Monitoring networks in the USA, Canada, Korea, China and the EU have chosen Tekran (Canada)’s Model 2537B analyzer, combined with the 1130/1135 modules to provide unattended, automated, continuous atmospheric mercury speciation measurements at the part per quadrillion level. The Model 2537S is the analyzer for the Tekran Series 3300 Continuous Emission Monitor. The Series 3300 can measure total, elemental and ionic mercury in virtually any combustion source. The system is sensitive enough to measure levels at any coal fired power plant and is immune to the interferences that plague conventional mercury CEMs.