Comment laurell-R SNF 2011-01-07 11:30:52: Leak definitely at the top cover screw at 8O'Clock

[lindaw at snf.stanford.edu]

I verified while cleaning that the screw at 8 O'Clock is definitely leaking air into the chamber.  With tape over the top cover hole, I sprayed a few drops of acetone near the outside of the screw, and the acetone was sucked into the chamber immediately.