Many thanks to all who replied. A number of points stood out:
1. Shimming and spinning will be affected. Re-shimming will
be required for a temperature change of any size. Air flows
may require adjustment to maintain spinning. Some Bruker
users are in the habit of venting part of their spinner air
during vt work.
2. Probe damage may occure due to cracking at low temp,
or melting at high temp. More recent probes with provision
for body or cooling air are less at risk. Some users vent
room temp air into their bore pipe at the top of the probe to
protect the shim coils from hot/cold air.
3. The probe can be close to a magnet 'O' ring. Repeated
vt work can cause these to fail resulting in a quench. I didn't
know about this. Ouch!!!
4. Plastic tube should not be a problem, as the air in it is at
room temp. Of course, some manufactures use it for vt exhaust or
route spinner/eject/bearing air from the top of the magnet stack,
past the probe.......
Vygon is not recommended above 100C.
Hope this is some help.
Andy
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Dr. A.J.Rous Phone +353-1-7062442
Chemistry Department, 7062133
University College, Fax +353-1-2837873
Belfield,
Dublin 4, E-mail andy@fiachra.ucd.ie
Irish Republic
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