You can isolate the problem partially by seeing if you have similar
jumps when in current control mode. If you do, then it's in the magnet
controller and not the Hall probe circuitry.
In my experience with a very old 215, the biggest sources of noise for
the magnet were 1) the main power on relay; and 2) the range changing
reed relays. For 1), I replaced the mechanical relay with a solid state
device. For 2) I removed all the old reed relays, put in sockets and put
in new relays.
Chris
Jürgen Sültenfuß wrote:
> Dear Noble Gas colleagues,
>
> our magnet control unit of our MAP215-50 makes trouble. We are pretty
> sure that the voltage provided by the pre-amplifier of the hall sensor
> jumps by about 1% in very short periods a few times during a day. So,
> either the hall sensor or the pre-amplifier causes this effect.
>
> We changed a number of plugs and capcitors yet and checked all solder
> connections.
>
> Could anyone give a hint on what else we should look for.
>
> Would anyone sell a hall sensor plus pre-amp?
>
> Could anyone suggest a company which engineers these devices? We wish to
> have about 1V for 100mT with a resolution of 0.1µT.
>
> best regards
> Jürgen
>
--
Chris M. Hall, Assoc. Research Scientist
Dept. of Earth and Environmental Sciences
U. of Michigan
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