Originally Posted by **Cesium** I am interested in the voltage drop in the solution near different points along the electrode surface. So, I'm actually interested in the area from the middle of the inner electrode out to its edge (0 <= x <= a). I'm thinking the middle of the inner electrode should experience a smaller "effective" voltage drop since some of that voltage drop will drop over the IR of the solution. |

The voltage at every point on the inner electrode is the same, assuming we can ignore bulk resistance of the material that the electrode is made from. The fact that solution is in contact with it is immaterial. I have attached a figure that may help you see why this is - a voltage V_T is applied to electrode B and electrode A is hooked to ground. The resistance of the solution is simulated using resistors - the figure shows 5, but it could be simulated using thousands if you want. The voltage at points 1, 2, 3, 4, and 5 are all the same, and is equal to V_T, regardless of the fact that there is current flow through those nearby resistors.

Originally Posted by **Cesium** I'm a little confused by your solution too, in that when x = a, Vx = 0. |

That's correct. I didn't state it explicitly, but the potential at each point is measured relative to the inner electrode, so it ranges from 0 at x = a to V_t at x=b..

Originally Posted by **Cesium** Edit: Is this as simple as the following?
Eapplied = Eactual + I*Rsln
and Rsln = l/(c*A)
where R is the solution resistance, l is the distance between the inner electrode point of interest and the outer electrode, c is the conductivity of the solution, and A is the area of the electrode (the area up to the point of interest) |

I'm not following what you are attempting here. What do you mean by "the area up to the point of interest?"