Appropriate measurement places and their importance in emission measurements - observations from the field: Sopivien mittauspaikkojen tärkeys päästömittauksissa - havaintoja kentältä

Number of emission measurement and the variety of measured compounds have increased rapidly in past years, mostly due to updated national and EU-based or other international regulations. At the same time, measured concentration levels have decreased (due to e.g BAT-AELs). Plants need to monitor their emissions with Continuous Emissions Measurement Systems (CEMS), as well as with discontinuous methods (e.g for heavy metals, PCDD/F).

Suitable and safe measurement places are one important prerequisite to guarantee the good quality emission measurement results. European standard EN 15259 “Air quality. Measurement of stationary source emissions. Requirements for measurement sections and sites and for the measurement objective, plan and report“ from year 2008 describes requirements for emission measurement places.

EN 15259 describes for example the topics that shall be taken into account when new plants are being designed. However, there are a number of existing plants where emissions are measured, either with CEMS or with discontinuous methods and where the measurement places do not always meet the specifications given in the standard. In addition, more attention should be paid to occupational safety aspects.

In this presentation we show practical examples what challenges stack testing teams still face with measurement places. Inappropriate measurement sites might compromise the reliability of the results and also, they might increase the measurement uncertainty of the result. It is the responsibility, as well as the advantage, of the plant operator to make sure that the measurement places are suitable for the measurement task, as well as safe.