Estimativa da Incerteza de Medição nos Ensaios de Resistência Elétrica de Fios e Cabos Elétricos para Tensões Nominais de até 450/750V

Abstract

The national market for electrical wires and cables faces the presence of products of dubious quality, with irregularities such as electrical resistance exceeding normative limits, which can lead to fires. This dissertation addresses the importance of ensuring the compliance of these products, focusing on the estimation of measurement uncertainty in electrical resistance tests for wires and cables with nominal voltages up to 450/750V. The "top-down" methodology was applied, using the Ishikawa Diagram to identify sources of uncertainty, allowing for the creation of a mathematical model to calculate the combined standard uncertainty. Tests were conducted on samples collected from factories and the market, using properly calibrated equipment such as a digital micro-ohmmeter and thermohygrometer. The results revealed that several samples did not meet the normative limits, highlighting the need to improve inspection and compliance testing. The developed mathematical model proved effective in estimating measurement uncertainty, contributing to the reliability of results and consumer safety. This study emphasizes the importance of estimating measurement uncertainty as an essential tool for improving inspection processes and ensuring that products meet safety and quality standards.