Mercury Analysis – CMM SYSTEM

The Gasmet Continuous Mercury Monitoring (CMM) system uses Cold Vapor Atomic Fluorescence for the detection of elemental mercury at very low concentrations. The system complies with the requirements set in EN15267-3 and is certified for the concentration range from 0 to 5 µg/m³. It holds QAL1 certification (TÜV https://qal1.de/en/hersteller/gasmet.htm and MCERTS https://www.csagroupuk.org/).

Photons

Cold Vapor Atomic Fluorescence is a technique where mercury atoms in the gas sample are excited by absorbing a photon from a UV light source. This excited state is unstable, and the atom quickly returns to its ground state. During this return, it emits a photon in all directions with energy equal to the absorbed photon. By placing a detector at a 90° angle relative to the light source, only light resulting from fluorescence is measured, without any contribution from the UV light source. The detector is a photon-counting module that only detects photons emitted by the Hg atoms.

What does a CMM system consist of?

The CMM system consists of a dilution probe, heated sample line, mercury analyzer, and a nitrogen generator to produce the required dilution gas, along with a test gas generator. The dilution gas is used to reduce cross-interference and quenching effects from SO₂ and O₂ by a factor of 50. The system operates fully automatically and performs the necessary calibrations at user-defined intervals.