... Petroleum Refinery, Chemical Plants, LPG stations, Boiler Rooms, Gas Stations, Paint Spray Booths, etc. Features1. Cast aluminium housing;2. Advanced ... two-stage) Low: 25% LEL / High: 50% LEL Detectable Gas 2Toxic / Poisonous gas ( H2S, CO, NH3, NO, NO2, SO2, Cl2, ... range and alarm threshold value can be adjusted. Gas Parameter list Gas TypeDetection RangeAlarm ThresholdSensor TypeNH3 (Ammonia)0-100 ...