In the measurement of coating thickness, the Yunnai Series Thickness Gauges have become commonly used equipment in the industry due to their high precision and reliability. Among their components, the test gasket fixed under the electrolytic cell, though small in size, plays an indispensable role in the entire testing process. Its sealing performance and area-defining function directly affect the accuracy of test results; therefore, understanding its importance and replacement frequency is crucial.

01 The Importance of Sealing Performance

The primary function of the test gasket is to ensure sealing during the testing process. In the electrolytic thickness measurement method, the use of electrolyte is essential, and the gasket can effectively prevent electrolyte from leaking out of the test area. This sealing effect is particularly critical for samples with a width close to 2.5mm or a cylindrical diameter close to 4mm. Once the seal fails, electrolyte leakage will occur.

02 The Precision of Area Definition

The testing principle of an electrolytic thickness gauge involves electrolyzing the coating within a fixed area using a constant current to measure the coating thickness. The aperture of the test gasket directly determines the size of the test area. Once the test gasket is worn or cracked, the aperture will change, leading to deviations in test results—an enlarged aperture will result in larger test data.

The precision of area definition not only affects the results of a single test but also exerts a significant impact on the consistency of batch testing. On the production line, if the apertures of the test gaskets in multiple electrolytic thickness gauges are inconsistent, the test data of the same batch of products will show large differences, which in turn affects quality judgment. Therefore, when using thickness gauges, enterprises should replace the test gaskets regularly to ensure uniform testing standards across all equipment, thereby guaranteeing the stability of product quality.

03 The Necessity of Gasket Replacement

During use, the test gasket may be damaged due to wear, aging, or external forces. Common forms of damage include wear on the inner hole at the lower end, burrs, or cracks. Such damage not only impairs the sealing performance but also changes the aperture size, leading to distorted test results. Therefore, once any of the above damage signs are found on the gasket, it must be replaced immediately.

In addition to physical damage, the service life of the gasket is also an important factor to consider. Even if the gasket appears intact, after long-term use, it will lose elasticity due to material aging, thereby affecting its sealing and area-defining functions. It is recommended that the service life of the gasket should not exceed 3 months; for frequently used equipment, the replacement cycle should be shortened accordingly. If the enterprise has purchased additional calibration sheets, it can verify whether the gasket still meets the testing requirements through calibration. However, in any case, regular replacement is a necessary measure to ensure testing precision.

04 The Importance of Calibration and Maintenance

To ensure the testing precision of the electrolytic thickness gauge, regular calibration is an indispensable step. Calibration not only verifies whether the aperture of the gasket is accurate but also checks whether other performance parameters of the instrument meet the standards. It is recommended that enterprises send the thickness gauges to third-party testing institutions or back to the factory for professional calibration to ensure the authority and reliability of the test results. During calibration, technicians will conduct a comprehensive inspection of the equipment using standard samples and adjust or replace components in a timely manner if problems are found.

In addition to regular calibration, daily maintenance is also an important means to extend the service life of the test gasket. Operators should avoid scraping the inner hole at the lower end of the gasket with hard objects to prevent surface damage. Meanwhile, after testing, the gasket should be cleaned promptly to remove residual electrolyte and prevent corrosion of the rubber material. Furthermore, when storing the gasket, direct sunlight or high-temperature environments should be avoided to slow down the material aging process. Through scientific maintenance and upkeep, the service life of the gasket can be effectively extended, and the replacement frequency can be reduced.

05 Summary and Recommendations

We put forward the following recommendations:

First, establish a gasket replacement schedule and flexibly adjust the replacement time according to the frequency of use;

Second, prepare spare gaskets to avoid delays in testing progress due to sudden damage;

Finally, strengthen the training of operators to enhance their awareness of the importance of gaskets and standardize the usage and maintenance procedures.