We're currently trying to get our GasBench up and running after a long period of inactivity. We've plumbed the 0.3% CO2 in He line directly into the GC column (and saw CO2!) and into the bulkhead that normally holds the sampling needle capillary (and we don't see any CO2). The issue seems to be with the valco 8-way valve and leaks initiating with it. We now have the water trap plumbed into port 5 on the 8-way valve so it feeds directly into the GC in load mode, but again see nothing. Our helium leak detector is showing major leaks at both screws, but the ferrules are biting the capillary well in both cases and we've remade the connections a few times to no avail. We're currently using FS1.5 ferrules for fused silica running in and out of the 8-way valve and ZRF1.5 ferrules for the silcosteel. Have other folks had this issue before? Are there other ferrules we should be using for the 8-way valve? Thoughts or suggestions are highly appreciated!
NASA GSFC | UMBC | CRESST II
Scott Wieman, M.A.Planetary Environments Laboratory, Code 699