The «miniRUEDI» is a portable mass spectrometer for quantification of He, Ne, Ar, Kr, N2, O2, CO2, CH4, H2 and other gas species in gases and water.

The miniRUEDI is designed for environmental research and allows maintenance-free on-site gas analysis during field work at remote locations. The miniRUEDI was (and is) developed at the Swiss Federal Institute for Aquatic Science and Technology (Eawag).

The unique coupling of a membrane inlet to the mass spectrometer allows simple but accurate quantification of dissolved gas concentrations in water.

All instruments are custom-built and may be adapted to suit specific customer requirements.


  • Accurate quantification of He, Ne, Ar, Kr, N2, O2, CO2, CH4, H2, etc. in gases or in water.
  • Unique membrane gas inlet for accurate, unbiased quantification of dissolved gases in water (patent application pending).
  • Simple and reliable calibration using ambient air or custom gas standards — also for water analysis! No need for calibration of water analyses using external water standards with known gas concentrations, which are challenging to manufacture and handle.
  • Designed and built for maintenance-free on-site gas analysis at remote locations: simple and automated calibration, low power consumption, rugged construction, maintenance free, options for remote control.
  • Gas inlet at atmospheric pressure with six inlet ports for different gas samples (number of inlets can be increased on request).
  • Size and weight (incl. carrying case): 80 cm × 52 cm × 32 cm / 32 kg (can be transported as normal passenger luggage with most airlines).
  • Power supply: 24 V(DC), runs off 110–230 V(AC) mains converter (included), batteries, solar panels, etc. Power consumption: 50 W (normal operation).
  • Open-source software toolbox for instrument control and data processing allows flexible implementation of custom analysis procedures and data processing (Python, GNU Octave).

Further information:


  • GE-MIMS membrane modules for dissolved gas analysis in water
  • Total gas pressure sensors (e.g., for GE-MIMS analysis), compatible with ruediPy software
  • Temperature sensors (e.g., for GE-MIMS analysis), compatible with ruediPy software