According to this data, we suggest voltage are 4 grading.Three is about 15 mV and one is for NG.class interval:5 mVFormation 2 use three cycle show the best voltage drop, but three cycle we need to increase equipment and space, so we suggest use two cycle for formation2, and then increase the day of measure1.According to above data, we suggest the day of measure1 is second day.Measure 2 we need more data to confirm(12 day or 14 day).