Other aspects worth noting
There are several floor resistance probe configurations available on the market. Some are fitted with carbon filled conductive pads, others with conductive pads containing silver particles. Both can do an equally good job, however, it has been observed that the ones (first generation) using a silver particle filled conductive pad, are more susceptible to wear/ degradation and react with solvents like isopropanol or ethanol. As a result, due to damage or degradation, these pads will become concave or convex (depending on where the wear/ degradation occurs). (See picture to the left)
Not all of this unintended “reshaping” of the conductive rubber pad surface can be observed with the naked eye. It can be measured though, using a device that measures the electrical conductivity over a set of predefined points across the pad area. The resulting resistance should lie in between a tightly fixed range. If this is not the case, then your probe is not flat and smooth anymore.
The effect of (unknowingly) using convex or concave conductive pads, is that less contact with the specimen occurs, which results in higher resistance values. This may lead to rejection of the floor, or any other materials under test using these probes.
Eurostatgroup – Pim Dik (co-auteur) | Total Esd Solutions – Tim Maas (co-auteur)