We have a problem with our Conflo-III system, which is attached to a Delta
Plus XL. When we turn on any of the reference gases (CO2 or N2), we get a
large signal (>14 volts).  My first thought was that the pressure was too
high. We decreased the pressure using the gauge in the Conflo unit, but
there was no luck. We checked the pistons and the distances of the
capillaries inside the open split glass cell when they are on and off, and
all of them are ok.  I also thought that we were not getting any or low flow
of helium. We measured the flow of the helium stream entering the open split
glass cell and it is what is expected (~2 ml/min).  We even disconnected the
EA to see if somehow the problem was with the EA, but we still see the same
problem.  What makes this problem so particular is that when we turn on the
CO2 reference gas we only get a large signal on mass 44. Masses 28, 40, or
18 only show a slight increase. When we turn on the N2 reference gas we only
get a large signal (>14 volts) on mass 28, not on any other mass.  I ran out
of ideas, so I would  really appreciate any help.

Thanks,

German