At many locations in plants for iron and steel production a monitoring of gas concentrations, levels or volume flow is necessary. The applications include coke production, iron production in a blast furnace, shaft furnace or rotary kiln, steel production in an electric arc or oxygen furnace as well as the control of the furnace gas composition and the emission monitoring. There are different aims for these measurements:

Carbon monoxid is formed at different sites in an iron & steel plant. Due to the toxicity of the gas a continous monitoring is indispensible. During the production of pig iron in a blast furnace or sponge iron in a shaft furnace or rotary kiln flammable gase are formed which can be used for further purposes, for exapmle for hot air generation in the hot air stoves or for generation of reformer gas for direct reduction. The process conditions of the steel production in an oxygen furnace or an electric arc furnace can be controlled by gas measurement in the exhaust gas. In addition to gas analyzers bin level indicators are used for level monitoring in the raw material silos. Finally, the exhaust gases produced during the iron or steel production have to be cleaned before they are realesed into the atmosphere. In this case dust, flow and gas monitors are used to control the compliance with emission limits.

Depending on the measuring task and the measuring point extractive measurement as well as in-situ measurement can be used in the iron & steel industry. The emissions that can be released into the environment are limited by special legislation. The devices used for this purpose often require official approval in many countries.