Bay Instruments/WALZ

Easton,  MD 
United States
  • Booth: Supporter

Manufacturer of high precision Membrane Inlet Mass Spectrometers for environmental science. Featured product is PETREL, a small, low cost, and versatile quadrupole mass spectrometer for metabolic gas analyses in water or air. Bay Instruments is the exclusive representative in the US and Canada for WALZ PAM fluorometers and gas exchange equipment.


  • Membrane Inlet Mass Spectrometer
    Optimized for HIGH PRECISION measurement of DISSOLVED GASES. Unique design and software provides rapid, precise, and small volume capabilities required for denitrification and other challenging studies of aquatic metabolism....

  • Bay Instruments MIMS is a standard for high precision dissolved gas measurements of metabolic gases.  We provide >25 years of instrumentation development and optimization of MIMS for challenging measurements in the fields of denitrification, aquatic metabolism, and productivity.  Bay Instruments origins were in the development of the first MIMS instrument for N2/Ar measurements of denitrification.

    Capabilities of the MIMS

    Optimized for direct measurement of dissolved N2, O2, and Ar concentrations in environmental water samples 

    Precision of gas ratio (N2/Ar and O2/Ar) measurements (triplicate samples): 0.03%

    Precision of dissolved N2, O2, and Ar measurements (triplicate samples): 0.1%

    Does not require headspace equilibration

    Small sample sizes (3+ ml)

    Analysis time of 90 seconds per raw water sample, typical

    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

    Additional applications of our Mass Spectrometer

    Photosynthesis/respiration measurement on microalgae using liquid chambers with membrane inlets

    Heated gas injection inlet for gas analyses of headspace or other gas samples

    Continuous gas monitoring

    Features of our PETREL quadrupole mass spectrometer

    Automated valve control for pre-evacuating inlets

    Automatic protection of filament and SEM from inlet failure

    Precision of ion currents: 0.1%

    Precision of gas ratios: 0.03%

    15N,18O abundance (air): 1 per mil

    QuikData software for data visualization and handling that greatly improves performance evaluation and recording.


    WALZ PAM fluorometers and gas exchange instruments for photosynthesis

    We are pleased to be the exclusive representative in the US and Canada for the WALZ company.  WALZ is well know as the original manufacturer of PAM fluorometers and maker of high quality long lasting instruments.  Bay Instruments provides sales and technical support including training sessions for inexperienced customers.

    Highlighted WALZ products

    MICRO-PAM (new) for continuous monitoring of up to 16 leaves using one controller in the field or greenhouse

    DIVING-PAM-II for underwater coral or seagrass photosynthesis measurements

    MINI-PAM-II for field and lab in a compact case with full functionality without a computer connection

    PHYTO-PAM-II for distinguishing phytoplankton chromophoric groups (green, brown, PE-containing, PC-containing algae)

    DUAL-PAM-100 Sophisticated lab instrument for both PSII and PSI activity

    GFS-3000 gas exchange instrument for CO2 and transpiration

    ULM-500 PAR meter with both cosine and spherical sensors