Today I observed an unusual phenomenon. Our company uses epoxy resin flooring throughout the building. On the second floor, when using a rough‑textured conductive rubber base electrode , the resistance measurements are consistently > 1.0×10⁹ Ω. However, when using a smooth, fine‑textured conductive rubber base electrode, the measurements are consistently around 1.0×10⁶ Ω – a difference of three orders of magnitude.
Our preliminary analysis suggests that the smooth, fine‑textured electrode makes better contact with the epoxy floor and even exhibits a certain degree of adhesion / tackiness to the surface, which significantly reduces the contact resistance and yields lower readings.
However, the puzzling part is that on other floors, which also have the same epoxy resin flooring, the measurement results are not affected by the electrode type – both rough and smooth electrodes give comparable values.
We would like to invite discussion on the possible root causes, particularly from the perspectives of floor installation/construction processes and test equipment / measurement methodology. What might be unique to the second floor that causes this electrode‑dependent behavior? Could it be related to differences in surface finish, curing conditions, topcoat formulation, contamination, or grounding practices? Any insights are welcome
