subject: Using Conductivity Measurements to Determine Concentration of Dissolved Substances [print this page] The position of the sensor in the measurement beaker can influence the results (due to the occurrence of boundary effects outside the electrode surfaces). This of course depends on the design of the electrode. It is usually best to position the sensor in the middle. Low conductivities such as occur in pure water should be measured in a flow cell. The reason for this is atmospheric CO2. This dissolves in water forming carbonic acid and leads to errors in the conductivity results. The latter recommendation applies both to calibration and to measurements. The use of a flow cell prevents the sample coming into contact with air. The flow cell and tubing must be thoroughly rinsed before use.
Using Conductivity Measurements to Determine Concentration of Dissolved Substances
