Not to be confused with surface resistance, surface resistivity is a measurement of a material’s inherent electrical resistance. For electric current flowing across a surface, the ratio of DC voltage drop per unit length to the surface current per unit width.
In effect, the surface resistivity is the resistance between two opposite sides of a square and is independent of the size of the square or its dimensional units.
To test a material’s electrical resistance, a surface resistivity meter can be used. Surface resistivity measurements are expressed in ohms/square.