Re: Grounding Electrode
>Graphite may not be an ideal electrode for grounding purposes.
>It has a relatively high resistance. I believe pencil graphite
>is actually a composite with clay and I wonder if it would get
>soft and mushy in water.
It's true that graphite has a higher resistance than metal, but that
additional resistance is insignificant compared to the resistance of the
water. Don't use pencil lead, use real graphite, it is chemicaly inert in
this application. You can use a noble metal, but graphite should be easier
to find and cheaper than noble metal rods.
Aluminum has great conductivity, but aluminum oxide is an insulator. The
oxide forms immediately upon exposure to air. The oxide will increase the
resistance to the water but it will still provide enough conduction to
function as an electrode. Long term, the aluminum will probably corrode.
p.s. a stainles steel table knife would work!