The MQ-137 is an Ammonia (NH₃) gas sensor from Winsen. The sensing element is SnO2, which has lower conductivity in clean air. When NH₃ (Ammonia) gas exists, the sensor’s conductivity gets higher as the gas concentration rises. A simple circuit makes measuring this change in conductivity and turning it into data fairly straightforward, but it does require some calibration.
For easy Solderability, use our Gas Sensor Breakout Board.
