Had bagged entire RGA assembly previously -> Removed 1.5" O-ring valve (redundant valve in series with 1.5" UHV valve) and installed turbo in its place.  Backed turbo with leak detector.  Opened 1.5" UHV valve to combine detector with RGA volume.  Helium line penetrated bag at top while O2 sensor (with internal pump) penetrated bag at bottom.  No flow meter on helium but set to "significant" flow rate.  O2% fell from 20% to 1.6% over 10 minutes.  No leaks detected with helium baseline holding @ 1.2 x 10-9 torr*l/sec or so throughout the helium application -> Once convinced that no leaks were present, I closed the 1.5" UHV valve and "cracked" the isolation valve of the external calibrated helium leak and observed the expected response; thus demonstrating that the mass spec. was sampling the test port during testing.  

Installed 5 of 6 heat tapes on RGA assembly in preparation of baking it out at the next available opportunity.

Note to self: The isolation valves for the Nitrogen and Krypton calibration gases were closed during this testing so the two "factory" double-sided mini-conflat joints did not get tested.  Also, I noticed after shutting down and decoupling the leak detector etc. that the factory 2.75" CFF joint between the RGA analyzer and its protective nipple showed a crescent shaped gap.  All of the joints tested in this excercise (12 or 13?) where ones that I bolted and are "metal-to-metal" and won't change with with baking.  This sole gappy joint could leak following a thermo cycle so I will "cinch" it up and leak check it along with the two double sided joints that I missed before baking.