Chris Dimopoulos is a Senior Research Scientist and MCERTS Team Leader at NPL. He graduated with an MSc(Eng) in Environmental Engineering and Project Management from the University of Leeds. He has over ten years practical experience in the industrial emissions monitoring sector and represents the UK on a number of European and International committees on stationary source emissions. His expertise lies in stack flow measurements and was heavily involved in the formulation of EN TR 17078:2017 which provides guidance on the practical execution of flow measurements under EN ISO 16911-1:2013.
Flow measurements in industrial ducts and stacks are combined with pollutant or greenhouse gas concentrations to deduce mass emissions. These are then used to populate pollutant emission inventories and are traded under emissions trading schemes. Reference methods for flow are described in the standard EN ISO 16911-1. This standard introduced a series of improvements on previous flow standards that when combined provide critical uncertainty gains that support compliance with the EU’s Emissions Trading System (EU ETS).
The standard specifies a range of reference techniques including differential pressure devices and tracer techniques and introduced a number of performance requirements. Experience has now been gained in the use of EN ISO 16911 for a number of years. One of the key issues has been that although the performance requirements given in the standard are critical for the compliance to the highest tier of the EU ETS they have also been criticised for being difficult to interpret and achieve. In particular they are often not necessary for lower uncertainty requirement measurement objectives such as mass emission reporting (non-EU ETS) and isokinetic sampling. This is indeed an issue throughout EN ISO 16911-1 as a large proportion of the quality control specified within the standard seems to have been based on the demands of the EU ETS without taking into account that in some cases the degree of quality control may unnecessarily increase the time and cost of a measurement campaign for less demanding measurement objectives. CEN TS 17078 has been produced to address these issues and clarify elements of EN 16911-1:2013 and how certain requirements specified within it should be interpreted. It makes recommendations in regards to which requirements and performance characteristics apply to specified measurement objective(s) in order to achieve a consistent application of the Standard and allows for different degrees of quality control depending on the measurement objective and its uncertainty requirements.
This talk will review the requirements of EN 16911 and review experience in the application of the standard. The guidance in CEN TS 17078 will be explained and summarised, and an update will be given of current research activities related to flow measurement in stacks being undertaken in the EMPIR research project IMPRESS2 will also be presented.