Aso, Komori (remote), Takano, Washimi

Here is a brief report of the tapping test performed yesterday.

Sensitive points: the duct (Figure1) and the bottom where the pump has been located (Figure2)
Less sensitivie points: the top chamber (Figure3, Figure4), the floor smashing with a fist (Figure5)
Not sensitive points: the side hatches (Figure6), the floor close to a leg beneath OMMT1 (Figure7), the floor outside engiri (Figure8)

A short timeseries when tapping the duct is shown in Figure9. We can see an oscillation at 92.7 Hz in the feedback signsl (K1:OMC-PZT_HV1_OUT_DQ) and the error signal (K1:OMC-LSC_ERR_OUT_DQ), and the second harmonics of this can be seen in OMC TRANS.