Calibrated measured potentials on the SESAME-PP receiving electrodes –Y and +Y for the four measurement blocks of the FSS. a) The temperatures used for calibration are those measured by the SESAME-CASSE PT1000 sensors. The potential of the +Y electrode decreases with time. b) The temperatures used for the calibration for the –Y electrode and the FSS4 measurements of the +Y electrode are those measured by the SESAME-CASSE PT1000 temperature sensors, minus 10 °C. The drop in potential of the +Y electrode has now disappeared.