Hey all,

A little late in coming to this discussion (I read in digest mode), but for 
what it's worth, the HV trips off to 0.34kV here as well, but only on my 
Advantage (not on my Plus or XL).  Will be curious to see what happens on 
my new Delta V.  The problem only occurs here about once a week, though it 
is somewhat unpredictable.  As Jason said, when running at full capacity, 
it only effects one sample out of several hundred, and during a dual NC 
run, can correct itself at the next slow-magnet jump.  Despite its 
debatable "infrequent" occurrence, it is still very troublesome, especially 
when having to explain to a client why that really important data point for 
that one-time-only sample was lost.

Here's hoping Thermo figures something out soon.

Good luck to you all in the meantime.
Cheers,
Rick


>Date:    Wed, 30 Nov 2005 11:21:40 -0500
>From:    Linnea Heraty <[log in to unmask]>
>Subject: Spontaneous HV turning off on Thermo Delta XP
>
>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

Richard (Rick) Doucett, Ph.D.
Associate Director, Colorado Plateau Analytical Laboratory
Northern Arizona University
Flagstaff, AZ, 86011-5640

Tel: 928.523.0967
Fax: 928.523.7500
Email: [log in to unmask]
Stable Isotope Lab Website: http://www4.nau.edu/cpsil/