MQ135 Air Quality Detector Sensor Module


The MQ 135 Air Quality Detector Sensor Module For Arduino has lower conductivity in clean air. When the target combustible gas exists, the conductivity of the sensor is higher along with the gas concentration rising. Convert the change of conductivity to the corresponding output signal of gas concentration. The MQ135 gas sensor has a high sensitivity to Ammonia, Sulphide, and Benzene steam, also sensitive to smoke and other harmful gases. It is low cost and suitable for different applications such as harmful gases/smoke detection.


  • With Signal Output Instructions
  • The TTL Output signal is a low level
  • Analog 0 ~ 5 v voltage output, the higher the concentration, the higher the voltage
  • Color is Showing Pictures.
  • Sensitive for Benzene, Alcohol, Smoke
  • Fast Response and Recovery
  • Adjustable Sensitivity
  • Air Quality Sensor Module
  • Sensitivity to Ammonia, Sulphide, and Benzene steam
  • Signal Output Indicator
  • Output Voltage Boosts Along with the concentration of the measured gases increases


Pin NamePin Description
VccUsed to power the sensor, Generally, the operating voltage is +5V.
GroundUsed to connect the module to the system ground.
Digital OutYou can also use this sensor to get digital output from this pin, by setting a threshold value using the potentiometer.
Analog OutThis pin outputs 0-5V analog voltage based on the intensity of the gas.


Size32mm X22mm X27mm
Main chipMQ-135
Operating Voltage5V DC
TypeAnalog & Digital
Detecting Range100-1000ppm


  • Domestic Gas Alarm
  • Industrial Gas Alarm
  • Portable Gas Detector


Download the Datasheet of MQ135 Sensor from the link given below.