Journal Published Online: 27 October 2008
Volume 37, Issue 1

Simulation of Four-Point Test for DC Electrical Resistivity of Moderately Conductive Solids—Error due to Nonideal Specimen Size and Current Electrode Configuration



Electrical resistivity of moderately conductive solids is determined according to ASTM D4496 [1] 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-Li)/2) is greater than 0.5, where R is the radius of a cylindrical specimen, H is the height of a bar-shaped specimen, (Lo-Li)/2 is the distance between a current electrode and the nearest potential electrode. The magnitude of the error reported in this study is on the order of the error that can arise due to errors in measuring dimensions of the specimen.

Author Information

Woolley, David
Saint-Gobain High Performance Materials, Northboro, MA
Pages: 8
Price: $25.00
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Stock #: JTE101676
ISSN: 0090-3973
DOI: 10.1520/JTE101676