For what it is worth....

We used to run a lot of dirty gases from an EA [lizard poop, feathers, 
soil C, etc.] on our Delta plus.  I purchased a spare ion source so 
that we had a spare to slip in and get back up and running while 
cleaning the other at our leisure.  The new ion source produced [and 
still does] a much lower slope for D/H.  Only that gas was affected.

-- 
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Steve Nelson
Associate Professor
Dept. of Geological Sciences
S-389 ESC
Brigham Young University
Provo, UT  84602

801-422-8688

"Guns don't kill people, Dick Cheney kills people."
George W. Bush:  "Decider in Chief"
"Iraq burns.  We shop."  Bob Herbert
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Disclaimer for the feeble-minded:  It should be painfully obvious, but 
the identification of my affiliation with Brigham Young University does 
not imply that the University endorses any political or otherwise 
partisan content of this message.