Dear AMMRL members,
Can anyone offer some advice?
We have a Varian Inova 500MHz NMR spectometers with a pfg triple
resonance probe.
Normally we have obtained lineshape well within specs, but in a 3 week
period we have noticed an increase in the base of the lineshape peak.
(specs non-spin 0.65/6.00/12.00, our current specs 0.50/29/98). It is
still nicely symetrical but a very broad base. Probe placement is fixed.
What we have tried:
Shimming on the X3,Y3,Z3X,Z3Y shims
Setting all x,y shims to 0 and shimming
Automatic FID shim for X,Y shims
Cleaning magnet bore in case of contamination
Is there anything else we should try?
Could it be a hardware problem (shim coils, connections) ??
Any suggestions appreciated.
Sandra
--
Sandra Chapman
Professional Officer
Department of Chemistry
University of Wollongong
Northfields Ave
Wollongong NSW 2522
Phone 61 2 42213473
Fax 61 2 42214287
Received on Mon Oct 11 2004 - 09:31:21 MST