Uncertainty Estimation for the Measurement of Electrolytic Conductivity by Secondary Method Using Cell Type D

Abstract

Electrolytic conductivity measurement is one of the important parameters to evaluate the concentration of dissolved substances in a solution and has been widely used in various fields of life, science, and technology. It was being used for process control and quality assurance. The traceability of the measuring results is a crucial requirement to guarantee reliability. The electrochemistry laboratory - chemical metrology Indonesia has started to develop a secondary method for electrolytic conductivity measurement. The objective of this work is to provide a traceability chain for electrolytic conductivity measurement in Indonesia through secondary reference material of Potassium Chloride (KCl) 1 M. The secondary reference material of KCl 1 M can be used as a standard for calibrating the conductivity meter, especially in seawater analysis. The secondary reference material that is developed has an electrolytic conductivity value of about 111 mS/cm and was measured using cell type D from ZMK, Germany. This cell is made from glass with two platinization electrodes inside. The distance of the electrodes is 60 mm, and the diameter of the electrode is 20 mm. The uncertainty measurement was estimated according to the ISO GUM recommendation by identifying all possible uncertainty sources in the electrolytic conductivity measurement process. The result showed that the expanded uncertainty of electrolytic conductivity measurement for KCl 1 M by a secondary method using cell type D was 0.33% at k=2 for 95% confidence level with a repeatability of the measurements and cell constant as the biggest sources of uncertainty which contributed as 80% and 17%, respectively.

Validation of a Secondary Method Using Jones Cell - Type D for Electrolytic Conductivity Measurements

“…The uncertainty estimation of KCell determination and the  value measurement by the secondary method using the Jones cell has been discussed in the previous literature (Hindayani et al, 2019). However, there 3 and 4.…”