Research On Ammonia Detection System With Modulation Spectrum

The nitrogen oxides（NO_X）are becoming the main pollutants.Some denitration technologies are effective in some area.In the process of denitration,the ammonia maybe escape.It is important to detected and smooth away the escaping ammonia.The modulation spectroscopy technology is executed to effectively detect escaping ammonia.The structure of a gas cell and the optical path length are key factors in a modulat.A new gas cell is proposed.It is based on the traditional White cell.The reflect cell was developed to mesure NH₃ concenteration.All the mirrors of the cell can be adjusted independently.Experiments were executed on NH₃ with the Modulation spectroscopy technology.Results show that the method is effective.The main jobs are as follows.1.The methods of escaping ammonia detection and its development are introduced.Based on the Lambert law,the Modulation spectroscopy technique on NH₃ detection as well the structure of White cell is researched.Thus,an independent-adjust NH₃ detection cell which based on optical reflection is designed.2.Depend on the measure rules,an independent-adjust NH₃ detection is designed after conducting detailed calulation and analysis.Besides,the PCB of the tempreture and presssure data collection system is designed.What’s more,a sample machine of NH₃detection is developed,which is with the launch and receive parts based on Modulation spectroscopy.3.The program of tempreture and pressure data collection is compiled,and the communication is realized;the program based on LABVIEW operating system is compiled.The data are acquired and displayed in the application.The experiment on concentration known NH₃ with the sample machine is conducted.Then,the data is delt,which is by the most reasonable calculation.The results indicate that this developed system on NH₃concentration detecting is effective.