How are conductivity and TDS related?
Salts, minerals, and even dissolved gases contribute uniformly to the conductivity of a solution. This means that the conductivity can be used as an indicator of the amount of dissolved materials in a solution. TDS can be used fairly accurately when comparing the status of a single source, such as NaCl, but error can arise when trying to compare two different types of solutions. It is necessary to calibrate the meter using the same dissolved materials that are in the test solution.
