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 Thu Mar 28 2002 - 18:00:11 MST