[meteorite-list] Magnet Care

From: rochette <rochette_at_meteoritecentral.com>
Date: Thu Apr 22 10:10:10 2004
Message-ID: <a05100302bac9ed41352e_at_[193.248.146.214]>

>Hello List I was looking at a magnet that I have for searching
>meteorites and I found out that is no longer powerful. Its a medium
>sized magnet, but when I had it new it was a very good magnet and
>after a year or two it became weak=A1, does anyone know why this
>happens?, do you have to take care of the magnet? or what?
>
>Thanks list, goodbye=A1
>
Well was it a "classic" low cost magnet (ferrite) or a high power
rare earth magnet? How much did you pay for it? As every product, the
less you pay, the less it gives you... A classic magnet demagnetize
itself with time, especially if you make it work often or try to play
with another magnet, facing each other the repelling poles; a rare
earth magnet should not demagnetize whatever magnetic field it sees
(apart extreme ones that can be found only in specialised labs).
However it is very sensitive to temperature (again depending on the
quality; even among those rare earth magnets there are plenty of
different qualities). So if you hunt in the desert, do not leave it
burning under a windshield, keep it with the beer bottles....
Depending on the quality of manufacturing, it can already suffer
above say 80 Celsius. The temperature problem is also of concerns for
the low cost ferrite. The ferrite could be remagnetized with a rare
earth magnet (though it can be dangerous for your fingers).

-- 
Pierre

Received on Mon 21 Apr 2003 02:49:54 PM PDT