The MQ137 gas sensor detects the presence of ammonia (NH3). It is sensitive to liquids, but is also suitable for gases. The warm-up time of the sensor is short, which increases its efficiency. The breakout board enables the processing of digital (DO) and analog (AO) signals. By setting the limits using the potentiometer, a digital output can be generated, while the analog output reflects the gas intensity in its environment. Both signals provide information for the detection of ammonia with an Arduino (or a compatible board such as Dasduino). Technical specifications https://elecena.pl/product/25639918/333113-developer-boards-gas-sensor-ammonia-mq-137 2024-03-26 https://elecena.pl/product/25639918/333113-developer-boards-gas-sensor-ammonia-mq-137 2025-09-04