Gas leak alarm is a very important gas safety equipment, and it is the last guarantee for the safe use of city gas. The alarm detects the low-concentration combustible gas in the surrounding environment through the gas sensor, and transmits the detection signal to the controller or control circuit in analog or digital quantity through the sampling circuit. When the concentration of combustible gas exceeds the value set in the controller or control circuit, the controller sends out an alarm signal or performs actions such as closing the gas valve through the actuator or execution circuit.

The sensors for detecting combustible gas in combustible gas alarm mainly include oxide semiconductor sensors, catalytic combustion sensors, hot wire gas sensors and a few other types of sensors, such as chemical battery sensors.

These sensors all produce chemical reactions or electrochemical reactions on the sensor surface by adsorbing combustible gases in the surrounding environment, which leads to changes in the electrical and physical characteristics of the sensors. Gas leak alarms are widely used in urban security, residential quarters, factories, companies, schools, families, villas, warehouses, resources, petroleum, chemical industry, gas transmission and distribution and many other fields.