Residual Gas Mass Spectroscopy – In-Depth

Residual Gas Mass Spectroscopy Specifications:

  • Stanford Research Systems RGA200 Residual Gas Analyzer
  • Mass Range: 1 to 200 amu
  • Mass Filter Type: Quadrupole
  • Detector Type: Faraday Cup and Electron Multiplier
  • Resolution: Greater than 0.5 amu at 10% peak height
  • Minimum Detectable Partial Pressure: 5 x 10-11 Torr with Faraday Cup
  • Minimum Detectable Partial Pressure: 5 x 10-14 Torr with Electron Multiplier
  • Operating Pressure Range: 10-4 Torr to UHV with Faraday Cup
  • Operating Pressure Range: 10-6 Torr to UHV with Electron Multiplier
  • Ionizer: Open, cylindrical symmetry ion source
  • Filament: Thoriated Iridium

Residual Gas Mass Spectroscopy Applications:

  • Detection of outgassed airborne silicone materials
  • Outgassing of water from materials
  • Identification of chemicals outgassed by materials
  • Chemical purity checks
  • Identification of volatile contaminants
  • Leak detection for vacuum systems

How does Residual Gas Mass Spectroscopy Work?:

The RGA efficiently identifies the chemical constituents of gases within a vacuum by ionizing the present gases, creating ions, and subsequently determining their mass-to-charge ratio.

A standard RGA is comprised of key components: the sensor, the interface box, and the controller.

Within the sensor, the RGA generates a stream of ions through gas collisions with electrons emitted from a hot cathode. These ions are then filtered based on their mass-to-charge ratio, denoted as m/z. The resulting output current serves as a measurement of the abundance of ions with a specific m/z that successfully pass through the filter. Detection of this current occurs at the detector, facilitated by either a Faraday cup or a Secondary Electron Multiplier.

The signals, processed initially by the interface electronics and subsequently by the control unit, generate a graphical representation on the x-axis depicting the m/z ratio, while the y-axis represents the corresponding ion current.

Stanford Research Systems RGA200 Residual Gas Analyzer (for Residual Gas Mass Spectroscopy)
Stanford Research Systems RGA200 Residual Gas Analyzer

Reach out to us today to discuss your materials analysis concerns and we will discuss how our 25+ experience can help you and your company with your materials concerns.