Continuous Emission Monitoring Systems

Continuous emission monitoring systems (CEMS) measure airflow, dust, the concentration of air pollutants (such as SO2, NOx, CO, etc.), and other parameters related to emissions. Required parameters depend on the type of stationary source and local regulations. A standard CEMS consists of a sample probe, filter, sample line (umbilical), gas conditioning system, calibration gas system, and a series of gas analyzers that reflect the parameters being monitored. Typically monitored emissions include: sulfur dioxide, nitrogen oxides, carbon monoxide, carbon dioxide, hydrogen chloride, airborne particulate matter, mercury, volatile organic compounds, and oxygen. CEMS can also measure airflow, flue gas opacity, and moisture.