EC and TDS

EC and TDS

Electrolytic conductivity (EC) is a measurement made in which electrical charges on particles in a medium are moved under the influence of a potential difference. EC is a measure of concentration, not for a specific ion type. An ion is a charged particle present in the solution that contributes to the current flow. Ions are formed when a salt such as sodium chloride is dissolved in water to form electrically charged particles. A simplified example is sodium chloride that separates into Na⁺ and Cl^–. However, the measurement is affected by many things such as the type of ionic compound(s) dissolved in the water, the ions mobility, the solution viscosity, temperature and concentration.

Electrical Conductivity uses units of Siemens/cm (S/cm, mS/cm, μS/cm, dS/m). For example, ultrapure water is said to have a conductivity of 0.055μS/cm at 25°C.