RE: peak splitting

From: Hsin Wang <wang_at_postbox.csi.cuny.edu>
Date: Fri, 29 Mar 2002 10:24:12 -0500

Sorry to hear about your trouble with the magnet. Our Varian 600, it was a
UnityPlus then before upgrade, had its Z1 drifted out of range within 2-3
years of installation. Varian came to recharge the Z1 cryoshim and it has
been good for 4-5 years now. We have not noticed any problem with z0. I
wish you good luck in resolving this issue and would like to hear other's
experiences.

Hsin

--
Hsin Wang, Ph.D.
NMR Facility Manager
College of Staten Island
2800 Victory Boulevard
Staten Island, NY 10314
Phone: 718-982-3809
Fax: 718-982-3910
Email: wang_at_postbox.csi.cuny.edu
  -----Original Message-----
  From: Wei Li [mailto:wli_at_utmem.edu]
  Sent: Sunday, April 28, 2002 4:31 PM
  To: ammrl_at_chemnmr.colorado.edu
  Cc: bmoore_at_utmem.edu
  Subject: peak splitting
  Dear friends,
  We seemed to have a problem with our Z1 in our new Inova 500. Here is what
we found: we took 1D proton spectrum every hour for 15 hours with either
lineshape or sensitivity sample. The temperature is regulated well and lock
is not saturated. To our surprise, we found the initially nice siglet split
and shifted after a few hours. Our magnet drifted about 6Hz/hour, and I am
suspecting the large Z0 current change affect the Z1 and mess up with the Z1
shims. Also our Z1 constantly drift to larger values, and Varian had to come
to adjust the cyroshim recently to prevent room temperature Z1 reach its
extreme.
  I am curious to find out if anyone has seen such behaviour before, and if
you have, how could you do any long time 2D or 3D experiment, since after a
few fids, the peaks position will shift and split?
  Any comment will be highly appreciated.
  Regards
  Wei Li

Received on Mon Apr 01 2002 - 09:29:50 MST