A Sensitive and Reliable Carbon Monoxide Monitor for Safety-Focused Applications in Coal Mine Using a 2.33-$\mu$ m Laser Diode

Abstract

In this paper, a stable and reliable CO monitoring system with high sensitivity (at sub-ppm level) was designed and demonstrated with particular reference to use in the mining industry, tailoring the design specifically for forecasting spontaneous combustion, a major hazard to miners. The design uses the familiar approach of direct absorption spectroscopy approach, but showing novelty in the tailoring of this approach to the mining industry, for use in situ. An appropriate strong CO absorption line is used to help eliminate the cross interferences expected from gases present in ambient air, with several preferred CO absorption lines selected and investigated, therefore choosing a distributed feedback (DFB) laser operating at a wavelength of 2330.18 nm as the excitation source. Through a detailed investigation, a minimum detection limit of ~0.2 ppm and a measurement precision (σ) of 6.3 ppb were achieved with a data updating rate of 6.6 s/point. Further in tests for the mining industry, a long-term continuous monitoring evaluation was carried out, demonstrated the excellent stability and reliability of the CO monitoring system. The results obtained have validated the potential of this design of a CO monitoring system for practical monitoring applications underground to enhance safety in the mining industry.

A Portable Environmental Data-Monitoring System for Air Hazard Evaluation in Deep Underground Mines

“…The idea of the electronic nose concept has been proposed in [53]. CO detectors are based on a laser diode proposed in [54]. Statistical analysis of CO and H 2 S in deep underground mines for long-term measurements have been studied in [3,4].…”

A Review on Mine Fire Prevention Technology and Theory Based on Bibliometric Analysis

“…The method that utilizes satellite thermal infrared (TIR) remote sensing to determine the thermal anomalies of underground coal fires has been widely adopted [18]. Moreover, fiberoptic temperature measurement technology has been utilized for temperature monitoring in mining areas [19].…”