... gas leak detector is a low-cost, high-performance infrared sensor detector.The instrument is reliable , easy to use , ... the alarmAfter start-up, full- function self-test of sensor , circuitry, battery integrity, sound or video alarmTechnical parameter: ... gasCO2Measuring range0~2000,5000ppm, Max to 50000ppmPerformance life of sensor more than five yearsAccuracy<±20ppm±3% Repetitive1% Resolution: ...