I have measured the new VB-S sample and again the original VB-plate in order to compare these two.
Surprisingly, the VB-S sample is more "black" than the original sample although the other way around should have been occured. Also, it seems that the VB-plate-blackness altered when comparing this with a measurement from January...

In all these, I have to add that the data in the measurement from January may be not comparable as the system was still under reconstruction at that time. Also, as it is the first time for me to use Torii-sans setup, I am not sure whether there is still a mistake in the absolute values...