1) Calibrated the LVDT in the F2. Tuned the demodulation phase and amplitude in the driver some times.
In any cases, the sensing range was very narrow.
2) Measured the transfer function of F2 without additional load. The proper frequency was 0.63Hz with 67.0mm in keystone height.
3) Made more compression for the 6 blades; 0.5mm for 4 blades and 1.5mm for 2 blades respectively.
4) Measured the transfer function again. The proper frequency was 0.38Hz with 65.5mm in keystone height.
