COMBINED STANDARD UNCERTAINTIES AND COVARIANCES OF OUTPUT ESTIMATES

M. Buzoianu

Abstract

Metrology, in general, and issues such as traceability and measurement uncertainty, in particular, are increasingly demanded when checking the safety of a wide range of food and agricultural products, in chemical manufacturing, environment protection, clinical chemistry as well for regulatory purposes. In many chemical quantitative analysis, the evaluation of measurement uncertainty requires the practician to look closely at all possible sources of uncertainty. Among them, data provided in calibration and correlation between the input quantities call for insight based on experience and general knowledge. Some aspects related to the estimation of measurement uncertainty and of calibration uncertainty in this field are presented.<BR />Despite the greater attention given in the recent years to covariances and correlations in metrology, they still seem to be undervalued in chemical measurements based on relative or comparative methods of measurement. Consequently, the paper describes the applicability of the variance- and covariancepropagation law in the particular case of spectrometric analysis. An example showing the magnitude of the correlation between output estimates is discussed.

Keywords

IMEKO, World Congress, estimation of uncertainty and errors in measurements

Download

IMEKO-WC-2000-UNC-P497.pdf

DOI

-

Back to the proceedings