In order to optimize all processes within the power station, from the coal bunker until the stack and the generator, the concentrations of the gas components and dust as well as the volume flow value and levels must be monitored at various points in the plant. Although the measurements have different purposes, they all have a direct effect on:

Burning coal results in solid residues (slack, ash), and dust, and particularly gaseous compounds whose concentrations have to be continuously monitored. In order to optimize the combustion process, the exact concentrations and volume flow rates of the various gases (air, flue gas, mixtures) must be known. For control and monitoring of the flue gas cleaning a continous measurement of these values is also important. The flue gas from the boiler has an extremely high dust content which has to be reduced in a downstream filter installation. Thus a continous measurement of the dust concentration is necessary to monitor both the functioning of the filter and the emission values themselves.

A mixture of in-situ and extractive techniques is often used to measure the gas components, dust, and volumetric flows in power stations. The emissions that can be released into the environment from power stations are limited by special legislation. The devices used for this purpose often require official approval in many countries.