Study of carbon monoxide detection characteristics with a tunable photoacoustic spectroscopy system

In this study, a tunable distributed-feedback (DFB) diode laser based photoacoustic spectroscopy (PAS) system was proposed for the purpose of detecting carbon monoxide CO dissolved in power transformer oil. According to the HITRAN 2008 molecular spectroscopic database, a characteristic absorption line at 6380.3012 cm ^-1 was selected as the molecular spectral line of CO gas. CO detection characteristics, namely the photoacoustic signal versus CO gas pressure ranging from 0.03 to 0.12 MPa, operating temperature ranging from 280 to 330 K, laser power in the range of 3 to 14 mW and CO concentration ranging from 300 to 2000 mL/L were measured and discussed in detail, respectively. All results indicate that the proposed PAS method may be an effective and feasible way for CO gas detection.