CN112147104A - Method for measuring liquid refractive index based on CCD method - Google Patents
Method for measuring liquid refractive index based on CCD method Download PDFInfo
- Publication number
- CN112147104A CN112147104A CN202011272081.2A CN202011272081A CN112147104A CN 112147104 A CN112147104 A CN 112147104A CN 202011272081 A CN202011272081 A CN 202011272081A CN 112147104 A CN112147104 A CN 112147104A
- Authority
- CN
- China
- Prior art keywords
- refractive index
- measuring
- laser
- liquid
- sample
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/41—Refractivity; Phase-affecting properties, e.g. optical path length
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2201/00—Features of devices classified in G01N21/00
- G01N2201/06—Illumination; Optics
- G01N2201/061—Sources
- G01N2201/06113—Coherent sources; lasers
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
The invention relates to an optical precision measurement device, in particular to a method for measuring the refractive index of liquid based on a CCD method. A beam of laser is shot into a measuring container containing a sample to be measured from the diameter direction, enters the sample to be measured after being refracted to form a light path, is converged at one point of an interface by the laser refracted by the interface, is refracted out, is finally arranged on an optical screen, measures the length of the laser on the optical screen, and calculates the refractive index of the liquid. The invention can rapidly measure the liquid refractive index in any environment; the invention is also suitable for measuring the refractive index of solid, thin film and gas; the method has high measurement precision, wherein the precision of measuring the refractive index of the liquid is 0.0001-0.0010 higher; the measuring device is simple, and the operation and the measuring process are convenient; the measuring device of the invention has low price and high cost performance.
Description
Technical Field
The invention relates to an optical precision measurement device, in particular to a method for measuring the refractive index of liquid based on a CCD method.
Background
The refractive index of the liquid is usually measured by an Abbe refractometer, a reading microscope and the like together with an instrument. Although the Abbe refractometer has high measurement accuracy, contact measurement is non-online measurement, which brings inconvenience to production inspection and control, and although a reading microscope can be used for non-contact measurement, the accuracy is not good and has certain limitation. Particularly, when the concentration accuracy requirement in the pharmaceutical industry is high, the ideal requirement is often not met.
The methods for measuring the refractive index of liquid are various, and the laser irradiation method, the optical fiber Young's interference method, the grazing incidence method, the capillary imaging method, the diffraction grating method and the CCD measuring method are mainly introduced below.
Laser irradiation method: the laser irradiation method requires refraction of the liquid and reflection of the surface layer of the liquid when measuring the refractive index. The liquid refractive index is quantitatively tested by using the geometrical relation of light propagation. The refractive index of the liquid is measured using a probability beam at a critical angle. The laser irradiation method has the advantages of simple equipment, low cost and high measurement accuracy, but inaccurate measurement of the spot spacing can reduce the accuracy of the refractive index.
Fiber Young's interference method: the optical fiber Young's interference method uses the optical fiber with small core diameter, uniform light spot and good light transmission as an interference light source, so that the interference pattern is brighter and the fringe is wider, thereby facilitating the measurement. In addition, the method only needs to measure the width of the stripe, and measurement errors are reduced. Although the optical fiber Young's interferometry has high measurement accuracy, the requirement on operation is high, and the optical fiber Young's interferometry is not suitable for wide application.
The grazing surface incidence method is to use Abbe refractometer to measure the refractive index of liquid, and when in use, the refractive index of the liquid to be measured can be directly read from the dial plate only by aligning the cross filament of the telescope with the light and dark boundary line. The grazing incidence method is simple to operate and high in accuracy, but the measuring range of the grazing incidence method is limited.
Capillary imaging method: the capillary filled with transparent liquid is used for forming a cylindrical lens, and based on the imaging principle of a coaxial spherical optical system, the single parameter measurement is carried out on the magnification of the optical imaging system, so that the refractive index of the liquid to be measured is calculated. The capillary tube imaging method is suitable for accurate and rapid measurement of the refractive index of the trace liquid.
Diffraction grating method: the diffraction grating method is a method of measuring the refractive index of a liquid using a cubic glass sample cell, a diffraction grating, and a laser. A transmission grating is placed adjacent to the glass cell and the laser beam is directed perpendicularly onto the grating. When the glass pool is not filled with liquid (only air exists in the pool), the zero-order diffraction light beam is irradiated on a point A on the back wall of the glass pool, the first-order diffraction light beam is irradiated on a point C, and the points are marked on coordinate paper attached outside the pool. After liquid to be measured is injected into the glass pool, the first-order diffraction light beam is refracted when entering the liquid to be measured from air, and then hits a point B on the back wall of the glass pool, and the point is marked on coordinate paper.
CCD measurement: the refractive index of the liquid is calculated by CCD measurement using the relationship between the refractive index of the liquid and the amount of deviation. The refractive index of the liquid is obtained through data measurement and calculation, the CCD can measure the numerical value very accurately, and slight change can be observed, so that certain experimental precision is achieved.
Therefore, a refractive index measuring method with simple and convenient operation and high measuring precision is urgently needed.
Disclosure of Invention
The invention aims to overcome the defects in the prior art and provide a method for measuring the refractive index of liquid.
Another object of the present invention is to provide an application of the above method for measuring refractive index of liquid.
A method for measuring the refractive index of liquid based on a CCD method comprises the following steps:
a method for measuring the liquid refractive index based on a CCD method comprises an electron microscope, a laser emitter, a bracket, a scale and a measuring container, and is characterized in that:
a beam of laser is injected into a measuring container containing a sample to be measured from the diameter direction, enters the sample to be measured to form a light path after being refracted, is converged at one point of an interface by the refraction of the laser of the interface, is finally arranged on an optical screen, and measures the length of the laser on the optical screen;
respectively measuring the lengths of the laser emitted by the sample to be measured on the light screen in the step (1) in an electron microscope, and substituting the lengths into a formula A to calculate the refractive index of the sample to be measured;
obtaining the refractive index of a sample body to be detected in monochromatic light through the steps (1) and (2);
the formula A is as follows:
wherein nx is the refractive index of the sample to be measured, r is the radius of the measuring container, d is the radius width of the laser, and L1 and L2 are the distance from the measuring container to the light screen and the length of the laser on the light screen respectively.
The measuring container in the step (1) is a perfect circle.
The laser emitter emits laser light with wavelength of 655nm and radius of 3 mm.
The electron microscope model is DY-10A, and the resolution is 1980 x 1080.
The polyethylene container with the refractive index of the measurement container in the step (1) being n = 1.0000.
The sample in the step (1) is liquid, solid or film; in the step (2), the sample to be detected is liquid, solid or film; and (3) the length on the light screen in the step (2) is clear, and the visible boundary is clear.
The method is applied to measuring the refractive index of a sample.
Compared with the prior art, the invention has the advantages and effects that: the invention can rapidly measure the liquid refractive index in any environment; the invention is also suitable for measuring the refractive index of solid, thin film and gas; the method has high measurement precision, wherein the precision of measuring the refractive index of the liquid is 0.0001-0.0010 higher; the measuring device is simple, and the operation and the measuring process are convenient; the measuring device of the invention has low price and high cost performance.
Drawings
FIG. 1 is a flow chart of a measurement method of the present invention;
FIG. 2 is a schematic optical path diagram of the measurement principle of the present invention;
FIG. 3 is a schematic view of a measuring apparatus and a light path diagram provided in embodiment 1 of the present invention;
FIG. 4 is a schematic view of a measuring apparatus and a light path provided in embodiment 2 of the present invention;
FIG. 5 is a graph showing the refractive index profile of an olive oil solution in example 1 of the present invention;
FIG. 6 is a graph showing the refractive index profile of the aqueous tap solution in example 2 of the present invention.
Detailed Description
The flow of measuring the refractive index of the liquid is shown in fig. 1, and specifically comprises the following steps: a beam of laser is shot into a measuring container containing a sample to be measured from the diameter direction, enters the sample to be measured after being refracted to form a light path, is converged at one point of an interface through interface refraction laser, is refracted out, is finally arranged on an optical screen, measures the length of the laser on the optical screen, and calculates the refractive index of the sample to be measured according to a formula A.
The principle analysis of the method of the invention is as follows:
the experimental device designed by the two-dimensional vertical refractometry method has the advantage that the thickness is approximately zero because the culture dish container is a circle. The laser beam is incident from the radial direction, the width of the laser beam is d, and the incident point is A, B. The included angle between the normal line and the diameter is 2r, the laser is refracted after entering the liquid and is intersected with the point C, the laser is refracted again at the point C and enters the air, the refraction angle is i, the vertical distance from the second refraction to the point C is L1, and the width of the two refracted lasers is L2. As shown in fig. 2. The distance d can be known from laser parameters, L1 is the distance from the measuring container to the light screen, and L2 can be accurately measured by a CCD.
The radius of the culture dish is r, and the radius width of the laser is d; the refractive index of air is approximately 1 and the refractive index of liquid is nx.
From the refractive index formula of light:
the light path adjusting process of the device is as follows: laser is injected along the diameter of the measuring container, is refracted and then is injected out of a sample to be measured to form a line on the light screen, and the light intensity is adjusted to form a clear visible line.
The specific measurement steps of the device are as follows: (1) adjusting the CCD: firstly, a power supply is turned on, a USB of the CCD is connected with a computer, computer shooting software S-EYE is turned on, a camera is selected from camera options, resolution 1980 x 1080 is selected from preview, the CCD is adjusted to be in a proper height, an eyepiece is adjusted, and focusing is carried out according to pictures so as to achieve the highest definition.
(2) Calibration: selecting measurement in S-EYE software, clicking in a calibration column to edit and input a required name, putting an object (ruler, standard … …) with a known size into the CCD dosage range to make the object in the center of the picture, dragging the ruler in the software to calibrate, and completing calibration and clicking for addition.
(3) Measuring the refractive index of the liquid to be measured: the liquid to be measured is placed in a visual field, laser incidence is adjusted, a clear visible light path appears in the center of the CCD, the distances from the measuring container to the light screen are respectively measured by L1, L2 and L1, and the distance d is the diameter of the laser and only needs to be measured by L2. Wherein L2 measures the distance from the calibrated S-EYE. At this time, L1 and L2 were recorded.
(4) And calculating the refractive index of the sample to be measured, and measuring the obtained L1 and L2. And substituting the formula A to obtain the refractive index of the sample to be measured, repeating the steps for multiple times, repeating the experiments for 3-5 times, obtaining data, and calculating to obtain the refractive index nx.
The present invention will be described in further detail with reference to examples and drawings, but the embodiments of the present invention are not limited thereto.
Example 1
A device for measuring the liquid refractive index based on a CCD method is shown in figure 3 and comprises a laser emitter 1, a measuring container 2, an electron microscope 3, a support, a scale and a light screen 4.
The light path adjusting process of the device is as follows: laser is injected along the diameter of the measuring container, enters a sample to be measured to form a light path after being refracted, is converged at one point of an interface and is emitted out on a light screen to form a straight line, and the light intensity is adjusted to form a clear and visible straight line.
The specific measurement steps of the device are as follows:
(1) adjusting the CCD: firstly, a power supply is turned on, a USB of the CCD is connected with a computer, computer shooting software S-EYE is turned on, a camera is selected from camera options, resolution 1980 x 1080 is selected from preview, the CCD is adjusted to be in a proper height, an eyepiece is adjusted, and focusing is carried out according to pictures so as to achieve the highest definition.
(2) Calibration: selecting measurement in S-EYE software, clicking in a calibration column to edit and input a required name, putting an object (ruler, standard … …) with a known size into the CCD dosage range to make the object in the center of the picture, dragging the ruler in the software to calibrate, and completing calibration and clicking for addition.
Measurement of refractive index of olive oil: the liquid to be measured is placed on a support, laser incidence is adjusted, a straight line appears in the center of the CCD, the distances from a measuring container to a light screen are measured respectively through L1, L2 and L1, and only L2 needs to be measured when the diameter d is known as the diameter of the laser. Wherein L2 measures the distance from the calibrated S-EYE.
(3) At this time, L1 and L2 were recorded.
(4) And calculating the refractive index of the sample to be measured, substituting the measured L1 and L2 into a formula A to obtain the refractive index of the olive oil, measuring for multiple times, repeating the steps, repeating the 3-5 experiments to obtain data, and calculating to obtain the refractive index nx.
The refractive index of olive oil measured by Abbe refractometer is taken as a standard, and the result is shown in FIG. 5: the surface of the measuring device and the measuring method provided by the embodiment are very close to the detection result of a common Abbe refractometer, and the relative error is within 0.1 percent.
Example 2
The device provided by the embodiment is different from the device provided by the embodiment 1 in that: the liquid sample was different, i.e. olive oil was changed to tap water.
And calculating the refractive index of the sample to be measured, substituting the measured L1 and L2 into a formula A to obtain the refractive index of the olive oil, measuring for multiple times, repeating the steps, repeating the 3-5 experiments to obtain data, and calculating to obtain the refractive index nx.
The refractive index of corn oil measured by Abbe refractometer is taken as a standard by using the device and method provided in this example, and the results are shown in FIG. 6: the surface of the measuring device and the measuring method provided by the embodiment are very close to the detection result of a common Abbe refractometer, and the relative error is also within 0.1 percent.
In short, the specific structure of the present invention is various, and any device that uses a beam of monochromatic light to inject into a perfect circle measuring container and measures the refractive index of the sample to be measured by detecting the parameters of the light path in the solution belongs to the protection scope of the present application.
The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention and are equivalent to the replacement of the above embodiments are included in the scope of the present invention.
Claims (7)
1. A method for measuring the liquid refractive index based on a CCD method comprises an electron microscope, a laser emitter, a bracket, a scale and a measuring container, and is characterized in that:
(1) a beam of laser is injected into a measuring container containing a sample to be measured from the diameter direction, enters the sample to be measured to form a light path after being refracted, is converged at one point of an interface by the refraction of the laser of the interface, is finally arranged on an optical screen, and measures the length of the laser on the optical screen;
(2) respectively measuring the lengths of the laser emitted by the sample to be measured on the light screen in the step (1) in an electron microscope, and substituting the lengths into a formula A to calculate the refractive index of the sample to be measured;
(3) obtaining the refractive index of a sample body to be detected in monochromatic light through the steps (1) and (2);
the formula A is as follows:
wherein nx is the refractive index of the sample to be measured, r is the radius of the measuring container, d is the radius width of the laser, and L1 and L2 are the distance from the measuring container to the light screen and the length of the laser on the light screen respectively.
2. The method for measuring the refractive index of the liquid based on the CCD method according to claim 1, wherein: the measuring container in the step (1) is a perfect circle.
3. The method for measuring the refractive index of the liquid based on the CCD method according to claim 1, wherein: the laser emitter emits laser wavelength of 655nm and radius of 3 mm.
4. The method for measuring the refractive index of the liquid based on the CCD method according to claim 1, wherein: the model of the electron microscope is DY-10A, and the resolution is 1980 x 1080.
5. The method for measuring the refractive index of the liquid based on the CCD method according to claim 1, wherein: the polyethylene container with the refractive index of the measurement container in the step (1) being n = 1.0000.
6. The method for measuring the refractive index of the liquid based on the CCD method according to claim 1, wherein:
the sample in the step (1) is liquid, solid or film;
in the step (2), the sample to be detected is liquid, solid or film;
and (3) the length on the light screen in the step (2) is clear, and the visible boundary is clear.
7. The method for measuring the liquid refractive index based on the CCD method of any one of claims 1 to 6, which is applied to the measurement of the sample refractive index.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011272081.2A CN112147104A (en) | 2020-11-14 | 2020-11-14 | Method for measuring liquid refractive index based on CCD method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011272081.2A CN112147104A (en) | 2020-11-14 | 2020-11-14 | Method for measuring liquid refractive index based on CCD method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112147104A true CN112147104A (en) | 2020-12-29 |
Family
ID=73887377
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011272081.2A Withdrawn CN112147104A (en) | 2020-11-14 | 2020-11-14 | Method for measuring liquid refractive index based on CCD method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112147104A (en) |
-
2020
- 2020-11-14 CN CN202011272081.2A patent/CN112147104A/en not_active Withdrawn
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPH1183438A (en) | Position calibration method for optical measuring device | |
| CN107121095A (en) | A kind of method and device of accurate measurement super-large curvature radius | |
| KR101169586B1 (en) | Apparatus for measuring thickness change, system using the apparatus, morphology microscope using the apparatus, method for measuring thickness change, and method for acquiring morphology image using the method | |
| CN111458108A (en) | Device and method for measuring parallelism of transmitting and receiving optical axes | |
| JP2010223915A (en) | Method and device for measuring positional variation of center line of rotation | |
| CN110736721B (en) | Glass plate refractive index uniformity detection device and detection method based on diffraction grating | |
| CN106932179A (en) | The method and device that off-axis paraboloidal mirror is measured off axis is demarcated based on grating scale and theodolite | |
| CN117006958A (en) | Precise measurement method for geometric characteristics of inner surface of small hole with high depth-diameter ratio | |
| US10260988B2 (en) | Non-contact measurement device for radius of curvature and thickness of lens and measurement method thereof | |
| CN112285059A (en) | Device for measuring liquid refractive index based on CCD method | |
| CN101701912A (en) | Method for nondestructive measurement of refractive index of transparent capillary wall and device thereof | |
| CN110207587B (en) | Method for measuring optical vertex of pyramid prism | |
| CN112147104A (en) | Method for measuring liquid refractive index based on CCD method | |
| CN116381708A (en) | High-precision laser triangular ranging system | |
| TWI545315B (en) | Method for producing a mirror substrate blank of titanium-doped silica glass for euv lithography, and system for determining the position of defects in a blank | |
| CN216284233U (en) | Off-axis aspherical mirror detection device and detection system | |
| CN112198139A (en) | Liquid refractive index measuring device based on line laser | |
| CN105180820B (en) | A kind of transparent capillary inner surface face type test system and method for testing | |
| CN217332162U (en) | Device for measuring liquid refractive index by using linear array CCD | |
| JP2830943B2 (en) | Optical shape measurement method | |
| JPS63255608A (en) | Method for calibrating dripping liquid droplet detector | |
| CN214201178U (en) | Liquid refractive index measuring device based on line laser | |
| CN212228353U (en) | Optical quality detection device of four-quadrant detector lens | |
| CN219224566U (en) | Transparent solution concentration measuring device | |
| Ma et al. | Measuring film thickness with Dual-laser imaging method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WW01 | Invention patent application withdrawn after publication | ||
| WW01 | Invention patent application withdrawn after publication |
Application publication date: 20201229 |