Thank you all so much for all your responses. I have a list of things to check now.
One thing that lots of you mentioned are VT control.
The experiment ran without temperature regulated and VT was off and no high temp experiment. The experiment parameters show VT was not regulated . Unfortunately when student ran this experiment I was in the other lab. The information sent by student was he used Glide program to run HMBC Experiment, after a 1d proton exp and at the beginning of HMBC exp, the machine sent an error msg "ACD overflow" then it stopped response.
The machine was inactive when I arrived the "crime scene". After "acqproc", the sample still can not be eject out. Then after I took sample out, I saw the burned tube.
The question is could Heater on even VT is off? also the HMBC exp has been ran before with no problem.
Jennifer
> On Sep 24, 2014, at 12:19, Xiaoyan Sun <xsun9_at_ncsu.edu> wrote:
>
> Dear All,
>
> Hope you all had a great summer!
>
> I would like to ask your help to figure out what happened in my Maganet/probe. I have never seen that a probe could be burned like this way. First let me briefly describe the "crime scene".
>
> 1. A standard NMR tube was melted inside of the probe. The probe is Varian 400MHz AutoSW PFG. The tube does not broke, just melted.
> 2. A piece of broadband coil (inner coil) was fused within the glass of the NMR tube.
> 3. The shimming coil is intact.
> 4. The glass tube/connection of VT connect is intact.
> 5. Gradient is off.
> 6. HMBC experiment was ran. parameter such as: pw (11), tpwr (58), decoupling power (pwx:59 pwxleve:9.6) are all within the limit.
> 7. All components in console are all working.
> 8. Sample was ZnC-PEG, solvent was CDCl3.
>
> If you had the same experience, please let me know what your finding was.
>
> Also, any clue, input, or suggestions is appreciated. I am now clueless what could possible generate so much heat inside of the probe. If you interested to see the pictures of the tube and probe, please click the link below, you will be surprised.
>
> Probe Burned
>
> Thank you so much!
> Jennifer
>
>
Received on Thu Sep 25 2014 - 02:59:19 MST