... % LEL / High: 50% LEL Detectable Gas 2Toxic / Poisonous gas ( H2S, CO, NH3, NO, NO2, SO2, Cl2, ClO2, O3, etc. )Measuring RangeRefer ... to the gas parameter list (e.g. CO: 0-500 ppm)Alarm ThresholdRefer to the gas parameter list ... (e.g. CO: 35 ppm / 70 ppm)Detectable Gas 3Oxygen (O2)Measuring Range0 ...