The gas grade appraising in the coal mine is a main approach to estimate whether a coal mine is a low or high gas mine,or coal &gas outburst one,and to prevent gas explosion and mine firing.

• 矿井瓦斯等级鉴定是确定煤矿属于低瓦斯矿井、高瓦斯矿井还是煤与瓦斯突出矿井以及预防煤矿瓦斯爆炸危险和矿井自然发火危险等的一个重要手段。