From: Jim Peters (jim_at_uazu.net)
Date: 2002-02-15 09:31:06
Jim Meissner wrote:
> ( For some reason I do not remember having the offset voltage
> problem that Joerg is so concerned about. I used DC coupling with a
> preamp gain of 100 before the AC coupling capacitor.)
As Joerg pointed out, increasing the power supply voltages should help
compensate for the effect of DC offset voltages, and you *did* mention
that you found increasing power supply voltages helped. However, if
this makes no sense, please ignore, because my electronics knowledge
is not immense.
> I would like to hear what you found regarding electrodes, they might
> be better? What are they and how much and where do you get them?
If I were to build electrodes, I'm very much attracted to this
brass/sponge idea that you describe. When the parts are cheap, there
is much less of a barrier to experimenting.
The UK source for electrodes I found was Oxford Instruments. I tried
a few medical suppliers but they didn't want to talk to me because I
was a private individual. I contacted Oxford Instruments directly,
and they were more helpful. They gave me a number I could call for
orders in the UK. I haven't established their UK pricing yet. Here's
the number they gave me:
> If you contact our Old Woking sales administration department 01483
> 748432 they will be able to take your order on a credit card,
The electrodes are standard Ag/AgCl ones.
Right now I'm focussing on the analysis app, and I'll think about
electrodes again when that is done.
Jim
-- Jim Peters (_)/=\~/_(_) jim_at_uazu.net (_) /=\ ~/_ (_) Uazú (_) /=\ ~/_ (_) http:// B'ham, UK (_) ____ /=\ ____ ~/_ ____ (_) uazu.net
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