First plot shows the general trend (acceleration on the bench and on the west flange of the WE tower).
Conclusions:
1) The turbo pump is not the limiting the seismic noise around 100Hz. Switching it off had no effect then.
2) The air conditioning machines are the limiting noise around 100Hz. Switching them off improved the sensitivity around 100Hz.
3) The sensitivity is not stationary around 50 and 100Hz. The noise modulation is slowing down and down after the lock acquisition. This is modulating the all horizion (see 2nd plot). The same modulation is seen for the 100Hz bump and 50Hz bump. But it is not clear if the 50Hz bump disappeared when the air conditioning was switched off as unfortunately the noise was minimum at that time.
3rd plot is comparing the sensitivity when AC is off compared with one of the best ones in the past days.
