Correction factor curves for square-array and rectangular-array four-point probes near conducting or nonconducting boundaries

Resistivity measurements made with a four-point probe on a sample having at least one of its dimensions small (i. e., of the order of the spacing between the points of the probe or smaller) require a correction factor to compensate for this condition. Correction factors for various four-point probe arrangements near a conducting or a nonconducting boundary have been derived and plotted for cases where : 1) the four-point probe array is rectangular and of various proportions rather than square, 2) the current points of the square-or rectangular-array probe are perpendicular to the boundary 3) the current points of the square-or rectangular-array probe are parallel to the boundary.