Evaluation of Measurement Uncertainty of Fabric Surface Resistance Implied by the Van der Pauw Equation

This paper presents a method for evaluating measurement uncertainty in the situation when the function of the measurement model occurring in an implicit mathematical form. The Van der Pauw equation used for determining the surface resistance of an electroconductive specimen was selected as a sample measurement model. With the use of the Mathematica program, it is possible to quickly determine the value of the specimen resistance. The evaluation of the uncertainty of measurement result of the surface resistance that is implied by the Van der Pauw equation is more complicated. The Monte Carlo method was applied to evaluate the uncertainty. The Monte Carlo method, including the iterative Newton algorithm, was described and realized with the use of the STATISTICA program. The effectiveness of the selected methods and developed tools was confirmed by the studies and analysis of the result of the surface resistance measurement of a specially selected woven fabric. In particular, a criterion was developed, making it possible to decide whether the electroconductive properties of the woven fabric specimen can be evaluated with the Van der Pauw method. It was shown that the selected electroconductive fabric had all characteristics typical for a Van der Pauw structure.