Flat 4-point probe on a circular sample

gboff21

In measuring of the resistance of a superconductor, we are using a four=point probe to determine the voltage. We have a circular sample with a non-negligible thickness and the 4 probes are lying flat on it.
Looking at http://www.fourpointprobes.com/4-point.html, our experiment is the same except that our probes are lying straight across the face of the sample instead of just touching with tips.
Will this affect the equation ρ=π/ln(2) * tV/I?