MQ3 Alcohol Ethanol Gas Sensor Module


MQ3 Alcohol Gas Sensor module is a part of the MQ gas sensor family that can detect the concentrations of alcohol gas in the air and outputs its reading as an analog voltage. The sensor can measure concentrations of 0.04mg/L to 4mg/L. The concentration sensing range is suitable for breathalyzers. The sensor can operate at temperatures from -10 to 50°C and consumes less than 150 mA at 5 V. MQ3 gas sensor has a high sensitivity to Alcohol and has good resistance to disturb of gasoline, smoke, and vapor.

The sensor could be used to detect alcohol with different concentrations, it is low cost and suitable for various applications. The sensing material of the MQ3 gas sensor is SnO2. When the target alcohol gas exists, The sensor’s conductivity is higher along with the gas concentration rising.


MQ3 Gas Sensor Key Features

  • Sensor Type – Semiconductor
  • Easy SIP header interface
  • Compatible with most of the microcontrollers
  • Low-power standby mode
  • Requires heater voltage
  • Good sensitivity to alcohol gas
  • Fast response and High sensitivity  
  • Long life and low cost
  • Requires simple Drive circuit

MQ3 Gas Sensor Pinout

MQ3-Alcohol-Ethanol Gas-Sensor-Pinout
Pin NameDescription
VCCThis pin powers the module, typically the operating voltage is +5V
GNDUsed 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

Specifications MQ3 Gas Sensor

  • Power requirements: 5 VDC @ ~165 mA (heater on) / ~60 mA (heater off)
  • Current Consumption: 150mA
  • DO output: TTL digital 0 and 1 ( 0.1 and 5V)
  • AO output: 0.1- 0.3 V (relative to pollution), the maximum concentration of a voltage of about 4V
  • Detecting Concentration: 0.05-10mg/L Alcohol
  • Interface: 1 TTL compatible input (HSW), 1 TTL compatible output (ALR)
  • Heater consumption: less than 750mW
  • Operating temperature: 14 to 122 °F (-10 to 50°C)
  • Load resistance: 200kΩ
  • Sensitivity S: Rs(in air)/Rs(0.4mg/L Alcohol)≥5
  • Sensing Resistance Rs: 2KΩ-20KΩ(in 0.4mg/l alcohol)
  • Dimensions: 32 x 22 x 16 mm


  • Gas level over-limit alarm
  • Breathalyzer
  • Portable alcohol detector
  • Stand-alone/background sensing device
  • Environmental monitoring equipment


You can download the datasheet for MQ3 Alcohol Gas Sensor Module by clicking the link given below:

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