A method and device for measuring the optical rotation rate of a solution

Abstract

The present invention discloses a method for measuring the optical rotation rate of a solution, comprising the following steps: A light source emits light, the light passes through a polarizer and then enters a container filled with the solution to be measured. After the light exits the container, it passes through an analyzer and finally enters a light intensity sensor connected to a control device. A filter is provided between the light source and the light intensity sensor. Record the angle between the transmission axis of the analyzer in the analyzer and the transmission axis of the polarizer in the polarizer. Inject the solution to be measured with a concentration of C into the container. As the liquid column length in the container gradually increases, the light intensity sensor recognizes that the light intensity gradually changes. Then, adjust the liquid column length in the container so that the light intensity is at the maximum value, and record the liquid column length in the container at this time, which is the optical path l. Use the formula to calculate the optical rotation rate of the solution to be measured. The present invention also discloses a device for measuring the optical rotation rate of a solution. The present invention measures the optical rotation rate by changing the optical path instead of the angle of the analyzer, with simple operation, convenient reading and small error.

Description

Technical Field

[0001] The present invention relates to the technical field of solution optical rotation rate detection, and more specifically, to a method and device for measuring the optical rotation rate of a solution. Background Art

[0002] When linearly polarized light passes through the solution of certain substances, the vibration plane of the polarized light will rotate a certain angle around the light propagation direction, and this phenomenon is called optical rotation. The optical rotation rate, also known as the optical rotation degree and specific rotation, is a constant related to the type of optically active solution, temperature, and the frequency of light. By measuring the optical rotation rate of a substance, the purity and concentration of the substance can be determined. Usually, a polarimeter is used to measure the optical rotation degree of a substance, and then the optical rotation rate is calculated.

[0003] There is a simple optical rotation degree measurement device. Adjust the electronic light intensity receiver and the laser to the same height, and adjust the laser so that the laser propagates horizontally. Introduce a polarizer into the optical path and adjust the polarizer to make the reading of the light intensity receiver maximum. Introduce an analyzer into the optical path and adjust the analyzer to make the reading of the light intensity receiver maximum, and record the angular value q1 of the analyzer at this time. Introduce the sample into the optical path and adjust the analyzer to make the reading of the light intensity receiver maximum, and record the angular value q2 of the analyzer at this time. The optical rotation degree = q2 - q1.

[0004] However, in the above solution, it is still necessary to adjust the angle of the analyzer and take readings. During the use of the analyzer, the reading disk is prone to deviation, resulting in large reading errors. Moreover, the reading process of the vernier caliper is complex and prone to errors when taking readings. At the same time, when loading the solution to be measured into the container, it is necessary to avoid generating bubbles as much as possible, which is difficult to operate and easily causes the solution to leak out, polluting the outer wall of the container and the experimental table. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies of large reading errors and complex operation when using the existing optical rotation degree measurement device, and provide a method and device for measuring the optical rotation rate of a solution. The present invention tests the optical rotation rate by changing the optical path rather than the angle of the analyzer, with simple operation, convenient reading, and small errors.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A method for measuring the optical rotation rate of a solution includes the following steps:

[0008] S1: A light source emits light, the light first passes through a polarizer and then enters a container filled with the solution to be measured. The incident surface and the exit surface of the container are both light-transmitting surfaces. After the light exits from the container, it passes through an analyzer, and finally the light enters a light intensity sensor connected to a control device. Moreover, a filter for the light to pass through is provided between the light source and the light intensity sensor, and the included angle between the light-transmitting axis of the analyzer in the analyzer and the light-transmitting axis of the polarizer in the polarizer is recorded.

[0009] S2: Inject the test solution with a concentration of C into the container. As the liquid column length in the container gradually increases, the light intensity sensor recognizes that the light intensity gradually changes and is displayed in the control device. Then, adjust the liquid column length in the container until the light intensity displayed in the control device reaches the maximum value, and record the liquid column length in the container at this time, which is the optical path l.

[0010] S3: Use the formula to calculate the specific rotation of the test solution.

[0011] Specific rotation where α is the specific rotation, which is a constant related to the type of optically active solution, temperature, and frequency of light. Therefore, the specific rotation represents the specific rotation at a certain temperature t and a certain wavelength λ. Among them, t represents the temperature during the experiment, unit: °C; λ is the wavelength selected by the filter, unit: nm; is the angle between the transmission axis of the analyzer polarizer and the transmission axis of the polarizer in the polarizer, unit: °; l is the optical path, that is, the solution height, unit: cm; C is the concentration of the test solution, unit: g / 100ml.

[0012] The present invention measures the specific rotation α by keeping and C relatively determined and changing the optical path l. Compared with measuring the angle, the linear length optical path l is easier to measure than the angle and the error generated will be smaller. During the test, as the test solution is continuously injected into the container, the liquid column length in the container continuously increases, and at the same time, the light intensity sensed by the light intensity sensor will continuously increase until it reaches a maximum value. Then, as the liquid column in the container continues to increase, the light intensity will gradually decrease. At this time, a certain amount of the test solution needs to be drawn out of the container, and the liquid column length at this time just makes the light intensity reach the maximum value, and record the liquid column length l at this time. And, record the angle between the transmission axis of the analyzer polarizer and the transmission axis of the polarizer in the polarizer during this test and the concentration of the test solution, then the specific rotation α can be calculated through the formula

[0013] At the same time, record the temperature t during the test and the wavelength λ that the filter selected in the filter can transmit, that is, when the temperature is t and the wavelength is λ, the specific rotation of the solution is After the light emits from the light source and before entering the light intensity sensor, use a filter at any position on the light propagation path, and the obtained specific rotation is the same. The position of the filter does not affect the experimental results. Filters with different transmission wavelengths can be used, and repeat the above steps to obtain the specific rotation of the same solution at different wavelengths.

[0014] Further, after step S3, the following steps are further included:

[0015] S4: Repeat steps S1 to S3; or use different polarizers to change the angle between the transmission axes of the polarizer and the analyzer; or use different filters to change the wavelength, and then repeat steps S1 to S3 for multiple experiments. Multiple experiments can be repeated under the same conditions to avoid accidental errors affecting the test results. Different polarizers can also be used or the angle of the polarizer can be rotated to change the angle, and then repeated experiments are carried out. Since the specific rotation α is a constant related to the type of solution, temperature, and the frequency of light, when the angle is changed, the optical path length l will also change, and the finally measured specific rotation α should still be the same. In this way, multiple groups of data are measured, accidental errors are eliminated, and the remaining data are averaged to improve the accuracy.

[0016] Before step S1, the following steps are further included: S0: Prepare a test solution with a concentration of C, rinse the container with the test solution, and select a polarizer with different transmission axes according to the solution concentration. After each test, the container needs to be cleaned. After cleaning, in order to avoid dilution of the test solution due to water residue, the container needs to be rinsed with the prepared test solution. At the same time, since the specific rotation

[0017] Under the condition that other conditions remain unchanged, when the concentration C of the test solution is relatively large, in order to make the phenomenon more obvious during the test, a polarizer that can make

[0018] larger can be selected. However, since the length of the container is fixed and l cannot exceed the range of the container, when the concentration of the test solution is relatively small, in order to avoid l exceeding the range of the container when the light intensity reaches the maximum value, a polarizer that can make

[0019] smaller can be selected. In step S2, the test solution is slowly injected from the bottom of the container, and the light intensity sensor is based on the reading when the liquid level of the test solution is calm. If the liquid level in the container fluctuates, the length of the liquid column will change. At this time, the length of the liquid column is difficult to read or errors will occur. Therefore, it is necessary to wait until the liquid level is calm before taking readings. In order to avoid fluctuations in the liquid level in the container, the test solution is slowly injected from the bottom of the container, and the liquid level in the container remains stable all the time, saving the time for waiting for the liquid level to calm down and making the test process faster. If the liquid level in the container fluctuates, the length of the liquid column will change. At this time, the length of the liquid column is difficult to read or errors will occur. Therefore, it is necessary to wait until the liquid level is calm before taking readings. In order to avoid fluctuations in the liquid level in the container, the test solution is slowly injected from the bottom of the container, and the liquid level in the container remains stable all the time, saving the time for waiting for the liquid level to calm down and making the test process faster.

[0020] In step S2, the test solution is slowly injected from the bottom of the container, and the light intensity sensor is based on the reading when the liquid level of the test solution is calm.

[0021] If the liquid level in the container fluctuates, the length of the liquid column will change. At this time, the length of the liquid column is difficult to read or errors will occur. Therefore, it is necessary to wait until the liquid level is calm before taking readings. In order to avoid fluctuations in the liquid level in the container, the test solution is slowly injected from the bottom of the container, and the liquid level in the container remains stable all the time, saving the time for waiting for the liquid level to calm down and making the test process faster.

[0022] A measuring device for the optical rotation rate of a solution, comprising a container that can accommodate the solution to be measured and allow light to pass through, a light source for generating light, a polarizer for converting the light generated by the light source into polarized light, an analyzer for analyzing the polarized light, a light intensity sensor for measuring the light intensity of the light filtered by the filter, a control device electrically connected to the light intensity sensor, and a filter. The light incident surface and the light exit surface of the container are both light-transmitting surfaces. The light generated by the light source sequentially passes through the polarizer, the container, and the analyzer and finally enters the light intensity sensor, and the propagation direction of the light is parallel to the axis of the container. A filter for filtering the light into a specific wavelength is also provided between the light source and the light intensity sensor.

[0023] The light generated by the light source needs to sequentially pass through the polarizer, one end of the container, the solution to be measured in the container, the other end of the container, and the analyzer, and pass through the filter once at any position between the light source and the light intensity sensor, and finally enter the photosensitive surface of the light intensity sensor. The light intensity sensor transmits the sensed information to the control device, and the control device displays the light intensity. The control device can be a computer or the like. In this measuring device for the optical rotation rate of the solution, the included angle between the transmission axis of the polarizing sheet in the polarizer and the transmission axis of the analyzing sheet in the analyzer is a known parameter. When measuring the optical rotation rate of the solution, the solution to be measured is gradually injected into the solution container, and the length of the liquid column in the container, that is, the optical path l, is changed, so that the polarized light passing through the polarizer passes through a certain length of the solution liquid column and reaches the analyzer. The light intensity sensor senses the light intensity passing through the filter as the maximum value. Finally, given that the concentration of the solution to be measured is C, using the formula the optical rotation rate α of the solution can be calculated.

[0024] The container in this measuring device for the optical rotation rate of the solution can be vertically placed with its own axis parallel to the vertical direction, so that the light source and the polarizer are located below the container, and the analyzer, the filter, and the light intensity sensor are all located above the container; the container can also be horizontally placed with its own axis parallel to the horizontal direction. At this time, only a piston needs to be provided in the container to make the solution to be measured in the container form a cylindrical liquid column, and the moving direction of the piston is consistent with the axis direction of the container.

[0025] The filter can be located between the light source and the polarizer, or between the polarizer and the container, or between the container and the analyzer, or between the analyzer and the light intensity sensor, which does not affect the implementation of this solution. The solution to be measured can be gradually injected into the container manually or by a pump, which does not affect the implementation of this solution.

[0026] Further, it further includes an adjusting device for adjusting the position of the light intensity sensor. The analyzer includes a plurality of sector analyzer plates with different light transmission axis directions provided at one end of the container. The sector analyzer plates are spliced into a circular analyzer plate. The adjusting device adjusts the position of the light intensity sensor to align the photosensitive surface of the light intensity sensor with different sector analyzer plates.

[0027] One polarizer plate in the polarizer and one analyzer plate in the analyzer are provided respectively, so that the included angle between the light transmission axis of the analyzer plate in the analyzer and the light transmission axis of the polarizer plate in the polarizer is not adjustable, and this measuring device for the specific rotation of the solution can also be used. However, in order to be adjustable for multiple tests, or in order to enable a larger range of solution concentrations to be measured, the analyzer plate in the analyzer can be made replaceable. In this solution, sector analyzer plates with different light transmission axis directions are spliced into a circular analyzer plate, and light is allowed to pass through the circular analyzer plate. When selecting sector analyzer plates with different light transmission axes, only by moving the position of the light intensity sensor through the adjusting device so that the photosensitive surface of the light intensity sensor is aligned with the corresponding sector analyzer plate, the change can be achieved. The included angles between the light transmission axes of different sector analyzer plates and the light transmission axis of the polarizer plate in the polarizer can be set in advance and marked. For example, it includes four sector analyzer plates with a central angle of 90° spliced into a circular analyzer plate. The included angles between the light transmission axes of the four sector analyzer plates and the light transmission axis of the polarizer are 45°, 90°, 135°, and 180° respectively. Other combinations can also be used without affecting the implementation of this solution.

[0028] In the above solution, the light intensity sensor is moved while the circular analyzer plate cannot move. If the analyzer includes a turntable base and a circular analyzer plate, and the circular analyzer plate can rotate around its own axis in the turntable base, and the light intensity sensor is fixed and the circular analyzer plate is rotated, so that different sector analyzer plates are rotated to the photosensitive surface of the light intensity sensor, the effect of switching the analyzer plate can also be achieved. However, after the analyzer plate rotates, the included angle needs to be added or subtracted by the corresponding angle. Or the analyzer includes a common analyzer plate and an analyzer plate fixing device, and the light intensity sensor is also fixed. When the analyzer plate needs to be replaced, the common analyzer plate can be directly disassembled and a new analyzer plate can be installed.

[0029] Further, the adjusting device includes a bracket, a cross clamp provided on the bracket, and a fixing clamp for clamping the light intensity sensor. One end of the cross clamp is clamped on the bracket, and the other end clamps the fixing clamp. The light intensity sensor is clamped and fixed by the fixing clamp.

[0030] This solution uses a device similar to the iron stand and cross clamp in a laboratory to fix the light intensity sensor, and it is also convenient to move the light intensity sensor to different sector polarizers.

[0031] The adjusting device can be an iron stand and an iron clamp. The iron clamp can be moved and fixed on the iron stand, and the light intensity sensor is clamped and fixed by the iron clamp. The adjusting device can also be an annular chute and a sliding seat provided on the annular chute. The light intensity sensor is fixed on the sliding seat. Just sliding the sliding seat to the corresponding sector polarizer can realize the switching of the polarizer. The adjusting device can also be other structures without affecting the implementation of this solution.

[0032] Further, the adjusting device includes a bracket, an annular slide rail provided on the bracket, and a slider provided on the annular slide rail. The light intensity sensor is provided on the slider, and the axis of the annular slide rail is parallel to the container.

[0033] The light intensity sensor can move along the slide rail. In this way, the light intensity sensor can move to different sector polarizers to realize the switching of different polarizers. A device for fixing the slider on the annular slide rail can also be provided on the shaping slide rail or the slider.

[0034] Further, it also includes a liquid storage device for storing the solution to be measured and a pump. The liquid storage device is connected to the container, and the pump can pump the solution to be measured in the liquid storage device into the container or pump it out of the container.

[0035] In this solution, the prepared solution to be measured is used to rinse the liquid storage device and the container, and then the solution to be measured is stored in the liquid storage device. The pump is used to pump the solution to be measured in the liquid storage device into the container or pump the solution to be measured out of the container.

[0036] The pump for the container can be manually controlled to pump the solution to be measured in or out, but it is difficult to manually operate the start and stop of the pump to make the liquid level in the container just stay at the position where the light intensity reaches the maximum value. Therefore, a control device can be used to control the operation of the pump, and the control device is also connected to the light intensity sensor. During the test, as the control device continuously pumps the solution to be measured into the container through the pump, the light intensity gradually increases to a maximum value and then gradually decreases. The control device records this maximum value, and then controls the pump to pump the solution to be measured out of the container so that the light intensity reaches the maximum value again.

[0037] Further, a liquid inlet is provided at the bottom of the container, an outlet is provided at the bottom of the liquid storage device, a liquid delivery pipe is provided between the liquid inlet and the outlet, an air inlet is provided at the top of the liquid storage device, and the pump is an air pump. The air nozzle of the air pump is detachably connected to the air inlet.

[0038] In this solution, the pump is an air pump, which presses the solution to be measured into the container or extracts it from the container by changing the air pressure in the liquid storage container. The liquid inlet and the liquid outlet are interconnected through an infusion tube. A switch may be provided on the infusion tube. The infusion tube may be a rubber tube, and the switch may be a sealing clip. This solution is the structure when the container is placed vertically. The solution is pressed into or extracted from the bottom of the container to avoid fluctuations in the liquid level affecting the light propagation path. However, when the container is placed horizontally and there is a piston inside, the liquid inlet should be provided at one end of the container.

[0039] Further, the container is a cylinder. The light incident surface and the light exit surface of the container are the two end faces of the container. The side wall of the container is made of a transparent material, and a scale for displaying the liquid level height is provided on the outer side wall of the container.

[0040] The scale on the outer side wall of the container is used to read the length of the liquid column in the container.

[0041] When the container is placed vertically, a liquid level sensor connected to the control device can also be used to measure the height of the liquid column. A piston may also be provided in the container, so that the container can be placed vertically or horizontally. At the same time, a displacement sensor can be provided on the piston, or other methods can be used to measure the length of the liquid column.

[0042] Further, the filter includes a filter seat and a filter plate. The filter plate is detachably connected to the filter seat. When the filter plate needs to be replaced, the original filter plate is directly removed and a new filter plate is installed. The connection between the filter seat and the filter plate can be a threaded connection, a snap connection, etc., which does not affect the implementation of this solution.

[0043] Further, the light-shielding plate is circular. The filter plate includes a plurality of sector-shaped filter plates with different transmissible wavelengths. The filter seat includes an annular fixing seat provided on the bracket and a light-shielding cover provided in the inner ring of the annular fixing seat. A sector-shaped light-transmitting window is opened on the light-shielding cover. The light-shielding plate is provided in the inner ring of the annular fixing seat and is coaxial with the annular fixing seat. The outer peripheral side wall of the light-shielding plate is slidably connected to the inner peripheral side wall of the annular fixing seat, and the light-shielding plate can rotate around the axis of the annular fixing seat; or, the outer peripheral side wall of the filter plate is slidably connected to the inner peripheral side wall of the annular fixing seat, and the filter plate can rotate around its own axis.

[0044] By changing the sector-shaped filter plate facing the light-transmitting window on the light-shielding cover, the filter can select light of different wavelengths to adapt to different solutions to be measured, or different wavelengths of light can be switched for multiple measurements.

[0045] Compared with the prior art, the beneficial effects of the present invention are:

[0046] (1) When measuring the optical rotation rate of a solution in the present invention, the concentration C of the solution to be measured and the included angle between the transmission axis of the analyzer in the analyzer and the transmission axis of the polarizer in the polarizer are known conditions. By measuring the length of the liquid column in the container, i.e., the optical path l, when the light intensity transmitted through the analyzer is at a maximum value, the optical rotation rate α of the solution can be calculated. In this way, by measuring the liquid column height instead of the included angle the operation of measuring the linear distance is simpler and more convenient, and the error is smaller.

[0047] (2) Using a pump to pump the solution to be measured in the reservoir into the container or pump it out of the container, the structure is simple and the operation is convenient. Pumping the solution to be measured into or out of the container at the bottom can avoid generating ripples on the liquid surface.

[0048] (3) In the present invention, the included angle between the transmission axis of the analyzer in the analyzer and the transmission axis of the polarizer in the polarizer can be a settable parameter. By switching the analyzer with different transmission axes, multiple tests can be carried out to reduce errors. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 is a flowchart of the measurement method of the present invention;

[0050] Figure 2 is a schematic diagram of the light propagation of the present invention;

[0051] Figure 3 is a schematic diagram of the overall structure of the present invention;

[0052] Figure 4 is a schematic diagram of the filter structure of the present invention;

[0053] Figure 5 is a schematic diagram of the adjustment device structure of Embodiment 5 of the present invention.

[0054] The illustration marks are explained as follows:

[0055] 1 - Light source, 2 - Polarizer, 3 - Container, 31 - Liquid inlet, 4 - Analyzer, 41 - Sector analyzer, 5 - Light intensity sensor, 6 - Filter, 61 - Ring fixed seat, 62 - Light-shielding cover, 63 - Translucent window, 7 - Reservoir, 71 - Liquid delivery pipe, 8 - Pump, 9 - Adjustment device, 91 - Bracket, 92 - Cross clamp, 93 - Fixed clamp, 94 - Ring slide rail, 95 - Slide block. DETAILED DESCRIPTION OF THE INVENTION

[0056] The present invention will be further described below in conjunction with specific embodiments. Among them, the attached drawings are only for illustrative purposes, showing only schematic diagrams, not physical diagrams, and should not be construed as a limitation to this patent; in order to better illustrate the embodiments of the present invention, some components in the attached drawings will be omitted, enlarged or reduced, which does not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the attached drawings may be omitted.

[0057] In the attached drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", etc. indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the attached drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the attached drawings are only for illustrative purposes and should not be construed as a limitation to this patent. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0058] Embodiment 1

[0059] As Figures 1 to 3 shown, a method for measuring the optical rotation rate of a solution includes the following steps:

[0060] S1: The light source 1 emits light, and the light first passes through the polarizer 2 and then enters the container 3 filled with the solution to be measured. The incident surface and the exit surface of the container 3 are both light-transmitting surfaces. After the light exits from the container 3, it passes through the analyzer 4, and finally the light enters the light intensity sensor 5 connected to the control device. Moreover, a filter 6 for the light to pass through is provided between the light source 1 and the light intensity sensor 5, and the included angle between the transmission axis of the analyzer plate in the analyzer 4 and the transmission axis of the polarizer plate in the polarizer 2 is recorded.

[0061] S2: Inject the solution to be measured with a concentration of C into the container 3. As the liquid column length in the container 3 gradually increases, the light intensity sensor 5 recognizes that the light intensity gradually changes and is displayed in the control device. Then, adjust the liquid column length in the container 3 to the maximum value of the light intensity displayed by the control device, and record the liquid column length in the container 3 at this time, that is, the optical path l.

[0062] S3: Use the formula to calculate the optical rotation rate of the solution to be measured.

[0063] Optical rotation rate where α is the optical rotation rate, which is a constant related to the type of the optically active solution, temperature, and the frequency of light. Therefore, the optical rotation rate represents the optical rotation rate at a certain temperature t and a certain wavelength λ, where t represents the temperature during the experiment, unit: °C; λ is the wavelength selected by the filter, unit: nm; is the angle between the transmission axis of the analyzer in the analyzer 4 and the transmission axis of the polarizer in the polarizer 2, unit: °; l is the optical path, that is, the height of the solution, unit: cm; C is the concentration of the solution to be measured, unit: g / 100ml.

[0064] This invention measures the optical rotation rate α by keeping and C relatively constant and changing the optical path l. Compared with measuring the angle the linear length of the optical path l is easier to measure than the angle and the error generated will be smaller. During the test, as the solution to be measured is continuously injected into the container 3, the length of the liquid column in the container 3 continuously increases, and at the same time, the light intensity sensed by the light intensity sensor 5 will continuously increase until it reaches a maximum value. Then, as the liquid column in the container 3 continues to increase, the light intensity will gradually decrease. At this time, a certain amount of the solution to be measured needs to be drawn out of the container 3, and the length of the liquid column at this time just makes the light intensity reach the maximum value, and record the length l of the liquid column at this time. And, record the angle between the transmission axis of the analyzer in the analyzer 4 and the transmission axis of the polarizer in the polarizer 2 during this test and the concentration of the solution to be measured, then the optical rotation rate α can be calculated through the formula

[0065] At the same time, record the temperature t during the test and the wavelength λ that the filter selected in the filter 6 can transmit, that is, when the temperature is t and the wavelength is λ, the optical rotation rate of the solution is After the light rays are emitted from the light source 1 and before entering the light intensity sensor 5, using the filter 6 at any position on the light propagation path, the obtained optical rotation rate is the same, and the position of the filter 6 does not affect the experimental results. Different filters with different transmission wavelengths can be used, and the above steps can be repeated to obtain the optical rotation rates of the same solution at different wavelengths.

[0066] After step S3, the following steps are further included:

[0067] S4: Repeat steps S1 to S3; or use different analyzer plates to change the angle between the transmission axes of the analyzer plate and the polarizer plate; or use different filters to change the wavelength, and then repeat steps S1 to S3 to conduct multiple experiments.

[0068] The experiment can be repeated multiple times under the same conditions to avoid the influence of accidental errors on the test results. Different analyzer plates can also be used or the angle of the analyzer plate can be rotated to make change and then repeat the experiment. Since the optical rotation rate α is a constant related to the type of solution, temperature, and frequency of light, changing the angle The optical path length l will also change, and the measured optical rotation rate α should still be the same. By measuring multiple sets of data in this way, eliminating accidental errors, and taking the average of the remaining data, the accuracy can be improved.

[0069] Before step S1, the following steps are also included:

[0070] S0: Prepare a test solution with a concentration of C, rinse container 3 with the test solution, and select an analyzer with a different light transmission axis according to the solution concentration.

[0071] After each test, container 3 needs to be cleaned. After cleaning, to avoid dilution of the test solution due to water residue, it is necessary to rinse container 37 with the prepared test solution. At the same time, due to the optical rotation rate Under the condition that other conditions remain unchanged, when the concentration C of the test solution is relatively large, in order to make the phenomenon more obvious during the test, an analyzer that can make larger can be selected. However, since the length of container 3 is fixed and l cannot exceed the range of container 3, if the concentration of the test solution is relatively small, in order to avoid l exceeding the range of container 3 when the light intensity reaches the maximum value, an analyzer that can make smaller can be selected.

[0072] The control device controls the pump 8 to pump the test solution into or out of container 3 so that the pipeline intensity recognized by the control device is the maximum value.

[0073] In step S2, the test solution is slowly injected from the bottom of container 3, and the light intensity sensor 5 takes the reading when the liquid level of the test solution is calm.

[0074] If the liquid level in container 3 fluctuates, the length of the liquid column will change. At this time, the length of the liquid column is difficult to read or errors will occur. Therefore, it is necessary to wait until the liquid level is calm before taking the reading. To avoid the liquid level fluctuation in container 3, the test solution is slowly injected from the bottom of container 3, and the liquid level in container 3 remains stable all the time, saving the time to wait for the liquid level to be calm and making the test process faster.

[0075] Embodiment 2

[0076] As Figures 1 to 4As shown in the figure, a measuring device for the optical rotation rate of a solution includes a container 3 that can accommodate the solution to be measured and allow light to pass through, a light source 1 for generating light, a polarizer 2 for converting the light generated by the light source 1 into polarized light, an analyzer 4 for analyzing the polarized light, a light intensity sensor 5 for measuring the light intensity of the light filtered by the filter, a control device electrically connected to the light intensity sensor 5, and a filter 6. The light incident surface and the light exit surface of the container 3 are both light-transmitting surfaces. The light generated by the light source 1 sequentially passes through the polarizer 2, the container 3, and the analyzer 4 and finally enters the light intensity sensor 5, and the propagation direction of the light is parallel to the axis of the container 3. A filter for filtering the light into a specific wavelength is also provided between the light source 1 and the light intensity sensor 5.

[0077] The light generated by the light source 1 needs to sequentially pass through the polarizer 2, one end of the container 3, the solution to be measured in the container 3, the other end of the container 3, and the analyzer 4, and pass through the filter 6 once at any position between the light source 1 and the light intensity sensor 5, and finally enter the photosensitive surface of the light intensity sensor 5. The light intensity sensor 5 transmits the sensed information to the control device, and the control device displays the light intensity. The control device can be a computer or the like. In this measuring device for the optical rotation rate of the solution, the included angle between the transmission axis of the polarizing sheet in the polarizer 2 and the transmission axis of the analyzing sheet in the analyzer 4 is a known parameter. When measuring the optical rotation rate of the solution, the solution to be measured is gradually injected into the container 3, and the length of the liquid column in the container 3 is changed so that the polarized light passing through the polarizer 2 reaches the analyzer 4 after passing through a certain length of the solution liquid column, and the light intensity sensor 5 senses the maximum light intensity passing through the filter 6.

[0078] In this embodiment, the container 3 in the measuring device for the optical rotation rate of the solution is vertically placed with its own axis parallel to the vertical direction, so that the light source 1 and the polarizer 2 are located below the container 3, and the analyzer 4, the filter 6, and the light intensity sensor 5 are all located above the container 3. In this embodiment, the filter 6 is between the analyzer 4 and the light intensity sensor 5.

[0079] It further includes an adjusting device 9 for adjusting the position of the light intensity sensor 5. The analyzer 4 includes a plurality of sector-shaped analyzing sheets 41 with different transmission axis directions provided at one end of the container. The sector-shaped analyzing sheets 41 are spliced into a circular analyzing sheet, and the adjusting device 9 adjusts the position of the light intensity sensor 5 to align the photosensitive surface of the light intensity sensor 5 with different sector-shaped analyzing sheets 41.

[0080] One polarizing sheet in the polarizer 2 and one analyzing sheet in the analyzer 4 are provided respectively, so that the included angle between the transmission axis of the analyzing sheet in the analyzer 4 and the transmission axis of the polarizing sheet in the polarizer 2 is not adjustable, and this measuring device for the optical rotation rate of the solution can also be used. But in order to make It can be adjusted to conduct multiple tests, or in order to enable a larger range of solution concentrations to be tested, the polarizer in the analyzer 4 can be made replaceable. In this solution, sector polarizers 41 with different light transmission axis directions are spliced into a circular polarizer, and light is passed through the circular polarizer. When selecting sector polarizers 41 with different light transmission axes, it is only necessary to move the position of the light intensity sensor 5 through the adjusting device 9 so that the light-sensitive surface of the light intensity sensor 5 is aligned with the corresponding sector polarizer 41, and the following can be achieved changes. The angles between the light transmission axes of different sector polarizers 41 and the light transmission axis of the polarizer in the polarizer 2 can be set in advance and marked. For example, four sector polarizers 41 with a central angle of 90° are spliced into a circular polarizer, and the angles between the light transmission axes of the four sector polarizers 41 and the light transmission axis of the polarizer 2 are 45°, 90°, 135°, and 180° respectively. Other combinations can also be used without affecting the implementation of this solution.

[0081] In the above solution, the polarizer in the polarizer 2 is not changed, but the polarizer in the analyzer 4 is changed. Of course, by changing the polarizer in the polarizer 2 while the polarizer in the analyzer 4 remains unchanged, or by changing both the polarizer in the polarizer 2 and the polarizer in the analyzer 4, the test result of the specific rotation rate is not affected.

[0082] In the above solution, the light intensity sensor 5 is moved while the circular polarizer cannot move. If the analyzer 4 includes a turntable base and a circular polarizer, the circular polarizer can rotate around its own axis in the turntable base. By fixing the light intensity sensor 5 and rotating the circular polarizer, different sector polarizers 41 can be rotated to the light-sensitive surface of the light intensity sensor 5, which can also achieve the effect of switching the polarizer. Or the analyzer 4 includes a common polarizer and a polarizer fixing device, and the light intensity sensor 5 is also fixed. When the polarizer needs to be replaced, the common polarizer can be directly disassembled and a new polarizer can be installed.

[0083] The adjusting device 9 includes a bracket 91, a cross clamp 92 provided on the bracket 91, and a fixing clamp 93 for clamping the light intensity sensor 5. One end of the cross clamp 92 is clamped on the bracket 91, and the other end clamps the fixing clamp 93. The light intensity sensor 5 is clamped and fixed by the fixing clamp 93.

[0084] This solution uses a structure similar to an iron stand and a cross clamp 92 in a laboratory to fix the light intensity sensor 5, and at the same time, it is also convenient to move the light intensity sensor 5 to different sector polarizers 41.

[0085] The adjusting device 9 can be an iron stand and an iron clamp. The iron clamp can be moved and fixed on the iron stand. The light intensity sensor 5 is clamped and fixed by the iron clamp. The adjusting device 9 can also be an annular sliding groove and a sliding seat arranged on the annular sliding groove. The light intensity sensor 5 is fixed on the sliding seat. Just sliding the sliding seat into the corresponding sector polarizer 41 can realize the switching of the polarizer. The adjusting device 9 can also be other structures, which does not affect the implementation of this solution.

[0086] It also includes a liquid storage device 7 for storing the solution to be measured and a pump 8. The liquid storage device 7 is communicated with the container 3. The pump 8 can pump the solution to be measured in the liquid storage device 7 into the container 3 or draw it out from the container 3.

[0087] In this solution, the prepared solution to be measured is used to rinse the liquid storage device 7 and the container 3, and then the solution to be measured is stored in the liquid storage device 7. The pump 8 is used to pump the solution to be measured in the liquid storage device into the container or draw the solution to be measured out of the container.

[0088] The bottom of the container 3 is provided with a liquid inlet 31, and the bottom of the liquid storage device 7 is provided with a liquid outlet. A liquid delivery pipe 71 is arranged between the liquid inlet 31 and the liquid outlet. The top of the liquid storage device 7 is provided with an air inlet. The pump 8 is an air pump, and the air nozzle of the air pump is detachably connected to the air inlet.

[0089] In this embodiment, the pump 8 is manually controlled to pump the solution to be measured in the container 3 into or out of the container, and at the same time, observe the light intensity displayed by the control device, and adjust the liquid level height in the container 3 to the maximum light intensity.

[0090] The pump 8 is an air pump, and the solution to be measured is pressed into the container 3 or drawn out of the container 3 by changing the air pressure in the liquid storage device 7. The liquid inlet 31 and the liquid outlet are communicated with each other through the liquid delivery pipe 71. A switch can be arranged on the liquid delivery pipe 71. The liquid delivery pipe 71 can be a rubber pipe, and the switch can be a sealing clip. This solution is the structure when the container 3 is placed vertically. The solution is pressed into or drawn out from the bottom of the container 3 to avoid the liquid level fluctuation affecting the light propagation path.

[0091] The container 3 is a cylinder. The light incident surface and the light exit surface of the container 3 are the two end faces of the container 3. The side wall of the container 3 is made of a transparent material. A scale for displaying the liquid level height is arranged on the outer side wall of the container 3. The scale on the outer side wall of the container 3 is used to read the length of the liquid column in the container 3.

[0092] When the container 3 is placed vertically, a liquid level sensor connected to the control device can also be used to measure the height of the liquid column. A piston can also be arranged in the container 3. In this way, the container 3 can be placed vertically or horizontally. At the same time, a displacement sensor can be arranged on the piston, or other methods can be used to measure the length of the liquid column.

[0093] The filter 6 includes a filter base and a filter plate. The light-shielding plate is circular, the filter plate includes a plurality of sector-shaped filter plates with different transmissible wavelengths, the filter base includes an annular fixing base 61 provided on the bracket 91 and a light-shielding cover 62 provided in the inner ring of the annular fixing base 61. A sector-shaped light-transmitting window 63 is provided on the light-shielding cover 62. The light-shielding plate is arranged coaxially with the annular fixing base 61 in the inner ring of the annular fixing base 61. The outer peripheral side wall of the filter plate is slidably connected to the inner peripheral side wall of the annular fixing base 61, and the filter plate can rotate around its own axis.

[0094] By changing the sector-shaped filter plate facing the light-transmitting window 63 on the light-shielding cover 62, the filter 6 can select light of different wavelengths to adapt to different test solutions to be measured, or different wavelengths of light can be switched for multiple measurements. In this embodiment, the light-emitting part of the light generator faces the transparent window.

[0095] Embodiment 3

[0096] This embodiment is similar to Embodiment 2, the difference is that in this embodiment, the pump 8 is electrically connected to the control device, and the control device controls the pump 8 to pump the test solution in the liquid storage device 7 into the container 3 or pump the test solution out of the container 3. The pump 8 is a liquid pump provided on the infusion tube 71.

[0097] It is difficult to manually operate the start and stop of the pump 8 to make the liquid level in the container 3 just stay at the position where the light intensity reaches the maximum value. Therefore, the control device can be used to control the operation of the pump 8, and the control device is also connected to the light intensity sensor 5. During the test, as the control device continuously pumps the test solution into the container 3 through the pump 8, the light intensity gradually increases to a maximum value and then gradually decreases. The control device records this maximum value, and then controls the pump 8 to pump the test solution out of the container 3 so that the light intensity reaches the maximum value again.

[0098] Embodiment 4

[0099] This embodiment is similar to Embodiment 2 or 3, the difference is that in this embodiment, a liquid level sensor for detecting the liquid level height of the test solution in the container 3 is provided on the container 3, and the liquid level sensor is electrically connected to the control device.

[0100] The liquid level height of the container 3 is accurately measured by the liquid level sensor, which is convenient for reading, and the measurement accuracy is higher than that of reading the scale provided on the outer side wall of the test tube.

[0101] Embodiment 5

[0102] This embodiment is similar to any one of Embodiments 2 to 4, the difference is that, as Figure 5As shown in the figure, in this embodiment, the adjusting device 9 includes a bracket 91, an annular slide rail 94 provided on the bracket 91, and a slider 95 provided on the annular slide rail 94. The light intensity sensor 5 is provided on the slider 95, and the axis of the annular slide rail 94 is parallel to the container 3.

[0103] The light intensity sensor 5 can move along the slide rail. In this way, the light intensity sensor 5 can move to different sector polarizers 41 to achieve switching between different polarizers. A device for fixing the slider 95 on the annular slide rail 94 can also be provided on the conversion slide rail or the slider 95.

[0104] The polarizer 4 includes a plurality of sector polarizers 41 with different light transmission axis directions provided at one end of the container. The sector polarizers 41 are spliced into a circular polarizer. The polarizer 4 further includes a turntable base for the circular polarizer to rotate around its own axis. A detection window is provided at the photosensitive surface of the turntable base close to the light intensity sensor 5.

[0105] In this embodiment, the light intensity sensor 5 is fixed and the circular polarizer is rotated. In this way, different sector polarizers 41 are rotated to the photosensitive surface of the light intensity sensor 5, and the effect of switching the polarizer can also be achieved. And directly rotating the circular polarizer is more convenient and labor-saving than moving the light intensity sensor 5, and the structure is simpler. A fixing device can also be provided on the turntable base to fix the circular polarizer to prevent the circular polarizer from rotating freely during the test.

[0106] In this embodiment, the polarizer 4 further includes a driving device for driving the circular polarizer to rotate. The driving device is connected to the control device, and the preset sector polarizer 41 can be directly selected through the control device. The control device controls the driving device to start, so that the circular polarizer rotates, thereby switching different sector polarizers 41.

[0107] Embodiment 6

[0108] This embodiment is similar to any one of Embodiments 2 to 5. The difference is that in this embodiment, a piston is provided in the container 3, and a transparent window for light to pass through is provided on the end surface of the piston. The piston changes with the change of the liquid level height of the solution to be measured in the container 3.

[0109] When the liquid supply device adds liquid to the test tube, the piston in the container 3 will be pushed out as the solution is injected. When the liquid supply device withdraws the solution from the test tube, the piston will reset as the solution is withdrawn. Placing a piston in the test tube can not only prevent the liquid surface in the test tube from generating ripples, but also a displacement sensor can be provided on the piston to measure the length of the liquid column in the test tube through the displacement sensor.

[0110] The container 3 is horizontally placed with its own axis parallel to the horizontal direction. The piston in the test tube ensures that the liquid column in the test tube is cylindrical, and the axis of the liquid column is parallel to the propagation direction of the light.

[0111] The container 3 can also be horizontally placed with its own axis parallel to the horizontal direction. At this time, only a piston needs to be arranged in the container 3 so that the test solution in the container 3 forms a cylindrical liquid column, and the moving direction of the piston is consistent with the axis direction of the container 3.

[0112] Obviously, the above-mentioned embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation manners here. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A measuring device for the optical rotation rate of a solution, characterized in that, it includes a container (3) that can accommodate the solution to be measured and allow light to pass through, a light source (1) for generating light, a polarizer (2) for converting the light generated by the light source (1) into polarized light, an analyzer (4) for analyzing the polarized light, a light intensity sensor (5) for measuring the light intensity, a control device electrically connected to the light intensity sensor (5), and a filter (6). The light incident surface and the light exit surface of the container (3) are both light-transmitting surfaces. The light generated by the light source (1) sequentially passes through the polarizer (2), the container (3), and the analyzer (4) and finally enters the light intensity sensor (5). The propagation direction of the light is parallel to the axis of the container (3). A filter for filtering the light into a specific wavelength is also provided between the light source (1) and the light intensity sensor (5); It further includes an adjusting device (9) for adjusting the position of the light intensity sensor (5). The analyzer (4) includes a plurality of sector-shaped analyzer pieces (41) with different light-transmitting axis directions provided at one end of the container. The sector-shaped analyzer pieces (41) are spliced into a circular analyzer. The adjusting device (9) adjusts the position of the light intensity sensor (5) to align the photosensitive surface of the light intensity sensor (5) with different sector-shaped analyzer pieces (41); It further includes a liquid reservoir (7) for storing the solution to be measured and a pump (8). The liquid reservoir (7) is connected to the container (3). The pump (8) can pump the solution to be measured in the liquid reservoir (7) into the container (3) or extract it from the container (3).

2. The measuring device for the optical rotation rate of a solution according to claim 1, characterized in that, the adjusting device (9) includes a bracket (91), a cross clamp (92) provided on the bracket (91), and a fixing clamp (93) for clamping the light intensity sensor (5). One end of the cross clamp (92) is clamped on the bracket (91), and the other end clamps the fixing clamp (93). The light intensity sensor (5) is clamped and fixed by the fixing clamp (93).

3. The measuring device for the optical rotation rate of a solution according to claim 1 or 2, characterized in that, a liquid inlet (31) is provided at the bottom of the container (3), an outlet is provided at the bottom of the liquid reservoir (7), a liquid delivery pipe (71) is provided between the liquid inlet (31) and the outlet, an air inlet is provided at the top of the liquid reservoir (7), the pump (8) is an air inflation pump, and the air nozzle of the air inflation pump is detachably connected to the air inlet.

4. The measuring device for the optical rotation rate of a solution according to claim 3, characterized in that, the container (3) is a cylinder, the light incident surface and the light exit surface of the container (3) are the two end faces of the container (3), the side wall of the container (3) is made of a transparent material, and a scale for displaying the liquid level height is provided on the outer side wall of the container (3).

5. A measuring method applied to the measuring device for the optical rotation rate of a solution according to any one of claims 1-4, characterized in that, it includes the following steps: S1: The light source (1) emits light rays. The light rays first pass through the polarizer (2) and then enter the container (3) filled with the solution to be measured. Both the incident surface and the exit surface of the container (3) are light-transmitting surfaces. After the light rays exit from the container (3), they pass through the analyzer (4), and finally the light rays enter the light intensity sensor (5) connected to the control device. Moreover, a filter (6) for the light rays to pass through is provided between the light source (1) and the light intensity sensor (5), and the angle between the transmission axis of the analyzer plate in the analyzer (4) and the transmission axis of the polarizer plate in the polarizer (2) is recorded. ; S2: Inject the test solution with a concentration of C into the container (3). As the liquid column length in the container (3) gradually increases, the light intensity sensor (5) recognizes that the light intensity gradually changes and is displayed in the control device. Then, adjust the liquid column length in the container (3) to the maximum value of the light intensity displayed by the control device, and record the liquid column length in the container (3) at this time, which is the optical path. ; S3: Calculate the optical rotation rate of the solution to be measured using the formula ; S4: Repeat steps S1 to S3; or use different analyzers to change the angle between the transmission axes of the analyzer and the polarizer; or use different filters to change the wavelength, and then repeat steps S1 to S3 to conduct multiple experiments. Take multiple measurements by repeating steps S1 to S3, changing the angle between the polarizer and analyzer, or changing the wavelength by using different filters.

6. The measurement method according to claim 5, wherein, before step S1, the following steps are further included: S0: Configure a test solution with a concentration of C, rinse the container (3) with the test solution, and select an analyzer with different light transmission axes according to the solution concentration.

7. The measurement method according to claim 5, wherein, in step S2, slowly inject the test solution from the bottom of the container (3), and the light intensity sensor (5) is based on the reading when the liquid level of the test solution is calm.

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