Liquid surface tension measurement experimental instrument

Abstract

The utility model provides a liquid surface tension measurement experiment instrument which comprises a base and an electric box, a precise lifting fine adjustment device and a stand column are installed on the base, a glassware base is installed above the precise lifting fine adjustment device, a leveling level is connected to the glassware base, and a glassware is arranged on the glassware base. A limiting nut is installed at the top end of the stand column, a limiting ring is installed on the stand column, a sensor support is arranged between the limiting ring and the limiting nut, and a locking hand wheel is installed on the sensor support. A force sensor is installed at the front end of the left side of the sensor support and connected with a force sensor connecting line, the force sensor is covered with a protective outer cover, a force sensor hook is installed at the bottom of the protective outer cover, and a sample connecting filament is connected to the bottom of the force sensor hook. The utility model relates to the field of liquid surface tension measurement, and has the advantages of high precision and large lifting range by adopting precise lifting fine adjustment, so that the experiment operation is more convenient.

Description

Technical Field

[0001] The utility model relates to the field of liquid surface tension measurement, and particularly relates to an experimental instrument for measuring liquid surface tension. Background Art

[0002] In the existing college experimental environment, the measurement of liquid surface tension is one of the important basic experiments in the fields of chemistry, physics, materials science, etc. Currently, most of the experimental instruments for measuring liquid surface tension use a pneumatic method to achieve lifting, or a small-range lifting is carried out through a micro-adjustment device. However, these technical solutions have obvious disadvantages: the pneumatic method is easily affected by air pressure fluctuations and the operation is unstable; while the micro-lifting device cannot meet a wider range of experimental needs due to its limited adjustment range. In addition, these devices are usually not convenient enough during operation, which affects the experimental efficiency and measurement accuracy. Summary of the Invention

[0003] In view of this, the utility model aims to provide an experimental instrument for measuring liquid surface tension to solve the problems of low processing accuracy and small lifting range.

[0004] To achieve the above object, the technical solution of the utility model is realized as follows:

[0005] An experimental instrument for measuring liquid surface tension includes a base, a weight pan, weights, and an electric box. The bottom of the base is equipped with leveling feet. On the left and right sides of the base, a precision lifting micro-adjustment and a column are respectively installed. Above the precision lifting micro-adjustment, a glassware base is installed. A leveling level is connected to the glassware base. A glassware is provided on the glassware base, and the glassware contains a liquid.

[0006] A limit ring, a sensor bracket, and a limit nut are provided on the column. The limit nut is installed at the top of the column. The limit ring is installed on the column. The sensor bracket is located between the limit ring and the limit nut, and a locking handwheel is installed on the sensor bracket.

[0007] A force-sensitive sensor is installed at the front end on the left side of the sensor bracket. A force-sensitive connection wire is connected to the force-sensitive sensor. A protective cover is provided outside the force-sensitive sensor. A force-sensitive sensor hook is installed at the bottom of the protective cover. A sample connection filament is connected to the bottom of the force-sensitive sensor hook, and a sample is connected to the sample connection filament.

[0008] The force-sensitive connection wire is electrically connected to the electric box.

[0009] Further, the precision lifting micro-adjustment includes a guide sleeve, a guide nut, a sliding column, a positioning ring, a guide pin, and a setscrew.

[0010] The guide sleeve is sleeved on the sliding column, the guiding nut is sleeved on the guide sleeve, the tip of the guide pin is installed on the side wall of the sliding column, and the head of the guide pin is located within the thread of the guiding nut;

[0011] The guide sleeve is connected to the base, and the sliding column and the base of the glassware are fixedly connected through the setscrew.

[0012] Further, a power supply, a voltage display, and a zero adjustment button are provided on the electric box.

[0013] Compared with the prior art, the present utility model has the following advantages:

[0014] For the liquid surface tension measuring experimental instrument of the present utility model, the precise lifting and fine adjustment ensure the height accuracy and repeatability during measurement, improving the reliability of the measurement results; the leveling feet and the leveling level simplify the equipment setup process, enabling users to quickly and accurately adjust the equipment to a horizontal state; the limiting rings and limiting nuts provided on the column offer an adjustable measurement range, allowing the equipment to adapt to glassware and samples of different sizes; the protective cover and hook provided outside the force-sensitive sensor protect the sensor from external factors and ensure the safe suspension of the sample; the power supply, voltage display, and zero adjustment button provided on the electric box offer an intuitive operation interface for users, facilitating measurement and data reading; in summary, the design of this liquid surface tension measuring experimental instrument focuses on precision, stability, safety, and user operation convenience, and is very suitable for higher education applications. Description of the Drawings

[0015] The drawings forming a part of the present utility model are used to provide a further understanding of the present utility model. The schematic embodiments and descriptions thereof of the present utility model are used to explain the present utility model and do not constitute an improper limitation to the present utility model. In the drawings:

[0016] Figure 1 is the overall schematic diagram of the liquid surface tension measuring experimental instrument according to the embodiment of the present utility model;

[0017] Figure 2 is the schematic diagram of the precise lifting and fine adjustment of the liquid surface tension measuring experimental instrument according to the embodiment of the present utility model;

[0018] Figure 3 is the schematic diagram of the electric box of the liquid surface tension measuring experimental instrument according to the embodiment of the present utility model;

[0019] Description of the reference numerals:

[0020] 1. Leveling foot; 2. Base; 3. Precision lifting and fine adjustment; 4. Base for glassware; 5. Leveling bubble; 6. Liquid; 7. Glassware; 8. Sample; 9. Sample connecting filament; 10. Hook of force-sensitive sensor; 11. Force-sensitive sensor; 12. Protective cover; 13. Sensor bracket; 14. Column; 15. Limit ring; 16. Limit nut; 17. Locking handwheel; 18. Force-sensitive connection wire; 19. Weight pan; 20. Weight; 21. Guide sleeve; 22. Guide nut; 23. Slide column; 24. Positioning ring; 25. Guide pin; 26. Set screw. Detailed implementation mode

[0021] It should be noted that, without conflict, the embodiments in the present utility model and the features in the embodiments can be combined with each other.

[0022] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "back", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0023] The present utility model will be described in detail below with reference to the drawings and in combination with the embodiments.

[0024] This embodiment relates to an experimental instrument for measuring the surface tension of a liquid. With the characteristics of precise lifting design, high processing precision, and large lifting range, the experiment is more convenient to operate.

[0025] Based on the above design concept, an exemplary structure of the experimental instrument for measuring the surface tension of a liquid in this embodiment is as Figures 1-3As shown in the figure, it mainly includes a base 2, a weight pan 19, weights 20 and an electric box. The bottom of the base 2 is equipped with leveling feet 1. On the left and right sides of the base 2, a precision lifting fine adjustment 3 and a column 14 are respectively installed. Above the precision lifting fine adjustment 3, a glassware base 4 is installed. A leveling level 5 is connected to the glassware base 4. A glassware 7 is provided on the glassware base 4, and a liquid 6 is contained inside the glassware 7; a limit ring 15, a sensor bracket 13 and a limit nut 16 are provided on the column 14. The limit nut 16 is installed at the top of the column 14, the limit ring 15 is installed on the column 14, and the sensor bracket 13 is located between the limit ring 15 and the limit nut 16. A locking handwheel 17 is installed on the sensor bracket 13; a force-sensitive sensor 11 is installed at the front end on the left side of the sensor bracket 13. A force-sensitive connection wire 18 is connected to the force-sensitive sensor 11. A protective cover 12 is provided outside the force-sensitive sensor 11. A force-sensitive sensor hook 10 is installed at the bottom of the protective cover 12. A sample connection filament 9 is connected to the bottom of the force-sensitive sensor hook 10, and a sample 8 is connected to the sample connection filament 9; the force-sensitive connection wire 18 is electrically connected to the electric box.

[0026] The precision lifting fine adjustment 3 includes a guide sleeve 21, a guide nut 22, a sliding column 23, a positioning ring 24, a guide pin 25 and a setscrew 26; the guide sleeve 21 is sleeved on the sliding column 23, the guide nut 22 is sleeved on the guide sleeve 21, the tip of the guide pin 25 is installed on the side wall of the sliding column 23, and the head of the guide pin 25 is located in the thread of the guide nut 22; the guide sleeve 21 is connected to the base 2, and the sliding column 23 and the glassware base 4 are fixedly connected by a setscrew 26; specifically, the guide sleeve 21 is connected to the base 2, the glassware base 4 and the sliding column 23 are connected and fixed by a setscrew 26. Rotating the guide nut 22 drives the guide pin 25 to move upward, which drives the sliding column 23 and the glassware base 4 to move upward. When rotating in the reverse direction, the glassware base 4 descends.

[0027] The electric box is provided with a power supply, a voltage display and a zero adjustment button. The power supply, voltage display and zero adjustment button on the electric box provide an intuitive operation interface for users, facilitating measurement and data reading.

[0028] When the liquid surface tension measuring experimental instrument described in this embodiment is in use:

[0029] 1. Place the instrument on the workbench, adjust the leveling feet 1, and level the instrument by observing the leveling level 5 under the glassware 7. Adjust the height of the column 14 and the effective height of the limit ring 15

[0030] 2. Calibration of the force-sensitive sensor 11 (required part):

[0031] The sensitivity of each force-sensitive sensor is different. Before the experiment, it should be calibrated first. The calibration steps are as follows:

[0032] Turn on the power switch of the electric box and preheat the instrument.

[0033] In the hook of the sensor beam end, hang the weight pan 19 and check if the voltage display of the voltmeter is zero. Adjust the zero-adjusting knob until the display shows zero.

[0034] Put weights 20 of 0.5 g, 1.0 g, 1.5 g, 2.0 g, and 2.5 g of equal mass into the weight pan respectively, and record the voltage value U under the action of the corresponding weight force F.

[0035] Use the least squares method to make a linear fit and calculate the sensor sensitivity K.

[0036] 3. Measurement and cleaning of the ring:

[0037] Measure the outer diameter D1 and inner diameter D2 of the sample 8 with a vernier caliper.

[0038] (1) The surface condition of the ring has a great influence on the measurement results. Before the experiment, the metal ring should be soaked in the NaOH solution for 20 - 30 seconds and then washed clean with pure water.

[0039] 4. Surface tension coefficient of the liquid:

[0040] (I) Hang the sample 8 on the hook 10 of the force-sensitive sensor, adjust the precision lifting fine adjustment 3, raise the liquid 6 in the glassware 7 to be close to the lower edge of the sample 8, and observe whether the lower edge of the sample 8 is parallel to the liquid surface to be measured. If not, after removing the sample, adjust the thin wire on the sample 8 to make the ring parallel to the liquid surface to be measured.

[0041] (II) Adjust the precision lifting fine adjustment 3 to gradually raise it, immerse the lower edge part of the sample 8 completely in the liquid 6 to be measured, and then reverse the precision lifting fine adjustment 3 to gradually lower the liquid surface. At this time, an annular liquid film is formed between the sample 8 and the liquid surface. Continue to lower the liquid surface and measure the voltage value U1 of the digital voltmeter at the moment before the annular liquid film is about to break and the voltage value U2 of the digital voltmeter at the moment after the liquid film breaks.

[0042] ∆U = U1 - U2

[0043] (III) Substitute the experimental data into the formula to calculate the surface tension coefficient of the liquid and compare it with the standard value.

[0044] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A liquid surface tension measuring test instrument, comprising a base (2), a weight plate (19), a weight (20) and an electrical box, wherein a leveling foot (1) is installed at the bottom of the base (2), characterized in that: A precision lifting and fine adjustment (3) and a column (14) are respectively installed on the left and right sides of the base (2); a glassware base (4) is installed above the precision lifting and fine adjustment (3); a leveling level (5) is connected to the glassware base (4); a glassware (7) is provided on the glassware base (4); and a liquid (6) is contained in the glassware (7); The column (14) is provided with a limiting ring (15), a sensor bracket (13) and a limiting nut (16); the limiting nut (16) is mounted on the top of the column (14); the limiting ring (15) is mounted on the column (14); the sensor bracket (13) is located between the limiting ring (15) and the limiting nut (16); and a locking hand wheel (17) is mounted on the sensor bracket (13); A force-sensitive sensor (11) is installed at the front end of the left side of the sensor bracket (13), the force-sensitive sensor (11) is connected to a force-sensitive connecting line (18), the outer cover of the force-sensitive sensor (11) is provided with a protective cover (12), the bottom of the protective cover (12) is installed with a force-sensitive sensor hook (10), the bottom of the force-sensitive sensor hook (10) is connected to a sample connecting filament (9), and the sample connecting filament (9) is connected to a sample (8); The force-sensitive connection line (18) is electrically connected to the electrical box.

2. The liquid surface tension measuring instrument according to claim 1, characterized in that: The precision lifting and fine-tuning (3) comprises a guide sleeve (21), a guide nut (22), a slide post (23), a positioning ring (24), a guide pin (25) and a top screw (26); The guide sleeve (21) is sleeved on the slide column (23), the guide nut (22) is sleeved on the guide sleeve (21), the tip of the guide pin (25) is installed on the side wall of the slide column (23), and the head of the guide pin (25) is located in the thread of the guide nut (22); The guide sleeve (21) is connected to the base (2), and the sliding column (23) is fixedly connected to the glass container base (4) via the top screw (26).

3. The liquid surface tension measuring instrument according to claim 1, characterized in that: The electric box is provided with a power supply, a voltage display and a zero adjustment button.

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