MQ-135 Gas sensor air quality module

The AZ Delivery MQ-135 air quality sensor as a ready-to-connect module for Raspberry Pi

Easy to use sensor for measuring the concentration of various toxic gases such as benzone, alcohol, smoke as well as impurities in the air. The MQ-135 measures gas concentration from 10 to 1000ppm and is ideal for detecting a gas leak, as a gas alarm, or for other robotics and microcontroller projects. The MQ series sensors use a small heating element with an electronic chemical sensor. They are sensitive to a wide range of gases and are suitable for indoor use. The sensor has high sensitivity and fast response time, but it takes a few minutes to output accurate readings because the sensor has to heat up first. The measured values of the sensor are output as an analog value, which can be easily evaluated with a microcontroller. This sensor is ready for connection to a microcontroller, such as an Arduino board. For use with a Raspberry Pi, an AD converter is also required. Pinout:

VCC - power supply 5V GND - Ground connection AOUT - Analog Output DOUT - Digital Output

For setting the threshold value the module has a potentiometer. At the digital pin the sensor only outputs a 0 or 1, depending on whether the set threshold value is exceeded.  Caution: The sensor becomes warm during operation!

Details:

Resolution: 10 ~ 1000ppm Sensitive resistance: 2kΩ to 20kΩ in 100ppm CO Accuracy: ≥ 3% Reaction time: ≤ 1s AN response time after switching on: ≤ 30s Heating current: ≤ 180mA Heating voltage: 5.0V ± 0.2V / 1.5 ± 0.1V Input voltage: 5V Heating supply approx.: 350mw Dimensions: approx. 30mm (length) * 20mm (width)