Viscosity measuring method and viscometer

Abstract

The invention relates to a viscosity measuring method. The method comprises the following steps: acquiring a calibration constant; determining a first position reference of an injection port for closed injection of the sample; determining a second position reference of the front end of the sample liquid column, and obtaining the height of the liquid column according to the second position reference; if the heights of the liquid columns are inconsistent after multiple times of sample injection, returning to correct the calibration constant again; if the heights of the liquid columns are consistent after multiple times of sample injection, the calibration constant is judged to be effective; and obtaining the flowing time of the first distance on the sample flowing path, and obtaining the kinematic viscosity according to the effective calibration constant and the flowing time. The invention also relates to a viscometer, which can realize accurate control of the height of the measured liquid column and ensure the consistency of the height measurement of the liquid column and the accuracy of the viscosity measurement result.

Description

Technical Field

[0001] The present invention belongs to the field of viscosity measurement, and particularly relates to a viscosity measurement method and a viscometer. Background Art

[0002] As is well known, viscosity is one of the most important physical properties of petroleum products. For marine heavy fuel oil, lubricant additives and various petroleum products, viscosity measurement has important significance in many aspects.

[0003] First, the evaluation of combustion performance is inaccurate. Viscosity directly affects the atomization quality of fuel oil. Excessive viscosity will lead to incomplete combustion, increasing carbon deposition and pollutant emissions, while too low viscosity may affect the lubrication of fuel pumps. Second, it affects the design of the transportation system. The pipeline size, heater power and pump selection of the ship fuel system need to be based on viscosity data, especially to ensure the fluidity of fuel in low-temperature environments.

[0004] The main methods for measuring petroleum viscosity include capillary kinematic viscosity method, rotational viscosity measurement method, falling ball viscosity determination method, vibrating viscometer, etc. Among them, the gravity-type glass capillary method in the capillary method is the most accurate method in the existing measurement methods and is also the most commonly used method. However, petroleum has high viscosity and is dark in color. When measuring this type of sample, it is difficult to control the liquid column height during the measurement process due to reasons such as color and viscosity, resulting in low repeatability of measurement data and low accuracy of measurement results. Summary of the Invention

[0005] To solve the above technical problems, the purpose of the present invention is to provide a viscosity measurement method and a viscometer, which can achieve precise control of the liquid column height, ensure the consistency of liquid column height measurement, and the accuracy of viscosity measurement results.

[0006] The technical solution of the present invention is as follows: A viscosity measurement method includes: obtaining a calibration constant; determining a first position reference for the injection port of the sample closed injection; determining a second position reference for the front end of the sample liquid column, and obtaining the liquid column height according to the second position reference; if the liquid column height is inconsistent after multiple sample injections, return to correct the calibration constant again; if the liquid column height is consistent after multiple sample injections, determine that the calibration constant is valid; obtaining the flow time of the first distance on the sample flow path, and obtaining the kinematic viscosity according to the valid calibration constant and the flow time.

[0007] Preferably, the preset position reference for the sample closed injection port includes: the sample path includes an oblique path and a horizontal path, the intersection position of the oblique path and the horizontal path is the turning position, and the end of the horizontal path far from the turning position is set as the first position reference; each time the viscosity of the sample is measured, the sample is injected into the sample path through the first position reference, and during the injection process, the sample path is closed.

[0008] Preferably, the second position reference for determining the front end of the sample liquid column, and obtaining the liquid column height according to the second position reference includes: setting one end of the horizontal path close to the turning position as the second position reference for stopping adding the sample. The sample path includes a vertical path, and the vertical path is sequentially connected to the inclined path and the horizontal path. The liquid column height is obtained by calculating the vertical distance between the second position reference and the end point of the vertical path.

[0009] Preferably, the horizontal path forms a small angle with the horizontal plane.

[0010] Preferably, obtaining the calibration constant includes: determining the known kinematic viscosity of the standard liquid as the first kinematic viscosity; selecting a section of the path on the vertical path as the second distance; recording the time for the standard liquid to flow through the second distance, and the time is the first standard time; calculating and obtaining the standard constant according to the second distance and the first standard time.

[0011] Preferably, obtaining the flow time of the first distance on the sample flow path includes: setting a buffer space on the sample vertical path; the flow time is obtained by calculating the time when the sample enters the buffer space and the time when the sample flows out of the buffer space.

[0012] A viscometer includes: a cross arm; an inclined arm, one end of the inclined arm is connected to the cross arm, and the connection position is a turning position, and a first measuring member is provided at the turning position, and the first measuring member is used to record the first height of the sample liquid column. An injection port is provided at one end of the cross arm far from the turning position; a vertical arm, one end of the vertical arm is connected to the other end of the inclined arm, and a second measuring member and a third measuring member are provided on the vertical arm, and the second measuring member and the third measuring member are used to measure the time for the sample to flow through; sample flow paths are provided inside the cross arm, the inclined arm and the vertical arm and are connected to each other, and a vertical small tube is provided inside the end of the cross arm.

[0013] Preferably, the angle between the center line of the cross arm and the horizontal line is a small acute angle.

[0014] Preferably, the injection port is in a sealed state during sample injection.

[0015] Preferably, a measuring bulb is provided between the second measuring member and the third measuring member on the vertical arm, and a buffer space is provided inside the measuring bulb.

[0016] Preferably, a reinforcing column is provided between one end of the cross arm close to the injection port and the connection position of the inclined arm and the vertical arm.

[0017] Preferably, a sample cup is provided at the upper end of the injection port.

[0018] The present invention provides a viscosity measurement method, including: obtaining a calibration constant; determining a first position reference for the injection port of the sample closed injection; determining a second position reference for the front end of the sample liquid column, and obtaining the liquid column height according to the second position reference; if the liquid column heights are inconsistent after multiple samplings, returning to correct the calibration constant again; if the liquid column heights are consistent after multiple samplings, determining that the calibration constant is valid; obtaining the flow time of the first distance on the sample flow path, and obtaining the kinematic viscosity according to the valid calibration constant and the flow time. The present invention also provides a viscometer. For the viscosity measurement method and viscometer provided by the present invention, the sample injection point is fixed each time, avoiding the sample wall attachment phenomenon generated at the cup mouth of the viscometer by the conventional sampling method. Compared with the conventional method of injecting the sample into the cup mouth of the viscometer, the present invention requires less sample, thus less cleaning reagent, faster cleaning speed, higher efficiency, lower test cost and more environmental protection. By determining the second position reference for the front end of the sample liquid column, the front end position of the liquid column can be directly controlled, realizing the precise control of the liquid column height. The liquid column height can be controlled at the second position reference each time the sample is injected, making the test result more accurate. Conventionally, fixed volume and fixed quantity are adopted. In the present application, the second position reference is used as the injection reference to achieve quantification and control the liquid column height, thereby realizing repeated reproducibility and high measurement accuracy. Therefore, a precision pipette is not required, and an ordinary plastic syringe can accurately inject the sample, greatly saving the equipment cost, realizing the precise control of the measurement liquid column height, ensuring the consistency of the liquid column height measurement, and the accuracy of the viscosity measurement result. Description of the Drawings

[0019] Figure 1 It is a flowchart of the viscosity measurement method provided by the present invention; Figure 2 It is a schematic structural diagram of the viscometer provided by the present invention; Figure 3 It is a comparison diagram of the experimental results of the viscometer provided by the present invention and the conventional viscometer.

[0020] Description of the Reference Numerals in the Drawings 1. Cross arm; 2. Inclined arm; 3. First measuring member; 4. Vertical arm; 5. Second measuring member; 6. Third measuring member; 7. Vertical small tube; 8. Measuring bulb; 9. Reinforcing column; 10. Sampling cup. Detailed Embodiments

[0021] In order to enable those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0022] In the description of the present invention, it should be understood that the terms "upper", "lower", etc. indicating the orientation or position relationship are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the components or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention.

[0023] In the prior art, it is impossible to measure the accurate viscosity, mainly due to the inconsistent liquid column height of each sample. The main reasons for this inconsistency are as follows: 1. Since the viscosity of the sample is too high and the sampling speed is too fast, the measurement starts before reaching the predetermined amount; 2. The liquid column height is too high or too low due to too much or too little predetermined amount; 3. The injection position of each sample is different. For example, injecting against the bottom and injecting against the middle of the cup wall are different. Due to different sample wall attachment areas, the sample loss is different, and the amount of sample entering the viscometer is also different, thus resulting in different liquid column heights; 4. When injecting a dark sample, the sample color is deep and it adheres to the wall seriously, which will cause the end of the sample to be invisible, making it impossible to determine whether the appropriate amount of sample has been injected and impossible to determine the liquid column height. It can be seen that for samples with high viscosity, dark color (such as black) and invisible ends, it is very difficult to control the liquid column height and impossible to inspect the liquid column height, resulting in the repeatability and reproducibility of the test data being much lower than the requirements of the corresponding standards and being basically inadmissible.

[0024] Figure 1 As shown, the present invention provides a viscosity measurement method, including: obtaining a calibration constant; determining a first position reference for closing the injection port of the sample injection; determining a second position reference for the front end of the sample liquid column, and obtaining the liquid column height according to the second position reference; if the liquid column heights are inconsistent after multiple sample injections, then return to re-correct the calibration constant; if the liquid column heights are consistent after multiple sample injections, then determine that the calibration constant is valid; obtaining the flow time of the first distance on the sample flow path, and obtaining the kinematic viscosity according to the valid calibration constant and the flow time.

[0025] In this application, first, a calibration constant is obtained to acquire the fixed height h1 required for the standard liquid test. Then, it enters the calibration attempt verification stage. Before the test, it is determined whether the calibration constant is accurate. Similarly, the standard liquid can be injected multiple times, and whether the height of each injection is consistent with h1. If the heights are consistent, it indicates that the standard constant is accurate and can be used as an error reference. If the heights are inconsistent, it means that the provided standard constant is inaccurate and the calibration constant needs to be corrected again to bring it within the error control range of the viscosity measurement method. Then, it enters the third step, the sample test stage. The sample is injected from the first position reference position of the injection port of the closed injection. When the sample gradually reaches the second position reference at the front end, it means that the sample has been filled. At this time, the height h2 of the sample liquid column can be obtained. The liquid column height is fixed at h2 for each sample test. By fixing the injection port for each sample test and ensuring that the liquid column height h2 of each test is consistent with the height h1 of the standard liquid, finally, a section of distance is selected on the flow path to count the flow time and calculate the kinematic viscosity.

[0026] In the technical solution provided by this application, there are the following technical advantages: 1. The filling point of each sample is fixed, avoiding the sample wall adhesion phenomenon at the cup mouth of the viscometer in the conventional injection method. Compared with the conventional method of injecting samples into the cup mouth of the viscometer, this invention requires less sample, thus less cleaning reagent, faster cleaning speed, higher efficiency, lower test cost and more environmental protection. 2. By determining the second position reference at the front end of the sample liquid column, the front end position of the liquid column can be directly controlled, achieving precise control of the liquid column height. The liquid column height can be controlled at the second position reference for each sample injection, making the test results more accurate. 3. Conventionally, fixed volume and fixed quantity are used. In this application, quantitative injection is achieved by using the second position reference as the filling reference to control the liquid column height, and then repeated reproduction is realized with high measurement accuracy. Therefore, there is no need for a precision pipette, and an ordinary plastic syringe can accurately inject samples, greatly saving equipment costs.

[0027] Another core improvement point of this application is that the calibration constant C will be verified. The calibration constant C is one of the core parameters for measuring kinematic viscosity by the capillary method. It reflects the influence of the geometric characteristics of the viscometer, such as the inner diameter, length of the capillary and the liquid column height on the flow time. In the technical solution of this application, the value of the calibration constant C can be determined through the experimental data of known standard liquids. To ensure the accuracy of the calibration constant, once the liquid column heights are inconsistent after injection, it indicates that the calibration constant error is relatively large, which may have a greater impact on the measurement results, and the calibration constant needs to be corrected again.

[0028] Among them, the position reference for presetting the sample closed injection port includes: the sample path includes an oblique path and a horizontal path, and the intersection position of the oblique path and the horizontal path is the turning position. One end of the horizontal path far from the turning position is set as the first position reference; each time the viscosity of the sample is measured, the sample is injected into the sample path through the first position reference, and during the injection process, the sample path is closed.

[0029] Each time of measurement, by aligning the syringe tip with the first position reference, it is ensured that the liquid column always injects the sample from the same position. During the injection process, the sample path, especially the horizontal path, will be closed to prevent sample leakage or external air from entering. When the syringe is inserted through the first position reference, its tip seals the main horizontal path entrance, thus forming a closed system. And through this dual positioning of the first position reference and the second position reference, the consistency of the liquid column height after each sample injection is ensured. Therefore, the technical solution provided by the present application, this dual positioning realizes the precise control of the liquid column height and avoids the errors caused by inconsistent liquid column heights in the traditional method. At the same time, the sample is directly injected from the first position reference (the end of the horizontal path), avoiding the phenomenon of the sample adhering to the cup wall in the traditional method, reducing the sample loss, lowering the test cost, and improving the test efficiency at the same time. And precisely controlling the liquid column height ensures the effectiveness of the calibration constant C. When the liquid column height is inconsistent, it can also recheck whether the calibration constant is reliable. These two measures improve the accuracy of the kinematic viscosity measurement, are particularly suitable for the measurement of samples with high viscosity, dark color or opacity, and solve the problem of the difficult-to-visualize liquid column end in the traditional method. At the same time, the technical solution of the present application also has strong operation convenience. The design of the first position reference simplifies the operation steps. Only by aligning the syringe tip with the first position reference can the sample injection be completed, and it also supports two modes of manual and automatic sample injection to meet the test requirements in different scenarios. Therefore, through measures such as defining the first position reference and the second position reference, combining the closed design of the sample path, and verifying the calibration constant, this technical solution obtains a sample liquid column with strong consistency. This design not only improves the measurement accuracy, but also reduces the sample loss and test cost, and is particularly suitable for samples with high viscosity, dark color or opacity. At the same time, it supports manual and automated operations and has a wide range of application prospects.

[0030] In the embodiment provided by the present invention, to determine the second position reference at the front end of the sample liquid column, and obtain the liquid column height according to the second position reference, the method includes: setting one end of the horizontal path close to the turning position as the second position reference for stopping adding the sample. The sample path includes a vertical path, and the vertical path is sequentially connected to the oblique path and the horizontal path. The liquid column height is obtained by calculating the vertical distance between the second position reference and the end point of the vertical path.

[0031] The sample path includes an oblique path, a transverse path, and a vertical path, which are connected in sequence. A second position reference is set at one end of the transverse path near the turning position. This reference is used to determine the end position of the liquid column, and the end of the vertical path serves as a reference point for calculating the liquid column height. The second position reference is equivalent to the height of the reference plane, and the difference between the height of the end of the vertical path relative to the same reference plane and the second position reference is the liquid column height. The second position reference can be set as a scale line or through a sensor. Therefore, through the definition of the second position reference (one end of the transverse path near the turning position) and in combination with the reference point at the end of the vertical path, the precise calculation of the liquid column height is achieved in this technical solution. This design not only reduces human error but is also particularly suitable for the measurement of samples with high viscosity, dark color, or opacity. At the same time, it supports both manual and automated operations, featuring high precision, high efficiency, and reliability, providing a new solution for the field of viscosity measurement.

[0032] Among them, the transverse path forms a small angle with the horizontal plane. The transverse path is designed to form a small angle (not completely horizontal) with the horizontal plane to ensure the smooth flow of the liquid under the action of gravity. This design with a small angle avoids the retention of the liquid in the cross-arm 1 and facilitates the complete discharge of the cleaning liquid. The design of the small angle of the transverse path in this technical solution enables the liquid to flow naturally under the action of gravity, avoiding the possible liquid retention phenomenon in the traditional horizontal path. This design allows the liquid to flow naturally under the action of gravity, avoiding the possible liquid retention phenomenon in the traditional horizontal path. The design with a small angle not only facilitates the flow of the sample but also facilitates the complete discharge of the cleaning liquid, reducing the possibility of liquid residue during the cleaning process, improving the cleaning efficiency, reducing the amount of cleaning reagent required, and reducing the test cost and environmental burden. The design with a small angle avoids the retention of the liquid in the cross-arm 1, ensuring the consistency of the liquid column height after each injection. This consistency improves the repeatability and reproducibility of the measurement results, thereby enhancing the overall measurement accuracy. Whether it is a low-viscosity or high-viscosity sample, the design with a small angle can ensure the smooth flow of the liquid. In the embodiments provided by the present invention, obtaining the calibration constant includes: determining the known kinematic viscosity of the standard liquid as the first kinematic viscosity; selecting a section of the path on the vertical path as the second distance; recording the time for the standard liquid to flow through the second distance, which is the first standard time; calculating the standard constant based on the second distance and the first standard time. By selecting a fixed second distance on the vertical path and accurately recording the time for the standard liquid to flow through this path in the present application, the error caused by the uncertainty of the path length can be reduced, and the calculated calibration constant is more accurate and reliable. This technical solution focuses the calibration process on the vertical path, avoiding the complexity of the need to comprehensively calibrate the entire sample path in the traditional method. Only by recording the time for the standard liquid to flow through the second distance can the calibration be completed, and the operation is simple and efficient. Moreover, by only adjusting the selection of the second distance and the choice of the standard liquid, the measurement requirements for different viscosity ranges can be adapted, which is especially suitable for the measurement of samples with high viscosity, dark color or opacity. These samples may be difficult to accurately control the liquid column height in the traditional calibration method. The fixity of the second distance and the accurate recording of the first standard time ensure the consistency of the conditions in each calibration process. This consistency improves the reliability of the calibration constant, thereby enhancing the repeatability and reproducibility of the subsequent measurement results. The first standard time can also be recorded by an automated control system, such as using a liquid level sensor, reducing the human observation error and improving the automation degree and accuracy of the measurement process.

[0033] Regarding the determination of the calibration constant, it should be noted that the calibration constant is determined according to the formula where C is the calibration constant, —capillary radius, g—acceleration due to gravity, h—liquid column height, V—volume of the sample flowing through the second distance, t—flow time, that is, the time for the sample to flow through the second distance, that is, the time to fill the volume V, L—capillary length, that is, the vertical distance between the second position reference on the cross arm 1 and the vertical path head office. It can be seen that the calibration constant depends on the inner diameter, length, acceleration due to gravity, liquid height and fluid volume of the capillary. For the same capillary, the inner diameter, length, acceleration due to gravity and fluid volume of the capillary have been determined. As long as the liquid column height remains unchanged, the calibration constant is determined. Therefore, when determining the calibration constant, it is also necessary to ensure that the end of the sample liquid column is also at the second position reference.

[0034] Preferably, obtaining the flow time of the first distance on the sample flow path includes: setting a buffer space on the vertical path of the sample; the flow time is calculated based on the time when the sample enters the buffer space and the time when the sample exits the buffer space.

[0035] In the embodiments provided by the present invention, a buffer space is designed on the vertical path of the sample. This space is located at a specific position in the flow path. The role of the buffer space is to temporarily hold part of the sample in order to accurately record the time when the sample enters and exits. When the sample flows into the vertical path from above, the time when the sample reaches the entrance of the buffer space is recorded through a liquid level sensor or other detection devices, denoted as the first time point t1. When the sample continues to flow and leaves the buffer space, the time when the sample completely exits the buffer space is recorded again through another liquid level sensor or other detection devices, denoted as the second time point. Finally, based on the time difference between the sample entering and exiting the buffer space, the flow time of the sample over the first distance is calculated. Thus, it can be seen that the design of the buffer space ensures the stability and controllability during the sample flow process. By separately recording the time when the sample enters and exits the buffer space, the flow time of the sample over the first distance can be calculated more accurately, reducing the time measurement errors caused by complex paths or sample characteristics. For samples with high viscosity, their flow rate is slow and they may get stuck in the path. The design of the buffer space can effectively alleviate these problems, ensuring the continuity and stability of the flow process, and is particularly suitable for the measurement of dark or opaque samples.

[0036] According to Figure 2 、 Figure 3 As shown, the present invention also provides a viscometer, including a cross arm 1; an inclined arm 2, one end of the inclined arm 2 is connected to the cross arm 1, and the connection position is a turning position, where a first measuring member 3 is provided at this turning position. The first measuring member 3 is used to record the first height of the sample liquid column. An injection port is provided at one end of the cross arm 1 far from the turning position; a vertical arm 4, one end of the vertical arm 4 is connected to the other end of the inclined arm 2, and a second measuring member 5 and a third measuring member 6 are provided on the vertical arm 4. The second measuring member 5 and the third measuring member 6 are used to measure the time taken for the sample to flow through. The sample flow paths are provided inside the cross arm 1, the inclined arm 2, and the vertical arm 4 and are all interconnected. A vertical small tube 7 is provided inside the end of the cross arm 1. Traditional bent viscometers usually adopt a simple bending design, while the viscometer of the present invention improves the measurement accuracy and operation convenience by optimizing the connection and shape of each part. The design of the cross arm 1 is mainly to ensure the smooth flow of the test sample and prevent the cleaning liquid from staying. A clear turning position is set at the connection position between the cross arm 1 and the inclined arm 2, and a first measuring member 3 is installed at this position to record the height of the sample liquid column (i.e., the position of the end of the liquid column). This design defines the control point of the liquid column height and avoids the errors caused by the uncertain position of the end of the liquid column in the traditional method.

[0037] The present invention has made functional improvements to each component of the viscometer to improve the measurement accuracy and efficiency. One end of the cross arm 1 is connected to the inclined arm 2 through a turning position, and the other end is provided with an injection port. The design of the injection port allows a disposable plastic syringe to be directly used to add samples to the end of the cross arm 1, thus completely avoiding the problem of inconsistent liquid column heights caused by sample wall adhesion in the conventional sample injection method. One end of the inclined arm 2 is connected to the cross arm 1, and the other end is connected to the vertical arm 4. The first measuring member 3 provided at the turning position can accurately record the height of the liquid column to ensure that the position of the end of the liquid column is consistent for each sample injection. The second measuring member 5 and the third measuring member 6 are provided on the vertical arm 4 to measure the time taken for the sample to flow through. These two measuring members can be capillary upper and lower sensors, which can accurately capture the time for the sample to flow from top to bottom. It should be noted that a very short vertical small tube 7 is provided at the end of the cross arm 1 (the junction of the lower end of the small tube and the cross arm 1 is called the end of the cross arm 1). The inner diameter of the vertical small tube 7 is adapted to the tip of the disposable plastic syringe, enabling sealed insertion. The tip of the syringe contacts or is very close to the cavity of the cross arm 1, ensuring that the position of the end of the liquid column is always fixed at the position of the tip of the syringe. The cross arm 1 and the inclined arm 2 are connected through a turning position, and the first measuring member 3 provided at the turning position can accurately record the height of the liquid column. This connection method ensures that there is no retention or backflow phenomenon when the sample enters the inclined arm 2. The inclined arm 2 and the vertical arm 4 are connected in a smooth transition manner to ensure that the sample can smoothly flow into the capillary part in the vertical arm 4. The sample flow path inside the vertical arm 4 is connected to the cross arm 1 and the inclined arm 2 to form a complete sample flow channel. Thus, it can be seen that through the above structural improvements in this application, the folding tube viscometer provided by the present invention not only improves the measurement accuracy but also expands its application range, especially when dealing with complex samples, it performs particularly outstandingly.

[0038] Among them, the included angle between the center line of the cross arm 1 and the horizontal line is a small acute angle. Such a design makes the inclined arm 2 have a certain slope, which can ensure that the sample can smoothly flow from the cross arm 1 into the capillary, avoiding measurement errors caused by liquid retention. During cleaning, the cleaning liquid can be smoothly discharged without staying at the cross arm 1. The slope design of the cross arm 1 makes the position of the end of the liquid column clearer, enabling precise positioning of the liquid column height, thus effectively solving the measurement error problem caused by inconsistent liquid column heights in the traditional method. Therefore, through the design of the slope of the cross arm 1 and the precise control of the liquid column height, this technical solution not only improves the measurement accuracy of the folding viscometer but also expands its application range, and at the same time shows significant advantages in operation efficiency and environmental protection.

[0039] Furthermore, the injection port is in a sealed state during sample injection. When the tip of a disposable plastic syringe is inserted into the small tube of the injection port, a tight seal is formed between the syringe tip and the small tube. This seal ensures that the sample does not leak during injection and that no air mixes into the flow path of the sample. This sealed state ensures that the sample does not leak from the injection port during injection, thus avoiding loss of sample volume and measurement errors, which is particularly important for samples with high viscosity, dark color, etc., where it is difficult to visually observe the end of the liquid column. If the injection port is not sealed, air may mix into the sample flow path, forming bubbles. The presence of bubbles will change the flow characteristics of the sample, resulting in inaccurate measurement results. The sealed state effectively prevents air from mixing in and ensures the continuity and stability of the sample flow. In the sealed state, the position of the syringe tip remains fixed, thus ensuring that the end of the liquid column is always located at a predetermined position. Therefore, keeping the injection port sealed during sample injection is a key design of the folded-tube viscometer of the present invention. It not only prevents sample leakage and air mixing but also ensures precise control of the liquid column height, thereby improving the measurement accuracy and reliability. This design is particularly suitable for measuring complex samples with high viscosity, dark color, etc., significantly expanding the application range of the viscometer, while enhancing the operation convenience and test efficiency.

[0040] In the embodiment provided by the present invention, a measuring bulb 8 is provided between the second measuring member 5 and the third measuring member 6 of the vertical arm 4. A buffer space is provided inside the measuring bulb 8. In the viscometer provided by the present invention, the measuring bulb 8 is a key component. It is located between the second measuring member 5 and the third measuring member 6 on the vertical arm 4 and is provided with a buffer space inside. This position arrangement ensures that the flow state of the sample can be accurately recorded when the sample flows through the measuring bulb 8. The measuring bulb 8 is internally designed with a buffer space for accommodating the pressure fluctuations generated by the sample during flow. The presence of the buffer space can reduce measurement errors caused by changes in the sample flow rate or pressure unevenness when the sample flows into the capillary. By providing the measuring bulb 8 with a buffer space on the vertical arm 4, the folded-tube viscometer of the present invention not only stabilizes the flow state of the sample but also significantly improves the measurement accuracy and applicable range. This design innovation, combined with the functional improvements of other components (such as the horizontal arm 1, the inclined arm 2, the injection port, etc.), together constitutes an efficient, accurate, and environmentally friendly viscosity measurement system, which is particularly suitable for handling the viscosity test requirements of complex samples.

[0041] Further, at one end of the cross arm 1 close to the injection port, a reinforcing column 9 is provided between the connection of the inclined arm 2 and the vertical arm 4. In the folding tube viscometer of the present invention, the reinforcing column 9 is an important auxiliary structure, which connects one end of the cross arm 1 close to the injection port with the connection of the inclined arm 2 and the vertical arm 4. This design ensures that the structure of the entire viscometer is more stable, facilitating installation and operation. The shape of the reinforcing column 9 can be adjusted according to actual needs, usually columnar or rod-shaped. The presence of the reinforcing column 9 does not affect the flow path of the sample and only serves as a structural support.

[0042] Wherein, a sample injection cup 10 is provided at the upper end of the injection port. The presence of the sample injection cup 10 provides a stable space for the insertion of the syringe, avoiding the deviation of the position of the end of the liquid column caused by the inclination or shaking of the syringe. This stability is crucial for accurately controlling the liquid column height, especially when dealing with complex samples such as high-viscosity and dark-colored samples.

[0043] As Figure 3 shown, the experimental comparison results of the viscometer provided by the present invention and a conventional viscometer are as follows. The specific experimental method is: in a 40 °C constant temperature bath, a high-viscosity silicone oil is used to compare the measurement results of a conventional folding viscometer and the quantitative viscometer involved in the present application, and the timing results of the bulb are used to represent. The conventional folding tube viscometer uses a pipette to inject samples from the cup mouth, and the quantitative viscometer uses a disposable syringe to insert into the cup mouth of the viscometer. It can be seen from the experimental results that: from the measurement results of the two different viscometers, the measurement repeatability of the quantitative viscometer involved in the present application is much better than that of the conventional folding tube viscometer.

[0044] It should be noted that the viscometers provided by the present invention can all be used by the above-mentioned viscometry method. Similarly, the viscometry method can also be implemented by using a viscometer. The two can be referred to each other and will not be elaborated here.

[0045] The embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts among the various embodiments can be referred to each other.

[0046] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A viscosity measurement method, characterized in that, Including: Obtain calibration constants; Determine the first position reference of the injection port for sample closed injection; Determine the second position reference of the front end of the sample liquid column, and obtain the liquid column height according to the second position reference; If the liquid column heights are inconsistent after multiple sample injections, return to re-correct the calibration constants; If the liquid column heights are consistent after multiple sample injections, determine that the calibration constants are valid; Obtain the flow time of the first distance on the sample flow path, and obtain the kinematic viscosity according to the valid calibration constants and the flow time.

2. The viscosity measurement method according to claim 1, characterized in that, The preset position reference of the sample closed injection port includes: The sample path includes an oblique path and a horizontal path, and the intersection position of the oblique path and the horizontal path is the turning position. The first position reference is set at one end of the horizontal path far from the turning position; Each time the viscosity of the sample is measured, the sample is injected into the sample path through the first position reference, and during the injection process, the sample path is closed.

3. The viscosity measurement method according to claim 2, wherein The determination of the second position reference of the front end of the sample liquid column, and obtaining the liquid column height according to the second position reference includes: Set the second position reference for stopping adding the sample at one end of the horizontal path close to the turning position, The sample path includes a vertical path, and the vertical path is successively connected to the oblique path and the horizontal path. The liquid column height is obtained by calculating the vertical distance between the second position reference and the end point of the vertical path.

4. The viscosity measurement method according to claim 3, characterized in that, The horizontal path forms a small angle with the horizontal plane.

5. The viscosity measurement method according to claim 4, wherein The obtaining of the calibration constants includes: Determine the known kinematic viscosity of the standard liquid as the first kinematic viscosity; Select a section of the path on the vertical path as the second distance; Record the time for the standard liquid to flow through the second distance, and the time is the first standard time; Calculate and obtain the standard constant according to the second distance and the first standard time.

6. The viscosity measurement method according to claim 5, characterized in that, The obtaining of the flow time of the first distance on the sample flow path includes: Set a buffer space on the sample vertical path; The flow time is obtained by calculating the time when the sample enters the buffer space and the time when the sample flows out of the buffer space.

7. A viscometer, characterized in that, Including: Cross arm (1); Oblique arm (2), one end of the oblique arm (2) is connected to the cross arm (1), and the connection position is the turning position. A first measuring member (3) is provided at the turning position, and the first measuring member (3) is used to record the first height of the sample liquid column. An injection port is provided at one end of the cross arm (1) far from the turning position; Vertical arm (4), one end of the vertical arm (4) is connected to the other end of the oblique arm (2). A second measuring member (5) and a third measuring member (6) are provided on the vertical arm (4), and the second measuring member (5) and the third measuring member (6) are used to measure the time for the sample to flow through; The cross arm (1), the oblique arm (2) and the vertical arm (4) are all provided with a connected sample flow path inside, and a vertical small tube (7) is provided inside the end of the cross arm (1).

8. The viscometer according to claim 7, characterized in that, The included angle between the center line of the cross arm (1) and the horizontal line is a small acute angle.

9. The viscometer according to claim 8, characterized in that, The injection port is in a sealed state during sample injection.

10. The viscometer according to claim 9, characterized in that, A measuring bulb (8) is provided between the second measuring member (5) and the third measuring member (6) on the vertical arm (4), and a buffer space is provided inside the measuring bulb (8).

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