CN102288577B - System and method for measuring gas parameters by utilizing laser spectrum - Google Patents

Abstract

The invention discloses a system and method for measuring gas parameters by utilizing a laser spectrum. In the system for measuring the gas parameters by utilizing the laser spectrum, a locking device locks wavelength of a laser signal emitted by a laser output head of a first laser generator to be at a center position of an absorption line of a target molecule in a target molecule sample cell in which a first locking channel is located, a control device acquires the laser signal which is emitted by the laser output head of the first laser generator, is detected by a detector and enters into a receiving light path device and a sample measuring channel as well as a laser signal which is emitted by the laser output head of a second laser generator and enters into the sample measuring channel, analog-digital conversion is carried out on the acquired laser signals, and concentration of the measured target gas is measured according to analog-digital conversion result. The measuring speed of the system is restricted by the time for the control device to acquire data while minimum of the current time for acquiring data is in microsecond, and response time of a laser demodulation frequency is greatly improved compared with the prior art, thus the measuring speed is improved and time consumption is reduced.

Description

A kind of system and method that utilizes laser spectrum measurement gas parameter

Technical field

The application relates to the laser measuring technique field, particularly relates to a kind of system and method that utilizes laser spectrum measurement gas parameter.

Background technology

The laser absorption spectrum technology is a kind of technology of measuring measured target gas temperature and concentration, be specially: many Absorption Lines to a certain component in gas are measured, obtain the absorptivity of this component, further according to the corresponding relation of absorptivity and measured target gas temperature, and the corresponding relation of the concentration of absorptivity and measured target gas, the concentration of acquisition measured target gas temperature and measured target gas.

Laser absorption spectrum technology commonly used comprises direct absorption spectroscopy and Wavelength modulation spectroscopy method at present, these two kinds of methods are referred to as the scanning wavelength method, the spectrum of the laser by recording certain wavelength band, carry out integration to spectral line, thereby obtain the integration absorptance R of two absorption lines:

$R=\frac{\underset{v_1}{\overset{v_1^{\&prime;}}{\&Integral;}}{S}_1\left(T\right){\mathrm{\&phi;}}_1(v-v_{01})\mathrm{dv}}{\underset{v_2}{\overset{v_2^{\text{\&prime;}}}{\&Integral;}}{S}_2\left(T\right){\mathrm{\&phi;}}_2(v-v_{02})\mathrm{dv}}=\frac{S_1\left(T_0\right)}{S_2\left(T_0\right)}\exp (-\frac{\mathrm{hc}}{k_B}(E_1^{\&prime;\&prime;}-{\mathrm{<figure-callout\; id="2"\; label="E"\; filenames="HDA00002329673700032.png"\; state="\{\{state\}\}">E</figure-callout>}}_2^{\&prime;\&prime;})(\frac{1}{T}-\frac{1}{T_0}))$

Wherein: v ₀₁And v ₀₂Be respectively the center of two Absorption Lines, h is the Planck constant, and c is the light velocity, k _BFor Boltzmann constant, T ₀Standard temperature 296K for the database use, S (T) is absorption line strengths, φ (v) is linear function, widen linear and pressure Lorentz lorentz's type is widened linear convolution and obtained by the Doppler of Gaussian, it " being state energy levels under transition, and linear function meets ∫ φ (v) dv=1, E.Database HITRAN2008 discloses the Absorption Line center v of 29 kinds of main atmospheric molecules ₀, S (T) and E ".Search and v in database HITRAN2008 ₀₁And v ₀₂Corresponding S (T ₀) and E ", further combined with the R that records, calculate gas temperature value T.

Simultaneously, measured target gas absorptivity meet Beer-Lambert relational expression, T _v=I _v/ I ₀=exp (k _vL).

Wherein: T _vLaser transmissivity through the L light path in medium, k _vFor absorptivity.

Absorptivity k _vUnder pressure P, the concentration X of certain measured target gas _gas, the function of absorption line strengths S (T) and linear function φ (v), and linear function meets ∫ φ (v) dv=1.Absorptivity k _vCan be expressed as: k _v=S (T) X _gasP φ (v).Above-mentioned two kinds of methods can be measured laser transmissivity through the L light path in medium, and then extrapolate absorptivity k _v, further according to absorptivity k _vComputing formula obtain the concentration of measured target gas.

Yet, above-mentioned two kinds of methods are when the concentration of the temperature of measuring measured target gas and measured target gas, need to scan the optical maser wavelength in certain wavelength band and recording laser spectrum, therefore measuring speed is subject to the laser modulation frequency limitation, and the response time of laser modulation frequency is 0.1ms the soonest, thereby reduced measuring speed, increased time loss.

Summary of the invention

In view of this, the embodiment of the present application discloses a kind of system and method that utilizes laser spectrum measurement gas parameter,, to improve measuring speed, reduces time loss.Technical scheme is as follows:

The embodiment of the present application discloses a kind of system of utilizing laser spectrum measurement gas parameter, comprise: the first locking channel, two sample measurement channel, the first laser generator, the second laser generator, signal generator, detector, receiving light path device, locking device and control device, wherein:

Described the first laser generator and described the second laser generator comprise laser power controller and Laser output head, described laser power controller is used for receiving the signal that described signal generator produces, laser signal to the first-born one-tenth of described Laser output is modulated, and the laser signal after modulation is gone out by described Laser output hair;

Described locking device, be used for receiving the laser signal that described detector detects, the laser signal that detects is carried out demodulation according to the signal that described signal generator produces, generate feedback control signal, control the laser power controller of the first laser generator, the Absorption Line center v of wavelength signals target molecule in described the first locking channel target molecule sample cell of living in of the laser after the modulation that goes out with the Laser output hair that locks the first laser generator ₀₁Place, wherein the laser signal that detects of detector is to enter the laser signal that the Laser output hair in the first laser generator of described receiving light path device and the first locking channel goes out;

Described control device, be used for gathering the laser signal that described detector detects, the laser signal that collects is carried out analog to digital conversion, concentration according to analog to digital conversion outcome measurement measured target gas, the laser signal that detector detects is to enter the laser signal that the Laser output hair in the first laser generator of described receiving light path device and described sample measurement channel goes out, and enters the laser signal that the Laser output hair in the second laser generator of described sample measurement channel goes out.

Preferably, described receiving light path device comprises: the first beam splitter and the first catoptron; Laser signal after the modulation that described the first beam splitter goes out the Laser output hair in described the first laser generator is divided into reflected light signal and optical signal transmissive, wherein reflected light signal enters described sample measurement channel through described the first mirror reflects, and optical signal transmissive enters described the first locking channel.

Preferably, also comprise: the second locking channel;

Described receiving light path device also comprises: the second beam splitter and the second catoptron; Laser signal after the modulation that described the second beam splitter goes out the Laser output hair in described the second laser generator is divided into reflected light signal and optical signal transmissive, wherein reflected light signal enters described the second locking channel through described the second mirror reflects, and optical signal transmissive enters described sample measurement channel.

Preferably, also comprise: the detector and the locking device that are connected with described the second locking channel;

This locking device, be used for receiving the laser signal that described detector detects, the laser signal that detects is carried out demodulation according to the signal that described signal generator produces, generate feedback control signal, control the laser power controller of the second laser generator, the Absorption Line center v of wavelength target molecule in described the second locking channel target molecule sample cell of living in of the laser signal after the modulation that goes out with the Laser output hair that locks the second laser generator ₀₂Place, wherein the laser signal that detects of detector is to enter the laser signal that the Laser output hair in the second laser generator of described receiving light path device and the second locking channel goes out;

Described control device, also be used for gathering the laser signal that described detector detects, the laser signal that collects is carried out analog to digital conversion, according to the temperature of analog to digital conversion outcome measurement measured target gas, the laser signal that detector detects is the laser signal that enters after the modulation of described receiving light path device and described sample measurement channel.

Preferably, also comprise: two reference channels;

Described receiving light path device also comprises: the 3rd beam splitter and the 4th beam splitter;

The reflected light signal of described the first beam splitter is reflected light signal and optical signal transmissive through described the 3rd beam splitter beam splitting, and the reflected light signal of the 3rd beam splitter enters a reference channel, and the optical signal transmissive of the 3rd beam splitter is received by described the first catoptron;

The reflected light signal of described the second beam splitter is reflected light signal and optical signal transmissive through described the 4th beam splitter beam splitting, and the reflected light signal of the 4th beam splitter enters another reference channel, and the optical signal transmissive of the 4th beam splitter is received by described the second catoptron.

Preferably, also comprise: the detector that is connected with described reference channel respectively;

Described control device, also be used for gathering the laser signal that described detector detects, the laser signal that collects is carried out analog to digital conversion, according to the temperature of analog to digital conversion outcome measurement measured target gas and the concentration of measured target gas, wherein the laser signal that detects of detector is the laser signal that enters described receiving light path device and described reference channel, and the laser signal that enters described receiving light path device and described sample measurement channel.

Preferably, described locking device comprises: lock-in amplifier and proportion integration differentiation PID amplifier;

Described lock-in amplifier, be used for receiving the laser signal that described detector detects, and the laser signal that detects is carried out demodulation according to the signal that described signal generator produces, and the signal after demodulation is sent;

Described PID amplifier, for the signal after the demodulation that receives described lock-in amplifier transmission, signal after described demodulation is carried out proportional integral to be amplified, generate feedback control signal, control described laser power controller, with the Absorption Line center of wavelength target molecule in described locking channel target molecule sample cell of living in of locking the laser signal after the modulation that described Laser output hair goes out.

The embodiment of the present application also discloses a kind of method of utilizing laser spectrum measurement gas parameter, comprising:

Laser power controller receives the signal that signal generator produces, and the laser signal of the first-born one-tenth of Laser output is modulated, and the laser signal after modulation is gone out by the Laser output hair;

The laser signal that the locking device pick-up probe detects, the signal that the laser signal basis signal generator that detects is produced carries out demodulation, generate feedback control signal, control the laser power controller of the first laser generator, the Absorption Line center v of wavelength target molecule in the first locking channel target molecule sample cell of living in of the laser signal that goes out with the Laser output hair that locks the first laser generator ₀₁Place, wherein the laser signal that detects of detector is to enter the laser signal that the Laser output hair in the first laser generator of receiving light path device and the first locking channel goes out;

Control device gathers the laser signal that detector detects, the laser signal that collects is carried out analog to digital conversion, concentration according to analog to digital conversion outcome measurement measured target gas, the laser signal that detector detects is to enter the laser signal that the Laser output hair in the first laser generator of receiving light path device and sample measurement channel goes out, and enters the laser signal that the Laser output hair in the second laser generator of sample measurement channel goes out.

Preferably, also comprise:

The laser signal that the locking device pick-up probe detects, the signal that the laser signal basis signal generator that detects is produced carries out demodulation, generate feedback control signal, control the laser power controller of the second laser generator, the Absorption Line center v of wavelength target molecule in the second locking channel target molecule sample cell of living in of the laser signal that goes out with the Laser output hair that locks the second laser generator ₀₂Place, wherein the laser signal that detects of detector is to enter the laser signal that the Laser output hair in the second laser generator of receiving light path device and the second locking channel goes out;

Control device gathers the laser signal that detector detects, the laser signal that collects is carried out analog to digital conversion, according to the temperature of analog to digital conversion outcome measurement measured target gas, the laser signal that detector detects is the laser signal that enters described receiving light path device and described sample measurement channel.

Preferably, described concentration according to analog to digital conversion outcome measurement measured target gas is specially:

Obtain laser signal that the Laser output hair of the first laser generator the goes out absorption peak H in the Absorption Line center according to the analog to digital conversion result;

In conjunction with formula

Draw the concentration of measured target gas, wherein: H is absorption peak, P is the general pressure of all gas in the sample pond, L is the length of the light path of laser signal in the sample pond, φ (v) is linear function, and linear function meets ∫ φ (v) dv=1, and S (T) is absorption line strengths;

Temperature according to analog to digital conversion outcome measurement measured target gas is specially: according to the analog to digital conversion result, obtain laser signal that in the first laser generator and the second laser generator, the Laser output hair goes out respectively at target molecule Absorption Line center v ₀₁And v ₀₂The absorption peak at place compares R;

In conjunction with formula $R=k_{v,1}/k_{v,2}=\frac{S_1\left(T_0\right){\mathrm{\&phi;}}_1\left(v\right)}{S_2\left(T_0\right){\mathrm{\&phi;}}_2\left(v\right)}\exp (-\frac{\mathrm{hc}}{k_B}(E_1^{\&prime;\&prime;}-{\mathrm{<figure-callout\; id="2"\; label="E"\; filenames="HDA00002329673700032.png"\; state="\{\{state\}\}">E</figure-callout>}}_2^{\&prime;\&prime;})(\frac{1}{T}-\frac{1}{T_0}))$ Draw the temperature of measured target gas, wherein: h is the Planck constant, and c is the light velocity, k _BFor Boltzmann constant, T ₀" be state energy levels under transition, S (T for the standard temperature 296K that database uses, E ₀) be absorption line strengths, φ (v) is linear function, and linear function meets ∫ φ (v) dv=1.

The application technique scheme, the Absorption Line center v of wavelength locking target molecule in the first locking channel target molecule sample cell of living in of the laser signal after the modulation that locking device goes out the Laser output hair of the first laser generator ₀₁Place, the laser signal that the Laser output hair of the first laser generator that enters receiving light path device and sample measurement channel that the control device collection is detected by detector goes out, and the laser signal that goes out of the Laser output hair that enters the second laser generator of sample measurement channel, the laser signal that collects is carried out analog to digital conversion, according to the concentration of analog to digital conversion outcome measurement measured target gas.The embodiment of the present application is disclosed utilizes the measuring speed of the system of laser spectrum measurement gas parameter to be subject to the data acquisition time of control device, be microsecond and data acquisition time is minimum at present, response time with respect to laser modulation frequency in prior art improves greatly, thereby improved measuring speed, reduced time loss.

Description of drawings

In order to be illustrated more clearly in the embodiment of the present application or technical scheme of the prior art, below will the accompanying drawing of required use in embodiment or description of the Prior Art be briefly described, apparently, the accompanying drawing that the following describes is only some embodiment that put down in writing in the application, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain according to these accompanying drawings other accompanying drawing.

Fig. 1 is the disclosed a kind of structural representation that utilizes the system of laser spectrum measurement gas parameter of the embodiment of the present application;

Fig. 2 is the disclosed another kind of structural representation that utilizes the system of laser spectrum measurement gas parameter of the embodiment of the present application;

Fig. 3 is disclosed another structural representation that utilizes the system of laser spectrum measurement gas parameter of the embodiment of the present application;

Fig. 4 is the measured target gas temperature curve map that the embodiment of the present application is measured;

Fig. 5 is the measured target gas temperature curve map that the scanning wavelength method is measured;

Fig. 6 is the structural representation of locking device in the disclosed system of utilizing laser spectrum measurement gas parameter of the embodiment of the present application;

Fig. 7 is the disclosed a kind of process flow diagram that utilizes the method for laser spectrum measurement gas parameter of the embodiment of the present application;

Fig. 8 is the disclosed another kind of process flow diagram that utilizes the method for laser spectrum measurement gas parameter of the embodiment of the present application.

Embodiment

, for above-mentioned purpose, the feature and advantage that make the application can become apparent more, below in conjunction with the drawings and specific embodiments, the application is described in further detail.

An embodiment

See also Fig. 1, Fig. 1 is the disclosed system of utilizing laser spectrum measurement gas parameter of the embodiment of the present application, comprising: the first locking channel 101, two sample measurement channel 102 and the 103, first laser generator 104, the second laser generator 105, signal generator 106, detector 107, detector 108, detector 109, receiving light path device 110, locking device 111 and control device 112.Wherein:

The first locking channel 101 is arranged in target molecule sample cell 122, and as the water sample pond, the Absorption Line center of the first locking channel 101 is an Absorption Line center v of target molecule in the target molecule sample cell ₀₁ Sample measurement channel 102 and 103 is arranged in same sample pond 123.

The first laser generator 104 and the second laser generator 105 comprise respectively laser power controller and Laser output head, laser power controller is used for receiving the signal that signal generator 106 produces, laser signal to the first-born one-tenth of Laser output is modulated, and the laser signal after modulation is gone out by the Laser output hair.

Laser signal after the modulation that the Laser output hair of the first laser generator 104 goes out is divided into the two-way laser signal through receiving light path device 110, and a road laser signal enters the first locking channel 101.The laser signal that detector 107 is surveyed in the first locking channel 101, send to locking device 111 with this laser signal.

Locking device 111 receives the signal that signal generator 106 produces simultaneously, and the signal that basis signal generator 106 produces carries out demodulation to the laser signal that receives, and generates feedback control signal, controls the laser power controller of the first laser generator 104.The laser power controller of the first laser generator 104 is further according to this feedback control signal modulated laser delivery, the Absorption Line center v of wavelength target molecule in the first locking channel 101 target molecule sample cell of living in of the laser signal that goes out with the Laser output hair that locks the first laser generator 104 ₀₁Place.

It is 50mV that above-mentioned signal generator 106 can produce an amplitude, modulating frequency is the sinusoidal signal of 13kHz, this sinusoidal signal is applied to respectively the laser power controller of the first laser generator 104 and the second laser generator 105, by laser power controller, the laser signal of the first-born one-tenth of Laser output is carried out Sine Modulated.Signal generator 106 can also produce cosine signal, by laser power controller, the laser signal of the first-born one-tenth of Laser output is carried out cosine modulation.The amplitude of signal generator 106 generation signals and modulating frequency be difference according to the different application scene, Absorption Line center as the first locking channel in the different application scene is different, the Absorption Line center of the first locking channel that signal generator 106 is corresponding different, produce the signal with different amplitudes and modulating frequency.

Another road laser signal that the first received light path device 110 of laser generator 104 is divided into enters sample measurement channel 102, surveyed by detector 108, and the laser signal that detector 108 will detect sends to control device 112.The laser signal that the Laser output hair of the second laser generator 105 goes out directly enters sample measurement channel 103, surveyed by detector 109, and the laser signal that detector 109 will detect sends to control device 112.

Receiving light path device 110 comprises: the first beam splitter 1101 and the first catoptron 1102.Laser signal after the modulation that the first beam splitter 1101 goes out the Laser output hair of described the first laser generator 104 is divided into reflected light signal and optical signal transmissive, wherein reflected light signal enters sample measurement channel 102 through the first catoptron 1102 reflections, and optical signal transmissive enters the first locking channel 101.

Control device 112, gather respectively the laser signal that detector 108 and 109 detects, and the laser signal that collects is carried out analog to digital conversion, according to the concentration of analog to digital conversion outcome measurement measured target gas.Be specially:

The analog to digital conversion result of supposing 112 pairs of detectors that collect 108 of control device and 109 laser signals that detect is respectively I ₁And I ₂, the Absorption Line center v of wavelength locking target molecule in the first locking channel 101 target molecule sample cell of living in of the laser signal after the modulation that goes out due to the Laser output hair of the first laser generator 104 ₀₁Place, and the laser signal wavelength that the Laser output hair of the second laser generator 105 goes out is placed in outside Absorption Line, so the laser signal wavelength place that the Laser output hair that the ratio of two transformation results is the first laser generator 104 goes out (is the Absorption Line center v of target molecule ₀₁Place) absorption peak H, i.e. the Absorption Line center v of target molecule ₀₁The absorption peak H at place is H=I ₁/ I ₂

After obtaining absorption peak H, in conjunction with formula

Draw the concentration of measured target gas, wherein: H is absorption peak, L is the length of the light path of laser signal in sample pond 123, can directly measure, φ (v) is linear function, by the Doppler of Gaussian, widens linear and pressure Lorentz lorentz's type is widened linear convolution and obtained, and linear function meets ∫ φ (v) dv=1, S (T) is absorption line strengths, and P is the general pressure of all gas in sample pond 123, can measure by pressure transducer.Database HITRAN2008 discloses the center v of the absorption line of 29 kinds of main atmospheric molecules ₀, S (T ₀) and E ", wherein: T ₀Standard temperature 296K for database uses, can search S (T), and then know the concentration of measured target gas in this database.

The application technique scheme, the Absorption Line center v of wavelength locking target molecule in the first locking channel 101 target molecule sample cell of living in of the laser signal after the modulation that locking device 111 goes out the Laser output hair of the first laser generator 104 ₀₁Place, laser signal after the modulation that the Laser output hair that control device 112 gathers the first laser generator 104 that enters receiving light path device 110 and sample measurement channel 102 that is detected by detector goes out, and the laser signal after the modulation that goes out of the Laser output hair that enters the second laser generator 105 of sample measurement channel 103, the laser signal that collects is carried out analog to digital conversion, according to the concentration of analog to digital conversion outcome measurement measured target gas.

The inventor sums up the disclosed measuring speed that utilizes the system of laser spectrum measurement gas parameter of the embodiment of the present application through many experiments and only is subject to the data acquisition time of control device 112, be microsecond and data acquisition time is minimum at present, response time with respect to laser modulation frequency in prior art improves greatly, thereby improved measuring speed, reduced time loss.

Another embodiment

Said system embodiment can measure the concentration at measured target gas, and the temperature of measured target gas is as the important parameter of measured target gas, its measurement is conducive to the researchist natural environment and climate is analyzed.The embodiment of the present application also discloses the another kind of system of utilizing laser spectrum measurement gas parameter, and this system can be measured the temperature of measured target gas, further measures the concentration of measured target gas under different temperatures.

See also Fig. 2, Fig. 2 is the disclosed another kind of structural representation that utilizes the system of laser spectrum measurement gas parameter of the embodiment of the present application, take Fig. 1 as basis, the detector 114 and the locking device 115 that increased by the second locking channel 113, with the second locking channel 113, are connected.Wherein:

The second locking channel 113 and the first locking channel 101 are arranged in same target molecule sample cell 122, and the Absorption Line center of the second locking channel 113 is another Absorption Line center v of target molecule in target molecule sample cell 122 ₀₂

Locking device 115, be used for the laser signal that pick-up probe 114 detects, and the signal that the laser signal basis signal generator 106 that detects is produced carries out demodulation, generates feedback control signal, controls the laser power controller of the second laser generator 105.The laser power controller of the second laser generator 105 is further according to this feedback control signal modulated laser delivery, the Absorption Line center v of wavelength target molecule in the second locking channel 113 target molecule sample cell of living in of the laser signal after the modulation that goes out with locking Laser output hair ₀₂Place, wherein the laser signal that detects of detector 114 is the laser signal that enters after the modulation that the Laser output hair of the second laser generator 105 of receiving light path device 110 and the second locking channel 113 goes out.

Further, control device 112, gather respectively the laser signal that detector 108 and 109 detects, and the laser signal that collects is carried out analog to digital conversion, according to the temperature of analog to digital conversion outcome measurement measured target gas.Wherein: the laser signal that detector 108 detects, for the Laser output hair by the first laser generator 104 goes out, enters the laser signal of receiving light path device 110 and sample measurement channel 102.The laser signal that detector 109 detects is that the Laser output hair of the second laser generator 105 goes out, and enters the laser signal of receiving light path device 110 and sample measurement channel 103.

Control device 112 is specially according to the temperature of analog to digital conversion outcome measurement measured target gas:

The analog to digital conversion result of supposing 112 pairs of detectors that collect 108 of control device and 109 laser signals that detect is respectively I ₃And I ₄, the wavelength of the laser signal after the modulation that goes out due to the Laser output hair of the first laser generator 104 and the second laser generator 105 is locked in respectively the Absorption Line center v of target molecule in the first locking channel 101 and the second locking channel 113 target molecule sample cell of living in ₀₁And v ₀₂Place, so the ratio of two transformation results is target molecule at Absorption Line center v ₀₁And v ₀₂The absorption peak at place is than R, and namely absorption peak is R=I than R ₃/ I ₄

After the acquisition absorption peak is than R, in conjunction with formula $R=k_{v,1}/k_{v,2}=\frac{S_1\left(T_0\right){\mathrm{\&phi;}}_1\left(v\right)}{S_2\left(T_0\right){\mathrm{\&phi;}}_2\left(v\right)}\exp (-\frac{\mathrm{hc}}{k_B}(E_1^{\&prime;\&prime;}-{\mathrm{<figure-callout\; id="2"\; label="E"\; filenames="HDA00002329673700032.png"\; state="\{\{state\}\}">E</figure-callout>}}_2^{\&prime;\&prime;})(\frac{1}{T}-\frac{1}{T_0}))$ Draw the temperature of measured target gas, wherein: h is the Planck constant, and c is the light velocity, k _BFor Boltzmann constant, T ₀" be state energy levels under transition, S (T for the standard temperature 296K that database uses, E ₀) be absorption line strengths, φ (v) is linear function, widen linear and pressure Lorentz lorentz's type is widened linear convolution and obtained by the Doppler of Gaussian, and linear function meets ∫ φ (v) dv=1.

Control device 112 records the temperature of measured target gas as current gas temperature.After recording current gas temperature, operating personnel can operate two locking devices, control the laser power controller of any one laser generator, make laser signal after the modulation that the Laser output hair goes out be locked in the Absorption Line center v of its locking channel that enters ₀₁Place, the laser signal that the Laser output hair of another laser generator goes out is placed in outside the target molecule Absorption Line.112 concentration that can further measure the measured target gas under current gas temperature of control device, detailed process sees also an embodiment.

Above-mentioned receiving light path device 110 also comprises on Fig. 1 basis: the second beam splitter 1103 and the second catoptron 1104.Laser signal after the modulation that the second beam splitter 1103 goes out the Laser output hair of the second laser generator 105 is divided into reflected light signal and optical signal transmissive, wherein reflected light signal enters the second locking channel 113 through the second catoptron 1104 reflections, and optical signal transmissive enters sample measurement channel 103.Can find out from the system of utilizing laser spectrum measurement gas parameter shown in Figure 2: the laser signal after the modulation that the Laser output hair of above-mentioned the first laser generator 104 and the second laser generator 105 goes out all is received light path device 110 and is divided into two-way, enters respectively different passages and is surveyed by different detectors.

The application technique scheme, can realize the measurement to the concentration of measured target gas at the temperature of measured target gas and this temperature.Simultaneously, the inventor finds through many experiments, the disclosed measuring speed of the system of laser spectrum measurement gas parameter that utilizes of the embodiment of the present application still only is subject to the data acquisition time of control device 112, be microsecond and data acquisition time is minimum at present, response time with respect to laser modulation frequency in prior art improves greatly, thereby improved measuring speed, reduced time loss.

Another embodiment

Above-mentioned two system embodiments when the temperature of the concentration of measuring measured target gas and measured target gas, are not considered the impact of the laser signal after modulation that Atmospheric Absorption in the sample pond goes out the Laser output hair, reduce measuring accuracy.For fear of above-mentioned impact, the embodiment of the present application also discloses the another kind of system of utilizing laser spectrum measurement gas parameter, and structural representation sees also Fig. 3.

Fig. 3 is disclosed another structural representation that utilizes the system of laser spectrum measurement gas parameter of the embodiment of the present application,, take Fig. 2 as basis, increases by two reference channels 116 and 117, detector 118 and 119.Wherein:

Receiving light path device 110 also comprises: the 3rd beam splitter 1105 and the 4th beam splitter 1106.The reflected light signal of the first beam splitter 1101 is reflected light signal and optical signal transmissive through the 3rd beam splitter 1105 beam splitting, the optical signal transmissive that the reflected light signal of the 3rd beam splitter 1105 enters reference channel 116, the three beam splitters 1105 is received by the first catoptron 1102.

The reflected light signal of the second beam splitter 1103 is reflected light signal and optical signal transmissive through the 4th beam splitter 1106 beam splitting, the optical signal transmissive that the reflected light signal of the 4th beam splitter 1106 enters reference channel 117, the four beam splitters 1106 is received by the second catoptron 1104.

Above-mentioned reference channel 116 and 117 is arranged in atmosphere, and the signal that enters reference channel 116 and 117 is detected respectively device 118 and 119 and surveys.further, control device 112, gather detector 108, 109, 118 and 119 laser signals that detect, the laser signal that collects is carried out analog to digital conversion, according to the temperature of analog to digital conversion outcome measurement measured target gas and the concentration of measured target gas, wherein the laser signal that detects of detector 118 is the laser signal that enters receiving light path device 110 and reference channel 116, the laser signal that detector 119 detects is the laser signal that enters receiving light path device 110 and reference channel 117, the laser signal that detector 108 detects is the laser signal that enters receiving light path device 110 and sample measurement channel 102, the laser signal that detector 109 detects is the laser signal that enters receiving light path device 110 and sample measurement channel 103.

When measuring the measured target gas temperature, the wavelength of the laser signal after the modulation that the Laser output hair of the first laser generator 104 and the second laser generator 105 goes out is locked in respectively the Absorption Line center v of the first locking channel 101 and the second locking channel 113 target molecule sample cell of living in target molecule ₀₁And v ₀₂Place.Temperature according to analog to digital conversion outcome measurement measured target gas is specially:

The analog to digital conversion result of supposing 112 pairs of detectors that collect 108 of control device, 109,118 and 119 laser signals that detect is respectively I ₅, I ₆, I ₇And I ₈, the ratio of transformation result is the laser signal that goes out of the Laser output hair of the first laser generator 104 and the second laser generator 105 at the absorption peak of Absorption Line center than R, namely absorption peak is R=(I than R ₅/ I ₇)/(I ₆/ I ₈).

After the acquisition absorption peak is than R, in conjunction with formula $R=k_{v,1}/k_{v,2}=\frac{S_1\left(T_0\right){\mathrm{\&phi;}}_1\left(v\right)}{S_2\left(T_0\right){\mathrm{\&phi;}}_2\left(v\right)}\exp (-\frac{\mathrm{hc}}{k_B}(E_1^{\&prime;\&prime;}-{\mathrm{<figure-callout\; id="2"\; label="E"\; filenames="HDA00002329673700032.png"\; state="\{\{state\}\}">E</figure-callout>}}_2^{\&prime;\&prime;})(\frac{1}{T}-\frac{1}{T_0}))$ Draw the temperature of gas, wherein: h is the Planck constant, and c is the light velocity, k _BFor Boltzmann constant, T ₀" be state energy levels under transition, S (T for the standard temperature 296K that database uses, E ₀) be absorption line strengths, φ (v) is linear function, widen linear and pressure Lorentz lorentz's type is widened linear convolution and obtained by the Doppler of Gaussian, and linear function meets ∫ φ (v) dv=1.

Above-mentioned when obtaining absorption peak than R, control device 112 can gather the laser signal in two sample measurement channel and reference channel simultaneously, and the laser signal in reference channel is used for correcting sample and measures the impact of Atmospheric Absorption on laser signal in passage, therefore the above-mentioned method of obtaining peakedness ratio R has improved peakedness ratio R precision, further improves overall measurement accuracy.

When measuring the concentration of measured target gas, the wavelength of the laser after the modulation that the Laser output hair of the first laser generator 104 goes out is locked in the Absorption Line center v of target molecule in the first locking channel 101 target molecule sample cell of living in ₀₁Place.Concentration according to analog to digital conversion outcome measurement measured target gas is specially:

The analog to digital conversion result of supposing 112 pairs of detectors that collect 108 of control device, 109,118 and 119 laser that detect is respectively I ₅, I ₆, I ₇And I ₈, the ratio of transformation result is that laser after the modulation that goes out of the Laser output hair of the first laser generator 104 is at Absorption Line center v ₀₁The peak value H at place, namely the absorption peak H of laser in the Absorption Line center that go out of the Laser output hair of the first laser generator 104 is H=(I ₅/ I ₇)/(I ₆/ I ₈).

After obtaining absorption peak H, in conjunction with formula

Draw the concentration of measured target gas, wherein: H is absorption peak, P is the general pressure of all gas in sample pond 123, L is the length of the light path of laser signal in sample pond 123, can directly measure, φ (v) is linear function, by the Doppler of Gaussian, widens linear and pressure Lorentz lorentz's type is widened linear convolution and obtained, and linear function meets ∫ φ (v) dv=1, and S (T) is absorption line strengths.

The curve map of the measured target gas temperature that the foundation system of utilizing laser spectrum measurement gas parameter shown in Figure 3 is measured as shown in Figure 4.Fig. 5 is the gas temperature curve map that the scanning wavelength method is measured, and wherein: the horizontal ordinate of Fig. 5 is experiment number.Fig. 4 and Fig. 5 are for selecting the Liang Tiao center to lay respectively at the Absorption Line of 1365.03nm and 1397.08nm according to HITRAN2008, and pressure P is to record under 9600Pa, normal temperature.Adopting simultaneously semiconductor thermometer gas-monitoring temperature is 295 ± 1K.

Draw from above-mentioned two curve maps, the embodiment of the present application is disclosed, and to utilize the measured target gas temperature that the system of laser spectrum measurement gas parameter is measured be 296 ± 1K, and measuring speed is 400kHz, and the single-point response time is 2.5 μ s.The measured target gas temperature that the scanning wavelength method is measured is high in 1-10Hz low speed accuracy of measurement, and when the 100Hz velocity survey, accuracy of measurement is low.

Need to prove: the temperature survey uncertainty of scanning wavelength method is:

And the temperature survey inaccuracy of the application's system is:

Utilize the integration absorptance of experiment measuring and the relative error of peak height absorptance

Can extrapolate the measuring error that adopts different measuring method temperature.Clearly, while adopting the application to measure temperature, two linear functions compare relative error

Also can cause the temperature survey deviation.Therefore the application is more strict to the right selection of Absorption Line, and need to meet the following conditions: Absorption Line is comparatively isolated; Absorptivity is not less than 5%; Article two, the lower state energy level difference of Absorption Line is enough large; Article two, the self collision of Absorption Line is widened coefficient gamma _Self, air collision broadening coefficient gamma _airAnd temperature dependent coefficient n _airApproximate identical; The air pressure displacement δ of Absorption Line _airAs far as possible little.

The application technique scheme, avoided the impact of the laser signal after modulation that sample measurement channel sample of living in pond 123 goes out the Laser output hair, improves measuring accuracy.

Above-mentioned Fig. 1 is to the system of utilizing laser spectrum measurement gas parameter shown in Figure 3, locking device 111 and 115 structural representation are as shown in Figure 6, comprise: lock-in amplifier 120 and PID (Proportion Integration Differentiation, proportion integration differentiation) amplifier 121;

Lock-in amplifier 120, be used for the laser signal that pick-up probe detects, and the signal that the laser signal basis signal generator 106 that detects is produced carries out demodulation, and the signal after demodulation is sent.The laser signal that lock-in amplifier 120 pick-up probes 107 in locking device 111 detect, the laser signal that lock-in amplifier 120 pick-up probes 114 in locking device 115 detect.

PID amplifier 121, for the signal after the demodulation that receives lock-in amplifier 120 transmissions, signal after demodulation is carried out proportional integral to be amplified, generate feedback control signal, control laser power controller, the Absorption Line center of wavelength target molecule in locking channel target molecule sample cell of living in of the laser signal after the modulation that goes out with locking Laser output hair.

Above-mentioned Fig. 1 is the semiconductor diode laser delivery to Laser output head in the system of utilizing laser spectrum measurement gas parameter shown in Figure 3, and detector is the InGaAs infrared eye that bandwidth is 10MHz.

Embodiment is corresponding with said system, and the embodiment of the present application also discloses a kind of method of utilizing laser spectrum measurement gas parameter, and process flow diagram as shown in Figure 7, comprising:

S101: laser power controller receives the signal that signal generator produces, and the laser signal of the first-born one-tenth of Laser output is modulated, and the laser signal after modulation is gone out by the Laser output hair.

S102: the laser signal that the locking device pick-up probe detects, the signal that the laser signal basis signal generator that detects is produced carries out demodulation, generate feedback control signal, control the laser power controller in the first laser generator, the Absorption Line center v of wavelength target molecule in the first locking channel target molecule sample cell of living in of the laser signal after the modulation that goes out with locking Laser output hair ₀₁Place, wherein the laser signal that detects of detector is to enter the laser signal that the Laser output hair in the first laser generator of receiving light path device and the first locking channel goes out;

S103: control device gathers the laser signal that detector detects, the laser signal that collects is carried out analog to digital conversion, concentration according to analog to digital conversion outcome measurement measured target gas, the laser signal that detector detects is to enter the laser signal that the Laser output hair in the first laser generator of receiving light path device and sample measurement channel goes out, and enters the laser signal that the Laser output hair in the second laser generator of sample measurement channel goes out.

The method of utilizing laser spectrum measurement gas parameter shown in Figure 8, on Fig. 7 basis, realize the measured target gas thermometry, also comprises:

S104: the laser signal that the locking device pick-up probe detects, the signal that the laser signal basis signal generator that detects is produced carries out demodulation, generate feedback control signal, control the laser power controller in the second laser generator, the Absorption Line center v of wavelength target molecule in described the second locking channel target molecule sample cell of living in of the laser signal after the modulation that goes out with locking Laser output hair ₀₂Place, wherein the laser signal that detects of detector is to enter the laser signal that the Laser output hair in the second laser generator of receiving light path device and the second locking channel goes out;

S105: control device gathers the laser signal that detector detects, the laser signal that collects is carried out analog to digital conversion, according to the temperature of analog to digital conversion outcome measurement measured target gas, the laser signal that detector detects is the laser signal that enters described receiving light path device and described sample measurement channel.

Wherein: the concentration according to analog to digital conversion outcome measurement measured target gas is specially:

Obtain laser signal that in the first laser generator, the Laser output hair the goes out absorption peak in target molecule Absorption Line center according to the analog to digital conversion result;

In conjunction with formula

Draw the concentration of measured target gas, wherein: H is absorption peak, P is the general pressure of all gas in sample pond 123, can measure by pressure transducer, L is the length of the light path of laser signal in sample pond 123, can directly measure, φ (v) is linear function, and S (T) is absorption line strengths.

Temperature according to analog to digital conversion outcome measurement measured target gas is specially: according to the analog to digital conversion result, obtain laser signal after modulation that in the first laser generator and the second laser generator, the Laser output hair goes out respectively at two Absorption Line center v of target molecule ₀₁And v ₀₂The absorption peak ratio at place;

In conjunction with formula $R=k_{v,1}/k_{v,2}=\frac{S_1\left(T_0\right){\mathrm{\&phi;}}_1\left(v\right)}{S_2\left(T_0\right){\mathrm{\&phi;}}_2\left(v\right)}\exp (-\frac{\mathrm{hc}}{k_B}(E_1^{\&prime;\&prime;}-{\mathrm{<figure-callout\; id="2"\; label="E"\; filenames="HDA00002329673700032.png"\; state="\{\{state\}\}">E</figure-callout>}}_2^{\&prime;\&prime;})(\frac{1}{T}-\frac{1}{T_0}))$ Draw the temperature of measured target gas, wherein: h is the Planck constant, and c is the light velocity, k _BFor Boltzmann constant, T ₀" be state energy levels under transition, S (T for the standard temperature 296K that database uses, E ₀) be absorption line strengths, φ (v) is the function of linear function, widen linear and pressure Lorentz lorentz's type is widened linear convolution and obtained by the Doppler of Gaussian, and linear function meets ∫ φ (v) dv=1.

The concrete enforcement of the step of said method embodiment sees also the related description in system embodiment, and this is no longer set forth.

Each embodiment in this instructions all adopts the mode of going forward one by one to describe, between each embodiment, identical similar part is mutually referring to getting final product, each embodiment stresses is difference with other embodiment, those of ordinary skills in the situation that do not pay creative work, namely can understand and implement.

The above is only the application's embodiment; should be pointed out that for those skilled in the art, under the prerequisite that does not break away from the application's principle; can also make some improvements and modifications, these improvements and modifications also should be considered as the application's protection domain.

Claims (10)

1. system of utilizing laser spectrum measurement gas parameter, it is characterized in that, comprise: the first locking channel (101), the first sample measurement channel (102), the second sample measurement channel (103), the first laser generator, the second laser generator, signal generator, the first detector (107), the second detector (108), the 3rd detector (109), receiving light path device, the first locking device (111) and control device, wherein:

Described the first laser generator and described the second laser generator comprise laser power controller and Laser output head, described laser power controller is used for receiving the signal that described signal generator produces, laser signal to the first-born one-tenth of described Laser output is modulated, and the laser signal after modulation is gone out by described Laser output hair;

Described the first locking device (111), be used for receiving the laser signal that described the first detector (107) detects, the laser signal that detects is carried out demodulation according to the signal that described signal generator produces, generate feedback control signal, control the laser power controller of the first laser generator, the Absorption Line center v of wavelength signals target molecule in described the first locking channel (101) target molecule sample cell of living in of the laser after the modulation that goes out with the Laser output hair that locks the first laser generator ₀₁Place, the wherein laser signal that goes out for the Laser output hair in the first laser generator that enters described receiving light path device and the first locking channel (101) of the laser signal that detects of the first detector (107);

described control device, be used for gathering respectively the laser signal that described the second detector (108) and the 3rd detector (109) detect, the laser signal that collects is carried out analog to digital conversion, concentration according to analog to digital conversion outcome measurement measured target gas, the laser signal that the laser signal that the second detector (108) detects goes out for the Laser output hair in the first laser generator that enters described receiving light path device and described the first sample measurement channel (102), the laser signal that the laser signal that the 3rd detector (109) detects goes out for the Laser output hair in the second laser generator that enters described the second sample measurement channel (103).

2. the system of utilizing laser spectrum measurement gas parameter according to claim 1, is characterized in that, described receiving light path device comprises: the first beam splitter and the first catoptron; Laser signal after the modulation that described the first beam splitter goes out the Laser output hair in described the first laser generator is divided into reflected light signal and optical signal transmissive, wherein reflected light signal enters described the first sample measurement channel (102) through described the first mirror reflects, and optical signal transmissive enters described the first locking channel (101).

3. the system of utilizing laser spectrum measurement gas parameter according to claim 2, is characterized in that, also comprises: the second locking channel (113);

Described receiving light path device also comprises: the second beam splitter and the second catoptron; Laser signal after the modulation that described the second beam splitter goes out the Laser output hair in described the second laser generator is divided into reflected light signal and optical signal transmissive, wherein reflected light signal enters described the second locking channel (113) through described the second mirror reflects, and optical signal transmissive enters described the second sample measurement channel (103).

4. the system of utilizing laser spectrum measurement gas parameter according to claim 3, is characterized in that, also comprises: the 4th detector (114) that is connected with described the second locking channel (113) and the second locking device (115);

Described the second locking device (115), be used for receiving the laser signal that described the 4th detector (114) detects, the laser signal that detects is carried out demodulation according to the signal that described signal generator produces, generate feedback control signal, control the laser power controller of the second laser generator, the Absorption Line center v of wavelength target molecule in described the second locking channel (113) target molecule sample cell of living in of the laser signal after the modulation that goes out with the Laser output hair that locks the second laser generator ₀₂Place, the wherein laser signal that goes out for the Laser output hair in the second laser generator that enters described receiving light path device and the second locking channel (113) of the laser signal that detects of the 4th detector (114);

described control device, also be used for gathering respectively the laser signal that described the second detector (108) and the 3rd detector (109) detect, the laser signal that collects is carried out analog to digital conversion, temperature according to analog to digital conversion outcome measurement measured target gas, wherein, the laser signal that the second detector (108) detects goes out for the Laser output hair by the first laser generator, enter the laser signal of receiving light path device and the first sample measurement channel (102), the laser signal that the 3rd detector (109) detects is that the Laser output hair of the second laser generator goes out, enter the laser signal of receiving light path device and the second sample measurement channel (103).

5. the system of utilizing laser spectrum measurement gas parameter according to claim 4, is characterized in that, also comprises: the first reference channel (116) and the second reference channel (117);

Described receiving light path device also comprises: the 3rd beam splitter and the 4th beam splitter;

The reflected light signal of described the first beam splitter is reflected light signal and optical signal transmissive through described the 3rd beam splitter beam splitting, the reflected light signal of the 3rd beam splitter enters the first reference channel (116), and the optical signal transmissive of the 3rd beam splitter is received by described the first catoptron;

The reflected light signal of described the second beam splitter is reflected light signal and optical signal transmissive through described the 4th beam splitter beam splitting, the reflected light signal of the 4th beam splitter enters the second reference channel (117), and the optical signal transmissive of the 4th beam splitter is received by described the second catoptron.

6. the system of utilizing laser spectrum measurement gas parameter according to claim 5, it is characterized in that, also comprise: the 5th detector (118) that is connected with described the first reference channel (116), the 6th detector (119) that is connected with described the second reference channel (117);

described control device, also be used for gathering respectively described the second detector (108), the 3rd detector (109), the laser signal that the 5th detector (118) and the 6th detector (119) detect, the laser signal that collects is carried out analog to digital conversion, according to the temperature of analog to digital conversion outcome measurement measured target gas and the concentration of measured target gas, wherein the laser signal that detects of the 5th detector (118) is for entering the laser signal of receiving light path device and the first reference channel (116), the laser signal that the 6th detector (119) detects is for entering the laser signal of receiving light path device and the second reference channel (117), the laser signal that the second detector (108) detects is for entering the laser signal of receiving light path device and the first sample measurement channel (102), the laser signal that the 3rd detector (109) detects is for entering the laser signal of receiving light path device and the second sample measurement channel (103).

7. the described system of utilizing laser spectrum measurement gas parameter of according to claim 4 to 6 any one, it is characterized in that, described the first locking device (111) and the second locking device (115) comprise respectively: lock-in amplifier and proportion integration differentiation PID amplifier;

Described lock-in amplifier, be used for the laser signal that pick-up probe detects, and the laser signal that detects is carried out demodulation according to the signal that described signal generator produces, and the signal after demodulation is sent;

Described PID amplifier, for the signal after the demodulation that receives described lock-in amplifier transmission, signal after described demodulation is carried out proportional integral to be amplified, generate feedback control signal, control described laser power controller, with the Absorption Line center of wavelength target molecule in described locking channel target molecule sample cell of living in of locking the laser signal after the modulation that described Laser output hair goes out.

8. a method of utilizing systematic survey gas parameter claimed in claim 1, is characterized in that, comprising:

The laser power controller of the first laser generator receives the signal that signal generator produces, and the laser signal of the first-born one-tenth of Laser output of the first laser generator is modulated, and the laser signal after modulation is gone out by the Laser output hair of the first laser generator;

The laser power controller of the second laser generator receives the signal that signal generator produces, and the laser signal of the first-born one-tenth of Laser output of the second laser generator is modulated, and the laser signal after modulation is gone out by the Laser output hair of the second laser generator;

The first locking device (111) receives the laser signal that the first detector (107) detects, the signal that the laser signal basis signal generator that detects is produced carries out demodulation, generate feedback control signal, control the laser power controller of the first laser generator, the Absorption Line center v of wavelength target molecule in the first locking channel (101) target molecule sample cell of living in of the laser signal that goes out with the Laser output hair that locks the first laser generator ₀₁Place, the wherein laser signal that goes out for the Laser output hair in the first laser generator that enters receiving light path device and the first locking channel (101) of the laser signal that detects of the first detector (107);

control device gathers respectively the laser signal that the second detector (108) and the 3rd detector (109) detect, the laser signal that collects is carried out analog to digital conversion, concentration according to analog to digital conversion outcome measurement measured target gas, the laser signal that the laser signal that the second detector (108) detects goes out for the Laser output hair in the first laser generator that enters receiving light path device and the first sample measurement channel (102), the laser signal that the laser signal that the 3rd detector (109) detects goes out for the Laser output hair in the second laser generator that enters the second sample measurement channel (103).

9. method according to claim 8, is characterized in that, also comprises:

The second locking device (115) receives the laser signal that the 4th detector (114) detects, the signal that the laser signal basis signal generator that detects is produced carries out demodulation, generate feedback control signal, control the laser power controller of the second laser generator, the Absorption Line center v of wavelength target molecule in the second locking channel (113) target molecule sample cell of living in of the laser signal that goes out with the Laser output hair that locks the second laser generator ₀₂Place, the wherein laser signal that goes out for the Laser output hair in the second laser generator that enters receiving light path device and the second locking channel (113) of the laser signal that detects of the 4th detector (114);

control device gathers respectively the laser signal that the second detector (108) and the 3rd detector (109) detect, the laser signal that collects is carried out analog to digital conversion, temperature according to analog to digital conversion outcome measurement measured target gas, wherein, the laser signal that the second detector (108) detects goes out for the Laser output hair by the first laser generator, enter the laser signal of receiving light path device and the first sample measurement channel (102), the laser signal that the 3rd detector (109) detects is that the Laser output hair of the second laser generator goes out, enter the laser signal of receiving light path device and the second sample measurement channel (103).

10. method according to claim 9, is characterized in that, described concentration according to analog to digital conversion outcome measurement measured target gas is specially:

Obtain laser signal that the Laser output hair of the first laser generator the goes out absorption peak H in the Absorption Line center according to the analog to digital conversion result;

In conjunction with formula

Draw the concentration of measured target gas, wherein: H is absorption peak, P is the general pressure of all gas in the sample pond, L is the length of the light path of laser signal in the sample pond, φ (v) is linear function, and linear function meets ∫ φ (v) dv=1, and S (T) is absorption line strengths;

Temperature according to analog to digital conversion outcome measurement measured target gas is specially: according to the analog to digital conversion result, obtain laser signal that in the first laser generator and the second laser generator, the Laser output hair goes out respectively at target molecule Absorption Line center v ₀₁And v ₀₂The absorption peak at place compares R;

In conjunction with formula $R=k_{v,1}/k_{v,2}=\frac{S_1\left(T_0\right)\mathrm{\&phi;}\left(v\right)}{S_2\left(T_0\right){\mathrm{\&phi;}}_2\left(v\right)}\exp (-\frac{\mathrm{hc}}{k_B}(E_1^{\&prime;\&prime;}-E_2^{\&prime;\&prime;})(\frac{1}{T}-\frac{1}{T_0}))$ Draw the temperature of measured target gas, wherein: h is the Planck constant, and c is the light velocity, k _BFor Boltzmann constant, T ₀" be state energy levels under transition, S (T for the standard temperature 296K that database uses, E ₀) be absorption line strengths, φ (v) is linear function, and linear function meets ∫ φ (v) dv=1.

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