sec.243Main return airway and return airway in a ventilation split

### sec.243 Main return airway and return airway in a ventilation split At least 1 methane detector must be located in— each main return airway; and each return airway in a ventilation split. The detector must automatically activate a visible alarm when the general body concentration of methane detected in the return air exceeds the percentage stated in the mine’s principal hazard management plan for ventilation as the percentage that must not be exceeded before the detector activates the alarm. s 243 amd 2019 SL No. 250 s 9 (sec.243-ssec.1) At least 1 methane detector must be located in— each main return airway; and each return airway in a ventilation split. (sec.243-ssec.2) The detector must automatically activate a visible alarm when the general body concentration of methane detected in the return air exceeds the percentage stated in the mine’s principal hazard management plan for ventilation as the percentage that must not be exceeded before the detector activates the alarm. - (a) each main return airway; and - (b) each return airway in a ventilation split.