Of all of these influences, the temperature of the water affects conductivity, and thus the
measurement of total dissolved solids, the most. Increased temperatures cause ions to move more
quickly; the probe reads this increase in activity as a higher concentration of ions. Conductivity
measurements should be taken at 25 °C or a temperature compensation factor must be applied to
the measurement. The conductivity reading of pure water can rise as much as 4.55% for every
1 °C deviation from 25 °C, while the reading of NaCl solutions rises 2.12%.