The Operation of the Residual Gas Analyzer
Vacuum systems are effective for many applications, and in some processes, gas is used as part of the vacuum method. As even trace amounts of gas can affect many processes, it is required to check the presence and levels of such gases. A residual gas analyzer can detect trace amounts of gas in the industry and in laboratories, and its high effectivity makes this machine mandatory in various vacuum-based techniques.
A residual gas analyzer or RGA is a type of mass spectrometer that monitors contamination and allows for process control in various vacuum systems. The monitoring is performed with two main types of residual gas analyzers that can be used for various processes:
Open ion source – the most widely used type of residual gas analyzer; this machine measures pressure based on the mass of each atom that passes through the quadrupole. The OIS will usually be mounted and attached to the vacuum chamber, and molecules move through its ion source.
The main advantage of the OIS residual gas analyzer is its ability to detect residual gas without affecting the gas composition inside the vacuum chamber.
Closed ion source – A type of residual gas analyzer that is mounted atop the quadrupole mass filter of a vacuum chamber. The CIS consists of a shirt gas-tight tube and has two openings to allow ions to exit and electrons to enter.
The role of both types of residual gas analyzers is to detect the presence of residual gases that stem from virtual leaks, real leaks, and chamber wall outgassing. Traditional gas leak detectors cannot differentiate between different types of gases and their species, while a residual gas analyzer has the ability to do so. This quality allows for the accurate detection and monitoring of residual gases in vacuum systems, making it possible to improve techniques and extract gases that affect production and other processes.