MQ135 Gas Sensor for Air Quality
This module makes use of the MQ-135 air quality detector and hazardous gas detector chip. Other circuit components such as the LM393 analog comparator chip on this module make it easy to integrate this module into a project that can detect hazardous gases. The module requires a 5V power supply and provides a digital Logic output (1 or 0) and an analog level output(0-4V). The digital logic output is LOW(0) when no gas is detected but goes HIGH(1) when the hazardous gas concentration in the environment reaches the set threshold set via a potentiometer on the module. The analog level output provides an output voltage within the range of 0 to 4V based on the concentration of the hazardous gas in the environment; 0V for lowest concentration, 4V for maximum concentration. You can use it detects hazardous gases such as Ammonia, Nitrogen Oxide, Alcohol, Benzene, Smoke (Carbon Monoxide), Carbon Dioxide, and other air contaminants in your DIY project.
The MQ-135 device on this module uses a heating element. After initial power ON, Please wait at least 20 Seconds before reading outputs to ensure data validity.