>I keep running into the same phenomena when I switch from dual inlet 
>to conflo on my DeltaV.  When I switch modes I have high mass18 
>(water) so I turn on my inlet heaters.  The signal exponentially 
>drops to background over the course of ~ 3 hours and remains there 
>overnight.  Then when the source/inlet/analyzer heaters 
>automatically turn off after 12 hours the signal goes up...turning 
>the heaters back on then increases the signal even more, and there 
>is a persistant high background.   Im wondering if the initial rapid 
>decrease  is just an electronics issue and the 18 mass is 
>masked?  If not why would the water increase by turning off the heater....

Greg Michalski, Assistant Professor
http://www.purdue.edu/eas/michalski/
Department of Earth and Atmospheric Sciences
Purdue University
550 Stadium Mall Dr.
Lafayette IN.47907