Yes, this is something that we have also experienced with one of our Delta 
XP instruments and have yet to resolve. I'd also be interested in any ideas 
or thoughts that people have about this.

Ian

--On 30 November 2005 11:21 -0500 Linnea Heraty <[log in to unmask]> wrote:

> 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



-------------------------------------------------------------
The information contained in this email
may be subject to public disclosure under
the Freedom of Information Act 2000.
Unless the information is legally exempt
from disclosure, the confidentiality of this
email and your reply cannot be guaranteed.


Dr Ian D. Bull
Organic Geochemistry Unit (OGU)
Bristol Biogeochemistry Research Centre
School of Chemistry
University of Bristol
Bristol  BS8 1TS
United Kingdom

Tel.        +44 (0)117 9546967
Mob.      +44 (0)787 6245948
Fax.       +44 (0)117 9251295
Email      [log in to unmask]
Website  www.ianbull.me.uk

"I left in love, in laughter, and in truth,
and wherever truth, love and laughter abide,
I am there in spirit."

                    - Bill Hicks (1961-1994)
--------------------------------------------------------------