Sensitive material of MQ137 gas sensor is SnO2, which with lower conductivity in clean air. When NH3 gas exists, the sensor’s conductivity gets higher along with the gas concentration rising. Users can convert the change of conductivity to correspond output signal of gas concentration through a simple circuit.
MQ137 gas sensor has high sensitivity to NH3 gas, also can monitor organic amine such as trimethylamine, cholamine well. It can detect kinds of gases including ammonia and is a kind of low-cost sensor for kinds of applications.
It is widely used in domestic NH3 gas alarm, industrial NH3 gas leakage alarm, portable NH3 gas detector.