Reports until 09:25, Tuesday 12 November 2019
LHO VE (DetChar, PEM)
chandra.romel@LIGO.ORG - posted 09:25, Tuesday 12 November 2019 - last comment - 13:48, Tuesday 12 November 2019(53180)
pneumatic gate valves in corner & interesting observation

I increased the pressure at GV 6,8 gate piston from 55 psig (GV6) and 52 psig (GV8) to maximum (~ 85 psig) and then valved out instrument air from compressor and valved in instrument air from bottled N2 in mechanical room. Kyle has already maximized pressure at GV 5,7. GV5 is reading ~90 psig, but GV7 is sitting at 60 psig.

Worth noting that when I increased the pressure at GV6, I heard a noise of the gate moving, suggesting it wasn't fully lifted. A wiggly gate could have been a noise source. Request for DetChar/PEM to measure affects of instrument air (what we've been calling compressor noise) after this change this morning at around 8:30 am local (16:30 UTC). The compressor is not off, but now GV6 gate is fully lifted.

I will monitor the bottle pressure every hour and valve it out and compressor back in before I leave today. We are keeping a spreadsheet of bottle consumption.

WP 8460

Comments related to this report
chandra.romel@LIGO.ORG - 13:01, Tuesday 12 November 2019 (53193)
Link

Valved out bottled gas and valved back in compressor air at 1pm local.

vladimir.bossilkov@LIGO.ORG - 13:48, Tuesday 12 November 2019 (53198)
Link

So I did a little bit more looking around in the Summary pages.
The noises I am talking about here were absent in September (eg, 27th). They are: ~32 Hz and ~11 Hz
I mean ... there are countless other lines above that frequency around there that visually look slimiar, and exist looking back to September. But they do not couple to GW strain (high enough frequecny to be suppressed?)
 
In just about every single Corner-station related accelerometer in the PEM, you will see (at least) two very bright signals
[https://ldas-jobs.ligo-wa.caltech.edu/~detchar/summary/day/20191112/pem/accelerometers_corner_beam_tube/]
32Hz visible in all beamtubes
11Hz not visible in Y directions on SRTUBE and MCTUBE
[https://ldas-jobs.ligo-wa.caltech.edu/~detchar/summary/day/20191112/pem/accelerometers_corner_bscs/]
All BSC 1-3, X and Y
[https://ldas-jobs.ligo-wa.caltech.edu/~detchar/summary/day/20191112/pem/accelerometers_hams/]
All HAMS 1-6, X,  Y, Z
[https://ldas-jobs.ligo-wa.caltech.edu/~detchar/summary/day/20191112/pem/accelerometers_psl/]
PSL tables and periscope X,Y, Z
 
We are not locked yet, so I can't speak for the bottom line: the GW strain - but for the time being the noises do not appear to have changed much since 16:30 UTC, at the readout of the accelerometers.