CN104165847B - The device of synchro measure liquid film concentration and thickness and measuring method - Google Patents

Abstract

The present invention provides the device of a kind of synchro measure liquid film concentration and thickness, it is characterised in that, comprising: two LASER Light Source, send the laser light beam that wavelength is different; Wavelength division multiplexer, is connected with two LASER Light Source, is coupled into a branch of by two bundle laser light beams; First collimator, is connected with wavelength division multiplexer, is focused on by laser light beam; Carrier of liquid membrane, is arranged on immediately below first collimator; 2nd collimator, is arranged on immediately below Carrier of liquid membrane, for collecting the laser light beam through Carrier of liquid membrane, line focusing of going forward side by side; Channel-splitting filter, is connected with the 2nd collimator, and laser light beam is divided into the two bundle laser light beams that wavelength is different; Two spectra collection components, are connected with channel-splitting filter respectively, receive and measure the intensity of every Shu Jiguang light beam that this channel-splitting filter separates; And computer, it being connected with two spectra collection components respectively, the intensity of the laser light beam recorded by two spectra collection components processes, and calculates concentration and the one-tenth-value thickness 1/10 of liquid film to be measured.

Description

The device of synchro measure liquid film concentration and thickness and measuring method

Technical field

The present invention relates to measuring apparatus and measuring method, it is specifically related to a kind of measuring apparatus based on Beer-Lambert law, on-line synchronous measurement liquid film concentration and thickness and measuring method.

Background technology

In various commercial run, the phenomenon that droplet impact forms liquid film to solid surface extensively exists, as formed urea soln liquid film etc. on vehicle vent gas discharging pipe in SCR (SCR) system. Liquid film carries out quantitative analysis can not only understand the formation of liquid film better and evaporate the essence of this extremely complicated physical process, and have very important significance to optimizing the various commercial runs involved by liquid film.

The constituent concentration of solution thickness of liquid film and liquid film inside is closely related, and in the research to liquid film, these parameters are often coupled mutually, sets up to model and solves and brings difficulty. Traditional measuring method can only realize the measurement of single parameter in the concentration to liquid film or thickness, the concentration of liquid film and these two important indicators of thickness in cannot measuring simultaneously.

Summary of the invention

The present invention be directed to what the problems referred to above carried out, object is that providing a kind of can go out the concentration of solution liquid film and the device of thickness and measuring method by Simultaneously test.

The present invention for achieving the above object, have employed following technical scheme:

The present invention provides the device of a kind of synchro measure liquid film concentration and thickness, it is characterised in that, comprising: two LASER Light Source, for sending the different laser light beam of wavelength; Wavelength division multiplexer, is connected with two LASER Light Source, and the two bundle laser light beams two LASER Light Source sent are coupled into a branch of; First collimator, is connected with wavelength division multiplexer, is focused on by the laser light beam of wavelength division multiplexer coupling; Carrier of liquid membrane, is arranged on immediately below first collimator, and for carrying liquid film to be measured, the laser light beam sent after first collimator is focused on is through liquid film to be measured; 2nd collimator, is arranged on immediately below Carrier of liquid membrane, for collecting the laser light beam through Carrier of liquid membrane, and is focused on by this laser light beam; Channel-splitting filter, is connected with the 2nd collimator, and the laser light beam sent after the 2nd collimator being focused on is divided into two different bundle laser light beams of wavelength; Two spectra collection components, are connected with channel-splitting filter respectively, receive and measure the intensity of every Shu Jiguang light beam that this channel-splitting filter separates; And computer, it being connected with two spectra collection components respectively, the intensity of the laser light beam recorded by two spectra collection components processes, and calculates concentration and the one-tenth-value thickness 1/10 of liquid film to be measured.

Synchro measure liquid film concentration provided by the present invention and the device of thickness, it is also possible to having such feature: wherein, LASER Light Source is semiconductor laser, and spectra collection component is photodetector.

The present invention also provides a kind of and adopts the device of above-mentioned synchro measure liquid film concentration and thickness to measure the method for liquid film concentration and thickness, it is characterized in that, comprise the following steps: step one, employing absorption spectrum measuring apparatus measures the absorption spectrum of the solution liquid film of some different concns, and the solution liquid film obtaining different concns is to the uptake factor of the light of different wave number; Step 2, the solution liquid film comparing different concns, to the uptake factor of the light of different wave number, selects two wave number ��₁And ��₂, make the solution liquid film of different concns be �� to wave number₁The uptake factor difference of light minimum, make the solution liquid film of different concns be �� to wave number₂The uptake factor difference of light maximum; Step 3, respectively at two wave number ��₁And ��₂Under, the concentration of the uptake factor corresponding to the solution liquid film of different concns and solution liquid film is made linear fit, obtains following equation: K_i=A_i+B_iC, i=1,2, K in formula_iWave number is �� by the solution liquid film of to be concentration be c_iThe uptake factor of light, c is the concentration of solution liquid film, A_iAnd B_iIt it is fitting coefficient; Step 4, arranges the Carrier of liquid membrane without liquid film, regulates two LASER Light Source, and making two LASER Light Source export wave number respectively is ��₁And ��₂Laser light beam, adopting two spectra collection components to measure wave number after the Carrier of liquid membrane without liquid film respectively is ��₁And ��₂The intensity of laser light beam, as background light intensity I_0i(i=1,2); Step 5, load liquid film to be measured on Carrier of liquid membrane, adopting two spectra collection components to measure wave number after the Carrier of liquid membrane of load liquid film to be measured respectively is ��₁And ��₂The intensity of laser light beam, as transmitted light intensity I_ti(i=1,2); Step 6, adopts computer to collect background light intensity I_0iAnd transmitted light intensity I (i=1,2)_ti(i=1,2), row data of going forward side by side processes, and according to Beer-Lambert law, transmissivity is represented and is:T in formula_iBeing transmissivity, d is the thickness of liquid film to be measured, and calculating liquid film to be measured to wave number is ��₁And ��₂The logarithmic ratio of transmissivity of laser light beam $R_{1/2}:R_{1/2}=\frac{\lg T_1}{\lg T_2}=\frac{\lg (I_{t1}/I_{01})}{\lg (I_{t2}/I_{02})}=\frac{-K_{1}d}{-K_{2}d}=\frac{K_1}{K_2},$ According to K_i=A_i+B_iC, can by the logarithmic ratio R of transmissivity_1/2Expression isThe then concentration of liquid film to be measuredThe thickness of liquid film to be measured $d=\frac{\lg (I_{01}/I_{t1})}{A_1+B_1\frac{A_2{R}_{1/2}-A_1}{B_1-B_2{R}_{1/2}}}=\frac{\lg (I_{02}/I_{t2})}{A_2+B_2\frac{A_2{R}_{1/2}-A_1}{B_1-B_2{R}_{1/2}}}.$

The effect of invention and effect

According to the device of synchro measure liquid film concentration involved in the present invention and thickness, because two LASER Light Source can send two different bundle laser light beams of wavelength respectively, two spectra collection components measure the intensity of the two bundle transmission laser light beams that channel-splitting filter sends respectively, and it is transferred to computer, computer calculate obtains concentration value and the one-tenth-value thickness 1/10 of liquid film, therefore can measure concentration and these two important parameters of thickness of fluid film simultaneously. In addition, because laser light beam can be focused on by arranging of two collimators, increase the intensity of the laser light beam through liquid film, therefore, it is possible to realize the measurement of high precision.

Accompanying drawing explanation

Fig. 1 is the device of synchro measure liquid film concentration and thickness;

Fig. 2 is wave number ��₁Lower uptake factor-mass concentration graphic representation; And

Fig. 3 is wave number ��₂Lower uptake factor-mass concentration graphic representation.

Embodiment

Below in conjunction with accompanying drawing, device and the measuring method of synchro measure liquid film concentration provided by the present invention and thickness are elaborated.

<embodiment one>

Fig. 1 is the device of synchro measure liquid film concentration and thickness.

As shown in Figure 1, the device 10 of synchro measure liquid film concentration and thickness comprises LASER Light Source 11, LASER Light Source 12, wavelength division multiplexer 13, first collimator 14, Carrier of liquid membrane 15, the 2nd collimator 16, channel-splitting filter 17, spectra collection component 18, spectra collection component 19 and computer 20.

In the present embodiment, LASER Light Source 11 is semiconductor laser 11, and LASER Light Source 12 is semiconductor laser 12. Wavelength division multiplexer 13 is connected with semiconductor laser 12 with semiconductor laser 11 respectively. First collimator 14 is connected with wavelength division multiplexer 13. Carrier of liquid membrane 15 is arranged on immediately below first collimator 14, and in the present embodiment, Carrier of liquid membrane 15 is silica glass. 2nd collimator 16 is arranged on the underface of Carrier of liquid membrane 15. Channel-splitting filter 17 is connected with the 2nd collimator 16. Spectra collection component 18 is photodetector 18, and spectra collection component 19 is photodetector 19, and photodetector 18 is connected with channel-splitting filter 17 respectively with photodetector 19. Computer 20 is connected with photodetector 19 with photodetector 18 respectively.

Semiconductor laser 11 is respectively used to semiconductor laser 12 send two different bundle laser light beams of wavelength, and two bundle laser light beams are coupled into a branch of by wavelength division multiplexer 13, then through Carrier of liquid membrane 15 after first collimator 14 focuses on. Laser light beam through Carrier of liquid membrane 15 is focused on by the 2nd collimator 16, then the laser light beam after focusing is divided into two different bundle laser light beams of wavelength by channel-splitting filter 17, the two bundle laser light beams that channel-splitting filter 17 sends collected respectively by photodetector 18 and photodetector 19, the intensity of measuring laser beam, and it is transferred to computer 20. Computer 20, for carrying out data processing, calculates concentration and the one-tenth-value thickness 1/10 of fluid film.

<embodiment two>

The method of synchro measure liquid film concentration and thickness is as follows:

Step one, get pure water and mass concentration be respectively 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50% urea soln liquid film, adopt absorption spectrum measuring apparatus to measure pure water and above-mentioned urea soln liquid film respectively at 6000��8000cm^-1Uptake factor under wave number.

Step 2, maps the uptake factor of pure water and all urea solution films to wave number value, and be absorbed coefficient-wave number curve, the uptake factor value of all urea solution films under comparing different wave number, selects the wave number �� making the uptake factor difference of all urea solution films minimum₁=6719.75cm^-1, and the wave number �� that the uptake factor difference making all urea solution films is maximum₂=7040.75cm^-1��

Step 3, gets pure water and all urea soln liquid films at wave number ��₁Under uptake factor value, by uptake factor value to liquid film concentration mapping, the coefficient that is absorbed-mass concentration graphic representation,

Fig. 2 is wave number ��₁Lower uptake factor-mass concentration graphic representation.

As shown in Figure 2, wave number is �� by liquid film₁=6719.75cm^-1The uptake factor of light and the mass concentration of liquid film linear, make linear fit and can obtain K₁=0.0061c+10.927, K in formula₁Be the urea soln liquid film of different concns it is �� to wave number₁The uptake factor of light, c is the mass concentration of urea soln liquid film.

Get pure water and and all urea soln liquid films at wave number ��₂Under uptake factor value, by uptake factor value to liquid film concentration mapping, obtain wave number ��₂Under liquid film uptake factor-mass concentration graphic representation,

Fig. 3 is wave number ��₂Lower uptake factor-mass concentration graphic representation.

As shown in Figure 3, it is �� in wave number₂=7040.75cm^-1Time, the uptake factor of light is linearly increased by urea soln liquid film with liquid film quality concentration, uptake factor and liquid film quality concentration is done linear fit and can obtain K₂=-0.1014c+12.294, K in formula₂Be the urea soln liquid film of different concns it is �� to wave number₂The uptake factor of light, c is the mass concentration of urea soln liquid film.

Step 4, arranges empty silica glass as Carrier of liquid membrane 15, opens semiconductor laser 11 and semiconductor laser 12, regulate two semiconductor lasers, and the laser light beam wave number that semiconductor laser 11 and semiconductor laser 12 are sent is respectively ��₁=6719.75cm^-1And ��₂=7040.75cm^-1. Adopting photodetector 18 and photodetector 19 to measure wave number after Carrier of liquid membrane 15 respectively is ��₁And ��₂Two bundle laser light beams intensity I₀₁And I₀₂, as background light intensity.

Step 5, needle-like dropper is adopted to draw urea soln to be measured, squeeze on Carrier of liquid membrane 15, form urea soln liquid film, keeping the output wavelength of semiconductor laser 11 and semiconductor laser 12 constant, adopting photodetector 18 and photodetector 19 to measure through being loaded with wave number after the Carrier of liquid membrane 15 of urea solution film respectively is ��₁And ��₂Two bundle laser light beams intensity I_t1And I_t2, as transmitted light intensity.

Step 6, according to Beer-Lambert law, represents transmissivity and is:T in formula_iBeing transmissivity, d is the thickness of urea solution film to be measured.

Calculating urea solution film to be measured to wave number is ��₁And ��₂The logarithmic ratio of transmissivity of laser light beam $R_{1/2}:R_{1/2}=\frac{\lg T_1}{\lg T_2}=\frac{\lg (I_{t1}/I_{01})}{\lg (I_{t2}/I_{02})}=\frac{-K_{1}d}{-K_{2}d}=\frac{K_1}{K_2},$ Because K₁=0.0061c+10.927, K₂=-0.1014c+12.294, therefore can by the logarithmic ratio R of transmissivity_1/2Expression is: $R_{1/2}=\frac{K_1}{K_2}=\frac{A_1+B_1}{A_2+B_2}.$

The concentration of liquid film to be measured is can be obtained fom the above equation:

$c=\frac{-0.1014R_{1/2}-0.0061}{10.927-12.294R_{1/2}}=\frac{0.1014\lg (I_{t1}/I_{01})+0.0061}{12.294\lg (I_{t2}/I_{t1})-10.927},$

The then thickness of liquid film to be measured $d=\frac{\lg (I_{01}/I_{t1})}{0.0061c+10.927}=\frac{\lg (I_{02}/I_{t2})}{-0.1014c+12.294}.$

The effect of embodiment and effect

Synchro measure liquid film concentration involved by embodiment one and the device 10 of thickness, because semiconductor laser 11 can send two different bundle laser light beams of wavelength respectively with semiconductor laser 12, photodetector 18 and photodetector 19 can measure the intensity of the two bundle transmission laser light beams that channel-splitting filter 17 sends respectively, and it is transferred to computer 20, computer 20 can calculate concentration value and the one-tenth-value thickness 1/10 of liquid film, and therefore this device can measure concentration and these two important parameters of thickness of fluid film simultaneously. In addition, because laser light beam can be focused on by collimator 14 and arranging of collimator 16, increasing the intensity of the laser light beam through liquid film, therefore, this device can realize the measurement of high precision.

The synchro measure liquid film concentration provided according to embodiment two and the method for thickness, because wave number is 6000��8000cm by the urea solution film adopting absorption spectrum measuring apparatus to measure different mass concentration respectively^-1The uptake factor of light, the uptake factor that comparison liquid film quality concentration causes is poor, chooses the wave number value �� that difference is minimum respectively₁The wave number value �� maximum with difference₂, simulate wave number ��₁And ��₂The linear equation of lower uptake factor and liquid film quality concentration, then adopting the synchro measure liquid film concentration of embodiment one offer and the device 10 of thickness to measure wave number is ��₁And ��₂Laser through the light intensity after liquid film to be measured, liquid film to be measured is to the transmitance of two bundle laser light beams to impose business to draw with bias light, and then concentration value and the one-tenth-value thickness 1/10 of liquid film to be measured is calculated according to above-mentioned linear equation, therefore, the method conveniently can synchronously calculate concentration and the thickness of liquid film to be measured, has very strong practical value.

Certainly, synchro measure liquid film concentration involved in the present invention and the device of thickness and measuring method, be not merely defined in the content described in above embodiment. These are only the basic explanation under present inventive concept, and according to any equivalent transformation that the technical scheme of the present invention is done, protection scope of the present invention all should be belonged to.

Claims (2)

1. measuring a method for liquid film concentration and thickness, adopt the device of synchro measure liquid film concentration and thickness to carry out, described device comprises: two LASER Light Source, for sending the different laser light beam of wavelength; Wavelength division multiplexer, is connected with two described LASER Light Source, and the two described laser light beams of bundle two described LASER Light Source sent are coupled into a branch of; First collimator, is connected with described wavelength division multiplexer, and the laser light beam being coupled by described wavelength division multiplexer focuses on; Carrier of liquid membrane, is arranged on immediately below described first collimator, and for carrying liquid film to be measured, the laser light beam sent after described first collimator is focused on is through described liquid film to be measured; 2nd collimator, is arranged on immediately below described Carrier of liquid membrane, for collecting the laser light beam through described Carrier of liquid membrane, and is focused on by this laser light beam; Channel-splitting filter, is connected with described 2nd collimator, and the laser light beam sent after described 2nd collimator being focused on is divided into two different bundle laser light beams of wavelength; Two spectra collection components, are connected with described channel-splitting filter respectively, receive and measure the intensity of every Shu Suoshu laser light beam that this channel-splitting filter separates; And computer, spectra collection component described with two is connected respectively, the intensity of the described laser light beam that two described spectra collection components record is processed, and calculates concentration and the one-tenth-value thickness 1/10 of described liquid film to be measured; It is characterized in that, comprise the following steps:

Step one, employing absorption spectrum measuring apparatus measures the absorption spectrum of the solution liquid film of some different concns, and the solution liquid film obtaining described different concns is to the uptake factor of the light of different wave number;

Step 2, the solution liquid film comparing described different concns, to the uptake factor of the light of different wave number, selects two wave number ��₁And ��₂, make the solution liquid film of described different concns be �� to wave number₁The uptake factor difference of light minimum, make the solution liquid film of described different concns be �� to wave number₂The uptake factor difference of light maximum;

Step 3, respectively at two described wave number ��₁And ��₂Under, the concentration of the uptake factor corresponding to the solution liquid film of described different concns and described solution liquid film is made linear fit, obtains following equation: K_i=A_i+B_iC, i=1,2, K in formula_iWave number is �� by the solution liquid film of to be concentration be c_iThe uptake factor of light, c is the concentration of solution liquid film, A_iAnd B_iIt it is fitting coefficient;

Step 4, arranges the described Carrier of liquid membrane without liquid film, regulates two described LASER Light Source, and making two described LASER Light Source export wave number respectively is ��₁And ��₂Laser light beam, adopting two described spectra collection components to measure described wave number after the described Carrier of liquid membrane without liquid film respectively is ��₁And ��₂The intensity of laser light beam, as background light intensity I_0i(i=1,2);

Step 5, load liquid film to be measured on described Carrier of liquid membrane, adopting two described spectra collection components to measure described wave number after the Carrier of liquid membrane of liquid film to be measured described in load respectively is ��₁And ��₂The intensity of laser light beam, as transmitted light intensity I_ti(i=1,2);

Step 6, adopts described computer to collect described background light intensity I_0iAnd described transmitted light intensity I (i=1,2)_ti(i=1,2), row data of going forward side by side processes, and according to Beer-Lambert law, transmissivity is represented and is:T in formula_iBeing transmissivity, d is the thickness of described liquid film to be measured,

Calculating described liquid film to be measured is �� to described wave number₁And ��₂The logarithmic ratio R of transmissivity of laser light beam_1/2: $R_{1/2}=\frac{{\mathrm{lgT}}_1}{{\mathrm{lgT}}_2}=\frac{\lg (I_{t1}/I_{01})}{\lg (I_{t2}/I_{02})}=\frac{-K_{1}d}{-K_{2}d}=\frac{K_1}{K_2},$ According to K_i=A_i+B_iC, can by the logarithmic ratio R of described transmissivity_1/2Expression is

The then concentration of described liquid film to be measured

The thickness of described liquid film to be measured $d=\frac{\lg (I_{01}/I_{t1})}{A_1+B_1\frac{A_2{R}_{1/2}-A_1}{B_1-B_2{R}_{1/2}}}=\frac{\lg (I_{02}/I_{t2})}{A_2+B_2\frac{A_2{R}_{1/2}-A_1}{B_1-B_2{R}_{1/2}}}.$

2. the method for synchro measure liquid film concentration according to claim 1 and thickness, it is characterised in that:

Wherein, described LASER Light Source is semiconductor laser, and described spectra collection component is photodetector.