Instruction Manual CON 6/TDS 6
44
Conductivity and Temperature
Conductivity in aqueous solutions reflects the concentration, mobility, and
charge of the ions in solution. The conductivity of a solution will increase with
increasing temperature, as many phenomena influencing conductivity such as
solution viscosity are affected by temperature.
The relationship between conductivity and temperature is predictable and
usually expressed as relative % change per degree centigrade. This
temperature coefficient (% change per degree) depends on the composition of
the solution being measured. However, for most medium range salt
concentration in water, 2% per degree works well. Extremely pure water
exhibits a temperature coefficient of 5.2%, and concentrated salt solutions
about 1.5%.
Since temperature affects the conductivity measurement so profoundly, the
usual practice is to reference the conductivity to some standard temperature.
This is typical 25 °C, but the CON 6 and TDS 6 meters permit the choice of 20
°C or 25 °C in the advance setup menu.
Both meters permit you to enter the temperature coefficient which best suits
your sample and use an ATC probe to automatically temperature compensate
back to the chosen reference temperature.
