Established in the year 2005 directive governs permissible level of pollutants which can be emitted from stationary sources and define requirements relating to automatic measuring systems to keep appropriate quality of gas monitoring. These goals are carried out by the following procedures:
QAL 1 - to demonstrate that the CEMS is suitable for the intended purpose before installation, by meeting required performance standards and the uncertainty budgets specified in the EU directives
QAL 2 - to calibrate the CEMS and determine the variability of the measured values obtained by it; so as to demonstrate the suitability of the CEMS for its application, following installation
QAL 3 - to maintain and demonstrate the required quality of the measurement results during the normal operation of the CEMS, by checking that the zero and span characteristics are consistent with those determined during QAL 1
In practice the norm EN 14181 imposes a number of obligations on manufactures, CEMS contractors and those performing the tests on CEMS.