The BESANTEK Corporation BST-MG01NO2 Nitrogen Dioxide Gas Detector may be used in underground coal mining, the petrochemical industry, environmental protection and other spaces where explosive gases may exist. The BST-MG01NO2 is specifically designed to detect Nitrogen Dioxide gas, and produces a sound and light alarm when the NO2 gas concentration in the environment is higher or lower than that of preset alarm point. This device is portable and can be also used as a fixed device.