Continuous Emission Monitoring EN14181 - Quality and Quantity in Emissions Monitoring?

If you are an industrial process operator with an environmental permit, then you will be aware of the requirement to ensure that any continuous emissions monitoring systems (CEMs) that are installed at emission points to air are functioning correctly. Five years ago a new European standard (BS EN 14181) was introduced to provide formal quality assurance procedures to be applied to CEMs on all processes falling under the Waste Incineration (WID) and Large Combustion Plant (LCPD) Directives.

The principles of BS EN 14181 are relatively simple in that suitable monitoring equipment is installed; it is set up correctly, calibrated effectively and monitored over time to ensure the derived calibration function maintains its validity and suitable checks are made. The outcome of this is to increase both the accuracy and precision of the installed instrument, thus increasing the confidence in the results it reports and ultimately reducing the potential requirement for additional specialist monitoring to verify the performance of the process. In short, EN14181 defines three Quality Assurance Levels - QAL1, QAL2 and QAL3 - and an Annual Surveillance Test (AST). The basic structure of the QA process is shown in the flow diagram.