Estudo e elaboração de carta controle e incerteza de medição para análise de Demanda Química de Oxigênio (DQO)

Abstract

Nowadays, the market increasingly demands that companies be able to provide quality services to their customers, making laboratory accreditation under ISO 17025 highly important. One of the key requirements for the competence of testing laboratories includes ensuring equipment conformity and managing measurement uncertainty, thereby enhancing reliability. In this context, a website for control chart development was created using the platform websim.ai, which employs artificial intelligence to rapidly generate applications and tools through simple commands. Additionally, a study was conducted to investigate the main sources of uncertainty associated with the test and their contribution to measurement uncertainty. The procedures recommended in the Eurachem, GUM, and ISOBudget guides were followed. Based on the obtained results, repeatability calculations were performed, demonstrating that it is the primary source of uncertainty contributing to measurement uncertainty in the test. The final measurement uncertainty was determined to be (320 ± 19.6) mgO₂L⁻¹, with k=2 under a normal distribution and a 95.5% confidence level.