Conductivity
Conductivity meters are used to quantify the amount of anions and cations present in a water sample and/or estimate the quantity of total dissolved solids present in a sample. There is one conductivity meter in the engineering laboratories. The conductivity meter uses a "drive" electrode to apply an alternating current at a constant rate to the sample. The "sense" electrode measures the strength of the electric field produced by the alternating current moving through the charged ions in the solution. By comparing a sample’s conductivity to a sodium chloride solution standard, sample conductivity concentrations are determined by the DO meter. Total dissolved solids may be estimated by multiplying the conductivity by a conversion factor dependendent of the type of water, i.e. freshwater, saltwater.