Hello all,

	In our lab we only measure hydrogen about once a year (if that) so each
time I have to refresh my memory on how to switch from CO2 tuning to H2
tuning, etc.  This most recent switch is giving me problems and I hope
someone can offer advice. The hydrogen peak shape is very similar to what we
have had in the past but the Isodat software cannot successfully do a peak
center.  It sometimes finds the peak scanning from 1000 – 3000 steps, but
never finds the peak in the opposite direction.  The filament burnt out in
the middle of the switch from CO2 to H2 but a new filament did not improve
the situation.  It appears as if the peak is too broad, in that the peak is
not well defined when doing the quick peak center.  I’ve adjusted the source
parameters countless times and even though the peaks look good in terms of
peak shape (instrument control), the peak center still fails.  I wanted to
ask if 1) anyone has experienced this before, and 2) what your “cookbook”
recipe is for tuning to H2?  We have a delta plus and the goal is simple
dual inlet measurements.  We recently upgraded to Isodat 2.0 and I believe
this is the first time we’ve attempted hydrogen measurements with the new
software.

Thanks in advance,

Joe