Mining Publication: Evaluation of IYONI II Methanometers

No regular monitoring of methane is required in areas of gassy coal mines outby the mining face. Methane ignitions that have occurred in outby areas of the mine indicate the need to provide better protection to workers. Handheld methane monitors are now used by some miners to make periodic measurements of methane at the working face. The IYONI II gas detector, which is incorporated into a miner's cap lamp and worn the helmet, can continuously provide an alarm signal whenever methane levels exceed a set level. Tests were done to evaluate the performance characteristics of this methane detector by measuring response times with methane gas supplied through a calibration fixture or adaptor. Other response time tests were done with the detector in an environmental test box. Performance was also evaluated in a full-scale test gallery where face methane emission and underground ventilation were simulated. Procedures for calibration by response time measurement of the IYONI II detector have been developed. In limited testing, the IYONI II detector was found to reliably detect the presence of 1% by volume methane.