WQM: Conductivity to Salinity Conversion
- Salinity is a measure of the mass of dissolved salts (ionic constituents) in a given mass of solution and usually expressed as parts per thousand (ppt).
- Ions commonly found in water include calcium, magnesium, potassium and sodium cations and bicarbonate, carbonate, chloride, nitrate, and sulfate anions.
- Conductivity is a good measure of salinity in water. Other indirect measures are water density, sound speed, and refractive index. All can be used to calculate salinity.
- Collect conductivity (uS/cm) and water temperature (C) data.
- Use spreadsheet or calculator to convert conductivity and temperature data to salinity value.
- Equations used are based on the practical salinity scale and are valid for surface waters with salinity between 2 and 42 ppt. Please view the source to this document and consult Standard Methods for the Examination of Water and Wastewater if you have questions or concerns.