WO2023024523A1

WO2023024523A1 - Refractometer, detection apparatus, and method for detecting refractive index

Info

Publication number: WO2023024523A1
Application number: PCT/CN2022/085257
Authority: WO
Inventors: 彭倜; 徐凌杰; 吴泳智
Original assignee: 深圳市流数科技有限公司
Priority date: 2021-08-25
Filing date: 2022-04-06
Publication date: 2023-03-02
Also published as: WO2023023964A1

Abstract

A refractometer, comprising a light source module (1), a reflection module (2), a convergence module (3), a photosensitive surface array (4), a control module, and a processor. The control module is used to control the light source module (1) to emit a light beam. The reflection module (2) is used to receive the light beam from the light source module (1), and when the light beam from the light source module (1) meets a total reflection condition in the reflection module (2), the light beam is totally reflected in the reflection module (2) and enters the convergence module (3). The convergence module (3) is used to converge the light beam from the reflection module (2) to a focal plane of the convergence module (3). The photosensitive surface array (4) is located on the focal plane of the convergence module (3), and the control module is further used to control the photosensitive surface array (4) to detect the received light beam and output a detected image. The processor is used to determine, according to the detected image, a brightness mutation boundary in the detected image and determine, according to the position of the brightness mutation boundary, a refractive index corresponding to the brightness mutation boundary.

Description

A kind of refractometer, detecting device and method for detecting refraction index

technical field

The invention belongs to the field of liquid refractive index measurement, and in particular relates to a refractometer, a detection device and a method for detecting the refractive index.

Background technique

A refractometer is a device that measures the refractive index of liquids. Since the solid soluble matter in the liquid will increase the refractive index of the liquid after dissolving, the measurement of the solid soluble matter content in the liquid can be realized through the measurement of the refractive index, so the refractometer can be used to measure the content of the solid soluble matter in the liquid . The solid soluble matter in the aqueous solution is usually sugar, so the refractometer is also called a sugar meter when measuring beverages (such as fruit juice, coffee, etc.).

Fig. 1 is a structural schematic diagram of an existing refractometer. The refractometer includes a slit 1', an LED light source 2', a one-dimensional sensitive line array 3', a triangular prism 4' and a processor (not shown). The principle of the refractometer utilizes the fact that the total reflection angle is determined by the refractive index of the two materials at the interface. When the refractometer is placed in the liquid to be measured, if the refractive index of the liquid to be measured is lower than that of the triangular prism 4′, according to the law of refraction sin (α _{refraction angle} )*n _{liquid to be measured} =sin (α _{incident angle} )* It can be seen from the n _{triangular prism} that the incident angle of the light beam on the side 5 ' that is in contact with the liquid in the triangular prism 4 ' satisfies

total reflection occurs. That is to say, when the LED light source 2' is a point light source, in the light beam incident on the surface 5', the part where the incident angle is greater than the total reflection angle undergoes total reflection, and when the incident angle is smaller than the total reflection angle, transmission and reflection coexist. And the brightness of reflection is smaller than that of total reflection. Therefore, in the one-dimensional image formed by the one-dimensional photosensitive line array 3', the pixels at different positions on the image correspond to the light beams incident on the surface 5' from the point light source at different angles, corresponding to the light beams incident on the surface 5' at the angle of total reflection. A distinct brightness discontinuity can be seen near the pixels of the beam to facet 5'. The processor can measure the total reflection angle through this sudden change in brightness, and calculate the refractive index of the liquid to be measured accordingly.

However, due to the limited area of the light-emitting surface of the LED light source due to the process, the light beams of the LED light source 2' incident on the surface 5' at different incident angles may be reflected to the same point on the sensitive line array 3', resulting in indistinguishable The angle at which these lights emerge makes it difficult to determine the angle of total reflection. Therefore, the existing refractometer is provided with a slit 1' on the outgoing light path of the LED light source 2', so that the light source is a very small point light source in the direction parallel to the sensitive line array 3' to define the impact on the sensitive line array 3. 'The angle of each beam on . The essence of the slit 1' is to decouple the position and direction of the light, so that the refractometer only needs to detect the direction of the light without being disturbed by the position of the light. However, this design will result in a very large size of the sensitive line array 3 ′, especially in the case where the measurement range of the refractive index is required to be relatively large. The specific reasons are as follows.

As shown in Figure 2, the size of the sensitive line array 3' is 2*tan(α/2)*d, d represents the optical path distance from the LED light source 2' to the sensitive line array 3', and α is the LED light source 2 'The overall opening angle of the outgoing light. In the case where the measurement range of the refractive index is required to be relatively large (for example, to measure liquids with different refractive indices), α needs to have a larger value, so the size of the sensitive line array 3 ′ also needs to be increased accordingly. This is not conducive to miniaturization of the refractometer.

For semiconductor chips such as CCD or CMOS, the larger the physical size, the higher the cost. Considering the limited semiconductor wafer size, the increase in device size will lead to a decrease in shipment rate and yield rate. Large-size chips also mean that the difficulty of packaging and placement increases, and the warping rate of the placement increases, which will lead to an increase in cost. Usually, because of such a large semiconductor size requirement, only a linear array (one-dimensional array) can meet the cost requirements. However, the installation position and accuracy requirements of the line array perpendicular to its own direction are very high. When the optical path deviates (caused by thermal expansion and contraction, impact or mechanical deformation, etc.), it cannot be automatically corrected, and it is easily affected by ambient light or stray light. lead to measurement deviation.

Contents of the invention

The object of the present invention is to provide a refractometer with low cost, small volume, large measurement range and good robustness, a smart cup with the refractometer and a method for detecting the refractive index to solve the above problems. In order to achieve the above object, the technical solution adopted in the present invention is: a refractometer, including a light source module, a reflection module, a converging module, a photosensitive area array, a control module and a processor; the control module is used to control the output of the light source module light beam; the reflection module is used to receive the light beam from the light source module, when the light beam from the light source module satisfies the total reflection condition in the reflection module, the light beam is totally reflected in the reflection module, and incident to the converging module; the converging module is used to converge the light beam from the reflecting module onto the focal plane of the converging module; the photosensitive surface array is located on the focal plane of the converging module, the The control module is also used to control the photosensitive surface array to detect the received light beam and output a detection image; the processor is used to determine the boundary line of the sudden change in brightness in the detection image according to the detection image, and to The position of the boundary line determines the refractive index corresponding to the boundary line of the abrupt change in brightness.

The present invention also provides a detection device, including the above-mentioned refractometer.

The present invention also provides a method for detecting the refractive index, comprising: sending a light beam to the reflection module in the refractometer; converging the light beam at least totally reflected by the reflection module to the focal plane located in the convergence module through the convergence module The photosensitive array on the photosensitive array; use the photosensitive array to image the received light beam to generate a detection image; determine the brightness mutation boundary line in the detection image according to the detection image; according to the position of the brightness mutation boundary line in the detection image Determine the refractive index of the medium corresponding to the sudden change in brightness.

The refractometer of the present invention arranges the photosensitive surface array on the focal plane of the image side of the lens module, and the lens module adopts the infinity focus imaging method, so that a non-point light source can be used as the light source, so that the photosensitive surface array can be shared by the size of the light source. The size of the photosensitive area makes the size of the photosensitive area very small, which has the advantages of low cost, small size, large measurement range, and good robustness; moreover, the refractometer uses an area array CMOS detection image sensor, which has lower cost and higher accuracy High, reducing installation requirements, and can achieve many things that one-dimensional sensors cannot do, such as improving accuracy, improving anti-interference ability, adding other measurement functions, etc.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For Those of ordinary skill in the art can also obtain other drawings based on these drawings without making creative efforts.

Fig. 1 is a structural schematic diagram of an existing refractometer; Fig. 2 is a schematic diagram of the side where the sensitive line array is equivalent to the liquid surface in Fig. 1; Fig. 3 is a schematic cross-sectional view of a structure of a refractometer; Fig. 4 is a schematic diagram of the imaging principle of the lens unit using infinity focusing; FIG. 5 is a schematic diagram of an equivalent optical system of a refractometer; FIG. 6 and FIG. 7 are respectively the structure of the refractometer using light source modules and lens modules of different sizes in this application Schematic diagram; Fig. 8 is a detection image of the light beam received by the photosensitive surface array when the refractometer detects a liquid to be measured; Fig. 9 is a structural schematic diagram of an example of a refractometer; Fig. Figure 11 and Figure 12 are schematic diagrams of two examples of detection images respectively; Figure 13 is an example of the top view of the refractometer shown in Figure 9; Figure 14 It is a schematic diagram of the positional relationship between the prism, the coating on the surface of the prism, the waterproof part and the liquid to be tested; Figure 15-17 is a schematic diagram of the detection image; the left side of Figure 18 is the detection image formed by the light beam received by the photosensitive surface array Figure 19 is a schematic structural diagram of a smart cup; Figure 20 is a structural schematic diagram of a smart scale; Figure 21 is a method for detecting the refractive index of a liquid to be measured using a refractometer in this application A schematic diagram of an embodiment.

Detailed ways

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numerals in different drawings refer to the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatuses and methods consistent with aspects of the invention as recited in the appended claims.

The terms used in the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. As used herein and in the appended claims, the singular forms "a", "the", and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. It should also be understood that the term "and/or" as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

It should be understood that although the terms first, second, third, etc. may be used in the present invention to describe various information, the information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another.

An exemplary structure of the refractometer in this application is described below. In this example, compared to the prior art where a small hole is set at the light source exit end to achieve decoupling of the angle and position of the incident light beam of the sensitive line array in one dimension (that is, the direction parallel to the sensitive line array), In this embodiment, the converging module located on the beam incident side of the photosensitive module is used to decouple the angle and position of the incident beam of the photosensitive module, and the converging module can realize decoupling in two dimensions, so the photosensitive module can use The photosensitive area array detects the light beam, and then the refractive index detection optical path for self-calibration and the refractive index detection optical path of the liquid to be measured can share the light source and the photosensitive area array, avoiding the offset between the two sets of detection optical paths (such as semiconductor chips The calculation deviation caused by poor consistency, poor consistency of installation structure, installation deviation, mechanical shock or temperature drift, etc.)

In addition, by adding a converging module in front of the photosensitive array and using infinity focusing to decouple the position and direction of the light, the light emitted from the reflective module at one exit angle can be converged to the at the same location as the sensor. In the prior art, since the divergence angle of the light source module is required to be relatively large, but the divergence angle of the LED light source itself is not very large, it is necessary to find a specially-made LED light source with a large angle and a small light-emitting surface in the solution of the prior art. Compared with the prior art, the light source module in this application does not need to bear the function of distinguishing angles and positions, and there are less restrictions on the selection of light emitting units in the light source module.

Moreover, compared with the prior art, because the setting of small holes needs to use a linear array for detection, in this embodiment, an area array is used to detect the light beam, which can obtain more information than the linear array, which is beneficial to improve the detection of the liquid to be tested. The accuracy of the refractive index can even obtain more information about the liquid to be measured. Moreover, the refractometer uses an area array CMOS detection image sensor, which has lower cost, higher accuracy, lower installation requirements, and can achieve many things that one-dimensional sensors cannot do, such as improving accuracy, improving anti-interference ability, increasing Other measurement functions, etc. Moreover, compared with the refractometers of the prior art, the reflection properties of the total reflection surface interface must be kept consistent within the range of the liquid level. Since the light direction can be directly measured in the present application, even if there are bubbles or the liquid to be measured at the detection surface of the prism In the case that the total reflection interface is not completely covered, the boundaries of sudden changes in brightness are still clearly distinguishable.

Since the refractive index of the liquid will drift with the temperature, there will be a deviation when determining the solid soluble content of the liquid based on the refractive index of the liquid. In order to ensure the measurement accuracy of the refractometer, an existing solution is to calibrate the sudden change in brightness corresponding to a liquid with a fixed concentration (such as 0Brix liquid) in the image formed by the sensitive line array of the refractometer, so as to ensure the refraction The measurement accuracy of the instrument. Specifically, the position of the abrupt change in the 0Brix brightness is preset in the refractometer. The refractometer measures clear water in real time, forming a sudden change in brightness on the imaging of the sensitive line array as a self-calibration position, and then when the refractometer measures the refractive index of the liquid to be tested and the content of solid solubles, it is based on the sudden change in brightness of 0Brix and The self-calibration position corrects the real-time measurement results; but this requires self-calibration with clean water before measurement. If you want to achieve simultaneous calibration of measurement, if you use the existing calculation scheme, because you need to form a self-calibration position, you need to set up two emitting light sources and corresponding two sensitive line arrays, and one emitting light source and corresponding sensitive line arrays are used for detection. The liquid used for self-calibration, another emitting light source and a sensitive line array are used to detect the liquid to be tested. However, during the use of the refractometer, the detection of the liquid for self-calibration and the detection of the liquid to be measured are two different structures, and it is prone to inaccurate self-calibration results caused by the offset of the two sets of optical paths in the refractometer. calculation deviation.

The refractometer in this embodiment can also be used as an object for self-calibration by fixing a second medium in the reflection module instead of clear water in the prior art, and the light beam can be completely reflected on the photosensitive surface array before it is incident on the second medium. The boundary line of sudden change in brightness is formed on the image to measure the refractive index of the second medium, and the measurement result of the second medium is used to correct the measurement result of the liquid to be tested. Compared with the existing technology, since the combination of the converging module and the photosensitive array is used to decouple the position and direction of the light beam, and the photosensitive array is two-dimensional, the same receiver can be used for the measurement of the second medium and the liquid to be measured To detect, and even use the same emitting light source to form the boundary line of the sudden change in brightness corresponding to the second medium and the liquid to be measured on the photosensitive surface array, which can avoid the measurement error caused by the difference between different sensitive line arrays and light paths in the prior art, Improve the accuracy of the measurement results of the refractometer. Moreover, due to the introduction of the second medium to calibrate the refractive index of the liquid to be measured, compared with the refractometer in the prior art, the refractometer in this embodiment can eliminate the process of water calibration, and can more accurately measure high-temperature liquids. Wider application scenarios.

The embodiment shown in FIG. 3 will be described in detail below. FIG. 3 is a schematic cross-sectional view of a structure of a refractometer. As shown in FIG. 3 , the refractometer includes a light source module 1 , a reflection module 2 , a converging module 3 , a photosensitive array 4 , a control module (not shown in the figure) and a processor (not shown in the figure). Wherein, the control module is used for controlling the light beam emitted by the light source module 1 and for controlling the photosensitive surface array 4 to perform light detection. Optionally, the control module includes a light source controller and a photosensitive controller for controlling the light source module 1 and the photosensitive array 4 respectively. The reflection module 2 is used for receiving the light beam from the light source module 1 . After the light beam from the light source module 1 enters the reflection module 2, when the total reflection condition is satisfied, the light beam with an incident angle greater than or equal to the total reflection angle undergoes total reflection, and the light beam with an incident angle smaller than the total reflection angle undergoes partial transmission and partial reflection at this point. Reflected, reflected and totally reflected light beams exit the reflection module 2 and then enter the converging module 3 . The converging module 3 is used for converging the light beams from the reflecting module 2 to the photosensitive surface array 4 located on the focal plane of the converging module 3 . The control module is also used to control the photosensitive surface array 4 to detect the received light beam and output a detection image.

The converging module 3 can be a lens, and the focal plane of the converging module 3 refers to the focal plane of the lens; or a lens group composed of at least two lenses, and the focal plane of the converging module 3 is the equivalent of the lens group effective focal plane. In the solution of using the lens group, the aberration and distortion of the imaging of the converging module can also be reduced through the optical design of the lens.

The function of the convergence module will be explained below with reference to FIG. 4 by taking the convergence module as a lens as an example. As shown in Figure 4, ideally parallel light can be converged by a lens to a converging point on the focal plane. The converging point extends from the optical center of the lens to the point of intersection with the focal plane in the direction of the parallel light. Therefore, the converging point is only related to the direction of the light, not to the exit position of the light. Using this principle, this embodiment can decouple the position and direction of the light by setting the converging module in front of the photosensitive array, so that in any plane passing through the optical center of the converging module, the plane is reflected at the same exit angle The light totally reflected at different positions of the module will be converged to the same position of the photosensitive surface array 4 , and finally a boundary line of abrupt change in brightness corresponding to the total reflection angle is formed on the photosensitive surface array 4 . Due to the setting of the converging module, different positions of the sudden brightness boundary in the detection image correspond to beams that are totally reflected at different total reflection angles, so the processor can determine the total reflection angle corresponding to the sudden brightness boundary by obtaining the position of the sudden brightness boundary , and then calculate the corresponding refractive index according to the total reflection angle.

In one example, the light source module 1 includes an LED light bar, or includes a light source composed of a plurality of LED light beads by patching or packaging. The wavelength of the LED needs to be compatible with the wavelength response of the CMOS photosensitive array. The wavelength can be between 300nm and 1000nm, for example, the wavelength can be between 400nm and 500nm, or between 500nm and 600nm, or between 600nm and 700nm. Either between 700nm and 800nm, or between 800nnm and 900nm. Optionally, the wavelength of the LED is in the green light band, for example, the central wavelength is between 500nm and 600nm. Since a common photosensitive area array on the market is a CMOS sensor with a Bayer pattern of RGGB, this type of photosensitive area array has a higher resolution and is more sensitive to the G channel. Using the green light band can better communicate with the photosensitive surface. array with.

In one example, as shown in FIG. 3 , an optical filter 7 matching the outgoing light of the light source module 1 is provided on the optical path between the detection surface of the reflective module 2 and the photosensitive array 4 for transmitting the outgoing light of the light source module 1 . In order to reduce the interference of background light on the detection results, the incident light and reflected light beams of other wavelength bands can be reduced. Optionally, the output light of the light source module 1 is of a single wavelength, so that it is easier to match a narrow-band filter to eliminate background light.

In one example, the reflective module 2 includes a first medium 21 . The refractometer also includes a detection area arranged on the surface of the first medium, used for supporting the liquid 5 to be measured when the refractometer detects the liquid 5 to be measured. When the detection area is covered with the liquid to be tested and the refractive index of the liquid to be tested is lower than that of the first medium, at least part of the light beam is totally reflected by the liquid to be tested. The processor can calculate the refractive index of the liquid to be tested according to the position of the totally reflected light beam corresponding to the boundary line of the sudden change in brightness in the detection image.

The first medium may be a prism, and the prism 21 includes a light incident surface 212 , a detection surface 211 and a light exit surface 213 , and the detection area is set on the surface of the detection surface 211 . The light beam from the light source module 1 is incident on the detection surface 211 of the prism 21 from the light incident surface 212, when the refractive index of the object 5 on the detection area is lower than the refractive index of the prism, and the incident angle of the light beam on the detection surface 211 satisfies a certain When conditions are met, the light beam is totally reflected on the detection surface 211 and exits from the light exit surface 213 . Optionally, the prism 21 is a triangular prism. Optionally, the prism 21 is an isosceles prism, such as an isosceles right-angle prism, so that the structure of the prism is more compact, making the overall structure smaller.

Optionally, antireflection coatings are provided on the light incident surface 212 and the light exit surface 213 of the prism to increase the transmittance of light beams. The prism 21 can be made of glass material, or can also be made of other transparent materials such as plastic and resin. Optionally, the size of the detection area matches the divergence angle of the outgoing light from the light source module 1, so that the light spot formed by the outgoing light on the detection area just covers the detection area or is slightly smaller than the detection area, so as to facilitate the small size of the refractometer change. In other examples, the first medium may also be other optical elements with a high refractive index, or be composed of other media with a high refractive index.

The field of view of the lens is determined by the focal length f and the aperture size d of the lens. However, to achieve a large refractive index detection range of the liquid to be measured, the refractometer not only depends on the field of view of the lens, but also needs to ensure that the light within the field of view It can be reflected by the reflective module and incident into the converging module, so the size of the light-emitting surface of the optical module needs to be increased accordingly. The angle range of the light beam that can finally be received by the converging module is jointly determined by the size of the light emitting surface of the light source module and the size of the converging module. A detailed explanation will be given below in conjunction with the equivalent optical system shown in FIG. 5 . In this equivalent optical system, the converging module 3 , the photosensitive array 4 and the processor are mirrored to the side of the reflective module facing away from the light source module 1 , and the converging module 3 is an example of an equivalent lens.

As shown in Figure 5, the angle range α that the photosensitive surface array 4 can detect is defined by two lines on the edge: the light r1 from the uppermost end of the light-emitting surface of the light source module 1 to the lowermost end of the clear aperture of the lens 3, and the light source r1 Light r2 from the lowermost end of the light-emitting surface of the module 1 to the uppermost end of the clear aperture of the lens. The angle range α is determined by three variables: the size of the light emitting surface of the light source module 1 , the clear aperture of the lens 3 , and the distance between the light emitting surface of the light source module 1 and the lens 3 . Therefore, in the case that the detection angle range α of the photosensitive surface array 4 is the same, compared with the refractometer with a slit design shown in FIG. Shared with the clear aperture of the lens. That is to say, when the detection angle range α of the photosensitive module in one dimension is the same, the aperture of the photosensitive module in the refractometer shown in Figure 1 in this dimension=the aperture of the light emitting surface of the light source module 1 in this application+lens of the clear aperture. Therefore, compared with the prior art, this application can realize a smaller light source module and photosensitive module under the same detection angle range, which can realize product miniaturization and reduce costs; moreover, this application can choose to share the photosensitive module by the size of the light source The size of the area array makes the size of the photosensitive area array very small, which has the advantages of low cost and small volume.

In an example, the aperture of the light emitting surface of the light source module 1 is greater than or equal to the aperture of the light of the converging module 3 . For example, as shown in FIG. 6 , the aperture of the light-emitting surface of the light source module 1 is the same as or less than 1/5 of the aperture of the light-emitting surface of the converging module 3 . Like this, under the same situation that the detection angle range α of photosensitive surface array 4 is the same, the aperture of the photosensitive surface array in the refractometer of the present application is half of the aperture of the photosensitive surface array of the refractometer in the prior art, can reduce the number of refractometers. cost and difficulty in mass production.

For another example, as shown in FIG. 7 , the aperture of the light emitting surface of the light source module 1 is larger than twice the aperture of the converging module 3 . In this way, under the condition that the detection angle range α of the photosensitive surface array is the same, the aperture size of the photosensitive surface array in the refractometer of the present application can be made very small. The cost and difficulty of mass production required by the size are much lower, and the cost and difficulty of mass production can be reduced to a greater extent by allowing the light source module to bear more dimensions.

Optionally, the detection angle range α of the photosensitive surface array covers the total reflection angle range of the reflection module, wherein the total reflection angle range of the reflection module refers to all angles where total reflection can occur in the reflection module, so as to ensure the large Refractive Index Detection Range. Optionally, the reflective module uses a medium with a high refractive index to reduce the total reflection angle range of the converging module. However, due to the serious dispersion of high refractive index glass, this is because when light of different wavelengths passes through the glass, the reflective module with high refractive index will cause a large change in the refractive index of light beams of different wavelengths, which in turn will cause the photosensitive array to obtain The total reflection boundary in the detected detection image will produce blurring, which will reduce the detection accuracy of the total reflection angle. In an example, the refractometer may use a light source module with a narrow wavelength bandwidth, or set a narrow-band filter on the outgoing light path of the light source module to reduce the wavelength bandwidth of the outgoing light from the light source module to reduce dispersion. For example, the outgoing light of the light source module or the outgoing light filtered by the narrow-band filter is a light beam with a full width at half maximum of 5 nm or less.

As shown in FIG. 8 , FIG. 8 is a detection image of the light beam received by the photosensitive surface array when the refractometer detects a liquid to be measured. The refractometer is placed in the liquid to be tested, so that the detection area is covered by the liquid to be tested, and the photosensitive array forms a detection image. As shown in FIG. 8 , the detection image includes a reflection area 81 and a non-reflection area 82 surrounding the reflection area 81 . The reflection area 81 includes a total reflection area 811 and a non-total reflection area 812 . Wherein, the total reflection area 81 refers to the area in the reflection area 81 of the detection image 8 where the light beam totally reflected by the total reflection interface 21 of the reflection module 2 is incident, and the non-total reflection area 812 refers to the area in the detection image 8 that is less than The total reflection angle is the incident area of the reflected light beam when incident on the total reflection interface 21 of the reflection module 2 . Since the reflected part of the non-totally reflected light beam suddenly drops in brightness compared with the fully reflected light beam, an obvious brightness mutation boundary 813 is formed at the junction of the total reflection area 812 and the non-total reflection area 811, and the brightness mutation boundary 813 Corresponding to the incident light beam at the total reflection angle at the total reflection interface 21 .

Due to the setting of the converging module, different pixel positions in the detection image correspond to beams emitted from the total reflection interface at different angles, so the processor can determine the brightness mutation boundary by obtaining the position of at least one pixel point in the brightness mutation boundary position, and then calculate the refractive index of the liquid to be measured according to the total reflection angle corresponding to the position of the brightness mutation boundary line.

In this application, since the lens module is added in front of the photosensitive array to decouple the position and direction of the light, the light source module does not need to be small, as long as there is light at a corresponding angle, it can be focused on the corresponding sensor position. Compared with the prior art, the light source module in this application does not need to bear the function of distinguishing angles and positions. In the prior art, since the divergence angle of the light source module is required to be relatively large, but the divergence angle of the LED light source itself is not very large, it is necessary to find a specially-made LED light source with a large angle and a small light-emitting surface in the solution of the prior art. However, in this application, the requirements for the light source module are much relaxed, and the large-angle light-emitting range can be realized by multiple LEDs+uniform light panels. In one example, as shown in FIG. 3 , the light source module 1 further includes a dodging sheet 6 located on one side of the light emitting surface. Since the photosensitive array perceives beams from different directions, the homogenization sheet can improve the uniformity of the beams in each direction, thereby improving the uniformity of the image formed by the photosensitive array, and can also avoid the measurement accuracy caused by inconsistent light intensities at different angles. Lowering the problem.

In some examples, the reflective module contains two adjacent media, and the two media may be media other than the first medium, or may include the first medium; Total reflection is formed between the two media, and then a sudden change in brightness is formed on the detection image except for the sudden change in brightness corresponding to the liquid to be measured. The calculation deviation of the refractive index of the liquid to be measured caused by the drift caused by the temperature change improves the calculation accuracy of the refractive index of the liquid to be measured. The structure of an example of the refractometer of the present application will be described below with reference to FIG. 9 .

Fig. 9 is a schematic structural diagram of an example of a refractometer. As shown in FIG. 9 , in this embodiment, the light source module 1 is used to emit the first light beam and the second light beam. The reflective module includes at least two media for receiving light beams from the light source module. Specifically, the reflection module includes a first medium 21 and a second medium 22 arranged adjacently. The refractive index of the first medium 21 is greater than that of the second medium 22 , and a first total reflection area exists between the first medium 21 and the second medium 22 . The reflective module also includes a detection area 23 disposed above the first medium 21 . Optionally, the second medium 22 and the detection area 23 are respectively arranged in different areas on the same surface of the first medium 21 .

The first medium is used for receiving the first light beam and the second light beam. Wherein, at least part of the first light beam is incident from the first medium 21 to the second medium 22, because the refractive index of the first medium 21 is greater than that of the second medium 22, and the emission angle of the first light beam is such that when the incident second medium The incident angle at 22 o'clock covers the total reflection angle, so at least part of the second light beam incident on the second medium 22 is totally reflected in the first total reflection area. When one side of the detection area 23 is covered with the liquid to be tested 5 , at least part of the second light beam is incident on the liquid to be tested from the first medium 21 . When the refractive index of the liquid to be measured is greater than the refractive index of the first medium 21, and the divergence angle of the second light beam satisfies that the incident angle when it enters the second medium 22 covers the total reflection angle, the second beam incident on the detection area 23 The part of the light beam that satisfies the total reflection condition is totally reflected on the detection area 23 .

Wherein, the light source module 1 may include one or at least one light emitting unit (such as LED). In the case where the light source module 1 includes a plurality of light emitting units, the first light beam and the second light beam can be from different emitting units in the light source module 1, or can be from different emission angles of all the emitting units in the light source module 1 Beam. In FIG. 9, the first light beam and the second light beam respectively come from light beams of different emission angles of all emission units in the light source module 1 for illustration. L121 in the light beam belongs to the first light beam, and total reflection occurs when it is incident on the second medium 21; light L112 in the light beam emitted by the emitting unit 11 and L122 in the light beam emitted by the emitting unit 12 belong to the second light beam, and total reflection occurs when it is incident on the detection area 23. reflection.

Optionally, the emission angle of the first light beam is such that all or at least 50% or more of the incident angle when entering the second medium 22 is greater than or equal to the total reflection angle, and then all or almost all total reflection occurs in the first total reflection area , to improve the brightness contrast of the brightness mutation boundaries. Optionally, the area of the second medium 22 matches the divergence angle of the first light beam, so that the light spot formed by the first light beam on the second medium 22 just covers the second medium 22 or is slightly smaller than the second medium 22 , to facilitate the miniaturization of the refractometer.

In the example shown in FIG. 9 , the first medium 21 is a triangular prism. The second medium 22 is a coating laid on one surface of the first medium 21 . The surface is divided into side-by-side first and second regions. The second medium 22 is fixed on the side facing away from the light source module on the first area, and the second medium 22 is not covered on the second area, which is the detection area 23. When the refractometer measures the liquid to be measured, the liquid to be measured Liquid covers this second area. Optionally, a liquid groove is provided on the surface of the first medium 21 , the second medium is provided on a part of the liquid groove by spraying process or printing process or other processes, and the remaining area of the liquid groove is set as the detection area 23 . In some examples, the second medium also needs to be waterproofed. For example, after the first area of the liquid tank is coated, a light-transmitting waterproof material (such as a glass sheet) 24 is added to cover only the first area, or to cover the entire liquid tank.

In some examples, the second medium may use a material whose refractive index varies with temperature and that of clear water with a high degree of correlation, which can improve the accuracy of correcting the refractive index of the liquid to be measured. Optionally, the value of the refractive index of the second medium varying with temperature is within -0.0003/deg C to 0.0003/deg C.

The second medium can be liquid, for example, clear water, which is sealed and fixed in the liquid tank on the surface of the triangular prism. The second medium may also be a solid, such as a photocurable coating, a high temperature curing coating, or a natural curing coating, and the like. The high temperature curing coating may be polytetrafluoroethylene (Poly tetrafluoroethylene, PTFE) after high temperature curing. The naturally cured coating can be a naturally cured fluorocarbon resin FEVE coating. The photocurable coating can be a shadowless adhesive after photocuring. The characteristics of the change of refractive index of the shadowless glue with temperature and the characteristics of the change of the refractive index of clear water with temperature are highly correlated. Using the measurement results of the shadowless glue to correct can improve the measurement accuracy of the refractive index of the liquid to be tested. As shown in Figures 10a-c, Figures 10a-c are schematic diagrams of the experimental results of the variation of the refractive index of a shadowless glue and clear water with temperature. Among them, Figure 10a is a schematic diagram of the experimental results of the drift of the refractive index of the shadowless glue with the increase of temperature, Figure 10b is a schematic diagram of the experimental results of the drift of the refractive index of clear water with the increase of temperature, Figure 10c shows the refractive index difference at each temperature Schematic representation of the distribution of values. Among them, the ordinate in Fig. 10a-c represents the position of the brightness mutation boundary line corresponding to the refractive index in the detection image, and the abscissa is the number; different positions correspond to different refractive indices, and different times correspond to different temperatures. It can be seen from the figure that there is a high degree of correlation between the characteristics of the refractive index of Wuying glue and clear water changing with temperature. Moreover, the shadowless adhesive has the advantages of high light transmittance and low expansion rate. Optionally, the refractive index of the shadowless adhesive after curing is greater than 1.33 and not greater than 1.6.

There may be various positional relationships between the first area and the second area of the first medium. In the embodiment shown in FIG. 9 , the divergence angle of the light beam emitted by the light source module 1 is the largest or close to the largest in the section parallel to the paper surface, and the divergence angle is the smallest in the section perpendicular to the paper surface. Coordinating with the outgoing light of the light source module, the first area and the second area are arranged along the width direction of the two areas (also a direction perpendicular to the paper surface), and the second area is arranged in the length direction of the two areas (also parallel to the direction of the paper). The cross-section on the page) can cover the divergence angle of the light emitted from the light source module 1 . In this way, the range of the total reflection angle that can be measured in the second area can be realized to be larger, thereby increasing the refractive index measurement range, and the first imaging area and the first light beam in the imaging of the second light beam in the photosensitive surface array 4 can also be made The overlapping area of the second imaging area in the imaging of the photosensitive surface array 4 is relatively narrow, which reduces the degree of mutual interference between the first imaging area and the second imaging area. Of course, the first area and the second area can also be in other positional relationships. In this embodiment, as long as the first area can cover the total reflection angle corresponding to the second medium, the second area can preferably cover the area where the first light beam is as large as possible. Incidence angle range to achieve a larger range of refractive index measurement.

The total reflection of the first light beam in the first total reflection area will cause the first brightness mutation boundary to be fixed in the imaging of the photosensitive surface array. The total reflection between the media will cause the formation of the second brightness abrupt boundary line in the imaging of the photosensitive surface array. Specifically, the imaging of the photosensitive surface array includes a first imaging area corresponding to the incidence of the first light beam and a second imaging area corresponding to the incidence of the second light beam. The first imaging area includes areas located on both sides of the first luminance mutation boundary line. One side has a higher brightness, corresponding to a partial beam of total reflection (for the convenience of description, hereinafter referred to as a total reflection area), and the other side has a lower brightness, corresponding to a non-total reflection area. Reflected part of the light beam (for the convenience of description, hereinafter referred to as the non-total reflection area). Similarly, the second imaging area includes a total reflection area and a non-total reflection area located on both sides of the boundary line of the second sudden change in brightness.

Wherein, as shown in FIG. 11, the first imaging area P1 and the second imaging area P2 can be two areas separated from each other in the imaging without intersection, which can reduce the gap between the first sudden brightness boundary line L1 and the second sudden brightness boundary line L2. Mutual interference of each other makes it easier for the processor to detect the two boundary lines. Or, as shown in Figure 12, there may also be two overlapping or even overlapping regions in the imaging. In this case, as long as the refractive index of the liquid to be measured is different from that of the second medium, the first brightness abrupt boundary line L1 and the second medium The positions of the two sudden brightness boundary lines L2 may be different, and the processor may identify the first sudden brightness boundary line and the second sudden brightness boundary line respectively through the change of brightness. Optionally, the first brightness mutation boundary line is located near the edge in the detection image. Optionally, the detection image includes a first edge and a second edge opposite to each other, wherein the closer the brightness mutation boundary line in the detection image is to the first edge, the higher the refractive index is, and the first brightness mutation boundary line is located in the detection image Between the first edge and the luminance mutation boundary line corresponding to the maximum refractive index in the refractometer's refractometer measurement range; this can ensure that the refractometer's refractometer has the largest refractometer measurement range when the FOV of the photosensitive array is fixed. Optionally, the distance between the first brightness mutation boundary line and the first edge is greater than 1/10 of the width of the detection image, and the distance between the brightness mutation boundary line corresponding to the maximum refractive index measurement range of the refractometer is greater than 1/8 of the width, The measurement accuracy of the first luminance sudden change boundary and the measurement accuracy of the second luminance sudden change boundary can be guaranteed at the same time.

There are many ways to realize that the first imaging area and the second imaging area are two areas that are separated from each other and have no intersection. In some examples, the optical paths of the second beam and the first beam can be separated by setting a structure on the optical path before the converging module 3 , so that the first imaging area and the second imaging area are two areas separated from each other. For example, in the example shown in FIG. 9 , a light entrance 2111 is provided on the light incident surface of the triangular prism 21 to limit the light beam from the light source module 1 to enter the interior of the triangular prism 21 only through the light entrance 2111 . The light exit surface of the triangular prism 21 is provided with a first light exit 2121 and a second light exit 2122 for light beam exit, and areas other than the first light exit 2121 and the second light exit 2122 are provided with materials that reflect light beams or absorb light beams . Wherein, the first light outlet 2121 is located on the optical path of the first light beam which is totally reflected and reflected by the second medium 22, and the second light outlet is located on the optical path of the second light beam which is totally reflected and reflected by the liquid to be measured on the detection area 23 .

In one example, as shown in FIG. 13 , FIG. 13 is an example of a top view of the refractometer shown in FIG. 9 . In this example, the lower edge of the first light outlet 2121 is located above the extension line where the upper edge of the light inlet 2111 is located, and the upper edge of the second light outlet 2122 is located below the extension line where the lower edge of the light inlet 2111 is located, so that Reduce the proportion of the first light beam exiting from the first light exit port 2121, and greatly reduce the proportion of the second light beam exiting from the second light exit port 2122, so that the light beam exiting from the first light exit port 2121 and the light beam exiting from the second light exit port 2122 The light beams are converged by the converging module and respectively incident on two different areas of the photosensitive array, so that the first imaging area and the second imaging area formed on the photosensitive array are separated without overlapping.

Of course, the lower edge of the first light outlet and the upper edge of the second light outlet may not be subject to this restriction, even if the second light beam and the first light beam emitted from the light outlet of the reflection module cannot be completely separated, compared with the light beam without the light outlet In the solution, the degree of mutual interference between the first imaging area and the second imaging area can still be reduced.

The first light outlet and the second light outlet can be realized by silk screen printing on the light outlet surface of the converging module, or by installing structural components on the light outlet surface or one side of the light outlet surface of the converging module, which is not limited here.

In some examples, due to the light distribution characteristics of the light emitted by the light source, the brightness of the central area of the photosensitive array is different from the brightness of the surrounding area. Optionally, different photosensitive units in the photosensitive array or photosensitive units in different regions adopt different exposure parameters (such as different exposure intensities, different exposure durations or different exposure times) to improve the brightness of the darker areas, and then Improve the detection signal-to-noise ratio.

In some examples, the positional relationship between the second medium and the detection area may not be arranged side by side on the same surface of the first medium, but arranged in a stacked relationship. For example, the second medium is a coating laid on one surface of the first medium, and the detection area is set above the second medium facing away from the first medium.

Both the first light beam and the second light beam are sequentially incident on the first medium, the second medium and the detection area. Among them, the gap between the first medium and the second medium is mainly used to make the first light beam produce total reflection, so as to form the first brightness abrupt boundary line on the detection image; the gap between the second medium and the liquid to be tested on the detection area is mainly used for The second light beam is totally reflected to form a second boundary line of abrupt change in brightness on the detection image. Wherein, the total reflection angle of the light beam between the first medium and the second medium (for convenience of description, hereinafter referred to as the first total reflection angle) needs to be greater than the total reflection angle between the second medium and the liquid to be measured (for description For convenience, hereinafter referred to as the second total reflection angle), therefore, the second medium is preferably a material with a refractive index greater than the highest point of the measuring range of the liquid to be measured.

Optionally, by shaping the outgoing light of the light source module 1 or adjusting the luminance of different light-emitting elements of the light source module 1, the incident angle of the outgoing light of the light source module 1 when incident on the second medium 22 is smaller than the first total reflection angle The proportion of the portion is greater than 50%, so as to reduce the brightness dimming of the second brightness mutation boundary corresponding to the liquid to be measured caused by the large attenuation of the emitted light of the light source module 1 after passing through the second medium.

Since the refractometer generally requires waterproofing, the second medium can also be made of a material with a waterproof function, and also has a waterproof function, so as to seal the first medium in the refractometer. Or, optionally, the side of the second medium facing away from the first medium is also provided with a light-transmitting waterproof member, which is used to seal the first medium and the second medium in the refractometer, and the detection area is arranged on the back of the waterproof member. on the side surface towards the second medium. Moreover, the waterproof part can be made of a material with a higher refractive index to widen the gap with the refractive index of the liquid to be measured, thereby reducing the ambient light entering the refractometer and reducing the impact of ambient light on the measurement results. Optionally, the refraction index of the waterproof member is greater than the maximum refraction index in the refractometer measurement range.

In the example with a waterproof part, because the excessive thickness of the waterproof part will affect the heat conduction, the temperature of the liquid to be tested and the second medium cannot be kept basically the same, which will affect the self-calibration effect; and the too thin waterproof part will affect The hardness of the waterproof part. Optionally, the thickness of the waterproof member is between 0.05 mm and 3 mm, which can ensure heat conduction and hardness at the same time.

Compared with setting the positional relationship between the second medium and the detection area as the same layer, setting the positional relationship between the second medium and the detection area as the upper and lower layers can simplify the difficulty of the process, make it easier to achieve waterproofing, and reduce the cost. The waterproof part can adopt glass sheet or other light-transmitting and waterproof materials. Wherein, the refractive index of the waterproof member may be larger than that of the second medium, or smaller than that of the second medium. The first medium is a triangular prism, and the second medium is a coating on the surface of a triangular prism. Of course, the first medium and the second medium in this application can also refer to other components, and further examples will be described below. . The three examples are explained below with reference to FIGS. 14 to 17 respectively. As shown in Fig. 14, Fig. 14 is a schematic diagram of the positional relationship between the triangular prism, the coating on the surface of the triangular prism, the waterproof member and the liquid to be measured.

Example 1: The first medium is a prism, and the second medium is a coating. The refractive index of the second medium is greater than that of the waterproof member. Since the total reflection occurs when the light beam enters the optically sparse medium from the optically dense medium, the light beam passes through the first medium, the second medium, the waterproof member, and the liquid to be tested in sequence, and the refractive index of the liquid to be tested is less than When the refractive index of the waterproof part is high, when the light beam covers all the total reflection angles between two adjacent layers, total reflection will occur between any two adjacent layers, and then a corresponding brightness mutation boundary will be formed in the detection image. As shown in FIG. 15, FIG. 15 is a schematic diagram of a detection image. In the detection image, M1 is the boundary line of abrupt change in brightness produced by the total reflection of the beam between the first medium and the second medium, which can be used to calculate the refractive index of the second medium. M2 is the sudden change in brightness produced by the total reflection of the light beam between the second medium and the waterproof part, which can be used to calculate the refractive index of the waterproof part. M3 is the sudden change in brightness produced by the total reflection of the light beam between the waterproof part and the liquid to be tested, which can be used to calculate the refractive index of the liquid to be tested. The three luminance mutation boundary lines are arranged sequentially from left to right in the image.

Optionally, by setting the positional relationship between the photosensitive surface array 4 and the converging module 3, the position of the light beam totally reflected by the first total reflection area after being converged by the converging module 3 is located outside the photosensitive surface array 4, so that the detected Only M2 and M3 can be displayed in the image, as shown in Figure 16. This can further reduce the interference of the first sudden brightness boundary line on the detection of other sudden brightness boundary lines; moreover, the distance between M2 and the right edge of the image is increased, which can increase the measurement range of the refractive index of the liquid to be measured.

Example 2: The first medium is a prism, and the second medium is a coating. The refraction index of the waterproof member is greater than or equal to the refraction index of the second medium. When the refractive index of the liquid to be measured is smaller than that of the waterproof member, under the condition that the light beam covers all the total reflection angles between two adjacent layers, it will be between the first medium and the second medium, as well as the waterproof member and the waterproof member. Total reflection occurs between the measured liquids, and then the corresponding brightness mutation boundaries are formed in the detection image. As shown in FIG. 17, FIG. 17 is another schematic diagram of the detection image. In the detection image, M4 is the boundary line of abrupt change in brightness produced by the total reflection of the beam between the first medium and the second medium, which can be used to calculate the refractive index of the second medium. M5 is the sudden change in brightness produced by the total reflection of the light beam between the waterproof part and the liquid to be tested, which can be used to calculate the refractive index of the liquid to be tested.

Compared with Example 1, in Example 2, since one boundary line of sudden brightness change is reduced in the image, the interference to the detection of the other two sudden change of brightness lines can be reduced, and the measurement range of the refractometer can be increased.

Example 3: the first medium is the coating on the surface of the triangular prism, the second medium is the waterproof element, and the refractive index of the coating is greater than that of the waterproof element. Therefore, the first total reflection area refers to the total reflection of the first light beam between the coating and the waterproof member, which corresponds to the generation of the first abrupt change in brightness. The second sudden change boundary line of brightness is generated by the total reflection of the second light beam between the waterproof member and the liquid to be tested on the detection area. The processor corrects the second brightness mutation boundary line corresponding to the refractive index of the liquid to be measured through the first brightness mutation boundary line formed by the total reflection light beam occurring in the first total reflection area. In this example, the coating is preferably made of a material whose refractive index drifts with temperature in a direction opposite to that of clear water.

In the example where the positional relationship between the second medium and the detection area is set as the upper and lower layers, since the light beam has undergone a total reflection between the first medium and the second medium, the total reflection between the second medium and the liquid to be measured The reflected light beam will attenuate more, which may lead to the possibility that the boundary line of the second sudden change in brightness is much darker than the boundary line of the first sudden change in brightness, resulting in a lower signal-to-noise ratio.

In one example, the photosensitive area array is used to continuously output a detection image sequence including multiple frames of detection images, wherein different exposure parameters are used for two adjacent frames of the detection image photosensitive area array. The exposure parameters may include exposure intensity, exposure duration or exposure times. The processor is also used for synthesizing one frame of images for detection according to the two adjacent frames of detection images, so as to increase the brightness of the second sudden brightness boundary line and improve the signal-to-noise ratio.

In one example, the photosensitive array is used to continuously output a sequence of detection images including multiple frames of detection images, wherein the luminous intensity of the light source module is different during two periods in which two adjacent frames of detection images are respectively formed by the corresponding photosensitive array. In this way, by increasing the luminous intensity of the light source module corresponding to one frame of the detection image, the intensity of the light beam totally reflected between the second medium and the liquid to be measured can be increased, thereby increasing the brightness of the second brightness mutation boundary line, while avoiding the first Saturation of the boundaries of a sudden change in brightness while avoiding an increase in the signal-to-noise ratio.

In each of the above examples, the refractive index of the liquid to be measured is calculated by the sudden change in brightness formed on the image by the total reflection caused by the liquid to be measured in the refractometer, and the second medium is set to cause the total reflection of the light beam to form in the image. The brightness mutation limit is used to correct the refractive index of the liquid to be tested. Optionally, the refractometer may be further provided with at least one additional medium to induce total reflection of the light beam to form an additional at least one brightness abrupt boundary line on the image for correcting the refractive index of the liquid to be tested. For example, in the embodiment shown in FIG. 9, at least a third medium, a second medium, and a detection area are arranged side by side on the surface of the first medium, and the third medium is used to receive the third light beam from the light source module, It is used to induce the total reflection of the third light beam, and then form a new boundary line corresponding to the sudden change in brightness of the third medium on the image. For another example, there is at least a third medium, a first medium, a second medium, and a detection area in a layered arrangement, and the third medium is used for triggering a light beam when it is incident on the third medium or when it is incident from the third medium. Total reflection occurs when another adjacent medium is used, and then a new boundary line corresponding to the sudden change in brightness of the third medium is formed on the image.

When correcting the refractive index of the liquid to be measured, the stronger the correlation between the characteristics of the refractive index of the medium used for calibration and the characteristics of the temperature change of the liquid to be measured is, the higher the refractive index of the liquid to be measured is corrected. The higher the accuracy. By setting two or more media for correcting the refractive index of the liquid to be tested, the medium that is more related to the characteristics of the liquid to be tested can be selected when calibrating the liquid to be tested, and the efficiency of the refractive index correction of the liquid to be tested can be improved. Accuracy. In the example where two or more media are used to correct the refractive index of the liquid to be tested, one of the liquids to be tested is selected in the image according to the brightness mutation boundaries corresponding to the two or more media respectively When correcting the refractive index of the medium, you can choose the one that is closest to the sudden change boundary of brightness corresponding to the liquid to be tested, or fit a new brightness according to the sudden change boundaries of brightness corresponding to the two or more media respectively. The mutation boundary line is used for correction, or a machine learning method may be used to select or generate a brightness mutation boundary line for correction.

There are a number of ways for the processor to determine the location of the abrupt brightness boundary in the detected image. For example, the processor may separately calculate the brightness gradient change of each pixel row in the reflection area in the detection image, and determine the pixel point with the largest gradient change in each row of pixels as the point on the boundary line of the sudden brightness change. Alternatively, the processor may also acquire the position of the boundary line of sudden brightness changes through methods such as edge detection, template matching, and machine learning. Optionally, in the process of obtaining the position of the sudden brightness change boundary, the processor may also obtain the current temperature and/or the boundary deviation caused by the assembly tolerance, and compare the obtained brightness sudden change boundary according to the current temperature and/or the boundary deviation position to compensate. After determining the boundary line of abrupt change in brightness, the processor can look up the corresponding relationship table between the boundary line of sudden change in brightness and the refractive index that has been calibrated in advance to obtain the corresponding refractive index.

The processor determines the first sudden change in brightness boundary and the second sudden change in brightness from the detection image, and calculates the refractive index of the liquid to be tested according to the position of the second sudden change in brightness. The refractive index of the liquid to be measured is corrected. There are many ways to correct the refractive index of the liquid to be measured according to the position of the first brightness mutation boundary line. For example, the processor stores a relationship function of the distance between the first sudden change in brightness boundary line and the second sudden change in brightness boundary line corresponding to the liquid to be tested and the drift compensation. The drift distance for compensating the second sudden change in brightness can be determined through the relationship function, so that the second sudden change in brightness returns to a position at a certain fixed temperature (for example, 20° C.). Alternatively, other methods, such as a machine learning method, may be used to correct the refractive index of the liquid to be measured according to the position of the first brightness mutation boundary.

In one example, the photosensitive area array may be a complementary metal oxide semiconductor (Complementary Metal Oxide Semiconductor, CMOS) sensor array. Of course, the photosensitive area array can also be realized by using other photoelectric sensors such as CCD image sensors. Optionally, after the photosensitive array outputs the detection image, the processor counts the brightness of the detection image according to the detection image, and calculates the refractive index according to the detection image only after the brightness of the detection image satisfies a preset condition. There may be various preset conditions. For example, the preset condition includes that the absolute value of the difference between the detected image brightness and the preset target brightness is greater than a threshold.

Compared with the use of linear arrays as photosensitive arrays in the prior art, the use of CMOS sensor area arrays can not only greatly reduce the installation requirements, but also add many things that the previous one-dimensional arrays could not do through the nature of the two-dimensional array. For example, before calculating the refractive index based on a frame of detection image detected by the photosensitive surface array, the processor can perform noise filtering according to pixel values measured by multiple rows of sensors corresponding to the photosensitive surface array in a frame of detection image to improve the signal-to-noise ratio. Wherein, the processor may perform noise filtering on the frame detection image in the space domain or the transformation domain. When filtering noise, the processor can perform noise filtering based on window sliding average filtering. The width of the filtering window can be a value between 1 and the width of the detected image, and the height can be a value between 1 and the height of the detected image. In a specific example, the processor may perform weighting processing (for example, averaging processing) on the pixel values detected by the multi-row sensors to obtain a noise-filtered result, and then calculate the refractive index of the medium to be detected according to the noise-filtered result. Certainly, the processor may also adopt other noise filtering methods, for example, adopting a machine learning method to filter noise of the frame detection image.

As shown in Figure 18, the left side of Figure 18 is the pixel value curve of a pixel row on the detection image formed by the light beam received by the photosensitive surface array, and the right side is the average of the pixel value of the row and the pixel values of the upper and lower rows From the pixel value curve obtained afterwards, it can be seen that the influence of noise can be reduced after averaging processing with the pixel values of multiple rows. Compared with only one line of pixel values in the prior art (that is, only the detection results of the line array sensor), the use of a photosensitive surface array in this application can increase the accuracy of measurement.

For another example, when calculating the refractive index of the medium to be measured based on multiple rows of pixel values in the reflection area in the detection image, the processor can eliminate one or more rows of pixel values affected by stray light, or reduce the pixel values affected by stray light. Influence weights for row or rows of pixel values.

A line of measurement results less affected by stray light can be selected from a frame of detection images to calculate the refractive index of the medium to be measured. Stray light is the interference light formed in the optical system due to surface wear, dirt, fog condensation or device position deviation. The presence of stray light will reduce the calculation accuracy of the refractive index. Using the photosensitive area array, the processor can determine the pixel row affected by stray light by comparing and analyzing the brightness of multiple rows of pixel rows. Compared with the linear sensor in the prior art, the photosensitive area array in this application can improve the accuracy of refractive index measurement. Optionally, the processor can also determine the pixel rows affected by stray light by comparing and analyzing multiple frames of detection images. This is more robust for refractive index measurements in the presence of stray light.

In an example, before calculating the refractive index, the processor may also perform noise filtering according to multiple frames of detection images. For example, after the photosensitive array collects multiple frames of detection images, the processor can perform weighted sum processing on the multiple frames of detection images to synthesize a frame of detection images, and then use the synthesized detection images to calculate the refractive index. Optionally, before calculating the refractive index, the processor may also use the single-frame noise filtering method described above to perform further noise filtering on the synthesized detection image.

In an example, the control module can also obtain brightness information of the current measurement environment, and adjust the detection image quality of the photosensitive area array according to the brightness information, so as to obtain a better measurement quality. Wherein, the control module can adjust at least one of the following items according to the brightness information: the output light intensity of the light source module, the exposure time of the photosensitive array, the analog gain of the photosensitive array, and the digital gain of the photosensitive array. Wherein, the photosensitive surface array can be used to measure the ambient light in a time period other than measuring the total reflected light, or, the detection module is also provided with other sensors for measuring the brightness information of the current environment.

In one example, a first temperature sensor and a second temperature sensor are arranged in the refractometer, wherein the first temperature sensor is used to measure the temperature of the second medium, and the second temperature sensor is arranged on the detection area to measure the temperature of the liquid to be tested. temperature. Alternatively, the first temperature sensor and the second temperature sensor may not be in direct contact with the second medium or the liquid to be measured, but may be in contact with a material with better thermal conductivity as a medium. Optionally, the first temperature sensor may be installed on the surface of the prism, and the processor is further configured to calculate the temperature of the second medium according to the temperature of the surface of the prism measured by the first temperature sensor. In the actual process, it is more difficult to fix the first temperature sensor on the surface of the second medium. The difficulty of the process can be reduced by installing it on the surface of the prism, and then calculate the temperature of the second medium through the temperature measured on the surface of the prism and the preset model. temperature.

The processor is also used to obtain the measurement results of the first temperature sensor and the second temperature sensor, so as to further correct the refractive index of the liquid to be measured. Since the refractive index of the liquid is related to the temperature of the liquid, and the temperature of the prism determines the ratio of thermal expansion and contraction of the prism, and the temperature of the prism will cause the deviation of the incident and outgoing angles of the beam, therefore, through the pre-established The relationship model between the temperature of the liquid to be measured, the temperature of the reflection module and the refractive index of the liquid to be measured is calculated according to the obtained temperature of the liquid to be measured, the temperature of the reflection module and the relationship model when calculating the refractive index of the liquid to be measured. Measuring the refractive index of liquid can improve the accuracy of refractive index calculation.

For example, in an application scenario where the temperature difference between the second medium of the refractometer and the liquid to be measured is small, the temperature deviation can be calculated through the first temperature sensor and the second temperature sensor, and the first brightness change boundary line is used for the second temperature difference. When correcting the position of the sudden change boundary line of brightness, by introducing the temperature deviation, the measurement result of the liquid to be tested can be corrected more accurately. Or, in the application scenario where the temperature difference between the second medium of the refractometer and the liquid to be measured is relatively large (such as the scene of measuring a high-temperature liquid to be measured at room temperature), when the liquid to be measured is measured, due to the large temperature difference The temperature conduction is relatively slow. Through the setting of two temperature sensors, the two temperatures can be measured more accurately, and then the temperature of the second medium and the liquid to be measured when they reach thermal equilibrium can be calculated. Or, further, the temperature change trend of the second medium and the liquid to be tested can also be obtained according to the temperatures measured by the two temperature sensors, and the temperature change trend of the second medium and the liquid to be tested can be predicted more accurately through the preset temperature change model The temperature change of the liquid to be tested is corrected in combination with the temperature change.

In an example, the processor can also calculate the turbidity of the liquid to be tested according to the detection image output by the photosensitive array. Among the outgoing light from the light source module, the light beam transmitted from the reflective module to the liquid to be measured will be scattered when encountering suspended particles in the liquid to be measured, and part of the scattered light will be transmitted through the reflective module and then incident on the photosensitive array. Scattering is divided into Rayleigh scattering, Mie scattering, and refraction with different angular components according to the size of the scattering particles. By analyzing the detection image detected by the photosensitive area array, the processor can obtain the light intensity distribution of the detection image, and obtain the size and properties of the scattering particles according to the light intensity distribution, and then judge the turbidity of the liquid.

For example, as shown in Figure 8, scattering caused by particles in the liquid can cause luminance values to appear on non-reflective areas where luminance should not be present. Thus, the processor can calculate the particle concentration of the liquid from the brightness on this non-reflective area. Specifically, since different pixel positions in the detection image correspond to light beams incident at different angles on the total reflection interface, on the non-reflection area in the detection image, it can be understood that the non-reflection area includes a total reflection area and a non-total reflection area, In FIG. 8 , the total reflection area of the non-reflection area is located on the upper and lower sides of the total reflection area of the reflection area, and the non-total reflection area of the non-reflection area is located on the upper and lower sides of the non-total reflection area of the reflection area. Since the light beam scattered by the particles in the liquid to be measured can only re-enter the reflection module at an angle within the total reflection angle, only the area corresponding to the area smaller than the total reflection angle will appear in the detection image formed by the photosensitive surface array. That is, the scattered light beam will only appear in the non-total reflection area in the detection image.

Therefore, in an example, the processor may calculate the scattered brightness according to the brightness of the non-total reflection area in the non-reflection area on the detection image. Optionally, the processor may also use the brightness of the total reflection area in the non-reflection area as a reference value to calculate the absolute value of the scattering brightness. For example, the processor may subtract the brightness of the total reflection area in the non-reflection area from the brightness of the non-total reflection area in the non-reflection area on the detection image to obtain the absolute value of the scattering brightness. After obtaining the scattering brightness, the processor can obtain the corresponding turbidity of the liquid to be measured according to the pre-established corresponding relationship model between the scattering brightness and the liquid turbidity.

Optionally, when the processor determines the brightness of the total reflection area in the non-reflection area, it may perform weighted average processing on the brightness of at least some pixels in the area to obtain the brightness of the total reflection area. Similarly, when determining the brightness of the non-total reflection area in the non-reflection area, weighted average processing may be performed on the brightness of at least some pixels in the area to obtain the brightness of the non-total reflection area. This reduces calculation errors.

For another example, as shown in Figure 8, the scattering caused by particles close to the total reflection interface of the reflection module will cause the boundary line of the brightness change in the reflection area in the detection image to be blurred, so the processor can also obtain the photosensitive surface array detection The degree of fuzziness of the sudden change boundary of brightness on the detected image is determined, and the turbidity in the liquid to be tested is determined according to the degree of fuzziness. Wherein, the processor can look up a table according to the corresponding relationship between the fuzzy degree of the pre-calibrated brightness mutation boundary and the turbidity of the liquid to obtain the corresponding turbidity of the liquid to be measured.

In some examples, the processor is used to calculate the turbidity of the liquid according to the brightness on the non-reflection area in the detection image when the concentration of the liquid to be tested is lower than a preset concentration, and when the concentration of the liquid to be tested is higher than a preset concentration The turbidity of the liquid is calculated according to the fuzzy degree of the boundary line of the sudden change in brightness on the detection image. When the concentration of the liquid to be tested is low, the turbidity of the liquid to be tested has a good linear relationship with the brightness of the non-reflective area in the detection image, and the calculation of turbidity according to the brightness of the non-reflective area can have higher accuracy , when the concentration of the liquid to be measured is high, the linear relationship decreases, and it is more accurate to calculate the turbidity through the fuzziness of the brightness mutation boundary.

Calculating turbidity with a refractometer can have many applications. In some examples, refractometers can be used to perform compositional testing of liquids. For example, a refractometer can simultaneously measure the refractive index and turbidity of a liquid to determine its properties. For another example, a refractometer can measure the refractive index and turbidity of a liquid (such as coffee) at the same time, and judge the sugar content and milk content of the liquid. As another example, a refractometer can simultaneously measure the refractive index and turbidity of a liquid (such as fruit juice) to determine the sugar content and pulp content of the liquid. As another example, a refractometer can measure the refractive index and turbidity in the clear liquid of the sensor, which can be used to determine whether the sensor is dirty. Optionally, the dirty judgment result can be used to decide whether to continue cleaning. In one application scenario, the refractometer can be used for cleaning machines (such as dishwashers, washing machines, etc.), and detect the refractive index and turbidity of the liquid after cleaning the object to judge the cleanliness of the cleaned object. In one application scenario, refractometers can be used for water quality detection. The judgment result of the refractometer can be displayed to the user through the interactive module.

Since the change of the turbidity of the liquid to be measured will also affect the refractive index of the liquid to be measured, in some examples, the processor is also used to calculate the turbidity of the liquid to be measured according to the pre-calibrated turbidity The influence relationship of the refractive index is used to correct the refractive index of the liquid to be measured. For example, in an application scenario, when the refractometer measures the turbidity and sugar content of the liquid to be tested together, the ratio of milk and sugar in the liquid to be tested can be distinguished by measuring the turbidity and sugar content of the liquid to be tested simultaneously to obtain Accurate milk volume and brix values can then more accurately calculate the calorie content of the liquid to be tested.

In one example, the refractometer also has a standby mode and/or a low power mode. In this standby mode, the control module is in a sleep standby state, the light source module and the photosensitive array are both powered off, and the overall power consumption of the refractometer is at the uW level. In the low power consumption mode, the control module is used to control the light source module and the photosensitive array to strobe synchronously, the power-on time is extremely short, and the overall power consumption of the refractometer is at the mW level. Specifically, when the control module controls the light source module 1 and the photosensitive array, it can synchronously trigger a pulse width modulation (PWM, Pulse Width Modulation) signal according to the frame signal of the photosensitive array to realize dimming of the light source module.

In some examples, the refractometer further includes at least one of the following: a colorimeter for detecting the color of the liquid to be tested, an impedance meter for detecting the content of ions (such as acid ions) in the liquid to be tested, and an impedance meter for detecting the color of the liquid to be tested. A PH value meter for measuring the acidity value of the liquid, so that the processor can assist in determining the type of the liquid to be tested based on the information.

In one example, the refractometer also includes a wireless communication module, which is used to send at least one of the refractive index, turbidity, and temperature of the liquid to be measured obtained by the processor to other clients (such as small programs in mobile phones, application, computer client, server, etc.), so that the client can display or analyze the collected data from one or more refractometers. In one example, the refractometer further includes an interactive module for displaying the detected data to the user.

The present application also provides a detection device, which is provided with the above-mentioned refractometer. For example, the detection container is a smart cup. As shown in FIG. 19, FIG. 19 is a schematic structural diagram of a smart cup. The smart cup includes a cup body and the above-mentioned refractometer 201 arranged in the cup body for detecting the refractive index and/or turbidity of the liquid in the water cup. As shown in FIG. 19 , the refractometer 201 is arranged at the bottom of the cup body 200 . Or, optionally, the refractometer is fixed at the cup lid in the cup body, which can be installed conveniently. When it is necessary to measure the refractive index of a liquid, the user only needs to invert the water cup covered with the lid to realize the measurement immediately. The refractometer can be an independent module fixed in the cup body of the smart cup. In this way, the refractometer and the cup body of the smart cup can be assembled independently, and the structure and waterproof process are simpler. Or, the refractometer can be integrated in the cup body of the smart cup. Optionally, in the above example in which the refractometer includes waterproof parts, the refractometer may be embedded inside the glass cup, and the cup wall is used as the waterproof part of the refractometer.

Optionally, the smart cup is also provided with a micro-pressure sensor and a computing module. The micro-pressure sensor is used to detect the volume of the liquid in the water cup, and the calculation module is used to calculate the calorie of the liquid in the water cup according to the refractive index and/or turbidity of the liquid measured by the refractometer. Optionally, the micro-air pressure sensor is arranged in a closed space formed between the bottom of the cup body and the diaphragm arranged on the bottom.

For another example, the detecting device is an intelligent scale. As shown in Fig. 20, Fig. 20 is a structural schematic diagram of a smart scale. The smart scale includes a scale body 210 and the above-mentioned refractometer 211 arranged in the scale body 210, the surface of the scale body 210 is also provided with a liquid accommodating area 212 and a first display area (not shown), the refractometer 211 It is used to detect the refractive index of the liquid in the liquid accommodating area 212 , and the first display area is used to display the refractive index of the liquid. Optionally, the surface of the smart scale is also provided with a weighing area 213 and a second display area (not shown in the figure), and the second display area is used to display the weight of the object on the weighing area. Optionally, the weighing area 213 and the liquid containing area 212 are arranged side by side on the surface of the smart scale. Optionally, the first display area and the second display area are set separately or combined.

For another example, the detection device is an intelligent animal urine detector (mat, etc.), equipped with the above-mentioned refractometer, and measures the refractive index of animal urine by the refractometer.

The present application also provides a method for detecting the refractive index of the liquid to be measured by using a refractometer. As shown in FIG. 21 , FIG. 21 is a schematic diagram of an embodiment of a method for detecting the refractive index of a liquid to be measured by using a refractometer in the present application. The method includes the following steps: S2201, sending a light beam to a reflection module in the refractometer. S2202. Converge the light beam at least totally reflected by the reflective module to the photosensitive array located on the focal plane of the converging module through the converging module. S2203. Using the photosensitive array to image the received light beam to generate a detection image. S2204. Determine, according to the detection image, a boundary line of a sudden change in brightness in the detection image. S2205. Determine a corresponding total reflection angle according to the position of the abrupt brightness boundary line in the detection image. S2206. Determine, according to the total reflection angle, the refractive index of the medium corresponding to the boundary line where the sudden brightness change occurs.

In an example, the refractometer further includes a detection area arranged on a surface of a medium in the reflection module, when the detection area is covered with the liquid to be measured, and the refractive index of the liquid to be measured is lower than the When the refractive index of the first medium is lower, at least part of the light beam is totally reflected by the liquid to be tested; only one boundary line corresponding to the sudden change in brightness corresponding to the refractive index of the liquid to be measured is formed in the detection image.

In an example, the light beam includes a first light beam and a second light beam, and the reflective module includes a first medium and a second medium adjacently arranged, and the refractive index of the first medium is greater than that of the second medium , the first light beam is incident from the first medium to the second medium, and is at least partially totally reflected by the second medium; the refractometer also includes a detection area, which is arranged in the reflection module The surface of a medium is used to receive the second light beam; when the detection area is covered with the liquid to be tested, and the refractive index of the liquid to be tested is lower than that of one of the mediums, the second beam At least part of the two light beams are totally reflected by the liquid to be tested; a first sudden change boundary line of brightness corresponding to the second medium and a second sudden change line of brightness corresponding to the liquid to be tested are formed in the detection image, the method It also includes: calculating the refractive index of the liquid to be tested according to the position of the second sudden change in brightness, and correcting the refractive index of the liquid to be tested according to the position of the first sudden change in brightness.

In one example, the detection area and the second medium are respectively located in different areas on the same surface of the first medium, and the second light beam is incident from the first medium without passing through the second medium to the detection zone.

In an example, the reflective module further includes a third medium having a different refractive index from the second medium, which is different from that in which the detection area and the second medium are respectively located on the same surface of the first medium. area; the light beam also includes a third light beam, the third light beam is at least partially totally reflected when it is incident from the first medium to the third medium, and the detection image also forms a corresponding part of the third medium The third abrupt change boundary line of brightness: correcting the refractive index of the liquid to be measured according to the position of the abrupt change boundary line of brightness includes: The refractive index of the liquid to be measured is corrected.

In an example, the first medium includes a prism having a light incident surface, a light exit surface, and a detection surface, and the detection area and the second medium are respectively located on different regions of the detection surface; the method further includes : through the first light exit on the light exit surface, at least part of the light beam totally reflected by the second medium is allowed to enter the converging lens through the first light exit, and through the second light exit on the light exit surface The light outlet allows at least part of the light beams totally reflected by the liquid to be measured to enter the converging lens through the second light outlet. In one example, a light entrance is further provided on the light incident surface, and the first light beam and the second light beam are incident on the detection surface through the light entrance; wherein, the first light exit and the second light outlet are respectively located on two sides of the projection of the light inlet on the light exit surface, and do not overlap with the projection.

In one example, the first medium, the second medium, and the detection area are stacked, and the detection area is set on the side of the second medium facing away from the first medium, and the second light beam is sequentially through the first medium and the second medium.

In one example, the reflection module includes a prism having a light incident surface, a light exit surface and a detection surface, the detection area is located on the detection surface; and a cured film is sandwiched between the detection area and the detection surface A material layer and a light-transmitting glass layer, the light-transmitting glass layer is used to seal the material layer and the prism in the refractometer, and the detection area is located on the light-transmitting glass layer facing away from the material side of the layer.

In one example, the refractive index of the prism is greater than the refractive index of the material layer, and the refractive index of the material layer is greater than the refractive index of the transparent glass layer, when the refractive index of the liquid to be measured is smaller than the When the refractive index of the light-transmitting glass layer is used, at least three boundary lines with abrupt brightness changes are formed on the detection image; the first medium is the prism, and the second medium is the material layer; or, the first The medium is the material layer, and the second medium is the transparent glass layer.

In an example, the refractive index of the prism is greater than the refractive index of the material layer, the refractive index of the material layer is greater than the refractive index of the light-transmitting glass layer, and the photosensitive array avoids the The position where the totally reflected light beam is converged by the converging lens makes only two boundary lines with abrupt brightness changes formed on the detection image; the first medium is the material layer, and the second medium is the light-transmitting glass layer.

In one example, the refractive index of the prism is greater than the refractive index of the material layer, the refractive index of the material layer is less than or equal to the refractive index of the transparent glass layer, the first medium is the prism, and the The second medium is the material layer, or the refractive index of the prism is less than or equal to the refractive index of the material layer, and the refractive index of the material layer is greater than the refractive index of the transparent glass layer.

In one example, the cured material layer is a photocured coating, or a high temperature cured coating, or a naturally cured coating. In one example, the cured material layer is a light-cured shadowless adhesive layer. In one example, the cured material layer has a refractive index greater than 1.33 and not greater than 1.6, and the value of the refractive index varying with temperature is within -0.0003/deg C to 0.0003/deg C. In an example, the refractive index of the second medium is greater than 1.33 and not greater than 1.6, and the value of the change of the refractive index with temperature is within -0.0003/deg C to 0.0003/deg C.

In an example, the imaging of the received light beam by the photosensitive array to generate a detection image includes: generating a sequence of detection images, wherein at least some of the images in the sequence of detection images adopt different exposure parameters; or, the detection images At least part of the images in the sequence correspond to different luminous intensities of the light source modules.

In one example, the aperture of the light emitting surface of the light source module is the same as or less than 1/5 of the aperture of the light emitting surface of the converging module, or the aperture of the light emitting surface of the light source module is larger than the aperture of the light emitting surface. 2 times the light aperture of the convergence module mentioned above. In an example, the detection angle range of the photosensitive surface array covers the total reflection angle range of the convergence module. In one example, the full width at half maximum of the outgoing light of the light source module is less than 5 nm, or a narrow-band filter is arranged on the outgoing light path of the light source module, and the half-height of the outgoing light filtered by the narrow-band filter is The width is less than 5nm. In an example, a dodging sheet is arranged on the outgoing light path of the light source module. In one example, the emitted light of the light source module is in the green light band, and the photosensitive area array is a CMOS sensor with a Bell pattern of RGGB.

In an example, before determining the boundary line of a sudden change in brightness in the detection image according to the detection image, the method further includes: determining that an absolute value of a difference between the brightness of the detection image and a preset brightness is greater than a threshold. In an example, before determining the boundary line of abrupt brightness change in the detection image according to the detection image, the method further includes: performing noise filtering on the target pixel row according to at least part of the upper and lower pixel rows of the target pixel row in the detection image. In an example, the performing noise filtering on the target pixel row according to at least part of the upper and lower pixel rows of the target pixel row in the detection image includes: according to the pixel value of the target pixel row and the at least part of the pixel row The weighted average of the pixel values of is used as the noise-filtered pixel value of the target pixel row. In an example, before determining the boundary line of a sudden change in brightness in the detection image according to the detection image, it further includes: determining pixel rows affected by stray light in the detection image, wherein the pixel rows affected by stray light are not It is used to determine the refractive index of the medium on the side of the total reflection interface facing away from the light source module. In an example, the detection image is obtained by weighted summation of multiple frames of images acquired by the photosensitive array.

In an example, the method further includes: obtaining the temperature of the medium located outside the total reflection interface and the temperature of the total reflection interface; according to the pre-stored temperature of the medium to be measured, the temperature of the total reflection interface and the temperature The relationship model of the refractive index of the measured medium, and the obtained temperature of the medium outside the total reflection interface and the temperature of the total reflection interface are used to calculate the refractive index of the medium.

In an example, the method further includes: calculating the turbidity of the medium located outside the reflection module according to the detection image. In an example, the detection image includes a non-reflection area; calculating the turbidity of the medium outside the reflection module according to the detection image includes: acquiring the scattering brightness and/or the non-total reflection area in the non-reflection area Or the degree of fuzziness of the sudden change in brightness; wherein, the non-total reflection area in the non-reflection area corresponds to the area in the non-reflection area that is incident on the reflection module at an angle smaller than the total reflection angle and then enters the photosensitive surface array ; calculating the turbidity according to the scattering luminance of the non-total reflection area in the non-reflection area and/or the fuzziness of the boundary line of the sudden change in luminance.

In an example, the non-reflective area further includes a total reflective area located on one side of the non-total reflective area; the acquisition of the scattered brightness of the non-total reflective area in the non-reflective area includes: using the non-reflective The brightness of the total reflection area in the area is used as a reference value to calculate the scattering brightness of the non-reflection area and the non-total reflection area in the detection image. In an example, the calculating the turbidity according to the scattering brightness of the non-total reflection area in the non-reflection area and/or the fuzzy degree of the sudden change boundary of the brightness includes: when the concentration of the liquid to be tested is lower than a preset Calculate the turbidity of the liquid to be tested according to the scattering brightness of the non-total reflection area on the non-reflection area in the detection image when the concentration is high; when the concentration of the liquid to be measured is higher than the preset concentration, according to the detection image The turbidity of the liquid to be tested is calculated based on the fuzzy degree of the sudden change boundary of the brightness.

In an example, the medium located outside the reflection module is the liquid to be tested; the method further includes: obtaining the volume of the liquid to be tested; calculating the volume to be tested according to the refractive index, turbidity and volume of the liquid to be tested Measure liquid calories. In an example, the medium located outside the reflective module is the liquid to be tested; the method further includes: using auxiliary equipment to obtain auxiliary information, wherein the auxiliary equipment includes a colorimeter, and the auxiliary information includes the liquid to be tested The color of the liquid; or, the auxiliary equipment includes an impedance meter, and the auxiliary information includes the ion content of the liquid to be tested; or, the auxiliary equipment includes a pH meter, and the auxiliary information includes the ion content of the liquid to be tested. Acidity value: determining the type of the liquid to be tested according to the auxiliary information and the refractive index and/or turbidity of the liquid to be tested.

In an example, before emitting the light beam to the reflection module in the refractometer, the method further includes: emitting liquid to clean the target object, and the medium outside the reflection module is the liquid after cleaning the target object; the method further includes : judging the cleanliness of the target object according to the refractive index of the liquid after cleaning the target object. In an example, the method further includes: judging whether to continue cleaning the target object according to the cleanliness of the target object.

In an example, before emitting the light beam to the reflection module in the refractometer, it further includes: fixing the refractometer on the inner wall of the pipeline; wherein the refractometer is used to measure the refraction of the flowing liquid in the pipeline rate, the sudden change boundary of brightness includes a sudden change boundary of brightness corresponding to the flowing liquid in the pipeline. Since the refractometer of the present application can be self-calibrated in real time, compared with the existing calculation refractometer that needs to be calibrated before measuring the liquid, the refractometer of the present application can obtain more accurate measurement results when measuring the flowing liquid in the pipeline.

Although the present invention has been particularly shown and described in conjunction with preferred embodiments, it will be understood by those skilled in the art that changes in form and details may be made to the present invention without departing from the spirit and scope of the invention as defined by the appended claims. Making various changes is within the protection scope of the present invention.

Claims

A refractometer, characterized in that it includes a light source module, a reflection module, a convergence module, a photosensitive array, a control module and a processor;

The control module is used to control the light beam emitted by the light source module;

The reflective module is used to receive the light beam from the light source module, when the light beam from the light source module satisfies the total reflection condition in the reflective module, the light beam is totally reflected in the reflective module and enters to the aggregation module;

The converging module is used for converging the light beam from the reflecting module onto the focal plane of the converging module;

The photosensitive surface array is located on the focal plane of the converging module, and the control module is also used to control the photosensitive surface array to detect the received light beam and output a detection image;

A processor, configured to determine a boundary line of a sudden brightness change in the detection image according to the detection image, and determine a refractive index corresponding to the sudden change boundary line of brightness according to a position of the sudden change boundary line of brightness.
The refractometer according to claim 1, wherein the reflection module comprises a first medium, and the refractometer further comprises a detection area arranged on the surface of the first medium; when the detection area covers the When measuring liquid, and the refractive index of the liquid to be measured is lower than the refractive index of the first medium, at least part of the light beam is totally reflected by the liquid to be measured;

The divergence angle of the light source module matches the detection area.
The refractometer according to claim 1, wherein the outgoing light beam of the light source module comprises a first light beam and a second light beam;

The reflection module includes a first medium and a second medium adjacently arranged, the refractive index of the first medium is greater than that of the second medium, and the first light beam is incident from the first medium to the a second medium and is at least partially totally reflected by said second medium,

The converging module is used to converge the totally reflected first light beam to the photosensitive surface array; the control module is also used to control the photosensitive surface array to detect the received first light beam and output a detection image ; The processor is configured to determine a first brightness mutation boundary line corresponding to the first light beam in the detection image;

Wherein, the refractometer further includes a detection area, which is arranged on the surface of one of the media in the reflection module, and is used to receive the second light beam;

When the detection area is covered with the liquid to be tested, and the refractive index of the liquid to be tested is lower than that of one of the mediums, at least part of the second light beam is totally reflected by the liquid to be tested; The converging module is also used for converging the totally reflected second light beam to the photosensitive surface array; the processor is also used for determining the second brightness abrupt change boundary line corresponding to the second light beam from the detection image, calculating the refractive index of the liquid to be tested according to the position of the second sudden change in brightness, and correcting the refractive index of the liquid to be tested according to the first sudden change in brightness.
The refractometer according to claim 3, wherein the detection area is arranged on the surface of the first medium, the detection area is used to receive the second light beam from the first medium; and the The detection area and the second medium are respectively located in different areas on the same surface of the first medium.
The refractometer according to claim 4, wherein the reflective module further comprises a third medium having a different refractive index from the second medium, and the detection area and the second medium are respectively located in the Different regions on the same surface of the first medium, the third medium is used for at least partial total reflection of the light beam received from the light source module, and converged to the photosensitive surface array through the converging module , a corresponding third brightness abrupt boundary line is also formed in the detection image;

The processor is used for correcting the refractive index of the liquid to be tested according to the first sudden change boundary of brightness and/or the third sudden change of brightness.
The refractometer according to claim 4, wherein the first medium comprises a prism having a light incident surface, a light exit surface and a detection surface, and the detection area and the second medium are respectively located on the detection surface in different areas of the

The light exit surface is provided with a first light exit and a second light exit respectively corresponding to the second medium and the detection area, at least part of the light beam totally reflected by the second medium passes through the first light exit Incident to the converging lens, at least part of the light beams totally reflected by the liquid to be measured are incident to the converging lens through the second light outlet.
The refractometer according to claim 6, wherein a light entrance is further arranged on the light incident surface, and the first light beam and the second light beam are incident on the detection surface through the light entrance superior;

Wherein, the first light exit port and the second light exit port are respectively located on two sides of the projection of the light entry port on the light exit surface, and do not overlap with the projection.
The refractometer according to claim 3, wherein the first medium, the second medium, and the detection area are stacked, and the detection area is set at the point where the second medium faces away from the first A side of a medium for receiving a second light beam passing sequentially through said first medium and said second medium.
The refractometer according to claim 8, wherein the reflection module comprises a prism having a light incident surface, a light exit surface and a detection surface, the detection area is located on the detection surface, and the detection area and A cured material layer and a light-transmitting glass layer are sandwiched between the detection surfaces, and the light-transmitting glass layer is used to seal the material layer and the prism in the refractometer, and the detection area is located at the The side of the transparent glass layer facing away from the material layer.
The refractometer according to claim 9, wherein the refractive index of the prism is greater than the refractive index of the material layer, and the refractive index of the material layer is greater than the refractive index of the transparent glass layer, when the When the refractive index of the liquid to be measured is lower than the refractive index of the light-transmitting glass layer, at least three dividing lines of sudden brightness changes are formed on the detection image;

The first medium is the prism, and the second medium is the material layer; or, the first medium is the material layer, and the second medium is the transparent glass layer.
The refractometer according to claim 9, wherein the refractive index of the prism is greater than the refractive index of the material layer, the refractive index of the material layer is greater than the refractive index of the transparent glass layer, and the The photosensitive surface array avoids the position where the light beams totally reflected by the material layer are converged by the converging lens, so that two dividing lines with sudden changes in brightness are formed on the detection image;

The first medium is the material layer, and the second medium is the transparent glass layer.
The refractometer according to claim 9, wherein the refractive index of the prism is greater than the refractive index of the material layer, and the refractive index of the material layer is less than or equal to the refractive index of the transparent glass layer, so The first medium is the prism, the second medium is the material layer, or,

The refractive index of the prism is less than or equal to the refractive index of the material layer, and the refractive index of the material layer is greater than the refractive index of the transparent glass layer.
The refractometer according to claim 9, wherein the cured material layer is a photocured coating, or a high temperature cured coating, or a naturally cured coating.
The refractometer according to claim 9, wherein the cured material layer is a light-cured shadowless adhesive layer.
According to the refractometer according to claim 9, the refractive index of the transparent glass layer is greater than the maximum value of the refractive index measurement range of the refractometer.
The refractometer according to claim 3, wherein the refractive index of the second medium is greater than 1.33 and not greater than 1.6, and the value of the change of the refractive index with temperature is within -0.0003/deg C to 0.0003/deg C .
The refractometer according to claim 3, wherein the detection image includes opposite first edges and second edges, wherein the closer the boundary line of sudden brightness changes in the detection image is to the first edge, the corresponding refraction The higher the rate;

The first sudden change boundary line of brightness is located between the first edge in the detection image and the sudden change boundary line of brightness corresponding to the maximum refractive index in the refractive index measurement range of the refractometer.
The refractometer according to claim 3, wherein the photosensitive surface array is used to output a detection image sequence, and the exposure parameters of at least some images in the detection image sequence are different; or,

The light source modules respectively have different luminous intensities corresponding to at least part of the images in the detection image sequence.
The refractometer according to any one of claims 1-18, characterized in that, the diameter of the light-emitting surface of the light source module is the same as the light-passing diameter of the converging module or the difference is less than 1/ of the diameter of the light-emitting surface 5,

Alternatively, the aperture of the light emitting surface of the light source module is greater than twice the light aperture of the converging module.
The refractometer according to any one of claims 1-18, characterized in that, the detection angle range of the photosensitive surface array covers the total reflection angle range of the converging module.
The refractometer according to any one of claims 1-18, characterized in that, the FWHM of the outgoing light of the light source module is less than 5 nm, or, a narrow-band filter is arranged on the outgoing light path of the light source module, The full width at half maximum of the outgoing light filtered by the narrow-band filter is less than 5 nm.
The refractometer according to any one of claims 1-18, characterized in that a dodging sheet is arranged on the outgoing light path of the light source module.
The refractometer according to any one of claims 1-18, wherein the outgoing light of the light source module is in the green light band, and the photosensitive area array is a CMOS sensor with a Bell pattern of RGGB.
The refractometer according to any one of claims 1-18, wherein the processor is further configured to determine the threshold of the detection image before determining the boundary line of the sudden change in brightness in the detection image according to the detection image. The absolute value of the difference between the brightness and the preset brightness is greater than the threshold.
The refractometer according to any one of claims 1-18, wherein the processor is further configured to, before determining the boundary line of a sudden change in brightness in the detection image according to the detection image, according to the Perform noise filtering on the target pixel row at least part of the pixel rows above and below the target pixel row.
The refractometer according to claim 25, wherein the processor is configured to use the weighted average of the pixel values of the target pixel row and the pixel values of at least some of the pixel rows as the target pixel row for noise filtering After the pixel value.
The refractometer according to any one of claims 1-18, wherein the processor is further configured to determine the row of pixels affected by stray light in the detection image, wherein the pixels affected by stray light The row is not used to determine the refractive index of the medium on the side of the total reflection interface facing away from the light source module.
The refractometer according to claim 26, wherein the processor is further configured to determine the intensity of stray light in the detection image according to the brightness comparison results of multiple rows of pixel rows and/or the brightness comparison results of multiple frames of detection images. The affected pixel row.
The refractometer according to any one of claims 1-18, wherein the detection image is obtained by weighted summation of multiple frames of images acquired by the photosensitive surface array.
The refractometer according to any one of claims 1-18, wherein the processor is further configured to calculate, according to the detection image, the Turbidity.
The refractometer according to claim 30, wherein the detection image includes a non-reflection area, and the processor is configured to obtain the scattered brightness and/or the sudden change in brightness of a non-total reflection area in the non-reflection area the degree of fuzziness of the boundary line, and calculating the turbidity according to the scattered brightness of the non-total reflection region in the non-reflection region and/or the fuzziness degree of the boundary line of the sudden change in brightness;

Wherein, the non-total reflection area in the non-reflection area corresponds to the area in the non-reflection area that is incident on the total reflection interface at an angle smaller than the total reflection angle and then incident on the photosensitive array.
The refractometer according to claim 31, wherein the non-reflective area further includes a total reflection area located on one side of the non-total reflection area;

The processor is configured to use the brightness of the total reflection area in the non-reflection area as a reference value to calculate the scattering brightness of the non-total reflection area of the non-reflection area in the detection image.
The refractometer according to claim 31, wherein the processor is configured to use the scattering brightness of the non-total reflection area on the non-reflection area in the detection image when the concentration of the liquid to be measured is lower than the preset concentration The turbidity of the liquid to be tested is calculated, and the turbidity of the liquid to be tested is calculated according to the degree of fuzziness of the boundary line of sudden brightness changes on the detection image when the concentration of the liquid to be tested is higher than a preset concentration.
The refractometer according to any one of claims 1-18, wherein the refractometer has a standby mode;

In the standby mode, the control module is in a dormant standby state, and the light source module and the photosensitive array are in a power-off state.
The refractometer according to any one of claims 1-18, wherein the refractometer has a low power consumption mode,

In the low power consumption mode, the control module is used to control the light source module and the photosensitive array to flash synchronously.
The refractometer according to claim 35, wherein the control module is configured to synchronously trigger a pulse width modulation signal to control the light source module according to the frame signal of the photosensitive array.
The refractometer according to any one of claims 1-18, wherein the control module is also used to obtain brightness information of the current environment, and adjust the detection image quality of the photosensitive surface array according to the brightness information .
The refractometer according to claim 37, wherein the control module is used to adjust the detection image quality of the photosensitive surface array by adjusting at least one of the following:

The emitted light intensity of the light source module, the exposure time of the photosensitive array, the analog gain of the photosensitive array, and the digital gain of the photosensitive array.
The refractometer according to any one of claims 1-18, characterized in that the refractometer further comprises a first temperature sensor and a second temperature sensor, and the first temperature sensor is arranged inside the reflective module or on the reflective module The surface is located on the area outside the optical path, and is used to detect the temperature of the reflection module; the second temperature sensor is arranged on the surface of the reflection module facing the liquid to be measured, and is used to detect the temperature of the liquid to be measured ;

The temperature of the liquid to be measured, the relationship model between the temperature of the reflection module and the refractive index of the liquid to be measured are pre-stored in the processor, and the processor is also used to The obtained temperature and the relationship model are used to calculate the refractive index of the liquid to be measured.
The refractometer according to any one of claims 1-18, wherein the photosensitive area array is an area array CMOS image sensor.
A method for detecting a refractive index, comprising:

Sending a beam of light to the reflective module inside the refractometer;

converging the light beam at least totally reflected by the reflection module to the photosensitive array located on the focal plane of the converging module through the converging module;

Using the photosensitive array to image the received light beam to generate a detection image;

determining a boundary line of a sudden change in brightness in the detection image according to the detection image;

The refractive index of the medium corresponding to the sudden brightness change boundary is determined according to the position of the sudden brightness change boundary in the detection image.
The method according to claim 41, wherein the refractometer further comprises a detection area arranged on the surface of the first medium in the reflection module, when the detection area is covered with the liquid to be measured, and When the refractive index of the liquid to be measured is lower than that of the first medium, at least part of the light beam is totally reflected by the liquid to be measured;

There is only one boundary line corresponding to the sudden change in brightness of the refractive index of the liquid to be measured formed in the detection image.
The method according to claim 41, wherein the light beam includes a first light beam and a second light beam, and the reflective module includes a first medium and a second medium adjacently arranged, and the light beam of the first medium The refractive index is greater than the refractive index of the second medium, the first light beam is incident from the first medium to the second medium, and is at least partially totally reflected by the second medium;

The refractometer also includes a detection area, which is arranged on the surface of one of the media in the reflection module, and is used to receive the second light beam; when the detection area is covered with the liquid to be measured, and the liquid to be measured When the refractive index is lower than the refractive index of one of the mediums, at least part of the second light beam is totally reflected by the liquid to be tested; the detection image is formed with a first sudden change in brightness corresponding to the second medium the boundary line and the second brightness sudden change boundary line corresponding to the liquid to be tested,

The method also includes:

calculating the refractive index of the liquid to be tested according to the position of the second sudden change in brightness,

The refractive index of the liquid to be measured is corrected according to the position of the first brightness mutation boundary line.
The method according to claim 43, wherein the detection area and the second medium are respectively located in different areas on the same surface of the first medium, and the second light beam is transmitted from the first medium A medium is incident to the detection zone without passing through the second medium.
The method according to claim 44, characterized in that, the reflection module further comprises a third medium having a different refractive index from the second medium, and the detection area and the second medium are respectively located in the third medium. Different regions on the same surface of a medium;

The light beam also includes a third light beam, the third light beam is at least partially totally reflected when incident on the third medium from the first medium, and a third light corresponding to the third medium is also formed in the detection image. Luminance mutation boundary;

The correcting the refractive index of the liquid to be measured according to the position of the first brightness mutation boundary line includes:

The refractive index of the liquid to be tested is corrected according to the first sudden change in brightness boundary and/or the third sudden change in brightness.
The method according to claim 44, wherein the first medium comprises a prism having a light incident surface, a light exit surface and a detection surface, and the detection area and the second medium are respectively located on the sides of the detection surface. in different areas;

The method also includes:

The first light exit on the light exit surface allows at least part of the light beams totally reflected by the second medium to enter the converging lens through the first light exit,

The second light exit on the light exit surface allows at least part of the light beams totally reflected by the liquid to be measured to enter the converging lens through the second light exit.
According to the method according to claim 46, a light entrance is further provided on the light incident surface, and the first light beam and the second light beam are incident on the detection surface through the light entrance;

Wherein, the first light exit port and the second light exit port are respectively located on two sides of the projection of the light entry port on the light exit surface, and do not overlap with the projection.
The method according to claim 43, characterized in that, the first medium, the second medium and the detection area are stacked, and the detection area is set on the side where the second medium faces away from the first one side of the medium, and the second light beam passes through the first medium and the second medium in sequence.
The method according to claim 48, wherein the reflection module comprises a prism having a light incident surface, a light exit surface and a detection surface, the detection area is located on the detection surface; and the detection area and the A cured material layer and a light-transmitting glass layer are sandwiched between the detection surfaces, and the light-transmitting glass layer is used to seal the material layer and the prism in the refractometer, and the detection area is located in the The side of the light-transmitting glass layer facing away from the material layer.
The method according to claim 49, wherein the refractive index of the prism is greater than the refractive index of the material layer, and the refractive index of the material layer is greater than the refractive index of the transparent glass layer, when the When the refractive index of the liquid to be measured is smaller than the refractive index of the light-transmitting glass layer, at least three dividing lines of sudden brightness changes are formed on the detection image;

The first medium is the prism, and the second medium is the material layer; or, the first medium is the material layer, and the second medium is the transparent glass layer.
The method according to claim 49, wherein the refractive index of the prism is greater than the refractive index of the material layer, the refractive index of the material layer is greater than the refractive index of the light-transmitting glass layer, and the photosensitive The area array avoids the position where the light beams totally reflected by the material layer are converged by the converging lens, so that only two dividing lines with abrupt brightness changes are formed on the detection image;

The first medium is the material layer, and the second medium is the transparent glass layer.
The method according to claim 49, wherein the refractive index of the prism is greater than the refractive index of the material layer, the refractive index of the material layer is less than or equal to the refractive index of the transparent glass layer, and the The first medium is said prism and said second medium is said layer of material, or,

The refractive index of the prism is less than or equal to the refractive index of the material layer, and the refractive index of the material layer is greater than the refractive index of the transparent glass layer.
The method according to claim 49, wherein the cured material layer is a photocured coating, or a high temperature cured coating, or a naturally cured coating.
The method of claim 49, wherein the cured layer of material is a light-cured shadowless adhesive layer.
The method according to claim 49, the refractive index of the transparent glass layer is greater than the maximum value of the refractive index measurement range of the refractometer.
The method according to claim 43, characterized in that, the refractive index of the second medium is greater than 1.33 and not greater than 1.6, and the value of the change of the refractive index with temperature is within -0.0003/deg C to 0.0003/deg C.
The method according to claim 43, wherein the detection image includes a first edge and a second edge opposite to each other, and the corresponding refractive index of the boundary line of sudden brightness change in the detection image is closer to the first edge higher;

The first sudden change boundary line of brightness is located between the first edge in the detection image and the sudden change boundary line of brightness corresponding to the maximum refractive index in the refractive index measurement range of the refractometer.
The method according to claim 43, wherein the light beam is emitted by a light source module, and using the photosensitive array to image the received light beam to generate a detection image includes:

A sequence of detection images is generated, wherein at least some of the images in the sequence of detection images adopt different exposure parameters; or at least some of the images in the sequence of detection images correspond to different luminous intensities of the light source modules.
The method according to any one of claims 41-58, characterized in that the diameter of the light-emitting surface of the light source module is the same as the light-passing diameter of the converging module or the difference is less than 1/5 of the diameter of the light-emitting surface ,

Alternatively, the aperture of the light emitting surface of the light source module is greater than twice the light aperture of the converging module.
The method according to any one of claims 41-58, wherein the detection angle range of the photosensitive surface array covers the total reflection angle range of the converging module.
The method according to any one of claims 41-58, characterized in that, the FWHM of the outgoing light of the light source module is less than 5 nm, or, a narrow-band filter is arranged on the outgoing light path of the light source module, through The full width at half maximum of the outgoing light filtered by the narrow-band filter is less than 5 nm.
The method according to any one of claims 41-58, characterized in that a dodging sheet is arranged on the outgoing light path of the light source module.
The method according to any one of claims 41-58, wherein the emitted light of the light source module is in the green light band, and the photosensitive area array is a CMOS sensor with a Bell pattern of RGGB.
The method according to any one of claims 41-58, further comprising:

It is determined that the absolute value of the difference between the brightness of the detection image and the preset brightness is greater than a threshold.
The method according to any one of claims 41-58, further comprising:

Noise filtering is performed on the target pixel row according to at least part of the upper and lower pixel rows of the target pixel row in the detection image.
The method according to any one of claims 41-58, wherein the noise filtering of the target pixel row according to at least part of the upper and lower pixel rows of the target pixel row in the detection image includes:

A weighted average of the pixel values of the target pixel row and the pixel values of at least some of the pixel rows is used as the noise-filtered pixel value of the target pixel row.
The method according to any one of claims 41-58, further comprising:

determining rows of pixels in said probe image that are affected by stray light,

Wherein, the pixel rows affected by stray light are not used to determine the refractive index of the medium located on the side of the total reflection interface facing away from the light source module.
The method according to any one of claims 41-58, wherein the detection image is obtained by weighted summation of multiple frames of images acquired by the photosensitive area array.
The method according to any one of claims 41-58, wherein the method further comprises:

acquiring the temperature of the medium outside the total reflection interface and the temperature of the total reflection interface;

According to the pre-stored temperature of the medium to be measured, the relationship model between the temperature of the total reflection interface and the refractive index of the medium to be measured, and the acquired temperature of the medium outside the total reflection interface and the temperature of the total reflection interface Compute the refractive index of the medium.
The method according to any one of claims 41-58, further comprising:

The turbidity of the medium located outside the reflection module is calculated from the detection image.
The method of claim 70, wherein the probe image includes non-reflective regions;

Calculating the turbidity of the medium located outside the reflection module according to the detection image, including:

Obtaining the scattered luminance of the non-total reflection area in the non-reflection area and/or the blurring degree of the sudden change boundary of the brightness; After the reflection angle is incident on the reflection module, it is incident on the area of the photosensitive surface array;

The turbidity is calculated according to the scattering luminance of the non-total reflection area in the non-reflection area and/or the fuzziness of the boundary line of the sudden change in luminance.
The method according to claim 71, wherein the non-reflective area further comprises a total reflection area located on one side of the non-total reflection area;

The acquisition of the scattered brightness of the non-total reflection area in the non-reflection area includes:

The scattering brightness of the non-total reflection area of the non-reflection area in the detection image is calculated by using the brightness of the total reflection area in the non-reflection area as a reference value.
The method according to claim 71, wherein the calculating the turbidity according to the scattering brightness of the non-total reflection area in the non-reflection area and/or the fuzziness of the boundary line of the sudden change in brightness comprises:

calculating the turbidity of the liquid to be tested according to the scattering brightness of the non-total reflection area on the non-reflection area in the detection image when the concentration of the liquid to be tested is lower than the preset concentration;

When the concentration of the liquid to be tested is higher than a preset concentration, the turbidity of the liquid to be tested is calculated according to the fuzzy degree of the boundary line of sudden brightness change on the detection image.
The method according to claim 70, wherein the medium positioned outside the reflection module is the liquid to be measured; the method further comprises:

Obtain the volume of the liquid to be tested;

The calorie of the liquid to be tested is calculated according to the refractive index, turbidity and volume of the liquid to be tested.
The method according to claim 70, wherein the medium positioned outside the reflection module is the liquid to be measured; the method further comprises:

Use auxiliary equipment to obtain auxiliary information, wherein, the auxiliary equipment includes a colorimeter, and the auxiliary information includes the color of the liquid to be tested; or, the auxiliary equipment includes an impedance meter, and the auxiliary information includes the color of the liquid to be tested. The ion content of the liquid; or, the auxiliary equipment includes a pH meter, and the auxiliary information includes the acidity value of the liquid to be tested;

The type of the liquid to be tested is determined according to the auxiliary information and the refractive index and/or turbidity of the liquid to be tested.
The method according to any one of claims 41-58, characterized in that, before sending the light beam to the reflection module in the refractometer, it also includes:

The liquid is emitted to clean the target object, and the medium located outside the reflection module is the liquid after cleaning the target object;

The method also includes:

The cleanliness of the target object is judged according to the refractive index of the liquid after cleaning the target object.
The method according to claim 76, further comprising;

Whether to continue cleaning the target object is judged according to the cleanliness of the target object.
The method according to any one of claims 41-58, characterized in that before sending a light beam to the reflection module in the refractometer, it further comprises:

Fixing the refractometer in the inner wall of the pipeline or on the surface of the inner wall of the pipeline;

Wherein, the refractometer is used to measure the refractive index of the flowing liquid in the pipeline, and the sudden change boundary of brightness includes a sudden change boundary of brightness corresponding to the liquid flowing in the pipeline.
A detection device, characterized by comprising the refractometer according to any one of claims 1-40.
According to the detection device according to claim 79, characterized in that, the detection device is a smart cup, including a cup cover and a cup body; the refractometer is arranged at the cup cover or the bottom of the cup body for Detect the refractive index of the liquid in the cup; a thin film is arranged on the bottom of the cup, and a closed space is formed between the bottom of the cup; a micro-pressure sensor is provided in the closed space for The volume of the liquid in the cup is detected; a calculation module is also provided in the closed space for calculating the calorie of the liquid according to the volume and refractive index of the liquid.
According to the detection device according to claim 79, it is characterized in that, the detection device is an intelligent scale, including a scale body; the refractometer is arranged in the scale body, and the surface of the scale body is also provided with a liquid container area and a first display area, the refractometer is used to detect the refractive index of the liquid in the liquid accommodating area, and the first display area is used to display the refractive index of the liquid; the scale is also set There is a weighing area and a second display area for displaying the weight of an object on the weighing area.