The MQ-8 hydrogen gas sensor module is a device that is used to detect the presence of hydrogen gas in the air. It consists of a metal oxide semiconductor (MOS) gas sensor that is sensitive to hydrogen gas, as well as supporting circuitry that amplifies and processes the output of the sensor. The module typically includes a 4-pin connector, with the sensor connected to one of the pins and the other three pins connected to the amplifier and processing circuitry. It is often used in applications where it is important to detect the presence of hydrogen gas, such as in natural gas leak detection systems, industrial process control, and laboratory environments. The output of the module can be read by a microcontroller or other control device, which can use this information to take appropriate actions in response to the detected hydrogen gas concentration.

MQ-8 gas sensor sensitive material used in clean air conductivity is lower tin dioxide (SnO2). When the sensor is present in the environment in which the combustible gas, the sensor's conductivity increases with the concentration of combustible gases in air increases. Using a simple circuit can be converted to the change in conductivity of the gas concentration with the corresponding output signal. MQ-8 hydrogen gas sensor of high sensitivity, the monitoring of the other hydrogen-containing gas is also very satisfactory. The sensor can detect a variety of hydrogen-containing gas, in particular, city gas, is a low-cost sensors for a variety of applications.