[meteorite-list] Magnet Care

From: rochette <rochette_at_meteoritecentral.com>
Date: Thu Apr 22 10:10:11 2004
Message-ID: <v04003a01baca9aad1de1_at_[193.49.98.39]>

>In a message dated 4/21/2003 2:56:15 PM Eastern Daylight Time,
>rochette_at_cerege.fr writes:
>
><< after a year or two it became weakĄ, does anyone know why this
> >happens?, do you have to take care of the magnet? or what? >>
> Just in case you didn't get this information, all magnets
>should be stored against a piece of metal. Never leave a
>magnet just sitting around. The piece of ferrous metal that
>is kept against the magnet is called a "keeper" because it
>"keeps" the magnetic lines of flux from weakening due to
>the slow disalignment of the magnetic domains within the
>magnet. The other two things that will kill a magnet or cause
>it to lose it magnetic strength are "heat" and strong "vibrations"
>such as from being dropped too many times. Watch out for
>those super strong magnets used in old computer hard drives.
>They will take a chunk off your finger in a heartbeat if two of
>them decide to come together while your finger is in their path.
> I hope this has been of some help.

Thanks for these precisions. May be you should post them on the
meteorite-list, not only to me! By the way the above message was writen by
Rafael Torres; not me. I also think that the need for keeper does not
concern rare earth magnets. But for ferrite I totally agree. The use of a
keeper in more a matter of security for rare earth: if you store such a
magnet free to move it is much more dangerous than if its attached to a
fixed steal mass...


Pierre
Received on Tue 22 Apr 2003 03:14:19 AM PDT