The principle of the IV type ammonia nitrogen online analyzer is completely based on the analysis method specified in GB7478. It is an automatic online monitoring instrument that automatically completes the entire process from water sample collection to measurement value display, storage, and printing through microcomputer control. Widely used for automatic monitoring of ammonia nitrogen content in industrial, domestic sewage, and lake surface water, and also suitable for environmental management needs such as total discharge control. Ammonia nitrogen is one of the important indicators for the national control of total pollutant emissions in water environment during the 15th Five Year Plan period.