Specializing in High Precision Membrane Inlet Mass Spectrometers

Precise ● Rapid ● Small Volumes ● Versatile

Bay Instruments MIMS

"We believe in keeping it simple, which many of our clients appreciate."

Bay Instruments has 25+ years of experience designing and building membrane inlet mass spectrometers (MIMS) for the environmental community. Bay Instruments MIMS have facilitated breakthrough advances in denitrification research by providing state-of-the-art precision for the measurement of dissolved gases in water. Emerging applications include river and lake system metabolism, ocean trace gas analysis, metabolic gas studies and photosynthetic isotopic studies.

Bay Instruments MIMS




Capabilities of Our MIMS

  • Direct measurement of dissolved N2, O2, and Ar concentrations in environmental water samples
  • Small sample sizes (3+ ml)
  • Does not require headspace equilibration
  • Analysis time of 90 seconds per raw water sample, typical
  • Precision of dissolved N2, O2, and Ar measurements (triplicate samples): 0.1%
  • Precision of gas ratio (N2/Ar and O2/Ar) measurements (triplicate samples): 0.03%
  • Detects stable isotopes
  • Automatic recording of dissolved gas trends in ‘strip chart’ mode
  • Can be applied to CO2, CH4, DMS, and other low molecular weight dissolved gases

Bay Instruments offers a unique MIMS that is optimized for the challenging requirements of environmental science. We currently have instruments in 13 countries and numerous universities and research facilities throughout the United States. Our first installed instruments are still going strong, after 20 years. Our niche market for measurement of the dissolved air gases has been our emphasis and Bay Instruments remains close to the environmental science and oceanography communities.

The N2/Ar technique for denitrification is effectively synonymous with the Bay Instruments’ MIMS. However, we are always open to new applications that would benefit from our MIMS solution. We have worked with industry and government laboratories (see Applications) developing new capabilities and applications. We have a track record of working with end-users and subsidizing feasibility projects prior to purchase commitments. Sometimes it pans out, sometimes it doesn’t.

The Bay Instruments MIMS is the culmination of 25+ years of identifying, understanding and optimizing the technique for high precision, high accuracy, and high reliability. We make quadrupole mass spectrometers perform like high-performance isotope ratio mass spectrometers, from the data perspective, and at substantial savings. We have also assisted others in retrofitting their non-optimal MIMS instruments with our membrane inlet configuration.

We believe in keeping it simple, which many of our clients appreciate. Nuances of the instrument and applications are many and our clients value our accumulated knowledge and expertise.

Our membrane inlet mass spectrometers are optimized for the demands of environmental scientists who require very high precision dissolved gas measurements. They include built-in versatility for other membrane configurations or gas inlets. Bay Instruments integrates and augments quality Pfeiffer Vacuum quadrupole mass spectrometers (QMS) in its products. You can choose from PrismaPlus or HiQuad systems that we specify for your applications and requirements. We have extensive experience optimizing the membrane inlet and mass spectrometer operational conditions to provide the high precision demanded of our clients.





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