The LM 201A carbon monoxide detector is certified and tested according to EN 50291. The display shows temperature, carbon monoxide concentration, battery charge, operational monitoring, and alarm information. A three-color LED indicator shows the detector's status. The LED indicator has a self-diagnosis function, and a TEST button allows testing of the gas detector, a fault warning in case of malfunction, and a low battery warning. The warning system provides a warning based on the carbon monoxide concentration, with an alarm signal sounding at dangerous concentrations. False alarms are silenced for 5 minutes. Included in delivery: one LM 201A carbon monoxide detector and three 1.5V DC AA batteries. Effective detection gas: carbon monoxide Detection method: electrochemical sensor Working voltage: 4.5V DC Working environment: temperature 0~45℃ Relative humidity: 0-90%RH Static working current: 8010uA Alarm current: 45~75mA Alarm signal level: >85dB (1m distance) Power indicator: flashes once every 45 seconds Fault detection: detects once every two minutes Applicable occasions: home, hotel single rooms, warehouses, basements