EC/TDS-meters

EC- Indicates the electrical conductivity of a solution, measured in millisiemens (mS)TDS- Indicates the salt content of a solution, measured in parts per million (ppm) is a unit that expresses the numerical ratio of one part per million of a whole:This unit is used to express relative size in terms of parts per million (as percentages are used to express parts per hundred).1 ppm = 0.001‰ = 0.0001%.parts per billion, abbreviated as ppb (parts per billion), 1 ppb = 10-9 parts per trillion, abbreviated as ppt (parts per trillion), 1 ppt = 10-12 parts per trillion.