Ammonia Gas Sensor MQ137

From the shop's description

The MQ-137 is an Ammonia (NH₃) gas sensor . 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. User can convert the change of conductivity to correspond output change voltage of gas concentration through a simple circuit. MQ137 gas sensor has high sensitivity to NH3 gas, also can monitor organic amine such as trimethylamine, chloramine well. It can detect kinds of gases including ammonia and is a kind of low-cost sensor for kinds of applications Model: MQ137 Detection range: 5-500ppm Detection principle: Semiconductor Characteristics: Good sensitivity to NH3 Size: φ19×24.2 Working conditions: Loop Voltage：5±0.1V Heater Voltage：5±0.1V Heater consumption：≤950mW