应用物理—TDLAS技术中谐波信号的理论推导与实验研究.pdfVIP

Applied Physics 应用物理, 2012, 2, 92-97 doi:10.4236/app.2012.23016 Published Online July 2012 (/journal/app) Theoretical Derivation and Experimental Research of * Harmonic Signals Based on TDLAS Lu Che, Yanjun Ding, Zhimin Peng State Key Laboratory of Power Systems, Department of Thermal Engineering, Tsinghua University, Beijing Email: chelu06@163.com, dyj@, aspect@126.com Received: May 15th, 2012; revised: May 23rd, 2012; accepted: Jun. 1st, 2012 Abstract: In this paper, we derived the expression for the instantaneous intensity based on numerical simulation and practical experiments in tunable diode laser absorption spectroscopy, and determined the new expression of the har- monic signals in wavelength modulation spectroscopy, then we analyzed the influence to the harmonic signals caused by the phase shifts between the detected and reference signals. The transition of CO2 at 6527.64 cm–1 was selected for the practical experiments, and the experimental results indicated that, the amplitude of laser intensity modulation was invariant during the scanning process, which did not change with the average scanning laser intensity. What’s more, the amplitude and phase of the harmonic signals were influenced by the phase shifts between the detected and reference signals, which cannot be ignored in gas concentration and temperature measurements. Keywords: Tunable Diode Laser Absorption Spectroscopy (TDLAS); Wavelength Modulation Spectroscopy (WMS); Harmonic Signals TDLAS 技术中谐波信号的理论推导与实验研究* 车 璐，丁艳军，彭志敏 清华大学热能工程系，电力系统与发电设备控制与仿真国家重点实验室，北京 Email: chelu06@163.com, dyj@, aspect@126.com