CEM - Abstract

Abstract Title: Determining the uncertainty in reported automated measuring system results
Presenter Name: Mr Rod Robinson
Co-authors:Ms Hannah Cheales
Mr Thomas Smith
Company/Organisation: National Physical Laboratory
Country: United Kingdom

Abstract Information :

The quality assurance of automated measuring systems (AMS) operated to report emissions under regulation such as the Industrial Emissions Directive (IED) is defined within a suite of European Standards including EN 14181, EN 15267 and EN 17255 and the suite of standard reference methods (SRMs) against which the AMS is calibrated. These provide the framework in which AMSs are assessed, calibrated and how the data are handled. There are a number of quality criteria within the IED and the CEN standards, for example maximum permissible uncertainties for the SRM, and criteria on the standard deviation of the calibration function in EN14181. The IED, which is currently under revision, defines quality criteria related to the uncertainty of the reported AMS results (expressed as confidence intervals), and this is critical when comparing the AMS results to emission limits. The revision of the IED is likely to firm up this requirement. There is, however, no defined procedure to determine the uncertainty of the AMS results, and member states have adopted various inconsistent approaches. This presentation presents an assessment of the uncertainty in AMS results, for individual short term and daily averages. It describes the sources of uncertainty and explains the way these influence the AMS results. A calculation approach is given and comparisons is made to a comprehensive Monte Carlo model of the EN 14181 pro Potential routes forward to develop guidance on assessing the uncertainty of AMS results will be given.