Experimental Study on Harmonic Detection of Methane by Use of a Digital Lock-In Amplifier
DONG Lei, MA Wei-guang, YIN Wang-bao, LI Chang-yong, JIA Suo-tang
College of Physics and Electronics Engineering, Shanxi University, State Key Laboratory of Quantum Optics and Quantum Optics Devices, Taiyuan 030006, China
Abstract：The harmonic detection of methane at 6 105.369 4 cm-1 was measured by use of a digital lock-in amplifier (SR830) remotely controlled by a computer. The programme was written by Visual Basic 6.0 because it has strong function and a friendly appearance. The experimental results are in agreement with theoretical analysis, which fully confirms that a better signal-to-noise ratio (SNR) can be achieved in the high-harmonics detection of trace gases by the digital lock-in amplifier. The method can be applicable to the highly sensitive detection of pollution gases.
Key words：Lock-in amplifier;Harmonic detection;Wavelength modulation;Computer control;Methane;Absorption line
董 磊，马维光，尹王保，李昌勇，贾锁堂 . 利用数字锁相放大器对甲烷气体进行谐波探测的实验研究[J]. 光谱学与光谱分析, 2005, 25(03): 473-476.
DONG Lei, MA Wei-guang, YIN Wang-bao, LI Chang-yong, JIA Suo-tang . Experimental Study on Harmonic Detection of Methane by Use of a Digital Lock-In Amplifier . SPECTROSCOPY AND SPECTRAL ANALYSIS, 2005, 25(03): 473-476.
