Uncertainty of emission measurements for manual and automatic reference methods. Comparison between uncertainty budget approach and inter-laboratory field test approach

The aim of this presentation is to give a comparison of the GUM approach which gives an overall uncertainty calculated through an uncertainty budget and the field approach which gives repeatability and reproducibility uncertainties. Two examples will be shown from the experiences within CEN TC264 WG16 by means of a manual reference method for SO2 and an automatic reference method for NOX.