Environmental monitoring industry is an important industry for the application of standard gases. The purpose of environmental monitoring is to accurately, timely and comprehensively reflect the current situation and development trend of environmental quality, and to provide scientific basis for environmental management, pollution source control and environmental planning.

On-line monitoring technology for fixed pollution sources (CEMS)

Air quality monitoring is a part of environmental monitoring and can be divided into the following two categories:

1.Fixed pollution source monitoring (using pollution source soot (dust) online monitor and flue gas SO2, NOx online monitor)
2.Air quality monitoring (using the ambient air surface automatic monitoring system to monitor pollutants such as SO2, NOx, CO, O3, PM1 in the atmosphere

Online monitoring of pollutant discharge is the most important measure for the environmental protection department of the government to control the concentration and total amount of pollutant discharge, and it is the basis and technical support for the environmental management of the environmental protection department. Pollution sources on-line monitoring is the only feasible pollution emissions real-time dynamic monitoring technology, its main mission is to provide a variety of timely and accurate total pollution discharge of pollutants and all sorts of pollutants concentration distribution data of time and space, provide the basis for environmental law enforcement and environmental management, improve the efficiency of environmental monitoring, enhance the level of modernization of environmental monitoring.

In terms of CEMS technology itself, the measurement of particulate matter, sulfur dioxide, nitrogen oxides and their related flue gas parameters (oxygen content, temperature, flow rate, pressure, humidity), China's CEMS technology is not inferior to developed countries such as Europe and the United States.

A complete set of CEMS mainly includes four parts: particulate matter monitoring subsystem, gaseous pollutant monitoring subsystem, flue gas emission parameter monitoring subsystem, data processing and transmission subsystem.

Particulate matter monitoring subsystem: it mainly measures the smoke concentration in the flue gas.
Gaseous pollutant monitoring subsystem: it mainly monitors the pollutants existing in gaseous form such as NOx, SO2, CO and CO2 in the emission flue gas.
Flue gas emission parameter subsystem: it mainly monitors the temperature, pressure, humidity, oxygen content and other parameters of the emission flue gas, and is used to calculate the pollutant emission and convert the concentration of pollutants into the standard dry flue gas state and the concentration under the excess air coefficient stipulated in the emission standard.
Data processing and transmission subsystem: it mainly completes the collection, storage and statistical functions of measurement data, and transmits the data to the environmental supervision department according to the format required by relevant standards