0004 hrs. local -> Arriving on site to start CP4 watch attended "owl" shift. Working alone with Chandra R. as designated "phone buddy". Won't be doing much other than ensuring scroll pump doesn't shut down due to hydraulic lock as the result of the water vapor laden gas load as CP4 warms and off-gasses. Brought the camper-van so look for me to be at Y-mid VEA, my office or in my van (listening to 70's era rock or conservative radio :)
Will make a comment to this entry to update CP4 status or when leaving the site.
kyle.ryan@LIGO.ORG - 04:54, Friday 16 February 2018 (40571)
As the attached graph indicates, the source of gas went away at about the same time the pressure alarm threshold was exceeded. To justify my visit, I did two iterations of 1)closing the turbo exhaust valve. 2)setting the foreline isolation valve setpoint to 950 Torr (maximum allowed value). 3)cracking open the foreline connection at the turbo exhaust valve (allows the scroll pump to pump viscous room air and blows out condensed water from between the two scroll stages). 4)restoring isolation valve setpoint (now 5 x 10-2 Torr).
0500 hrs. local -> Leaving site now.
attached alarm log for this event
Glad to be back in the safe zone! (for now)