“…There are numerous methods used for early detection of spontaneous combustion in underground coal mines. These include the fuzzy logic method [ 6 , 15 ], monitoring of concentration of gases produced during spontaneous combustion [ [16] , [17] , [18] , [19] , [20] , [21] , [22] ], the electromagnetic radiation technique [ 23 ], temperature measurement [ [24] , [25] , [26] ], numerical modeling [ [27] , [28] , [29] ], statistical analysis [ 30 ], the gray model [ 31 ], the analytical method [ 32 ], remote sensing [ 33 ], and the radon detection method [ 34 ]. Out of these, the most widely used technique in initial prediction of spontaneous combustion and fire status is the gas indices, such as oxides of carbon ratio (CO/CO 2 ), Willet's ratio, Jones and Trickett ratio, Graham's ratio, Young's ratio, and so on.…”