CN112710628A - Ultra-sensitive SF (sulfur hexafluoride) based on broadband double-optical-comb spectrum6Gas decomposition component detection method - Google Patents
Ultra-sensitive SF (sulfur hexafluoride) based on broadband double-optical-comb spectrum6Gas decomposition component detection method Download PDFInfo
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Abstract
The invention provides an ultra-sensitive SF based on broadband double-optical-comb spectrum6The gas decomposition component detection system comprises two optical combs, a beam combiner, an enhanced gas sample pool, a lens, a hollow optical fiber, a microphone, an audio amplifier and a data acquisition card. The invention discloses an ultra-sensitive SF based on broadband double-optical-comb spectrum6The invention relates to a gas decomposition component detection method, which utilizes the characteristic of wide spectrum coverage of an optical comb and can realize simultaneous measurement of a plurality of molecular absorption peaks by a modulation mode of double-optical comb beat frequency, thereby solving the dilemma of point-by-point sweep frequency spectrum measurement of the traditional photoacoustic spectrum; the photoacoustic effect and the hollow optical fiber are combined, the effective optical path and the acting section of the interaction of light and molecules are increased, and the problem of low sensitivity of the traditional spectrum detection technology is solved; the technique is applied to SF6The detection of gas decomposition components can effectively improve the detection capability of the power equipment fault gas detection device on complex multi-component gas.
Description
Technical Field
The invention belongs to the technical field of gas detection, and particularly relates to ultra-sensitive SF (sulfur hexafluoride) based on broadband double-optical-comb spectrum6Gas decomposition component detection systems and methods.
Background
SF such as GIS (totally enclosed gas combined electrical appliance), open switch and mutual inductor6The (sulfur hexafluoride) gas insulation equipment is widely applied to electric power systems due to small occupied area and high reliability. Because all elements are sealed in the metal shell, early failure is more difficult to find than that of the conventional equipment, and even if the equipment is disassembled for maintenance, the equipment has complex process, the maintenance work is difficult and takes long time, so the loss caused by the failure is larger. Monitoring the internal states of GIS and other equipment, and avoiding accidents are always hot spots for research of domestic and foreign research institutions. By detecting SF in GIS equipment6The gas decomposition product can be used for fault diagnosis and state evaluation of the internal insulation of the equipment, has the characteristics of strong anti-interference capability, high sensitivity and the like, and is widely applied to on-site detection and analysis of the equipment. In actual GIS installations, SF6The gas contains trace amounts of impurities such as air, water and mineral oil, which participate in the reaction to form stable decomposition products, such as SO2、SOF2、H2S, HF, etc. Thus, by detecting SF6The volume fraction of the gas decomposition products is very helpful for discovering latent faults and fault location of the equipment.
The current gas detection means mainly include: contact technology (e.g., semiconductor sensors, contact combustion sensors, electrochemical sensors) and non-contact technology (e.g., Fourier transform infrared spectroscopy, spectral absorption). However, the current gas detection schemes suffer from the following problems:
1) the contact detection technology aims at single gas type, the type of the gas which can be monitored is very limited, and SF cannot be detected6The decomposed substances are comprehensively detected, so that single data error is introduced, and misjudgment is caused; the technology has the defects of fixed-point detection or manual field operation and the like; especially, the method aims at dangerous gas, has the problems of short service life and easy corrosion, and cannot realize online real-time monitoring.
2) The non-contact optical detection scheme mainly includes the following techniques.
a) Tunable semiconductor laser absorption spectroscopy (i.e., TDLAS) based on frequency modulation. The absorption spectrum is obtained by tuning the wavelength (or frequency) of the laser and detecting the transmitted light intensity transmitted through the absorption cell point by point. The gas cell with long optical path is combined, the measurement sensitivity is high, the precision is high, the resolution is high, but the measurement speed is extremely slow, the detection gas type is limited, and the cost is high.
b) Differential absorption spectroscopy (i.e., DOAS). The substance concentration measurement is achieved by using the differential absorption of light by the sample. Its advantages are simultaneous measurement of multiple trace gases, but its technique is limited to the gas molecules with narrow absorption line in the measured band, and its monitoring system is affected by water vapour in environment.
c) Photoacoustic spectroscopy (PAS). The photoacoustic spectroscopy detection system generally comprises a light source, a light modulator, a photoacoustic cell, a microphone, a demodulator, an audio amplifier and the like. The operation process is to use the light modulator to periodically modulate the intensity of the light source radiation. The modulated light then enters the photoacoustic cell to interact with the gas molecules. The molecules to be measured are excited to a high energy state after absorbing light energy, and radiate heat energy to the high energy state to generate sound waves of modulated frequency. At this time, the microphone receives the sound wave. The method can detect the concentration of the gas which has obvious absorption in the emission spectrum range of the infrared light source, and the selection of the spectrum range can be realized through the filter plate. The method has the disadvantages of low detection precision, low resolution and poor repeatability due to low coherence and stability of the infrared light source. In addition, it is difficult to achieve simultaneous measurement of the absorption peaks of the multi-component gases, which is also a drawback of this method.
An optical frequency comb (optical comb for short) is a broadband laser light source with good coherence and stable time-frequency characteristics. The spectrum detection technology based on the optical comb can realize simultaneous, high-precision and high-resolution measurement of hundreds of molecular absorption peaks. However, the method has low detection sensitivity due to wide optical comb spectrum and energy dispersion, and cannot be compared with the conventional gas detection technologies.
The spectrum detection technology has important application value in the aspects of troubleshooting, early warning and the like of the power equipment. However, since the components of the gas characteristic of the fault of the electrical equipment are complex and have different contents, strict requirements are imposed on the gas identification or resolution capability (selectivity), sensitivity, accuracy, and the properties of detectable gas types of the gas detection technology.
The existing non-contact gas detection technology has the problems of low spectral precision and accuracy, limited detection sensitivity, difficult quantitative analysis and limited information acquisition content. The problems greatly restrict the accuracy of the current gas detection and the real-time performance and reliability of the evaluation of the power transmission and transformation equipment.
Disclosure of Invention
The invention aims to provide a method for measuring the exciting light of the optical comb, which adopts an optical comb source as an exciting source, improves the time-frequency stability and coherence of exciting light, and further improves the precision and repeatability of measurement; realizing frequency modulation of a plurality of molecular absorption peaks through a multi-longitudinal-mode beat frequency effect of the double-optical comb, generating photoacoustic audio signals corresponding to the absorption peaks, and detecting the photoacoustic audio signals by a microphone; by means of binding laser and molecules in the hollow optical fiber, interaction cross sections of the molecules and the light are increased, molecular absorption strength is improved, and detection sensitivity of photoacoustic signals is improved6Gas decomposition component detection systems and methods.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
ultra-sensitive SF based on broadband double-optical-comb spectrum6A gas decomposition component detection system, the system comprising:
1) an optical comb light source: the optical comb light sources are two, and the carrier envelope phase zero frequency and the repetition frequency of the optical comb light sources are respectively as follows: f. of01And fr1And f02And fr2(ii) a Each optical comb is composed of n frequency teeth; wherein the frequency of the nth comb is f0+nfr. Frequency difference f of nth comb teeth of two optical combsb＝|(f02+nfr2)-(f01+nfr1) And then the beat frequency signals of the nth comb teeth of the two optical combs. By tuning the laser parameter, i.e. f0And frCan make the beat frequency signal fbIn the audio frequency domain (20Hz-20 kHz).
2) A beam combiner: for coupling the output light of the two optical combs into spatially coincident light beams.
3) Enhancement mode gas appearance pond: the enhanced gas sample cell comprises a gas inlet, a gas outlet, a light-transmitting window, a hollow optical fiber wound on a microphone, and a coupling lens for coupling laser into the optical fiber. The hollow optical fiber is an optical transmission medium in which an optical fiber is hollow to form a cylindrical space.
4) A microphone: for receiving an audio signal.
5) The audio amplifier: for amplifying weak signals.
6) A data acquisition card: for recording audio signals.
Ultra-sensitive SF using the broadband-based dual-optical comb spectrum6The invention also provides a gas decomposition component detection system
Ultra-sensitive SF based on broadband double-optical-comb spectrum6A method for detecting a gas decomposition component, the method comprising the steps of:
step 1: the output light of the two broadband optical comb lasers is spatially superposed through a beam combiner to form a double optical comb laser beam; here, the spectrum of the optical comb needs to cover a plurality of molecular absorption peaks;
step 2: laser of the double optical comb is emitted into the enhanced gas sample cell and coupled into the hollow optical fiber through the lens; the hollow optical fiber contains gas molecules to be detected; when the nth comb tooth frequency of the two optical combs is in the frequency spectrum range of the absorption peak of the gas molecule, the molecule absorbs the optical comb photons of the frequency and enters a high excitation state of a vibration energy level, the vibration frequency is equal to the frequency of the excitation light, namely (f) is respectively02+nfr2) And (f)01+nfr1) (ii) a Generating a beat signal between two vibrational states of different frequencies, i.e. fb＝|(f02+nfr2)-(f01+nfr1) L, |; under the action of photoacoustic effect, the vibration of molecule is converted into audio signal with frequency fb；
And step 3: the optical fiber is wound around the microphone, and the microphone can effectively receive the audio signal caused by molecular vibration, namely the beat signal fb；
And 4, step 4: the audio signal is amplified after passing through an amplifier and then recorded by a data acquisition card; the recorded signal is a time domain waveform; obtaining the frequency of a beat frequency signal after discrete Fourier transform is carried out on the waveform; because different absorption peaks and absorption frequencies are different, the generated beat frequency signals are also different, so that the beat frequency signals can be distinguished in a mode of measuring the beat frequency signal frequency, and the simultaneous measurement of a plurality of gas molecule absorption peaks is realized; meanwhile, because the laser and the molecules are bound in the hollow optical fiber, the interaction distance and the absorption cross section of the light and the molecules are increased, and the detection sensitivity is improved, so that the ultra-sensitive spectrum detection of the decomposition product of the multi-component sulfur hexafluoride electrical equipment is realized.
The photoacoustic spectrometry method utilizes the broadband dual-optical comb light source to measure the photoacoustic spectrum, increases the problem of simultaneous measurement of multiple absorption peaks of photoacoustic spectrometry, improves the resolution capability of fault gas detection of complex multi-component power equipment, and solves the problems of cross sensitivity and poor selectivity of the traditional technology; the spectral width and the detection sensitivity of the spectrum are increased by adopting a method of combining the hollow optical fiber with the photoacoustic spectrum and the optical comb spectrum. Compared with the traditional gas spectrum analysis method, the method has the advantages of high sensitivity, high resolution, simultaneous detection of a plurality of absorption peaks and the like, and can realize efficient and accurate analysis of the spectrum lines of the characteristic gas of the power grid fault equipment.
Drawings
FIG. 1 is a schematic structural view of the present invention;
FIG. 2 is a schematic diagram of the beat frequency of the dual optical comb of the present invention;
FIG. 3 is a diagram of the contents of an enhanced gas cell according to the present invention;
fig. 4 is a schematic structural diagram of an embodiment of the present invention.
In the figure, 1, 2-optical comb laser source, 3-polarization controller, 4-beam combiner, 5-half wave plate, 6-enhanced gas sample cell, 7-lens, 8-hollow fiber, 9-microphone, 10-filter, 11-audio amplifier, 12-data acquisition card.
Detailed Description
The invention is described in further detail below with reference to the following figures and specific examples:
ultra-sensitive SF based on broadband double-optical-comb spectrum6A gas decomposition component detection system (fig. 1), the system comprising:
1) an optical comb light source: the optical comb light sources are two, and the carrier envelope phase zero frequency and the repetition frequency of the optical comb light sources are respectively as follows: f. of01And fr1And f02And fr2(ii) a Each optical comb is composed of n frequency teeth; wherein the frequency of the nth comb is f0+nfr(FIG. 2). Frequency difference f of nth comb teeth of two optical combsb＝|(f02+nfr2)-(f01+nfr1) And then the beat frequency signals of the nth comb teeth of the two optical combs. By tuning the laser parameter, i.e. f0And frCan make the beat frequency signal fbIn the audio frequency domain (20Hz-20 kHz).
2) A beam combiner: for coupling the output light of the two optical combs into spatially coincident light beams.
3) Enhancement mode gas appearance pond: the enhanced gas sample cell (figure 3) is used for ultrasensitive gas photoacoustic spectrometry detection, and comprises a gas inlet, a gas outlet, a light-transmitting window, a section of hollow optical fiber wound on a microphone and a coupling lens for coupling laser into the optical fiber. The hollow optical fiber is an optical transmission medium in which an optical fiber is hollow to form a cylindrical space.
4) A microphone: for receiving an audio signal.
5) The audio amplifier: for amplifying weak signals.
6) A data acquisition card: for recording audio signals.
Ultra-sensitive SF based on broadband dual-optical comb spectrum of the present invention as shown in FIG. 46The gas decomposition component detection system comprises optical comb laser sources 1 and 2, a polarization controller 3, a beam combiner 4, a half-wave plate 5, an enhanced gas sample cell 6, a lens 7, a hollow optical fiber 8, a microphone 9, a filter 10, an audio amplifier 11 and a data acquisition card 12. The output light of the optical combs 1 and 2 is spatially combined by the beam combiner 4, wherein one path of the optical comb light passes through a polarization controller to adjust the polarization state, so that the polarization of the two paths of the optical combs is the same. Spatial coincidence and polarization state control are necessary conditions for realizing the optical beat frequency of the two. After the combination, the laser passes through a half-wave plate, the polarization state of the laser is optimized, and the laser can enter the hollow optical fiber 8 with the optimal coupling efficiency after passing through the lens 7. The double-optical comb light beam interacts with the gas molecules to be measured in the optical fiber, generates an acoustic wave signal through the photoacoustic effect after being absorbed, and is received by the microphone 9. The output audio signal of the microphone 9 is filtered by the filter 10 to remove background and high frequency noise, amplified by the audio amplifier 11, and finally recorded and processed by the data acquisition card 12.
In the above technical scheme, the gas to be measured is introduced into the enhanced gas sample pool 6 through the gas inlet. During measurement, the gas inlet and the gas outlet of the enhanced gas sample pool are closed, and gas in the pool enters the hollow optical fiber through a diffusion process. After the measurement is finished, the gas pool is vacuumized through the gas outlet, and the original residual sample gas is discharged.
In the above technical solution, the microphone 9 is used for measuring the acoustic wave signal generated after the molecules absorb the light of the double optical combs, and the signal frequency is equal to the beat frequency signal f between the absorbed double optical combsb. Different absorption peak yieldThe generated audio frequencies are different, and the method can be used for distinguishing absorption peaks, so that the identification of gas types is realized.
In the above technical scheme, the electrical signal is amplified by the amplifier 11, collected by the data acquisition card 12, and the photoacoustic spectrum intensity signal of the gas to be detected is obtained by using the fourier transform method, and the signal is in direct proportion to the concentration of the gas and can be used for identifying the concentration of the gas and the type of the gas.
Ultra-sensitive SF using the broadband-based double-optical comb spectrum6The gas decomposition component detection system and the detection method of the embodiment comprise the following steps:
step 1: the output light of the two broadband optical comb lasers 1 and 2 is spatially superposed through a beam combiner 4 to form a double optical comb laser beam;
step 2: laser of the double optical comb is emitted into the enhanced gas sample cell 6 and coupled into the hollow optical fiber 8 through the lens 7; the hollow optical fiber contains gas molecules to be detected, and under the action of photoacoustic effect, the vibration of the molecules is converted into audio signals with the signal frequency of fb；
And step 3: the optical fiber is wound around the microphone, and the microphone can effectively receive the audio signal caused by molecular vibration, namely the beat signal fb；
And 4, step 4: the audio signal is amplified after passing through an amplifier and then recorded by a data acquisition card; the recorded signal is a time domain waveform; obtaining the frequency of a beat frequency signal after discrete Fourier transform is carried out on the waveform; because different absorption peaks and absorption frequencies are different, the generated beat frequency signals are also different, so that the beat frequency signals can be distinguished in a mode of measuring the beat frequency signal frequency, and the simultaneous measurement of a plurality of gas molecule absorption peaks is realized; meanwhile, because the laser and the molecules are bound in the hollow optical fiber, the interaction distance and the absorption cross section of the light and the molecules are increased, and the detection sensitivity is improved, so that the ultra-sensitive spectrum detection of the decomposition product of the multi-component sulfur hexafluoride electrical equipment is realized.
In the above technical solution, as shown in fig. 2, the optical comb is a broadband coherent laser source with a spectrum range of 1-12 μm, and the spectrum of the optical comb is represented by a spectrum combThe distribution of the teeth, that is, the spectrum is composed of N frequency teeth or comb teeth which are distributed at equal intervals, N is any integer, and N is usually 103～106Wherein each frequency tooth is equivalent to a beam of single longitudinal mode laser, and the frequency of the first comb tooth of the optical comb is f0The frequency spacing of comb teeth adjacent to each other is frThen, the absolute frequency of the nth comb is expressed as: f. ofn＝f0+nfrWherein 0 is<n<N。
In the above technical solution, the dual optical comb refers to that the carrier envelope phase zero frequency (i.e. the frequency of the first comb tooth) and the repetition frequency are respectively: f. of01And fr1And f02And fr2The optical comb of (1).
In the above technical solution, when the nth comb tooth frequency of the two optical combs is within the spectrum range of the absorption peak of the gas molecule, the molecule will absorb the optical comb photons of the frequency and enter the high excited state of the vibration level, the vibration frequency is equal to the frequency of the excited light, i.e., (f) is respectively02+nfr2) And (f)01+nfr1) (ii) a Generating a beat signal between two vibrational states of different frequencies, i.e. fb＝|(f02+nfr2)-(f01+nfr1) L. The excited molecules induce a periodic variation of the refractive index of the medium with a periodic frequency fb. This change in refractive index will result in a frequency fbThe sound waves of (2) are transmitted to the microphone 9 through the gas and the hollow fiber. Because the optical comb source has broadband spectral characteristics, a plurality of molecular absorption peaks can be simultaneously excited at one time to generate acoustic wave signals with different frequencies. The sound wave frequency and the absorption peak or the absorption spectral line are in one-to-one correspondence, so that the audio signals can be detected simultaneously through the microphone 9, and the purpose of measuring a plurality of absorption peaks is achieved.
Among the above-mentioned technical scheme, hollow fiber 8's effect is in the physical space of narrow and small with light beam and molecule constraint, increases the interaction cross-section, and simultaneously, optic fibre can increase light and molecule interaction length, avoids the restriction of sample cell physical space to effective optical path, finally reaches the purpose that promotes detectivity.
In the above technical scheme, the sulfur hexafluorideThe decomposition product of electrical equipment refers to fault-characteristic gas of electrical equipment with infrared absorption characteristic, such as H2S、HF、SO2、CO、CO2。
Example 1:
the measurement was performed for an absorption peak group of Hydrogen Fluoride (HF) gas molecules in the vicinity of 1.28 μm as an example.
As shown in FIG. 4, two optical comb light sources with center wavelengths around 1.28 μm were used. One of which passes through a polarization controller to adjust the polarization state. The two optical combs are spatially overlapped after passing through a beam combiner 4 with the ratio of 50: 50. Repetition frequency (i.e. comb tooth spacing) f of two optical combsr1＝10MHz，fr210MHz +1Hz, carrier envelope phase zero frequency f0And are all set to 0 (typically implemented by adjusting the optical comb pump optical power).
The double-light comb light beam enters an enhanced gas sample pool 6 filled with HF gas after passing through a half-wave plate 5. The light beam enters a lens with numerical aperture NA 0.5 and is coupled into the hollow optical fiber. The hollow optical fiber has an aperture of 10 μm and a length of 10 m. The optical fiber is wound around the microphone 9. The photoacoustic signal caused by the optical comb is captured by a microphone 9 attached to the cell wall and converted into an electric signal, and the electric signal is subjected to noise suppression and amplification and then sent to a data acquisition card for acquisition and processing. The collected signals are time domain signals, the frequency characteristics of the sound waves are obtained through Fourier time-frequency transformation, and then the spectral information corresponding to the HF is obtained. For example, if the nth teeth of the two optical combs are absorbed by HF molecules, a frequency f is generatedbOf the signal of (1). Beat signal f between nth comb teethb＝n·|fr2-fr1|。fr2-fr11Hz is a known quantity, fbIs the measurement of the microphone 9. From this, the value of n can be calculated. Thus, the absorption line corresponds to a frequency nfr2And nfr1The intensity is proportional to the amplitude of the sound wave audio signal.
In summary, the invention provides an ultrasensitive SF based on broadband dual-optical comb spectrum6Gas decomposition component detection system and method that can achieve simultaneous measurement of multiple molecular absorption peaks and with sensitivity and selectivityThe method has advantages in sex, can obtain the absorption spectrum information of molecules which are difficult to distinguish when a single or a plurality of molecules are close to each other, and simultaneously solves the problem of cross sensitivity among gas absorption peaks. The system can realize high-sensitivity quick-response characteristic gas (such as SF) in the aspect of power grid safety maintenance6Gas and its decomposition products) spectral line parameters. The method can be used for measuring important information such as concentration, content, type and the like of the gas in a sensitive and accurate mode, and provides a way for the operation safety of a power grid and the detection of fault characteristic gas.
Details not described in this specification are within the skill of the art that are well known to those skilled in the art.
Claims (5)
1. Ultra-sensitive SF based on broadband double-optical-comb spectrum6Gas decomposition component detecting system, its characterized in that: the system comprises:
an optical comb light source: for generating a light source;
a beam combiner: for coupling the output light of the optical comb into spatially coincident light beams;
enhancement mode gas appearance pond: the method is used for ultra-sensitive gas photoacoustic spectrum detection;
a microphone: for receiving an audio signal;
the audio amplifier: for amplifying weak signals;
a data acquisition card: for recording audio signals.
2. Ultra-sensitive SF according to claim 1 based on broadband dual optical comb spectrum6Gas decomposition component detecting system, its characterized in that:
the optical comb light sources are two, and the carrier envelope phase zero frequency and the repetition frequency of the optical comb light sources are respectively as follows: f. of01And fr1And f02And fr2(ii) a Each optical comb is composed of n frequency teeth; wherein the frequency of the nth comb is f0+nfr. Frequency difference f of nth comb teeth of two optical combsb＝|(f02+nfr2)-(f01+nfr1) I, then the two optical combsBeat frequency signal of n comb teeth by tuning laser parameter f0And frCan make the beat frequency signal fbIn the audio frequency domain (20Hz-20 kHz).
3. Ultra-sensitive SF according to claim 1 based on broadband dual optical comb spectrum6Gas decomposition component detecting system, its characterized in that:
the enhanced gas sample cell comprises a gas inlet, a gas outlet, a light-transmitting window, a section of hollow optical fiber wound on the microphone and a coupling lens for coupling laser into the optical fiber. The hollow optical fiber is an optical transmission medium in which an optical fiber is hollow to form a cylindrical space.
4. Ultra-sensitive SF according to claim 3 based on broadband dual optical comb spectrum6Gas decomposition component detecting system, its characterized in that: the hollow optical fiber is used for binding light beams and molecules in a narrow physical space, so that an interaction section is increased, meanwhile, the interaction length of the light and the molecules can be increased, the limitation of the physical space of the sample pool on an effective optical path is avoided, and the purpose of improving the detection sensitivity is finally achieved.
5. Ultra-sensitive SF using broadband dual optical comb spectra based as claimed in claims 1-46A gas decomposition component detection system, the detection method of said system comprising the steps of:
step 1: the output light of the two broadband optical comb lasers is spatially superposed through a beam combiner to form a double optical comb laser beam; here, the spectrum of the optical comb needs to cover a plurality of molecular absorption peaks;
step 2: laser of the double optical comb is emitted into the enhanced gas sample cell and coupled into the hollow optical fiber through the lens; the hollow optical fiber contains gas molecules to be detected; when the nth comb tooth frequency of the two optical combs is in the frequency spectrum range of the absorption peak of the gas molecule, the molecule absorbs the optical comb photons of the frequency and enters a high excitation state of a vibration energy level, the vibration frequency is equal to the frequency of the excitation light, namely (f) is respectively02+nfr2) And (f)01+nfr1) (ii) a Generating a beat signal between two vibrational states of different frequencies, i.e. fb＝|(f02+nfr2)-(f01+nfr1) L, |; under the action of photoacoustic effect, the vibration of molecule is converted into audio signal with frequency fb；
And step 3: the optical fiber is wound around the microphone, and the microphone can effectively receive the audio signal caused by molecular vibration, namely the beat signal fb；
And 4, step 4: the audio signal is amplified after passing through an amplifier and then recorded by a data acquisition card; the recorded signal is a time domain waveform; obtaining the frequency of a beat frequency signal after discrete Fourier transform is carried out on the waveform; because different absorption peaks and absorption frequencies are different, the generated beat frequency signals are also different, so that the beat frequency signals can be distinguished in a mode of measuring the beat frequency signal frequency, and the simultaneous measurement of a plurality of gas molecule absorption peaks is realized; meanwhile, because the laser and the molecules are bound in the hollow optical fiber, the interaction distance and the absorption cross section of the light and the molecules are increased, and the detection sensitivity is improved, so that the ultra-sensitive spectrum detection of the decomposition product of the multi-component sulfur hexafluoride electrical equipment is realized.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114018829A (en) * | 2021-10-27 | 2022-02-08 | 国网四川省电力公司电力科学研究院 | Tuning fork resonance enhanced double-optical comb multi-component gas detection system |
| CN114878496A (en) * | 2022-04-16 | 2022-08-09 | 国网江苏省电力有限公司超高压分公司 | Annular optical fiber SF based on ultraviolet absorption spectrum 6 Decomposition product detection device and method |
| CN114018829B (en) * | 2021-10-27 | 2024-05-10 | 国网四川省电力公司电力科学研究院 | Double-optical comb multicomponent gas detection system with tuning fork resonance enhancement |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN203658243U (en) * | 2013-11-27 | 2014-06-18 | 武汉豪迈光电科技有限公司 | C2H2 and CH4 detection device based on photoacoustic spectrometry |
| CN104849214A (en) * | 2015-04-20 | 2015-08-19 | 北京航天控制仪器研究所 | Enhanced multi-group photoacoustic spectrum gas sensing device based on quartz tuning fork |
| CN110044824A (en) * | 2019-05-06 | 2019-07-23 | 安徽大学 | A kind of double spectroscopic gas detection devices and method based on quartz tuning-fork |
| CN209495963U (en) * | 2018-11-27 | 2019-10-15 | 国网重庆市电力公司电力科学研究院 | A kind of infrared photoacoustic spectra detection system |
| CN111751323A (en) * | 2020-07-22 | 2020-10-09 | 云南电网有限责任公司电力科学研究院 | A dispersion spectrum device for gaseous detection of SF6 |
-
2020
- 2020-12-15 CN CN202011480526.6A patent/CN112710628B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN203658243U (en) * | 2013-11-27 | 2014-06-18 | 武汉豪迈光电科技有限公司 | C2H2 and CH4 detection device based on photoacoustic spectrometry |
| CN104849214A (en) * | 2015-04-20 | 2015-08-19 | 北京航天控制仪器研究所 | Enhanced multi-group photoacoustic spectrum gas sensing device based on quartz tuning fork |
| CN209495963U (en) * | 2018-11-27 | 2019-10-15 | 国网重庆市电力公司电力科学研究院 | A kind of infrared photoacoustic spectra detection system |
| CN110044824A (en) * | 2019-05-06 | 2019-07-23 | 安徽大学 | A kind of double spectroscopic gas detection devices and method based on quartz tuning-fork |
| CN111751323A (en) * | 2020-07-22 | 2020-10-09 | 云南电网有限责任公司电力科学研究院 | A dispersion spectrum device for gaseous detection of SF6 |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114018829A (en) * | 2021-10-27 | 2022-02-08 | 国网四川省电力公司电力科学研究院 | Tuning fork resonance enhanced double-optical comb multi-component gas detection system |
| CN114018829B (en) * | 2021-10-27 | 2024-05-10 | 国网四川省电力公司电力科学研究院 | Double-optical comb multicomponent gas detection system with tuning fork resonance enhancement |
| CN114878496A (en) * | 2022-04-16 | 2022-08-09 | 国网江苏省电力有限公司超高压分公司 | Annular optical fiber SF based on ultraviolet absorption spectrum 6 Decomposition product detection device and method |
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