|
|
|
| A Trace-gas Concentration System Based on Photoacoustic Spectroscopy with Erbium Doped Fiber Laser and A T-type Length-regulated Photoacoustic Cell |
| ZHENG De-zhong, ZHAO Nan |
| Hebei Provincial Key Lab of Measurement Technology and Instrumentation,Yanshan University,Qinhuangdao, Hebei 066004, China |
|
|
|
|
Abstract A trace-gas concentration system is designed based on photoacoustic spectroscopy. Erbium-doped fiber laser is used as a light source for acetylene detection. A T-type length-regulated photoacoustic cell is designed as first longitudinal single reflection resonance mode. The modulation frequency is 1099 Hz.Second-harmonic detection technology is used as the basic principle of the signal processing.Triangular wave is used to modulate the light source signal.The ratio between the second harmonic coefficients and the first harmonic coefficients as the system output, and the relationship curve about impact factors has been drawn. Experimental results with different concentrations of acetylene gas show that, the detection sensitivity of the system is 9.634×10－6,and signal-to-noise ratio is 41.52 dB.
|
|
|
|
|
|
［1］ Helga H, Andrea P, Zoltan B, et al. Ammonia monitoring at ppb level using photoacoustic spectroscopy for environmental application［J］. Sensors and Actuators B,2008,134:1027-1033.
［2］Zeninari V, Parvittea B, Courtoisa D, et al.Methane detection on the sub-ppm level with a nearinfrared diode laser photoacoustic sensor［J］.Infrared Physics ＆ Technology, 2003,44: 253~261.
［3］ Sigrist M W.Trace gas monitoring by laser-photoacoustic spectroscopy ［J］.Infrared Physics & Technology, 1995,36(1):415-425.
［4］ 张景超,管立君,肖长江,等.基于谐波检测原理的双光路CH4检测研究［J］.光电子·激光, 2007, 18(12):1442-1444.
［5］ Webber M E, Baer D S, Hanson R K. Ammonia monitoring near 1.5μm with diode-laser absorption sensors［J］.Applied Optics, 2001,40(12):2031-2042.
［6］ Sogaard S, Henningsen J, Pedersen J E. Wavelength modulation of fiber lasers—a direct comparisom with DFB lasers and extended cavity lasers［C］∥SPIE, 2000, 4185: 436-439.
［7］ 王琦,于清旭.超宽带可调谐掺掺铒光纤激光器研究［J］.光电子·激光,2006,17(增刊):151-153.
［8］ 肖鸿飞,任建华.环形腔掺铒光纤激光器的理论研究［J］.中国激光.2009,36(3):653-657.
［9］Bijnen F G C, Reuss J, Harren F J M. Geometrical optimization of a longitudinal resonant photoacoustic cell for sensitive and fast trace gas detection［J］. Review of Scientific Instruments, 1996, 67(8):2914-2923.
［10］ Mikls A, Hess P, Bozki Z. Application of acoustic resonators in photoacoustic trace gas analysis and metrology ［J］. Review of Scientific Instruments,2001,72(4):1937-1955. |
|
|
|
2013, Vol. 34 
