ABSTRACT
The coal spontaneous combustion has been recognized as one of the major hazards in coal mine production. The fiber optic Raman scatter-based Distributed Temperature Sensor (DTS) is an effective approach for coal spontaneous combustion monitoring, which provides a convenient means to monitor the temperature distribution of coal area over time. Recently, as the most important characteristic gas, Carbon Monoxide (CO) can be used for early detection of coal spontaneous combustion in mine goafs. In this work, a sensitive and stable CO monitoring system was developed by using a Distributed Feedback (DFB) laser operating at 2.33 μm and a Herriott-type multi-pass gas cell with a 20-m optical length, taking advantage of the in-situ monitoring, excellent accuracy and simple structure available from direct absorption spectroscopy. The results obtained have validated the potential use of such a CO monitoring system in a practical monitoring application, such as the coal spontaneous combustion monitoring.
