Hi Art,

I had a similar problem with one of the reference gases in the ConFlo II.
The reference capillary was pulled out of the open-split because the tip had
broken off.  

There are extra solenoids in the ConFlo II that you can use.  The additional
solenoids have active address codes you can switch to in order to
functionalize the piston driving the He-dilution capillary.  The address
codes are changed in the "Isodat Configuator" application.

Mark Haught

-----Original Message-----
From: Stable Isotope Geochemistry [mailto:[log in to unmask]] On Behalf
Of Arthur T Kasson
Sent: Wednesday, May 14, 2008 3:33 PM
To: [log in to unmask]
Subject: Re: [ISOGEOCHEM] Conflo II issue

Hi everyone,

I am curious if anyone has seen similar symptoms in their Conflo system
before?

We have a NC2500 EA hooked up to a Delta Plus IRMS via a Conflo II.  We
currently have our ISODAT EA method setup to analyze both N2 and CO2 (which
of course requires a helium dilution after the N2 to CO2 jump).

My problem is that recently the dilution may or may not work during a sample
acquisition.  This happens approximately 3-10 times in the course of a 100
sample analysis.  My first thought was that the He capillary was loose but
it is not.  My second thought was that the piston controlling the
up-and-down movement on the He capillary fitting was failing (undetermined
at this point).  Another thought I've had is that the solenoid controlling
the piston is going bad (also undetermined).  My last thought is that there
is a problem in the ISODAT software when the software tells the Conflo to
put the dilution in the down position. I should mention that the Conflo unit
in question is 11 years old.

Before I start swapping solenoids and taking things apart I wanted to check
with the list to see if anyone has done troubleshooting like this before
and, if so, the steps taken to determine the source of the problem.

Thanks for your help.

Art
--
Art Kasson
Cornell Isotope Laboratory
Dept Ecology and Evolutionary Biology
E440 Corson Hall
Tower Road
Ithaca NY 14853 USA
Phone: 607.254.1382
Fax: 607.255.8088
COIL website
http://www.cobsil.com
Isogeochem website
http://www.isogeochem.com