[Hirayama, Sekiguchi, Miyo]

We calculate Bottom Filter LVDT calibration factor.
The factor is -2923.4+/-5.2 count/mm around 69 mm. (Please see attached picture)
Data and script for the calculation is on the KAGRA dropbox.

Compared with F2 at the EY suspension(klog:2665), count vs displacement is different.
It caused by the difference polarity of the coil. maybe.