BS EN14181

What's New

Water Monitoring Assocation is a division of the STA


BS EN14181 Quality Assurance of AMS

It is just over 10 years since EN14181 was first published [1] and the power industry subsequently highlighted areas in which the standard needed further development [2]. A CEN Technical Report, EN/TR 15983 [3], was issued in order to provide further guidance on implementation. A new version of EN14181 was published in November 2014 in order to consolidate and extend the additional interim guidance which is to be withdrawn. Note that Continuous Emissions Monitoring (CEM) systems are referred to as Automated Measuring Systems (AMS) within the standard.

The implementation on the standard can seem quite daunting to users and the diagram below provides an over-view of the approach.


Finding the right test house

When carrying out calibration to EN14181 (QAL2) or an annual follow-up check (AST) the user must use a ISO17025 test laboratory that has been accredited to the MCERTS standard for the implementation of EN14181. The test laboratory independently measures the flue gas composition and compares this with the results from the permanent monitoring system. To locate a company visit the UKAS site and type in EN 14181 in the search box. The search can be narrowed geographically by also entering the post code of interest.

Reporting functional tests

EN 14181 specifies within QAL2 and the AST that CEMs must have a set of annual functional tests. The functional tests may be performed by the operator, test laboratory, CEMs supplier, or another third-party.

The functional tests include linearity, response time and zero / span checks.

Functional test results should be reported using a form that meets the requirements of Environment Agency Technical Guidance Note M20 and EN 14181.

The Environment Agency have offered to check functional test report form templates. If you wish to have a form checked, please send it to

The Agency have checked functional test report forms for the following companies:



CES Environmental Instruments

Environmental Scientifics Group

Exova Catalyst

Parker Procal Ltd


Quantitech Ltd


Organisations that have accreditation to ISO 17025 for completing functional tests on specific CEMs, will have had their forms checked by UKAS. This applies to the following:

Uniper Technologies