Conductivity Conductivity is a measure of the ability of water to pass an electrical current. As the concentration of salts in the water increases, electrical conductivity rises-the greater the salinity, the higher the conductivity. Organic compounds like oil, phenol, alcohol, and sugar do not conduct electrical current very well and, therefore, have a low conductivity when in water. Conductivity is measured with a probe and a meter. Conductivity meters require temperature correction and accurate calibration can be difficult.
Voltage is applied between two electrodes in a probe immersed in the sample water.
The drop in voltage caused by the resistance of the water is used to calculate the conductivity per centimeter. The meter converts the probe measurement to micromhos per centimeter and displays the result for the user. Some conductivity meters can also be used to test for total dissolved solids and salinity. Meters should also measure temperature and automatically compensate for temperature in the conductivity reading. Conductivity can be measured in the field or the lab.