Reasons for contamination of vacuum gauges

There are mainly the following points:

1、 Process factors

1. Residual gases in vacuum systems: If the vacuum system is not thoroughly cleaned and evacuated before use, the residual gases may contain various impurities such as oil vapor, water vapor, dust, etc. These impurities will deposit on the vacuum gauge under certain conditions, causing contamination.

2. Reverse diffusion of process gas: In some vacuum processes, the process gas used may reverse diffuse to the area where the vacuum gauge is located under the action of pressure difference. If the process gas contains components that are prone to condensation or adsorption, it will contaminate the vacuum gauge. For example, in processes using fluorine-containing gases, fluoride may deposit on the surface of the vacuum gauge.

2、 Equipment maintenance factors

1. Poor sealing: If the connection between the vacuum gauge and the vacuum system is poorly sealed, external air and impurities may enter the system, contaminating the vacuum gauge. For example, aging, damage, or improper installation of sealing gaskets can all lead to seal failure.

2. Improper maintenance: Improper operation during maintenance and overhaul of the vacuum system may also introduce pollutants. For example, when replacing or repairing a vacuum gauge, appropriate protective measures were not taken, resulting in impurities such as dust and grease entering the system.

3、 Environmental factors

1. Dust and impurities in the air: Even if the vacuum system is in a sealed state, it may still be connected to the external environment through small leakage channels. Dust, water vapor, and other impurities in the air may gradually penetrate into the system, contaminating the vacuum gauge.

2. Temperature and humidity changes: Changes in temperature and humidity may cause materials in the vacuum system to release gases or adsorb moisture, thereby increasing the impurity content in the system and contaminating the vacuum gauge. For example, in environments with significant temperature changes, certain materials may undergo thermal expansion and contraction, which can damage the seal and introduce external impurities.