Electrolytic conductivity: A reference system for aqueous solutions

To establish a system for the measurement of electrolytic conductivity in a queous solutions with traceability to the SI, a cell has been developed wit h a removable central section providing an accurate determination of the ge ometrical constant. As the concentration unit mass/mass, based and referred to the amount of substance in the SI, is recommended by international orga nisations, 0.1 molal KCl samples have been prepared and analysed. Results o ver a temperature range from 20 degreesC to 35 degreesC are presented. The main sources of error have been estimated and relative uncertainty has been assessed to remain at the level of 0.6 %. Satisfactory agreement is observ ed when the results are compared with the reference values available from l iterature.