Modelling European quality assurance procedures for analysers monitoring emissions under the EU’s Industrial Emissions Directive

A model has been created to investigate the uncertainty of a gas analyser operating according to the European Standard EN 14181, which ensures that the measurement uncertainty meets the requirements of legislation (Industrial Emissions Directive). This paper summarises the validation and initial results from the model, looking at the effect of varying the uncertainty of the reference method used to calibrate the analyser. The legislation allows the reference method an uncertainty of up to 20 %, but this will influence the quality of the calibration of the analyser. The results illustrate the problem and highlight that it becomes a significant issue when the reference method’s uncertainty is greater than 15 %, with the analyser failing its calibration almost half of the time due to poor reference performance at 20 % uncertainty. The model can be used to test future changes to legislation and can help operators to ensure that they would be able to meet such future measurement challenges.