as the vacuum level was good enough, I asked Eric Mistretta to open the 2 valves of the FP cavity.

He said the vacuum group made several tests during the last days, opening and closing these valves!
I asked him to not open and close them as it could release some dust on the mirrors.

Eric opened the valves in "local mode", using directly the valves controller (see attached image).
He was unsure of what could happen if he switches to the "remote mode"... the valves could be commanded to close again.
so, for the moment, one stays in "local mode".

after opening the valves, the vacuum level started to decrease inside FP-cavity :
9.7e-10 mbar for the left vessel
1.7e-9 mbar for the right vessel