Head flow rates for heads 1-4 for the past 6 hours.  The hiccups for the first 40 or so minutes
are due to starting and restarting the crystal chiller as we checked for leaks.

Also shown are the flow rates for the front end laser and the power meter circuit.  These were
previously disconnected when we were trying to debug what was causing the chiller to trip so often.
Now that all four sensors in the heads have been replaced, they are not likely to be a cause of
a trip unless there are still stray bubbles working their way through the system.