Liquid refractive index measuring device

Abstract

The utility model discloses a liquid refractive index measuring device which comprises a broadband low-coherence light source used for providing low-coherence light; the sample arm is used for receiving a part of low-coherence light generated by the broadband low-coherence light source and emitting the low-coherence light to liquid to be detected, and the liquid to be detected generates first reflected light; the reference arm is used for receiving the other part of low-coherence light generated by the broadband low-coherence light source and generating second reflected light, and the second reflected light interferes with the first reflected light to generate an interference signal; the detector is used for collecting the interference signal and sending the interference signal to the control card for analysis and processing; and the container cleaning module is used for cleaning the first container containing the liquid to be detected. According to the utility model, the liquid refractive index is measured by utilizing low-coherence light interference based on the Michelson interferometer, the operation process is simplified, the measurement precision is improved, the repeatability is high, the refractive indexes of different liquids can be accurately detected, and the liquid refractive index measuring device has the advantages of high precision, high stability and the like.

Description

Technical Field

[0001] The utility model belongs to the technical field of liquid refractive index measurement, and in particular relates to a liquid refractive index measuring device. Background Art

[0002] With the advancement of science and technology, humanity's understanding of the properties and microstructure of liquid materials has become increasingly profound, and the essence of liquid material properties has been largely revealed and mastered. Guided by modern materials design theory, researchers have created a variety of new liquid materials with improved performance through new processes, technologies, and equipment. Refractive index is one of the most important physical properties of liquid materials, and it can be used to determine the purity, concentration, and other optical properties of liquids. Currently, several methods for measuring the refractive index of liquids exist, including laser irradiation, diffraction grating, fiber-optic Young's interferometry, grazing incidence, and CCD measurement.

[0003] Chinese patent CN115165803A proposes a method for measuring the refractive index of high-refractive-index and low-transmittance solutions using single-photon detection technology. The method has high accuracy and a wide measurable refractive index range. However, it is necessary to know the bottom length of the liquid container and to use a liquid with a known refractive index as an auxiliary. There are too many external materials and known physical quantities involved. When the liquid to be measured is replaced, the residual liquid in the container is difficult to clean, which can easily cause errors. Chinese patent CN215414992U proposes a total reflection method liquid refractive index measurement experimental instrument. A laser beam is incident on the liquid to be measured, and the dark spot diameter is obtained by reflection on the scale, and the refractive index is then calculated. The structure is simple and easy to operate, but due to the limitation of the total reflection refraction angle, the refractive index range it can measure is limited and it cannot measure larger refractive indices. Other physical quantities that need to be measured are read by the scale on the coordinate axis, which is prone to large errors and low accuracy when reading. The water tank occupies a large area, resulting in a large volume of the entire device. Chinese patent CN217404136U proposes a liquid refractive index measuring device based on the light shielding effect. The laser is shot through the liquid to be measured and the light shielding hole, and is received by the photoelectric sensor. The light intensity and dark spot diameter distribution curve are obtained through the displacement platform, and finally the refractive index of the liquid to be measured is calculated. It has the characteristics of high precision and simple operation, but it is easily affected by external light interference and requires a light shield when used. There are certain requirements for the environment when using it.

[0004] The above patents all have the disadvantages of requiring many physical quantities, limited measurement range, susceptibility to external interference, large measurement errors, and low accuracy.

[0005] Therefore, a non-contact liquid refractive index measuring device is proposed, which is suitable for use in laboratories and can accurately and quickly measure the refractive index of liquids, and has very important practical significance. Utility Model Content

[0006] In order to overcome the above technical defects, the utility model provides a liquid refractive index measuring device, which is suitable for use in a laboratory and can accurately and quickly measure the refractive index of a liquid.

[0007] In order to solve the above problems, the present invention is implemented according to the following technical solutions:

[0008] A liquid refractive index measuring device, comprising:

[0009] A broadband low-coherence light source for providing low-coherence light;

[0010] a sample arm, configured to receive a portion of the low-coherence light generated by the broadband low-coherence light source and emit the light to the liquid to be tested, so that the liquid to be tested generates a first reflected light;

[0011] a reference arm, configured to receive another portion of the low-coherence light generated by the broadband low-coherence light source and generate a second reflected light, wherein the second reflected light interferes with the first reflected light at a coupler to generate an interference signal;

[0012] A detector, used to collect the interference signal and send it to the control card for analysis and processing;

[0013] The container cleaning module is used to clean the first container containing the liquid to be tested.

[0014] Furthermore, the sample arm includes a first collimator for converting a portion of the light generated by the broadband low-coherence light source into parallel light and emitting the parallel light to the liquid to be tested, wherein the first collimator is arranged directly in front of the first container.

[0015] Furthermore, the reference arm includes a second collimator, an optical delay line, and a reflector which are arranged in sequence, and the reflector is arranged perpendicular to the light emission direction of the second collimator.

[0016] Furthermore, the container cleaning module includes a second container for storing pure water, an injection port, a waste liquid tank, a water pump controller, and a water pump. The second container is connected to the injection port, the injection port is connected to the first container, the first container is connected to the waste liquid tank, the water pump is arranged between the first container and the waste liquid tank, and the water pump controller is connected to the water pump.

[0017] Furthermore, the optical delay line is a rotating square prism.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The utility model discloses a liquid refractive index measurement device, comprising a broadband low-coherence light source, a sample arm, a reference arm, a detector, and a container cleaning module. Based on a Michelson interferometer, the device utilizes low-coherence light interference to measure the refractive index of liquids, simplifying the operating process, improving measurement accuracy, and achieving strong repeatability. It can accurately detect the refractive index of different liquids, and has the advantages of high precision and high stability. By using a low-coherence light source to illuminate the liquid to be measured, non-invasive measurements are performed. Furthermore, a container cleaning module is provided to clean residual liquid in the first container after the test is completed, avoiding errors in the next measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, wherein:

[0021] Figure 1 This is an optical path diagram of the liquid refractive index measuring device described in Example 1;

[0022] Figure 2 The structure of the liquid refractive index measuring device described in Example 1 Figure 1 ;

[0023] Figure 3 The structure of the liquid refractive index measuring device described in Example 1 Figure 2 ;

[0024] Figure 4 The structure of the liquid refractive index measuring device described in Example 1 Figure 3 ;

[0025] Marking instructions: 1. Broadband low-coherence light source; 2. Detector; 3. Coupler; 4. Control card; 5. First container; 6. Circulator; 7. First collimator; 8. Second collimator; 9. Optical delay line; 10. Reflector; 11. Trigger device; 12. Second container; 13. Inlet; 14. Waste liquid tank; 15. Water pump controller; 16. Water pump; 17. Data acquisition card; 18. Wavelength division multiplexer; 100. Container cleaning module. DETAILED DESCRIPTION

[0026] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention and are not used to limit the present invention.

[0027] Example 1

[0028] This embodiment discloses a liquid refractive index measuring device, such as Figure 1-4, including a 1310nm broadband low-coherence light source 1, a sample arm, a reference arm, a detector 2 and a container cleaning module 100. The broadband low-coherence light source 1 is connected to the sample arm and the reference arm respectively through optical fibers. The sample arm is connected to the container cleaning module 100, and the sample arm and the reference arm are both connected to the detector 2. The 1310nm broadband low-coherence light source 1 is used to provide low-coherence light; the sample arm is used to receive a portion of the low-coherence light generated by the broadband low-coherence light source 1 and emit it to the liquid to be tested, and the liquid to be tested generates a first reflected light; the reference arm is used to receive another portion of the low-coherence light generated by the broadband low-coherence light source 1 and generate a second reflected light. The second reflected light interferes with the first reflected light at the coupler 3 to generate an interference signal; the detector 2 is used to collect the interference signal and send it to the control card 4 for analysis and processing; the container cleaning module 100 is used to clean the first container 5 containing the liquid to be tested. Specifically, the first container 5 is a transparent container. Specifically, it further includes a circulator 6 , one end of which is connected to the broadband low-coherence light source 1 through an optical fiber, and the other end of the circulator 6 is connected to the detector 2 and the coupler 3 respectively.

[0029] In one embodiment, the sample arm includes a first collimator 7 for converting a portion of the light generated by the 1310 nm broadband low-coherence light source 1 into parallel light and emitting it to the liquid to be tested, wherein the first collimator 7 is arranged directly in front of the first container 5 and is at the same height as the first container 5.

[0030] In one embodiment, the reference arm includes a wavelength division multiplexer 18, a second collimator 8, an optical delay line 9, a reflector 10, and a trigger device 11, which are arranged in sequence. The reflector 10 is arranged perpendicular to the light emission direction of the second collimator 8 to increase the detection depth. In this embodiment, the light outlet of the second collimator 8 is arranged next to the optical delay line 9. Specifically, the optical delay line 9 is a rotating square prism that can achieve fast imaging; compared with traditional instruments using stepper motors, the rotating square prism can provide a faster imaging speed. The trigger device 11 is connected to the control card 4. When the iron sheet under the rotating square prism passes through the trigger device 11, it triggers the trigger device 11, and the trigger device 11 sends a start signal to the control card 4, and the control card 4 starts to collect interference signals.

[0031] In one embodiment, the container cleaning module 100 includes a second container 12 for storing pure water, an injection port 13, a waste liquid tank 14, a water pump controller 15, and a water pump 16. The second container 12 is connected to the injection port 13 through a hose, and the injection port 13 is connected to the first container 5 through a hose. The pure water in the second container 12 is pumped into the injection port 13 and the first container 5, and the first container 5 is connected to the waste liquid tank 14 through a hose. The water pump 16 is arranged between the first container 5 and the waste liquid tank 14, and the water pump controller 15 is connected to the water pump 16 so that the waste liquid in the first container 5 can be pumped into the waste liquid tank 14.

[0032] Specifically, it also includes a data acquisition card 17, which collects the interference signal sent by the detector 2 and forwards it to the control card 4 for analysis and processing.

[0033] The following is an explanation in conjunction with specific implementation methods:

[0034] A portion of the low-coherence light emitted by a 1310nm broadband low-coherence light source enters the sample arm, while the remaining portion enters the reference arm. The height of the first collimator in the sample arm is adjusted so that the light emitted from the first collimator is at the same height as the first container to further improve light return efficiency. The portion of low-coherence light entering the sample arm is collimated by the first collimator and then emitted to the exact center of the first container containing the test liquid. The test liquid generates first reflected light, which then returns to the first collimator along the same path.

[0035] The height of the second collimator in the reference arm is adjusted so that the light exiting the second collimator is at the same height as the optical delay line to improve light return efficiency. Another portion of low-coherence light entering the reference arm passes through the second collimator and the optical delay line, reaching the reflector. The reflector then generates a second reflected light, which then returns to the second collimator along the same path.

[0036] The first reflected light and the second reflected light meet and interfere in the coupler, generating an interference signal. The detector sends the interference signal in the coupler to the control card through the data acquisition card. The control card analyzes and processes the interference signal. The signal data analysis and processing process of the control card is existing technology and will not be repeated here.

[0037] After the liquid measurement is completed, the water pump controller controls the water pump to pump the measured liquid in the first container into the waste liquid pool, and controls the water pump to pump pure water from the second container into the first container to clean the residual liquid in the first container to avoid errors in the next measurement.

[0038] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Therefore, any modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A liquid refractive index measuring device, characterized in that: include: A broadband low-coherence light source for providing low-coherence light; a sample arm, configured to receive a portion of the low-coherence light generated by the broadband low-coherence light source and emit the light to the liquid to be tested, so that the liquid to be tested generates a first reflected light; a reference arm, configured to receive another portion of the low-coherence light generated by the broadband low-coherence light source and generate a second reflected light, wherein the second reflected light interferes with the first reflected light to generate an interference signal; A detector, used to collect the interference signal and send it to the control card for analysis and processing; The container cleaning module is used to clean the first container containing the liquid to be tested.

2. The liquid refractive index measuring device according to claim 1, characterized in that: The sample arm includes a first collimator for converting a portion of light generated by the broadband low-coherence light source into parallel light and emitting the parallel light to the liquid to be measured, wherein the first collimator is arranged right in front of the first container.

3. The liquid refractive index measuring device according to claim 1, characterized in that: The reference arm includes a second collimator, an optical delay line, and a reflector, which are arranged in sequence. The reflector is arranged perpendicular to the light emitting direction of the second collimator.

4. The liquid refractive index measuring device according to claim 1, characterized in that: The container cleaning module includes a second container for storing pure water, an injection port, a waste liquid tank, a water pump controller, and a water pump. The second container is connected to the injection port, the injection port is connected to the first container, the first container is connected to the waste liquid tank, the water pump is arranged between the first container and the waste liquid tank, and the water pump controller is connected to the water pump.

5. The liquid refractive index measuring device according to claim 4, characterized in that: The optical delay line is a rotating square prism.

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