The sealing performance test of quartz instruments is a key step to ensure that they can effectively prevent gas or liquid leakage in various application scenarios. Quartz materials are widely used in the semiconductor, optical, chemical, medical and other fields due to their excellent chemical stability, high-temperature resistance and transparency. Quartz instrument, however, the sealing performance of direct impact to its use effect and security, so need to pass the test of scientific and systematic methods to evaluate the sealing performance.

1. The importance of sealing performance testing

The sealing performance of quartz instruments directly affects their reliability and safety in practical applications. For example, poor sealing of the quartz reaction chamber in the semiconductor manufacturing process can result in the leakage of process gases, which can affect product quality and even cause safety accidents. In optical domain, poor sealing can result in contamination of the internal environment, which affects optical performance. Therefore, testing the sealing performance is an important part of quality control for quartz instruments.

2. The main methods for sealing performance testing

(1) Air pressure test method

The air pressure test method is one of the most common ways of evaluating the sealing performance of quartz instruments. The basic principle involves filling the instrument with gas at a certain pressure and observing the resulting pressure changes to determine whether there is any leakage. The specific steps are as follows:

- Connect the quartz instrument to the air pressure testing equipment and ensure that the connection is well sealed.

- Fill the instrument with gas (usually air or inert gas) to reach the preset pressure value.

- Maintain the pressure for a period of time and observe whether it drops.

- If the pressure drop exceeds the allowable range, it indicates that there is a leakage in the instrument.

The air pressure test method has the advantages of simple operation and high sensitivity, making it suitable for detecting the sealing performance of most quartz instruments. However, it has two drawbacks: its ability to detect minor leaks is limited, and professional testing equipment is required.

(2) Vacuum test method 

The vacuum testing method is applicable to quartz instruments that require operation in a high vacuum environment. The principle involves evacuating the interior of the instrument and observing the change in vacuum degree to determine whether there is a leakage. The specific steps are as follows:

Connect the quartz instrument to the vacuum pump and ensure that the connection is well sealed.

- Start the vacuum pump and evacuate the interior of the instrument until it reaches the preset vacuum level.

- Turn off the vacuum pump and observe whether the vacuum degree rises.

- If the vacuum degree exceeds the permissible range, it indicates the presence of a leakage in the instrument.

The advantage of the vacuum testing method is that minute leaks can be detected and it is suitable for high vacuum application scenarios. However, it requires high-precision vacuum detection equipment and is relatively expensive to implement.

(3) liquid immersion method

The liquid immersion method is an intuitive testing method for sealing performance, suitable for detecting whether there is obvious leakage in quartz instruments. The principle is to immerse the instrument in the liquid and check for the production of any bubbles. The specific steps are as follows:

- Immerse the quartz instrument completely in a liquid (usually water or alcohol)

- Fill the instrument with gas and observe whether there are bubbles on the surface of the liquid.

- If bubbles continue to form, it indicates that there is a leakage in the instrument.

The liquid immersion method is advantageous due to its simplicity and cost-effectiveness, making it well-suited for preliminary detection. However, its ability to detect minor leaks is limited, and it is not suitable for some quartz instruments that are sensitive to liquids.

3. Precautions for sealing performance testing

(1) Selection of the test environment

The sealing performance test should be conducted in a clean, dust-free environment to prevent external factors from interfering with the results. The temperature and humidity of the testing environment should also be kept within a reasonable range to ensure accurate results.

(3) Settings of test pressure

The test pressure should be set according to the actual usage conditions of the quartz instrument. Excessive pressure may cause damage to the instrument, while insufficient pressure makes it impossible to effectively detect leaks. Therefore, the setting of the test pressure should take into account the material characteristics of the instrument comprehensively

(3)  Control of test duration

The duration of the test directly affects the accuracy of the results. If the time is insufficient, slow leaks might not be identified; if it is excessive, it may elevate the testing expense. Therefore, the test time should be set at a reasonable length according to the size of the instrument and the sealing performance requirements.

(4) Recording and analysis of test results

The results of the sealing performance test should be recorded in detail, including parameters such as test pressure, test time and leakage volume. Analyzing the results enables us to determine whether the sealing performance of instrument meets the requirements and provides a basis for subsequent improvements.

5. Conclusion

The sealing performance assessment of quartz instruments constitutes a pivotal element in ensuring their reliability and safety in practical applications. Various methods, such as air pressure testing, vacuum testing and liquid immersion testing, can be used to comprehensively evaluate the sealing performance of quartz instruments. During the process of testing, meticulous attention should be paid to the analysis of the testing environment, testing pressure, and duration of testing to ensure the accuracy and reliability of the results. Scientific sealing performance tests can effectively improve the quality of quartz instruments to meet the demands of different application scenarios.