EN 14181 is a European standard relating to the quality assurance of Automated
Monitoring Systems (AMS) used to measure emissions from processes covered by the
Waste Incineration Directive (WID) and the Large Combustion Plant Directive (LCPD).
Power generators & Waste Incinerators had to be in compliance with the directive by
The requirements of EN 14181:
There are several requirements under this standard. Firstly, the AMS should have
undergone a battery of tests to ascertain how accurate and reliable it is. This
procedure is called QAL1. There are two competent testing authorities, primarily
MCERTS and secondly TUV (Germany).
AMS that have not undergone a QAL 1 should not normally be used on plant where
compliance with EN14181 is required. This is because certain data from the QAL1
testing such as uncertainty calculations are required to enable the complex
calculations within EN 14181. However, in certain cases, the Environment Agency
is allowing operators to continue with untested AMS for a limited period of time.
However, this presents an issue when trying to determine the uncertainties required
by the standard for QAL3 calculations as these can only be derived by QAL1
Emaccs is able to check if an operator’s AMS are QAL1 certified and if not can
either, update them to a QAL 1 standard or integrate and install a package of
analysers that meet the QAL standard. We are a recognised systems integrator with
the skills to tailor a system to an operator’s legislative requirement using the best
Once an AMS is installed on site, the operator has up to six months to perform a
QAL2 analysis. This analysis will be required every 3 or 5 years (dependent on
process) with similar Annual Surveillance Tests performed in years when a QAL 2 is
not required. QAL2 comprises of an MCERTS approved testing organisation
performing a minimum of 15 tests per measurand over a period of 5 days. These
tests are called Standard Reference Methods (SRM) because the methodology of
the test is specified in a CEN standard.
In essence, the testing company performs an SRM over a given period and
produces an averaged result. The AMS also produces an average result for the
same period and these paired results are used to calculate the following:-
Certification range of the AMS for this measurand
Variability of results
Several other statistical functions including standard deviation
The calibration function is then used to correct data generated by the AMS prior to it
being used in reports etc. The Certification range determines the range in mg/Nm3
over which the AMS results are deemed to be accurate.
If the AMS fails to meet the QAL2 standard for any or all the measurands, it must
either be repaired and/or the tests repeated. This can be a very expensive exercise
and continued failure will probably result in the AMS being replaced.
Using Emaccs to help you up rate or replace your current system can drastically
reduce the possibility of a QAL2 failure and the financial consequences of this. We
can also engage an MCERTS certified testing organisation to perform the tests and
provide a project manager to oversee the whole process to help provide a
Once the initial QAL2 has been performed, every year the AMS must undergo a
QAL2 or an AST (a foreshortened QAL2) to ensure that it still remains accurate,
linear and repeatable. Prior to the test team coming to site, Emaccs can provide
high quality servicing for the AMS to ensure it enters the testing evolution in tip top
condition. Failure to pass a QAL2 or AST will result in full repeat QAL2 and the
inevitable financial consequences of this.
Once the analyser has passed QAL2 and it has commenced normal operation the
AMS must undergo regular quality assurance checks to confirm that it has not
drifted in terms of accuracy. These QA checks are termed QAL3; they consist of
injecting a zero or span sample into the AMS system to determine the AMS
response to the test gas; this is done for all measurands. The matched pairs of data
(test gas concentration and AMS output) are fed into an ongoing calculation which
creates control charts to show AMS drift.
There are 4 types of control chart that the user can use:
The chart shows when the analyser goes “out of control” and at this point the AMS
must be attended to by qualified service personnel.
The data acquired during QAL3 testing must be retained for audit purposes at the
next AST. Initiating manual zero and span checks and then manually entering the
results into control chart software is time consuming and tedious.
distributors of EmiDAS Data Acquisition & Handling Software (DAHS) developed
by G2 Data Systems Ltd; the software complies with the Environments Agency’s
MCERTS Data Management Standard and stores, presents and reports emissions
data in the required formats.
EmiDAS also provides the ability to store data points created in QAL3 tests,
automatically create all the above mentioned control charts and create a report for
the AST audit. In addition, we can build systems that automatically inject zero and
span gases at specific times. The combination of EmiDAS software and EMACCS
hardware provides an easy, simple and cost effective system for dealing with QAL3
quality assurance systems.
EN14181 can seem overcomplicated and daunting at first, but it is really effective at
ensuring that AMS perform accurately and reliably. This in turn ensures that the quality of
reporting that operators are required to produce is similarly of a high quality. EMACCS can work with you in partnership to help you through the EN14181 process by:
Upgrading non-compliant AMS
Installing state of the art, EN14181-compliant AMS
Engaging MCERTS approved testing teams
Servicing AMS and preparing them for site testing
Installing EmiDAS data acquisition and handling systems
Automating the QAL3 process.
EMACCS - Emissions Monitoring & Data Acquisition Specialists