MQ-3 Sensor

MQ-3 sensor interfacing with arduino


The MQ-3 sensor is a gas sensor module that is commonly used to detect alcohol vapour concentration in the air. It belongs to the MQ series of gas sensors developed by Hanwei Electronics.

The MQ-3 sensor is particularly useful in applications such as breath analyzers, automotive systems, and industrial safety equipment where the detection of alcohol is crucial.

MQ 3 Sensor PIN e1687199298346

Principle of Operation

The resistance value of MQ-3 is different to various kinds and various concentration gases. So, When using this component, sensitivity adjustment is very necessary. we recommend that you calibrate the detector for 0.4mg/L ( approximately 200ppm ) of Alcohol concentration in air and use the value of Load resistance ( RL) of about 200 KΩ(100KΩ to 470 KΩ).

Specifications of the MQ-3 Sensor

  • Sensing Element: Tin dioxide (SnO2).
  • Operating Voltage: 5V DC.
  • Heater Voltage: Typically around 5V.
  • Heater Resistance: Approximately 31Ω ± 3Ω.
  • Load Resistance: Around 20KΩ to 47KΩ.
  • Sensitivity:  Alcohol vapour.30 to 500 parts per million (ppm).
  • Response Time: Less than 10 seconds.
  • Operating Temperature:  -10°C to 50°C.

Advantage Of MQ-3 Sensor

  • High Sensitivity
  • Low Cost
  • Easy Integration
  • Compact and Lightweight

Disadvantage of MQ-3 Sensor

  • Cross-Sensitivity
  • Calibration Requirement
  • Environmental Interference
  • Limited Detection Range

Application Of MQ-3 Sensor

  • Breathalyzers
  • Automotive Safety
  • Home Brewing and Wine Production
  • Hospitality Industry

Example With Arduino

MQ 3 Sensor

Circuit Diagram With Arduino

Ds18B20 Sensor1111 3


Code With 16×2 LCD Display

Circuit Diagram With ESP8266

Circuit Diagram 49 e1687585589540




The MQ-3 sensor is a popular gas sensor module designed to detect alcohol vapour concentration in the air. It operates based on the principle of changes in the electrical conductivity of a tin dioxide semiconductor when exposed to alcohol molecules. With proper calibration and precautions, the MQ-3 sensor can be an effective tool for alcohol detection in various applications.



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