The multi-gas detector is made up of the probe and the alarm apparatus, which has found applications in the petrochemical industry with combustible gas, including petroleum, flue gas, chemistry, and oil depot. It can be used to detect gas leakage in dangerous occasions and is an important instrument to ensure production and personal safety. When there is combustible gas on the detected site, the probe will transform the gas signals into the voltage signals or current signals, and send them to the alarm. The instrument will display the concentration percentage of the lower explosive limit of combustible gases. When the concentration of combustible gases exceed the alarm level, it will give out the acousto-optic alarm signals, and the personnel on duty can immediately adopt safety measures to avoid occurrence of combustion or explosion.

The gas components in the mine represent different dangerous situations. The toxic gases include CO, CO2, and SO2, or inadequate oxygen. Under some conditions, methane might reach the concentration which might cause an explosion. Therefore, many underground gas detectors will be installed with different types of sensors, such as oxygen sensors, CO sensors, and CO2 sensors. By changing different gas detection probes, components and concentrations of different gases can be detected.