Conductivity is measured using a conductivity cell. Water is pumped through the conductivity cell, located in the WQM's Conductivity, Temperature, Dissolved Oxygen (CT-DO) chamber. A small electrical current is passed through the water between two electrodes connected to a computer processor. The electrical resistance of the water is measured and used to calculate conductivity which is then used to calculate salinity. Conductivity is measured in Siemens per meter (S/m).