La problemática del ajuste en la etapa de la calibración
- González González, Antonio Gustavo
- Sayago Gómez, Ana
- García Asuero, Agustín
ISSN: 1909-4841
Year of publication: 2006
Volume: 1
Issue: 1
Pages: 107-128
Type: Article
More publications in: Tumbaga
Sustainable development goals
Abstract
The factors, which exert an influence over the calibration process in chemical analysis, are subject of consideration. The postulates in which the least squares method are based; the goodness-of-fit of the model and the residual analysis are subject of study. This last topic is a powerful tool, which allows checking the assumptions assumed, as well as taking decisions concerning data independence or homogeneity (homocedasticity). When the variance is non-uniform (heterocedasticity), data are either weighted or a transformation is carried out. The strategies to be applied in more complex cases such as non-linear calibration curves with non-uniform variance are also analysed. Finally, the use of rational or spline functions are considered.