Sensitivity: Methane 50 ppm; Sensor type: Low power semiconductor; Warm-up time: about 60 seconds; Response time: 2s; Detector Length: 16 inch; Powered by 3 x Type-C batteries (included); Operating temperature: 0~50'C; Operating humidity: 10%~90%RH; Press the button to "On" position, yellow light on when battery is full; The machine warm up for approximately one minute and automatic to zero adjustment; Approach the probe to test area, issued a "tick" sound accompanied by warning lights flashing after measuring the combustible gas meter ; If the environment is noisy, you can use a headset; Please remove battery if long time non-use.