Hiya Simon...congrats on getting Europa back in action...hope all is well
with you these days.  Weather is getting cooler here, the fall colors are
past their peak but still nice -- SKIING SOON!!!

Now did you think I'd just drop you a plain old note without some tech.
questions?

The ANCA-SL is acting up a bit...symptoms:

1. the flow rate has dropped off about 4mls/min from normal
2. N numbers are a bit wild here and there
3. Carbon peak has a long drawn out tail, so much so that it necessitates
making the integration window 110sec longer!!  BUT, the numbers are
fine!??!?!  odd...
4. background seems a bit high at times.

So, I checked for leaks...can't find any (YET!).  Changed rxn and red.
tubes, water trap, all seals and o-rings on these items.  Checked all the
fittings for tightness...nothing seems to fix it.   I purged the O2 supply
lines.  I baked the GC overnight at 120c twice, now trying 200C for a few
hours...(has anyone had their GC column go bad on them? -- not BLOODY
likely, eh?).  Ballasted the pumps - this brought down the background some.
By messing with the integration window settings I can get closer to the
known numbers for our references - but I shouldn't have to do this.

Seems like its an atmospheric leak somewhere -- we are waiting on some
parts from you (columns et al.) and I'll do another fresh build up on it.
Maybe one of the tubes has a hair-line crack in it is all I can think of
now...

Any other good ideas???

Also, can we get a replacement "U"-shaped bit of 1/8" stainless tube with
the cap for the reduction column egress???  Ours is getting quite torqued
from use (can see spirals in the tube above the cap part!!).  Let us know...

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thanx!


Cheers!

C

Christopher G. Alpha
Cornell Laboratory for Stable Isotope Analysis
Boyce Thompson Institute for Plant Research
Tower Rd.
Ithaca, NY 14850
VOX: 607.254.1227
FAX: 607.254.1382