Liquid LiPb blanket system is investigated in the fusion reactor. This study's purpose is the purity control of the oxygen and Hydrogen in LiPb using solid electrolyte sell. This system has the advantages such as capability of continuous monitoring without sampling.

In this experiment, the cell made of YSZ solid electrolyte was used for measuring partial oxygen potential in the range from 400 ~ 450 degree C.

Measured emf of the cell in LiPb is converted to oxygen activity with Nernst equation. And calculated oxygen activity in LiPb from thermodynamics theory agrees with observed value. The result of experiment shows the feasibility of the solid electrolyte cell.