842-023 is a high-performance replacement tungsten filament assembly designed for Open Ion Source (OIS) mass spectrometry analyzers. This field-serviceable component provides the thermionic emission of electrons required to ionize gas molecules in Residual Gas Analyzers (RGAs) and process monitoring systems.

The user serviceable analyzer design allows the ion source to be easily removed and dismantled for cleaning. The dual independent filaments on the MKS analyzers can be easily changed by removing the two barrel connectors and loosening the two holding screws.

Tungsten filaments are the primary choice for vacuum environments where there is a risk of chemical contamination that would degrade coated filaments. However, they are sensitive to oxygen and can rapidly oxidize if exposed to high pressures while hot.

Tungsten filaments are suited for applications where backstreaming of oil from diffusion pumps is heavy. The hot tungsten filaments react with oxygen to rapidly form tungsten oxide and therefore poor vacuum can rapidly cause catastrophic oxidation of hot tungsten components.

To verify compatibility with specific RGA models, consult the “specifications” section below.