Recall that TC1 has an offset and that it is under-representing the actual temperature it is exposed to by 6C - 10C.  

Also while at Y-mid, I closed the exhaust valve on the turbo that is pumping CP4, closed the foreline isolation valves and opened the scroll ballast/purge plug.  This allowed room air to purge, under viscous conditions, any water that may have condensed between the scroll stages since stopping the UHP N2 purge gas the other day.  I restored the configuration after a minute or two of viscous purge.  

I used the hand-held TC meter to measure the underside of CP4's vacuum vessel (1 ft. radius around vent/purge nozzle represented by TC3) and found the average temperature to be around 65C.  It would be interesting to see if we could lessen the temperature striation we are experiencing (HOT air resides at high elevations cooler air found at lower elevations) by heating the inner LN2 reservoir using the regeneration system.