eta is an optical diffusion coefficient, pi represents a circumference ratio, S represents spectral line intensity, w (u) represents a complex function related to a variable u, i represents complex imaginary units, and gamma D and gamma L represent Doppler line width and Lorentz line width respectively.
Using the two linear functions above, the calculation was fitted by integrating the area a of the absorption signal in the molecular absorption spectrum:
wherein, alpha (v) represents an absorption coefficient, L represents an absorption optical path, v represents an integral variable wave number, v 0 represents a molecular spectral line center wave number, S (T) represents a spectral line intensity related to temperature T, and N (T, P) represents a molecular number related to temperature T and pressure P.
The combination of the linear function meets the normalization condition, and the method can be simplified as follows:
A=S(T)·N·L,
Wherein S (T) and L are as defined above, and N represents the number of molecules of the absorption medium to be detected.
Finally, under the condition of the related experimental conditions including known temperature T, pressure P, optical path L and molecular spectral line intensity S to be detected, the molecular number or concentration of the absorbed molecules can be inversed by fitting the calculated molecular integral absorption area A, and on the contrary, the spectral line parameters of the molecules can be calculated.
Preferably, a gas detection method based on V-type wavelength tuning and modulation technology comprises the following steps:
S1, adjusting and outputting a V-shaped voltage or current waveform signal according to a load working parameter through a V-shaped waveform modulator 1, inputting the V-shaped voltage or current waveform signal into a tunable laser 2, and driving the tunable laser 2 to output a laser beam in a certain wavelength range;
S2, the output laser beam is focused and reflected by the parabolic mirror 3, the reflected beam is directly coupled into the gas sample cell 4, the mutual absorption process is carried out between the gas sample cell 4 and a gas medium to be detected, and finally the beam is emitted;
S3, the emitted light beam is reflected and transmitted through the half-reflecting and half-reflecting mirror 5, the reflected light beam through the half-reflecting mirror 5 is directly reflected to the double-channel photoelectric detector 8 and marked as a first channel signal, the transmitted light beam through the half-reflecting mirror 5 is transmitted through the etalon 6 to generate an interference signal for laser output wavelength correction, and finally the interference signal is incident into the total reflecting mirror 7 and reflected to the double-channel photoelectric detector 8 and marked as a second channel signal;
S4, the light beam signals marked by the double-channel photoelectric detector 8 are input into the signal demodulation and analysis module 9, the demodulation module is used for demodulating the first channel signals into second harmonic signals with gas absorption by combining the V-shaped waveform modulation signals output by the V-shaped waveform modulator 1, and the second harmonic signals and interference signals of the second channel etalon 6 are simultaneously transmitted to the signal analysis module for analysis;
S5, inputting the analyzed gas concentration signal subjected to the analysis processing into the signal display and output module 10 for display and output, so that gas detection based on the V-shaped wavelength tuning and modulation technology is realized.
The invention has the beneficial effects that:
(1) The gas detection device and the method based on the V-shaped wavelength tuning and modulation technology not only improve the response time of a system and effectively reduce the influence of nonlinear effect of the laser on a spectrum signal by driving the tunable semiconductor laser through the ultra-narrow-range V-shaped wave signal, but also effectively solve the signal distortion phenomenon after spectrum averaging caused by the drift of the center wavelength of the laser by adopting a center position correction algorithm, a signal filtering denoising and a signal averaging algorithm through a signal demodulation and analysis module, and effectively improve the measurement precision and accuracy of a measurement result by adopting a multidimensional linear regression algorithm and a least mean square algorithm to analyze the concentration of the spectrum signal.
(2) The gas detection device and method based on the V-shaped wavelength tuning and modulation technology, disclosed by the invention, utilize the dependence characteristic of the output power and wavelength of the tunable semiconductor laser on the scanning current or voltage, combine the symmetry of the V-shaped waveform, realize the wavelength scanning and modulation of the laser in an ultra-narrow range, and can effectively reduce the influence of the nonlinear effect of the laser in spectral signal processing and concentration inversion. Compared with the traditional wide-range wavelength scanning and modulation mode, the invention has the advantages of high response speed, high stability and measurement precision, more compact overall structure and higher general practicability in practical application.
Drawings
FIG. 1 is a structural frame diagram of a gas detection device based on V-type wavelength tuning and modulation technique of the present invention;
FIG. 2 is a graph of nonlinear effects of typical tunable semiconductor laser emission spectral range and drive voltage;
FIG. 3 is a diagram showing the comparison of a conventional ramp wave with a V-shaped scan modulation signal and its corresponding second harmonic signal;
FIG. 4 is a plot of the etalon interference signal and peak position calibration of the present invention;
FIG. 5 is a schematic diagram of a concentration inversion flow based on a multidimensional linear regression algorithm and a least mean square algorithm of the present invention;
fig. 6 is a schematic diagram of an integral area affit based on a linear fitting algorithm according to the present invention.
Detailed Description
The invention is further described below with reference to examples, which are merely illustrative and explanatory of the principles of the invention, and various modifications and additions may be made to the described embodiments by those skilled in the art, or similar thereto, without departing from the spirit of the invention or beyond the scope of the appended claims.
Example 1:
Fig. 1 is a structural frame diagram of a gas detection device based on V-type wavelength tuning and modulation techniques. As shown in fig. 1, the gas detection device based on the V-shaped wavelength tuning and modulation technology comprises a V-shaped waveform modulator 1, a tunable laser 2, a parabolic mirror 3, a gas sample cell 4, a half-reflecting half-lens 5, an etalon 6, a full-reflecting mirror 7, a double-channel photoelectric detector 8, a signal demodulation and analysis module 9 and a signal display and output module 10 which are sequentially connected in series.
The V-shaped waveform modulator 1 adjusts and outputs a V-shaped voltage or current waveform signal according to the load operation parameters.
And a tunable laser 2, wherein a V-shaped voltage or current waveform signal output by the V-shaped waveform modulator 1 is input into the tunable laser 2, and the tunable laser 2 is driven to output a laser beam within a certain wavelength range.
The parabolic mirror 3 is capable of focusing and reflecting the laser beam output from the tunable laser 2.
The gas sample cell 4 contains a gas medium to be detected. The reflected light beam of the parabolic mirror 3 is directly coupled into the gas sample cell 4, and the mutual absorption process occurs between the gas sample cell 4 and the gas medium to be detected, and finally the light beam is emitted.
The half-reflecting half-lens 5 divides the incident light beam into two perpendicular light beams, a reflected light beam and a transmitted light beam. The reflected light beam passing through the half mirror 5 is directly reflected to the double-channel photodetector 8 and marked as a first channel signal, while the transmitted light beam passing through the half mirror 5 is transmitted through the etalon 6 and reflected by the total reflection mirror 7 and then input to the double-channel photodetector 8 and marked as a second channel signal.
The demodulation and analysis module 9 comprises a signal demodulation module and a signal analysis module, wherein the signal demodulation module demodulates the first channel signal into a second harmonic signal with gas absorption by combining the V-shaped waveform modulation signal output by the V-shaped waveform modulator 1, and then the second harmonic signal and the interference signal of the etalon 6 in the second channel are simultaneously transmitted to the signal analysis module for analysis and processing.
The signal display and output module 10 comprises an LCD liquid crystal display unit and a signal output unit, wherein the signal output unit has a Bluetooth wireless communication output function and a wired serial port communication output and network port communication output interface so as to meet the requirements of different display terminals. The gas concentration signal to be analyzed, which is subjected to demodulation and analysis processing by the signal demodulation and analysis module 9, is input into the signal display and output module 10 for display and output, so that gas detection based on V-shaped wavelength tuning and modulation technology is realized.
A gas detection method based on V-shaped wavelength tuning and modulation technology comprises the following steps:
S1, a V-shaped waveform modulator 1 is used for adjusting and outputting a V-shaped voltage or current waveform signal according to a load working parameter, and then the V-shaped voltage or current waveform signal is input into a tunable laser 2 to drive the tunable laser 2 to output a laser beam in a certain wavelength range.
In this example, a semiconductor laser having a center wavelength of about 6046.5cm -1 and a method of measuring methane gas molecules are described as an example. If the laser sources matched with other molecules are selected, the high-precision measurement and analysis of different gas components can be realized.
Fig. 2 is a graph of nonlinear effects of the spectral range of emission and drive voltage of a typical tunable semiconductor laser. As shown in fig. 2, the strong absorption spectrum characteristic of the methane (CH 4) molecule at 6046.5cm -1 exists, and the wavelength tuning characteristic of the semiconductor laser commonly used in this band has a significant nonlinear effect, such as polynomial fitting result in the figure.
Fig. 3 is a diagram showing a comparison between a conventional ramp wave and a V-waveform scan modulation signal and a corresponding second harmonic signal thereof, in which fig. 3 (a) is a diagram showing a conventional ramp wave scan modulation signal, fig. 3 (b) is a diagram showing a V-waveform scan modulation signal, fig. 3 (c) is a diagram showing a second harmonic signal corresponding to a conventional ramp wave, and fig. 3 (d) is a diagram showing a second harmonic signal corresponding to a V-waveform of the present invention. As shown in FIG. 3, the conventional ramp tuning and modulation mode requires about 1.0 point resolution to obtain the complete second harmonic signal spectrogram, while the V-waveform tuning and modulation mode provided by the invention only requires about 0.4 point resolution to obtain the complete second harmonic signal spectrogram.
S2, the output laser beam is focused and reflected by the parabolic mirror 3, the reflected beam is directly coupled into the gas sample cell 4, the mutual absorption process is carried out between the gas sample cell 4 and the gas medium to be detected, and finally the beam is emitted.
S3, the emitted light beam is reflected and transmitted through the half-reflecting and half-reflecting mirror 5, the reflected light beam through the half-reflecting mirror 5 is directly reflected to the double-channel photoelectric detector 8 and marked as a first channel signal, and the transmitted light beam through the half-reflecting mirror 5 is transmitted through the etalon 6 to generate an interference signal for laser output wavelength correction, and finally the interference signal is incident into the total reflecting mirror 7 and reflected to the double-channel photoelectric detector 8 and marked as a second channel signal.
S4, the light beam signals marked by the double-channel photoelectric detector 8 are input into the signal demodulation and analysis module 9, the first channel signals are demodulated by the demodulation module through combining with the V-shaped waveform modulation signals output by the V-shaped waveform modulator 1 to obtain second harmonic signals with gas absorption, and the second harmonic signals and the second channel signals are simultaneously transmitted to the signal analysis module for analysis and processing.
The signal analysis module performs analysis processing, and the adopted method comprises a spectrum signal center position correction algorithm, a signal filtering denoising and signal averaging algorithm, a wavelength correction algorithm and a concentration inversion algorithm.
The spectrum signal center position correction algorithm, the signal filtering denoising and signal averaging algorithm comprise the following steps of firstly, primarily estimating a minimum value position P of a second harmonic signal acquired by a first channel, secondly, selecting data sets D (P-10, P+10) of about 10 point ranges near the minimum value position P, then carrying out smooth filtering on the data sets D (P-10, P+10), then solving the accurate minimum value position P of the filtered data sets, carrying out similar correction and filtering processing on each measuring signal by taking the accurate minimum value position P as the optimal center position, and finally, carrying out average processing on all signals in the first channel according to defined signal average times so as to acquire an original spectrum signal with higher signal to noise ratio.
The wavelength correction algorithm is mainly used for analysis and processing of interference signals of the etalon (6) in the second channel signal. FIG. 4 is a plot of the etalon interference signal and peak position calibration of the present invention. As shown in fig. 4, the wavelength correction algorithm is specifically as follows:
The relative wave number range of the laser can be calculated by firstly calculating the position corresponding to each Peak value (Peak) in the interference fringe signal, then taking the Peak value position as an abscissa, taking an integral sequence [1,2, ], N ] established by the total number N of Peak values as an ordinate, establishing a corresponding curve and carrying out higher-order polynomial fitting on the corresponding curve to obtain a polynomial fitting formula, then taking the integral sequence [1,2, ], N ] corresponding to the total number N of Peak values as an independent variable, substituting the independent variable into the obtained polynomial fitting formula, and multiplying the independent spectrum region FSR value of the etalon 6. And finally, calculating the difference between the relative wave number and the absolute wave number by combining the relative central position of the gas molecule absorption spectrum to be analyzed when the relative wave number is the abscissa and the absolute position of the corresponding spectral line in the database, and adding the difference and the relative wave number, thereby realizing wave number correction of the wavelength tuning range of the laser.
The concentration inversion algorithm mainly comprises a multidimensional linear regression algorithm and a linear fitting algorithm, and specifically comprises the following steps:
the multidimensional linear regression algorithm is characterized in that the number of sampling points of a spectrum signal is assumed to be n, n is a natural number, a measuring signal is Amb, a background signal is Bgr, a calibrated signal after background correction is Cal, the concentration of gas to be analyzed is c, a solving function is defined as xi, and a specific expression is shown as follows:
Fig. 5 is a schematic diagram of a concentration inversion flow based on a multidimensional linear regression algorithm and a least mean square algorithm, as shown in fig. 5, in a concentration inversion calculation process, in combination with the multidimensional linear regression algorithm and the least mean square algorithm, the algorithm calculation process obtains an optimal c value by solving a minimum value of a function ζ, and in combination with a differential calculation formula as follows:
The linear fitting algorithm adopts a hard collision linear type H (x, y) and a soft collision linear type G (x, y, z) aiming at different molecular characteristics, and theoretical expressions of the linear fitting algorithm can be respectively described by the following function models:
Wherein: M is a confluent super-geometric function, D is Dicke narrowing coefficients and eta is an optical diffusion coefficient, pi represents a circumference ratio, S represents spectral line intensity, w (u) represents a complex function related to a variable u, i represents complex imaginary units, and gamma D and gamma L represent Doppler line width and Lorentz line width respectively.
Using the two linear functions above, the calculation was fitted by integrating the area a of the absorption signal in the molecular absorption spectrum:
wherein, alpha (v) represents an absorption coefficient, L represents an absorption optical path, v represents an integral variable wave number, v 0 represents a molecular spectral line center wave number, S (T) represents a spectral line intensity related to temperature T, and N (T, P) represents a molecular number related to temperature T and pressure P.
The combination of the linear function meets the normalization condition, and the method can be simplified as follows:
A=S(T)·N·L,
Wherein S (T) and L are as defined above, and N represents the number of molecules of the absorption medium to be detected.
Finally, under the condition that relevant experimental conditions (such as parameters of temperature T, pressure P, optical path L, line intensity S of a molecule to be detected and the like) are known, the number or concentration of molecules to be absorbed can be inverted through the molecular integral absorption area A calculated through fitting, and on the contrary, the line parameters (such as line intensity) of the molecules can be calculated. Fig. 6 is a schematic diagram of fitting of an integral area a based on a linear fitting algorithm according to the present invention, as shown in fig. 6, the fitting residuals of two linear models are smaller than 8×10 -5, so that the linear models are very high in matching degree with experimental data, and high-precision concentration inversion can be achieved.
Finally, under the condition of the related experimental conditions including known temperature T, pressure P, optical path L and molecular spectral line intensity S to be detected, the molecular number or concentration of the absorbed molecules can be inversed by fitting the calculated molecular integral absorption area A, and on the contrary, the spectral line parameters of the molecules can be calculated.
S5, inputting the analyzed gas concentration signal subjected to the analysis processing into the signal display and output module 10 for display and output, so that gas detection based on the V-shaped wavelength tuning and modulation technology is realized.
The gas detection device and the method based on the V-shaped wavelength tuning and modulation technology not only improve the response time of a system and effectively reduce the influence of nonlinear effect of the laser on a spectrum signal by driving the tunable semiconductor laser through the ultra-narrow-range V-shaped wave signal, but also effectively solve the signal distortion phenomenon after spectrum averaging caused by the drift of the center wavelength of the laser by adopting a center position correction algorithm, a signal filtering denoising and a signal averaging algorithm through a signal demodulation and analysis module, and effectively improve the measurement precision and accuracy of a measurement result by adopting a multidimensional linear regression algorithm and a least mean square algorithm to analyze the concentration of the spectrum signal.
The gas detection device and method based on the V-shaped wavelength tuning and modulation technology, disclosed by the invention, utilize the dependence characteristic of the output power and wavelength of the tunable semiconductor laser on the scanning current or voltage, combine the symmetry of the V-shaped waveform, realize the wavelength scanning and modulation of the laser in an ultra-narrow range, and can effectively reduce the influence of the nonlinear effect of the laser in spectral signal processing and concentration inversion. Compared with the traditional wide-range wavelength scanning and modulation mode, the invention has the advantages of high response speed, high stability and measurement precision, more compact overall structure and higher general practicability in practical application.
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
Claims (9)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202510109598.6A CN119935954B (en) | 2025-01-23 | Gas detection device and method based on V-shaped wavelength tuning and modulation technology |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202510109598.6A CN119935954B (en) | 2025-01-23 | Gas detection device and method based on V-shaped wavelength tuning and modulation technology |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN119935954A true CN119935954A (en) | 2025-05-06 |
| CN119935954B CN119935954B (en) | 2025-10-17 |
Family
ID=
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0629851A2 (en) * | 1993-06-17 | 1994-12-21 | Fraunhofer-Gesellschaft Zur Förderung Der Angewandten Forschung E.V. | Device for the analysis of traces of gas with absorption spectroscopy |
| US20080128618A1 (en) * | 2006-09-27 | 2008-06-05 | Anis Rahman | Dendrimer Based Electro-Optic Sensor |
| CN105277503A (en) * | 2015-08-20 | 2016-01-27 | 安徽大学 | Multi-component gas simultaneous detection device and method based on two quantum cascade laser spectrums |
| CN218512308U (en) * | 2022-06-30 | 2023-02-21 | 武汉理工大学 | Gas concentration detection device based on multi-harmonic information fusion laser absorption spectroscopy technology |
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0629851A2 (en) * | 1993-06-17 | 1994-12-21 | Fraunhofer-Gesellschaft Zur Förderung Der Angewandten Forschung E.V. | Device for the analysis of traces of gas with absorption spectroscopy |
| US20080128618A1 (en) * | 2006-09-27 | 2008-06-05 | Anis Rahman | Dendrimer Based Electro-Optic Sensor |
| CN105277503A (en) * | 2015-08-20 | 2016-01-27 | 安徽大学 | Multi-component gas simultaneous detection device and method based on two quantum cascade laser spectrums |
| CN218512308U (en) * | 2022-06-30 | 2023-02-21 | 武汉理工大学 | Gas concentration detection device based on multi-harmonic information fusion laser absorption spectroscopy technology |
Non-Patent Citations (2)
| Title |
|---|
| JIAN SANG等: "Impact of H2O on atmospheric CH4 measurement in near-infrared absorption spectroscopy", 《SPECTROCHIMICA ACTA PART A: MOLECULAR AND BIOMOLECULAR SPECTROSCOPY》, vol. 237, 22 April 2020 (2020-04-22), pages 118383 * |
| 王敏等: "可调谐二极管激光吸收光谱二次谐波检测方法的研究", 光学技术, vol. 31, no. 02, 20 March 2005 (2005-03-20), pages 279 - 285 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113252204B (en) | Laser absorption spectrum temperature measurement method based on amplitude modulation | |
| CN109991189B (en) | Fixed point wavelength modulation gas concentration measuring device based on wave number drift correction and measuring method thereof | |
| CN104903703B (en) | Gas absorbs light-dividing device and gas absorbs light-splitting method | |
| CN111829982A (en) | Multi-component gas concentration detection and temperature error correction method | |
| CN104535530B (en) | High-precision gas concentration detection method and detection apparatus thereof | |
| CN204924934U (en) | Multi-component gas simultaneous detection device based on two quantum cascade laser spectrums | |
| CN107764761B (en) | Laser detection system and method for concentration of harmful gas in open space atmosphere | |
| CN107091818B (en) | Multi-gas-chamber complex component gas analysis system and method | |
| CN101617192A (en) | Wavelength modulation spectroscopy for simultaneous measurement of two or more gas components | |
| CN109696415B (en) | Gas absorption rate online measurement method based on fast Fourier transform | |
| CN111089661B (en) | Temperature rapid extraction method based on laser absorption spectrum | |
| CN101226147A (en) | A gas concentration quantitative analyzer | |
| CN109270027A (en) | A kind of gas absorptivity On-line Measuring Method based on the fitting of Sine Modulated time domain | |
| CN113447458A (en) | Gas temperature and concentration parameter measuring method based on laser absorption impedance spectroscopy | |
| CN114397273B (en) | Gas concentration measurement device and measurement method based on second-fourth harmonic combination | |
| CN107328738A (en) | The double air chamber trace gas analysis systems of one kind series connection and gas concentration calculate method | |
| CN112729544A (en) | Laser wavelength locking system and method for scanning absorption spectrum | |
| CN112666124A (en) | Absorption spectrum full-width half-maximum integral gas detection method for complex environment | |
| Li et al. | Fourier and wavelet transform analysis of wavelength modulation spectroscopy signal | |
| CN119334904A (en) | A tunable semiconductor laser spectral absorption method | |
| CN110907398A (en) | A kind of gas concentration measurement method and measurement device | |
| CN119935954B (en) | Gas detection device and method based on V-shaped wavelength tuning and modulation technology | |
| CN113533249A (en) | A N2O detection system and method based on open optical path and wavelength modulation | |
| CN119935954A (en) | Gas detection device and method based on V-type wavelength tuning and modulation technology | |
| CN118501092A (en) | Online detection method for water vapor concentration in high-purity nitrogen |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant |