It is important to measure dissolved oxygen in the wastewater effluent before discharge. The concentration of DO in water is affected by ambient temperature, atmospheric pressure, and salinity of sample. The Rugged Dissolved Oxygen (RDO) probe features automatic temperature compensation for the most accurate oxygen measurements. The RDO meter compensates readings for the sample salinity. If the salinity of the sample is 1 ppt (~0.5 mS/cm conductivity) or more, use the salinity correction.  See Electrode Log 54 Correcting DO Measurement for Salinity for details.