Some discussion about detection sensitivity of tunable diode laser absorption spectroscopic technology

Tunable diode laser absorption spectroscopic (TDLAS) technology applies the wavelength tunable characteristics of diode lasers to gain the absorp- tion spectroscopy of the selected absorption line of the target gas for the qualitative and/or quantitative analysis of the pollution gases in air.Some certain measures were generally taken to overcome the flaw of the direct absorption gas sensor in order to improve the precision of measuring when to monitor trace gas.The present situation of the TDLAS technology was outlined in this paper.The thorough discussion were done from system structure processing,the modulation and demodula- tion technology,the treatment of detection devices,the processing of the testing signal and so on many aspects in view of the emergence of domestic and foreign- based on the TDLAS technology reduced the system disturbance and raised the detection sensitivity in recent years.