MQ-3 Alcohol Gas Sensor Module
The MQ-3 Alcohol Gas Sensor Module is a reliable sensor designed to detect alcohol vapor in the air. It is widely used in breathalyzer devices, alcohol detection systems, and safety monitoring projects. The sensor offers high sensitivity to alcohol concentrations and provides quick and accurate readings. It works well in various environments to ensure safety and control, making it suitable for industrial, automotive, and personal safety applications.
How It Works
This sensor uses a tin dioxide (SnO2) semiconductor that changes resistance based on the concentration of alcohol vapor in the air. When alcohol vapor increases, the sensor’s resistance decreases, causing a change in output voltage. The module outputs an analog signal proportional to the alcohol concentration, which microcontrollers like Arduino, ESP32, or Raspberry Pi can easily read. A built-in heater operates at 5V to maintain optimal sensor performance. The sensor requires a warm-up time of about 20 seconds before giving stable readings.
Key Features
Detects alcohol vapor with high sensitivity
Fast response and recovery times
Operates on 5V DC power supply
Provides analog output for easy integration with microcontrollers
Compact and lightweight design for various applications
Suitable for breathalyzers, safety alarms, and gas leak detection
Specifications
| Parameter | Value |
|---|---|
| Operating Voltage | 5 V DC |
| Sensor Type | Semiconductor (SnO2) – |
| Detection Gas | Alcohol vapor |
| Output | Analog voltage |
| Heater Voltage | 5 V DC |
| Warm-up Time | About 20 seconds |
| Response Time | Less than 10 seconds |
| Operating Temperature | -10 °C to +50 °C |
| Dimensions | About 32 mm × 20 mm |
Pin Configuration
| Pin | Name | Description |
|---|---|---|
| 1 | VCC | Power supply input (5 V DC) |
| 2 | GND | Ground |
| 3 | AO | Analog output voltage |
| 4 | DO | Digital output (threshold) |
Applications
Breathalyzer devices for alcohol detection
Safety monitoring in factories and vehicles
Alcohol vapor alarms and leak detection
Automotive and industrial safety systems
Personal and public safety applications



























