Performance evaluation of a near infrared QEPAS based ethylene sensor
Performance evaluation of a near infrared QEPAS based ethylene sensor
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DOI：
10.1007/s00340-008-3306-x
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发表时间：
2009-06
期刊：
影响因子：
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通讯作者：
S. Schilt;A. Kosterev;F. Tittel
中科院分区：
文献类型：
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作者：
S. Schilt;A. Kosterev;F. Tittel
利用光纤耦合DFB二极管激光在1.62µm光谱范围内发射，对一种基于石英增强光声光谱（QEPAS）的传感器在常压下检测痕量乙烯进行了评估。利用波长调制和二次谐波检测方案，在6177.14 cm−1的最强c2h4吸收峰上，以平均光功率为~ 15 mW，在0.7 s的数据采集时间内获得了噪声等效的4ppm c2h4 QEPAS信号。平均时间分别为70 s和700 s，检测灵敏度分别为0.5和0.3 ppm C2H4（1σ）。提出了基于QEPAS的传感器在实际条件下工作的重要特性，特别是外部温度变化的影响。此外，测量了乙烯传感器在不同配置下的响应时间，结果表明，即使没有主动气体流动，QEPAS技术也可以提供几秒范围内的响应时间。
A sensor based on quartz-enhanced photoacoustic spectroscopy (QEPAS) was evaluated for the detection of trace levels of ethylene at atmospheric pressure using a fiber coupled DFB diode laser emitting in the 1.62µm spectral range. A noise-equivalent QEPAS signal of ∼4 ppm C2H4was achieved for a 0.7 s data acquisition time using wavelength-modulation with a second-harmonic detection scheme on the strongest C2H4absorption peak at 6177.14 cm−1with an average optical power of ∼15 mW. Improved detection sensitivity of 0.5 and 0.3 ppm C2H4(1σ) was demonstrated using longer averaging time of 70 and 700 s, respectively. Important characteristics for the QEPAS based sensor operation in real-world conditions are presented, particularly the influence of external temperature variations. Furthermore, the response time of the ethylene sensor was measured in different configurations and it is shown that the QEPAS technique can provide a response time in a few seconds range even without active gas flow.