We measure d18O of water using the co2 equilibration method via dual inlet
on our IsoPrime. Recently, when the instrument checks maximum signal, the
signal degrades so rapidly that a stable signal is never attained,
crashing the instrument. It doesn't seem to be gas volume or quantity
because if gas is routed to the waste pump for several minutes and then
returned to the source from EITHER the sample or the reference side,
signal starts at 1.16e-8A and then quickly drops off to 4 or 5e-9A. The
bellows remain closed or nearly so, gas is routed to the waste pumps for
several minutes, and then when it returns to the source, it starts at
1.16e-8A...clearly suggesting the gas quantity did remain constant.
Suggestions? Contaminants...water? Source...filament? Thank you!
Earth and Space Sciences
University of Washington
Seattle, WA 98195
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