CN112345493A - Liquid refractive index measuring method - Google Patents
Liquid refractive index measuring method Download PDFInfo
- Publication number
- CN112345493A CN112345493A CN202011125638.XA CN202011125638A CN112345493A CN 112345493 A CN112345493 A CN 112345493A CN 202011125638 A CN202011125638 A CN 202011125638A CN 112345493 A CN112345493 A CN 112345493A
- Authority
- CN
- China
- Prior art keywords
- temperature
- measuring
- constant
- jacket
- observation window
- 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.)
- Pending
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
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)
- Optical Measuring Cells (AREA)
Abstract
The invention provides a method for measuring the refractive index of liquid, which comprises the following steps: setting a measuring tank, wherein the measuring tank is a hollow triangular prism, and injecting a liquid sample to be measured into the measuring tank at a set height; arranging a constant-temperature jacket, wherein the constant-temperature jacket is a hollow triangular prism, the measuring pool is nested in the constant-temperature jacket, a hollow pipeline is arranged in the constant-temperature jacket, the hollow pipeline is connected with a circulating water bath, and the temperature of the measuring pool is controlled to be constant through the circulation of water in the circulating water bath in the hollow pipeline; observation windows are arranged on at least two side surfaces of the constant-temperature jacket, so that light rays irradiate the liquid sample to be measured in the measuring cell through one observation window and are refracted out from the other observation window; and obtaining the refractive index of the liquid sample to be detected by an angle measurement method according to the incident angle and the emergent angle of the light rays in the observation window. The method accurately measures the refractive index of the liquid.
Description
Technical Field
The invention relates to the technical field of refractive index measurement, in particular to a method for measuring a liquid refractive index.
Background
The refractive index is one of the most basic physical and chemical properties of substances, and is an important technical index for measuring the quality of various social commodities and industrial materials. The measurement of the refractive index is not obvious in the fields of automobile manufacturing, optical materials, petrochemical industry, food industry, pharmaceutical industry and the like. Particularly for the beverage and wine industry in the food industry, the liquid refractive index is applied to the determination of the contents of sugar, alcohol and other food additives and is a key parameter for quality assurance, and the accuracy of the measurement result directly determines whether the product quality meets the national food safety standard.
Refractive index measurement methods are many, and the most reliable and accurate method is a precise angle measurement method based on the principle of minimum deviation angle. The refractive index of the sample to be measured can be calculated by precisely measuring the vertex angle of the sample to be measured processed into the triangular prism and the minimum deviation angle between the incident angle and the emergent angle through a precise angle measuring instrument, and the measurement accuracy can reach 10 at most-6Magnitude. Since the refractive index measurement by the method requires that the sample to be measured must be processed into a triangular prism with an accurately known vertex angle, the method is generally limited to the measurement of the refractive index of solid materials.
Disclosure of Invention
In view of the above problems, the present invention provides a liquid refractive index measuring method that accurately measures the refractive index of a liquid.
In order to achieve the above object, the present invention provides a method for measuring a refractive index of a liquid, comprising:
setting a measuring tank, wherein the measuring tank is a hollow triangular prism, and injecting a liquid sample to be measured into the measuring tank at a set height;
arranging a constant-temperature jacket, wherein the constant-temperature jacket is a hollow triangular prism, the measuring pool is nested in the constant-temperature jacket, a hollow pipeline is arranged in the constant-temperature jacket, the hollow pipeline is connected with a circulating water bath, and the temperature of the measuring pool is controlled to be constant through the circulation of water in the circulating water bath in the hollow pipeline;
observation windows are arranged on at least two side surfaces of the constant-temperature jacket, so that light rays irradiate the liquid sample to be measured in the measuring cell through one observation window and are refracted out from the other observation window;
and obtaining the refractive index of the liquid sample to be detected by an angle measurement method according to the incident angle and the emergent angle of the light rays in the observation window.
Preferably, the step of obtaining the refractive index of the liquid sample to be measured by an angle measurement method according to the incident angle and the emergent angle of the light in the observation window comprises:
obtaining a minimum deviation angle according to the incident angle of the light ray in one observation window and the emergent angle of the light ray in the other observation window;
obtaining the refractive index of the liquid sample to be detected according to the following formula through the minimum deviation angle
Wherein n is the refractive index of the sample to be detected; a is a vertex angle of the measuring pool, and the vertex angle of the measuring pool is an angle of the measuring pool corresponding to an included angle of the side surface of the constant-temperature jacket provided with the observation window; deltamIs the minimum deviation angle.
Further, preferably, the vertex angle of the measuring cell ranges from 45 degrees to 65 degrees.
Preferably, the step of controlling the temperature of the temperature measuring cell to be constant by circulating water in the circulating water bath in the hollow pipeline comprises:
measuring the temperature of the temperature measuring pool through a temperature sensor;
and setting the target temperature of the circulating water bath, and controlling the temperature fluctuation of the temperature measuring pool to be smaller than a set value through the circulating water bath.
Preferably, the step of providing a hollow pipe inside the thermostatic jacket comprises:
the hollow pipeline of the constant-temperature jacket is arranged in a counter-flow manner;
the distance between the hollow pipeline and the outer wall and the inner wall of the constant-temperature jacket is equal, the hollow pipeline on the side surface of the constant-temperature jacket provided with the observation window is in circuitous symmetrical distribution relative to the axis of the observation window, and the hollow pipelines on the side surface, the bottom surface and the top surface of the constant-temperature jacket not provided with the observation window are in uniform distribution with equal distance.
Preferably, the step of measuring the temperature of the temperature measuring cell by the temperature sensor comprises:
setting the constant-temperature jacket into a detachable form comprising a constant-temperature jacket top cover and a constant-temperature jacket cylinder;
setting the measuring cell into a detachable connection mode comprising a measuring cell top cover and a measuring cell cylinder;
a plurality of through holes are formed in the top cover of the measuring cell and the top cover of the constant-temperature jacket and used for inserting temperature measuring probes of the temperature sensor;
and measuring the temperatures of different areas of the temperature measuring pool by a temperature measuring probe.
Preferably, the measuring cell and the thermostatic jacket are hollow isosceles triangular prisms.
Preferably, the measuring cell is made of fused quartz, the constant-temperature jacket is made of high-thermal-conductivity metal material, and heat-conducting silicone grease is filled between the measuring cell and the constant-temperature jacket.
Preferably, an observation window is symmetrically arranged at the central position of each of the two side walls of the thermostatic jacket, so that the emitted light beam passes through the observation window when the emitted light beam forms a set angle range with the normal of the side surface of the thermostatic jacket.
Preferably, the opening of the observation window is small inside and large outside.
The method for measuring the refractive index of the liquid adopts the accurate temperature measuring pool with the triangular prism structure to contain the liquid, and can meet the basic measurement requirement of a precise angle measuring instrument on the refractive index of the liquid. The temperature is kept constant by the constant-temperature jacket and the circulating water bath, the temperature field difference is negligible, the temperature setting range only depends on the working temperature range of the used external circulating water bath, and the refractive index of the liquid sample is 10-6Precise determination of magnitude accuracy.
Drawings
FIG. 1 is a flow chart of a method of measuring the refractive index of a liquid according to the present invention;
FIG. 2 is a schematic perspective view of the measuring cell and thermostatic jacket according to the present invention;
FIG. 3 is a schematic representation of the goniometry method of the present invention;
FIG. 4a is a schematic view of the arrangement of the hollow pipes on the side of the thermostatic jacket according to the invention without the observation window;
FIG. 4b is a schematic view of the arrangement of the hollow pipes on the side of the thermostatic jacket with the observation window according to the present invention;
FIG. 4c is a schematic view of the arrangement of the hollow pipes of the bottom face of the thermostatic jacket according to the invention;
FIG. 4d is a schematic view of the arrangement of the hollow pipes of the top face of the thermostatic jacket according to the invention;
FIG. 5 is a schematic representation of different liquids measured at different top angles of a cell according to the present invention.
In the drawings, the same reference numerals indicate similar or corresponding features or functions.
Detailed Description
In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments. It may be evident, however, that such embodiment(s) may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate describing one or more embodiments.
Various embodiments according to the present invention will be described in detail below with reference to the accompanying drawings.
Fig. 1 is a flow chart of a liquid refractive index measuring method of the present invention, fig. 2 is a schematic perspective view of a constant temperature refractive index measuring cell of the present invention, and as shown in fig. 1, the liquid refractive index measuring method includes:
step S1, setting a measuring cell 11, wherein the measuring cell is a hollow triangular prism, and injecting a liquid sample to be measured into the measuring cell to set the height;
step S2, arranging a constant temperature jacket 1 which is a hollow triangular prism, nesting the measuring pool in the constant temperature jacket, arranging a hollow pipeline 4 in the constant temperature jacket, connecting the hollow pipeline with a circulating water bath, and controlling the temperature of the measuring pool to be constant through the circulation of water in the circulating water bath in the hollow pipeline;
step S3, arranging observation windows 3 on at least two side surfaces of the constant temperature jacket, so that light rays irradiate the liquid sample to be measured in the measuring cell through one observation window and are refracted out from the other observation window;
and step S4, obtaining the refractive index of the liquid sample to be measured by an angle measurement method according to the incident angle and the emergent angle of the light in the observation window.
In step S2, the step of controlling the temperature of the temperature measuring cell to be constant by circulating the water in the circulating water bath in the hollow pipeline comprises:
measuring the temperature of the temperature measuring pool through a temperature sensor;
and setting the target temperature of the circulating water bath, and controlling the temperature fluctuation of the temperature measuring pool to be smaller than a set value through the circulating water bath.
Preferably, the step of measuring the temperature of the temperature measuring cell by the temperature sensor comprises:
the constant temperature jacket is set to be a detachable form comprising a constant temperature jacket top cover 5 and a constant temperature jacket cylinder;
the measuring cell is arranged into a detachable connection mode comprising a measuring cell top cover 9 and a measuring cell cylinder body;
a plurality of through holes are formed in the top cover of the measuring cell and the top cover of the constant-temperature jacket and used for inserting temperature measuring probes of the temperature sensor;
and measuring the temperatures of different areas of the temperature measuring pool by a temperature measuring probe.
In step S2, the step of providing a hollow pipe inside the thermostatic jacket includes:
the hollow pipeline of the constant-temperature jacket is arranged in a counter-flow manner;
the distance between the hollow pipeline and the outer wall and the inner wall of the constant-temperature jacket is equal, the hollow pipeline on the side surface of the constant-temperature jacket provided with the observation window is in circuitous symmetrical distribution relative to the axis of the observation window, and the hollow pipelines on the side surface, the bottom surface and the top surface of the constant-temperature jacket not provided with the observation window are in uniform distribution with equal distance.
Preferably, the bottom surface of the thermostatic jacket is communicated with the hollow pipelines on each side surface.
Preferably, the hollow pipelines on the bottom surface of the constant-temperature jacket are distributed in a triangular winding manner.
Through the water route design of the hollow pipeline of the constant temperature jacket, the temperature fluctuation of the measured liquid caused by the temperature fluctuation of the circulating water bath is further reduced, the uniformity of the temperature fields of different areas of the liquid is improved, and the measurement precision of the refractive index is higher.
In one embodiment, in step S3, the measuring cell and the thermostatic jacket are hollow isosceles triangular prisms, and an observation window is symmetrically disposed at the center of each of the two side surfaces of the thermostatic jacket so that the emitted light beam passes through the observation window within a predetermined angle range from the normal line of the side surface of the thermostatic jacket.
Preferably, the measuring cell and the thermostatic jacket are hollow right isosceles triangular prisms.
Preferably, the opening of the observation window is small inside and large outside. The size of the opening of the observation window is set according to the diameter (spot size) of the emission beam.
In one embodiment, in step S4, as shown in fig. 3, the step of obtaining the refractive index of the liquid sample to be measured by an angle measurement method according to the incident angle and the exit angle of the light at the observation window includes:
obtaining a minimum deviation angle according to the incident angle of the light ray in one observation window and the emergent angle of the light ray in the other observation window;
obtaining the refractive index of the liquid sample to be detected according to the following formula through the minimum deviation angle
Wherein n is the refractive index of the sample to be detected; a is a vertex angle of the measuring pool, and the vertex angle of the measuring pool is an angle of the measuring pool corresponding to an included angle of the side surface of the constant-temperature jacket provided with the observation window; deltamIs the minimum deviation angle.
As shown in fig. 3, the ray deflection angle δ ═ i1+i3A, when i1＝i2When delta is equal to deltamWherein i is1For the angle of incidence of light in an observation window，i2Angle of refraction, i, of light in an observation window3The angle of incidence of light in another viewing window, i4Is the exit angle of the light ray in the other observation window.
Preferably, the vertex angle of the measuring cell ranges from 45 degrees to 65 degrees.
In one embodiment, the measuring cell is made of fused quartz, the constant-temperature jacket is made of high-thermal-conductivity metal material, and heat-conducting silicone grease is filled between the measuring cell and the constant-temperature jacket.
In one embodiment, as shown in fig. 2, the thermostatic jacket 1 is made of a high thermal conductivity metal material, for example, pure copper. The vertex angle of the thermostatic jacket 1 is equal to that of the measuring cell 11, for example, 65 degrees, the angle error is not more than +/-0.1 degrees, and the inner dimension of the thermostatic jacket 1 is slightly larger than the outer contour dimension of the measuring cell 11, so that clearance fit is formed. An observation window is symmetrically arranged at the central position of each of two side walls of the constant temperature jacket so as to allow a transmitted light beam to pass through when the transmitted light beam forms a set angle range with the normal of the side surface of the constant temperature jacket, preferably, the central position of two side walls (two side surfaces) of two waist of the constant temperature jacket 1 is symmetrically provided with an observation window 3 and 3 'with small opening inside and large outside respectively, in order to ensure that the light beam emitted by a precision goniometer light source can completely irradiate the measuring cell 11, the minimum opening size of the observation window 3 and 3' is not less than 15mm multiplied by 15mm, in order to ensure the constant temperature effect, the maximum opening area of the observation window is not more than 2/3 of the area of the side wall, circular, elliptical, rectangular and other opening forms can be adopted, preferably, the opening inside and outside of the observation window is large, for example, a terrace opening form forming an angle of 45 degrees from the outside to the inside can be adopted, when the, it is still ensured that the light is not blocked. And the central positions of two side walls of the constant temperature jacket are respectively symmetrically provided with an observation window so that the emitted light beams pass through the observation windows when forming a set angle range with the normal of the side surface of the constant temperature jacket.
The measuring cell 11 may be made of chemically inert, optically transparent material such as optical glass, fused silica, etc., preferably, the measuring cell is made of fused silica, for example, fused silica having a spectral transmittance of 200nm to 1000nm of more than 80% and no significant characteristic absorption.
In one embodiment, as shown in fig. 4a-4d, the hollow pipes of the thermostatic jacket are arranged in a counter-flow manner, and the hollow pipes are equally spaced from the outer wall and the inner wall of the thermostatic jacket. Preferably, a pagoda-shaped water outlet 2 and a pagoda-shaped water inlet 2' are arranged above one of the side surfaces of the thermostatic jacket 1, and are communicated with a hollow pipeline 4 in the thermostatic jacket.
As shown in fig. 4a, the hollow pipes on the side of the thermostatic jacket not provided with the observation window are uniformly distributed at equal intervals.
As shown in fig. 4b, the hollow pipes of the side of the thermostatic jacket provided with the observation window are arranged in a winding symmetrical distribution, preferably in a zigzag winding symmetrical distribution, with respect to the axis of the observation window, extending up to the bottom and the other sides, until the pipes are evenly distributed in each wall of the thermostatic jacket 1.
As shown in fig. 4c, the hollow pipes on the bottom surface of the thermostatic jacket are uniformly distributed at equal intervals, preferably, in a triangular winding.
As shown in fig. 4d, a pagoda-shaped water outlet 7 and a pagoda-shaped water inlet 7' are respectively arranged above the constant temperature jacket top cover 5 and are communicated with the hollow pipeline 4 in the jacket top cover 5. As shown in fig. 3c, the hollow pipes 4 are of a counterflow design, are equally spaced from the upper and lower surfaces of the thermostatic jacket top cover 5, and are equally spaced from the inner ring to the outer ring within the thermostatic jacket top cover 5. The water inlet 7' is connected with the inlet of the inner ring of the hollow pipeline 4, and the water outlet 7 is connected with the outlet of the outer ring of the hollow pipeline 4.
The pipeline layout form of the invention can improve the temperature exchange performance and reduce the temperature field difference of each area.
As shown in fig. 2 and 4d, a plurality of first through holes 6 are formed in the top cover of the constant temperature jacket, a plurality of second through holes 10 are formed in the top cover of the measurement cell, and the first through holes and the second through holes are used for inserting temperature probes of the temperature sensor. Preferably, the second through hole diameter is larger than the diameter of the first through hole.
In a preferred embodiment, the thermostatic jacket top cover 5 is made of the same material as the thermostatic jacket 1, for example, pure copper. A circular through hole 6 (a first through hole) is arranged at the central axis close to one end of the top corner, and another circular through hole 6' (the first through hole) with the same caliber is arranged at one end of the central axis extending to the bottom edge. The first through-holes 6 and 6 'are concentric with the second through-holes 10 and 10' of the measuring cell top cover 9, respectively. The diameters of the through hole 6 and the through hole 6 ' are slightly larger than the diameters of the through hole 10 and the through hole 10 ', so that the temperature measuring probe is prevented from contacting with the inner walls of the through hole 10 and the through hole 10 ' after being inserted, and the heat flow of the top cover 5 of the constant temperature jacket is prevented from being conducted to the temperature measuring probe through contact, so that the real temperature of the measured liquid sample is influenced.
As shown in FIG. 2, the top cover 9 of the measuring cell may be made of the same material as the measuring cell 11, or a material having a thermal expansion coefficient similar to that of the measuring cell 11 and not physically and chemically reacting with the liquid sample to be measured, such as fused silica. A circular through hole 10 (a second through hole) is arranged at the central axis close to one end of the top corner, another circular through hole 10 '(the second through hole) with the same caliber is arranged at one end of the central axis extending to the bottom edge, and the diameters of the second through holes 10 and 10' are suitable for inserting a temperature measuring probe.
In one embodiment, the measuring cell and the thermostatic jacket are hollow isosceles triangular prisms, preferably, the measuring cell and the thermostatic jacket are hollow isosceles triangular prisms. The measuring tank top angle can be processed to be 20-90 degrees, for example 65 degrees, and the angle error is not more than +/-0.1 degrees. The side wall where the base of the isosceles triangle is located is frosted, the thickness of the side wall where the two waists are located is equal, and the thickness can be 3mm to 10mm, for example 5 mm. The parallelism of the inner and outer surfaces of the wall is not more than 10 ', the difference between the towers is not more than 1', the surface roughness is not more than lambda/10, and the surface roughness is not more than 20nm for measuring the refractive index of the liquid in the range of 200nm to 1000 nm.
In a preferred embodiment, the liquid refractive index measurement method of the present invention includes:
the method comprises the steps of filling a liquid sample to be measured into a measuring cell 11 to a set height (preferably, 90% of the height), placing a measuring cell top cover 9 on the measuring cell 11 for sealing, then uniformly coating a thin layer of heat conduction silicone grease or liquid paraffin on the upper surface of the measuring cell top cover 9, and placing a constant temperature jacket top cover 5 above a constant temperature jacket 1 for sealing. Connecting a water inlet 7 'of the jacket top cover 5 with a water outlet of an external constant-temperature circulating water bath (not shown in the figure) by using a heat preservation hose (not shown in the figure) with a proper caliber, connecting the water outlet 7 of the jacket top cover 5 with a water inlet 2' of the constant-temperature jacket 1, and connecting a water outlet 2 of the constant-temperature jacket 1 with a water inlet of the external constant-temperature circulating water bath (not shown in the figure);
and (3) opening a circulating water bath (not shown in the figure), allowing circulating water to enter the hollow pipeline inside the jacket top cover 5 through the water inlet 7' of the jacket top cover 5, and finally flowing out of the water outlet of the constant-temperature jacket 1 to return to the constant-temperature circulating water bath (not shown in the figure), so as to realize the temperature control of the constant-temperature jacket 1 and the jacket top cover 5 on the liquid sample to be measured in the measuring cell 11. The target temperature of the constant-temperature circulating water bath is set by monitoring the actual temperature values fed back by two temperature measuring probes (not shown in the figure) inserted into the liquid sample to be measured in the measuring cell, and the refractive index of the liquid can be measured when the temperature of the sample reaches the expected target and is stable.
In a specific embodiment of the invention, the measuring cell and the constant temperature jacket are hollow right isosceles triangular prisms, the diameter (light spot size) of a light beam emitted by the measuring instrument is 1cm multiplied by 1cm at the minimum, the conventional light spot is 3cm multiplied by 3cm, in order to enable incident light and emergent light to pass through an observation window at a certain angle, the opening size of the observation window is more than 5cm multiplied by 5cm, the periphery of the observation window is obliquely opened outwards, and the temperature coefficient of the refractive index of the normal temperature liquid is generally (3-5) multiplied by 10-4That is, the temperature changes by 1 ℃, the refractive index changes by 0.0003 to 0.0005, and the measurement precision of the refractive index is 1 multiplied by 10-5The temperature fluctuation must be less than 0.2 ℃, and the measurement accuracy of the refractive index is 1 multiplied by 10-6The temperature fluctuation and the temperature field gradient must be less than 0.02 ℃, so high temperature control requirements are met, except that the whole set of test equipment and a sample are measured in a thermostatic chamber (20 +/-0.5 ℃), the temperature of the sample is controlled through a thermostatic jacket, the thermostatic jacket is a heat-conducting metal jacket with mutually staggered internal pipelines and is connected to a thermostatic circulating water bath, the circulating water bath with good temperature control performance (the fluctuation is less than 0.2 ℃ or 0.02 ℃) is selected, and the fluid countercurrent heat exchange is realized by the pipeline with the staggered circulating thermostatic jacket, so that good temperature fluctuation and temperature field gradient are achievedCan be used.
The relation between the refractive index which can be measured by corresponding to different triangular prism vertex angles of the measuring cell and the minimum deviation angle is shown in figure 5, the refractive index of common liquid is 1.3-1.8, and therefore the selectable range of the triangular prism vertex angles is generally 45-65 degrees.
The liquid refractive index measuring method enables liquid to form a triangular prism-like shape and is used for measuring the refractive index of a liquid material, meanwhile, as the refractive index-temperature coefficient of the liquid material is far larger than that of a solid material, the temperature of a liquid sample can be precisely, uniformly and stably controlled, and a precise temperature control triangular prism-shaped measuring pool for a precise angle measuring instrument is provided, so that the refractive index of the liquid can be precisely measured.
While the foregoing disclosure shows illustrative embodiments of the invention, it should be noted that various changes and modifications could be made herein without departing from the scope of the invention as defined by the appended claims. Furthermore, although elements of the invention may be described or claimed in the singular, the plural is contemplated unless limitation to a single element is explicitly stated.
Claims (10)
1. A method of measuring refractive index of a liquid, comprising:
setting a measuring tank, wherein the measuring tank is a hollow triangular prism, and injecting a liquid sample to be measured into the measuring tank at a set height;
arranging a constant-temperature jacket, wherein the constant-temperature jacket is a hollow triangular prism, the measuring pool is nested in the constant-temperature jacket, a hollow pipeline is arranged in the constant-temperature jacket, the hollow pipeline is connected with a circulating water bath, and the temperature of the measuring pool is controlled to be constant through the circulation of water in the circulating water bath in the hollow pipeline;
observation windows are arranged on at least two side surfaces of the constant-temperature jacket, so that light rays irradiate the liquid sample to be measured in the measuring cell through one observation window and are refracted out from the other observation window;
and obtaining the refractive index of the liquid sample to be detected by an angle measurement method according to the incident angle and the emergent angle of the light rays in the observation window.
2. The method for measuring the refractive index of a liquid according to claim 1, wherein the step of obtaining the refractive index of the liquid sample to be measured by an angle measurement method according to the incident angle and the emergent angle of the light at the observation window comprises:
obtaining a minimum deviation angle according to the incident angle of the light ray in one observation window and the emergent angle of the light ray in the other observation window;
obtaining the refractive index of the liquid sample to be detected according to the following formula through the minimum deviation angle
Wherein n is the refractive index of the sample to be detected; a is a vertex angle of the measuring pool, and the vertex angle of the measuring pool is an angle of the measuring pool corresponding to an included angle of the side surface of the constant-temperature jacket provided with the observation window; deltamIs the minimum deviation angle.
3. The method for measuring the refractive index of a liquid according to claim 2, wherein the vertex angle of the measuring cell is in the range of 45 ° to 65 °.
4. The method of claim 1, wherein the step of controlling the temperature of the cuvette to be constant by circulation of water in a circulating water bath in the hollow pipe comprises:
measuring the temperature of the temperature measuring pool through a temperature sensor;
and setting the target temperature of the circulating water bath, and controlling the temperature fluctuation of the temperature measuring pool to be smaller than a set value through the circulating water bath.
5. The method according to claim 1, wherein the step of providing a hollow pipe in the thermostatic jacket comprises:
the hollow pipeline of the constant-temperature jacket is arranged in a counter-flow manner;
the distance between the hollow pipeline and the outer wall and the inner wall of the constant-temperature jacket is equal, the hollow pipeline on the side surface of the constant-temperature jacket provided with the observation window is in circuitous symmetrical distribution relative to the axis of the observation window, and the hollow pipelines on the side surface, the bottom surface and the top surface of the constant-temperature jacket not provided with the observation window are in uniform distribution with equal distance.
6. The method of claim 4, wherein the step of measuring the temperature of the temperature measuring cell by the temperature sensor comprises:
setting the constant-temperature jacket into a detachable form comprising a constant-temperature jacket top cover and a constant-temperature jacket cylinder;
setting the measuring cell into a detachable connection mode comprising a measuring cell top cover and a measuring cell cylinder;
a plurality of through holes are formed in the top cover of the measuring cell and the top cover of the constant-temperature jacket and used for inserting temperature measuring probes of the temperature sensor;
and measuring the temperatures of different areas of the temperature measuring tank by the temperature measuring probe.
7. The method for measuring refractive index of liquid according to claim 1,
the measuring cell and the constant temperature jacket are hollow isosceles triangular prisms.
8. The method according to claim 1, wherein the measuring cell is made of fused silica, the constant temperature jacket is made of a high thermal conductivity metal material, and a thermal silicone grease is filled between the measuring cell and the constant temperature jacket.
9. The method of claim 1, wherein an observation window is symmetrically disposed at the center of each of the two sidewalls of the thermostatic jacket so that the emitted light beam passes through the observation window within a predetermined angle range from the normal line of the side surface of the thermostatic jacket.
10. The method of claim 1, wherein the opening of the observation window is small inside and large outside.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011125638.XA CN112345493A (en) | 2020-10-20 | 2020-10-20 | Liquid refractive index measuring method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011125638.XA CN112345493A (en) | 2020-10-20 | 2020-10-20 | Liquid refractive index measuring method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112345493A true CN112345493A (en) | 2021-02-09 |
Family
ID=74358883
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011125638.XA Pending CN112345493A (en) | 2020-10-20 | 2020-10-20 | Liquid refractive index measuring method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112345493A (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000026665A1 (en) * | 1998-10-30 | 2000-05-11 | The Research Foundation Of State University Of New York | Method and apparatus for optical measurement of concentration and temperature of liquids |
| CN102830091A (en) * | 2011-06-16 | 2012-12-19 | 江南大学 | Method for measuring liquid refractive index through method of angle of minimum deviation |
| CN105651732A (en) * | 2015-12-31 | 2016-06-08 | 哈尔滨工业大学 | Method for measuring refractive index of liquid by synergistic effect of externally-applied electric field and temperature field |
| CN107870161A (en) * | 2017-12-06 | 2018-04-03 | 西安交通大学 | A kind of method suitable for transparency liquid refractometry |
| CN108169174A (en) * | 2017-12-28 | 2018-06-15 | 中国科学院长春光学精密机械与物理研究所 | A kind of liquid refractivity test device and test method based on the method for minimum deviation angle |
| CN109900660A (en) * | 2017-12-08 | 2019-06-18 | 长光华大基因测序设备（长春）有限公司 | A kind of method and apparatus measuring liquid refractivity |
| CN210533986U (en) * | 2019-09-09 | 2020-05-15 | 常州工程职业技术学院 | Energy-saving constant temperature device for measuring refractive index |
-
2020
- 2020-10-20 CN CN202011125638.XA patent/CN112345493A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000026665A1 (en) * | 1998-10-30 | 2000-05-11 | The Research Foundation Of State University Of New York | Method and apparatus for optical measurement of concentration and temperature of liquids |
| CN102830091A (en) * | 2011-06-16 | 2012-12-19 | 江南大学 | Method for measuring liquid refractive index through method of angle of minimum deviation |
| CN105651732A (en) * | 2015-12-31 | 2016-06-08 | 哈尔滨工业大学 | Method for measuring refractive index of liquid by synergistic effect of externally-applied electric field and temperature field |
| CN107870161A (en) * | 2017-12-06 | 2018-04-03 | 西安交通大学 | A kind of method suitable for transparency liquid refractometry |
| CN109900660A (en) * | 2017-12-08 | 2019-06-18 | 长光华大基因测序设备（长春）有限公司 | A kind of method and apparatus measuring liquid refractivity |
| CN108169174A (en) * | 2017-12-28 | 2018-06-15 | 中国科学院长春光学精密机械与物理研究所 | A kind of liquid refractivity test device and test method based on the method for minimum deviation angle |
| CN210533986U (en) * | 2019-09-09 | 2020-05-15 | 常州工程职业技术学院 | Energy-saving constant temperature device for measuring refractive index |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP2089692B1 (en) | Sensor unit for a surface plasmon resonance (spr) unit | |
| Renk et al. | An evaporating ethanol meniscus—Part I: Experimental studies | |
| Grebenikova et al. | The universal optical method for condition control of flowing medium | |
| Huang et al. | Diffuse interface in a critical fluid mixture | |
| Stengel et al. | Onset of convection in a variable-viscosity fluid | |
| US11590504B2 (en) | Sampling array devices and system for spectral analysis | |
| ZA200401227B (en) | Conductive microtiter plate. | |
| CN110376136B (en) | Device and method for measuring optical constant and morphological parameter of film under high temperature loading | |
| CN112345493A (en) | Liquid refractive index measuring method | |
| JP3330948B2 (en) | Cloud point measurement method and cloud point meter | |
| CN213933587U (en) | Constant temperature measuring cell for refractive index | |
| El-Hawary | Effect of combined free and forced convection on the stability of flow in a horizontal tube | |
| CN109900660A (en) | A kind of method and apparatus measuring liquid refractivity | |
| CN112378859B (en) | Optical constant measuring method and device for quartz glass window polarization effect in-situ calibration | |
| Zhao et al. | Measurements of multicomponent microdroplet evaporation by using Rainbow Refractometer and PDA | |
| Karabegov | Automatic differential prism refractometer for monitoring process liquids | |
| US20150109616A1 (en) | Apparatus for taking an accurate photometric measurement of a liquid | |
| CN219915446U (en) | Test fixture for heat conduction performance of heat conduction interface material of optical module | |
| WO2000026665A1 (en) | Method and apparatus for optical measurement of concentration and temperature of liquids | |
| Muguercia et al. | Measurements of the secondary velocity vector in a 180-degree U-tube using a 2D LDA system with a refractive-index matching technique | |
| CN109142219B (en) | Spectrophotometric multi-wavelength detection device and detection method thereof | |
| Garimella et al. | Heat transfer coefficients for simultaneously developing flow in rectangular tubes | |
| Svyatkina et al. | Condition monitoring of current media using a differential refractometer | |
| SU842531A1 (en) | Device for measuring material thermal physical characteristics | |
| Trifonov Ivanov | Experimental determination of absolute zero temperature |
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 |