Chris S., Gerardo M., Kyle R.

We put the north door back on BSC10 this afternoon.  Particles counts were < 100 for the displayed sizes at the time the soft cover was removed. 

Inspection revealed two areas of missing viton from the outer O-ring.  Viton was not stuck to the door in the corresponding area of the door flange thus indicating that, most likely, this had happened in the past.  Since this outer O-ring had been leak tight leading up to this most recent door cycle, we went ahead and reused this blemished O-ring -> but helium leak tested this shortly after pumping down the annulus volume - just to be sure :)

Measured dew point of purge air entering the Y-end was -45C and exiting was -32C (just prior to start of pump down).   

With the Y-end vacuum volume having been "blown down" to atmospheric pressure and 15 minutes after starting the pump down I noticed PT410's indicated pressure was >820 torr -> Gerardo was then able to adjust the "ATM" potentiometer on PT410 such that it then agreed with the pirani gauge at the turbo inlet.