Uncertainty estimation

A calibration or testing laboratory shall have and apply a documented procedure to estimate the uncertainty of the measurements or calculated results derived from such measurements.

When the nature of the method may preclude rigorous, metrological and statistically valid estimation of uncertainty, the laboratory shall identify all the components of uncertainty and to make a reasonable estimation following the steps shown in the chart.

Since EDXRF has different quantitative approach or methodologies for the determination of element concentration, the uncertainty budget must be carried out for the specific quantitative method used.