Continuous Emissions Monitoring System (CEMS)


Continuous emission monitoring system (CEMS) is the total equipment necessary for the determination of a gas or particulate matter concentration or emission rate using pollutant analyzer measurements and a conversion equation, graph, or computer program to produce results in units of the applicable emission  and transmit the information to the 
CEM System Main Parts
The standard  of a sample probe, filter, sample line (umbilical), gas conditioning system, calibration gas system, and a series of gas analyzers which reflect the parameters being monitored.
sampling probe
dust concentration monitor
T,P,FLOW monitor

Typical monitored emissions include: SO2/NOX/CO/CO2/HCL/HF/ dust/flue gas flow rate/pressure/temperature.

Technically, gaseous pollutant monitoring systems have three types,In-Situ system type,Extractive type system,Dilution system .


Cool-Dry Extractive System

Sample gas is extracted and conditioned to remove moisture prior to analysis.Options:
Conditioning at the CEM shelter

Heated sample line is required to keep the wet sample above its dew point until it reaches the water removal system
Conditioning at the stack
Water is removed at the stack-no heated line-commonly used by source testers for short-term sampling

Hot-Wet Extractive System

No moisture removal -Moisture remains in the system throughout the sampling and measurement process
Sampling line,pump and analytical chamber are heated to keep wet sample gas above its dew point.Sample is analyzed hot and wet