Hello,
The source of information is personal experience from when
I was Manager of Engineering at Nicolet and later
GE NMR Instruments. GE had several installation problems
when mass specs were nearby. Upon investigating it was found
that the NMR instruments needed to be moved after the
interference was discovered. GE's field service people
were upset at having to do a de-installation and
re-installation after meeting all specs.
This happen twice, after which GE got smarter in
describing the installation environment specifications.
On the systems in use at that time it seemed that
50 feet was not enough to prevent the mass specs from
creating problems with 2D experiments but that 100 feet
was enough. EXTREME care needs to be taken with steel beams
overhead or in/under the floor because these can be
flux channels and make the interference travel MUCH
farther.
Similar interference problems were observed between high
resolution systems and animal and whole body MR systems
because of the gradients they use. GE's shielded gradients
were much less of a problem, though pointing the bore
of a horizontal MR magnet in just the wrong way causes
similar problems.
As was noted in my first response, using shielded NMR magnets
will GREATLY reduce this type of interference problems.
woody_at_acornnmr.com
> -----Original Message-----
> From: Xinghao.Wu_at_aventis.com [mailto:Xinghao.Wu_at_aventis.com]
> Sent: Tuesday, February 26, 2002 10:02 AM
> To: woody_at_acornnmr.com
> Subject: RE: magnets and mass specs
>
>
> Hi,
> It's interesting to learn that the mass spec can have long
> distance interference. We are going to relocate our MS lab
> which will be ~80 feet away from NMR (11 T non-shielded
> magnet) lab. Since it's not too late to change the plan,
> could you provide more information or source of the information?
>
> Thanks!
>
> Xinghao D. Wu, Ph.D.
> Advanced Instrumental Analysis
> Aventis Pasteur
> Discovery Drive
> Swiftwater, PA 18370
> 570 839 4313
>
> > -----Original Message-----
> > From: Woodrow Conover [SMTP:woody_at_acornnmr.com]
> > Sent: 25 February, 2002 8:08 PM
> > To: ammrl_at_chemnmr.colorado.edu
> > Subject: RE: magnets and mass specs
> >
> > Hello,
> >
> > Outside reasonable distances (10 feet), the mass specs
> > will probably have no problem with the static field
> > from the NMR magnets. This is even more true since you
> > are considering shielded magnets.
> >
> > However, the mass specs often have rapidly varying
> > magnetic fields when they are scanning. These sweep
> > fields from the mass specs can interfere with NMRs
> > for large distances (> 100 feet in some cases). This
> > interference would be greatly reduced by shielded
> > NMR magnets but it is an area to investigate before
> > locating mass specs and NMRs in the same general area.
> >
> > woody_at_acornnmr.com
> >
> >
> > > -----Original Message-----
> > > From: Valerie Robertson [mailto:vroberts_at_uoguelph.ca]
> > > Sent: Monday, February 25, 2002 12:02 PM
> > > To: ammrl_at_chemnmr.colorado.edu
> > > Subject: magnets and mass specs
> > >
> > >
> > > BlankDear Colleagues,
> > >
> > > We are in the planning stages of a new chemistry building,
> > > which will include large NMR and Mass Spec facilities. The
> > > Mass Spec people are quite concerned about the impact of our
> > > magnets on their equipment. We're planning on some big
> > > magnets, but they will be shielded. Could anyone out there
> > > with some actual experience let me know if they've
> > > experienced any problems - how close things could get and
> > > still work etc. Any help much appreciated -
> > >
> > > Cheers
> > > Valerie
> > >
> > >
> > >
> > > **********************
> > > Valerie Robertson
> > > NMR Facility Manager
> > > Department of Chemistry/ F&SM NMR Centre
> > > University of Guelph
> > > phone: (519)824-4120 x8914
> > > fax:(519)766-1499
> > >
>
Received on Tue Feb 26 2002 - 13:28:14 MST