Hello friends,
air backgrounds are too high in our TCEA-Conflo-Delta setup, so there is a leak, but we're stuck.
- in normal conflo operation settings, Ar is about 5x too high
- with HF capilaries off, it's about 20x too high
- background goes back to normal with high He dilution (90%+)
- switiching between HFI and HFII doesn't make a difference
- background on ref side is normal
- changing TCEA conditions does not seem to make a difference
- I blew argon all over and didn't detect anything (expect near the conflo open split)
- I tapped and pulled all the capillaries in the conflo, hoping a leak from a cracked cap would show up, nothing
- the capillary to the instrument on top of the sample split was fixed/reattached with some glu before my time, I added some epoxy in case the sealing was cracked, no difference

With all this I'm thinking something could be wrong with the position of the caps in the sample split, but they *seem* ok...
Any idea before we start replacing capillaries?

Thanks for your help

Julien Foriel
Johnston Lab, Harvard U.