Calculations of thermal junction potential and calibration of an External Pressure-balanced Reference Electrode

摘要

The electrochemical corrosion measurements in subcritical and supercritical aqueous solutionsrequire utilization of reliable reference electrodes. The most widely accepted reference electrode isthe external pressure-balanced reference electrode (EPBRE). This study presents the constructionand characterization of an external pressure-balanced reference electrode to be used in an autoclave.The equilibrium potential measurements were performed using this reference electrode in the Cu/Cu2+ system. The deviation of the measured potential was attributed to i) thermal junction potential, ii)liquid junction potential, and iii) Ohmic voltage drop. The available data were used to estimate themagnitude of these values and compared with the measured values for the Cu/Cu 2+ system.