Ultraviolet analyzer for detecting sports diet finished product

Abstract

The invention relates to an ultraviolet analyzer for detecting sports diet finished products, which is characterized in that a lower liquid level table and an upper liquid level table are arranged on a base unit, and a to-be-detected fluid sample forms a liquid bridge between the lower liquid level table and the upper liquid level table; the surface energy anchoring structure is used for forcibly limiting a solid-liquid contact line of a to-be-detected fluid sample in a preset optical path light passing area; the liquid bridge impedance feedback loop is used for forming a closed loop through a liquid bridge in the liquid bridge stretching process so as to monitor the equivalent complex impedance value of the liquid bridge in real time; in the process that the driving unit drives the lifting detection head to stretch the liquid bridge, the stretching speed of the driving unit is adjusted in real time according to the complex impedance change rate fed back by the impedance analysis module; and the optical fiber spectrum detection unit is triggered to carry out spectrum acquisition at a plurality of different stretching heights when the liquid bridge maintains a continuous state. According to the invention, high-precision detection can be realized without physical dilution, and continuous spectrum data under a group of optical program columns can be obtained through single sample loading.

Description

Technical Field

[0001] This application relates to the technical field of spectral analysis and detection, and in particular to an ultraviolet analyzer for detecting finished sports diet products. Background Technology

[0002] An ultraviolet (UV) analyzer is a scientific instrument that analyzes substances based on their absorption of UV light or the fluorescence produced by excitation. Its core technologies are mainly divided into two categories: UV absorption spectroscopy and fluorescence analysis. UV absorption spectroscopy is based on the Lambert-Beer law; when UV light passes through a sample, light of a specific wavelength is absorbed, and qualitative and quantitative analysis of the substance can be performed by measuring the absorbance. Fluorescence analysis, on the other hand, utilizes photoluminescence. When a substance is irradiated with UV light of a specific wavelength, it absorbs light energy and enters an excited state. Upon instantaneous de-excitation, it emits fluorescence with a longer wavelength, and analysis is performed by detecting the fluorescence characteristics.

[0003] In the field of sports nutrition product testing, ultraviolet (UV) analyzers are mainly used for analyzing nutritional components such as proteins, nucleotides, vitamins, hormones, and alkaloids. With the rapid development of sports nutrition science, sports nutrition products are evolving towards higher concentrations, functionalization, and more complex dosage forms. To meet the energy and nutritional needs of athletes under extreme conditions, the market has seen a surge in high-concentration whey protein drinks, high-osmotic-pressure energy gels, and sustained-release supplements rich in functional micelles. These products place extremely high demands on the quantitative detection accuracy of core components (such as proteins, caffeine, and preservatives) in production quality control and anti-doping screening.

[0004] However, due to the extremely high concentration of sports nutrition products (such as concentrated protein solutions), their direct absorbance often far exceeds the linear response range of the detector. Therefore, existing technologies require high-magnification (e.g., 100-1000 times) artificial dilution of the sample. However, this dilution operation introduces systematic errors during multiple pipetting and volume adjustment operations and can damage the microstructure. Although the measured spectral data can reflect the total chemical content, it loses crucial information about the true physicochemical state of the finished product (such as bioavailability and sustained-release performance), leading to a disconnect between the test results and the actual performance of the product. Summary of the Invention

[0005] To address the problem that existing technologies cannot safely, stably, and accurately detect high-concentration, high-viscosity sports diet products without damaging the original state of the sample, this application provides an ultraviolet analyzer for detecting sports diet products.

[0006] The ultraviolet analyzer for detecting finished sports diet products provided in this application adopts the following technical solution:

[0007] An ultraviolet analyzer for testing finished sports diet products includes a base unit, a lifting detection head that can be vertically displaced relative to the base unit, a drive unit, a fiber optic spectroscopy detection unit, and a main control unit. The base unit is provided with a lower liquid level stage, and the lifting detection head is provided with an upper liquid level stage that is coaxially aligned with the lower liquid level stage. The fluid sample to be tested forms a liquid bridge between the two.

[0008] Also includes:

[0009] The surface energy anchoring structure is located on the opposite end faces of the upper liquid level stage and the lower liquid level stage, respectively, and is used to forcibly limit the solid-liquid contact line of the fluid sample to be tested within a preset optical path transmission area.

[0010] The liquid bridge impedance feedback loop has an upper liquid level platform and a lower liquid level platform made of conductive material or with a conductive coating on their surface, and is connected to an impedance analysis module. It is used to form a closed loop through the liquid bridge during the stretching process to monitor the equivalent complex impedance value of the liquid bridge in real time.

[0011] The main control unit is configured to execute dynamic optical path scanning logic: during the process of the drive unit driving the lifting detection head to stretch the liquid bridge, the stretching speed of the drive unit is adjusted in real time according to the complex impedance change rate fed back by the impedance analysis module, and the fiber optic spectral detection unit is triggered to perform spectral acquisition at multiple different stretching heights while the liquid bridge is in a continuous state.

[0012] Furthermore, the surface energy anchoring structure includes a hydrophilic light-transmitting area located in the central region of the upper liquid level platform and the lower liquid level platform, and a hydrophobic blocking ring surrounding the outer periphery of the hydrophilic light-transmitting area;

[0013] The diameter of the hydrophilic light-transmitting region is matched with the diameter of the incident light spot of the fiber optic spectral detection unit. The surface energy of the hydrophobic blocking ring is lower than a preset threshold, so that the end face contact area of ​​the fluid sample under test remains consistent with the hydrophilic light-transmitting region during the stretching process, without radial shrinkage or diffusion.

[0014] Furthermore, a pneumatically stabilizing nozzle is coaxially sleeved on the outside of the lifting detection head. The outlet end face of the pneumatically stabilizing nozzle is higher than the end face of the upper liquid level platform, and an annular airflow channel is formed between the pneumatically stabilizing nozzle and the upper liquid level platform.

[0015] The main control unit is connected to an airflow control unit, which is used to introduce laminar gas into the annular outlet airflow channel and can form a coaxial laminar gas sheath on the outer periphery of the liquid bridge during the liquid bridge stretching process.

[0016] The flow rate of the laminar gas sheath is configured to generate Bernoulli negative pressure or radial support pressure on the surface of the liquid bridge to counteract the necking effect caused by the stretching of the liquid bridge.

[0017] Furthermore, the main control unit also includes a microenvironment compensation module, and the airflow control unit is connected to a solvent saturation generator;

[0018] The microenvironment compensation module is configured to control the airflow control unit to spray gas containing saturated vapor of the matrix solvent according to the matrix type of the fluid sample to be tested, thereby constructing a zero mass transfer boundary layer within the laminar gas sheath that suppresses solvent evaporation from the surface of the sample to be tested.

[0019] Furthermore, the main control unit calculates the first derivative of the complex impedance value of the liquid bridge in real time. When the first derivative is detected to exceed the preset necking threshold, it determines that the liquid bridge is about to break and immediately controls the drive unit to stop stretching and maintain the current height. At the same time, it triggers the fiber optic spectral detection unit to perform the last limit optical path spectral acquisition. Then, it controls the drive unit to move in the opposite direction to compress the liquid bridge and restore its shape.

[0020] Furthermore, the main control unit also calculates the second derivative of the complex impedance value of the liquid bridge in real time. Only when the second derivative is greater than zero and the first derivative exceeds the preset necking threshold, it determines that the liquid bridge is about to break and immediately controls the drive unit to stop. If only the second derivative is greater than zero, the drive unit is preferentially controlled to reduce the stretching speed.

[0021] Furthermore, the impedance analysis module calculates the complex impedance value of the liquid bridge using the following formula:

[0022] Formula 1;

[0023] In the formula: This represents the complex impedance value of the liquid bridge;

[0024] The resistance of the liquid bridge solution;

[0025] For imaginary numbers, satisfying ;

[0026] Let be the angular frequency of the excitation signal, and , Values ​​range from 10kHz to 100kHz;

[0027] This represents the total capacitance of the system.

[0028] Furthermore, in Formula 1,

[0029] Formula 2;

[0030] In the formula: The resistivity of the fluid sample to be tested;

[0031] This is the current tensile length of the liquid bridge;

[0032] For different positions of the liquid bridge along the axial direction The cross-sectional area at that location.

[0033] Furthermore, when the main control unit predicts the critical fracture of the liquid bridge, it mainly relies on... The rate of change over time is used to make a judgment.

[0034] Furthermore, a piezoelectric ceramic transducer is connected between the upper liquid level stage and the lifting detection head. The main control unit is also configured to: before spectral detection, control the piezoelectric ceramic transducer to generate micron-level high-frequency vibrations, and use the surface energy anchoring structure as a boundary to generate micro-mixing eddies in the hydrophilic light-transmitting area of ​​the fluid sample to be tested, so as to remove tiny bubbles attached to the surface of the hydrophilic light-transmitting area.

[0035] In summary, the beneficial technical effects of this application are as follows:

[0036] 1. Achieve dynamically adjustable optical path: By stretching the liquid bridge, the thickness (optical path) of the fluid sample to be tested in the optical path can be continuously and automatically changed. For high-concentration samples, the main control unit can automatically or according to feedback stretch them to a longer optical path (thinner liquid column), which is equivalent to "optical dilution". The absorbance can be adjusted to the optimal detection range without physical dilution.

[0037] 2. An open liquid bridge detection area is adopted, in which the fluid sample to be tested is detected in a liquid bridge without solid sidewall constraints. The upper and lower liquid level stages only have point contact with the fluid sample to be tested. The fluid sample to be tested does not need to be injected into a closed space, which completely avoids the problems of sample loading difficulties and pool wall adhesion. Moreover, after the test, the stage can be cleaned by simply wiping, which is especially suitable for viscous samples.

[0038] 3. Minimize sample pretreatment interference. The shearing action of the fluid sample to be tested during the formation and stretching of the liquid bridge is relatively mild and controllable. The surface energy anchoring structure fixes the contact surface between the liquid bridge and the upper / lower liquid level stage, making the liquid bridge shape more controllable and repeatable. Then, the main control unit maintains the stability of the liquid bridge through impedance feedback, which can maintain the detection state with minimal mechanical disturbance.

[0039] 4. Integrating intelligent feedback and adaptive scanning, the spectral acquisition and liquid bridge impedance monitoring are coupled in a closed loop. The main control unit can automatically adjust the stretching strategy according to the real-time impedance signal (reflecting the health of the liquid bridge) and continuously acquire spectra under multiple different stable states. A set of continuous spectral data under a single sample loading can be obtained, which is richer in information and can intelligently capture extreme state data. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application;

[0041] Figure 2 yes Figure 1 A magnified view of part A in the middle;

[0042] Figure 3 This is a logic control diagram of the main control unit in an embodiment of this application.

[0043] Explanation of reference numerals in the attached figures:

[0044] 1. Base unit; 11. Lifting detection head; 12. Drive unit; 13. Fiber optic spectral detection unit;

[0045] 21. Lower liquid level platform; 22. Upper liquid level platform;

[0046] 3. Liquid bridge;

[0047] 41. Hydrophilic and translucent area; 42. Hydrophobic blocking ring;

[0048] 5. Pneumatically stabilized nozzle;

[0049] 6. Piezoelectric ceramic transducer. Detailed Implementation

[0050] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0051] This application discloses an ultraviolet analyzer for detecting finished sports diet products. (Refer to...) Figure 1 - Figure 3 It includes a base unit 1, a lifting detection head 11 that can be vertically displaced relative to the base unit 1, a drive unit 12, a fiber optic spectral detection unit 13, and a main control unit. The drive unit 12 is used to drive the lifting detection head 11 to move up and down above the base unit 1 with micrometer-level precision. Among them, the drive unit 12 and the fiber optic spectral detection unit 13 are existing technologies, which can be fully implemented by those skilled in the art, and need not be elaborated.

[0052] Reference Figure 1 and Figure 2 The base unit 1 is provided with a lower liquid level platform 21, and the lifting detection head 11 is provided with an upper liquid level platform 22 that is coaxially aligned with the lower liquid level platform 21. The fluid sample to be tested can form a liquid bridge 3 between the two.

[0053] The ultraviolet analyzer also includes:

[0054] The surface energy anchoring structure is located on the opposite end faces of the upper liquid level stage 22 and the lower liquid level stage 21, respectively, and is used to forcibly limit the solid-liquid contact line of the fluid sample to be tested within the preset optical path transmission area.

[0055] The liquid bridge 3 impedance feedback loop, with the upper liquid level stage 22 and the lower liquid level stage 21 both made of conductive material or having conductive coatings on their surfaces, is connected to the impedance analysis module. This loop forms a closed circuit through the liquid bridge 3 during the stretching process, allowing for real-time monitoring of the equivalent complex impedance value of the liquid bridge 3. Specifically, the lower liquid level stage 21 and the upper liquid level stage 22 are made of quartz glass, and their opposing surfaces are coated with transparent conductive coatings, such as ITO (indium tin oxide) films. The optical path of the fiber optic spectroscopy detection unit 13 passes through the lower liquid level stage 21, the liquid bridge 3, and the upper liquid level stage 22 sequentially from bottom to top. When the liquid bridge 3 is formed, the fluid sample itself acts as an electrolyte, forming a closed conductive circuit together with the conductive coatings of the lower and upper liquid level stages 21 and 22. The impedance analysis module applies a weak AC excitation signal to this circuit at a specific frequency and monitors the equivalent complex impedance value of the liquid bridge 3 in real time.

[0056] Reference Figure 1 , Figure 2 and Figure 3 The main control unit is configured to execute dynamic optical path scanning logic: during the process of the drive unit 12 driving the lifting detection head 11 to stretch the liquid bridge 3, the stretching speed of the drive unit 12 is adjusted in real time according to the complex impedance change rate fed back by the impedance analysis module, and the fiber optic spectral detection unit 13 is triggered to perform spectral acquisition under multiple different stretching heights when the liquid bridge 3 maintains a continuous state.

[0057] Specifically, the main control unit calculates the first derivative of the complex impedance value of the liquid bridge 3 in real time. When the first derivative is detected to exceed the preset necking threshold, the main control unit determines that the liquid bridge 3 is about to break and immediately controls the drive unit 12 to stop stretching and maintain the current height. At the same time, it triggers the fiber optic spectral detection unit 13 to perform the last limit optical path spectral acquisition. Then, it controls the drive unit 12 to move in the opposite direction to compress the liquid bridge 3 and restore its shape.

[0058] Furthermore, to further improve the prediction accuracy of the main control unit, the main control unit also calculates the second derivative of the complex impedance value of the liquid bridge 3 in real time. Only when the second derivative is greater than zero and the first derivative exceeds the preset necking threshold, the main control unit determines that the liquid bridge 3 is about to break and immediately controls the drive unit 12 to stop. If only the second derivative is greater than zero, the drive unit 12 is controlled to reduce the stretching speed.

[0059] In a typical application example, the impedance analysis module uses the following formula to calculate the complex impedance value of liquid bridge 3:

[0060] Formula 1;

[0061] In the formula: This is the complex impedance value of liquid bridge 3;

[0062] The resistance of the solution in liquid bridge 3;

[0063] For imaginary numbers, satisfying ;

[0064] Let be the angular frequency of the excitation signal, and , Values ​​range from 10kHz to 100kHz;

[0065] This represents the total capacitance of the system.

[0066] And in Formula 1,

[0067] Formula 2;

[0068] In the formula: The resistivity of the fluid sample to be tested;

[0069] This represents the current stretch length of liquid bridge 3;

[0070] For different positions of liquid bridge 3 along the axial direction The cross-sectional area at that location.

[0071] The impedance analysis module can specifically include an excitation source that generates a weak AC signal (e.g., 1kHz to 100kHz, voltage <1V), a sampling circuit, and a signal processing unit. For sports diet products (typically containing water, sugar, protein, and salt), the resulting liquid bridge 3 can be equivalently represented as a model of a resistor and capacitor connected in parallel / series.

[0072] During the stable stretching phase, the liquid bridge 3 is an approximately cylindrical shape, and as the drive unit 12 stretches at a constant speed... linearly increasing, The complex impedance value decreases linearly. The change over time is a gradual increase, i.e., the first derivative of the complex impedance value. It is a relatively small positive value. However, during the critical fracture stage of liquid bridge 3, when the tension exceeds the limit, the middle of liquid bridge 3 will instantly narrow, at which point the minimum cross-sectional area of ​​liquid bridge 3... It approaches 0 in an extremely short time, which means the complex impedance value The first derivative of the complex impedance value will increase rapidly in the instant before the liquid bridge 3 breaks. A huge spike suddenly appeared. Therefore, once the main control unit calculates and identifies this spike (neck constriction threshold), it means that the liquid bridge 3 is about to break and an immediate shutdown strategy is required.

[0073] Correspondingly, the first derivative of the complex impedance value Before reaching the necking threshold, the impedance curve has gradually changed from linear growth to exponential growth; and when the second derivative of the complex impedance value... This means the complex impedance value is increasing at an "accelerated" rate, marking the inflection point where liquid bridge 3 transitions from a "steady rheological state" to a "plastic necking state." Using the second derivative, this can be detected at the very beginning of necking, reacting much faster than the first derivative. Furthermore, some mechanical vibrations during the detection process may cause... The value jumps instantaneously (generating a large first derivative), but this jump usually does not have sustained acceleration (the second derivative is 0 or negative). Therefore, introducing the second derivative can filter out false signals. Thus, when the main control unit calculates and identifies that the second derivative is greater than zero, it can control the drive unit 12 to reduce the stretching speed; only when the first derivative reaches the necking threshold and the second derivative is greater than zero, the main control unit controls the drive unit 12 to stop immediately.

[0074] Therefore, when testing the fluid sample, a set amount of the fluid sample is first dropped onto the lower liquid level stage 21. Then, the drive unit 12 controls the lifting detection head 11 to move down, so that the lower end face of the upper liquid level stage 22 contacts the fluid sample and applies a slight pre-pressure to ensure good contact. Subsequently, the drive unit 12 begins to slowly lift the lifting detection head 11 at the initial speed, stretching the liquid bridge 3.

[0075] During this process, the impedance analysis module continuously sends complex impedance data to the main control unit. The main control unit calculates the first derivative of the complex impedance value (i.e., the rate of impedance change) in real time. When the absolute value of the first derivative of the complex impedance value begins to increase, it indicates that the liquid bridge 3 begins to neck and the impedance change accelerates. At this time, the main control unit will dynamically reduce the stretching speed of the drive unit 12 to pass through the unstable necking region in a "slow and fine-tuned" manner. Conversely, when the impedance change is stable, a faster stretching speed can be used to improve detection efficiency. Under multiple preset stretching heights (i.e., different optical paths) where the liquid bridge 3 maintains a continuous state, the main control unit sends a trigger signal to the fiber optic spectral detection unit 13 to collect the ultraviolet absorption spectrum under the current optical path. This is equivalent to automatically obtaining a continuous spectral dataset from short optical path (applicable to high concentration) to long optical path (applicable to low concentration) in one detection.

[0076] When the main control unit detects that the first derivative of the complex impedance value exceeds the preset necking threshold and the second derivative is greater than zero, it indicates that the impedance of liquid bridge 3 is changing rapidly and the risk of breakage is extremely high. The main control unit will immediately determine that liquid bridge 3 is about to break. Subsequently, it will perform three operations in sequence: control the drive unit 12 to stop abruptly and maintain the current height; trigger the fiber optic spectral detection unit 13 to perform a final spectral acquisition at the limit optical path; control the drive unit 12 to move in the opposite direction, compressing liquid bridge 3 to restore it to its initial shape for the next detection or sample recovery. This allows the liquid bridge 3 to be reset before it breaks and the aforementioned steps to be repeated for a second inspection, further improving the accuracy of the final detection results; or it can adjust the detection progress in time to avoid sample splashing, data loss, or even instrument contamination caused by the sudden breakage of liquid bridge 3.

[0077] Therefore, by forming a dynamically variable liquid bridge 3 optical path between the lower liquid level stage 21 and the upper liquid level stage 22, the step of artificially diluting high-concentration samples, which is necessary in traditional detection techniques, is avoided. This allows the original microstructures that determine the functionality of the product, such as protein micelles and polysaccharide networks, to be completely preserved. The detection results truly reflect the actual state of the finished product, which is of revolutionary significance for guiding the development of sports diet formulations.

[0078] However, considering the simplicity and efficiency of the digital signal processor within the main control unit in executing the critical fracture prediction mechanism for the liquid bridge 3, in a specific embodiment, the main control unit primarily relies on... The rate of change over time is used to determine this, as can be seen from Formula 2. Minimum cross-sectional area of ​​liquid bridge 3 It is inversely proportional to the shape of the liquid bridge 3 and is most sensitive to changes in the shape of the liquid bridge 3, which means it can accurately reflect the state of the liquid bridge 3's shrinkage / fracture.

[0079] In addition, to ensure the stability of the sample liquid bridge 3 formed between the upper liquid level stage 22 and the lower liquid level stage 21 during the detection process, so as to ensure the accuracy of the detection results.

[0080] In one feasible embodiment, refer to Figure 1 and Figure 2 The surface energy anchoring structure includes a hydrophilic light-transmitting area 41 located in the central region of the upper liquid level platform 22 and the lower liquid level platform 21, and a hydrophobic blocking ring 42 surrounding the outer periphery of the hydrophilic light-transmitting area 41.

[0081] The diameter of the hydrophilic light-transmitting region 41 matches the diameter of the incident light spot of the fiber optic spectral detection unit 13. The surface energy of the hydrophobic blocking ring 42 is lower than the preset threshold, so that the end face contact area of ​​the fluid sample under test remains consistent with the area of ​​the hydrophilic light-transmitting region 41 during the stretching process, and no radial shrinkage or diffusion occurs.

[0082] Specifically, the hydrophilic light-transmitting area 41 can be selected to have a diameter of 1 mm and is formed by plasma activation treatment of the quartz glass surface; while the hydrophobic blocking ring 42 is a Teflon coating or a micro-nano structure hydrophobic surface.

[0083] Thus, when detecting high-concentration, high-surface-tension syrups or protein solutions, the hydrophobic blocking ring 42 acts like an "invisible wall," forcibly locking the solid-liquid contact line of the test fluid sample droplet within the hydrophilic light-transmitting region 41. This improves the problem of radial contraction or slippage of the droplet bottom surface when stretching high-viscosity liquids in existing variable optical path devices, ensuring that the liquid bridge 3 between the upper liquid level stage 22 and the lower liquid level stage 21 is always approximately a perfect cylinder, thereby ensuring the geometric accuracy of the optical path calculation. This allows for high-precision detection without diluting the high-concentration test fluid sample.

[0084] In another feasible embodiment, refer to Figure 1 The lifting detection head 11 is also coaxially fitted with a pneumatic stabilizing nozzle 5. The outlet end face of the pneumatic stabilizing nozzle 5 is higher than the end face of the upper liquid level platform 22, and an annular airflow channel is formed between the pneumatic stabilizing nozzle 5 and the upper liquid level platform 22.

[0085] The main control unit is connected to an airflow control unit, which is used to introduce laminar gas into the annular outlet airflow channel. During the stretching process of the liquid bridge 3, a coaxial laminar gas sheath can be formed on the outer periphery of the liquid bridge 3.

[0086] The flow rate of the laminar gas sheath is configured to generate a Bernoulli negative pressure or radial support pressure on the surface of the liquid bridge 3 to counteract the necking effect caused by the stretching of the liquid bridge 3.

[0087] Furthermore, in other feasible embodiments, the main control unit further includes a microenvironment compensation module, and the airflow control unit is connected to a solvent saturation generator;

[0088] The microenvironment compensation module is configured to control the airflow control unit to spray gas containing saturated vapor of the matrix solvent according to the matrix type of the fluid sample to be tested. For example, saturated water vapor is used for water-based nutrient solutions, thereby constructing a zero mass transfer boundary layer in the laminar gas sheath that inhibits the evaporation of solvent on the surface of the sample to be tested.

[0089] Therefore, by forming a coaxial gas sheath around the stretched liquid bridge 3, lateral physical support can be provided for the liquid bridge 3, reducing the necking effect caused by stretching the liquid bridge 3 and thus maintaining the approximately cylindrical shape of the liquid bridge 3. Moreover, by mixing solvent saturated vapor into the coaxial gas sheath, a "same matrix microenvironment" can be constructed around the trace high-concentration sample. This avoids the problem of instantaneous evaporation and concentration caused by the dramatic increase in surface area when the trace original solution is stretched and thinned, ensuring that the detected concentration is the original concentration of the finished product, rather than the illusion of "concentration" during the test, thus ensuring the accuracy of the test results.

[0090] In addition, considering that finished sports diet products usually contain a certain amount of air bubbles, this will have a certain impact on the detection results of the fiber optic spectroscopy detection unit 13.

[0091] Therefore, referring to Figure 1 A piezoelectric ceramic transducer 6 is connected between the upper liquid level stage 22 and the lifting detection head 11. The main control unit is also configured to: before spectral detection, control the piezoelectric ceramic transducer 6 to generate micron-level high-frequency vibration, use the surface energy anchoring structure as a boundary, so that the fluid sample to be tested generates micro-mixing eddies in the hydrophilic light-transmitting area 41 to remove the tiny bubbles attached to the surface of the hydrophilic light-transmitting area 41, thereby eliminating the most common light scattering interference source in high-concentration viscous samples.

[0092] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," "third," and similar terms used in this application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. The terms "an" or "a" and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising" or "including" and similar terms mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, and do not exclude other elements or objects. "Above," "below," "left," "right," etc., are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0093] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A UV analyzer for detecting finished sports diet products, comprising a base unit, a lifting detection head that can be vertically displaced relative to the base unit, a drive unit, a fiber optic spectroscopy detection unit, and a main control unit, characterized in that, The base unit is provided with a lower liquid level platform, and the lifting detection head is provided with an upper liquid level platform that is coaxially aligned with the lower liquid level platform, and the fluid sample to be tested forms a liquid bridge between the two. Also includes: The surface energy anchoring structure is located on the opposite end faces of the upper liquid level stage and the lower liquid level stage, respectively, and is used to forcibly limit the solid-liquid contact line of the fluid sample to be tested within a preset optical path transmission area. The liquid bridge impedance feedback loop has an upper liquid level platform and a lower liquid level platform made of conductive material or with a conductive coating on their surface, and is connected to an impedance analysis module. It is used to form a closed loop through the liquid bridge during the stretching process to monitor the equivalent complex impedance value of the liquid bridge in real time. The main control unit is configured to execute dynamic optical path scanning logic: during the process of the drive unit driving the lifting detection head to stretch the liquid bridge, the stretching speed of the drive unit is adjusted in real time according to the complex impedance change rate fed back by the impedance analysis module, and the fiber optic spectral detection unit is triggered to perform spectral acquisition at multiple different stretching heights while the liquid bridge is in a continuous state.

2. The ultraviolet analyzer for detecting finished sports diet products according to claim 1, characterized in that, The surface energy anchoring structure includes a hydrophilic light-transmitting area located in the central region of the upper liquid level platform and the lower liquid level platform, and a hydrophobic blocking ring surrounding the outer periphery of the hydrophilic light-transmitting area; The diameter of the hydrophilic light-transmitting region is matched with the diameter of the incident light spot of the fiber optic spectral detection unit. The surface energy of the hydrophobic blocking ring is lower than a preset threshold, so that the end face contact area of ​​the fluid sample under test remains consistent with the hydrophilic light-transmitting region during the stretching process, without radial shrinkage or diffusion.

3. The ultraviolet analyzer for detecting finished sports diet products according to claim 1, characterized in that, The lifting detection head is also coaxially fitted with a pneumatic stabilizing nozzle. The outlet end face of the pneumatic stabilizing nozzle is higher than the end face of the upper liquid level platform, and an annular airflow channel is formed between the pneumatic stabilizing nozzle and the upper liquid level platform. The main control unit is connected to an airflow control unit, which is used to introduce laminar gas into the annular outlet airflow channel and can form a coaxial laminar gas sheath on the outer periphery of the liquid bridge during the liquid bridge stretching process. The flow rate of the laminar gas sheath is configured to generate Bernoulli negative pressure or radial support pressure on the surface of the liquid bridge to counteract the necking effect caused by the stretching of the liquid bridge.

4. The ultraviolet analyzer for detecting finished sports diet products according to claim 3, characterized in that, The main control unit also includes a microenvironment compensation module, and the airflow control unit is connected to a solvent saturation generator; The microenvironment compensation module is configured to control the airflow control unit to spray gas containing saturated vapor of the matrix solvent according to the matrix type of the fluid sample to be tested, thereby constructing a zero mass transfer boundary layer within the laminar gas sheath that suppresses solvent evaporation from the surface of the sample to be tested.

5. A UV analyzer for detecting finished sports diet products according to any one of claims 1-4, characterized in that, The main control unit calculates the first derivative of the complex impedance value of the liquid bridge in real time. When the first derivative is detected to exceed the preset necking threshold, it determines that the liquid bridge is about to break and immediately controls the drive unit to stop stretching and maintain the current height. At the same time, it triggers the fiber optic spectral detection unit to perform the last limit optical path spectral acquisition. Then, it controls the drive unit to move in the opposite direction to compress the liquid bridge and restore its shape.

6. The ultraviolet analyzer for detecting finished sports diet products according to claim 5, characterized in that, The main control unit also calculates the second derivative of the complex impedance value of the liquid bridge in real time. Only when the second derivative is greater than zero and the first derivative exceeds the preset necking threshold, it determines that the liquid bridge is about to break and immediately controls the drive unit to stop. If only the second derivative is greater than zero, it prioritizes controlling the drive unit to reduce the stretching speed.

7. The ultraviolet analyzer for detecting finished sports diet products according to claim 5, characterized in that, The impedance analysis module calculates the complex impedance value of the liquid bridge using the following formula: Formula 1; In the formula: This represents the complex impedance value of the liquid bridge; The resistance of the liquid bridge solution; For imaginary numbers, satisfying ; Let be the angular frequency of the excitation signal, and , Values ​​range from 10kHz to 100kHz; This represents the total capacitance of the system.

8. The ultraviolet analyzer for detecting finished sports diet products according to claim 7, characterized in that, In Formula 1, Formula 2; In the formula: The resistivity of the fluid sample to be tested; This is the current tensile length of the liquid bridge; For different positions of the liquid bridge along the axial direction The cross-sectional area at that location.

9. The ultraviolet analyzer for detecting finished sports diet products according to claim 8, characterized in that, When the main control unit predicts the critical fracture of the liquid bridge, it mainly relies on... The rate of change over time is used to make a judgment.

10. The ultraviolet analyzer for detecting finished sports diet products according to claim 2, characterized in that, A piezoelectric ceramic transducer is connected between the upper liquid level stage and the lifting detection head. The main control unit is also configured to: before spectral detection, control the piezoelectric ceramic transducer to generate micron-level high-frequency vibration, and use the surface energy anchoring structure as a boundary to generate micro-mixing eddies in the hydrophilic light-transmitting area of ​​the fluid sample to be tested, so as to remove tiny bubbles attached to the surface of the hydrophilic light-transmitting area.

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