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Reports until 13:55, Friday 30 September 2016
LHO VE
chandra.romel@LIGO.ORG - posted 13:55, Friday 30 September 2016 - last comment - 16:45, Friday 30 September 2016(30108)
CP4 experiment
Overfilled CP4 again:

1. Opened exhaust bypass valve
2. Doubled LLCV (66% open)
3. Took ~17 min. to fill reservoir from 92% to 100%.
4. Took another hour to see LN2 pour out the exhaust. 
5. TC 252B did not respond to temp. change (and I broke the other one yesterday)
6. Set LLCV to nominal at 32% open in manual mode after the overfill
7. Would like to see how long it takes CP to recover to 92% at nominal LLCV (but may not happen this time since it's the weekend)

I used the borescope to look at the TC junction on the exhaust to see if it's measuring the pipe or the fluid flow. I couldn't see much but I suspect it's measuring just the pipe since the time delay on CP3 is long and temps never drop below -12degC on CP3 (response is faster when heating pipe with heat gun). 

I would like to drill and tap TCs directly into the pipe and use the existing signal lines to measure a more direct temp. for CP3 automation.

Images attached to this report
Comments related to this report
chandra.romel@LIGO.ORG - 13:59, Friday 30 September 2016 (30109)
Attached is temp and pressure trend for a CP3 overfill
Images attached to this comment
chandra.romel@LIGO.ORG - 16:45, Friday 30 September 2016 (30117)
CP4 is now in PI mode with lower limit set to 32%. Need to set this back to 20% on Monday. Want to see how long it takes to fall to 92% full at this nominal value.
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