What is a Continuous Emission Monitoring System?

What is a Continuous Emission Monitoring System?

What is a Continuous Emission Monitoring System?

A Continuous Emission Monitoring System, or CEMS, utilizes analytical equipment and instruments that continuously measure the concentrations of certain pollutants, such as NOx and SO2, of the stack exhaust gas to the atmosphere, its volumetric flow, and report their emissions set forth by EPA and local air quality management agencies such as South Coast Air Quality Management District (SCAQMD).

The measurement data are to be recorded at least every 15 minutes and the 1-hour average emissions data are to be reported in an electronic format. To ensure they are operating properly, the CEMS is subject to the mandated quality assurance tests such as the daily calibration error check.