Published Online: 27 October 2008
Page Count: 8
Woolley, David E.
Saint-Gobain High Performance Materials, Northboro, MA
(Received 21 January 2008; accepted 19 August 2008)
Electrical resistivity of moderately conductive solids is determined according to ASTM D4496  using the four-probe method. The ideal specimen is long, thin, and of uniform cross section and composition. The ideal configuration of current electrodes is uniformly covering the opposite ends of the specimen to create a current path in the axial direction through the specimen. The purpose of this study is to determine what errors may arise from using nonideal specimen size or current-electrode configuration. The dc four-point resistivity test is simulated using a finite element (FE) model, which yields the electric potential distribution in the specimen and the electric current. Specimens in the form of bars and cylinders are studied. Simulations show that the calculated resistivity will be false-high when the current electrode is a band around the outside of the specimen or strip on one side of the specimen and when the parameter (R or H)/((Lo-LiR H Lo-Li
Paper ID: JTE101676