Oxygen concentration

RBR standard instruments support several third-party DO sensors from Rinko, OxyGuard, and Aanderaa¹, which measure dissolved oxygen saturation.

When a sensor measures oxygen saturation, we derive oxygen concentration using the Weiss equation. See The solubility of nitrogen, oxygen and argon in water and seawater by R.F. Weiss for details.

The units of measurement may be µMol/L, mg/L, or mL/L for the OxyGuard DO and Rinko DO sensors; and mg/L or mL/L for the Aanderaa Optode DO sensors.

The Weiss equation requires values for absolute temperature (in °K) and salinity, which are derived from measured temperature and conductivity. If your instrument does not measure these, default values of 0°C (273.15°K) and 35PSU will be used. Alternatively, enter temperature and conductivity manually in the table under the Parameter tab in Ruskin. See Ruskin User Guide: Standard Instruments³.

¹ Aanderaa sensors report either oxygen saturation or oxygen concentration, depending on the RBR instrument.