Compact QEPAS sensor for trace methane and ammonia detection in impure hydrogen

Published 2012

Lei Dong Shanxi University

J. Douglas Wright Drexel University

Frank Tittel J.S. Abercombie Professor of Electrical & Computer Engineering, Rice University

DOI: 10.1007/s00340-012-4908-x

Abstract:

A compact two-gas sensor based on quartz-enhanced photoacoustic spectroscopy (QEPAS) was developed for trace methane and ammonia quantification in impure hydrogen. The sensor is equipped with a micro-resonator to confine the sound wave and enhance QEPAS signal. The normalized noise-equivalent absorption coefficients (1 σ) of 2.45× 10− 8 cm− 1 W/Hz and 9.1× 10− 9 cm− 1 W/Hz for CH 4 detection at 200 Torr and NH 3 detection at 50 Torr were demonstrated with the QEPAS sensor configuration, respectively. The influence of...

Excerpt:

The 4 4 MEMS switch was realized by combining two 1 4 switches (LightBand Mini 14, Agiltron, Inc.). The MEMs switch was controlled to direct either of the two diode lasers to the ADM via a parallel 4-bit binary code provided by the CEU...