From the coal mine”gas”Speaking of early19century,Coal miners used canaries carried down the mine as a warning sign of gas leaks.(methane)leakage——The bird fainted,People then evacuated。This is the most primitive method of methane detection used by humankind.。20early 20th century,Catalytic combustion detectors have been developed.,The canary is the real”retire”。decades thereafter,Methane detection technology is constantly evolving with industrialization.,From the facts...

Optical frequency comb,As precision