A quartz-enhanced photoacoustic spectroscopy (QEPAS) based multi-gas sensor was developed to quantify concentrations of carbon monoxide (CO), hydrogen cyanide (HCN), hydrogen chloride (HCl), and carbon dioxide (CO₂) in ambient air. The sensor consists of a compact package of dimensions 25cm x 25cm x 10cm and was designed to operate at atmospheric pressure. The HCN, CO₂, and HCl measurement channels are based on cw, C-band telecommunication-style packaged, fiber-coupled diode lasers, while the CO channel uses a TO can-packaged Sb diode laser as an excitation source. Moreover, the sensor incorporates rechargeable batteries and can operate on batteries for at least 8 hours. It can also operate autonomously or interact with another device (such as a computer) via a RS232 serial port. Trace gas detection limits of 7.74ppm at 4288.29cm^-1 for CO, 450ppb at 6539.11 cm^-1 for HCN, 1.48ppm at 5739.26 cm^-1 for HCl and 97ppm at 6361.25 cm^-1 for CO₂ for a 1sec average time, were demonstrated.

Date Published: 24 January 2011
PDF: 8 pages
Proc. SPIE 7945, Quantum Sensing and Nanophotonic Devices VIII, 79450R (24 January 2011); doi: 10.1117/12.875108

Published in SPIE Proceedings Vol. 7945:
Quantum Sensing and Nanophotonic Devices VIII
Manijeh Razeghi; Rengarajan Sudharsanan; Gail J. Brown, Editor(s)