NCL1801 flue gas analyzer is a high-tech product that integrates data acquisition, computation, and control. The data acquisition and analysis unit is directly installed on the flue, using advanced ceramic semiconductor NOx sensors, adopting compressed air drainage sampling method, and equipped with temperature automatic control to minimize the detection response time and achieve real-time reaction of the true value of ammonia oxides. The display and control adopt embedded controllers, and after program calculation and processing, the real-time and accurate automatic adjustment of SCR denitrification ammonia supply is finally achieved. The NAM2101 flue gas analyzer is a special purpose detection instrument developed and upgraded based on the NCL1801 model. The data collection and analysis unit adopts patented sampling technology, which achieves high temperature resistance on the basis of real-time detection, and can complete accurate real-time detection and analysis of nitrogen oxides in a 1200℃ environment.