Conductivity

The conductivity value monitors the total ion concentration in the measured solution, which comprises secondary information about the total volume of salts, free acids and alkalines.
The basic unit for conductivity measurement is S/m. In practice the units used most are uS/cm and mS/cm. For water solutions conductivity starts at 0.05 uS/cm for ultra clean water and ends at values of 1S/cm for some alkalines.
Aside from ion concentration, conductivity is influenced by ion movement, which is dependent on temperature. In usual cases temperature dependence can be considered as being linear with a temperature dependence coefficient of about 2.2 %/°C. The result of the measurement should usually be information about the total volume of salt, for which it is necessary to eliminate temperature dependence. Therefore conductivity measurement instruments convert the actual measured value to conductivity, which should be measured at 25°C.
The measured conductivity can be influenced by sensor pollution, above all, by pollution with a non-conducting coating.