Vt problems

Andreas Kaerner (andreas@chem2357.ucr.edu)
Tue, 6 Jan 1998 22:44:13 -0800

We just ran into a similar problem, our Inova was nice enough to pickle/boil our
peptide sample in H2O. The VT controller thought it was -65 C when in fact it
was 25 C, so it adjusted the actual temp to about 115 C. We tracked it down to
broken pin in our VT cable connector at the probe. I recommend pulling apart
the VT cable connector and carefully checking the pins, even if a continuity
check is OK. In addition, if the connection is really bad the VT will read
+999 C.

Good luck,

Andreas

On Jan 6, 12:07pm, lew cary wrote:
> Subject: More Vt problems!
> When I walked in Monday, the unity500 had , the day before, toasted a
> sample! Overnight, the temp had gone up enough to pop the cap on a cdcl3
> sample, and evoporate the solvent, and cover the top of the spinner with
> solid sample. With slight cleanup every thing seems normal.
> We always run the vt on and at 25C. One probe has an intermittant
> with the thermocouple. The cable is wonky, but with care works with all
> other probes. The symptom is always the same: the appearent temp. goes to
> max., but the sample is not heated.
> My question is: how could a thermal runaway have happened? Over
> temp shuts off the heated in all cases that I have seen. No one was there
> Sunday, of course.
> What a great way to start '98, Lew
>-- End of excerpt from lew cary

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Andreas Kaerner
Department of Chemistry
University of California, Riverside
Riverside, CA  92521
andreas@chem2357.ucr.edu
andreas@habanero.ucr.edu
dlr@woodward.ucr.edu
(909) 787-3573
(909) 787-4713 (fax)


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