versão impressa ISSN 1887-8571
PEREZ GRANA, R. et al. Nutritional analysis in ready meals (individual combat rations), Calculation of Uncertainty global estimated in a procedure for determination of moisture by gravimetric technique. Sanid. Mil. [online]. 2012, vol.68, n.2, pp.73-78. ISSN 1887-8571. http://dx.doi.org/10.4321/S1887-85712012000200003.
Objectives: The aim of this article was to estimate the uncertainty total for the determination of moisture in ready meals by gravimetric using data obtained in the validation process. Material and methods: Samples were analyzed by gravimetric method in certified reference material (CRM) (moisture certificate content: 61.8 ± 0.7 a 100 g.) in nested design. The combined uncertainty was estimated by applying the law of propagation of uncertainty. The expanded uncertainty was obtained by applying a coverage factor K = 2 (confidence level 95%). Bias was added to the expanded uncertainty by the approximation SUMU. Results: The repeatability and reproducibility limit for a confidence level of 95% is equal to 0.58% and 1.21% respectively. You get the following values of uncertainty: duplicate (0.12%), precision (0.44%), traceability / bias (0.39%) combined uncertainty (0.60%) and revised expanded uncertainty (1.38 %). Conclusions: Using a nested design (analyst, instrument, day, replicated), can vary the factors in an orderly manner, between each series, and intermediate precision estimate due to several factors. Calculation of a global uncertainty is an advantage in terms of simplicity, especially for laboratories with limited human and material resources. Inclusion of experimental bias not significant as a component of uncertainty tends to avoid underestimation of the uncertainty of the results.
Palavras-chave : Global uncertainty; moisture; ready meals.