Today I leak tested the entire Vertex RGA assembly simultaneously via encapsulating all of the components within a single bag and while the Cal-Gas isolation valves were open.  The motivation for this is the result of having detected Argon in the RGA scan but not having been able to find a leak to atmosphere via testing the joints individually.  Six bag penetrations were necessary (the 2 1/2" Vertex isolation valve, the pump port used to connect the leak detector, the pump port isolation valve, two lines for the two O2 sensors used and a line for the helium) and these were sealed off as best as could be done via tape.  The helium line entered the bag at the top of the bag and the two lines for the two O2 sensors (w/internal pumps) entered the bottom of the bag.  A very large (excessive) volume of helium was applied and a large flow could easily be heard as could the obvious inflation of the bag etc. (recruited Chandra to witness this spectacle!).  No response was observed at the LD during the application of helium.  An external fan sitting on the floor was utilized to keep helium from entering the LD's exhaust.  The helium baseline was off scale low during testing.  Also, the external helium calibration bottle was valved-in prior to changing the test conditions or cycling any internal valves to demonstrate helium sensitivity/calibration and show that the mass spec. was sampling at the test port.  

Note:  Both of the O2 sensors used had expired and non-functioning chemical sensors.  Both displayed on error to this effect upon startup but then displayed believable values of 20.2% O2 and 20.4% O2 after the errors were cleared.  I demonstrated their non-functioning status via exhaling into the inlet tubes and noting that the %O2 displayed did not react.  Thus, I could not measure the O2 concentration at the bottom of the bag but they still acted as pumps and provided an escape for the helium displaced air.