Hi Gregory,
On all our (imaging) systems the 'public' exposure limit for the stray field is 0.5 mT, which is always fully contained within the walls (floor and ceiling as well) of all our scanner rooms, and this should be mandatory in all (newly installed) MR/NMR-units. I have seen hard disks being affected by stray fields down to about 0.1 mT, but that is a different story. Also PMTs in neighbouring equipment are affected by very low stray fields.
73, Peter
On 7 Dec 2011, at 18:55, Heffron, Gregory J. wrote:
> Hi Everyone,
>
> We would really appreciate it if any of you could let us know what standard or rules your institution uses regarding stray magnetic fields for your NMR labs when you install a system. At our institution there is a requirement that the 1 gauss line be fully contained within the NMR room in all directions. What regulations do you have (5 gauss, 1 gauss)? This applies only to newly installed systems, not to existing ones that may have been there for many years, so you need not spend time telling us about those.
>
> Thanks very much,
>
> Greg Heffron
>
>
>
>
>
>
> Gregory J. Heffron
> Director, NMR Facility
> Harvard Medical School
> 240 Longwood Ave.
> Boston, MA 02115
> Ph:617-432-1812 Office
> 617-335-2929 Cell
> 617-432-4383 Fax
_at_ _at_
..
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| MR-Unit and CMIV Fax: (+46 10) 103-2792 |
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Received on Thu Dec 08 2011 - 11:24:08 MST