CO data is 0 when air is healthy

How to test the CO&Gas detectors before use?

Take the detector to approach the smoke generated by unburned paper or cigarettes,the CO value will change, and the alarm will sound "di di di" when reaching the alarm value. Please do not test it by car exhaust and burning gas in open areas, as too low CO values will not trigger sensor operation.Use a lighter to spray butane close to the buttom of the detector, the combustible gas sensor will trigger an alarm, the gas color bar will flash, and the horn will emit a beep alarm sound.