This module is

made using Alcohol Gas Sensor MQ3. It is a low cost semiconductor sensor which can detect the presence of alcohol gases at concentrations from 0.05 mg/L to 10 mg/L. The sensitive material used for this sensor is SnO₂, whose conductivity is lower in clean air. It’s conductivity increases as the concentration of alcohol gases increases. It has high sensitivity to alcohol and has a good resistance to disturbances due to smoke, vapor and gasoline. This module provides both digital and analog outputs. Threshold level for digital output can be easily adjusted using the preset on the board. MQ3 alcohol sensor module can be easily interfaced with Microcontrollers, Arduino Boards, Raspberry Pi etc.

Features:

• Low Cost
• Fast Response
• Stable and Long Life
• Good Sensitivity to Alcohol Gas
• Both Digital and Analog Outputs
• On-board LED Indicator

Technical Data:

• Measuring range: 0.04 mg/L – 4 mg/L
• Operating Voltage : 5V ±0.1
• LED indicating the operation of the sensor
• Analog and digital output
• Pins: goldpin connectors, 2.54 mm pitch
• Dimensions: 35 x 22 x 30 mm
• It has mounting holes with diameter: 3.2 mm

Pin Out:

• VCC – Input Power Supply
• GND – Supply Ground
• DO – Digital Output
• AO – Analog Output

The digital output D0

With the help of placed on the reverse side of the board, potentiometer, set is the threshold, exceeding of which, causes the output D0 changing from a high to a low status. The pin D0 can be linked directly with a microcontroller or commissioning set, including Arduino, or for example,a module with a buzzer, which will signal a too low or too high levelof alcohol in the air.

Analog output A0

The sensor has an analog output A0, which must be connected to the pin of the converter A/D (analog input in Arduino). This will allow you to measure the proportional voltage signal and more accurately determine the level of alcohol.

Applications:

• Vehicle Alcohol Detector
• Portable Alcohol Detector