Arnold:

We have a Isocarb that was attached to our Optima about a year ago and we
have had similar problems with sample spillage out of the tin boats due to
the action of the stepper motor, but only when we push the capacity of the
boats by analyzing finely powdered carbonate-poor sediment and soil samples
of more than about 1500 micrograms.  Below this amount, we generally
experience no problems, unless the materials is fairly coarse-grained.  100
microgram samples of NBS-19, which is fairly coarse-grained, stay in the
tin boats.  We haven't analyzed any forams yet.  Sounds like the action on
your stepper motor is rougher than ours, for what it's worth.

Steve


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Stephen S. Howe                  Office:  (847) 491-8180
Northwestern University          Stable Isotope Lab:  (847) 491-8182
Dept. of Geological Sciences     Geochemistry Lab:  (847) 491-8184
1847 Sheridan Road               FAX:  (847) 491-8060
Evanston, IL  60208-2150         e-mail:  [log in to unmask]
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