Hi,
I'm helping colleagues to design a RF (13.56MHz, a few kW) electrode and we argue about the water cooling.
In the current design, normal tap water is in direct contact with the electrode, flow in a plastic tube and then in a metallic tube. We dissagree on if we should consider water as a conductor (with resistance of 20-200 Ohm/m) or if it should be considered as a loosy dielectric.
My consern if it is to be considered as a conductor is that if the plastic tube is too short, the impedance of the water line to ground will partly short the electrode to ground of strongly modify its impedance.
Some colleague are saying that a minimum of 1.2m is necessary but they can't really tell me where they hear this. Any reliable source of information would be helpful to settel this debate.
Thanks,
Vereth