[YokozaWashimi]
We started the PEM measurements in power-outage environment with battery operation, near the OMC chamber.
The reference data during night were not taken because someone kindly turned off our setup without asking us!!!
The data during 13:18~13:48 JST has signal, but that of 15:18~15:48 JST has no signal.
Then, this is also a measurement how "kind" your colleagues are. (and the information would be useful to estimate to what extent we need to prepare of fool-proofing.)
I am not the kind "someone", but let me put something. When I saw the setup in the evening yesterday, I felt confused why this was left turned on; maybe the memo on the box would not contain sufficient information. Anyway, I myself could estimate what PEM would like to do by taking combination of (a) the information left in my brain and (b) the memo on the box, but I do not think everyone could succeed to combine the information.
Thank you for your comment.
the memo on the box says "PEM measurement 2020/10/13~14", and we announced this work in KOUTEI-KAIGI and Chief meeting...
Quick report of the result.
Figure 1 : ASD and coherence for each sensors during today's power outage (13:40~14:10)
Figure 2 : Comparison between today (blue) and yesterday (gray)
(sorry, "VOLT" plot is misreading. the full scale was changed)
So quiet!!!
Measurement is still going.
We will remove them tomorrow.
Thanks for the interesting plots!
By the way, "VOLT" is measuring what? The Power supply line?
It means the voltage difference between OMC chamber and OMC rack ground
Oct.14 13:40~14:10 vs Oct.15 02:26~0.:56
The difference of "Volt" was real!
Same noise enhancement was measured around 100Hz in the vibration noise in the cryostat by Ochi-kun in the past. This origin was identified.