volume resistivity (r_v)

The dc voltage per unit thickness, applied across two electrodes in contact with a specimen, divided by the current per unit area passing through the system.

NOTE 1 Volume resistivity is generally expressed in ohm-centimeters.

NOTE 2 When concentric ring electrodes are used as described in ASTM-D991, volume resistivity is calculated by using the following equation:

volume resistivity (r_v) = π × (D₁)² × R/4T

where

D₁ = diameter of inner electrode or disk;
R = measured resistance in ohms;
T = thickness of specimen.

References