Hi Linnea,

we've noticed a similar problem which occurs about once/week. 
Generally speaking we are operating both N and C analyses, and if the 
trip occurs, e.g., during the N part of the analysis, we lose the N 
data but the system corrects itself when it loads the parameters for 
C (and vice versa).
Thermo have indicated that the problem possibly lies in the source 
control board or is caused by power surges (unlikely, as we have a 
voltage stabiliser in between), but so far, no conclusive solution.
As it affects one in every thousand or so samples it hasn't (so far) 
worried us greatly.
Sorry this isn't very helpful, but you're not alone.

Jason






>Hello Isotope World
>
>On our Thermo Delta Plus XP, the HV has been turning off at 72- to 96-hour
>intervals when running in continuous flow mode.  The HV will trip off and
>the monitor will display 0.34 KV in the HV textbox.  Thermo service
>personnel kindly provided a cure that consisted of lengthening the capillary
>to the mass spectrometer to reduce the amount of gas entering the source.
>This cured the tripping off of the HV, but resulted in a substantial
>decrease in sensitivity (at least a factor of 2), and I can no longer
>analyze small samples.
>
>Has anyone else experienced this phenomenon and found a solution that does
>not result in substantial loss of sensitivity?
>
>Can anyone reccomend a good therapist?
>
>Many Thanks and Happy Isotope-ing!
>Linnea


-- 
****************************************************

Dr. Jason Newton
East Kilbride Node Manager
NERC Life Sciences Mass Spectrometry Facility
Scottish Universities Environmental Research Centre
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G75 0QF
UK

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5th International Conference on Applications of Stable Isotope 
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