... LEL / High: 50% LEL Detectable Gas 2Toxic / Poisonous gas ( H2S, CO, NH3, NO, NO2, SO2, Cl2, ClO2, O3, etc ... -50.0 PPM1.0 PPM / 2.0 PPMH2 (Hydrogen)0-1000 PPM50 PPM / 100 PPMCH2O (Formaldehyde)0- ... -30.0%VOL18.5%VOL / 23.5%VOLH2S (Hydrogen Sulfide)0-100 PPM10 PPM / 20 PPMHCl (Chlorine Hydride)0 ... CombustionsensorC3H8 (Propane)0-100%LEL25%LEL / 50%LELH2 (Hydrogen)0-100%LEL25%LEL / 50%LELNH3 (Ammonia)0-100 ...