I. Introduction SS-2000-HG mercury emission monitoring system for flue gas is a combination of the world's advanced online analytical technology and China's environmental protection monitoring technology. It is based on the company's many years of accumulated experience in the field of gas analysis and adopts multi optical path UV atomic absorption method. The system consists of a sampling unit with heat trace, a valence converter, and an analysis and processing unit. It can realize continuous on-line automatic and accurate measurement of mercury from fixed sources of flue gas. The system uses Cold Vapor Atomic Absorption Spectrometry (CVAAS), which is the most mature and stable analytical method among many mercury analysis methods. This method can only analyze the elemental mercury (Hg0) in the vapor state. CVAAS is based on the principle of selective absorption of ultraviolet light with a wavelength of 253.7 nm using mercury vapor. The low-pressure mercury lamp emits ultraviolet light through a gas chamber filled with sample gas and directly monitors the transmitted light intensity with an optoelectronic receiver to calculate the absorbance. Within a certain concentration range, the mercury concentration is proportional to the absorbance, which is in accordance with Beer-Lambert law. At the same time, oxygen, temperature, pressure, flow rate, humidity and other parameters can be monitored. Charts are generated through the data acquisition and processing system, and data remote transmission interfaces are reserved. The monitoring data can be transmitted to all levels of environmental protection according to the HJ/T212 national standard communication protocol. department. II. Specifications 1. Detection method: Cold Vapor Atomic Absorption (CVAAS) 2. Measurement range: 0-100g/m3, 0-500g/m3 3, detection limit: 0.05g/m3 4, response time T90: