Today the configuration of the drain water pipes in the Y-arm was changed.
Finally, the pumps for the in-room pipes are stopped.
The readout of the flow meter becomes stable.
I also checked the spectrum of the portable seismometer located in the Y-end 1F.
Increasing around 1Hz and 20Hz after 13:45 is clearly seen.
There is no change around 11:11 work and it is consistent with the result of last week's study; the vibration of the in-room pipes is not propagated to the floor so much.
