Homemade solution concentration measurement device based on SPR angle modulation method

Abstract

The invention discloses a self-made solution concentration measuring device based on the SPR angle modulation method, including an operating table, a liftable optical platform mechanism is arranged on the operating table, a transfer plate is arranged on the liftable optical platform mechanism, an angle displacement platform is arranged on the transfer plate, an embedded transparent transfer groove is arranged on the angle displacement platform, a liquid prism is arranged on the transfer groove, and a spectroscope base is arranged on one side of the liftable optical platform mechanism. In the present invention, the liquid prism has the advantages of being able to be repeatedly filled and easy to clean the containing solution, a 0.92 graduation platform is selected, the measurement accuracy can reach 0.3%, the operation is simple, the response time is short, the data import and modification are convenient and fast, and after automatic processing, a clear and intuitive fitting curve, experimental correlation coefficient, relative error and other parameters can be obtained, data evaluation and data visualization are completed, and the measurement accuracy of solution concentration is improved.

Description

Technical Field

[0001] The invention relates to the technical field of solution concentration measurement, and in particular to a self-made solution concentration measurement device based on an SPR angle modulation method. Background Art

[0002] Solution concentration is an important physical quantity that measures the concentration of a solution. It reflects the amount of solute contained in a unit solution. The more solute content, the greater the concentration. Accurately measuring solution concentration has great practical significance for the development of modern industry and agriculture.

[0003] Existing methods for measuring solution concentration include silver nitrate titration, specific gravity, refractometry and conductivity. However, the solution concentrations calculated by these methods have large errors, low precision, and complex operation processes. The solution measurement results are easily affected by various environmental factors, which reduces the accuracy of solution concentration measurement. Summary of the invention

[0004] The purpose of the present invention is to solve the above problems and to propose a self-made solution concentration measuring device based on the SPR angle modulation method.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A self-made solution concentration measuring device based on an SPR angle modulation method comprises an operating table, wherein a liftable optical platform mechanism is arranged on the operating table, an adapter plate is arranged on the liftable optical platform mechanism, an angle displacement platform is arranged on the adapter plate, an embedded transparent adapter slot is arranged on the angle displacement platform, a liquid prism is arranged on the adapter slot, a beam splitter base is arranged on one side of the liftable optical platform mechanism, a polarization beam splitter is arranged on the top of the beam splitter base, a wave plate base is arranged on one side of the beam splitter base, a 1 / 4 wave plate body is arranged on the top of the wave plate base, an analyzer base is arranged on one side of the wave plate base, a linear polarizer is arranged on the top of the analyzer base, a laser base is arranged on one side of the analyzer base, a helium-neon laser is arranged on the top of the laser base, a probe base is also arranged on one side of the liftable optical platform mechanism, a laser probe is arranged on the top of the probe base, and a laser power meter connected to the laser probe is also arranged on one side of the operating table.

[0007] Preferably, the liftable optical platform mechanism includes a lifting frame and a lifting platform, one end of the lifting platform is located inside the lifting frame, and the lifting frame is also provided with a threaded rod and a limit rod passing through the lifting platform, and the top of the lifting platform is also provided with a driving motor connected to the threaded rod.

[0008] Preferably, the measurement range of the laser power meter is 300-900nm.

[0009] Preferably, the helium-neon laser is a linearly polarized laser that produces a wavelength of 635 nm.

[0010] Preferably, the accuracy of the angular displacement platform is 0.92 degrees.

[0011] Preferably, the bottom of the liquid prism is a triangular bottom plate that can be connected to the adapter slot, and the upper part is a right-angled triangular prism composed of three pieces of glass, and one side is coated with a 55nm silver film.

[0012] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0013] In this application, the liquid prism has the advantages of being able to hold solutions that can be repeatedly filled and easily cleaned, laying the foundation for measuring solutions of various concentrations. The measurement accuracy is determined by the angle displacement platform. By selecting a 0.92 graduation platform, the measurement accuracy can reach 0.3%. The type of solution to be measured only needs to satisfy the requirement that the solution concentration is known and has a linear relationship with the refractive index. The operation is simple, the response time is short, and it is convenient and quick to import and modify data. After automatic processing, clear and intuitive fitting curves, experimental correlation coefficients, relative errors and other parameters can be obtained, data evaluation and data visualization can be completed, and the measurement accuracy of solution concentration can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A schematic diagram of the three-dimensional structure of a self-made solution concentration measuring device based on the SPR angle modulation method provided in an embodiment of the present invention is shown;

[0015] Figure 2 The invention shows a self-made solution concentration measuring device based on the SPR angle modulation method provided by an embodiment of the present invention. Figure 1 A schematic diagram of the enlarged structure of the middle part A;

[0016] Figure 3 The overall optical path schematic diagram of a self-made solution concentration measurement device based on the SPR angle modulation method provided in an embodiment of the present invention is shown;

[0017] Figure 4 A single concentration calibration experiment fitting curve diagram of a homemade solution concentration measurement device based on the SPR angle modulation method provided according to an embodiment of the present invention is shown.

[0018] Legend:

[0019] 1. Operating table; 2. Lifting frame; 3. Lifting platform; 4. Threaded rod; 5. Driving motor; 6. Limit rod; 7. Adapter slot; 8. Liquid prism; 9. Beam splitter base; 10. Polarization beam splitter; 11. Probe base; 12. Laser probe; 13. Wave plate base; 14. 1 / 4 wave plate body; 15. Analyzer base; 16. Linear polarizer; 17. Laser base; 18. Helium-neon laser; 19. Laser power meter; 20. Adapter plate; 21. Angle displacement platform. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] See also Figure 1-4 , the present invention provides a technical solution:

[0022] A self-made solution concentration measuring device based on an SPR angle modulation method comprises an operating table 1, wherein a liftable optical platform mechanism is arranged on the operating table 1, a transfer plate 20 is arranged on the liftable optical platform mechanism, an angle displacement platform 21 is arranged on the transfer plate 20, an embedded transparent transfer groove 7 is arranged on the angle displacement platform 21, a liquid prism 8 is arranged on the transfer groove 7 for holding a solution of unknown concentration, a beam splitter base 9 is arranged on one side of the liftable optical platform mechanism, a polarization beam splitter 10 is arranged on the top of the beam splitter base 9, and the polarization beam splitter 10 can split circularly polarized light into P light and S light, a wave plate base 13 is arranged on one side of the beam splitter base 9, and a 1 / 4 wave plate body is arranged on the top of the wave plate base 13 14. An angle-adjustable 1 / 4 wave plate can be used to convert linearly polarized light into circularly polarized light. An analyzer base 15 is provided on one side of the wave plate base 13. A linear polarizer 16 is provided on the top of the analyzer base 15 to detect the polarization angle of the laser emission. A laser base 17 is provided on one side of the analyzer base 15. A helium-neon laser 18 is provided on the top of the laser base 17. The helium-neon laser 18 generates pure P light to be injected into the liquid prism 8 to generate the SPR phenomenon. A probe base 11 is also provided on one side of the liftable optical platform mechanism. A laser probe 12 is provided on the top of the probe base 11. A laser power meter 19 connected to the laser probe 12 is also provided on one side of the operating table 1 to record the power of the detected laser.

[0023] Specifically, Figure 1As shown, the liftable optical platform mechanism includes a lifting frame 2 and a lifting platform 3. One end of the lifting platform 3 is located inside the lifting frame 2. The lifting frame 2 is also provided with a threaded rod 4 and a limit rod 6 that penetrate the lifting platform 3. The top of the lifting platform 3 is also provided with a driving motor 5 connected to the threaded rod 4. When the driving motor 5 is started, the driving motor 5 drives the threaded rod 4 to rotate. Under the restriction of the limit rod 6, the threaded rod 4 drives the lifting platform 3 to move up and down, thereby adjusting its height.

[0024] Specifically, Figure 1 As shown, the measurement range of the laser power meter 19 is 300-900nm.

[0025] Specifically, Figure 1 As shown, the HeNe laser 18 is a linearly polarized laser that generates a wavelength of 635 nm.

[0026] Specifically, Figure 1 As shown, the accuracy of the angular displacement platform 21 is 0.92 divisions, and there are two adjustment methods: one is coarse adjustment, loosen the coarse adjustment knob, fix the fine adjustment knob, and gently turn the handle of the rotating table to coarsely adjust the rotating platform; the other is fine adjustment, fix the coarse adjustment knob, loosen the fine adjustment knob, and rotate the micrometer. Each scale of the micrometer corresponds to 0.92 divisions to achieve the purpose of fine adjustment.

[0027] Specifically, Figure 2 As shown, the bottom of the liquid prism 8 is a triangular bottom plate that can be connected to the adapter slot 7, and the upper part is a right-angled triangular prism composed of three pieces of glass, and one side is coated with a 55nm silver film. When the film thickness is 55nm, the minimum reflectivity is the smallest, and it has higher sensitivity.

[0028] At the beginning of the experiment, it is necessary to calibrate the relationship curve between the relative incident angle of P light when SPR is generated and the alcohol solution of different concentrations.

[0029] The specific calibration experimental steps are as follows:

[0030] 1) Use gradient dilution method to prepare different low-concentration alcohol solutions (this experiment prepares nine different concentrations of alcohol solutions: 1%, 2%, 3%, 4%, 5%, 7%, 9%, 14%, and 18%);

[0031] 2) Use a rubber-tipped dropper to drip the alcohol solution into the liquid prism 8 until the solution is close to the top;

[0032] 3) Turn on the He-Ne laser 18 light source, the laser beam will be incident on the liquid prism 8, and the beam will be emitted after refraction and reflection, and the laser probe 12 is placed at the beam emission position;

[0033] 4) When the angle starts to change, the angle can be rotated in steps of 5 divisions to observe the reading of the laser power meter 19. When the reading of the laser power meter 19 changes dramatically, the step size is changed to 2 divisions.

[0034] 5) Perform a small range angle change near the relative resonance angle, with a step length of 2 division values, record the reading of the angle displacement platform 21 after each step length change, and the real-time power of the laser power meter 19, and process the recorded data using a computer to produce the following: Figure 4 The scatter plot shown, Figure 4 The rotation angle θmin corresponding to the minimum point of real-time power can be considered as the relative resonance angle corresponding to the alcohol solution of this concentration;

[0035] 6) Record the concentration, refractive index, rotation angle and real-time power corresponding to the above points;

[0036] 7) Replace the alcohol solution with another concentration and repeat steps 2-6.

[0037] By performing Matlab fitting on the recorded data, we can get the following Figure 4 As shown in the fitting curve, it can be seen from the fitting curve that the relative incident angle when the 4% concentration alcohol solution produces SPR is (6°+98×0.92′) and the minimum power value is 0.04283mW.

[0038] Using the above calibration results, we obtained the relationship curve between solution concentration and relative resonance angle. In the formal experiment, we will use this to obtain the concentration of the unknown solution.

[0039] The specific experimental steps are as follows:

[0040] 1. Follow the steps for device construction and experimental preparation.

[0041] 2. Use a rubber-tipped dropper to drop the solution of unknown concentration into the liquid prism 8 until it is close to the top;

[0042] 3. Turn on the He-Ne laser 18 light source, the laser beam will be incident on the liquid prism 8, and the beam will be emitted after refraction and reflection, and the laser probe 12 is placed at the beam emission position;

[0043] 4. When the angle just starts to change, you can rotate it in 5-division steps for coarse adjustment and observe the reading of the laser power meter 19. When the reading of the laser power meter 19 changes dramatically, change the step size to 2 divisions;

[0044] 5. Perform fine adjustment by changing the angle in a small range near the relative resonance angle, and record the reading θ of the angle displacement platform 21 and the real-time power of the laser power meter 19 after each step change;

[0045] 6. The rotation angle θmin corresponding to the minimum point of real-time power in the data scatter plot can be considered as the relative resonance angle corresponding to the alcohol solution of this concentration;

[0046] 7. Substitute the relative resonance angle into the relationship curve between concentration and relative resonance angle obtained from the calibration experiment to obtain the corresponding concentration.

[0047] In summary, the homemade solution concentration measuring device based on the SPR angle modulation method provided in this embodiment has been theoretically calculated to show that the resonance angle does not change when the membrane structure remains unchanged. At the same time, the different refractive indices of solutions of different concentrations will cause the incident angle to change. Therefore, different incident angles correspond to different solution concentrations. The incident angle data is obtained by observing through the angle displacement platform 21, and the relationship between different solution concentrations and the incident angle is analyzed to perform accurate solution concentration measurement, thereby improving the accuracy of solution concentration measurement.

[0048] The above description of the embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A self-made solution concentration measuring device based on the SPR angle modulation method, comprising an operating table (1), characterized in that: The operating table (1) is provided with a liftable optical platform mechanism, the liftable optical platform mechanism is provided with an adapter plate (20), an angle displacement platform (21) is provided on the adapter plate (20), an embedded transparent adapter groove (7) is provided on the angle displacement platform (21), a liquid prism (8) is provided on the adapter groove (7), a beam splitter base (9) is provided on one side of the liftable optical platform mechanism, a polarization beam splitter (10) is provided on the top of the beam splitter base (9), a wave plate base (13) is provided on one side of the beam splitter base (9), and the top of the wave plate base (13) is provided with a polarization beam splitter (10). A quarter wave plate body (14) is arranged at one end of the wave plate base (13); an analyzer base (15) is arranged on one side of the wave plate base (13); a linear polarizer (16) is arranged on the top of the analyzer base (15); a laser base (17) is arranged on one side of the analyzer base (15); a helium-neon laser (18) is arranged on the top of the laser base (17); a probe base (11) is also arranged on one side of the liftable optical platform mechanism; a laser probe (12) is arranged on the top of the probe base (11); and a laser power meter (19) connected to the laser probe (12) is also arranged on one side of the operating table (1); The bottom of the liquid prism (8) is a triangular bottom plate that can be connected to the adapter groove (7), and the upper part is a right-angled triangular prism composed of three pieces of glass, and one side is coated with a 55nm silver film.

2. The self-made solution concentration measuring device based on the SPR angle modulation method according to claim 1, characterized in that: The liftable optical platform mechanism comprises a lift frame (2) and a lift platform (3); one end of the lift platform (3) is located inside the lift frame (2); a threaded rod (4) and a limit rod (6) penetrating the lift platform (3) are also provided inside the lift frame (2); and a driving motor (5) connected to the threaded rod (4) is also provided at the top end of the lift platform (3).

3. The self-made solution concentration measuring device based on the SPR angle modulation method according to claim 1, characterized in that: The measurement range of the laser power meter (19) is 300-900 nm.

4. The self-made solution concentration measuring device based on the SPR angle modulation method according to claim 1, characterized in that: The helium-neon laser (18) is a linearly polarized laser that generates a wavelength of 635 nm.

5. The self-made solution concentration measuring device based on the SPR angle modulation method according to claim 1, characterized in that: The accuracy of the angular displacement platform (21) is 0.92 degrees.

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