J. Oberling, R. Schofield
At Robert's request I lowered the flow rates of the PSL cooling circuits by ever so slightly opening the bypass valve in the chiller room. Our target was to get the flows close to 1.5 lpm. In the past, the flow meters were happy with flows at this level (unlike when we were running with a flow closer to 1.0 lpm and the meters became very glitchy). Robert will assess how this small change effects PSL table motion; I will keep an eye on the flow meter readings to see if they become glitchy again.
Flow rates before change:
Flow rates after change:
Attached are the relevant flow rates for the last 2 days; the change in flow is clearly seen. What looks like a single glitch shortly after the change is actually not. While we were in the PSL enclosure Robert requested that we slightly open the bypass valve on the manifold (the valve on the old HPO crystal cooling circuit) for a few seconds to release any trapped air bubbles. This is the cause of the apparent flow glitch, not an actual glitch in the reading from the flow meters. Therefore, after >24 hours there have been no glitches in the flow rate. I will continue to monitor this, but so far everything looks stable.