Hi Melanie,

Not sure if this is of any relevance to shed light on the underlying question, but instead of using the floppy disk test go for the PC monitor test; i.e. see how close you can place a PC monitor to your IRMS before distortions become noticeable. This test is especially impressive with an IRMS based on an e-magnet. There is a point where the monitor is seemingly unaffected as long as one keeps the magnet constant but wait for the next magnet jump. The display goes through all manners of contortions before coming back (or not; or with colour smears; or...).


Best,

Wolfram

________________________________________
From: Stable Isotope Geochemistry [[log in to unmask]] On Behalf Of Bruce Eglington [[log in to unmask]]
Sent: 04 February 2008 17:04
To: [log in to unmask]
Subject: Re: [ISOGEOCHEM] magnetic shield between mass spectrometers?

Hi
  I have not tried shielding between mass spectrometers because tests we
performed on several mass spectrometers in our lab during the 1980's showed
that the magnet field was localised to very close to each magnet. In
addition to doing the tests with proper equipment to measure magnet field
strength, we initially tried a brute force approach by trying to demagnetise
a floppy disk. Nothing happened to the disk anywhere outside the imidiate
poles of the magnet i.e. we had to move the flight tube out of the way to
have any effect.

Cheers
  Bruce


Dr Bruce Eglington
Saskatchewan Isotope Laboratory
Geological Sciences
University of Saskatchewan
114 Science Place
Saskatoon, SK S7N 5E2
Canada
e-mail : [log in to unmask]
tel : +1-306-966-5732
fax : +1-306-966-8593
Skype : BruceEglington

-----Original Message-----
From: Stable Isotope Geochemistry [mailto:[log in to unmask]] On Behalf
Of Melanie Behrens
Sent: February 4, 2008 10:29 AM
To: [log in to unmask]
Subject: [ISOGEOCHEM] magnetic shield between mass spectrometers?

Dear all,

Has anybody tried a magnetic shield between two Isoprimes or other mass
spectrometers to avoid interference during magnet hysteresis? Is this
possible at all or is it best to place instruments as far apart as possible?

Best regards,
Melanie

--
Dipl.-Ing. (FH) Melanie Behrens

Alfred Wegener Institute
Helmholtz Center for Polar and Marine Research Glaciology

P.O. Box 12 0161                        Am Alten Hafen 26
27515 Bremerhaven                       27568 Bremerhaven
Germany

Tel.:   +49-471-4831-1396
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