Columbus Instruments Micro-Oxymax Respirometer


A highly adaptable general purpose closed circuit respirometer with very high sensitivity.


The Columbus Instruments’ Micro-Oxymax system is a highly adaptable general purpose closed circuit respirometer. The system monitors the concentration of gas contained within an enclosed head space into which the material being monitored is respiring. Periodic sensing of the gas concentration, along with an equally accurate measurement of the volume of the head space, allows calculations of incremental and accumulated values for consumption and production. The Micro-Oxymax patented design principle provides a sensing threshold near 2 x 10-7 litre per hour.




Product Details

The system can be configured for single or multiple gas sensing. Oxygen, Carbon Dioxide, Methane, Carbon Monoxide, Hydrogen Sulfide and Hydrogen can be sensed over specially selected ranges to meet almost any application. The Micro-Oxymax can be configured to monitor from one to 80 chambers.


Combining multiple gases, high sensitivity and multiple chambers with computer controlled operation makes The Micro-Oxymax unsurpassed in flexibility. The instrument finds application in all of the life sciences. It may be used for microbial respiration most often associated with environmental soil and water research; food science and preservation, insect respiration, tissue and skin respiration, plant research, and a wide range of other applications.


The modular design of the Micro-Oxymax allows an initial configuration for basic investigations that can be expanded later to include additional gases and/or chambers. The Micro-Oxymax software handles the details of data collation and the complexities of accommodating additional samples within the current experiment.


The Micro-Oxymax also allows operation under testing conditions that limit all other manometric and electrolytic based respirometers. The system automatically compensates for changes in pressure and temperature. In addition, the Micro-Oxymax will initiate refreshing of the head space gas if concentrations deviate beyond operator prescribed limits. The Micro-Oxymax keeps an accurate account of system performance and prevents problems before they happen. Internal diagnostics thoroughly test the configuration you’ve selected and make recommendations to optimize conditions for a successful test.


  • High Sensitivity: 2×10-7 litre of gas per hour
  • Supported gases:
    • O2: 0-1%, 19-21%, 0-100%
    • CO2: 0-1%, 0-3%, 0-10%, 0-100%
    • CH4: 0-1%, 0-5%, 0-10%, 0-30%, 0-100%
    • CO: 0-1%, 0-10%
    • H2: 0-2000ppm
    • H2S: 200ppm
    • NO2: 150ppm
    • N2O: Contact us for available ranges
  • Multiple Chamber Sensing: 1 to 80 Chambers
  • Fully automated operation
  • Maximum Head Space Volume: 50mL to 10L m), H2 (0-2000 and 0-10,000ppm)


  • Anaerobic
  • Aqueous
  • Compost
  • Marine
  • Sewage and Wastewater
  • Soil