Conductivity increases with increasing amount and mobility of ions.
These ions, which come from the breakdown of compounds, conduct electricity because they are negatively or positively charged when dissolved in water. Therefore, SC is an indirect measure of the presence of dissolved solids such as chloride, nitrate, sulfate, phosphate, sodium, magnesium, calcium, and iron, and can be used as an indicator of water pollution. Measurement of SC Specific Conductance measures how well water can conduct an electrical current for a unit length and unit cross-section at a certain temperature. Resistance means how well something can resist an electrical current, and is reported in ohms. One siemen is equal to one mho.