... and toxic gases. It is suitable for combustible and toxic gas leakage detection in underground pipe or mines, and keeps the ... operation;Explosive proof housingGas Detected:combustible gas(CH4,C3H8,H2)and toxic gas, oxygen, Other rare toxic gas like NO,PH3,NH3,NO2,HCN ... ,SO2 PH3,NH3,NO2,SO2 LCD CO Portable gas ...