Surface tension is a key physical parameter that characterizes the properties of liquids and is crucial in product development and quality control in industries such as petrochemicals, pharmaceuticals, coatings, and daily chemicals.The surface tension tester is a precision device used to obtain this parameter. Irregular operations can directly introduce errors, leading to data distortion.Therefore, strict adherence to standardized usage methods is fundamental to ensuring the accuracy and reliability of measurement results.

　　1、 Preparation before measurement: laying the foundation for accuracy

1. Environment and sample preparation:

① Environmental control: Ensure that the laboratory environment is free from vibration, airflow interference, and stable temperature, as temperature has a significant impact on surface tension.

② Sample preparation: Pour the liquid to be tested into a clean and dry sample dish, with enough liquid to submerge the measuring element. For liquids that are prone to volatilization or adsorption of impurities, they should be prepared and tested on site, and covered to prevent volatilization.

③ Container cleaning: The sample dish must be absolutely clean, as any trace contamination can seriously alter the surface tension of the liquid. It is recommended to use chromic acid solution or specialized cleaning agent for cleaning, then rinse repeatedly with ultrapure water, and dry for later use.

2. Instrument calibration and component cleaning:

① Instrument zeroing: After preheating to stability, perform electronic zeroing in an unloaded state.

② Component cleaning: This is one of the most critical steps. Measuring elements (platinum plates or platinum rings) used for direct contact with liquids must be strictly cleaned:

Burning method: Burning on an alcohol lamp flame until red hot can remove organic pollutants. This method is applicable to platinum components.

Solvent cleaning: Soak and rinse with high-purity solvents such as acetone and ethanol to remove oil stains, then rinse with ultrapure water, air dry or blow dry with a hair dryer.

③ Handheld specifications: It is strictly prohibited to touch the cleaned components directly with hands. Clean tweezers must be used for operation to prevent sebum contamination.

　　2、 Measurement process: Fine operation to obtain real data

1. Installation and positioning:

① Use tweezers to firmly install the clean and dry measuring element onto the force sensor.

② Use the instrument lifting platform to steadily raise the sample dish to near the liquid level. For the hanging plate method, the bottom edge of the platinum plate should be parallel to the liquid surface; For the lifting ring method, it is necessary to adjust the ring to be parallel to the liquid level.

2. Perform measurement:

① Automatic measurement: Modern instruments often have an automatic measurement mode. Slowly raise the sample stage until the platinum plate contacts the liquid surface and is submerged to the specified depth (usually around 0.1mm), and the instrument will automatically detect and record the maximum surface tension value.

② Manual measurement (lifting ring method): Slowly lift the sample stage to bring the ring into contact with the liquid surface and pull up a liquid column. Carefully observe the shape of the liquid film and record the maximum value displayed by the force sensor at the moment when the liquid film is about to rupture. This process needs to be slow and uniform to avoid impact.

③ Real time observation: Pay close attention to the contact between the measuring element and the liquid surface to ensure a smooth process without bubble interference.

3. Data recording: Record the measurement results and also record the ambient temperature. Each sample should be measured at least 3 times and the average value should be taken to evaluate the repeatability of the data.

　　3、 Measurement post-processing: maintenance and data analysis

1. Component cleaning and storage: After the measurement is completed, immediately clean the measuring components according to the above method, dry them, and place them in a dedicated storage box to prevent collision and contamination.

2. Sample handling: Properly dispose of waste liquids and clean sample dishes.

3. Equipment shutdown: Turn off the instrument power and fill in the usage record.

4. Data analysis: Combined with temperature measurement, make necessary corrections to the data. If the deviation of multiple measurements is too large, it is necessary to investigate reasons such as pollution, temperature fluctuations, or operational errors.

Conclusion

The operation of a surface tension tester is an art that combines patience, meticulousness, and rigorous science. From the cleanliness of components, stable control of the environment, to precise judgment of measurement moments, every step directly affects the quality of data. Strictly adhering to this regulation is not only a care for expensive instruments, but also a reverence for the authenticity of scientific data. Only in this way can reliable data be captured from tiny liquid surfaces, providing solid support for scientific research and industrial innovation.