A solution concentration servo detection device and method

Abstract

The application belongs to the technical field of photoelectric detection, and relates to a solution concentration servo detection device and method. The device comprises a light source, a scanning galvanometer, a trapezoidal prism and a linear array CCD. The scanning galvanometer is provided with a rotating part, so that the mirror surface of the scanning galvanometer can be axially rotated horizontally. The light emitted by the light source is directed to the mirror surface. The trapezoidal prism is horizontally arranged below the scanning galvanometer. Among two horizontal surfaces of the trapezoidal prism, one surface of the long side is a top surface close to the scanning galvanometer, and one surface of the short side is a bottom surface. The light is reflected by the mirror surface, passes through the top surface and reaches a first reflecting surface of the trapezoidal prism. The linear array CCD is arranged above the trapezoidal prism, and the light is reflected by a second reflecting surface of the trapezoidal prism and projected on an image surface of the linear array CCD. The application reduces the use of precision optical instruments, reduces the installation and calibration requirements of the equipment, and improves the production efficiency of the equipment.

Description

Technical Field

[0001] This application belongs to the field of photoelectric detection technology, specifically relating to a solution concentration servo detection device and method. Background Technology

[0002] Refractive index is an important parameter reflecting the properties of optical media (transparent and translucent materials). In industrial production, the concentration of a solution is usually determined by measuring its refractive index. Traditional refractive index measurement equipment includes V-prism refractometers and Abbe refractometers. Although these optical instruments are highly accurate, they are significantly affected by human factors. Therefore, automated refractometers based on linear CCD arrays are now frequently used. However, to achieve refractive index measurement within the specified range, automated refractometers based on linear CCD arrays use condenser lenses and imaging lenses, which requires high system assembly precision. This necessitates individual calibration of each piece of equipment during production, thus impacting production efficiency. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art or related technologies, namely, the problem of high assembly accuracy requirements and low production efficiency of automatic refractometer systems based on linear CCD arrays.

[0004] In view of this, a first aspect of the present invention provides a solution concentration servo detection device, which is based on the refractive method, eliminates the condenser lens and imaging lens, and realizes the measurement of the refractive index of the solution by using collimated light scanning and software compensation for the deflection angle.

[0005] A second aspect of the present invention provides a solution concentration servo detection method, wherein the solution concentration is detected using the above-described solution concentration servo detection device.

[0006] Specifically, the following technical solutions are included: According to a first aspect of the embodiments of this application, a solution concentration servo detection device is provided, including a light source, a scanning galvanometer, a trapezoidal prism, and a linear CCD array; the scanning galvanometer is configured via a rotating component, allowing the mirror surface of the scanning galvanometer to rotate axially with the horizontal direction as an axis; the light emitted from the light source is directed toward the mirror surface; the trapezoidal prism is horizontally disposed below the scanning galvanometer; of the two horizontal surfaces of the trapezoidal prism, the longer side is the top surface near the scanning galvanometer, and the shorter side is the bottom surface; the light is reflected by the mirror surface, passes through the top surface, and reaches the first reflecting surface of the trapezoidal prism; the linear CCD array is disposed above the trapezoidal prism, and the light is reflected by the second reflecting surface of the trapezoidal prism and projected onto the image plane of the linear CCD array.

[0007] Furthermore, the projection path of the light is as follows: the light source, the mirror, the top surface, the first reflecting surface, the bottom surface, the second reflecting surface, the top surface, and the linear CCD array.

[0008] Preferably, the light source includes a semiconductor laser module.

[0009] Preferably, the rotating component includes a rotating shaft connected to one end of the scanning galvanometer, and the rotating shaft is horizontally positioned.

[0010] Furthermore, it also includes a sealing body; the light source, the scanning galvanometer, and the linear CCD are all fixedly disposed within the sealing body; the portion of the trapezoidal prism, except for the bottom surface, is disposed within the sealing body.

[0011] The second aspect of this invention provides a solution concentration servo detection method. This method uses a solution concentration servo detection device as described in any of the above technical solutions to detect the solution concentration. The method includes: contacting the bottom surface of the solution to be tested with the bottom surface; adjusting the scanning galvanometer to position the mirror at an initial position; turning on the light source and recording the initial light intensity of the bright area of ​​the linear CCD image plane; adjusting the scanning galvanometer to deflect the mirror from the initial position by a fixed angle Δα; recording the deflected light intensity of the bright area of ​​the linear CCD image plane; calculating the light intensity difference Δβ between the initial light intensity and the deflected light intensity; and calculating the concentration of the solution to be tested based on Δβ.

[0012] Furthermore, the initial position is a position where the light reflected from the mirror is perpendicular to the top surface.

[0013] Furthermore, the step of calculating the concentration of the test solution based on Δβ includes: determining the critical angle of the test solution based on Δβ; calculating the refractive index of the test solution based on the critical angle; and determining the concentration of the test solution based on the refractive index.

[0014] Furthermore, before determining the critical angle of the solution to be tested based on Δβ, the method further includes: creating a relationship curve between Δβ and the critical angle of the solution with a fixed deflection angle Δα.

[0015] Furthermore, before determining the concentration of the solution to be tested based on the refractive index, the method further includes: creating a curve showing the relationship between the refractive index and the concentration of the solution.

[0016] Compared with the prior art, the present invention has at least the following beneficial effects: The apparatus and method of this application, without using additional condenser lenses and imaging lenses, utilizes a driving scanning galvanometer to deflect incident light at different angles, thus achieving changes in light intensity on the image plane of a linear CCD. Based on these changes in light intensity on the CCD image plane, the critical angle for total internal reflection of the test solution is calculated, thereby determining the refractive index of the solution and enabling the detection of its concentration. This application reduces the use of precision optical instruments, lowers equipment installation and calibration requirements, improves equipment production efficiency, and provides a novel detection method for refractive index solution concentration detection. Attached Figure Description

[0017] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. In the drawings: Figure 1 This is a schematic diagram of the internal structure of the sealing body in an embodiment of this application; Figure 2 This is a schematic diagram of the optical path at the initial position in an embodiment of this application; Figure 3 This is a schematic diagram of the optical path for the deflection position in an embodiment of this application; Figure 4 This is a flowchart of the detection method in an embodiment of this application.

[0018] The attached figures are labeled as follows: 1-Light source; 2-Scanning galvanometer; 21-Mirror surface; 3-Trapezoidal prism; 31-Top surface; 32-Bottom surface; 33-First reflecting surface; 34-Second reflecting surface; 4-Linear CCD; 5-Rotation axis. Detailed Implementation

[0019] To better understand the above technical solutions, the technical solutions of the embodiments of this application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of this application and the specific features in the embodiments are detailed descriptions of the technical solutions of the embodiments of this application, rather than limitations on the technical solutions of this application. In the absence of conflict, the embodiments of this application and the technical features in the embodiments can be combined with each other.

[0020] In view of this, according to a first aspect of the embodiments of this application, a solution concentration servo detection device is provided, such as... Figure 1As shown, the system includes a light source 1, a scanning galvanometer 2, a trapezoidal prism 3, and a linear CCD 4. The scanning galvanometer 2 is configured via a rotating component, allowing its mirror surface 21 to rotate axially around a horizontal axis. The light emitted from the light source 1 is directed towards the mirror surface 21. The trapezoidal prism 3 is horizontally positioned below the scanning galvanometer 2. Of the two horizontal surfaces of the trapezoidal prism 3, the longer side is the top surface 31 closest to the scanning galvanometer 2, and the shorter side is the bottom surface 32. The light rays are reflected by the mirror surface 21, pass through the top surface 31, and reach the first reflecting surface 33 of the trapezoidal prism 3. The linear CCD 4 is positioned above the trapezoidal prism 3, and the light rays are reflected by the second reflecting surface 34 of the trapezoidal prism 3 and projected onto the image surface of the linear CCD 4.

[0021] Furthermore, in one embodiment, such as Figure 2 , Figure 3 As shown, the projection path of the light is as follows: the light source 1, the mirror 21, the top surface 31, the first reflecting surface 33, the bottom surface 32, the second reflecting surface 34, the top surface 31 and the linear CCD 4.

[0022] Specifically, the bottom surface 32 is used to contact the surface of the solution to be tested. The projection path of the light is as follows: emitted from the light source 1, reflected by the mirror 21 to the top surface 31, refracted, reaching the first reflecting surface 33, and then reflected back to the bottom surface 32. At this time, a portion of the light is reflected by the bottom surface 32 to the second reflecting surface 34, and after further reflection and refraction by the top surface 31, it is finally projected onto the image plane of the linear CCD 4; the other portion of the light is refracted into the solution to be tested. Different angles at which the light incident on the bottom surface 32 will result in different amounts of light refracted into the solution to be tested, thus causing changes in the light intensity projected onto the image plane of the linear CCD 4.

[0023] Preferably, in a specific embodiment, the light source 1 includes a semiconductor laser module. Specifically, the semiconductor laser module emits parallel light rays towards the mirror 21 through its built-in collimating lens.

[0024] Preferably, in a specific embodiment, the rotating component includes a rotating shaft 5 connected to one end of the scanning galvanometer 2, and the rotating shaft 5 is horizontally arranged.

[0025] Specifically, in actual working conditions, the light source 1 is set horizontally, the light emitted by the light source 1 is also horizontal light, and the rotating shaft 5 is perpendicular to the light.

[0026] Furthermore, in one embodiment, a sealing body is also included; the light source 1, the scanning galvanometer 2, and the linear CCD 4 are all fixedly disposed within the sealing body; the trapezoidal prism 3, except for the bottom surface 32, is disposed within the sealing body.

[0027] Specifically, the light source 1, the scanning galvanometer 2, the trapezoidal prism 3, and the linear CCD 4 are all fixedly mounted on the inner wall of the sealed body, and the bottom surface 32 is exposed outside the sealed body so that the bottom surface 32 can fully contact the liquid surface of the solution to be tested during detection.

[0028] According to a second aspect of the embodiments of this application, a solution concentration servo detection method is provided, wherein the method uses a solution concentration servo detection device as described in any of the above technical solutions to detect the solution concentration, such as... Figure 4 As shown, the method includes: bringing the bottom surface 32 into contact with the surface of the solution to be tested; adjusting the scanning galvanometer 2 so that the mirror surface 21 is in the initial position; turning on the light source 1 and recording the initial light intensity of the bright area of ​​the linear CCD 4 image plane; adjusting the scanning galvanometer 2 so that the mirror surface 21 is deflected by a fixed angle Δα from the initial position; recording the deflected light intensity of the bright area of ​​the linear CCD 4 image plane; calculating the light intensity difference Δβ between the initial light intensity and the deflected light intensity; and calculating the concentration of the solution to be tested based on Δβ.

[0029] Furthermore, in one embodiment, the initial position is a position where the light reflected by the mirror 21 is perpendicular to the top surface 31.

[0030] Specifically, in actual working conditions, both the light source 1 and the scanning mirror 2 are horizontally positioned. Therefore, the initial position is when the angle between the mirror surface 21 and the horizontal plane is 45°. When the mirror surface 21 is in the initial position, the projection path of the light is as follows: Figure 2 As shown; when the mirror 21 deflects by Δα, the projection path of the light is as follows. Figure 3 As shown.

[0031] Furthermore, in one embodiment, such as Figure 4 As shown, the step of calculating the concentration of the test solution based on Δβ includes: determining the critical angle of the test solution based on Δβ; calculating the refractive index of the test solution based on the critical angle; and determining the concentration of the test solution based on the refractive index.

[0032] Furthermore, in one embodiment, such as Figure 4 As shown, before determining the critical angle of the solution to be tested based on Δβ, the method further includes: creating a relationship curve between Δβ and the critical angle of the solution with a fixed deflection angle Δα.

[0033] Specifically, with a fixed deflection angle Δα, a Δβ-critical angle relationship curve can be created based on the height of the scanning galvanometer 2 from the trapezoidal prism 3, the air refractive index, the material refractive index of the trapezoidal prism 3, and the composition of the dissolved substances in the solution. When determining the specific value of Δβ during detection, the critical angle of the solution to be tested can be determined through the preset Δβ-critical angle relationship curve.

[0034] Furthermore, in one embodiment, such as Figure 4 As shown, before determining the concentration of the solution to be tested based on the refractive index, the method further includes: creating a curve showing the relationship between the refractive index and the concentration of the solution.

[0035] Specifically, based on Snell's law, the refractive index of the solution uniquely determines the critical angle at which total internal reflection occurs at the prism-solution interface. Therefore, after determining the critical angle of the solution to be tested, the refractive index of the solution to be tested can be calculated.

[0036] Simultaneously, changes in solution concentration directly lead to a proportional change in the number of photoactive particles (molecules or ions) per unit volume, thus affecting the overall optical density of the solution. Therefore, the refractive index of a solution has a direct, usually linear or approximately linear, relationship with its concentration (at a specific temperature). Generally, the higher the concentration, the greater the refractive index. A typical application is sucrose solution, where, within the common concentration range of 0-30%, the refractive index is highly linearly positively correlated with concentration. Therefore, based on the different compositions of dissolved substances in the solution, a refractive index-concentration relationship curve can be created. Once the refractive index of the solution to be tested is determined, its concentration value can be determined using a preset refractive index-concentration relationship curve.

[0037] This method possesses all the beneficial effects of the device described above, which will not be elaborated upon here.

[0038] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0039] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A solution concentration servo detection device, characterized in that, It includes a light source (1), a scanning galvanometer (2), a trapezoidal prism (3), and a linear CCD array (4); The scanning galvanometer (2) is configured by a rotating component, so that the mirror surface (21) of the scanning galvanometer (2) can rotate axially with the horizontal direction as the axis; The light emitted by the light source (1) is directed toward the mirror (21). The trapezoidal prism (3) is horizontally positioned below the scanning galvanometer (2); Of the two horizontal planes of the trapezoidal prism (3), the side with the longer side is the top surface (31) close to the scanning galvanometer (2), and the side with the shorter side is the bottom surface (32). The light is reflected by the mirror (21), passes through the top surface (31), and reaches the first reflecting surface (33) of the trapezoidal prism (3). The linear CCD (4) is positioned above the trapezoidal prism (3), and the light rays are reflected by the second reflecting surface (34) of the trapezoidal prism (3) and projected onto the image plane of the linear CCD (4).

2. The solution concentration servo detection device according to claim 1, characterized in that, The projection path of the light is as follows: the light source (1), the mirror (21), the top surface (31), the first reflective surface (33), the bottom surface (32), the second reflective surface (34), the top surface (31) and the linear CCD (4).

3. The solution concentration servo detection device according to claim 1, characterized in that, The light source (1) includes a semiconductor laser module.

4. The solution concentration servo detection device according to claim 1, characterized in that, The rotating component includes a rotating shaft (5) connected to one end of the scanning galvanometer (2), and the rotating shaft (5) is horizontally arranged.

5. The solution concentration servo detection device according to claim 1, characterized in that, It also includes a sealing body; The light source (1), the scanning galvanometer (2), and the linear CCD (4) are all fixedly disposed within the sealed body; The trapezoidal prism (3), except for the bottom surface (32), is disposed within the sealed body.

6. A servo detection method for solution concentration, characterized in that, The method of detecting solution concentration using the solution concentration servo detection device as described in any one of claims 1 to 5 includes: Make the bottom surface (32) contact the surface of the solution to be tested; Adjust the scanning galvanometer (2) so that the mirror surface (21) is in the initial position; Turn on the light source (1) and record the initial light intensity of the bright area of ​​the image plane of the linear CCD (4); Adjust the scanning galvanometer (2) so that the mirror surface (21) is deflected by a fixed angle Δα from the initial position; Record the deflection light intensity of the bright area of ​​the image plane of the linear CCD (4); Calculate the light intensity difference Δβ between the initial light intensity and the deflected light intensity; The concentration of the test solution is calculated based on Δβ.

7. The solution concentration servo detection method according to claim 6, characterized in that, The initial position is the position where the light reflected by the mirror (21) is perpendicular to the top surface (31).

8. The solution concentration servo detection method according to claim 6, characterized in that, The step of calculating the concentration of the test solution based on Δβ includes: The critical angle of the solution to be tested is determined based on Δβ; Calculate the refractive index of the solution to be tested based on the critical angle; The concentration of the solution to be tested is determined based on the refractive index.

9. The solution concentration servo detection method according to claim 8, characterized in that, Before determining the critical angle of the solution to be tested based on Δβ, the method further includes: creating a curve relating Δβ to the critical angle of the solution with a fixed deflection angle Δα.

10. The solution concentration servo detection method according to claim 8, characterized in that, Before determining the concentration of the solution to be tested based on the refractive index, the method further includes: creating a curve showing the relationship between the refractive index and the concentration of the solution.

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