Liquid contains sodium, potassium, chlorine, inorganic phosphorus and calcium, etc., and the integrated electrical conductivity of the electrolyte is called the conductivity rate (EC). Siemens (S) is a unit of the electrical conductivity. The conductivity of water is measured within a certain distance thus the input is in S/cm or mS/cm. Other electrical conductivity units are Mho cm, CF (in America and Australia) en EC.