Research on Multi-point Measurement System of Mine Gas Based on TDLA

Tunable Diode Laser Absorption Spectroscopy (TDLAS) technology combines the advantages of wavelength modulation technology and direct absorption spectroscopy technology, and the system achieves highly sensitive and full-range detection of methane gas concentrations. In the system, only the pure optical methane probe is positioned under the mine, which establishes connectivity with the host computer on the surface through the optical fiber. This setup enables the simultaneous detection of 16 channels of methane gas through time-sharing multiplexing technology. Experimental results demonstrate a measurement error of less than ±6.0×10 −4 at low concentrations (0∼1%) and within ±6% of the true value at high concentrations under normal temperature and pressure conditions. The full-range linear fit attains 0.9998. According to the one-fold standard deviation, the minimum detection lower limit of the system stands at 68.36 ppm and the measured gas concentrations across different channels of the methane probes remain consistent inhe same environment. This technology provides a new solution for continuous, accurate, and multi-point monitoring of mine gas.