The European Standard describes the quality assurance procedures related to automated measuring systems (AMS) for the determination of total mercury in waste gas, in order to meet the uncertainty requirements on measured values given by regulations, e. g. EU Directives, national or other legislation. This document is derived from EN 14181, which specifies general procedures for establishing quality assurance levels (QAL) for automated measuring systems (AMS) installed on industrial plants for the determination of the flue gas components and other flue gas parameters. It amends EN 14181 and provides guidance specific to total mercury measurements. It is only applicable in conjunction with EN 14181. The calibration and validation of mercury AMS that measure the total vapour phase mercury content is based on parallel measurements with the manual method described in EN 13211. The species of mercury (elemental Hg0 and oxidized Hg2+) and the physical occurrence (gaseous, dust-bound or within droplets) can vary significantly depending on the type of process to be monitored and this is taken into account when implementing the SRM. This document specifies requirements for the calibration and validation (QAL2), the ongoing quality assurance during operation (QAL3) and the annual surveillance test (AST) of automated measuring systems (AMS) used for monitoring total mercury emissions from stationary sources to demonstrate compliance with an emission limit value (ELV). This document is derived from EN 14181 and is only applicable in conjunction with EN 14181. This standard also specifies type testing (QAL1) requirements in Annex B that will be incorporated into EN 15267 3 when that standard is next revised. This document is applicable by direct correlation with the standard reference method (SRM) described in EN 13211.