[Gerardo, Chandra, Kyle, John]

• Vented vertex in two hour span. Purge air dew point measured between -35degC and -43degC before, during, after. Leaving the purge air valves closed overnight (pressure currently reading 834 Torr, or 1.4 psi over sea level atmospheric pressure (weatherbug reports 30.01" (764 Torr) barometric pressure)). We also removed all but four bolts from BCS3 & HAM4 doors.
• Cetec valve on IP1 is leaking. See attached trend of all four IPs that were isolated in vertex. Kyle and I went back to tighten all four valves; was able to turn each by 1/4 to 3/4 turn. These valves need to be replaced!
• Noticed that the pressures in the adjacent volumes - X&Y beam tube manifolds - show opposite trends in pressure change after hard closing GVs 1,2 and soft closing GVs 5,7. The X side rises and Y side decreases. You might expect it to rise due to the loss of cryopump action, or you might expect it to fall due to a 2500 l/s IP pumping on a relatively small, vacant space. Maybe one IP is more effective than the other, or maybe we have.....................a vacuum leak. Kyle prepared the area for leak checking. However, looking at a year trend, the CC gauge on BSC2 shows continual decrease in pressure. We don't fully trust these two new full range hot ion gauges that exhibit odd behaviors in trending. They seem overly sensitive to water vapor. We first noticed this when the temperature in LVEA was increased months ago. To help troubleshoot, applied 5 psi more pressure on soft closed GV 5 piston (y arm) to test whether the o-ring was in full contact. Will trend pressures tomorrow.
• RGA scan was taken this morning before vent preparation. Will attach in a separate log entry.